ABO non-identical platelet transfusions, immune platelet refractoriness and platelet support.

ABO-non-identical (ABO-ni) platelets may be another risk factor for immune platelet transfusion refractoriness (i-PTR). We examined the effect of such platelets on i-PTR and subsequent platelet support through retrospective analysis of 17 322 New Zealand patients receiving ≥1 platelets. Immune PTR was defined as PTR with anti-HLA-I/HPA positivity.