Antigen-positive platelet transfusion in neonatal alloimmune thrombocytopenia (NAIT)

Neonatal alloimmune thrombocytopenia (NAIT) is a fetomaternal incompatibility most commonly induced by maternal anti-HPA-1a, IgG alloantibodies against a polymorphic epitope of the glycoprotein IIb/IIIa complex in approximately 97.5% of white patients. Current guidelines recommend transfusion of immunologically compatible platelets to prevent cerebral hemorrhage, the most severe complication in affected newborns. Such platelet concentrates, however, are often not readily available. In a retrospective analysis in German and Canadian centers, 27 newborns with NAIT were identified who received platelets from random donors. Unexpectedly, 24 of 27 newborns showed an increase above a threshold of 40 x 10(9) platelets per liter, with moderate (n = 8) or significant (n = 16) platelet count increments (more than 80 x 10(9)/L). We conclude that transfusion of platelet concentrates from random donors is an appropriate strategy in the management of unexpected, severe NAIT predominantly in first pregnancies, pending the availability of compatible platelets.