Reversal of neutropenia with intravenous gammaglobulin in autoimmune neutropenia of infancy.

Intravenous gammaglobulin (IVIgG) was used to treat autoimmune neutropenia of infancy in two males with repeated infections. The neutrophil count increased significantly in both patients with the initial IVIgG therapy; 1 patient went into remission. The neutrophil count in the other remained above baseline for 3 wk, and a subsequent booster infusion also caused the neutrophil count to increase. The patients have remained clinically well since their treatment began. Serial studies of antineutrophil antibody and serum lysozyme, performed to elucidate the mechanism of action, suggested decreased neutrophil destruction, perhaps by Fc receptor blockade, as well as decreased synthesis of antineutrophil antibody. Neutrophil function was not impaired after the neutrophil count increased. Many patients with immune neutropenia have a benign course, but those who have significant infections could be treated, acutely or prophylactically, with intravenous gammaglobulin.