{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Myeloperoxidase (MPO) is a peroxidase enzyme most abundantly present in neutrophil granulocytes. It is a lysosomal protein stored in azurophilic granules of the neutrophil. MPO has a heme pigment, which causes its green color in secretions rich in neutrophils, such as pus and some forms of mucus. MPO antibodies detect granulocytes and monocytes in blood and precursors of granulocytes in the bone marrow."}]}]}