Safety and efficacy of allogeneic adipose tissue-derived mesenchymal stem cells for treatment of dogs with inflammatory bowel disease: Endoscopic and histological outcomes.

Systemic administration of mesenchymal stem cells (MSCs) has been shown to be safe and efficacious in humans with Crohn's disease. The aim of this study was to evaluate the safety of an intravenous (IV) infusion of adipose tissue-derived mesenchymal stem cells (ASCs) and to assess macroscopic and histological effects in the digestive tract of dogs with inflammatory bowel disease (IBD). Eleven dogs with confirmed IBD received a single ASC infusion (2 × 10(6) cells/kg bodyweight). Full digestive endoscopic evaluation was performed pre-treatment and between 90 and 120 days post-treatment with mucosal changes being assessed using a fit-for-purpose endoscopic scale. Endoscopic biopsies from each digestive section were evaluated histologically according to the World Small Animal Veterinary Association (WSAVA) Gastrointestinal Standardization Group criteria. The pre- and post-treatment canine IBD endoscopic index (CIBDEI) and histological score (HS) were calculated and compared using the Wilcoxon test. Remission was defined as a reduction of >75% of the CIBDEI and HS compared with pre-treatment. No acute reactions to ASC infusion or side effects were reported in any dog. Significant differences between pre- and post-treatment were found in both the CIBDEI (P = 0.004) and HS (P = 0.004). Endoscopic remission occurred in 4/11 dogs with the remaining dogs showing decreased CIBDEI (44.8% to 73.3%). Histological remission was not achieved in any dog, with an average reduction of the pre-treatment HS of 27.2%. In conclusion, a single IV infusion of allogeneic ASCs improved gastrointestinal lesions as assessed macroscopically and slightly reduced gastrointestinal inflammation as evaluated by histopathology in dogs with IBD.

Safety and efficacy of allogeneic adipose tissue-derived mesenchymal stem cells for treatment of dogs with inflammatory bowel disease: Clinical and laboratory outcomes.

Mesenchymal stem cells (MSCs) have shown immunomodulatory and anti-inflammatory effects in experimental colitis, and promising clinical results have been obtained in humans with Crohn's disease and ulcerative colitis. The aim of this study was to determine the safety and feasibility of adipose tissue-derived MSC (ASC) therapy in dogs with inflammatory bowel disease (IBD). Eleven dogs with confirmed IBD received one ASC intravascular (IV) infusion (2 × 10(6) cells/kg bodyweight). The outcome measures were clinical response based on percentage reduction of the validated Clinical Inflammatory Bowel Disease Activity Index (CIBDAI) and Canine Chronic Enteropathy Clinical Activity Index (CCECAI), as well as normalisation of C-reactive protein (CRP), albumin, folate and cobalamin serum concentrations at day 42 post-treatment. The Wilcoxon test was used to compare variables before and after treatment. No acute reaction to ASC infusion and no side effects were reported during follow-up in any dog. Six weeks post-treatment, the CIBDAI and CCECAI decreased significantly and albumin, cobalamin and folate concentrations increased substantially. Differences in CRP concentrations pre- and post-treatment were not significant (P = 0.050). Clinical remission (defined by a reduction of initial CIBDAI and CCECAI >75%) occurred in 9/11 dogs at day 42. The two remaining dogs showed a partial response with reduction percentages of 69.2% and 71.4%. In conclusion, a single IV infusion of allogeneic ASCs was well tolerated and appeared to produce clinical benefits in dogs with severe IBD.

Mesenchymal stem cells regulate airway contractile tissue remodeling in murine experimental asthma.

BACKGROUND: Mesenchymal stem cells may offer therapeutic potential for asthma due to their immunomodulatory properties and host tolerability, yet prior evidence suggests that bloodborne progenitor cells may participate in airway remodeling. Here, we tested whether mesenchymal stem cells administered as anti-inflammatory therapy may favor airway remodeling and therefore be detrimental. METHODS: Adipose tissue-derived mesenchymal stem cells were retrovirally transduced to express green fluorescent protein and intravenously injected into mice with established experimental asthma induced by repeat intranasal house dust mite extract. Controls were house dust mite-instilled animals receiving intravenous vehicle or phosphate-buffered saline-instilled animals receiving mesenchymal stem cells. Data on lung function, airway inflammation, and remodeling were collected at 72 h after injection or after 2 weeks of additional intranasal challenge. RESULTS: The mesenchymal stem cells homed to the lungs and rapidly downregulated airway inflammation in association with raised T-helper-1 lung cytokines, but such effect declined under sustained allergen challenge despite a persistent presence of mesenchymal stem cells. Conversely, airway hyperresponsiveness and contractile tissue underwent a late reduction regardless of continuous pathogenic stimuli and inflammatory rebound. Tracking of green fluorescent protein did not show mesenchymal stem cell integration or differentiation in airway wall tissues. CONCLUSIONS: Therapeutic mesenchymal stem cell infusion in murine experimental asthma is free of unwanted pro-remodeling effects and ameliorates airway hyper-responsiveness and contractile tissue remodeling. These outcomes support furthering the development of mesenchymal stem cell-based asthma therapies, although caution and solid preclinical data building are warranted.