Alloimmune neonatal neutropenia--a neglected diagnosis?

Alloimmune neonatal neutropenia is due to maternal IgG neutrophil-specific antibodies that cross the placenta to sensitize fetal neutrophils and cause neutropenia in the neonate. Within the first few weeks of life, the infant may succumb to localized or generalized bacterial infections. Haematologically, the mother is normal, but the infant is severely neutropenic. The incidence of this condition is one in 2000 neonates, but it can be overlooked easily if specialized testing is not performed in neonates with unexplained neutropenia. It is generally a self-limiting disorder, but severe infection may result in a 5% mortality. The clinical and serological features of four cases are described. The treatment of severe infections in infants with alloimmune neonatal neutropenia is essential, but the use of prophylactic antibiotic therapy during the period of neutropenia is not warranted.