Significance of HLA-matching and anti-HLA antibodies in heart transplant patients receiving induction therapy?

OBJECTIVES: Though Human Leukocyte Antigen (HLA) matching benefits are demonstrated in renal transplantation, evidence in heart transplantation is lacking, and its clinical feasibility is uncertain. Post-transplantation anti-HLA antibodies are being increasingly studied in organ transplantation, with diverging conclusions between transplantated organs. METHODS: We analyzed retrospectively the influence of HLA matching and anti-HLA antibodies on overall survival, acute rejection and chronic allograft vasculopathy in 309 patients receiving induction therapy and triple-drug immunosuppression. RESULTS: The average number of HLA-A/B/DR mismatches between donor and recipient was 4.9 ± 1. The majority of mismatches was for Class I HLA-A/B with an average of 3.3, then for Class I HLA-DR with an average of 1.6. Overall, the HLA-A/-B/-DR mismatches had no influence on the cardiac allograft survival (p = 0.28). However, HLA-DR mismatches were negatively correlated to severe cellular and/or humoral allograft rejection (p = 0.04). Our analysis found anti-HLA antibodies in 27% of recipients, de novo anti-HLA antibodies in 16% of recipients, and donor-specific anti-HLA (DSA) antibodies in 8% of recipients. Furthermore, de novo DSA had no influence on the 5-year survival (78% with DSA vs. 92% without DSA; p = 0.49), which may be masked by the limited number of recipients in analysis By univariable analysis, anti-HLA antibodies (preexisting or de novo) unrelated or related to the donor had no influence on severe cellular and/or humoral rejection or on chronic allograft vasculopathy. CONCLUSIONS: HLA-DR mismatch was negatively correlated to severe cellular and/or humoral allograft rejection but had no influence on cardiac allograft survival. In this study, anti-HLA antibodies (preexisting or de novo) unrelated or related to the donor had no influence on cellular and/or humoral rejection or on chronic allograft vasculopathy. The results of this study add to the controversy on the impact of allo-antibodies in heart transplant recipients receiving induction therapy and contemporary immunosuppression.