Hematopoietic stem cell transplantation in rheumatic diseases other than systemic sclerosis and systemic lupus erythematosus.

Hematopoietic stem cells (HSC) are increasingly available as an alternative to whole marrow aspirate for bone marrow transplantation (BMT). They may be derived from an HLA matched individual (allogeneic) or from the patient (autologous). Allogeneic BMT is associated with a 15 to 35% mortality, largely due to graft versus host disease. Autologous HSC are used to rescue the patient after severe immunosuppression, and the transplant related mortality is 3 to 5%. The opportunity to ablate severe autoimmune disease with increased safety is particularly attractive for necrotizing vasculitides, polymyositis/dermatomyositis, primary Sjögren's syndrome, systemic juvenile arthritis, relapsing polychondritis, and Behçet's disease, where correct selection of cases would ensure an acceptable benefit/risk ratio. Rheumatoid arthritis (RA), psoriasis associated arthritis (PsA) and some non-rheumatic diseases such as inflammatory bowel disease (IBD), multiple sclerosis, and type 1 diabetes mellitus may also be candidates, but careful selection of patients with a poor prognosis is necessary. There are allogeneic BMT data from patients with aplastic anemia or leukemia and concurrent RA, PsA, and IBD and also autologous HSC BMT data from animal models to support the concept of cure. Patient studies should proceed using recently published protocol guidelines and centralized data collection.