Neonatal alloimmune thrombocytopenia involving HPA‐5b (Bra): A rare Japanese Case

Abstract
Neonatal alloimmune thrombocytopenia (NAIT) is caused by platelet antigen incompatibility between the mother and fetus. The frequency of NAIT varies among ethnic groups. In Caucasians, HPA‐5b (Bra) is the antigen that is second most frequently implicated. In Japan, NAIT due to anti‐HPA‐5b antibody is quite rare. The present case is the second case of Bra‐NAIT in Japanese and the first case serologically confirmed by monoclonal antibody‐specific immobilization of platelet antigens.