Are HPA‐5b antibodies a significant cause of FNAIT and associated bleeding or merely an incidental finding?

Keywords: human platelet antigens; fetal and neonatal alloimmune thrombocytopenia; HPA-5b EN human platelet antigens fetal and neonatal alloimmune thrombocytopenia HPA-5b 485 486 2 11/18/21 20211115 NES 211115 Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is caused by maternal IgG antibodies produced against incompatible human platelet antigens (HPA) on fetal platelets. This was probably because many hospital laboratories can detect HPA-1a antibodies using commercial platelet antibody detection kits and, therefore, reference laboratories like Sanquin receive fewer HPA-1a cases and more difficult FNAIT cases for testing. HPA antibodies were detected in maternal sera from 262 (14%) cases: 161 (61%) HPA-1a antibodies and 60 (23%) HPA-5b antibodies. [Extracted from the article]