Improving outcomes in clinical islet transplantation: 1999-2010

OBJECTIVEdTo describe trends of primary efficacy and safety outcomes of islet transplantationin type 1 diabetes recipients with severe hypoglycemia from the Collaborative Islet TransplantRegistry (CITR) from 1999 to 2010.RESEARCH DESIGN AND METHODSdA total of 677 islet transplant-alone or isletafter-kidney recipients with type 1 diabetes in the CITR were analyzed for five primary efficacyoutcomes 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.RESULTSdInsulin 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 themost recent era (P,0.001). Reduction ofHbA1c and resolution of severe hypoglycemia exhibited enduring long-term effects. Fasting bloodglucose stabilization also showed improvements in the most recent era. There were also modestreductions in the occurrence of adverse events. The islet reinfusion rate was lower: 48% by 1 yearin 2007–2010 vs. 60–65% in 1999–2006 (P , 0.01). Recipients that ever achieved insulinindependenceexperienced longer duration of islet graft function (P , 0.001).CONCLUSIONSdThe CITR shows improvement in primary efficacy and safety outcomes ofislet transplantation in recipients who received transplants in 2007–2010 compared with thosein 1999–2006, with fewer islet infusions and adverse events per recipient.