Platelet transfusion refractoriness associated with two rare platelet‐ specific alloantibodies (anti‐Baka and anti‐PlA2) and multiple HLA antibodies

A 65-year-old patient with pancytopenia resulting from osteomyelosclerosis became refractory to platelet transfusions during long-time transfusion support. He developed two rare, platelet-specific antibodies (anti-PlA2 and -Baka) disguised by strong, multispecific HLA antibodies. The specificity of the platelet-specific antibodies was detected by a newly designed enzyme-linked immunosorbent assay using glycoprotein-specific monoclonal antibodies for immobilization of platelet antigens.