Increased phagocytic activity of polymorphonuclear leukocytes of chronic granulomatous disease as determined with flow cytometric assay

Abstract

Using flow cytometry, we compared the phagocytic activity of polymorphonuclear leukocytes (PMNs) from healthy donors with that of PMNs from 10 patients with chronic granulomatous disease (CGD), eight carriers of X-linked CGD, and one patient with myeloperoxidase deficiency. Ingestion of fluorescent bacteria by CGD and myeloperoxidase-deficient PMNs was significantly increased, that is, about 1.5 times that of normal controls. In CGD carriers, two PMN populations were found: one population consisted of PMNs with enhanced phagocytosis, and the other consisted of PMNs with normal phagocytic activity. With a two-dimensional analysis, we also demonstrated in CGD carriers that phagocytosis of the PMNs that failed to generate hydrogen peroxide was significantly elevated, as was phagocytosis of PMNs in patients with CGD, while on the other hand, the PMNs that normally produced hydrogen peroxide exhibited a normal phagocytic activity. When sodium azide, an inhibitor of myeloperoxidase and catalase, was added to control and carrier PMNs, phagocytic activity was significantly increased, p less than 0.01 in both, but not to the level seen with CGD PMNs. Phagocytosis of CGD and myeloperoxidase-deficient PMNs, however, remained unchanged by the azide treatment. On the basis of above findings, we speculate that phagocytosis of CGD PMNs is increased because the H2O2-myeloperoxidase-halide system, which may modulate phagocytic activity of PMNs, fails to operate.