Risk factors for red blood cell alloimmunization in patients with hematologic malignancy

Abstract Introduction Patients with hematologic malignancy have a higher risk of developing red blood cell (RBC) alloimmunization which can delay blood transfusion. Information on the risk factors for alloimmunization in this group is still limited. This study aimed to determine the prevalence and predictors of RBC alloimmunization among these patients. Materials and Methods Electronic medical records of the patients with acute myeloid leukaemia (AML), acute lymphoid leukaemia (ALL), multiple myeloma (MM) and lymphoma from a tertiary care hospital between January 2018 and December 2022 were retrospectively reviewed. Clinical, demographic and transfusion history data of the included patients were analysed. Results Of the 983 patients with hematologic malignancy, 798 were included in the study. The prevalence of RBC alloantibodies in this population was 4.8% (38 patients). The alloimmunization rate of each subgroup was as followed: AML 9.1%, ALL 2.9%, MM 3.8% and lymphoma 2.5%. The most common alloantibodies were anti‐Mi a , anti‐E and anti‐Le a . The majority (29/38, 76.3%) of alloimmunization had a single alloantibody. RBC autoantibody was detected in 10 patients. The detection of autoantibodies and having AML were independently associated with RBC alloimmunization (adjusted odds ratio aOR 13.41, 95% confidence interval CI 2.00–89.72, p = 0.007 and aOR 11.44, 95% CI 2.02–64.72, p = 0.006, respectively). Conclusion The prevalence of RBC alloimmunization in the patients with hematologic malignancy was 4.8%. The alloimmunization rate of the AML subgroup was higher than those of other hematologic malignancies. The detection of autoantibodies and the AML diagnosis were identified as potential risk factors for RBC alloimmunization.