The Incidence of Hemolytic and Serologic Transfusion Reactions Among Patients with Hematological Malignancies at Mbarara Regional Referral Hospital and the Uganda Cancer Institute, in Uganda

Background: Blood transfusions are essential in the supportive care of patients with hematological malignancies but carry a risk of adverse reactions. Data on the incidence of transfusion reactions remain scarce in Uganda. This study evaluated the incidence of hemolytic and serologic transfusion reactions among patients with hematological malignancies at Mbarara Regional Referral Hospital and the Uganda Cancer Institute in Uganda. Materials and Methods: This prospective cohort study enrolled hospitalized patients aged ≥ 2 years with hematological malignancies and a history of prior red blood cell (RBC) transfusions. Participants received additional transfusions and were monitored for up to 14 days. Blood samples were collected on day 0 (transfusion day), days 7, and 14 to assess hemoglobin (Hb) levels, lactate dehydrogenase (LDH), and perform direct and indirect antiglobulin tests. Participants’ medical records were also reviewed for transfusion and pregnancy histories. Repeated Measures-Analysis of Variance was used to compare mean Hb and LDH levels over time points. Results: Of the 467 participants enrolled (median age: 36.4 years, interquartile range: 27.3– 46.9), 382 completed the follow-up period. A progressive increase in mean Hb levels (g/dL) was observed: 6.6 (95% confidence interval CI: 6.1– 8.9) on day 0, 7.5 (7.3– 10.1) on day 7, and 8.9 (8.4– 10.6) on day 14. No acute or delayed hemolytic reactions occurred. The incidence of delayed serologic transfusion reactions (DSTRs) was 0.86 in 100 (95% CI: 0.02– 1.69), while the overall RBC alloantibody prevalence was 2.4% (95% CI: 0.98– 3.74). The identified alloantibodies were directed against antigens in the Rh, Kell, Lewis, and MNS group systems. Conclusion: Despite a low incidence of DSTRs, a notable prevalence of RBC alloimmunization was observed among patients with hematological malignancies. These findings underscore the need to strengthen pre-transfusion antibody testing to prevent hemolytic complications and improve transfusion outcomes in this population. Keywords: hematological malignancies, transfusion reactions, Uganda