Impact of HLA Antibodies on Graft Survival in Long-Term Renal Recipients with Functional Grafts

Abstract

Objectives: Accumulating evidence supports the hypothesis that HLA antibodies play an important role in early renal allograft injury. However, the effects of HLA antibodies on long-term graft survival are still poorly understood. In this study, we examined the impact of HLA antibodies on graft survival in long-term renal recipients with functional grafts for 10 years. Material and Methods: In this retrospective study, long-term renal recipients were defined as kidney transplant recipients who had normally functioning renal grafts (serum creatinine level <2.0 mg/dl) for 10 years. Posttransplant serum samples from a total of 92 long-term renal allograft recipients on cyclosporine-based triple maintenance drug therapy (121.6 ± 0.886 months) were screened for the specificities of anti-HLA antibodies. The results of HLA antibodies before the transplantation, assessed using the same test method, were compared with those after their transplantations. Moreover, these 92 patients who received cadaveric renal transplant between January 2000 and December 2002 were followed up for about 10 years (range 107-135 months). Results: 27 patients had HLA-I antibodies and 16 patients had HLA-II antibodies before the transplantation, whereas 12 patients had HLA-I antibodies and 18 patients had HLA-II antibodies after the transplantation. Moreover, the types of HLA antibodies were different from those found before the transplantation. In these renal recipients with functioning renal grafts, the estimated glomerular filtration rate was 66.52 ± 14.52 ml/min/1.73 m² in the HLA antibody-positive group (n = 23) and 69.09 ± 25.54 ml/min/1.73 m² negative in the HLA antibody-negative group (n = 69, p > 0.05). Three patients (3.26%) (3 out of 92) had donor-specific anti-HLA antibodies (DSA). The frequency of DSA in this study was lower than that in the general Chinese Han renal recipient population. Conclusions: We find that all HLA antibodies in the long-term renal grafts are newly formed after the transplantation. The HLA antibody status has little impact on the renal graft function in the long-term renal recipients.