Inclusion Criteria:

• Type 1 Diabetes
• Metabolic lability/instability characterized by hypoglycemia or ketoacidosis(>2 hospital admissions in the previous year), erratic glucose profiles(MAGE >120mg/dL), or disruption in lifestyle(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 diabetes care team.

• Progressive secondary complications as defined by

  • a new diagnosis by an opthalmologist of proliferative retinopathy or clinically significant macular edema or therapy with photocoagulation during the last year; or
  • urinary albumin excretion rate >300mg/day but proteinuria <3g/day; or
  • symptomatic autonomic neuropathy (as defined by postural hypotension in the setting of euvolemia, gastroparesis or diarrhea attributed to diabetic neuropathy, or neuropathic bladder as diagnosed by an urologist)

Exclusion Criteria:

• Patient weighs more than 80kg or body mass index BMI>28
• Patient's insulin requirement is >55 Units/day.
• Current use of immunosuppressive agents.
• History of malignancy within 10 years (except for adequately treated basal or squamos cell CA of the skin).
• Active peptic ulcer disease.
• Severe umremitting diarrhea or other GI disorders potentially interfering with the ability to absorb oral medications.
• Untreated proliferative retinopathy.
• Pregnancy or breastfeeding.
• Female subjects not post-menopausal or surgically sterile, or not using an acceptable method or contraception.
• Active infections.
• Major ongoing psychiatric illness.
• Ongoing substance abuse, drug or alcohol; or recent history of noncompliance.
• Portal hypertension or history of significant liver disease.
• Lymphopenia (<1000/ul) or leukopenia (<3000 total leukocytes/ul) or an absolute CD4 count <500/ul.
• Presence or history of panel-reactive anti-HLA antibody >20%.
• Evidence of acute EBV infection (IgM>IgG) OR no serologic evidence of previous exposure to EBV (IgG>IgM).
• Serologic evidence of infection with HIV or HbsAg or HCV Ab positive.
• Creatinine clearance <60ml/min/m2.
• Positive lymphocytoxic cross-match using donor lymphocytes and serum