Successful Results After 5 Years of Tacrolimus Therapy in ABO-Incompatible Kidney Transplantation in Japan

In Japan, living donor kidney transplantation accounts for about 80% of all kidney transplants. This is in contrast to the United States and Europe, where transplantation of organs from cadaveric or brain-dead donors is more common. This study analyzed the results of 5 years of experience with tacrolimus in Japan, focusing on the efficacy of the drug in improving patient and graft survival in patients who underwent transplantation with ABO-incompatible kidney grafts. Of the 1542 evaluable patients, 1281 patients received grafts from living donors. Of these, 177 patients received kidneys from ABO-incompatible donors and 981 patients received kidneys from ABO-compatible donors. Graft survival rates in ABO-incompatible recipients ranged from 90.7% at 1 year to 80.5% at 5 years. Subsequent graft survival rates in ABO-compatible recipients were 98.1% and 92.9%, respectively (P < .001 between groups). Patient survival rates at 5 years were 93.2% in ABO-incompatible recipients and 98.1% in ABO-compatible recipients. The rejection rate for kidneys from ABO-compatible donors was 27.8%, while for ABO-incompatible donors the rejection rate was 45.2%. The excellent outcome from this study demonstrates that even suboptimal ABO-incompatible donors can be used successfully as a source of kidneys when using tacrolimus as the immunosuppressive regimen. This may go some way to addressing the shortage of kidney donors in Japan.