Cytosolic free calcium changes induced by chemotactic peptide in neutrophils from patients with chronic granulomatous disease.

Cytoplasmic free calcium concentration (Ca2+)i was measured in neutrophils from patients with the classical X-linked form of chronic granulomatous disease (CGD) by trapping the fluorescent calcium indicator Quin 2 in intact cells. CGD neutrophils do not produce superoxide and are only slightly depolarized upon stimulation by the chemotactic peptide. N-formyl-methionyl-leucyl-phenylalanine (FMLP). The resting levels, as well as (Ca2+)i changes induced by FMLP in CGD cells, were quantitatively and kinetically similar to those observed in normal cells. We conclude that the defect in CGD cells is distal to, or independent of, the changes in (Ca2+)i induced by FMLP stimulation and that normal membrane depolarization does not seem to be necessary for receptor-mediated rise in free cytosolic calcium in human neutrophils.