Abstract: The present disclosure provides among other things immunoassays exhibiting reduced cross-reactivity with analyte metabolites. Additionally, the present disclosure provides diagnostic immunoassays to determine the concentration or level in a test sample of a hydrophobic drug that metabolizes in vivo or in vitro to form cross-reacting metabolites wherein cross-reactivity with such metabolites of the drug analyte is reduced. In particular, the disclosure provides such immunoassays where the hydrophobic drug is an immunosuppressant drug such as cyclosporine A.

Abstract: The present disclosure relates to isolated antibodies that can be used in an assay to determine the concentration levels of myeloperoxidase (MPO) in a test sample. Additionally, the present disclosure also relates to the use of improved test sample handling methods in assays in order to preserve the original MPO levels in the test sample.

Abstract: The present disclosure provides among other things immunoassays exhibiting reduced cross-reactivity with analyte metabolites. Additionally, the present disclosure provides diagnostic immunoassays to determine the concentration or level in a test sample of a hydrophobic drug that metabolizes in vivo or in vitro to form cross-reacting metabolites wherein cross-reactivity with such metabolites of the drug analyte is reduced. In particular, the disclosure provides such immunoassays where the hydrophobic drug is an immunosuppressant drug such as cyclosporine A.

Abstract: The invention provides a method for determining concentration of myeloperoxidase (MPO) in a human blood sample comprising: (a) providing a human peripheral blood sample stored under MPO preservation conditions; and (b) determining concentration of MPO in a plasma sample derived from the human peripheral blood sample. In a preferred embodiment, the MPO preservation conditions used in the invention comprise storage of the human peripheral blood sample in a plasma collection tube containing a leukocyte MPO secretion inhibitor. In this embodiment, the leukocyte MPO secretion inhibitor is preferably ethylene diamine tetraacetic acid (EDTA). The assays used in the inventive methods can comprise any clinically useful assay for determining MPO plasma concentration, including sandwich and competitive immunoassays, clinical chemistry assays and enzymatic assays.