ABO-identical versus incompatible platelet transfusion in patients with intracranial hemorrhage.

Background: Patients with spontaneous and traumatic intracranial hemorrhage (ICH) are frequently transfused platelets to treat thrombocytopenia, platelet function defects, and reverse antiplatelet drugs. ABO-identical platelet transfusion has been suggested to lead to higher post-transfusion platelet increments compared to major-ABO incompatible transfusion. We hypothesized that patients who received ABO-identical transfusion would have higher post-transfusion platelet increments and superior neurologic outcomes.

Methods: Adults with traumatic or non-traumatic ICH from January 1st 2018 to December 31st 2022 were identified using electronic medical records and international classification of disease (ICD)-10 codes. Patients were excluded if they lacked a platelet count within 24 hours before and within 24 hours after transfusion or if they received multiple platelet transfusions before their platelet count was remeasured. After stratification by ABO-identical, ABO-major incompatible, and ABO-minor incompatible transfusion, post transfusion increments were compared, as were clinical outcomes.

Results: Among 167 patients who received platelet transfusion, 76 (45.5%) received ABO-identical transfusion, 54 (32.3%) received ABO-major incompatible transfusion, and 37 (22.2%) received ABO-minor incompatible transfusion. There were no significant differences in absolute platelet increment between groups. The median increment was 7x109/L for ABO-identical platelets, 10x109/L for ABO-major incompatible platelets, and 11x109/L for ABO-minor incompatible platelets, p = .87. There was no significant difference in the percentage of patients discharged alive with modified Rankin score of 1 or 2 or cerebral performance category 1 or 2 between groups (p = .56 and .39 respectively). After adjusting for confounders in a general linear model there remained no associations between ABO compatibility and platelet increment after transfusion.

Conclusions: Our data support similar efficacy for ABO-identical and ABO-incompatible platelet transfusion in patients with ICH.