Impacts of ABO Incompatible Platelet Transfusions on Platelet Recovery and Outcomes after Intracerebral Hemorrhage.

ABSTRACT Acute platelet transfusion after intracerebral hemorrhage (ICH)given in efforts to reverse antiplatelet medication effectsand prevent ongoing bleeding does not appear to improve outcomeand may be associated with harm. Although the underlying mechanisms are unclear, the influence of ABO-incompatible platelet transfusions on ICH outcomes has not been investigated. We hypothesized that ICH patients who receive ABO-incompatible platelet transfusions would have worse platelet recovery (using absolute count increment [ACI]) and neurological outcomes(mortality and poor modified Rankin Scale [mRS 4-6]) as compared to those receiving ABO-compatible transfusions. In a single center cohort of consecutively admitted ICH patients, we identified 125 patients receiving acute platelet transfusions, of whom 47 (38%) received an ABO-incompatible transfusion. Using quantile regression, we identified an association of ABO-incompatible platelet transfusionwith lower platelet recovery (ACI: 2×103cells/μL vs 15×103cells/μL; adjusted coefficient β:−19; 95%CI:−35.55 to −4.44; p=0.01). ABO-incompatible platelet transfusion was also associated with increased odds of mortality (adjusted OR 2.59; 95%CI: 1.00–6.73; p=0.05) and poor mRS (adjusted OR 3.61; 95%CI: 0.97–13.42; p=0.06), however these estimates were imprecise. Together, these findings suggest the importance of ABO-compatibility for platelet transfusionsfor ICH;however, further investigation into the mechanism(s) underlying these observations is required.