Objective: To assess the influence of times and duration of acute rejection episodes and the effect of antirejection therapy in renal transplantation recipients on the long-term survival of renal allograft.
Methods: The clinical data of 946 patients who received renal transplantation were analyzed to analyze the survival of renal allograts in different conditions: times of rejection episode, time of onset of acute rejection, and effect of antirejection therapy by life table and Wilcoxon test, and to identify the risk factors through Cox regression analysis.
Results: During the follow-up with a range of 3 approximately 158 months acute rejection occurred in 172 patients. The 946 cases of kidney transplantation were divided into rejection free group (NAR, n = 774), one time rejection group (1AR, n = 159), and twice and more rejection group (2AR, n = 13) according to the times of rejection. The 1AR group was subdivided into completely reversed group (CAR) and incompletely reversed group (1AR). The 1AR cases were subdivided into early-stage rejection group (EAR, with episode within 90 days after transplantation, n = 112) and late-stage rejection group (LAR, with episode 90 days later transplantation, n = 47) according to the onset time of rejection episode. The five-year survival rate was 70.9% in the AR group (n = 172) and was 93.3% in the NAR group (P < 0.000 1). The ten-year survival rate of renal allografts was 29.8% in the AR group, and was 83.3% in the NAR group (P < 0.000 1). The 5-year survival rate of renal allograft was less than 30% in the 2AR group, significantly lower than those in the NAR and IAR groups (P < 0.000 1 and P< 0.003). The 5-year survival rate of renal allograft was 89.0% in the EAR group, significantly higher than that in the LAR group (48.9%, P < 0.000 1). The 8-year survival rate was 84.3% in the EAR group, significantly higher than that in the LAR group (32.1%, P < 0.000 1). Both the survival rates of renal allograft in the EAR and LAR groups were significantly lower than that in the NAR group (P = 0.025 and P < 0.000 1). The condition had been completely reversed in 95 patients and incompletely reversed in 54 patients, and failed to be improved in 10 patients out of the 159 cases in the IAR group after antirejection therapy. The 5-year survival rate of renal allograft was 93.9% in the CAR group, significantly higher than that in the IAR group (63.1%, P < 0.000 1) but not significantly different from that in the NAR group (P = 0.96). The 8-year survival rate of renal allograft was 89.2% in the CAR group, significantly higher than that in the IAR group (41.4%, P < 0.000 1) but not significantly different from that in the NAR group (P = 0.96). The time of rejection onset was not the main factor effecting survival rate of grafts. The main risk factor influencing the long-term survival of renal allograft was the therapeutic effect after the onset of rejection with a risk rate of 3.14.
Conclusion: The acutely rejected renal allografts have poor long-term survival. The long-term survival rate of renal allograts with acute rejection that occurs only once and is completely recovered after antirejection therapy is not significantly different from that of the renal allografts in NAR group.