Long-term results of living kidney transplantation from HLA-identical sibling donors under calcineurin inhibitor immunosuppression

Background: Recently, it has been revealed that alloantigen-independent causes are important factors for late graft loss in kidney transplantation. We compared the results of living kidney transplantation from HLA-identical siblings with those from HLA-nonidentical siblings to analyse the impact of alloantigen-independent factors on long-term graft survival. Methods: Two hundred and sixty-six recipients who were grafted from their siblings between 1983 and 2002 were subdivided into those transplanted from HLA-identical donors (n = 86) and those from HLA-non-identical donors (n = 180). Results: The incidence of acute rejection was significantly lower in the HLA-identical group than in the HLA-non-identical group (9.3% vs 53.9%, respectively; P < 0.0001). Graft survival was significantly higher in the HLA-identical group than in the HLA-non-identical group (91.3% vs 79.2% at 5 years, 80.3% vs 66.8% at 10 years and 59.1% vs 51.7% at 15 years, respectively; P = 0.0372). Although acute rejection was not seen as a cause of graft loss in the HLA-identical group, death with functioning graft, recurrence of the original disease or chronic allograft nephropathy were observed as the major causes of graft loss in the late period of the HLA-identical group. Conclusion: We concluded that alloantigen-independent causes constitute a crucial factor for graft loss in the late period of HLA-identical kidney transplantation.