Improvement in Outcomes of Clinical Islet Transplantation: 1999–2010

TLDR

The study aims to describe trends in primary efficacy and safety outcomes of islet transplantation for type 1 diabetes patients with severe hypoglycemia using CITR data from 1999 to 2010. The authors analyzed 677 CITR recipients over 1999–2010, comparing five primary efficacy outcomes and safety across early, mid, and recent transplant eras with up to five years of follow‑up. Insulin independence rose from 27 % to 44 % over the study period, with longer C‑peptide retention, sustained HbA1c reduction, improved fasting glucose, fewer adverse events, lower reinfusion rates, and longer graft function among insulin‑independent patients, indicating overall improved efficacy and safety of islet transplantation in the most recent era.

Abstract

OBJECTIVE To describe trends of primary efficacy and safety outcomes of islet transplantation in type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet Transplant Registry (CITR) from 1999 to 2010. RESEARCH DESIGN AND METHODS A total of 677 islet transplant-alone or islet-after-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacy outcomes and overall safety to identify any differences by early (1999–2002), mid (2003–2006), or recent (2007–2010) transplant era based on annual follow-up to 5 years. RESULTS Insulin independence at 3 years after transplant improved from 27% in the early era (1999–2002, n = 214) to 37% in the mid (2003–2006, n = 255) and to 44% in the most recent era (2007–2010, n = 208; P = 0.006 for years-by-era; P = 0.01 for era alone). C-peptide ≥0.3 ng/mL, indicative of islet graft function, was retained longer in the most recent era (P < 0.001). Reduction of HbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting blood glucose stabilization also showed improvements in the most recent era. There were also modest reductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 year in 2007–2010 vs. 60–65% in 1999–2006 (P < 0.01). Recipients that ever achieved insulin-independence experienced longer duration of islet graft function (P < 0.001). CONCLUSIONS The CITR shows improvement in primary efficacy and safety outcomes of islet transplantation in recipients who received transplants in 2007–2010 compared with those in 1999–2006, with fewer islet infusions and adverse events per recipient.