Neonatal alloimmune thrombocytopenia with significant HLA antibodies

A case of neonatal alloimmune thrombocytopenia (NAIT) secondary to human platelet antigen (HPA)-1a antibodies is reported. Additional multispecific HLA antibodies rendered volunteer donor platelet transfusions ineffective. Despite a high incidence of maternal HLA antibodies in the pregnant population, there is only one previous report of clinically significant HLA antibodies.