Eosinophil Peroxidase

Peripheral blood granulocytes are classified into neutrophils, basophils and eosinophils according to the staining characteristics of their cytoplasmic granules. Granule proteins are released by physiologic and pharmacologic stimuli and play important roles in both normal and pathological host immune responses. Eosinophil major basic protein and eosinophil peroxidase (EPX) are granule proteins specific to the eosinophil. AHE-1 recognizes human EPX, a granule protein specific to eosinophils. It does not cross-react with eosinophil major basic protein, elastase, cathepsin G, esterase N, thrombin, plasmin, kallikrein, lactoferrin, or transferrin. This MAb stains eosinophils only and does not stain other peripheral blood cells, including platelets, neutrophils, monocytes, lymphocytes or red blood cells. Human EPX gene product can form a tetramer of two light chains and two heavy chains. Other peroxidase family members include myeloperoxidase (MPO), lactoperoxidase (LPO), and thyroid peroxidase (TPO).