A family with allo-immune neonatal neutropenia: group-specific pathogenicity of maternal antibodies

A family is presented, in which the mother developed strong neutrophil granulocyte-specific antibodies with the specificity anti-NA. The first and third children, both NA1-positive, suffered from severe transient neonatal neutropenia, but the second child, NA1-negative, did not. Anti-NA1 antibodies were detectable in the serum of one affected child and the antibody level was directly related to the extent of neutropenia. The incidence of granulocyte-specific antibodies in 198 pregnant women was determined and found to be low.