Figure 2.

 Neutrophil oxidative burst activity; neutrophil counts (y axis) and log scale of arbitrary units of fluorescence (x axis). (A–C) Before (shaded) and after (unshaded area) stimulation of neutrophils loaded with dihydrorodamine (DHR) with phorbol myristate acetate. (A) Increased fluorescence of all neutrophils in a healthy person (father). (B) No increase in fluorescence on stimulation suggesting chronic granulomatous disease (CGD; affected cousin). (C) Most neutrophils responding to stimulation with increased fluorescence, with a shoulder of less responsive neutrophils suggesting X linked CGD carrier status (identical for mother and her sister). (D,E) Staining of neutrophils with monoclonal antibody 7D5 specific for gp-91^phox.³ (D) Two peaks shown by the normal control (the higher peak represents high gp-91^phox expression by eosinophils). (E) Three peaks shown by the carrier (mother): the “negative” peak (gp-91^phox negative neutrophils), the “positive” peak (gp-91^phox positive neutrophils), and the higher “positive” peak (eosinophils). The low oxidase activity seen in the DHR test in both carriers can be explained by the carryover of hydrogen peroxide from the normal cells to the oxidase negative cells, which leads to some DHR oxidation inside the oxidase negative cells. The 7D5 monoclonal antibody test confirms the existence of gp-91^phox negative and gp-91^phox positive neutrophils, suggesting that this mutation in CYBB prevents gp-91^phox expression.