Intensive immunosuppression with high dose cyclophosphamide but without stem cell rescue for severe autoimmunity: advantages and disadvantages.

Hematopoietic stem cell transplantation (HSCT) for the treatment of severe autoimmune disorders continues to show great promise. The morbidity and mortality of the approach is relatively low and clinical benefit has been demonstrated in many, but not all patients. Furthermore, relapse following HSCT is not uncommon. Most centers now prefer nonmyeloablative conditioning regimens using high dose cyclophosphamide prior to SCT; however, emerging data show that high dose cylophosphamide can be administered safely without the need for HSCT. Eliminating the use of HSCT after high dose cyclophosphamide shortens the duration of the procedure by several weeks, markedly reduces the cost of the procedure and eliminates the potential of reinfusing autoreactive lymphoctes with the autograft.