A Multi-Year Analysis of Islet Transplantation Compared With Intensive Medical Therapy on Progression of Complications in Type 1 Diabetes

TLDR

The study aimed to test whether islet transplantation improves glucose control, renal function, retinopathy, and neuropathy versus intensive medical therapy in type 1 diabetes. A prospective crossover cohort of 42 patients received intensive therapy first, then 31 underwent portal‑venous islet transplantation (>12,000 islet equivalents/kg) with immunosuppression, and outcomes (HbA1c, GFR, retinopathy, nerve conduction) were monitored over ~3 years. Islet transplantation lowered HbA1c and markedly reduced retinopathy progression compared with intensive therapy, while GFR decline was less pronounced and nerve conduction remained stable over the 3‑year follow‑up.

Abstract

We hypothesized that transplantation of islets into type 1 diabetics could improve outcomes of glucose metabolism, renal function, retinopathy, and neuropathy compared with intensive medical therapy.We conducted a prospective, crossover, cohort study of intensive medical therapy (group 1) versus islet cell transplantation (group 2) in 42 patients. All were enrolled in group 1 then 31 crossed over with group 2 when islet donation became available. Transplantation was performed by portal venous embolization of more than 12,000 islet equivalents/kg body weight under cover of immunosuppression with antithymocyte globulin, tacrolimus, and mycophenolate. Outcome measures were HbA1c, change in glomerular filtration rate (GFR), progression of retinopathy, and change in nerve conduction velocity. This report details interim analysis of outcomes after 34+/-18 months (group 1) and 38+/-18 months (group 2).HbA1c (%) in group 1 was 7.5+/-0.9 versus 6.6+/-0.7 in group 2 (P<0.01). GFR (mL/min/month) declined in both groups (group 1 -0.45+/-0.7 vs. group 2 -0.12+/-0.7, P=0.1). Slope of the GFR decline in group 1 was significantly more than 0. Retinopathy progressed in 10 of 82 eyes in group 1 versus 0 of 51 in group 2 (P<0.01). Nerve conduction velocity (m/sec) remained stable in group 1 (47.8+/-5 to 47.1+/-5 m/sec) and group 2 (47.2+/-4.5 to 47.7+/-3.5).Islet transplantation yields improved HbA1c and less progression of retinopathy compared with intensive medical therapy during 3 years follow-up.