METHODS AND COMPOSITIONS FOR ASSAYING ENZYMATIC ACTIVITY OF MYELOPEROXIDASE IN BLOOD SAMPLES

摘要

The present invention provides a two-step assay for measuring myeloperoxidase (MPO) activity in a blood sample. The first step utilizes a chromogenic substrate to measure first peroxidase activity including MPO activity in the sample, whereas the second step measures non-MPO peroxidase activity in the presence of the same chromogenic substrate and a specific MPO inhibitor. Specific MPO peroxidase activity is then determined by comparing the non-MPO peroxidase activity and the total peroxidase activity. The MPO peroxidase activity obtained in this fashion may be proportional, and preferably directly proportional, to the mass of MPO in the sample. Kits for assaying MPO peroxidase activity based on the same principle are also provided.