ABO-identical versus nonidentical platelet transfusion: a systematic review

BACKGROUND: The significance of ABO matching for platelet (PLT) transfusion has not been clearly defined. The primary objective of this report is to assess whether ABO-identical PLT transfusion is associated with improved mortality and/or morbidity for patients with hematologic/oncologic disorders. STUDY DESIGN AND METHODS: A systematic review to January 2009 was conducted. Data on mortality, morbidity, PLT refractoriness, and PLT increment after transfusion were abstracted. RESULTS: A total of 100 citations were identified. Nineteen studies were included in the systematic review. A total of 1502 patients from three randomized controlled trials and 16 observational studies were included. Survival, bleeding events, and transfusion reactions were only considered as secondary outcomes in the reports reviewed. The PLT count increment was the primary outcome of several studies and was consistently higher with ABO-identical PLT transfusion. The largest difference in increment between ABO-identical and nonidentical PLT transfusion was 4 x 109/L. No consistent benefit in clinical outcomes was noted. Survival was assessed in three reports with conflicting results. Although two studies described bleeding as an outcome, the assessment of hemorrhage was considered inadequate. In six studies, ABO-nonidentical PLT transfusion was not associated with transfusion reactions, and the results from four studies addressing the impact of ABO-identical PLT transfusion on PLT and red blood cell utilization were conflicting. CONCLUSION: ABO-identical PLT transfusion results in a higher PLT increment. Randomized controlled trials are required to definitely determine the effect of ABO-identical PLT transfusion on survival, bleeding events, or transfusion reactions.