Oral Abstract
Transfusion Service - Patient Safety
Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare but frequently fatal transfusion reaction. Although γ-irradiation or pathogen-reduction technology (PRT) effectively prevents donor-derived lymphocyte proliferation, the practice of universal leukoreduction (LR) has coincided with a sharp decline in reported cases, prompting debate over whether LR alone might suffice. We performed a systematic review to characterize TA-GVHD in a contemporary time period and to identify cases occurring with non-irradiated, pre-storage LR cellular components, to evaluate the feasibility of estimating residual risk.
Study
Design/Methods:
A librarian developed the literature search strategy to retrieve all relevant records published August 1, 2013 – April 2, 2025 according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Searches were run in Ovid (Medline, Medline Epub Ahead of Print and In-Process, Embase), Web of Science, and Cochrane Central. No filters were used and grey literature was not searched. Reviewers independently screened records, and 2 study members extracted patient-level details, and classified each component by LR, irradiation, PRT, and donor relatedness status.
Results/Findings:
Of 3674 unique records, 20 met criteria, describing 41 TA-GVHD patients. Patient level data were available for 21 cases. Among 16 cases reporting irradiation status, 15 patients received non-irradiated products. Among 10 cases reporting LR status, 6 patients received non-LR products. Many patients received a mix of some irradiated and non-irradiated or some LR and non-LR products (designated as partial, figure 1). No cases reported component storage duration or pathogen-reduced status. Overall mortality was 75% (15 of 20 patients with outcome data). All 4 patients who received only LR products and developed TA-GVHD had weakened immune systems (lung transplant, leukemia, aplastic anemia, and severe combined immunodeficiency) and received non-irradiated products. No study provided a complete denominator of non-irradiated, pre-storage LR units; consequently, a formal incidence rate could not be calculated.
Conclusions:
TA-GVHD continues to arise, even after LR, when cellular components are transfused without irradiation or PRT, particularly in the setting of immunocompromise or immunodeficiency. The inability to pair numerators with reliable denominators remains the critical barrier to defining residual risk. Further, this era of transfusion has coincided with more strict criteria for irradiation, which improves patient safety and should not be waived, and limits evaluation to missed irradiation events. Robust hemovigilance systems that capture both component-level mitigation data and patient outcomes are essential before definitive judgments can be made about the standalone sufficiency of LR.