Background: Human leukocyte antigen (HLA) alloimmunization can be induced by exposure to non-self HLA molecules, such as foreign tissue during transplantation, pregnancy, and blood products. Antibodies against HLA lead to serious complications in patients receiving blood transfusions.

Objective: The present study aimed to determine the prevalence and risk factors for HLA alloimmunization in multiple transfused patients with hematologic malignancies at Siriraj Hospital.

Materials and Methods: The present research was a cross-sectional study. The samples comprised 100 cases of hematologic malignancy patients who had a history of at least three episodes of transfusion with cellular blood components. All patients were tested for anti-HLA class I and class II antibodies by Luminex assay.

Results: The overall prevalence of HLA alloimmunization in multiple transfused patients with hematologic malignancies was 40%. Anti-HLA class I, class II, and both class I and class II antibodies were detected in 35%, 30%, and 25% of the patients, respectively. Factors related to the development of anti-HLA antibodies were previous pregnancy (OR 4.82, 95% CI 1.62 to 14.35, p=0.005), five or more transfusions (OR 7.82, 95% CI 2.22 to 27.55, p=0.001), and diagnoses with myelodysplastic syndromes (MDS) antibodies (OR 5.88, 95% CI 1.98 to 17.47, p=0.001).

Conclusion: Patients with hematologic malignancies who required long-term blood transfusion support could be at high risk for the development of anti-HLA antibodies. Important risk factors are pregnancy, multiple transfusions, and MDS.

Keywords: HLA alloimmunization, Anti-HLA antibodies, Blood transfusions, Hematologic malignancy

DOI: 10.35755/jmedassocthai.2023.11.13913

Received 24 July 2023 | Revised 29 September 2023 | Accepted 9 October 2023