Glomerular volume in kidneys transplanted into diabetic and non-diabetic patients

Biopsies taken at the time of renal transplantation in 12 non-diabetic and 23 diabetic patients were studied by quantitative light- and electron-microscopy. Repeat biopsies were taken at 6 months and/or after 2-3 years in patients who had acceptable graft function. All patients except two received cyclosporin as part of the immunosuppression. Glomerular volume was significantly increased, + 36(95% CI +6 to +65) % (p = 0.03), in the diabetic patients at 6 months which differed from the change of -20 (-50 to +10) % in the non-diabetic patients (p = 0.03). After 2-3 years glomerular volume was equal to the baseline value in the diabetic patients, while the change from baseline in the non-diabetic patients was -21 (-42 to -1) %. Substantial glomerular occlusion was seen in only three diabetic patients after 2-3 years. Total structural volumes per glomerulus in the 2-3-year biopsies showed an increase in basement membrane material of 0.09 x 10(6) microns 3 in the diabetic patients, significantly different from the change in non-diabetic patients (-0.10 x 10(6) microns 3, p = 0.003). No correlation was obtained between the 6-month increase in glomerular volume and the development of diabetic glomerulopathy at 2-3 years. The fact that glomerular hypertrophy was not present in the entire series may be due to the cyclosporin and to rejection. Nevertheless the diabetic group did show an early hypertrophy which did not seem to play a major role in the ensuing development of diabetic glomerulopathy.