Myeloperoxidase modulates the phagocytic activity of polymorphonuclear neutrophil leukocytes. Studies with cells from a myeloperoxidase-deficient patient.

Abstract

Patients lacking the primary granulae enzyme, myeloperoxidase (MPO), do not usually show any increased susceptibility to infection or altered in- flammatory response, in contrast to several other bio- chemical defects in polymorphonuclear neutrophils. We have now evaluated the role of MPO on phagocyte func- tion in a patient with complete MPO deficiency suffering from generalized pustular psoriasis. We found that the MPO-deficient neutrophils showed enhanced phagocy- tosis (>200% ofnormal) ofIgG-and C3b-opsonized yeast particles and prolonged N-formylmethionyl-leucyl-phenylaline-mediated stimulation of superoxide production.