Islet Cell Transplantation in Patients With Type I Diabetes With Previous Kidney Transplantation

Inclusion Criteria: * Type 1 diabetes mellitus. Documentation of negative basal and stimulated C-peptide and diagnosis of diabetes for at least 5 years. * Recipient of renal transplant with good function (creatinine clearance \>/=60 ml/min) * Stable immunosuppression consisting of any combination of sirolimus, tacrolimus for at least 6 months, without major complications * Ability to give informed consent. * Age greater than or equal to 18 years or less than or equal to 65 years * No evidence of liver disease (liver enzymes \< twice the upper limit of normal) Exclusion Criteria: * Age below 18 years and above 65 years * Significant cardiovascular disease, including non-correctable coronary artery disease and/or recent myocardial infarction(within last 12 months); extensive peripheral vascular disease not correctable by surgery, unstable angina * Untreated proliferative retinopathy. * Recent Cerebrovascular accident (within last 12 months) * Recent unresolved acute infection, or chronic infection, including tuberculosis, HIV, HBV, HCV, CMV or positive skin test for TB * Any history of malignancy, except squamous or basal skin cancer or in situ cancer of the cervix. * History of non-compliance, or inability to demonstrate capacity to comply with strict blood glycemic control and insulin pump therapy. * Psychiatric illness that is untreated, or likely to interfere significantly with transplantation despite treatment. * Pregnant women, women intending future pregnancy, women of reproductive potential who are unable or unwilling to follow effective contraceptive measures for the duration of immunosuppressive therapy * Fasting C-peptide \> 0.2 ng/ml * Creatinine \> 25mg/l * Alkaline phosphatase, total bilirubin, Alanine Aminotransferase (ALT)or Aspartate Aminotransferase (AST) \> twice the upper limit of normal * Significant liver disease (elevation of liver enzymes \> twice the upper limit of normal for each of ALT and AST, liver masses including portal vein thrombosis, evidence of portal hypertension, or significant, untreated gallbladder disease (i.e., gallstones).