Long dialysis duration improves the prognosis of subsequent renal transplantation

719 first cadaver renal transplantations between 1968-89 were reviewed to examine the effect of previous dialysis on graft prognosis. Longterm dialysis improved prognosis. 1 year graft survival was for short dialysis (S, 0-3 years) 54%; for medium (M, 3-5 years) 61%; for long (L, > 5 years) 66%. The five year survival was S:35%, M:41%, L:50% and the 10 year survival S:24%, M:32%, L:42%. The difference was mainly due to a 38% reduction in loss due to rejection during the first year, there being no difference in mortality. The number of acute rejections was also reduced (L: 0.52; M: 0.63; S: 0.82). There was no difference in transplantation date, recipient and donor age or sex, DR match, warm or cold ischemia or immunosuppressive therapy. L and M transplants had a poorer AB match (L: 1.49; M: 1.48; S: 1.82) and had a longer time to initial graft function (L: 8.2; M: 8.0; S: 5.0 days). Patients treated with HD had a better prognosis than PD*. However these patients were also younger, had shorter warm ischemia, had a later transplantation date and were treated more often with cyclosporine. There was no difference after CorreCtion for these factors. Conclusion: Long dialysis duration improves the prognosis of subsequent renal transplantation, presumably due to the well-known immunosuppressive effects of uremia per se. Dialysis modality has no impact on graft prognosis.