[Detection of antineutrophil antibodies in patients with neutropenia in infancy]

Antineutrophil antibodies in the sera against peripheral blood neutrophils were examined in 8 infants (2 to 12 months of age) with neutropenia (absolute neutrophil count 0 to 480/microliter). The antibodies were detected by granulocyte indirect immunofluorescence test (GIIFT) and microleukocyte agglutination test (M-LAT). Three of the 6 serum samples with chronic benign-type neutropenia reacted in both GIIFT and M-LAT. In 2 of these 3 samples, the antibody was proved to be specific to neutrophil antigen NA1 by the absorption experiment. Neither the GIIFT nor the M-LAT showed the antibody in two patients with Kostmann-type neutropenia. These results suggest that the examination of antibodies against neutrophils is essential to the evaluation of the patients with chronic benign-type neutropenia in infancy.