Umbilical Cord Mesenchymal Stem Cell Transfusion Ameliorated Hyperglycemia in Patients with Type 2 Diabetes Mellitus

Background: Type 2 diabetes mellitus (T2DM) is a serious threat to human health and remains incurable. Insulin deficiency seems to be attributed to the progressive failure of pancreatic islet beta-cells and immune cells such as T cells mediated cytotoxicity may be involved in the loss of pancreatic islet beta-cells in T2DM. Targeting on the immune system to maintain functional activity of pancreatic islet beta-cells could be an attractive way to treat T2DM. Mesenchymal stem cells (MSCs) exert potent capacity of immunomodulation. MSCs have been successfully applied for the treatment of several types of autoimmune diseases. So, the aim of this study is to evaluate the safety and potential therapeutic effects of UMSC on T2DM. Methods: UMSCs were separated, expanded, and identified on the basis of the previous description. 18 patients of T2DM were recruited according to our experimental protocol. UMSC was intravenously transfused three times. All patients were followed up in the first, third, and sixth month. Age, gender, diabetes duration and medications as well as weight, height, and BMI were recorded. Fasting plasma glucose (FPG), postprandial blood glucose (PBG), HbA1c, C-peptide, and subsets of T cells were measured. All adverse reactions were carefully documented. Effective criteria were made and data was analyzed using SPSS 19.0 software. Results: UMSCs were successful obtained. Baseline clinical characteristics between the efficacy and inefficacy groups were not statistically different (p > 0.05). FBG and PBG of the patients in efficacy group were significantly reduced (p < 0.05) after UMSC transfusion. Plasma C-peptide levels and regulatory T (Treg) cell number in the efficacy group were numerically higher after UMSC transfusion; however, the difference of both parameters did not reach significance (p > 0.05). During the treatment course only 4 out of 18 patients (22.2%) had slight transient fever. Up to 6 months after UMSC transfusion, all patients continued to have a feeling of well-being and were physically more active. Conclusions: UMSC transfusion is safe and well tolerated, effectively alleviates blood glucose, and increases the generation of C-peptide levels and Tregs in a subgroup of T2DM patients. This pilot study provides fundamental data for further study of UMSC transfusion on control of blood glucose as well as morbidity of T2DM in a larger cohort.