Haematopoietic stem cell transplantation for severe autoimmune diseases: new perspectives.

Autoimmune diseases affect 5% of the population. Autoimmunity, inflammation and tissue damage feature in this heterogeneous group of disorders. The potential of haematopoietic stem cell transplantation (HSCT) for the treatment of autoimmune diseases was originally supported by animal experiments (reviewed in van Bekkum [1]) together with occasional remission of autoimmune diseases in patients undergoing HSCT for haematological disorders. Improved safety of both autologous and allogeneic HSCT has allowed the use of such procedures as an experimental treatment for severe autoimmune disease resistant to conventional treatments. One of the first challenges in this context was to bring together haematologists and specialists in many other fields including nephrology, rheumatology, paediatrics, internal medicine and neurology. From now on, data on almost 800 procedures are collated in international databases [2]. Although phase III trials are in progress, the main conclusion that can be drawn from this experience is that HSCT is certainly not effective in all patients whatever the type of autoimmune disease, and has so far not been proved to be of long-term benefit at the population level. In this comment, we will discuss the potential explanations for such a limitation and suggest some innovations that might improve clinical outcome. Clinical experience