Background: Current knowledge about the natural history, treatment and physicians' perception of chronic allograft nephropathy (CAN) is limited. The present study evaluated the prevalence and determinants of CAN in renal transplant patients.
Methods: Epidemiological, cross-sectional multi-centre study conducted in Spain. A total of 872 renal transplant recipients with a functioning graft and at least 2 years of post-transplant data on renal function were consecutively included. CAN diagnosis was recorded based on physician's clinical criteria and on laboratory criteria (serum creatinine ≥ 2 mg/dL and/or glomerular filtration rate ≤ 50 mL/min).
Results: The mean time from transplantation until the time of this study was 8.2 years. CAN was diagnosed in 35% of patients (n = 305) according to the physician's criteria (31% of whom with histological assessment) and in 55.5% (n = 482) according to laboratory objective criteria. An older donor age, lack of induction therapy, cyclosporine use, lower tacrolimus levels at 1 year, acute rejection, hypertension and worse initial renal function were associated with CAN development. Time from transplant to biopsy was greater in patients with anti-proteinuric treatment. Immunosuppression was modified in 46.9% of patients with CAN diagnosis [calcineurin inhibitor (CNI) reduction alone in 18.9% of cases; CNI reduction and mycophenolate modification in 17.8% and CNI reduction or withdrawal with introduction of proliferation signal inhibitors in 12.9%).
Conclusions: After ~8 years from renal transplantation, 55.5% of patients presented CAN, which was considerably underestimated by physicians. An older donor age and less initial immunosuppression seemed to be related to CAN development.