Impact of chronic allograft nephropathy and subsequent modifications of immunosuppressive therapy on late graft outcomes in renal transplantation.

BACKGROUND Chronic allograft nephropathy (CAN) is the leading cause of organ failure in renal transplant recipients. We retrospectively evaluated the impact of varying immunosuppression in CAN patients on long-term graft survival. METHODS We retrospectively analysed 158 cyclosporin (CsA)-treated renal transplant recipients with biopsy-proven CAN with follow-up of >1 year. Immunosuppression remained unchanged in 75 (NOVAR) and was modified in 83 patients (VAR). In 36.1% of VAR patients, it was increased; in 63.8%, the addition of other immunosuppressants was associated with a 20% reduction in or withdrawal of CsA. A regression model, for creatinine clearance (CrCl) slope analysis after therapy variation, and Cox's analysis were applied. RESULTS In VAR patients, two-phase regression did not show a correlation between the inflection point in the CrCl slope and treatment variation. Changing immunosuppression gave a borderline advantage in long-term graft survival compared with NOVAR (P = 0.088). In univariate analysis, severe histological lesions, proteinuria >0.5 g/day and CrCl <25 ml/min at biopsy correlated with poor graft outcome (P = 0.0009). In multivariate analysis, only proteinuria and low CrCl remained significative. Stratifying histological lesions in relation to therapy variation showed that severe lesions significantly decreased survival in both VAR and NOVAR groups; however, the highly negative impact of severe lesions in NOVAR patients on graft survival [relative risk (RR) 3.602] was reduced in VAR patients (RR 1.951), with a 10 year graft survival since biopsy of 0.16 vs 0.34 (P = 0.0001). CONCLUSIONS In transplant patients with CAN, variation of immunosuppression can reduce the negative impact of severe chronic lesions.