DIAGNOSIS AND CLINICAL COURSE OF AUTOIMMUNE NEUTROPENIA IN INFANCY - ANALYSIS OF 240 CASES

Primary autoimmune neutropenia (AIN) is caused by granulocyte-specific autoantibodies and occurs predominantly in infancy. Clinical presenta tion and diagnosis have not been well established, resulting in burden ing diagnostic investigations and unnecessary treatment with granulocy te colony-stimulating factor (G-CSF). In the present study, clinical, laboratory, and immunologic data of 240 infants with primary AIN were evaluated. Suspected association with parvovirus B19 infection was inv estigated using serologic and DMA-based methods. Primary AIN was mainl y diagnosed at the age of 5 to 15 months but was observed as early as day 33 of life. In 90% of the cases, AIN was associated with benign in fections despite severe neutropenia. Spontaneous remission, shown by 9 5% of the patients, usually occurred within 7 to 24 months. Autoantibo dies in the patient's sera were not always present, and screening had to be repeated several times until antibody detection succeeded. About 35% of the autoantibodies showed preferential binding to granulocytes from NA1 and NA2 homozygous donors. Bone marrow was typically normoce llular or hypercellular, with a variably diminished number of segmente d granulocytes. A significant association with parvovirus B19 infectio n was not found. Symptomatic treatment with antibiotics was sufficient in most patients. Eighty-nine percent of the patients received antibi otics (cotrimoxazole) for prophylaxis of infections. For severe infect ions or for surgical preparation, G-CSF, corticosteroids, and intraven ous IgG were administered, resulting in increased neutrophil counts in 100%, 75%, and 50% of the patients treated, respectively. In combinat ion with the detection of granulocyte-specific antibodies, the typical clinical picture allowed diagnosis of AIN without burdening investiga tions. Treatment with G-CSF was found to be a reliable alternative to temporarily increase the neutrophil count. (C) 1998 by The American So ciety of Hematology.