Non-myeloablative Allogeneic Hematopoietic Stem Cell Transplantation (NST) for Patients With Refractory Crohn's Disease

PBSC will be mobilized with G-CSF 10 mcg/kg/day (dose may be adjusted down to 5 mcg/kg/day by PI for toxicity, e.g. flu-like symptoms) with stem cell collection beginning on day 4 or 5. Leukapheresis may be repeated up to three consecutive days. Cyclophosphamide 60 mg/kg/day x 2 days will be given IV over 1 hour in 500 cc of normal saline. Dosage should be based on the lesser of adjusted body weight or actual weight. Mesna 50mg/day x 2 days will be given IV over 24 hours CAMPATH-1H 30mg/day x 2 days (no dose adjustment) will be given IV over 2 hours in 100 cc of normal saline. Premedication with Solumedrol 1g IV, Acetaminophen 650mg \& benadryl 50mg PO/IV will be given 30-60min before infusion. Also while on CAMPATH, Chlorphenamine 4 mg PO TID, Singular 10 mg PO daily, Pepcid 40 mg PO BID and Claritin 10 mg PO daily will be given, adjusted as needed. These medications can be repeated or changed as needed. Fludarabine 30mg/m2 daily for 3 days (no dose adjustment) will be given IV over 30 minutes in 100 cc normal saline. Hydration approximately 150ml/hr should begin 2 hours before cyclophosphamide and continue until 24 hours after the last cyclophosphamide dose. Daily weights will be obtained. Amount of fluid can be modified based on patient's fluid status. G-CSF will be continued until absolute neutrophil count reaches at least 1,000/ul. Cyclosporin will be started on day -2 at 200 mg po BID and adjusted by HPLC levels to between 150 - 250 or by toxicity (e.g., tremor, renal insufficiency, TTP, etc.). CSA will be continued for 30 days unless stopped for toxicity or needed to maintain donor engraftment. Cyclosporine and MMF guidelines dosage and duration can be modified according to investigators discretion based on side effects, renal function, CBC and GVHD status.