Human Leukocyte Antigens Sensitization in Kidney Transplant: Its Prevention and Challenges

The presence of donor-specific antibodies (DSAs) against human leukocyte antigens (HLA) indicates sensitization and poses a major barrier to successful transplantation. Sensitization may result from pregnancy, blood transfusion, prior transplantation, or infection, making it difficult to identify compatible donors and often prolonging waiting times. DSAs may be performed or developed de novo after transplantation. Preformed DSAs, generated from previous HLA exposure, are associated with early antibody-mediated rejection (ABMR). In contrast, de novo DSAs arise post-transplant due to HLA mismatches, inadequate immunosuppression, nonadherence, or graft inflammation, and are a key cause of late rejection and chronic graft injury. Advances in detection techniques, particularly solid-phase assays such as ELISA and Luminex single-antigen bead testing, have improved sensitivity and risk assessment. Preventive strategies include minimizing blood transfusions, using leukoreduced or HLA-matched blood products, and applying refined matching approaches such as eplet analysis to reduce alloimmunization and improve long-term transplant outcomes.