Impact of the Banff '97 classification for histological diagnosis of rejection on clinical outcome and renal function parameters after kidney transplantation

Background. Data on a systematic correlation of specific pathomorphologic l esions in renal allograft biopsy specimens with clinical outcome parameters are crucial to determine the relevance of kidney biopsy findings after tra nsplantation for graft prognosis. Specific histologic lesions of the revise d Banff '97 classification were correlated with clinical follow-up data. Methods. The analysis was done on a series of 48 consecutive renal allograf t biopsy specimens. Logistic regression was used to compare for response to rejection treatment dependent on histologic grading. Cox regression was ap plied to analyze the impact of the histologic findings on graft failure dur ing ongoing follow-up. Results. Severity of acute rejection was statistically associated with unre sponsiveness to antirejection treatment (odds ratio 2.39, 95% confidence in terval 1.13-5.03) and predicted an increased risk of graft failure (hazard ratio 2.16, 95% confidence interval 1.48-3.14). Intimal arteritis (hazard r atio 1.85, 95% confidence interval 1.40 -2.45) was the only determinate of a poor survival prognosis. Mean serum creatinine level and the need for ant ihypertensive drugs were significantly higher in the Banff I-III graded gro ups after 1 and 2 years of follow-up, whereas patients with borderline reje ction were not significantly different from the control group. Conclusion. We confirmed a significant association between the revised Banf f '97 classification and graft outcome. Intimal arteritis was the only sign ificant predictor of a poor survival probability. The distinction of border line rejection and Banff grade I rejection seems to be important from a pro gnostic point of view.