Risk factors predicting chronic rejection of renal allografts

Chronic rejection is clinically defined as a gradual but progressive impairment of renal allograft function in the absence of other specific causes. The risk factors predisposing to chronic rejection are incompletely known. In this prospective single-center project, logistic regression analysis was used to study the long-term outcome of 94 consecutive first renal allografts in relation to 10 potential risk factors. Whether serum lipid levels, histopathological changes or the mode of immunosuppressive therapy had a predictive value for chronic rejection was of special interest. The risk factors for renal allograft outcome were determined 2 years after the transplantation, when graft function was still normal, and the results were evaluated 2 years later. Occurrence of acute rejections, cold ischemia time, the high-density lipoprotein cholesterol level, and the high-density lipoprotein and total cholesterol ratio were not significant predictors of graft outcome. In a univariate analysis, triglyceride, total cholesterol, and low-density lipoprotein cholesterol level, and donor age were significantly related to graft outcome. In a logistic regression analysis, triple immunosuppressive therapy was better than any double-drug regimen in preventing the deterioration of renal allografts. Incipient histological changes in graft biopsy, quantitated as the "chronic allograft damage index," was the most important single predictor of chronic rejection. The effect of both the histological changes and low-density lipoprotein cholesterol on adverse graft outcome was level dependent.