Background: The beneficial effects of glycemic control on both survival and function of transplanted kidneys in patients with type 1 diabetes mellitus (T1DM) and end-stage renal disease (ESRD) have been recognized.
Methods: Herein, we present the clinical outcome of a single-center pilot trial of islet after kidney (IAK) transplantation in seven patients with T1DM. The immunosuppression protocol for the kidney graft was converted to sirolimus+tacrolimus regimen 6 months before islet transplantation to exclude negative effects on kidney graft function. Primary endpoint was achievement of insulin independence after transplantation. Clinical outcome, metabolic control, severe hypoglycemia, kidney function, Quality of Life (QOL) psychometric measures, and adverse events were monitored.
Results: Seven patients showed graft function with improved metabolic control (A1c, fasting glycemia, and metabolic tests) after IAK (14,779+/-3,800 IEQ/kg). One-year insulin independence was 30% with persistent graft function in 86% (C-peptide-positive). A1c reduction was 1.95+/-0.31% from baseline (P<0.0001). No episodes of severe hypoglycemia were observed, even after resuming insulin. The direct consequence of these benefits was a significant improvement in diabetes QOL. Adverse events included procedure-related pleural effusion (n=2), cholecystitis (n=1), and additional immunosuppression-related, all resolved without sequelae. Kidney function (by estimated glomerular filtration rate) remained stable during follow-up in six of seven patients.
Conclusions: Islet transplantation represents a feasible therapeutic option for patients with T1DM bearing a stable kidney allograft. Insulin independence at 1 year is lower than what reported in islet transplant alone. Nevertheless, clear benefits in terms of optimal metabolic control and absence of severe hypoglycemia are invariably present.