ABO-incompatible kidney transplantation in Japan

Up to 2005, the number of patients on dialysis therapy exceeded more than 250,000 in Japan; however, only 200 deceased and 800 living kidney transplants have been performed annually. We have been making continuous efforts in ABO-incompatible kidney transplantation since 1989 to expand the opportunities for living kidney transplantation in Japan. From the Japanese registry, we have reviewed the long-term patient and graft outcome of ABO-incompatible kidney transplantation. This survey focused on 685 patients who received ABO-incompatible kidney grafts from January 1989 to December 2004 in whom monitoring follow-up could be achieved in 75 institutions. The overall patient survival rates at 1, 3, 5 and 10 years after transplantation were 94%, 91%, 87% and 82%, with overall graft survival rates of 87%, 83%, 76% and 57%, respectively. The graft survival rate was significantly higher in patients aged 29 and younger compared with those aged 30 and older. Especially in children aged 15 and younger, they have shown excellent graft survival rate. The patients with anticoagulation therapy showed significantly higher graft survival rate than those without anticoagulation. There were no significant differences between A- and B-incompatibility with respect to clinical outcomes. There were also no significant difference in numbers of HLA mismatches, induction and maintenance calcinurine inhibitors (ciclosporine vs. tacrolimus) and donor/recipient relationships with respect to the outcomes. A result of most recent 245 cases since 2001 had dramatically improved with 1-year graft survival is 96% and there is a significant difference between the groups in 2001 onwards and before. This study confirms that the outcome of ABO-incompatible living kidney transplantation in Japan is excellent and is similar to that in ABO-compatible cases. ABO-incompatible kidney transplantation has already become one of a standard, safety and effective treatment choice for end-stage renal disease.