Abstract: The present invention provides a method of detecting platelet activation in a patient, the method comprising the steps of a) obtaining a blood sample from a patient suspected of having heparin-induced thrombocytopenia (HIT); b) incubating an effective amount of platelet factor 4 (PF4) with a sample of platelets to yield a sample of PF4-treated platelets; c) contacting the patient blood sample with the PF4-treated platelets; and d) measuring the extent of platelet activation, wherein an increase in platelet activation compared with results obtained using a normal blood sample is indicative of the patient having HIT.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having at least two of a G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having a combination of G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having at least two of a G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having at least two of a G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having at least two of a G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: Methods and kits for measuring levels of von Willebrand factor function in a sample without using a platelet aggregation agonist, such as ristocetin, comprising recombinant glycoprotein Ib? having at least two of a G233V, D235Y and M239V mutations and an agent to detect a complex between the recombinant glycoprotein Ib? and von Willebrand factor.

Abstract: A protein preparation that mediates Ca+2 transbilayer movement of phospholipid is disclosed. Additionally, a modified or mutated protein preparation, wherein the protein has a reduced ability to mediate transbilayer movement, is disclosed. In a preferred form of the invention, the protein has been modified such that post-translational modification can no longer occur.

Abstract: A method for genetic typing includes the steps of amplifying a genetic sequence of a subject to obtain amplified DNA, which genetic sequence occurs naturally in two or more genetic types, bringing a sample of the amplified DNA into contact with an oligonucleotide probe bound to a support under stringent hybridizing conditions, which oligonucleotide probe hybridizes specifically with DNA having a sequence of one of the genetic types and not with DNA having a sequence of the other genetic types, removing unbound amplified DNA, for example, by washing the support, and analyzing the sample to determine if the one genetic type associated with the probe is present. Use of a solid support such as microbeads provides a more rapid method for identifying polymorphic nucleotide sequences of polymorphic genes, such an HLA sequences.

Abstract: A protein preparation that mediates Ca+2 transbilayer movement of phospholipid is disclosed. Additionally, a modified or mutated protein preparation, wherein the protein has a reduced ability to mediate transbilayer movement, is disclosed. In a preferred form of the invention, the protein has been modified such that post-translational modification can no longer occur.

Abstract: A method for HLA typing by amplification of a sample followed by sequence-specific oligonucleotide hybridization with a labelled oligonucleotide probe provides for both positive and negative controls. Control sequences representing known allelic polymorphisms at the locus in question are subjected to the labelled probe along with the sample. This method reduces errors and improves the chance of obtaining a successful tissue match, as is vital in the case of tissue transplants, particularly bone marrow transplants. Probes and PCR primers useful in HLA-DR typing are also provided.

Abstract: An protein preparation that mediates Ca+2 transbilayer movement of phospholipid is disclosed. A recombinantly engineered DNA sequence encoding the protein, an inhibitor of the protein activity, genetically engineered cells with altered protein activity, and therapeutic methods are also disclosed.

Abstract: A glycoprotein, PECAM-1, and variants thereof can be obtained by expression in a transformed host cell of a polynucleotide coding for the glycoprotein or a variant polypeptide. PECAM-1 can also be isolated from cellular sources. An antibody specific for PECAM-1 or a PECAM variant can be produced via recombinant techniques, or can be obtained from a hybridoma.

Abstract: A method of detecting heparin-induced antibodies to complete a diagnosis of heparin-induced thrombocytopenia (HITP) is disclosed. This method comprises the first step of attaching a glycosaminoglycan to a solid support, wherein the glycosaminoglycan is attached to the solid support only at the reducing end of the molecule (unidirectionally). Platelet factor 4 is then bound to the glycosaminoglycan forming a complex having an epitope recognizable by antibodies generated in an HITP immune response. Human blood plasma or serum from a patient suspected of having HITP is exposed to the complex and the complex is analyzed to determine if HITP-related antibodies are present. A device and kit used in performing the diagnostic assay are also disclosed.

Abstract: Isolated polynucleotide molecules and peptides encoded by these molecules can be used in the analysis of alloantigen phenotypes, as well as in diagnostic and therapeutic applications, relating to human platelet Pen polymorphism. By analyzing genomic DNA or amplified genomic DNA, or amplified cDNA derived from platelet mRNA, it is possible to type glycoprotein GPIIIa with regard to the Pen polymorphism, for example, in the context of diagnosing and treating clinical syndromes associated with GPIIIa-related immune responses.

Abstract: A method of detecting heparin-induced antibodies to complete a diagnosis of heparin-induced thrombocytopenia HITP is disclosed. In one embodiment, this method comprises binding human platelet factor 4 to a linear, non-glycosaminoglycan polymer carrying negative charges distributed along the polymer chain, wherein the negative charge carried by the polymer is less than 10 .ANG. from the polymer chain. In another embodiment, the negative charge is a strong negative charge. A complex having one or more epitopes recognizable by antibodies generated in a HITP immune response is formed. One then contacts blood plasma or serum from a human patient suspected of having HITP with the complex and analyzes the complex to determine if the HITP-related antibodies are present. In another embodiment of the invention, a kit for diagnosing HITP is disclosed.

Abstract: A glycoprotein, PECAM-1, and variants thereof can be obtained by expression in a transformed host cell of a polynucleotide coding for the glycoprotein or a variant polypeptide. PECAM-1 can also be isolated from cellular sources. An antibody specific for PECAM-1 or a PECAM variant can be produced via recombinant techniques, or can be obtained from a hybridoma.

Abstract: An approach to monitoring immune responses relies on determining the range of sizes of amplified DNAs which code for the CDR3 regions of Ig or TcR molecules of one or more classes or families. Typically the relative quantity of DNAs corresponding to different CDR3 regions of the Ig or TcR molecules of a class is also determined. The progress of an immune response is followed by making these determinations at different times.

Abstract: Isolated polynucleotide molecules and peptides encoded by these molecules can be used in the analysis of alloantigen phenotypes, as well as in diagnostic and therapeutic applications, relating to human platelet Pen polymorphism. By analyzing genomic DNA or amplified genomic DNA, or amplified cDNA derived from platelet mRNA, it is possible to type glycoprotein GPIIIa with regard to the Pen polymorphism, for example, in the context of diagnosing and treating clinical syndromes associated with GPIIIa-related immune responses.

Abstract: A method for HLA typing by amplification of a sample followed by sequence-specific oligonucleotide hybridization with a labelled oligonucleotide probe provides for both positive and negative controls. Control sequences representing known allelic polymorphisms at the locus in question are subjected to the labelled probe along with the sample. This method reduces errors and improves the chance of obtaining a successful tissue match, as is vital in the case of tissue transplants, particularly bone marrow transplants. Probes and PCR primers useful in HLA-DR typing are also provided.