Granules which are Azurophilic
also seen in light blue cytoplasm.
MPO is an antimicrobial heme enzyme (MW = 144 kDa) present in the azurophilic
granules of neutrophils.
Further, an immunofluorescence study of NETs showed that NETs consist of azurophilic
(primary) granules such as cathepsin G, neutrophil elastase, and myeloperoxidase.
Upon activation, neutrophils release some of their MPO from azurophilic
granules into the blood.
The MPO is a hemecontaining enzyme, present in high quantities in the neutrophil azurophilic
granules, which catalyzes reactions of oxidation .
Cytoplasmic projections with tongue-like protrusions and fine or coarse cytoplasmic azurophilic
granules were also present (Figure 3).
Herwald, "Secretion of heparin-binding protein from human neutrophils is determined by its localization in azurophilic
granules and secretory vesicles," Blood, vol.
Diagnosis can be made with a simple peripheral smear for the classic giant azurophilic
granules, which are peroxidase-positive, in all granule-containing cells including the peripheral blood and bone marrow.
Myeloperoxidase is an enzyme found in azurophilic
granules of neutrophils (and less in monocytes) that also contain heme, but rather than being red-brown, it is yellow-green.
PR39, a proline- (P-)/arginine- (R-) rich antimicrobial peptide of 39 amino acids, was originally isolated from pig intestine and identified in neutrophil azurophilic
granules and macrophages [9,10].
MPO (myeloperoxidase) is a blood protein which exists in neutrophil azurophilic
granules and macrophage cells; level of MPO could reflect the infiltration degree of neutrophils in damage zone of tissue.
Neutrophil granulocytes have a high abundance of the enzyme MPO, constituting the majority of azurophilic