Prevalence of Clinically Significant anti-HLA Antibodies in Renal Transplant Patients: Single-center Report from North India

INTRODUCTION: Solid organ transplantation is the preferred therapeutic modality of treatment in patients affected by terminal organ failures. Human leukocyte antigens (HLAs) plays an important role in graft survival. In many of the cases of rejection, antibodies are directed against HLA antigens expressed on the cells of the transplanted organ. Pre-transplant compatibility testing involves the use of different methodologies for the determination of anti-HLA antibodies. Luminex single-antigen bead (SAB) assay demonstrates higher sensitivity and specificity in detecting anti-HLA antibodies. The aim of this study was to determine the prevalence of anti-HLA antibodies in pre-transplant work up recipients, planned for renal transplant at a tertiary care center in India. METHODS: 1640 patients visiting tertiary care hospital for pre-transplant compatibility testing were screened with complement-dependent micro-lymphocytotoxicity crossmatch (CDC-XM) and flow cytometric crossmatch (FC-XM). The patients positive for either or both screening tests were assayed with the Luminex SAB tests in order to establish defined antigen specificity of the alloantibodies and determining donor-specific antibody (DSA). RESULTS: The two most frequent antibodies identified in each A, B, C locus of HLA class I were -A*24:03 (43.9%), A*25:01 (36.6%), B*57:01 (40.3%), B*15:12 (37.1%), C*17:01 (61.9%), C*07:01 (52.4%) and in DR, DQ DP locus in HLA class II were DRB1*09:01(40.0%), DRB1*14:04(37.6%), DQA1*04:01/DQB1*03:03 (58.4%), DQA1*05:01/DQB1*03:01 (55.1%), DPA1*02:01/DPB1*17:01 (55.0%), DPA1*02:01/DPB1*05:01 (45.0%). CONCLUSION: This study has found the prevalence and specificity of anti-HLA antibodies in north India.