ABO incompatibility and component irradiation are independently associated with platelet transfusion reaction rate

Allocating incompatible platelet components to avoid product wastage must be balanced against the risk of reduced efficacy and adverse outcomes. The impact of platelet compatibility in association with product irradiation or pathogen reduction is unknown. This study aims to determine the combined and independent impact of platelet compatibility and component modification on transfusion reaction rate. A retrospective review of all adult platelet transfusions from 2020 to 2022 was performed, including all reported reactions. Logistic regression was performed to evaluate the significance of ABO compatibility and unit modification for reaction rate. Out of 21,330 transfusions to 3450 patients, 285 (1.33%) reactions were reported and 178 (0.83%) were diagnosed as related to transfusion, predominantly febrile nonhemolytic (n = 59) and allergic (n = 102). The compatibility of transfusion was 67.7% ABO identical, 13.8% ABO minor incompatible, 17.2% ABO major incompatible, and 1.4% ABO bidirectionally incompatible. Irradiated, unmodified, and pathogen-reduced single-donor platelets were transfused in 70.9%, 21.8%, and 7.3% of cases, respectively. Univariable regression demonstrated increased odds of reaction for major incompatibility vs. ABO identical (OR: 1.92; 95% CI: 1.36-2.71) and irradiated vs. unmodified (OR: 2.34; 95% CI: 1.45-3.91), which were confirmed by multivariable analysis. The effect of compatibility and unit modification were independent in all analyses. The results demonstrate a trend of increasing reaction rate associated with major incompatibility and product irradiation. This study provides additional data to inform institutional policies guiding product selection for individual patients.