Inclusion Criteria:

• Patient fully informed, signed dated IRB-approved informed consent form obtained directly by the P.I., Co-P.I., or Res. Nurse, and willing to follow study procedures for the duration of study (3 yrs).
• Recipient: a hematocrit of ≥ 33%, and a hemoglobin of ≥ 11.0 g/dL.
• Recipient: normal thyroid function (TSH, T4, Free T4).
• Weight > 40 kg.
• Primary renal allograft: living related (HLA-identical donor-recipient sibling pairs)
• Negative B-cell and T-cell cytotoxic and flow cytometry cross-match, and a low (≤ 10%) PRA using cytotoxicity and flow cytometry.
• Women of childbearing potential: negative qualitative serum pregnancy test.
• Patients studied equivalently as available for transplant using criteria, w/out regard to gender, race, or ethnicity.
• Normal echocardiogram w/ ejection fraction >50%.
• Full course vaccination for hep. B (Recombivax hepatitis B vaccine 40 μg) completed at least 6 weeks pre-transplant or naturally acquired immunity.
• Male participants w/ reproductive potential agree to use approved methods of birth control during treatment w/ Campath-1H and for minimum of 6 months following last dose. Female participants of childbearing potential agree to use approved methods of birth control for duration of participation in study.
• Patient agrees to follow-up every 2 months after year 3, up to 10 years.

Exclusion Criteria:

• Patient previously received/receiving transplant other than kidney.
• Patient receiving ABO incompatible donor kidney.
• Recipient/donor is ELISA positive for human immunodeficiency virus (HIV), antibody positive for hep. C, or surface antigen positive for hep. B.
• Recipient/donor is positive for TB (or under treatment for suspected TB), or previous exposure to TB (positive Mantoux) and not undergone an accepted treatment.
• Patient has current malignancy or history of malignancy (within past 5 years), except non-metastatic basal or squa¬mous cell carcinoma of the skin, or carcinoma in situ of the cervix that has been treated successfully.
• Patients w/ significant liver disease, defined as having during past 28 days continuously elevated AST (SGOT) and/or ALT (SGPT) levels greater than 3 times the upper value of the normal range at this center.
• Patient has uncontrolled concomitant infections and/or severe diarrhea, vomiting, active upper gastro-intestinal tract malabsorption or active peptic ulcer or other unstable medical condition that could interfere w/ study objectives.
• Patient currently receiving investigational drug or received an investigational drug within 30 days pre-transplant.
• Patient currently receiving immunosuppressive agent.
• In investigator's judgment, anticipated that patient unable to take medications orally or via nasogastric tube by morning of second day (i.e., skin closure).
• Concurrent use of warfarin, fluvastatin, astemizole, pimozide, cisapride, terfenadine, or ketoconazole.
• Patient hypersensitivity to tacrolimus, Campath-1H, Thymoglobulin, daclizumab (Zenapax®), sirolimus, MMF or corticosteroids.
• Patient pregnant or lactating.
• Patients w/ screening/baseline total white blood cell count <4000/mm3; platelet count <100,000/mm3; fasting triglycerides >400 mg/dl (>4.6 mmol/L); fasting total cholesterol >300 mg/dl (>7.8 mmol/L); fasting HDL-cholesterol <30 mg/dl; fasting LDL-cholesterol >200 mg/dl.
• Patient unlikely to comply w/ visits.
• Patient w/ any form of substance abuse, psychiatric disorder or condition that, in investigator's opinion, may invalidate communication.
• Expected that tacrolimus cannot be instituted for over 5 days post-operatively.
• Patients w/ PRA value >10% any time pre-enrollment.
• Patients w/ Graves disease, unless previously treated w/ radioiodine ablative therapy.
• CMV/EBV negative recipients of CMV/EBV positive donor.
• History of ITP or TTP