Steady progress in stem cell therapy for non-malignant disease

Modest benefits are being obtained from stem cell therapy in a number of autoimmune and cardiovascular diseases, complementing the progress that has been achieved in malignant disorders, according to a recent review. The review evaluated 26 substantial trials involving 854 patients treated with blood-derived or marrow-derived stem cells for autoimmune diseases such as multiple sclerosis, Crohn’s disease, systemic sclerosis, vasculitis, type 1 diabetes and rheumatoid arthritis. Treatment mortality was less than 1% for regimens that did not depend on myeloablation, but as high as 13% when intense myeloablation was used. “While all trials performing during the inflammatory stage of autoimmune disease suggested that transplantation may have a potent disease-remitting effect, remission duration remains unclear, and no randomised trials have been published,” it said. Autologous stem cells were probably not a ‘cure’ for autoimmune diseases but appeared to be a potentially useful approach to ameliorate disease activity, the review concluded. It also evaluated reports on 1,002 patients with acute myocardial infarction and 493 with chronic coronary artery disease, as well as three meta-analyses. The trials suggested a modest improvement in cardiac function in those with coronary artery disease. The benefits of stem cell therapy were more difficult to understand in cardiovascular than autoimmune disease. It had been suggested that stem cells included endothelial progenitors which improved the formation of new blood vessels. However, it was now thought that a sufficient load of stem cells could have a paracrine effect on a large number of other cells through a “cell-help-cell” mechanism. More research was needed to determine the most appropriate cell type, dose, method and timing of stem cells for treatment of cardiovascular diseases. Stem cell therapy had developed rapidly and generated excitement and promise as well as confusion and at times contradictory results in the lay and scientific media. It was important to recognise the progress so far and the scope for further advances, as well as the challenges and controversies. Reference...