An outsider's view on SLE research

Induction of tolerance in autoimmune diseases by hematopoietic stem cell transplantation: getting closer to a cure?

Hematopoietic stem cells (HSCs) are the earliest cells of the immune system, giving rise to B and T lymphocytes, monocytes, tissue macrophages, and dendritic cells. In animal models, adoptive transfer of HSCs, depending on circumstances, may cause, prevent, or cure autoimmune diseases. Clinical trials have reported early remission of otherwise refractory autoimmune disorders after either autologous or allogeneic hematopoietic stem cell transplantation (HSCT). By percentage of transplantations performed, autoimmune diseases are the most rapidly expanding indication for stem cell transplantation. Although numerous editorials or commentaries have been previously published, no prior review has focused on the immunology of transplantation tolerance or development of phase 3 autoimmune HSCT trials. Results from current trials suggest that mobilization of HSCs, conditioning regimen, eligibility and exclusion criteria, toxicity, outcome, source of stem cells, and posttransplantation follow-up need to be disease specific. HSCT-induced remission of an autoimmune disease allows for a prospective analysis of events involved in immune tolerance not available in cross-sectional studies.

New horizons in the treatment of autoimmune diseases: immunoablation and stem cell transplantation

The prevalence of autoimmune diseases (ADs) in Western countries is estimated to be from 3-7%, and the treatment of severe, relapsing/refractory cases is still not satisfactory. The concept of utilizing intense immunosuppression followed by allogeneic or even autologous hemolymphopoietic stem cells (HSCs) to treat AD is based on encouraging results in experimental animals and from serendipitous cases of patients with both ADs and malignancies who were allotransplanted for the latter. However, rare unexpected relapses despite donor immune engraftment have been reported following HSC transplantation for AD. Autologous transplantation is a more feasible procedure with lower toxicity than allogeneic transplantation. This article analyzes the experimental basis for stem cell transplantation in AD and discusses the most important clinical results of both allogeneic and autologous HSC transplants.