Outcomes of De Novo Allograft Diabetic Nephropathy in Renal Allograft Recipients

Objectives: Despite increased use of diabetogenic immunosuppressive drugs and increased incidence of new-onset diabetes after transplant in renal allograft recipients, there are few case studies on the subject of de novo allograft diabetic nephropathy and interstitial fibrosis/tubular atrophy without specific glomerular changes. We sought to study the outcomes of allograft diabetic nephropathy and interstitial fibrosis/tubular atrophy without specific glomerular changes in patients with new-onset diabetes after transplant. Materials and Methods: We reviewed the case records of all new-onset diabetes after transplant patients who underwent graft biopsy for graft dysfunction from 1992 to 2010. We analyzed the clinical characteristics and outcomes of new-onset diabetes after transplant patients with de novo allograft diabetic nephropathy and interstitial fibrosis/tubular atrophy without specific glomerular changes. Results: Of the 1989 recipients, 421 patients developed new-onset diabetes after transplant and 26 underwent graft biopsy. Of the 26 patients, 9 had histopathologic evidence of de novo allograft diabetic nephropathy, and 17 had interstitial fibrosis/tubular atrophy without specific glomerular changes. The mean duration from transplant to developing novo allograft diabetic nephropathy was 115.2 months (range, 33-192 mo), and from developing new-onset diabetes after transplant to allograft diabetic nephropathy, was 109.66 months (range, 27-188.4 mo). Of the 9 patients with de novo allograft diabetic nephropathy, 3 died (33.3%), 2 reached end-stage renal disease (22.2%), and 4 remained stable (44.4%). Of the 17 with interstitial fibrosis/tubular atrophy, 2 died (11.7%), 5 developed end-stage renal disease (29.4%), and 10 remained stable on triple immunosuppression and insulin therapy during follow-up (58.8%). Conclusions: De novo allograft diabetic nephropathy is a significant cause of graft and patient loss in renal allograft recipients who develop new-onset diabetes after transplant.