Heterogeneity of peroxidase positive granules in normal and pathologic human neutrophils

Studies have demonstrated significant heterogeneity in neutrophil granule morphology and physical density. Using cytochemical methods to localize peroxidase and vicinal glycol containing complex carbohydrates we examined the heterogeneity of neutrophil granules from intact human neutrophil granules in 13 isolated granule density fractions, calcium ionophore A23187 treated neutrophils and neutrophils from patients with Chediak-Higashi Syndrome and Specific Granule Deficiency. At least four distinct populations of peroxidase positive granules (PPG) were identified based on peroxidase staining, vicinal glycol staining, morphology, beta-glucuronidase and defensin content, and physical density characteristics. The smallest (0.15 micron diameter) PPG was the least dense granule, had a unique peroxidase/beta-glucuronidase ratio, reacted intensely for vicinal glycols, resisted ionophore degranulation and was not consumed in giant granule formation in Chediak-Higashi Syndrome. The largest (0.3 micron average diameter) and most physically dense PPG was rich in defensins, stained weakly for vicinal glycols, and was absent in specific granule deficiency. These studies demonstrate and correlate morphologic, biochemical, functional, and pathologic differences in PPG populations.