The clinical impact of chronic transplant glomerulopathy in cyclosporine era

Background. The clinical impact of chronic transplant glomerulopathy (CTG) on the outcome of kidney allograft receiving calcineurin inhibitors (CNIs) remains uncertain. A retrospective study of renal transplant recipients at Ospedale Maggiore of Milan was undertaken to evaluate the clinical outcome of patients with CTG. Methods. Among 666 biopsies taken at least 6 months after transplantation (Tx) in 498 transplant patients treated with CNIs, 28 cases (5.6%) of chronic transplant glomerulopathy (CTG) were identified and their clinical features at Tx, at follow-up and graft survival were compared with those of 56 controls transplanted in the same period and with kidney functioning 12 months after Tx. Clinical characteristics at biopsy and at 1 year after Tx were similar in the two groups. Results. After diagnosis graft function deteriorated in 22 patients (78.5%), while it remained stable in 6. Graft loss developed in 92% of patients with proteinuria >2.5 g/day and in 33% of those with lower proteinuria (P<0.005). In cases with more severe CTG the rate of graft loss was higher, though not significantly. Graft survival at 10 years was 48% in patients with CTG and 88% in controls (P<0.0001). Conclusions. The incidence and clinical course of CTG do not seem to be modified by CNI-based immunosuppression. The evolution is unpredictable but the severity of glomerulopathy and proteinuria at follow-up are associated with progression to graft failure. Patients with CTG have a graft survival significantly worse than that of the general population of transplanted patients.