Pancreatic Islet Transplantation Into the Gastric Submucosa

Inclusion Criteria: Key Inclusion Criteria: 1. Primary islet allotransplant 2. Type I diabetes mellitus for a minimum of 5 years 3. One or more of the following signs or symptoms despite intensive efforts made in close cooperation with their diabetic care team: * Metabolic lability/instability characterized by hypoglycemia or ketoacidosis (\>2 hospital admissions in the previous year), erratic glucose profiles (MAGE\>120 mg/dL), or disruption in lifestyle of danger to life, self or others * Reduced awareness of hypoglycemia or \>1 episode in the last 1.5 years of severe hypoglycemia * Persistently poor glucose control (as defined by HgbA1c\>10% at the end of six months of Intensive management efforts with the diabetes care team) * Progressive secondary complications as defined by (i) a new proliferative retinopathy or clinically significant macular edema or therapy with photocoagulation during the last year; or (ii) symptomatic autonomic neuropathy (as defined by postural hypotension or neuropathic bladder) 4. Age 18 and older 5. Patients who have a renal transplant must have received their transplant at least 3 months previously and must have stable renal function (see exclusion criteria below) 6. Must be able to give written informed consent Exclusion Criteria: Key Exclusion Criteria: 1. Lymphopenia (\<1000/µL) or leukopenia ( \<3000 total leukocytes/µL) 2. Presence of panel-reactive anti-HLA antibody \>20% 3. Positive lymphocytotoxic cross-match using donor lymphocytes and serum 4. Evidence of acute EBV infection (IgM\>IgG) OR no serologic evidence of previous exposure to EBV (IgG\>IgM) 5. Calculated or measured GFR \< 50 ml/min/m2 in patients without a renal transplant. 6. Calculated or measured GFR \< 40 ml/min/m2 in patients with a renal transplant. 7. Portal hypertension or history of significant liver disease 8. History of malignancy within 10 years (except for treated basal or squamous cell CA of the skin) 9. Active peptic ulcer disease or other gastric mucosal abnormalities as identified on screening endoscopy 10. Severe unremitting diarrhea or other GI disorders potentially interfering with the ability to absorb oral medications 11. Untreated proliferative retinopathy 12. Pregnancy or breastfeeding 13. Female subjects not post-menopausal or surgically sterile who are sexually active but not using an acceptable method of contraception 14. Active infections 15. Serologic evidence of infection with HIV, or HbsAg or HCV Ab positive 16. Major ongoing psychiatric illness 17. Ongoing substance abuse, drug or alcohol; or recent history of noncompliance 18. Any condition that in the opinion of the Principal Investigator does not allow safe participation in the study \-