History matters: Preventing severe allergic transfusion reactions

Objective Prior studies have shown that pretransfusion medication is not effective in preventing allergic transfusion reactions (ATRs), but these studies did not consider the patient’s history of ATR. This study evaluated whether pretransfusion antiallergy medications decrease the chance of ATRs in patients with a history of severe ATR. Methods This single-center, retrospective study investigated the effect of pretransfusion medications on preventing ATRs in patients with a history of at least 1 severe ATR between March 2018 and January 2024. Patient demographics as well as clinical and transfusion reaction data were collected from our electronic health record (EHR) system. Data were analyzed using SPSS (IBM Corp) and machine learning in Python, version 3.12.4. Results In our cohort, 53 patients aged 5 weeks to 94 years with 2767 analyzable transfusion encounters had experienced 88 lifelong mild and severe ATRs. Premedication (P = .021), regular antiallergy medication (P < .001), and washing/volume reduction (P = .032) were associated with a statistically significantly lower chance of developing ATRs in our patient population. Conclusions Patients with at least 1 severe ATR benefit from pretransfusion administration of antiallergy medications.