Early onset of graft glomerulopathy in a patient with post-transplant diabetes mellitus after renal transplantation: A case report

Background: Post-transplant diabetes mellitus (PTDM) is an emerging problem in kidney transplantation, representing an important risk factor for kidney function loss. Diabetic nephropathy (DN) occurrence in transplanted kidneys is poorly investigated. Current knowledge describes DN recurrence in graft 5.9 years from kidney transplantation however there is little data about PTDM and DN. Here, we report a clinical case peculiar for an early appearance of advanced glomerular diabetic lesions, after kidney transplantation. Case presentation: A 45-year-old Caucasian male affected by autosomal polycystic kidney disease was transplanted with a cadaveric-kidney-donor from 58-year-old male. Induction immunosuppressive therapy included basiliximab and steroids while the maintenance treatment included, tacrolimus, mofetil micophenolate and methylprednisolone. One month after transplantation the patient developed diabetes requiring treatment with repaglinide quickly replaced with insulin to obtain an acceptable glycemic control (HbA1c 52 mmol/mol). Glycosuria was detected persistently during the first six months after transplantation. To achieve further improvement in glycemic control, a shift from tacrolimus to cyclosporine (CyA) was made and steroids were rapidly tapered and stopped. To minimize calcineurin inhibitors toxicity, which was revealed in the 1-year-protocol-biopsy, everolimus was introduced thereby lowering CyA through levels. Moderate hypertension was well controlled with doxazosin. Thirty months after transplantation a second graft biopsy was performed owing to renal function decline and microalbuminuria appearance. Histological analysis surprisingly showed mesangiolysis and microaneurysms; glomerular sclero-hyalinosis and basal membrane thickness and typical nodular glomerulosclerosis. C4d staining was negative and no evidence of immune deposits were detected. Donor Specific Antibodies, serum C3 and C4 levels and autoimmunity tests were negative. Retrospective analysis on donor history didn't show diabetes or insulin resistance and no diabetic lesions were found in kidney pre-implant biopsy. Conclusions: In our knowledge, this is the first report describing a very early onset of advanced diabetic glomerular lesions in a graft biopsy after PTDM. We hypothesize that additional factors such as everolimus and hypertension, may have contribute to kidney damage.