• Male and female subjects age 18 to 68 years.

• Subjects who are able to provide written informed consent and to comply with the procedures of the study protocol.

• Clinical history compatible with T1D with disease onset \< 40 years of age and insulin-dependence for \> 5 years at the time of enrollment, and a sum of subject age and insulin dependent diabetes duration of \> 28.

• Absent stimulated c-peptide (\< 0.3 ng/mL) in response to a MMTT \[Boost® 6 mL/kg body weight (BW) to a maximum of 360 mL; another product with equivalent caloric and nutrient content may be substituted for Boost®\] measured at 60 and 90 min after start of consumption.

• Subjects who are \> or at 3 months post-renal transplant who are taking appropriate calcineurin inhibitor (CNI) based maintenance immunosuppression (\[tacrolimus alone or in conjunction with sirolimus, mycophenolate mofetil, myfortic, or azathioprine; or cyclosporine in conjunction with sirolimus, mycophenolate mofetil, or myfortic\] ± Prednisone \< 10 mg/day)or subject will receive islets transplant within 72hours after kidney transplantation (islets and kidney are from the same donor)

• Stable renal function as defined by a creatinine of no more than one third greater than the average creatinine determination performed in the 3 previous months prior to islet transplantation, until rejection, obstruction or infection is ruled out.