To examine whether temporary immunosuppression with ATG, tacrolimus and MMF allows prolonged survival of beta cell allografts in type 1 diabetic patients with early chronic complications of diabetes.

Inclusion Criteria:

• type 1 insulin-dependent diabetic patients in relatively good general condition
• non-smoker
• body weight < 80 kg
• C-peptide < 0.03 nmol/l (<0.09 µg/l) 6 min. after glucagon IV (1mg) (glycemia > 180 mg/dl)
• EBV antibody positive
• cooperative and reliable patient giving informed consent by signature; the patient should be informed in sufficient detail on the content and procedure of the protocol, indicating potential risks of intervention and of immunosuppressive therapy; the patient should also be informed that withdrawal of immunosuppressive therapy in patients with persistent plasma C-peptide positivity may result in subsequent loss of ß-cell graft function; the ß cell implant should be identified as a clinical trial

Exclusion Criteria:

• history of thrombosis or pulmonary embolism
• abnormal liver function
• HLA antibodies