Author Affiliations: Schuster Transplant Research Center, Brigham and Women's Hospital, Boston, Massachusetts (firstname.lastname@example.org).
To the Editor: Dr Tan and colleagues reported a randomized controlled trial using autologous mesenchymal stem cells (MSCs) as induction therapy in living-related kidney transplants.1 We would like clarification of some technical aspects regarding the preparation of the MSCs, safety measures, and infusion site because of some concerns about potential unexpected complications of MSC therapy in a phase 1 clinical trial with MSCs in kidney transplantation.2 Specifically, the authors should describe what type of serum was used in cultures, the method applied for detachment of MSCs from the culture plate, and if MSC markers were checked prior to every infusion. Based on recent animal data reporting the appearance of visceral tumors following MSC therapy,3 it would also be important to document cancer complications in the first year after kidney transplantation. In addition, the site of infusion of MSCs (peripheral vein vs renal artery) might have an important role in the outcome because some studies suggest that most MSCs get lodged in pulmonary capillaries when injected into peripheral veins.4
Riella LV, Chandraker A. Stem Cell Therapy in Kidney Transplantation. JAMA. 2012;308(2):130-131. doi:10.1001/jama.2012.6370