The role of ABO matching in platelet transfusion

Abstract:  A prospective controlled trial was performed to determine whether the use of ABO‐identical platelets from the start of treatment might provide higher post‐transfusion platelet increments, reduce the number of platelet transfusions and ultimately delay the onset of refractoriness. Forty newly diagnosed patients with haematological diseases were randomized to receive either pooled ABO‐identical platelets or pooled platelets unmatched for ABO group throughout their course. The corrected platelet count increments (CCI) were calculated for the first 25 transfusions of each patient and non‐immune factors present at the time of each platelet transfusion were documented. The mean CCI for the first 25 transfusions in the ABO‐identical group was significantly higher (6600 ±: 7900 SD) than that achieved with ABO unmatched platelets (5200 ±: 7900; p<0.01). The effect was most marked for the first 10 transfusions for each patient where the CCI was 64% higher in the ABO‐identical group (8200 ±: 7500 vs 5000 ±: 8100; p<0.0002). Patients given ABO‐identical platelets required only about half as many transfusions in the first 30 days (10 versus 17, p<0.05) or during the first admission (11 versus 21 p<0.01) as patients in the ABO‐unmatched group. A smaller percentage of patients in the ABO‐identical group became refractory (36% vs 75% p<0.03). The data suggest that patients requiring long‐term platelet support should be transfused with ABO‐identical platelets.