Natural history of primary autoimmune neutropenia in infancy.

Five patients with primary autoimmune neutropenia were evaluated during their first 2 years of life. Their illness resolved spontaneously after 6 to 41 months (median 13 months), and the patients were subsequently followed for 13 to 73 months (median 28 months). None required immunosuppressive therapy to induce remission, and routine antibiotic therapy adequately controlled all infectious episodes. An increased rate of infection, particularly otitis media and upper respiratory tract infection, occurred during the neutropenic period. No other noninfectious illnesses, particularly no other autoimmune diseases, were reported in any of these patients at any time. In each case, resolution of neutropenia paralleled the disappearance of neutrophil autoantibodies which were specific for the NA1 antigen. This report describes the clinical and laboratory findings and the long-term history of primary autoimmune neutropenia in these five patients.