CAMPATH Campath-1H is a humanized fusion protein that is directed to CD52 antigen that is expressed on all lymphocytes, monocytes and macrophages. It has very potent immunosuppressive property and is effective for prevention of graft-versus-host disease. 30 mg/day of CAMPATH will be given intravenously over 2 hours on days -4, -3 and -2. The most commonly reported adverse reactions are infusion reactions fever, chills, hypotension, urticaria, nausea, rash, tachycardia, dyspnea), cytopenias (neutropenia, lymphopenia, thrombocytopenia, anemia), and infections (CMV viremia, CMV infection, other infections). In clinical trials, the frequency of infusion reactions was highest in the first week of treatment. Other commonly reported adverse reactions include vomiting, abdominal pain, insomnia and anxiety. The most commonly reported serious adverse reactions are cytopenias, infusion reactions, and immunosuppression/infections. About 30 minutes before the patient gets Campath, he/she will be given other medications (such as acetaminophen or diphenhydramine, given orally, not IV) to help reduce side effects.