Sepsis--frequently called 'blood poisoning'--is the number one cause of death in critically ill patients and is caused by overwhelming infection. Currently, sepsis remains without an effective specific treatment strategy; however, new findings out of UHN, St. Michael's Hospital and the University of Ottawa harness the immune-regulating power of stem cells to improve clinical outcome in this devastating disease.

Co-led by TGRI's Dr. W. Conrad Liles and the University of Ottawa's Dr. Duncan Stewart, a series of molecular investigations found that administering mesenchymal stem (stromal) cells (MSCs)--stem cells from the bone marrow--to mice with sepsis (and receiving appropriate antimicrobial therapy) significantly reduced mortality in comparison to mice who did not receive MSC treatment. Studies also went on to show that MSCs significantly reduced the level of proteins that are responsible for promoting inflammation, which is a critical component of sepsis.

"MSCs were able to up-regulate or 'turn on' genes involved in positive immune action, specifically killing invading bacteria," explains Dr. Liles. "Our studies show that, by reducing inflammation and promoting the eradication of bacteria, MSC therapy may be an effective tool, in partnership with current therapies, to reduce sepsis-related morbidity and death. This study demonstrates the potential for therapeutic use of MSCs for sepsis and provides the basis for launching a clinical trial in patients with sepsis."

Mei SH, Haitsma JJ, Dos Santos CC, Deng Y, Lai PF, Slutsky AS, Liles WC, Stewart DJ. Am J Respir Crit Care Med. 2010 Jun 17. [Epub ahead of print]. [Pubmed abstract]. Research supported by the Canadian Institutes of Health Research, Northern Therapeutics, NSERC Doctoral Canada Graduate Scholarship and Ontario Graduate Scholarship, the Weston Foundation, the McLaughlin Centre for Molecular Medicine and the Canada Research Chairs Program.