Background: Neonatal alloimmune-mediated neutropenia (NAIN) due to maternal alloantibodies directed against one of the human neutrophil antigens (HNAs) can cause severe infections. NAIN has been described as caused by antibodies against HNA-1a, -b, -c, -2a, -3a, or -4a, but not by antibodies against HNA-5a.
Results: Blood from a 3-week-old newborn and from his parents was sent to our laboratory because of suspicion of NAIN. Granulocyte-specific antibodies were present in the maternal antiserum and reactive with the paternal granulocytes. The specificity of the maternal alloantibodies was shown to be anti-HNA-5a by the monoclonal antibody immobilization of granulocyte antigens assay. The mother was genotyped HNA-5a negative, and the father was genotyped homozygous HNA-5a positive.
Conclusion: We identified a first case of NAIN due to maternal alloantibodies against HNA-5a.
© 2010 American Association of Blood Banks.