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 lesions in renal allograft biopsy specimens with clinical outcome parameters are crucial to determine the relevance of kidney biopsy findings after transplantation for graft prognosis. Specific histologic lesions of the revised Banff '97 classification were correlated with clinical follow-up data. METHODS: The analysis was done on a series of 48 consecutive renal allograft biopsy specimens. Logistic regression was used to compare for response to rejection treatment dependent on histologic grading. Cox regression was applied to analyze the impact of the histologic findings on graft failure during ongoing follow-up. RESULTS: Severity of acute rejection was statistically associated with unresponsiveness to antirejection treatment (odds ratio 2.39, 95% confidence interval 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 ratio 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 antihypertensive drugs were significantly higher in the Banff I-III graded groups after 1 and 2 years of follow-up, whereas patients with borderline rejection were not significantly different from the control group. CONCLUSION: We confirmed a significant association between the revised Banff '97 classification and graft outcome. Intimal arteritis was the only significant predictor of a poor survival probability. The distinction of borderline rejection and Banff grade I rejection seems to be important from a prognostic point of view.