Neonatal alloimmune thrombocytopenia

Abstract

Neonatal alloimmune thrombocytopenia (NAIT), regarded as the platelet counterpart of hemolytic disease of the newborn (HDN), is the most common cause of severe thrombocytopenia in the neonatal period. During pregnancy, maternal alloantibodies are elicited against paternal specific platelet alloantigens on fetal platelets. The fetal thrombocytopenia is due to destruction by the macrophage system of fetal platelets coated with maternal alloantibodies which have crossed the placental barrier (1-3). Considering the pathogenesis, a more appropriate term for this condition is feto-maternal alloimmune thrombocyto- penia (FMAIT).