Cyclophosphamide and rATG With Hematopoietic Stem Cell Support in Systemic Scleroderma

To evaluate the efficacy of two treatment modalities: pulse cyclophosphamide versus high dose cyclophosphamide and anti-thymocyte globulin (ATG) rescued with autologous peripheral blood stem cell transplantation (PBSCT). The primary endpoints to be considered in this study are: I)Time to Treatment Failure -Treatment failure will not occur until a minimum of 12 months after enrollment at which time failure is defined as: 1. Failure of skin score (if \> 14 on enrollment) to improve or increase in skin score by a 25% above lowest post treatment value and must be documented on 2 occasion 6 months apart 2. Deterioration in diffusing capacity of the lung for carbon monoxide (DLCO), diffusing capacity divided by the alveolar volume (DLCO/VA) or forced vital capacity (FVC) by 10% below enrollment level or 10% below best post treatment value, due to systemic sclerosis, and documented on 2 occasion 6 months apart 3. Renal failure due to systemic sclerosis and defined as chronic dialysis for more than 12 months 4. Gastrointestinal failure due to systemic sclerosis and defined as initiation of total parenteral nutrition (TPN) for more than 12 months II) Disease improvement defined by at least 25% improvement in skin score (Rodnan), or 10% improvement in pulmonary function tests (DLCO, DLCO/VA, or FVC), or in cardiac tests \[pulmonary artery (PA) systolic pressure by right heart cath) that persists \> 6 months or ability to wean off TPN