Glomerular ultrastructure in kidneys transplanted simultaneously with a segmental pancreas to patients with type 1 diabetes

BACKGROUND.: Pancreas transplantation has been reported to prevent developmentand progression of diabetic glomerulopathy. STUDY DESIGN.: Kidneys transplanted to type 1 diabetic patients were investigatedfor signs of diabetic glomerulopathy. Biopsies were obtainedfrom 11 patients 2–4 years after simultaneous pancreasand kidney transplantation and from six patients 2–6 yearsafter kidney transplantation alone. During follow-up, glycaemiccontrol was monitored as glycated haemoglobin and, in the pancreastransplant patients, as i.v. glucose tolerance. RESULTS.: Measures of glycaemic control were consistently normal in onlytwo pancreas transplant patients. Four had mean k values <1.0.In kidney biopsies from the pancreas transplant patients, thicknessof the glomerular basement membrane was 395 (0.13) nm (mean,coefficient of variation), which is higher than normal (324(0.13) nm, P=0.01) and not different from diabetic patientswith kidney transplants alone, 418 (0.15) nm. The mean calculatedannual increase in thickness did not differ between patientswith and without a pancreas transplant, 26 (0.77) versus 29(0.54) nm/year. Estimates of the mesangium and mesangial matrixwere in the normal range in both groups while the interstitialvolume fraction was increased and to a similar extent. CONCLUSION.: The increase in thickness of the glomerular basement membranein kidneys transplanted simultaneously with a segmental pancreasis probably an expression of diabetic glomerulopathy causedby the modest impairment in glucose metabolism present in mostpatients.