The effect of medical therapy and islet cell transplantation on diabetic nephropathy: An interim report

Background. The effect of islet cell transplantation (ICT) on renal function in type 1 diabetes is uncertain and some recent studies report a significant decline in estimated glomerular filtration rate (GFR) and worsening of albuminuria. Methods. We are conducting a prospective crossover study comparing medical treatment with islet transplantation on the progression of diabetic complications, including renal function. The primary endpoint is change in GFR measured by Tc-99m-diethylenetriaminepentaacetate with secondary endpoints including estimated GFR and albumin excretion. Results. We have followed 21 patients after islet transplantation a median of 29 months (range 13-45) and compared their results with medically treated patients followed a median 29.5 months (range 13-56). There is no difference in the rate of decline in measured GFR between medically treated patients (-0.35 +/- 0.89; 95% CI: -0.57 to -0.13 mL/min/month/1.73 m(2)) and those after ICT (-0.31 +/- 1.18; 95% CI: -0.61 to -0.01) and neither is significantly different from that expected for the general population. The rate of decline in our estimated GFR results is lower than that reported in other studies and we did not find any worsening of albuminuria. Conclusions. We do not find evidence of worsening of renal function after islet transplantation compared with medically treated patients.