Alloimmune neonatal neutropenia: clinical observations and therapeutic consequences.

Alloimmune neonatal neutropenia is a rare condition, it must be distinguished from hereditary forms of neutropenia and acquired neutropenia accompanying sepsis. In a family with four affected newborns, the degree of the disease became more and more severe from the first child to the third child. The third child died of sepsis. After birth of the third child, specific antibodies (anti-NA 1) reacting with the neutrophils originating from the father and the first two children were detected in the mother's serum. No neutrophils were detectable in the fourth child immediately after birth. In this child falling concentrations of diaplacentally transferred antibodies could be demonstrated over 8 weeks after birth. Neutrophil counts returned to normal as the antibodies disappeared. In this newborn, infection could be prevented by the use of a germ-free environment and antimicrobial prophylaxis. The antibody titres could only be lowered by repeated exchange transfusions with Na 1-free blood. White blood cell transfusion only resulted in a short transient effect on neutropenia.