Long-term results of abo-incompatible living kidney transplantation : A single-center experience

Despite great efforts to promote the donation of cadaveric organs, the number of organ transplantations in Japan is not increasing and a serious shortage of cadaveric organs exists. These circumstances have forced a widening of indications for kidney transplantation. For this purpose, ABO-incompatible living kidney transplantations (LKTs) have been performed. Although we have already reported the short-term results of ABO-incompatible LKT, there is no report of long-term results in such cases; anti-A and anti-B antibodies could cause antibody-induced chronic rejection and result in poor long-term graft survival. In this study, we have reviewed the long-term results of ABO-incompatible LKT and tried to identify the most important factors for long-term renal function in ABO-incompatible LKT. Sixty-seven patients with end-stage renal failure underwent ABO-incompatible living kidney transplantation at our institute between January, 1989, and December, 1995. The mean age was 34.9 years (range, 8-58 years), with 38 males and 29 females. Incompatibility in ABO blood group antigens was as follows: A1-->O, 23 patients; B-->O, 19 patients; A1B-->A1, 7 patients; B-->A1, 8 patients; A1-->B; 4 patients; A1B-->B, 4 patients; A1B-->O, 2 patients. The number of HLA-AB, and -DR mismatches were 1.6+/-1.1 and 0.76+/-0.6, respectively. Plasmapheresis and immunoadsorption were carried out to remove the anti-AB antibodies before the kidney transplantation. In the induction phase, methylprednisolone, cyclosporine, azathioprine, antilymphocyte globulin, and deoxyspergualin were used for immunosuppression. Local irradiation of the graft was performed at a dose of 150 rad, on the first, third, and fifth days after transplantation. Splenectomy was done at the time of kidney transplantation in all cases. Patient survival was 93% at 1 year and 91% at 8 years. Graft survival was 79% at 1, 2, 3, and 4 years, 75% at 5 and 6 years, and 73% at 7 and 8 years. Patient survival was not significantly different from that of ABO-compatible patients. However, graft survival was significantly different between ABO-incompatible grafts and ABO-compatible grafts. Specifically, ABO-incompatible transplant recipients experienced a significantly higher rate of early graft loss up to 3 years but showed an equivalent graft loss by year 4. Among 67 patients, 16 grafts were lost during the observation period. Loss was due to acute rejection in 5 patients, followed by chronic rejection in 5 patients and deat