Computer Methods and Devices for Detecting Kidney Damage
Methods and devices for diagnosing, monitoring, or determining a renal disorder in a mammal are described. In particular, methods and devices for diagnosing, monitoring, or determining a renal disorder using measured concentrations of a combination of three or more analytes in a test sample taken from the mammal are described.
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This application takes priority to U.S. Provisional Patent Application No. 61/327,389, filed Apr. 23, 2010 and U.S. Provisional Patent Application No. 61/232,091, filed Aug. 7, 2009, and both entitled Methods and Devices for Detecting Kidney Damage, the entire contents of which are incorporated herein by reference, and is related to U.S. Patent Application Nos. [Not Yet Assigned], entitled Methods and Devices for Detecting Obstructive Uropathy and Associated Disorders, Methods and Devices for Detecting Kidney Damage, Devices for Detecting Renal Disorders, Methods and Devices for Detecting Kidney Transplant Rejection, Methods and Devices for Detecting Diabetic Nephropathy and Associated Disorders, and Methods and Devices for Detecting Glomerulonephritis and Associated Disorders, Attorney Docket Nos. 060075-, filed on the same date as this application, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTIONThe invention encompasses methods and devices for diagnosing, monitoring, or determining a renal disorder in a mammal. In particular, the present invention provides methods and devices for diagnosing, monitoring, or determining a renal disorder using measured concentrations of a combination of three or more analytes in a test sample taken from the mammal.
BACKGROUND OF THE INVENTIONThe urinary system, in particular the kidneys, perform several critical functions such as maintaining electrolyte balance and eliminating toxins from the bloodstream. In the human body, the pair of kidneys together process roughly 20% of the total cardiac output, amounting to about 1 L/min in a 70-kg adult male. Because compounds in circulation are concentrated in the kidney up to 1000-fold relative to the plasma concentration, the kidney is especially vulnerable to injury due to exposure to toxic compounds.
In the pharmaceutical industry, drug-induced kidney injury is a major cause for delay during the development of candidate drugs. Historically, regulatory agencies have required drug companies to provide results of blood urea nitrogen (BUN) and serum creatinine tests, two common diagnostic tests for renal function, to address concerns of potential kidney damage as part of the regulatory approval process. However, these diagnostic tests typically detect only late signs of kidney damage and provide little information as to the location of kidney damage.
In addition to injuries resulting from exposure to drugs or other toxic compounds, kidney damage may also result from renal disorders such as kidney trauma, nephritis, kidney cancer, and kidney transplant rejection. Kidney damage may also occur as a secondary side effect of more systemic diseases such as diabetes, hypertension, and autoimmune diseases. Existing diagnostic tests such as BUN and serum creatine tests typically detect only advanced stages of kidney damage. Other diagnostic tests such as kidney tissue biopsies or CAT scans have the advantage of enhanced sensitivity to earlier stages of kidney damage, but these tests are also generally costly, slow, and/or invasive.
A need exists in the art for a fast, simple, reliable, and sensitive method of detecting a renal disorder. The detection of the early signs and locations of drug-induced kidney damage would be useful in guiding important decisions on lead compounds and dosage. In a clinical setting, the early detection of kidney damage would help medical practitioners to diagnose and treat kidney damage more quickly and effectively.
SUMMARY OF THE INVENTIONThe present invention provides computer methods and devices for diagnosing, monitoring, or determining a renal disorder in a mammal. In particular, the present invention provides methods and devices for diagnosing, monitoring, or determining a renal disorder using measured concentrations of a combination of three or more analytes in a test sample taken from the mammal.
One aspect of the present invention provides a method for diagnosing, monitoring, or determining a renal disorder in a mammal that includes providing a test sample that includes a sample of bodily fluid taken from the mammal, and determining the presence of a combination of three or more sample analytes in the test sample. The analytes in the test sample may include but are not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. The combination of sample analytes is compared to the entries of a dataset in which each entry includes a combination of three or more diagnostic analytes reflective of a particular renal disorder. The particular renal disorder of the mammal is identified as the renal disorder in the database having the combination of diagnostic analytes that essentially match the combination of sample analytes.
In another aspect, a method for diagnosing, monitoring, or determining a renal disorder in a mammal is provided that includes providing a test sample that includes a sample of bodily fluid taken from the mammal and determining a combination of sample concentrations for three or more sample analytes in the test sample. The analytes may include but are not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. The combination of sample concentrations is compared to the entries of a dataset in which each entry includes a particular renal disorder and a list of three or more minimum diagnostic concentrations indicative of the particular renal disorder. Each minimum diagnostic concentration is the maximum concentration of a range of analyte concentrations for a healthy mammal. A matching entry is determined in which all minimum diagnostic concentrations are less than the corresponding sample concentrations, and an indicated renal disorder is identified as the particular renal disorder of the matching entry.
In yet another aspect, a method for diagnosing, monitoring, or determining a renal disorder in a mammal is provided that includes providing a test sample that includes a sample of bodily fluid taken from the mammal and determining a combination of sample concentrations consisting of the concentrations of calbindin, clusterin, CTGF, GST-alpha, KIM-1, and VEGF in the test sample. The combination of sample concentrations is compared to the entries of a data set in which each entry includes a particular renal disorder and a list of three or more minimum diagnostic concentrations indicative of the particular renal disorder. A matching entry is determined in which all minimum diagnostic concentrations are less than the corresponding sample concentrations, and an indicated renal disorder is identified as the particular renal disorder of the matching entry.
In still another aspect, a method for diagnosing, monitoring, or determining a renal disorder in a mammal is provided that includes providing a test sample that includes a sample of bodily fluid taken from the mammal and determining a combination of sample concentrations consisting of the concentrations of beta-2 microglobulin, cystatin C, NGAL, osteopontin, and TIMP-1 in the test sample. The combination of sample concentrations is compared to the entries of a data set in which each entry includes a particular renal disorder and a list of three or more minimum diagnostic concentrations indicative of the particular renal disorder. A matching entry is determined in which all minimum diagnostic concentrations are less than the corresponding sample concentrations, and an indicated renal disorder is identified as the particular renal disorder of the matching entry.
In an additional aspect, a method for diagnosing, monitoring, or determining a renal disorder in a mammal is provided that includes providing a test sample that includes a sample of bodily fluid taken from the mammal and determining a combination of sample concentrations consisting of the concentrations of alpha-1 microglobulin, THP, and TFF-3 in the test sample. The combination of sample concentrations is compared to the entries of a data set in which each entry includes a particular renal disorder and a list of three or more minimum diagnostic concentrations indicative of the particular renal disorder. A matching entry is determined in which all minimum diagnostic concentrations are less than the corresponding sample concentrations, and an indicated renal disorder is identified as the particular renal disorder of the matching entry.
In yet another aspect, a method for diagnosing, monitoring, or determining a renal disorder in a mammal is provided. The method includes providing a test sample comprising a sample of bodily fluid taken from the mammal and determining the concentrations of three or more sample analytes in a panel of biomarkers in the test sample. The sample analytes may be selected from the group consisting of alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. Diagnostic analytes are then identified in the test sample, wherein the diagnostic analytes are the sample analytes whose concentrations are statistically different from concentrations found in a control group of humans who do not suffer from a renal disorder. The combination of diagnostic analytes are compared to a dataset comprising at least one entry, wherein each entry of the dataset comprises a combination of three or more diagnostic analytes reflective of a particular renal disorder. The particular renal disorder in the list is identified as the renal disorder having the combination of diagnostic analytes that essentially match the combination of sample analytes.
An additional aspect provides a computer readable media encoded with an application that includes modules executable by a processor and configured to diagnose, monitor, or determine a renal disorder in a mammal. An analyte input module receives three or more sample analyte concentrations that may include alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. A comparison module compares each sample analyte concentration to an entry of a renal disorder database, where each entry includes a list of minimum diagnostic concentrations reflective of a particular renal disorder. An analysis module determines a most likely renal disorder by combining the particular renal disorders identified by the comparison module for all of the sample analyte concentrations.
Yet another aspect provides a system for diagnosing, monitoring, or determining a renal disorder in a mammal that includes a database to store a plurality of renal disorder database entries as well as a processing device that includes a renal disorder diagnosis application containing modules executable by the processing device. The modules of the renal disorder diagnosis application include an analyte input module to receive three or more sample analyte concentrations selected from the group consisting of alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. Another module, the comparison module, compares each sample analyte concentration to an entry of the renal disorder database. Each entry of the renal disorder database contains a list of minimum diagnostic concentrations reflective of a particular renal disorder. An analysis module determines a most likely renal disorder by combining the particular renal disorders identified by the comparison module for all of the sample analyte concentrations.
An aspect provides a device for diagnosing, monitoring, or determining a renal disorder in a mammal that includes three or more antibodies and a plurality of indicators attached to each of the antibodies. The antigenic determinants of the antibodies are analytes associated with a renal disorder including but not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF.
Another aspect provides a device for diagnosing, monitoring, or determining a renal disorder in a mammal that includes three or more capture antibodies, three or more capture agents, three or more detection antibodies, and three or more indicators. The antigenic determinants of the capture antibodies are analytes associated with a renal disorder including but not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. One of the capture agents is attached to each of the capture antibodies, and includes an antigenic moiety. The antigenic determinant of the detection antibodies is the antigenic moiety. Each of the indicators is attached to one of the detection antibodies.
A final aspect provides a method for diagnosing, monitoring, or determining a renal disorder in a mammal that includes providing an analyte concentration measurement device that includes three or more detection antibodies, in which each detection antibody includes an antibody coupled to an indicator. The antigenic determinants of the antibodies are sample analytes associated with a renal disorder including but not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. A test sample that contains three or more sample analytes and a bodily fluid taken from the mammal is provided and contacted with the detection antibodies. The detection antibodies are allowed to bind to the sample analytes. The concentrations of the sample analytes are determined by detecting the indicators of the detection antibodies bound to the sample analytes in the test sample. The concentrations of each sample analyte are compared to a corresponding minimum diagnostic concentration reflective of a particular renal disorder.
Other aspects and iterations of the invention are described in more detail below.
It has been discovered that a multiplexed panel of up to 16 biomarkers may be used to detect early renal damage and pinpoint the location of renal damage within the kidney. The biomarkers included in the multiplexed panel are analytes known in the art that may be detected in the urine, serum, plasma and other bodily fluids of mammals. As such, the analytes of the multiplexed panel may be readily extracted from the mammal in a test sample of bodily fluid. The concentrations of the analytes within the test sample may be measured using known analytical techniques such as a multiplexed antibody-based immunological assay. The combination of concentrations of the analytes in the test sample may be compared to empirically determined combinations of minimum diagnostic concentrations and combinations of diagnostic concentration ranges associated with healthy kidney function or one or more particular renal disorders to determine whether a renal disorder is indicated in the mammal. The potentially large number of combinations of diagnostic analyte concentrations makes possible a wide range of diagnostic criteria that may be used to identify a variety of renal disorders and pinpoint the location in the kidney of a renal injury, using a single multiplexed assay to evaluate a single test sample.
As used herein, the term “renal disorder” includes, but is not limited to glomerulonephritis, interstitial nephritis, tubular damage, vasculitis, glomerulosclerosis, analgesic nephropathy, and acute tubular necrosis. In another embodiment, the multiplexed analyte panel identifies secondary kidney damaged caused by exposure to a toxic compound including but not limited to therapeutic drugs, recreational drugs, contrast agents, medical imaging contrast agents, and toxins. Non-limiting examples of therapeutic drugs may include an analgesic (e.g. aspirin, acetaminophen, ibuprofen, naproxen sodium), an antibiotic (e.g. an aminoglycoside, a beta lactam (cephalosporins, penicillins, penems), rifampin, vancomycin, a sulfonamide, a fluoroquinolone, and a tetracycline), or a chemotherapy agent (e.g. Cisplatin (Platinol®), Carboplatin (Paraplatin®), Cytarabine (Cytosar-U®), Gemtuzumab ozogamicin (Mylotarg®), Gemcitabine (Gemzar®), Melphalan (Alkeran®), Ifosfamide (Ifex®), Methotrexate (Rheumatrex®), Interleukin-2 (Proleukin®), Oxaliplatin (Eloxatin®), Streptozocin (Zanosar®), Pemetrexed (Alimta®), Plicamycin (Mithracin®), and Trimetrexate (Neutrexin®). In yet another embodiment, the kidney damage may be due to kidney stones, ischemia, liver transplantation, heart transplantation, lung transplantation, or hypovolemia. In still another embodiment, the multiplexed analyte panel identifies kidney damage caused by disease including but not limited to diabetes, hypertension, autoimmune diseases including lupus, Wegener's granulomatosis, Goodpasture syndrome, primary hyperoxaluria, kidney transplant rejection, sepsis, nephritis secondary to any infection of the kidney, rhabdomyolysis, multiple myeloma, and prostate disease.
One embodiment of the present invention provides a method for diagnosing, monitoring, or determining a renal disorder in a mammal that includes determining the presence or concentration of a combination of three or more sample analytes in a test sample containing the bodily fluid of the mammal. The measured concentrations of the combination of sample analytes is compared to the entries of a dataset in which each entry contains the minimum diagnostic concentrations of a combination of three of more analytes reflective of a particular renal disorder. Other embodiments provide computer-readable media encoded with applications containing executable modules, systems that include databases and processing devices containing executable modules configured to diagnose, monitor, or determine a renal disorder in a mammal. Still other embodiments provide antibody-based devices for diagnosing, monitoring, or determining a renal disorder in a mammal.
The analytes used as biomarkers in the multiplexed assay, methods of diagnosing, monitoring, or determining a renal disorder using measurements of the analytes, systems and applications used to analyze the multiplexed assay measurements, and antibody-based devices used to measure the analytes are described in detail below.
I. Analytes in Multiplexed AssayOne embodiment of the invention measures the concentrations of at least three, six, or preferably sixteen biomarker analytes within a test sample taken from a mammal and compares the measured analyte concentrations to minimum diagnostic concentrations to diagnose, monitor, or determine kidney damage in a mammal. In this aspect, the biomarker analytes are known in the art to occur in the urine, plasma, serum and other bodily fluids of mammals. The biomarker analytes are proteins that have known and documented associations with early kidney damage in humans. As defined herein, the biomarker analytes may include but are not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, VEGF A, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, GST-mu, EGF, and cortisol. A description of some of the biomarker analytes are given below.
(a) Alpha-1 Microglobulin (A1M)Alpha-1 microglobulin (A1M, Swiss-Prot Accession Number P02760) is a 26 kDa glycoprotein synthesized by the liver and reabsorbed in the proximal tubules. Elevated levels of A1M in human urine are indicative of glomerulotubular dysfunction. A1M is a member of the lipocalin super family and is found in all tissues. Alpha-1-microglobulin exists in blood in both a free form and complexed with immunoglobulin A (IgA) and heme. Half of plasma A1M exists in a free form, and the remainder exists in complexes with other molecules including prothrombin, albumin, immunoglobulin A and heme. Nearly all of the free A1M in human urine is reabsorbed by the megalin receptor in proximal tubular cells, where it is then catabolized. Small amounts of A1M are excreted in the urine of healthy humans. Increased A1M concentrations in human urine may be an early indicator of renal damage, primarily in the proximal tubule.
(b) Beta-2 Microglobulin (B2M)Beta-2 microglobulin (B2M, Swiss-Prot Accession Number P61769) is a protein found on the surfaces of all nucleated cells and is shed into the blood, particularly by tumor cells and lymphocytes. Due to its small size, B2M passes through the glomerular membrane, but normally less than 1% is excreted due to reabsorption of B2M in the proximal tubules of the kidney. Therefore, high plasma levels of B2M occur as a result of renal failure, inflammation, and neoplasms, especially those associated with B-lymphocytes.
(c) CalbindinCalbindin (Calbindin D-28K, Swiss-Prot Accession Number P05937) is a Ca-binding protein belonging to the troponin C superfamily. It is expressed in the kidney, pancreatic islets, and brain. Calbindin is found predominantly in subpopulations of central and peripheral nervous system neurons, in certain epithelial cells involved in Ca2+ transport such as distal tubular cells and cortical collecting tubules of the kidney, and in enteric neuroendocrine cells.
(d) ClusterinClusterin (Swiss-Prot Accession Number P10909) is a highly conserved protein that has been identified independently by many different laboratories and named SGP2, S35-S45, apolipoprotein J, SP-40, 40, ADHC-9, gp80, GPIII, and testosterone-repressed prostate message (TRPM-2). An increase in clusterin levels has been consistently detected in apoptotic heart, brain, lung, liver, kidney, pancreas, and retinal tissue both in vivo and in vitro, establishing clusterin as a ubiquitous marker of apoptotic cell loss. However, clusterin protein has also been implicated in physiological processes that do not involve apoptosis, including the control of complement-mediated cell lysis, transport of beta-amyloid precursor protein, shuttling of aberrant beta-amyloid across the blood-brain barrier, lipid scavenging, membrane remodeling, cell aggregation, and protection from immune detection and tumor necrosis factor induced cell death.
(e) Connective Tissue Growth Factor (CTGF)Connective tissue growth factor (CTGF, Swiss-Prot Accession Number P29279) is a 349-amino acid cysteine-rich polypeptide belonging to the CCN family. In vitro studies have shown that CTGF is mainly involved in extracellular matrix synthesis and fibrosis. Up-regulation of CTGF mRNA and increased CTGF levels have been observed in various diseases, including diabetic nephropathy and cardiomyopathy, fibrotic skin disorders, systemic sclerosis, biliary atresia, liver fibrosis and idiopathic pulmonary fibrosis, and nondiabetic acute and progressive glomerular and tubulointerstitial lesions of the kidney. A recent cross-sectional study found that urinary CTGF may act as a progression promoter in diabetic nephropathy.
(f) CreatinineCreatinine is a metabolite of creatine phosphate in muscle tissue, and is typically produced at a relatively constant rate by the body. Creatinine is chiefly filtered out of the blood by the kidneys, though a small amount is actively secreted by the kidneys into the urine. Creatinine levels in blood and urine may be used to estimate the creatinine clearance, which is representative of the overall glomerular filtration rate (GFR), a standard measure of renal function. Variations in creatinine concentrations in the blood and urine, as well as variations in the ratio of urea to creatinine concentration in the blood, are common diagnostic measurements used to assess renal function.
(g) Cystatin C (Cyst C)Cystatin C (Cyst C, Swiss-Prot Accession Number P01034) is a 13 kDa protein that is a potent inhibitor of the C1 family of cysteine proteases. It is the most abundant extracellular inhibitor of cysteine proteases in testis, epididymis, prostate, seminal vesicles and many other tissues. Cystatin C, which is normally expressed in vascular wall smooth muscle cells, is severely reduced in both atherosclerotic and aneurismal aortic lesions.
(h) Glutathione S-Transferase Alpha (GST-Alpha)Glutathione S-transferase alpha (GST-alpha, Swiss-Prot Accession Number P08263) belongs to a family of enzymes that utilize glutathione in reactions contributing to the transformation of a wide range of compounds, including carcinogens, therapeutic drugs, and products of oxidative stress. These enzymes play a key role in the detoxification of such substances.
(i) Kidney Injury Molecule-1 (KIM-1)Kidney injury molecule-1 (KIM-1, Swiss-Prot Accession Number Q96D42) is an immunoglobulin superfamily cell-surface protein highly upregulated on the surface of injured kidney epithelial cells. It is also known as TIM-1 (T-cell immunoglobulin mucin domain-1), as it is expressed at low levels by subpopulations of activated T-cells and hepatitis A virus cellular receptor-1 (HAVCR-1). KIM-1 is increased in expression more than any other protein in the injured kidney and is localized predominantly to the apical membrane of the surviving proximal epithelial cells.
(j) MicroalbuminAlbumin is the most abundant plasma protein in humans and other mammals. Albumin is essential for maintaining the osmotic pressure needed for proper distribution of body fluids between intravascular compartments and body tissues. Healthy, normal kidneys typically filter out albumin from the urine. The presence of albumin in the urine may indicate damage to the kidneys. Albumin in the urine may also occur in patients with long-standing diabetes, especially type 1 diabetes. The amount of albumin eliminated in the urine has been used to differentially diagnose various renal disorders. For example, nephrotic syndrome usually results in the excretion of about 3.0 to 3.5 grams of albumin in human urine every 24 hours. Microalbuminuria, in which less than 300 mg of albumin is eliminated in the urine every 24 hours, may indicate the early stages of diabetic nephropathy.
(k) Neutrophil Gelatinase-Associated Lipocalin (NGAL)Neutrophil gelatinase-associated lipocalin (NGAL, Swiss-Prot Accession Number P80188) forms a disulfide bond-linked heterodimer with MMP-9. It mediates an innate immune response to bacterial infection by sequestrating iron. Lipocalins interact with many different molecules such as cell surface receptors and proteases, and play a role in a variety of processes such as the progression of cancer and allergic reactions.
(I) Osteopontin (OPN)Osteopontin (OPN, Swiss-Prot Accession Number P10451) is a cytokine involved in enhancing production of interferon-gamma and IL-12, and inhibiting the production of IL-10. OPN is essential in the pathway that leads to type I immunity. OPN appears to form an integral part of the mineralized matrix. OPN is synthesized within the kidney and has been detected in human urine at levels that may effectively inhibit calcium oxalate crystallization. Decreased concentrations of OPN have been documented in urine from patients with renal stone disease compared with normal individuals.
(m) Tamm-Horsfall Protein (THP)Tamm-Horsfall protein (THP, Swiss-Prot Accession Number P07911), also known as uromodulin, is the most abundant protein present in the urine of healthy subjects and has been shown to decrease in individuals with kidney stones. THP is secreted by the thick ascending limb of the loop of Henley. THP is a monomeric glycoprotein of ˜85 kDa with ˜30% carbohydrate moiety that is heavily glycosylated. THP may act as a constitutive inhibitor of calcium crystallization in renal fluids.
(n) Tissue Inhibitor of Metalloproteinase-1 (TIMP-1)Tissue inhibitor of metalloproteinase-1 (TIMP-1, Swiss-Prot Accession Number P01033) is a major regulator of extracellular matrix synthesis and degradation. A certain balance of MMPs and TIMPs is essential for tumor growth and health. Fibrosis results from an imbalance of fibrogenesis and fibrolysis, highlighting the importance of the role of the inhibition of matrix degradation role in renal disease.
(o) Trefoil Factor 3 (TFF3)Trefoil factor 3 (TFF3, Swiss-Prot Accession Number Q07654), also known as intestinal trefoil factor, belongs to a small family of mucin-associated peptides that include TFF1, TFF2, and TFF3. TFF3 exists in a 60-amino acid monomeric form and a 118-amino acid dimeric form. Under normal conditions TFF3 is expressed by goblet cells of the intestine and the colon. TFF3 expression has also been observed in the human respiratory tract, in human goblet cells and in the human salivary gland. In addition, TFF3 has been detected in the human hypothalamus.
(p) Vascular Endothelial Growth Factor (VEGF)Vascular endothelial growth factor (VEGF, Swiss-Prot Accession Number P15692) is an important factor in the pathophysiology of neuronal and other tumors, most likely functioning as a potent promoter of angiogenesis. VEGF may also be involved in regulating blood-brain-barrier functions under normal and pathological conditions. VEGF secreted from the stromal cells may be responsible for the endothelial cell proliferation observed in capillary hemangioblastomas, which are typically composed of abundant microvasculature and primitive angiogenic elements represented by stromal cells.
II. Combinations of Analytes Measured by Multiplexed AssayThe method for diagnosing, monitoring, or determining kidney damage involves determining the presence or concentrations of a combination of sample analytes in a test sample. The combinations of sample analytes, as defined herein, are any group of three or more analytes selected from the biomarker analytes, including but not limited to alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF. In one embodiment, the combination of analytes may be selected to provide a group of analytes associated with a wide range of potential types of kidney damage. In another embodiment, the combination of analytes may be selected to provide a group of analytes associated with a particular type of kidney damage or region of renal injury.
In one embodiment, the combination of sample analytes may be any three of the biomarker analytes. In other embodiments, the combination of sample analytes may be any four, any five, any six, any seven, any eight, any nine, any ten, any eleven, any twelve, any thirteen, any fourteen, any fifteen, or all sixteen of the sixteen biomarker analytes. In some embodiments, the combination of sample analytes comprises alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1. In another embodiment, the combination of sample analytes may comprise a combination listed in Table A.
In one exemplary embodiment, the combination of sample analytes may include creatinine, KIM-1, and THP. In another exemplary embodiment, the combination of sample analytes may include microalbumin, creatinine, and KIM-1. In yet another exemplary embodiment, the combination of sample analytes may include creatinine, TIMP-1, and THP. In still another exemplary embodiment, the combination of sample analytes may include creatinine, microalbumin, and THP.
III. Test SampleThe method for diagnosing, monitoring, or determining a renal disorder involves determining the presence of sample analytes in a test sample. A test sample, as defined herein, is an amount of bodily fluid taken from a mammal. Non-limiting examples of bodily fluids include urine, blood, plasma, serum, saliva, semen, perspiration, tears, mucus, and tissue lysates. In an exemplary embodiment, the bodily fluid contained in the test sample is urine, plasma, or serum.
(a) MammalsA mammal, as defined herein, is any organism that is a member of the class Mammalia. Non-limiting examples of mammals appropriate for the various embodiments include humans, apes, monkeys, rats, mice, dogs, cats, pigs, and livestock including cattle and oxen. In an exemplary embodiment, the mammal is a human.
(b) Devices and Methods of Taking Bodily Fluids from Mammals
The bodily fluids of the test sample may be taken from the mammal using any known device or method so long as the analytes to be measured by the multiplexed assay are not rendered undetectable by the multiplexed assay. Non-limiting examples of devices or methods suitable for taking bodily fluid from a mammal include urine sample cups, urethral catheters, swabs, hypodermic needles, thin needle biopsies, hollow needle biopsies, punch biopsies, metabolic cages, and aspiration.
In order to adjust the expected concentrations of the sample analytes in the test sample to fall within the dynamic range of the multiplexed assay, the test sample may be diluted to reduce the concentration of the sample analytes prior to analysis. The degree of dilution may depend on a variety of factors including but not limited to the type of multiplexed assay used to measure the analytes, the reagents utilized in the multiplexed assay, and the type of bodily fluid contained in the test sample. In one embodiment, the test sample is diluted by adding a volume of diluent ranging from about ½ of the original test sample volume to about 50,000 times the original test sample volume.
In one exemplary embodiment, if the test sample is human urine and the multiplexed assay is an antibody-based capture-sandwich assay, the test sample is diluted by adding a volume of diluent that is about 100 times the original test sample volume prior to analysis. In another exemplary embodiment, if the test sample is human serum and the multiplexed assay is an antibody-based capture-sandwich assay, the test sample is diluted by adding a volume of diluent that is about 5 times the original test sample volume prior to analysis. In yet another exemplary embodiment, if the test sample is human plasma and the multiplexed assay is an antibody-based capture-sandwich assay, the test sample is diluted by adding a volume of diluent that is about 2,000 times the original test sample volume prior to analysis.
The diluent may be any fluid that does not interfere with the function of the multiplexed assay used to measure the concentration of the analytes in the test sample. Non-limiting examples of suitable diluents include deionized water, distilled water, saline solution, Ringer's solution, phosphate buffered saline solution, TRIS-buffered saline solution, standard saline citrate, and HEPES-buffered saline.
IV. Multiplexed Assay DeviceIn one embodiment, the concentration of a combination of sample analytes is measured using a multiplexed assay device capable of measuring the concentrations of up to sixteen of the biomarker analytes. A multiplexed assay device, as defined herein, is an assay capable of simultaneously determining the concentration of three or more different sample analytes using a single device and/or method. Any known method of measuring the concentration of the biomarker analytes may be used for the multiplexed assay device. Non-limiting examples of measurement methods suitable for the multiplexed assay device include electrophoresis, mass spectrometry, protein microarrays, and immunoassays including but not limited to western blot, immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA) methods, and particle-based capture-sandwich immunoassays.
(a) Multiplexed Immunoassay DeviceIn one embodiment, the concentration of a combination of sample analytes is measured using a multiplexed assay device capable of measuring the concentrations of up to 189 of the biomarker analytes. A multiplexed assay device, as defined herein, is an assay capable of simultaneously determining the concentration of three or more different sample analytes using a single device and/or method. Any known method of measuring the concentration of the biomarker analytes may be used for the multiplexed assay device. Non-limiting examples of measurement methods suitable for the multiplexed assay device include electrophoresis, mass spectrometry, protein microarrays, and immunoassays including but not limited to western blot, immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA) methods, vibrational detection using MicroElectroMagnetic Devices (MEMS), and particle-based capture-sandwich immunoassays.
(i) Capture AntibodiesIn the same embodiment, the multiplexed immunoassay device includes three or more capture antibodies. Capture antibodies, as defined herein, are antibodies in which the antigenic determinant is one of the biomarker analytes. Each of the at least three capture antibodies has a unique antigenic determinant that is one of the biomarker analytes. When contacted with the test sample, the capture antibodies form antigen-antibody complexes in which the analytes serve as antigens.
In another embodiment, the capture antibodies may be attached to a substrate in order to immobilize any analytes captured by the capture antibodies. Non-limiting examples of suitable substrates include paper or cellulose strips, polystyrene or latex microspheres, and the inner surface of the well of a microtitration tray.
(ii) IndicatorsIn one embodiment of the multiplexed immunoassay device, an indicator is attached to each of the three or more capture antibodies. The indicator, as defined herein, is any compound that registers a measurable change to indicate the presence of one of the sample analytes when bound to one of the capture antibodies. Non-limiting examples of indicators include visual indicators and electrochemical indicators.
Visual indicators, as defined herein, are compounds that register a change by reflecting a limited subset of the wavelengths of light illuminating the indicator, by fluorescing light after being illuminated, or by emitting light via chemiluminescence. The change registered by visual indicators may be in the visible light spectrum, in the infrared spectrum, or in the ultraviolet spectrum. Non-limiting examples of visual indicators suitable for the multiplexed immunoassay device include nanoparticulate gold, organic particles such as polyurethane or latex microspheres loaded with dye compounds, carbon black, fluorophores, phycoerythrin, radioactive isotopes, nanoparticles, quantum dots, and enzymes such as horseradish peroxidase or alkaline phosphatase that react with a chemical substrate to form a colored or chemiluminescent product.
Electrochemical indicators, as defined herein, are compounds that register a change by altering an electrical property. The changes registered by electrochemical indicators may be an alteration in conductivity, resistance, capacitance, current conducted in response to an applied voltage, or voltage required to achieve a desired current. Non-limiting examples of electrochemical indicators include redox species such as ascorbate (vitamin C), vitamin E, glutathione, polyphenols, catechols, quercetin, phytoestrogens, penicillin, carbazole, murranes, phenols, carbonyls, benzoates, and trace metal ions such as nickel, copper, cadmium, iron and mercury.
In this same embodiment, the test sample containing a combination of three or more sample analytes is contacted with the capture antibodies and allowed to form antigen-antibody complexes in which the sample analytes serve as the antigens. After removing any uncomplexed capture antibodies, the concentrations of the three or more analytes are determined by measuring the change registered by the indicators attached to the capture antibodies.
In one exemplary embodiment, the indicators are polyurethane or latex microspheres loaded with dye compounds and phycoerythrin.
(b) Multiplexed Sandwich Immunoassay DeviceIn another embodiment, the multiplexed immunoassay device has a sandwich assay format. In this embodiment, the multiplexed sandwich immunoassay device includes three or more capture antibodies as previously described. However, in this embodiment, each of the capture antibodies is attached to a capture agent that includes an antigenic moiety. The antigenic moiety serves as the antigenic determinant of a detection antibody, also included in the multiplexed immunoassay device of this embodiment. In addition, an indicator is attached to the detection antibody.
In this same embodiment, the test sample is contacted with the capture antibodies and allowed to form antigen-antibody complexes in which the sample analytes serve as antigens. The detection antibodies are then contacted with the test sample and allowed to form antigen-antibody complexes in which the capture agent serves as the antigen for the detection antibody. After removing any uncomplexed detection antibodies the concentration of the analytes are determined by measuring the changes registered by the indicators attached to the detection antibodies.
(c) Multiplexing ApproachesIn the various embodiments of the multiplexed immunoassay devices, the concentrations of each of the sample analytes may be determined using any approach known in the art. In one embodiment, a single indicator compound is attached to each of the three or more antibodies. In addition, each of the capture antibodies having one of the sample analytes as an antigenic determinant is physically separated into a distinct region so that the concentration of each of the sample analytes may be determined by measuring the changes registered by the indicators in each physically separate region corresponding to each of the sample analytes.
In another embodiment, each antibody having one of the sample analytes as an antigenic determinant is marked with a unique indicator. In this manner, a unique indicator is attached to each antibody having a single sample analyte as its antigenic determinant. In this embodiment, all antibodies may occupy the same physical space. The concentration of each sample analyte is determined by measuring the change registered by the unique indicator attached to the antibody having the sample analyte as an antigenic determinant.
(d) Microsphere-Based Capture-Sandwich Immunoassay DeviceIn an exemplary embodiment, the multiplexed immunoassay device is a microsphere-based capture-sandwich immunoassay device. In this embodiment, the device includes a mixture of three or more capture-antibody microspheres, in which each capture-antibody microsphere corresponds to one of the biomarker analytes. Each capture-antibody microsphere includes a plurality of capture antibodies attached to the outer surface of the microsphere. In this same embodiment, the antigenic determinant of all of the capture antibodies attached to one microsphere is the same biomarker analyte.
In this embodiment of the device, the microsphere is a small polystyrene or latex sphere that is loaded with an indicator that is a dye compound. The microsphere may be between about 3 μm and about 5 μm in diameter. Each capture-antibody microsphere corresponding to one of the biomarker analytes is loaded with the same indicator. In this manner, each capture-antibody microsphere corresponding to a biomarker analyte is uniquely color-coded.
In this same exemplary embodiment, the multiplexed immunoassay device further includes three or more biotinylated detection antibodies in which the antigenic determinant of each biotinylated detection antibody is one of the biomarker analytes. The device further includes a plurality of streptaviden proteins complexed with a reporter compound. A reporter compound, as defined herein, is an indicator selected to register a change that is distinguishable from the indicators used to mark the capture-antibody microspheres.
The concentrations of the sample analytes may be determined by contacting the test sample with a mixture of capture-antigen microspheres corresponding to each sample analyte to be measured. The sample analytes are allowed to form antigen-antibody complexes in which a sample analyte serves as an antigen and a capture antibody attached to the microsphere serves as an antibody. In this manner, the sample analytes are immobilized onto the capture-antigen microspheres. The biotinylated detection antibodies are then added to the test sample and allowed to form antigen-antibody complexes in which the analyte serves as the antigen and the biotinylated detection antibody serves as the antibody. The streptaviden-reporter complex is then added to the test sample and allowed to bind to the biotin moieties of the biotinylated detection antibodies. The antigen-capture microspheres may then be rinsed and filtered.
In this embodiment, the concentration of each analyte is determined by first measuring the change registered by the indicator compound embedded in the capture-antigen microsphere in order to identify the particular analyte. For each microsphere corresponding to one of the biomarker analytes, the quantity of analyte immobilized on the microsphere is determined by measuring the change registered by the reporter compound attached to the microsphere.
For example, the indicator embedded in the microspheres associated with one sample analyte may register an emission of orange light, and the reporter may register an emission of green light. In this example, a detector device may measure the intensity of orange light and green light separately. The measured intensity of the green light would determine the concentration of the analyte captured on the microsphere, and the intensity of the orange light would determine the specific analyte captured on the microsphere.
Any sensor device may be used to detect the changes registered by the indicators embedded in the microspheres and the changes registered by the reporter compound, so long as the sensor device is sufficiently sensitive to the changes registered by both indicator and reporter compound. Non-limiting examples of suitable sensor devices include spectrophotometers, photosensors, colorimeters, cyclic coulometry devices, and flow cytometers. In an exemplary embodiment, the sensor device is a flow cytometer.
(e) Vibrational Detection DeviceIn another exemplary embodiment, the multiplexed immunoassay device has a vibrational detection format using a MEMS. In this embodiment, the immunoassay device uses capture antibodies as previously described. However, in this embodiment, the capture antibodies are attached to a microscopic silicon microcantilever beam structure. The microcantilevers are micromechanical beams that are anchored at one end, such as diving spring boards that can be readily fabricated on silicon wafers and other materials. The microcantilever sensors are physical sensors that respond to surface stress changes due to chemical or biological processes. When fabricated with very small force constants, they can measure forces and stresses with extremely high sensitivity. The very small force constant of a cantilever allows detection not surface stress variation due to the binding of an analyte to the capture antibody on the microcantilever. Binding of the analyte results in a differential surface stress due to adsorption-induced forces, which manifests as a deflection which can be measured. The vibrational detection may be multiplexed. For more details, see Datar et al., MRS Bulletin (2009) 34:449-459 and Gaster et al., Nature Medicine (2009) 15:1327-1332, both of which are hereby incorporated by reference in their entireties.
V. Method for Diagnosing, Monitoring, or Determining a Renal DisorderIn one embodiment, a method is provided for diagnosing, monitoring, or determining a renal disorder that includes providing a test sample, determining the concentration of a combination of three or more a sample analytes, comparing the measured concentrations of the combination of sample analytes to the entries of a dataset, and identifying a particular renal disorder based on the comparison between the concentrations of the sample analytes and the minimum diagnostic concentrations contained within each entry of the dataset.
(a) Diagnostic DatasetIn an embodiment, the concentrations of the sample analytes are compared to the entries of a dataset. In this embodiment, each entry of the dataset includes a combination of three or more minimum diagnostic concentrations indicative of a particular renal disorder. A minimum diagnostic concentration, as defined herein, is the concentration of an analyte that defines the limit between the concentration range corresponding to normal, healthy renal function and the concentration reflective of a particular renal disorder. In one embodiment, each minimum diagnostic concentration is the maximum concentration of the range of analyte concentrations for a healthy, normal individual. The minimum diagnostic concentration of an analyte depends on a number of factors including but not limited to the particular analyte and the type of bodily fluid contained in the test sample. As an illustrative example, Table 1 lists the expected normal ranges of the biomarker analytes in human plasma, serum, and urine.
In one embodiment, the high values shown for each of the biomarker analytes in Table 1 for the analytic concentrations in human plasma, sera and urine are the minimum diagnostics values for the analytes in human plasma, sera, and urine, respectively. In one exemplary embodiment, the minimum diagnostic concentration in human plasma of alpha-1 microglobulin is about 16 μg/ml, beta-2 microglobulin is about 2.2 μg/ml, calbindin is greater than about 5 ng/ml, clusterin is about 134 μg/ml, CTGF is about 16 ng/ml, cystatin C is about 1170 ng/ml, GST-alpha is about 62 ng/ml, KIM-1 is about 0.57 ng/ml, NGAL is about 375 ng/ml, osteopontin is about 25 ng/ml, THP is about 0.052 μg/ml, TIMP-1 is about 131 ng/ml, TFF-3 is about 0.49 μg/ml, and VEGF is about 855 μg/ml.
In another exemplary embodiment, the minimum diagnostic concentration in human sera of alpha-1 microglobulin is about 17 μg/ml, beta-2 microglobulin is about 2.6 μg/ml, calbindin is greater than about 2.6 ng/ml, clusterin is about 152 μg/ml, CTGF is greater than about 8.2 ng/ml, cystatin C is about 1250 ng/ml, GST-alpha is about 52 ng/ml, KIM-1 is greater than about 0.35 ng/ml, NGAL is about 822 ng/ml, osteopontin is about 12 ng/ml, THP is about 0.053 μg/ml, TIMP-1 is about 246 ng/ml, TFF-3 is about 0.17 μg/ml, and VEGF is about 1630 μg/ml.
In yet another exemplary embodiment, the minimum diagnostic concentration in human urine of alpha-1 microglobulin is about 233 μg/ml, beta-2 microglobulin is greater than about 0.17 μg/ml, calbindin is about 233 ng/ml, clusterin is greater than about 0.089 μg/ml, CTGF is greater than about 0.90 ng/ml, cystatin C is about 1170 ng/ml, GST-alpha is greater than about 26 ng/ml, KIM-1 is about 0.67 ng/ml, NGAL is about 81 ng/ml, osteopontin is about 6130 ng/ml, THP is about 2.6 μg/ml, TIMP-1 is greater than about 3.9 ng/ml, TFF-3 is greater than about 21 μg/ml, and VEGF is about 517 μg/ml.
In one embodiment, the minimum diagnostic concentrations represent the maximum level of analyte concentrations falling within an expected normal range. A renal disorder may be indicated if the concentration of an analyte is higher than the minimum diagnostic concentration for the analyte.
If diminished concentrations of a particular analyte are known to be associated with a particular renal disorder, the minimum diagnostic concentration may not be an appropriate diagnostic criterion for identifying the particular renal disorder indicated by the sample analyte concentrations. In these cases, a maximum diagnostic concentration may define the limit between the expected normal concentration range for the analyte and a sample concentration reflective of a renal disorder. In those cases in which a maximum diagnostic concentration is the appropriate diagnostic criterion, sample concentrations that fall below a maximum diagnostic concentration may indicate a particular renal disorder.
A critical feature of the method of the multiplexed analyte panel is that a combination of sample analyte concentrations may be used to diagnose a renal disorder. In addition to comparing subsets of the biomarker analyte concentrations to diagnostic criteria, the analytes may be algebraically combined and compared to corresponding diagnostic criteria. In one embodiment, two or more sample analyte concentrations may be added and/or subtracted to determine a combined analyte concentration. In another embodiment, two or more sample analyte concentrations may be multiplied and/or divided to determine a combined analyte concentration. To identify a particular renal disorder, the combined analyte concentration may be compared to a diagnostic criterion in which the corresponding minimum or maximum diagnostic concentrations are combined using the same algebraic operations used to determine the combined analyte concentration.
In yet another embodiment, the analyte concentration measured from a test sample containing one type of body fluid may be algebraically combined with an analyte concentration measured from a second test sample containing a second type of body fluid to determine a combined analyte concentration. For example, the ratio of urine calbindin to plasma calbindin may be determined and compared to a corresponding minimum diagnostic urine:plasma calbindin ratio to identify a particular renal disorder.
A variety of methods known in the art may be used to define the diagnostic criteria used to identify a particular renal condition. In one embodiment, any sample concentration falling outside the expected normal range indicates a renal disorder. In another embodiment, the multiplexed analyte panel may be used to evaluate the analyte concentrations in test samples taken from a population of patients having a particular renal disorder and compared to the normal expected analyte concentration ranges. In this same embodiment, any sample analyte concentrations that are significantly higher or lower than the expected normal concentration range may be used to define a minimum or maximum diagnostic concentration, respectively. A number of studies comparing the biomarker concentration ranges of a population of patients having a renal disorder to the corresponding analyte concentrations from a population of normal healthy subjects are described in the examples section below.
In another embodiment, the sample analyte concentrations of a population of patients exposed to varying dosages of a potentially drug may be compared to each other and to the expected normal analyte concentrations. Any sample analyte concentrations falling significantly outside the expected normal analyte concentration range may be used to define diagnostic criteria. In addition, the sample analyte concentrations may be correlated to the dosage of the potentially toxic drug in order to define a diagnostic criteria used to determine the severity of a particular renal disorder based on the sample analyte concentration.
(b) Renal Disorders Associated with Minimum Diagnostic Concentrations in Diagnostic Dataset
A variety of renal disorders and locations of damage within the kidney may be identified using a comparison of the sample analyte concentrations with a set of diagnostic criteria. In one embodiment, the types of kidney damage identified by the multiplexed analyte panel include, but are not limited to glomerulonephritis, interstitial nephritis, tubular damage, vasculitis, glomerulosclerosis, and acute tubular necrosis. In another embodiment, the multiplexed analyte panel identifies secondary kidney damaged caused by exposure to agents including but not limited to therapeutic drugs, recreational drugs, medical imaging contrast agents, toxins, kidney stones, ischemia, liver transplantation, heart transplantation, lung transplantation, and hypovolemia. In yet another embodiment, the multiplexed analyte panel identifies kidney damage caused by disease including but not limited to diabetes, hypertension, autoimmune diseases including lupus, Wegener's granulomatosis, Goodpasture syndrome, primary hyperoxaluria, kidney transplant rejection, sepsis, nephritis secondary to any infection of the kidney, rhabdomyolysis, multiple myeloma, and prostate disease.
The following examples are included to demonstrate preferred embodiments of the invention.
EXAMPLESThe following examples illustrate various iterations of the invention.
Example 1 Least Detectable Dose and Lower Limit of Quantitation of Assay for Analytes Associated with Renal DisordersTo assess the least detectable doses (LDD) and lower limits of quantitation (LLOQ) of a variety of analytes associated with renal disorders, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF.
The concentrations of the analytes were measured using a capture-sandwich assay using antigen-specific antibodies. For each analyte, a range of standard sample dilutions ranging over about four orders of magnitude of analyte concentration were measured using the assay in order to obtain data used to construct a standard dose response curve. The dynamic range for each of the analytes, defined herein as the range of analyte concentrations measured to determine its dose response curve, is presented below.
To perform the assay, 5 μL of a diluted mixture of capture-antibody microspheres were mixed with 5 μL of blocker and 10 μL of pre-diluted standard sample in each of the wells of a hard-bottom microtiter plate. After incubating the hard-bottom plate for 1 hour, 10 μL of biotinylated detection antibody was added to each well, and then the hard-bottom plate was incubated for an additional hour. 10 μL of diluted streptavidin-phycoerythrin was added to each well and then the hard-bottom plate was incubated for another 60 minutes.
A filter-membrane microtiter plate was pre-wetted by adding 100 μL wash buffer, and then aspirated using a vacuum manifold device. The contents of the wells of the hard-bottom plate were then transferred to the corresponding wells of the filter-membrane plate. All wells of the hard-bottom plate were vacuum-aspirated and the contents were washed twice with 100 μL of wash buffer. After the second wash, 100 μL of wash buffer was added to each well, and then the washed microspheres were resuspended with thorough mixing. The plate was then analyzed using a Luminex 100 Analyzer (Luminex Corporation, Austin, Tex., USA). Dose response curves were constructed for each analyte by curve-fitting the median fluorescence intensity (MFI) measured from the assays of diluted standard samples containing a range of analyte concentrations.
The least detectable dose (LDD) was determined by adding three standard deviations to the average of the MFI signal measured for 20 replicate samples of blank standard solution (i.e. standard solution containing no analyte). The MFI signal was converted to an LDD concentration using the dose response curve and multiplied by a dilution factor of 2.
The lower limit of quantification (LLOQ), defined herein as the point at which the coefficient of variation (CV) for the analyte measured in the standard samples was 30%, was determined by the analysis of the measurements of increasingly diluted standard samples. For each analyte, the standard solution was diluted by 2 fold for 8 dilutions. At each stage of dilution, samples were assayed in triplicate, and the CV of the analyte concentration at each dilution was calculated and plotted as a function of analyte concentration. The LLOQ was interpolated from this plot and multiplied by a dilution factor of 2.
The LDD and LLOQ results for each analyte are summarized in Table 2:
The results of this experiment characterized the least detectible dose and the lower limit of quantification for fourteen analytes associated with various renal disorders using a capture-sandwich assay.
Example 2 Precision of Assay for Analytes Associated with Renal DisordersTo assess the precision of an assay used to measure the concentration of analytes associated with renal disorders, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF. For each analyte, three concentration levels of standard solution were measured in triplicate during three runs using the methods described in Example 1. The percent errors for each run at each concentration are presented in Table 3 for all of the analytes tested:
The results of this experiment characterized the precision of a capture-sandwich assay for fourteen analytes associated with various renal disorders over a wide range of analyte concentrations. The precision of the assay varied between about 1% and about 15% error within a given run, and between about 5% and about 15% error between different runs. The percent errors summarized in Table 2 provide information concerning random error to be expected in an assay measurement caused by variations in technicians, measuring instruments, and times of measurement.
Example 3 Linearity of Assay for Analytes Associated with Renal DisordersTo assess the linearity of an assay used to measure the concentration of analytes associated with renal disorders, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF. For each analyte, three concentration levels of standard solution were measured in triplicate during three runs using the methods described in Example 1. Linearity of the assay used to measure each analyte was determined by measuring the concentrations of standard samples that were serially-diluted throughout the assay range. The % recovery was calculated as observed vs. expected concentration based on the dose-response curve. The results of the linearity analysis are summarized in Table 4.
The results of this experiment demonstrated reasonably linear responses of the sandwich-capture assay to variations in the concentrations of the analytes in the tested samples.
Example 4 Spike Recovery of Analytes Associated with Renal DisordersTo assess the recovery of analytes spiked into urine, serum, and plasma samples by an assay used to measure the concentration of analytes associated with renal disorders, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF. For each analyte, three concentration levels of standard solution were spiked into known urine, serum, and plasma samples. Prior to analysis, all urine samples were diluted 1:2000 (sample: diluent), all plasma samples were diluted 1:5 (sample: diluent), and all serum samples were diluted 1:2000 (sample: diluent).
The concentrations of the analytes in the samples were measured using the methods described in Example 1. The average % recovery was calculated as the proportion of the measurement of analyte spiked into the urine, serum, or plasma sample (observed) to the measurement of analyte spiked into the standard solution (expected). The results of the spike recovery analysis are summarized in Table 5.
The results of this experiment demonstrated that the sandwich-type assay is reasonably sensitive to the presence of all analytes measured, whether the analytes were measured in standard samples, urine samples, plasma samples, or serum samples.
Example 5 Matrix Interferences of Analytes Associated with Renal DisordersTo assess the matrix interference of hemoglobin, bilirubin, and triglycerides spiked into standard samples, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF. For each analyte, three concentration levels of standard solution were spiked into known urine, serum, and plasma samples. Matrix interference was assessed by spiking hemoglobin, bilirubin, and triglyceride into standard analyte samples and measuring analyte concentrations using the methods described in Example 1. A % recovery was determined by calculating the ratio of the analyte concentration measured from the spiked sample (observed) divided by the analyte concentration measured form the standard sample (expected). The results of the matrix interference analysis are summarized in Table 6.
The results of this experiment demonstrated that hemoglobin, bilirubin, and triglycerides, three common compounds found in urine, plasma, and serum samples, did not significantly degrade the ability of the sandwich-capture assay to detect any of the analytes tested.
Example 6 Sample Stability of Analytes Associated with Renal DisordersTo assess the ability of analytes spiked into urine, serum, and plasma samples to tolerate freeze-thaw cycles, the following experiment was conducted. The analytes measured were alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF. Each analyte was spiked into known urine, serum, and plasma samples at a known analyte concentration. The concentrations of the analytes in the samples were measured using the methods described in Example 1 after the initial addition of the analyte, and after one, two and three cycles of freezing and thawing. In addition, analyte concentrations in urine, serum and plasma samples were measured immediately after the addition of the analyte to the samples as well as after storage at room temperature for two hours and four hours, and after storage at 4° C. for 2 hours, four hours, and 24 hours.
The results of the freeze-thaw stability analysis are summarized in Table 7. The % recovery of each analyte was calculated as a percentage of the analyte measured in the sample prior to any freeze-thaw cycles.
The results of the short-term stability assessment are summarized in Table 8. The % recovery of each analyte was calculated as a percentage of the analyte measured in the sample prior to any short-term storage.
The results of this experiment demonstrated that the analytes associated with renal disorders tested were suitably stable over several freeze/thaw cycles, and up to 24 hrs. of storage at a temperature of 4° C.
Example 8 Diagnosis of Renal Damage Using Detection of Analytes in Human Urine SamplesTo assess the effectiveness of a human kidney toxicity panel to detect renal damage due to disease states, the following experiment was conducted. Urine samples were obtained from healthy control patients (n=5), renal cancer patients (n=4) and “other” cancer patients (n=8) afflicted with lung cancer, pancreatic cancer, liver cancer, or colon cancer. All urine samples were diluted as described in Example 4 and subjected to a sandwich-capture assay as described in Example 1. Urine concentrations of analytes included in a human kidney toxicity panel were measured by the assay, including alpha-1 microglobulin (A1M), beta-2 microglobulin (B2M), calbindin, clusterin, CTGF, cystatin C, GST-alpha, KIM-1, NGAL, osteopontin (OPN), THP, TIMP-1, TFF-3, and VEGF.
The results of this experiment demonstrated that panels of analytes detected in urine samples were capable of identifying patients having renal damage resulting from renal cancer and other cancers.
Example 9 Analysis of Kidney Biomarkers in Plasma and Urine from Patients with Renal InjuryA screen for potential protein biomarkers in relation to kidney toxicity/damage was performed using a panel of biomarkers, in a set of urine and plasma samples from patients with documented renal damage. The investigated patient groups included diabetic nephropathy (DN), obstructive uropathy (OU), analgesic abuse (AA) and glomerulonephritis (GN) along with age, gender and BMI matched control groups. Multiplexed immunoassays were applied in order to quantify the following protein analytes: Alpha-1 Microglobulin (α1M), KIM-1, Microalbumin, Beta-2-Microglobulin (β2M), Calbindin, Clusterin, CystatinC, TreFoilFactor-3 (TFF-3), CTGF, GST-alpha, VEGF, Calbindin, Osteopontin, Tamm-HorsfallProtein (THP), TIMP-1 and NGAL.
Li-Heparin plasma and mid-stream spot urine samples were collected from four different patient groups. Samples were also collected from age, gender and BMI matched control subjects. 20 subjects were included in each group resulting in a total number of 160 urine and plasma samples. All samples were stored at −80° C. before use. Glomerular filtration rate for all samples was estimated using two different estimations (Modification of Diet in Renal Disease or MDRD, and the Chronic Kidney Disease Epidemiology Collaboration or CKD-EPI) to outline the eGFR (estimated glomerular filtration rate) distribution within each patient group (
The majority of the measured proteins showed a correlation to eGFR. Measured variables were correlated to eGFR using Pearson's correlations coefficient, and samples from healthy controls and all disease groups were included in the analysis. 11 and 7 proteins displayed P-values below 0.05 for plasma and urine (Table 9) respectively.
For the various disease groups, univariate statistical analysis revealed that in a direct comparison (T-test) between cases and controls, a number of proteins were differentially expressed in both urine and plasma (Table 10 and
Application of multivariate analysis yielded statistical models that predicted disease from control samples (plasma results are shown in
In conclusion, these results form a valuable base for further studies on these biomarkers in urine and plasma both regarding baseline levels in normal populations and regarding the differential expression of the analytes in various disease groups. Using this panel of analytes, error rates from adaboosting and/or random forest were low enough (<10%) to allow a prediction model to differentiate between control and disease patient samples. Several of the analytes showed a greater correlation to eGFR in plasma than in urine.
Example 10 Statistical Analysis of Kidney Biomarkers in Plasma and Urine from Patients with Renal InjuryUrine and plasma samples were taken from 80 normal control group subjects and 20 subjects from each of four disorders: analgesic abuse, diabetic nephropathy, glomerulonephritis, and obstructive uropathy. The samples were analyzed for the quantity and presence of 16 different proteins (alpha-1 microglobulin (α1M), beta-2 microglobulin (β2M), calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF) as described in Example 1 above. The goal was to determine the analytes that distinguish between a normal sample and a diseased sample, a normal sample and an obstructive uropathy (OU) sample, and finally, an glomerulonephritis sample from the other disease samples (diabetic nephropathy (DN), analgesic abuse (AA), and glomerulonephritis (GN)).
From the above protein analysis data, bootstrap analysis was used to estimate the future performance of several classification algorithms. For each bootstrap run, training data and testing data was randomly generated. Then, the following algorithms were applied on the training data to generate models and then apply the models to the testing data to make predictions: automated Matthew's classification algorithm, classification and regression tree (CART), conditional inference tree, bagging, random forest, boosting, logistic regression, SVM, and Lasso. The accuracy rate and ROC areas were recorded for each method on the prediction of the testing data. The above was repeated 100 times. The mean and the standard deviation of the accuracy rates and of the ROC areas were calculated.
The mean error rates and AUROC were calculated from urine and AUROC was calculated from plasma for 100 runs of the above method for each of the following comparisons: disease (AA+GN+OU+DN) vs. normal (
The average relative importance of 16 different analytes (alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, and VEGF) and 4 different clinical variables (weight, BMI, age, and gender) from 100 runs were analyzed with two different statistical methods—random forest (plasma and urine samples) and boosting (urine samples)—for each of the following comparisons: disease (AA+GN+OU+DN) vs. normal (
According to one aspect, sample input device 1502 is a computer or processing device 1508, such as a personal computer, a server computer, or a mobile processing device. The computer 1508 may include a display such as a computer monitor, for viewing data, and an input device, such as a keyboard or a pointing device (e.g., a mouse, trackball, pen, touch pad, or other device), for entering data. The computer 1508 is used by a user to enter analyte concentrations of a test sample for processing by the RDSS 1504. For example, the user uses the keyboard to interact with an analyte concentration entry form (not shown) on the display to enter test sample analyte data that includes, for example, three or more analyte concentrations.
In another embodiment, the test sample analyte concentrations are collected and then transmitted to the RDSS 1504 via an analyte measurement/sensor device 1510 (e.g., multiplexed immunoassay device) that measures the sample analyte concentration. The analyte measurement/sensor device 1510 communicates the measured sample analyte concentrations data to the RDSS 1504 via a data cable, infrared signal, wireless connection, or other methods of data transmission known in the art.
The RDDS 1504 executes a renal disorder determining application 1512 in response to test sample analyte concentration data received from the received from the sample input device 102. The renal disorder determining application (RDDA) 1512 analyzes the analyte concentration data for the test sample and determines whether the received analyte concentration data is indicative of renal disorder and, if so, a type of renal disorder. The renal disorder determining application 1512 then displays whether the result of the analysis is positive or negative for a renal disorder and, if applicable, the type of renal disorder.
According to one aspect, the RDDS 1904 retrieves concentration threshold data and/or disorder threshold data from the data source 1506 to determine whether the received analyte concentration data is indicative of one or more renal disorders. The data source 1506 is, for example, a computer system, a database, or another data system that stores data, electronic documents, records, other documents, and/or other data. The data source 1506 may include memory and one or more processors or processing systems to receive, process, and transmit communications and store and retrieve data.
According to one aspect, the data source 1506 includes a diagnostic analytic concentrations database 1514 that stores normal ranges of biomarker analytes for human plasma, serum, and urine, such described above in connection with Table 1. The entries of the diagnostic analytic concentrations database 1514 may also include additional minimum diagnostic concentrations to further define diagnostic criteria including but not limited to minimum diagnostic concentrations for additional types of bodily fluids, additional types of mammals, and severities of a particular disorder. As described above, if the measured concentration for a particular analyte of a sample of plasma exceeds the high value in Table 1, then the measured concentration of that particular may be indicative of a renal disorder or disease in the subject from with the test sample was collected.
According to one aspect, the disorder database 1516 includes various data tables index by disorder or disease type. Each data table corresponds to a specific disorder/disease type and identifies a list of minimum diagnostic concentrations that are indicative of that particular disease. For example, diabetic nephropathy data table indicates by sample type (i.e., plasma, urine, serum) the minimum concentration required, if any, for each of sixteen analyte biomarkers described above in connection with Table 1.
Although, the data source is illustrated in
The RDDA 1512 includes instructions or modules that are executable by the processing system 1602 to manage the retrieval of renal disorder diagnostic data, including a record, from the data source 1506. The RDDS 1504 includes computer readable media 1604 configured with the RDDA 1512.
Computer readable medium (CRM) 1604 may include volatile media, nonvolatile media, removable media, non-removable media, and/or another available medium that can be accessed by the RDDS 1504. By way of example and not limitation, computer readable medium 1604 comprises computer storage media and communication media. Computer storage media includes memory, volatile media, nonvolatile media, removable media, and/or non-removable media implemented in a method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. Communication media may embody computer readable instructions, data structures, program modules, or other data and include an information delivery media or system.
An analyte input module 1606 receives three or more sample analyte concentrations that include the biomarker analytes. In one embodiment, the sample analyte concentrations are entered as input by a user of the computer 1508. In another embodiment, the sample analyte concentrations are received directly from analyte measure/sensor device 1510, such as a multiplexed immunoassay device.
In another embodiment, the analyte input module 1606 receives sample analyte concentrations for at least six biomarker analytes. In one example, the at least six biomarker analytes include alpha 1 microglobulin, cystatin C, KIM-1, Tamm-Horsfall, Beta 2-microglobulin, and TIMP-1.
In another embodiment, the analyte input module 1606 receives sample analyte concentrations for sixteen biomarker analytes. In one example, the sixteen biomarker analytes include the analyte types shown in Table 1.
A comparison module 1608 compares each analyte concentration of a sample received from the analyte input module 1606 to a corresponding analyte entry in the diagnostic analyte database to determine if one or more concentrations for a particular analyte of the sample are exceed the minimum diagnostic value for that particular analyte. For example, referring briefly to Table 1, if the sample concentrations are obtained from plasma and the particular analyte is calbindin, the comparison module compares the measured calbindin analyte concentration to the sample to the corresponding high concentration value for plasma to determine if it is greater than about 5 ng/ml. A measured calbindin analyte concentration less than about 5 ng/ml indicates is not indicative of renal disorder. In contrast, a measured calbindin analyte concentration that is greater than about 5 ng/ml is indicative of a renal disorder.
An analysis module 1610 determines a most likely renal disorder as a function of the particular measured analyte concentrations identified as indicative of a renal disorder by the comparison module. For example, the analysis module 1610 compares the particular measured analyte concentrations to entries in the disorder tables stored in the renal disorder database 1516 to identify the most likely type renal disorder. Each disorder table includes, for example, the minimum concentrations or threshold concentrations for each of the sixteen analytes types shown in Table 1 that are associated with the diagnosis of a particular renal disorder or disease. It is also contemplated that the analyte types listed in a disorder table for particular renal disorder or disease may be different from the analyte types listed in another disorder table for a different renal disorder or disease.
In one embodiment, the most likely renal disorder is the particular renal disorder type in the disorder database 1516 having the most minimum diagnostic concentrations that are less than the corresponding sample analyte concentrations. In other words, the most likely disorder is identified from the disorder table that includes the most threshold concentrations that are exceeded by the sample analyte concentrations. For example, consider that five of the sample analyte concentrations exceed the minimum threshold concentrations for corresponding analytes in the disorder table for a first renal disorder, such as analgesic abuse. Also, consider that four of the sample analyte concentrations exceed the minimum threshold concentrations for corresponding analytes in a disorder table for a second renal disorder, such as obstructive uropathy. In this example, the most likely renal disorder is analgesic abuse.
In one embodiment, the most likely renal disorder is the particular renal disorder type in the disorder database 1516 having the most minimum diagnostic concentrations that are less than the corresponding sample analyte concentrations. In other words, the most likely disorder is identified from the disorder table that includes the most threshold concentrations that are exceeded by the sample analyte concentrations. For example, consider that five of the sample analyte concentrations exceed the minimum threshold concentrations for corresponding analytes in a disorder table for a first renal disorder, such as analgesic abuse. Also, consider that four of the sample analyte concentrations exceed the minimum threshold concentrations for corresponding analytes in a disorder table for a second renal disorder, such as obstructive uropathy. In this example, the most likely renal disorder is analgesic abuse.
In another embodiment, the most likely renal disorder is the particular renal disorder from the database entry having minimum diagnostic concentrations that are all less than the corresponding sample analyte concentrations.
In yet other embodiments, the analysis module 1610 combines the sample analyte concentrations algebraically to calculate a combined sample analyte concentration that is compared to a combined minimum diagnostic concentration calculated from the corresponding minimum diagnostic criteria using the same algebraic operations. See Table A for example combinations. Other combinations of sample analyte concentrations from within the same test sample, or combinations of sample analyte concentrations from two or more different test samples containing two or more different bodily fluids may be used to determine a particular renal disorder in still other embodiments.
An output module 1612 generates a display of analyte types and corresponding concentrations for each of the measured analytes identified as indicative of a renal disorder by the comparison module. The output module 1612 also generates a display of the most likely renal disorder determined by the analysis module 1610.
If one or more of the analyte concentrations for the sample are determined to be greater than the corresponding threshold analyte concentrations at 1708, the one or more analyte concentrations are then compared to disorder threshold analyte concentrations in a disorder database at 1712. The disorder threshold analyte concentrations correspond to minimum analyte concentrations associated with a particular renal disorder or disease. At 1714, the particular disorder that corresponds to the disorder table that has the most disorder threshold analyte concentrations exceeded by the sample analyte concentrations is identified as the most likely renal disorder. The one or more of the analyte concentrations for the sample and the most likely renal disorder type is generated for display via the computer at 1716.
It should be appreciated by those of skill in the art that the techniques disclosed in the examples above represent techniques discovered by the inventors to function well in the practice of the invention. Those of skill in the art should, however, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention, therefore all matter set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.
Claims
1. A diagnostic system for determining a renal disorder in a mammal from an assay comprising at least three analyte biomarkers collected from a sample of a body fluid of the mammal, the diagnostic system comprising:
- a data source comprising a first threshold concentration for each of the at least three biomarker analytes and a second threshold concentration for each of the at least three biomarker analytes for each of a plurality of disorders;
- a renal disorder determining application comprising modules executable by a processor to determine the renal disorder, the renal disorder determining application comprising: an analyte input module to receive analyte concentrations data for the sample from an input device, the analyte concentrations data comprising analyte concentrations for each of the at least three biomarker analytes; a comparison module to: compare each analyte concentration of the sample to a corresponding first threshold concentration; and identify one or more analyte concentrations of the sample that exceed the corresponding first threshold concentration; an analysis module to: compare each of the one or more analyte concentrations of the sample identified by the comparison module to a corresponding second threshold concentration associated with each of the at least three biomarker analytes for each of the plurality of disorders; determine a number of corresponding second threshold concentrations exceeded by the one or more analyte concentrations of the sample for each of the plurality of disorders; and identify a particular one of the plurality of disorders having a maximum number of corresponding second threshold concentrations that are exceeded by the one or more analyte concentrations of the sample as the most likely renal disorder; and an output module to generate the one or more analyte concentrations and the particular one of the plurality of disorders for display.
2. The system of claim 1 wherein the data source comprises:
- a diagnostic analytic concentrations database to store each of the first threshold concentrations; and
- a disorder database to store a plurality of tables, each of the plurality tables comprising the second threshold concentration data for each of the at least three biomarker analytes and corresponding to one of the plurality of disorders
3. The system of claim 2 wherein the plurality of disorders comprises at least one member from a group consisting of glomerulonephritis, interstitial nephritis, tubular damage, vasculitis, glomerulosclerosis, acute renal failure, chronic renal failure, nephrosis, nephropathy, polycystic kidney disease, Bright's disease, renal transplant, chronic unilateral obstructive uropathy, chronic bilateral obstructive uropathy, acute unilateral obstructive uropathy, acute bilateral obstructive uropathy, renal damage secondary to a disease state including diabetes, hypertension, autoimmune diseases including lupus, Wegener's granulomatosis, and Goodpasture syndrome, primary hyperoxaluria, kidney transplant rejection, sepsis, nephritis secondary to infection of the kidney, rhabdomyolysis, multiple myeloma, and prostate diseases, and renal damage caused by exposure to secondary agents and conditions including therapeutic drugs, recreational drugs, contrast agents, toxins, nephrolithiasis, ischemia, liver transplantation, heart transplantation, lung transplantation, and hypovolemia.
4. The system of claim 1 wherein input device comprises a multiplexed immunoassay device.
5. The system of claim 4 wherein the multiplexed immunoassay device comprises at least one member of another group consisting of a multiplexed sandwich immunoassay device, a microsphere-based capture-sandwich immunoassay device, and a vibrational detection-based immunoassay device.
6. The system of claim 1 wherein input device comprises a computer.
7. The system of claim 1 wherein first threshold concentration corresponds to a maximum concentration of an analyte concentration range associated with a normal renal function.
8. The system of claim 1 wherein:
- the data source further comprises a combination threshold concentration for each of a plurality of combinations of concentration of the sixteen biomarker analytes associated with each of the plurality of disorders; and
- the analysis module is further configured to: assign a weight to each of the one or more analyte concentrations identified by the comparison module; calculate a combined sample analyte concentration based on the weight assigned to each analyte concentration; and compare a corresponding combination threshold concentration to the combined sample analyte concentration to identify the particular renal disorder.
9. The system of claim 1 wherein the assay comprises at least six analyte biomarkers collected from the sample, the at least six analytes comprising alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1.
10. The system of claim 1 wherein the assay comprises at least sixteen analyte biomarkers collected from the sample, the at least sixteen analytes comprising alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, and cortisol.
11. A diagnostic system for determining a renal disorder in a mammal from an assay comprising at least three analyte biomarkers collected from a sample of a body fluid of the mammal, the diagnostic system comprising:
- a renal disorder determining application comprising modules executable by a processor to determine the renal disorder, the renal disorder determining application comprising: an analyte input module to receive analyte concentrations data for the sample from an input device, the analyte concentrations data comprising analyte concentrations for each of the at least three analyte biomarkers; a comparison module to: compare each analyte concentration of the sample to a corresponding threshold concentration retrieved from an analyte concentration database; and identify one or more analyte concentrations of the sample that exceed the corresponding first threshold concentration; an analysis module to: retrieve a combination threshold concentration for each of a plurality of combinations of concentrations of the at least three analyte biomarkers associated with each of a plurality of disorders; and assign a weight to each of the one or more analyte concentrations of the sample identified by the comparison module; calculate a combined sample analyte concentration based on the weight assigned to each analyte concentration; and compare a corresponding combination threshold concentration to the combined sample analyte concentration to identify the renal disorder; and an output module to generate the one or more analyte concentrations and the renal disorder for display.
12. The system of claim 11, wherein the combined sample analyte concentration and the corresponding combination threshold concentration correspond to a combination of a same grouping of three analyte types.
13. The system of claim 11 wherein the assay comprises at least six analyte biomarkers collected from the sample, the at least six analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1.
14. The system of claim 11 wherein the assay comprises at least sixteen analyte biomarkers collected from the sample, the at least sixteen analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, and cortisol.
15. The system of claim 11 wherein input device comprises a multiplexed immunoassay device, and wherein the multiplexed immunoassay device comprises at least one member of another group consisting of a multiplexed sandwich immunoassay device, a microsphere-based capture-sandwich immunoassay device, and a vibrational detection-based immunoassay device.
16. A computer-readable medium encoded with a renal disorder determining application comprising modules executable by a processor to determine a renal disorder from an assay comprising at least three biomarker analytes collected from a sample of a body fluid of a mammal, the renal disorder determining application comprising:
- an analyte input module to receive analyte concentrations data for the sample from an input device, the analyte concentrations data comprising analyte concentrations for each of the at least three biomarker analytes;
- a comparison module to: compare each analyte concentration of the sample to a corresponding first threshold concentration retrieved from a data source; and identify one or more analyte concentrations of the sample that exceed the corresponding first threshold concentration;
- an analysis module to: compare each of the one or more analyte concentrations of the sample identified by the comparison module to a corresponding second threshold concentration retrieved from the data source, the corresponding second threshold concentration associated with each of the at least three biomarker analytes for each of a plurality of disorders; determine a number of corresponding second threshold concentrations exceeded by the one or more analyte concentrations of the sample for each of the plurality of disorders; and identify a particular one of the plurality of disorders having a maximum number of corresponding second threshold concentrations that are exceeded by the one or more analyte concentrations of the sample as the most likely renal disorder; and
- an output module to generate the one or more analyte concentrations and the particular one of the plurality of disorders for display.
17. The computer-readable medium of claim 16 wherein the data source comprises:
- a diagnostic analytic concentrations database to store each of the first threshold concentrations; and
- a disorder database to store a plurality of tables, each of the plurality tables comprising the second threshold concentration data for each of the sixteen biomarker analytes and corresponding to one of the plurality of disorders
18. The computer-readable medium of claim 16 wherein the plurality of disorders is selected from a group consisting of glomerulonephritis, interstitial nephritis, tubular damage, vasculitis, glomerulosclerosis, acute renal failure, chronic renal failure, nephrosis, nephropathy, polycystic kidney disease, Bright's disease, renal transplant, chronic unilateral obstructive uropathy, chronic bilateral obstructive uropathy, acute unilateral obstructive uropathy, acute bilateral obstructive uropathy, renal damage secondary to a disease state including diabetes, hypertension, autoimmune diseases including lupus, Wegener's granulomatosis, and Goodpasture syndrome, primary hyperoxaluria, kidney transplant rejection, sepsis, nephritis secondary to infection of the kidney, rhabdomyolysis, multiple myeloma, and prostate diseases, and renal damage caused by exposure to secondary agents and conditions including therapeutic drugs, recreational drugs, contrast agents, toxins, nephrolithiasis, ischemia, liver transplantation, heart transplantation, lung transplantation, and hypovolemia.
19. The computer-readable medium of claim 16 wherein first threshold concentration corresponds to a maximum concentration of an analyte concentration range associated with a normal renal function.
20. The computer-readable medium of claim 16 wherein:
- the data source further comprises a combination threshold concentration for each of a plurality of combinations of concentration of the at least three biomarker analytes associated with each of the plurality of disorders; and
- the analysis module is further configured to: assign a weight to each of the one or more analyte concentrations identified by the comparison module; calculate a combined sample analyte concentration based on the weight assigned to each analyte concentration; and
- compare a corresponding combination threshold concentration to the combined sample analyte concentration to identify the renal disorder to display.
21. The computer-readable medium of claim 20, wherein the combined sample analyte concentration and the corresponding combination threshold concentration correspond to a combination of a same grouping of three analyte types.
22. The system of claim 16 wherein the assay comprises at least six analyte biomarkers collected from the sample, the at least six analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1.
23. The system of claim 16 wherein the assay comprises at least sixteen analyte biomarkers collected from the sample, the at least sixteen analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, and cortisol.
24. A method for determining a renal disorder in a mammal, the method comprising:
- receiving analyte concentrations data for a sample a body fluid of the mammal from an input device, the analyte concentrations data comprising analyte concentrations for each of at least three analyte biomarkers;
- processing the analyte concentrations data at a processor, the processing comprising: comparing each analyte concentration of the sample to a corresponding first threshold concentration retrieved from a data source; identifying one or more analyte concentrations of the sample that exceed the corresponding first threshold concentration; comparing each of the one or more analyte concentrations of the sample identified by the comparison module to a corresponding second threshold concentration retrieved from the data source, the corresponding second threshold concentration associated with each of the at least three analyte biomarkers for each of the plurality of disorders; determining a number of corresponding second threshold concentrations exceeded by the one or more analyte concentrations of the sample for each of the plurality of disorders; and identifying a particular one of the plurality of disorders having a maximum number of corresponding second threshold concentrations that are exceeded by the one or more analyte concentrations of the sample as the most likely renal disorder; and
- generating the one or more analyte concentrations and the particular one of the plurality of disorders for display.
25. The method of claim 24 further comprising:
- retrieving, at the processor, a combination threshold concentration for each of a plurality of combinations of concentration of the sixteen biomarker analytes associated with each of a plurality of disorders; and
- assigning a weight to each of the one or more analyte concentrations identified by the comparison module;
- calculating a combined sample analyte concentration based on the weight assigned to each analyte concentration; and
- comparing a corresponding combination threshold concentration to the combined sample analyte concentration to identify the renal disorder to display.
26. The method of claim 25 wherein the combined sample analyte concentration and the corresponding combination threshold concentration correspond to a combination of a same three analyte types.
27. The method of claim 24 wherein the analyte concentrations data comprises analyte concentrations for each of at least six analyte biomarkers, the at least six analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1.
28. The method of claim 24 wherein the analyte concentrations data comprises analyte concentrations for each of at least sixteen analyte biomarkers, the at least sixteen analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, and cortisol.
29. A method for determining a renal disorder in a mammal, the method comprising:
- receiving analyte concentrations data for a sample a body fluid of the mammal from an input device, the analyte concentrations data comprising analyte concentrations for each of at least three analyte biomarkers;
- processing the analyte concentrations data at a processor, the processing comprising: comparing each analyte concentration of the sample to a corresponding threshold concentration retrieved from an analyte concentration database; and identifying one or more analyte concentrations of the sample that exceed the corresponding first threshold concentration; retrieving a combination threshold concentration for each of a plurality of combinations of concentrations of the plurality of biomarker analytes associated with each of a plurality of disorders; and assigning a weight to each of the one or more analyte concentrations of the sample identified by the comparison module; calculating a combined sample analyte concentration based on the weight assigned to each analyte concentration; and comparing a corresponding combination threshold concentration to the combined sample analyte concentration to identify the renal disorder; and generating the one or more analyte concentrations and the renal disorder for display.
30. The method of claim 29 wherein the combined sample analyte concentration and the corresponding combination threshold concentration correspond to a combination of a same grouping of analyte types.
31. The method of claim 29 wherein the analyte concentrations data comprises analyte concentrations for each of at least six analyte biomarkers, the at least six analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, cystatin C, KIM-1, THP, and TIMP-1.
32. The method of claim 29 wherein the analyte concentrations data comprises analyte concentrations for each of at least sixteen analyte biomarkers, the at least sixteen analyte biomarkers comprising alpha-1 microglobulin, beta-2 microglobulin, calbindin, clusterin, CTGF, creatinine, cystatin C, GST-alpha, KIM-1, microalbumin, NGAL, osteopontin, THP, TIMP-1, TFF-3, VEGF, BLC, CD40, IGF BP2, MMP3, peptide YY, stem cell factor, TNF RII, AXL, Eotaxin 3, FABP, FGF basic, myoglobin, resistin, TRAIL R3, endothelin 1, NrCAM, Tenascin C, VCAM1, and cortisol.
Type: Application
Filed: Aug 6, 2010
Publication Date: Mar 17, 2011
Applicant: Rules-Based Medicine, Inc. (Austin, TX)
Inventors: Samuel T. Labrie (Austin, TX), James P. Mapes (Lakeway, TX), Ralph L. McDade (Austin, TX), Dominic Eisinger (Keene, NY), Karri L. Ballard (Austin, TX), Michael D. Spain (Austin, TX)
Application Number: 12/852,202
International Classification: C40B 30/02 (20060101); C40B 60/12 (20060101); C40B 40/00 (20060101);
