Secondary efficacy endpoints: At 75±7, 365 ± 14 ,and 730 ± 14 days following the islet transplant(s): the percent reduction in insulin requirements; HbA1c; Mean Amplitude of Glycemic Excursions (MAGE); Lability Index (LI); Ryan hypoglycemia severity (HYPO) score; Clarke score; number of severe hypoglycemic episodes; basal (fasting) and 90-min glucose and c-peptide derived from the mixed-meal tolerance test (MMTT); beta-score; C-peptide creatinine ratio; acute insulin response to glucose (AIRglu), insulin sensitivity, and disposition index derived from the insulin-modified frequently-sampled intravenous glucose tolerance (FSIGT) test; glucose variability and hypoglycemia duration derived from the continuous glucose monitoring system® (CGMS); and Quality of life (QOL) measures: EuroQol five dimensions questionnaire (EQ-5D), Hypoglycemia Fear Survey (HFS), SF-36v2, Diabetes Distress scale).