Umbilical cord mesenchymal stem cells for the treatment of autoimmune diseases: beware of cell-to-cell contact

We have read with great interest the article from Deng and colleagues1 reporting on the results of a randomised, controlled clinical trial of allogeneic umbilical cord-derived mesenchymal stem cells (UC-MSCs) for lupus nephritis. The study demonstrated that the administration of intravenous UC-MSCs does not provide additional benefit to conventional immunosuppression.

Over the last decade, increasing evidence has indicated that UC-MSCs are multipotent cells with promising applications to regenerative medicine2 and also a powerful tool to modulate the immune system. UC-MSCs can interact with most immune cell types via both cell–cell contact and secretion of soluble molecules. In this regard, the inhibition of effector T lymphocytes and the stimulation of regulatory T (Treg) cells are part of their most relevant effects.3 Therefore, several studies attempted at investigating the therapeutic potential of UC-MSC in a wide range of autoimmune diseases. Despite promising results in experimental...