Stem cell therapies

Since the start of the international project in 1997, over 2000 patients have received a haematopoietic stem cell transplant (HSCT), mostly autologous, as treatment for a severe autoimmune disease, with overall 85% 5-year survival and 43% progression-free survival. Around 30% of patients in all disease subgroups had a complete response, often durable despite full immune reconstitution. In many cases, e.g. systemic sclerosis, morphological improvement such as reduction of skin collagen and normalization of microvasculature was documented, beyond any predicted known effects of intense immunosuppression alone. It is hoped that the results of the three running large prospective randomized controlled trials will allow modification of the protocols to reduce the high transplant-related mortality which relates to regimen intensity, age of patient, and comorbidity. Multipotent mesenchymal stromal cells (MSC) have been recently tested in various autoimmune diseases, exploiting their immune modulating properties and apparent low acute toxicity. MSC display immune privilege in that the patient requires no immunosuppression prior to allogeneic MSC infusion. Despite encouraging many small phase I/II studies, only 2 prospective controlled trials which achieved their primary endpoints have been published.