To explore the efficacy and safety of non-myeloablative autologous peripheral hematopoietic stem cell (HSC) and single allogeneic umbilical cord mesenchymal stem cell (MSC) transplantation in the treatment of patients with type 1 diabetes mellitus (T1DM).

This was a retrospective case-control study. Nine participants receiving HSC transplantation and 8 participants receiving MSC transplantation during August 2006 and December 2010 in Department of Endocrinology, Nanjing Drum Tower Hospital Clinical College of Xuzhou Medical University were selected for analysis, meanwhile 10 matched participants who received insulin therapy alone during the same time period were enrolled as the control. Insulin injection dose, glycated hemoglobin A_1c (HbA_1c), fasting C-peptide (FCP) and 2h-postprandial C-peptide (2hCP) were collected before and 12 months after transplantation, and the change range of each index was calculated. Clinical remission was defined as a 10% increase from baseline in the levels of FCP and/or 2hCP. The adverse reactions of patients during the two kinds of stem cell transplantation and follow-up were observed to judge their safety. T-test, one-way analysis of variance, Mann-Whitney U test, Kruskal-Wallis H test, Fisher′s exact test were used to compare between the groups.

At the 12^th month of follow-up, the ratio of clinical remission in the HSC-treated, MSC-treated and control group were 7/9, 2/8, and 1/10 respectively, with HSC-treated group showing significantly higher ratio than that of control group (P=0.005). By the end of follow-up, the HbA_1c of the three groups were (6.5±1.3)%, (7.7±1.5)% and (9.2±3.5)%, respectively. The decrease of insulin injection dose and increase of FCP in HSC transplantation group were significantly higher than those in control group, and the increase of 2hCP in HSC transplantation group was significantly higher than that in MSC transplantation group and control group (P<0.05). Two recipients of HSC-treated group achieved insulin independence, but none in the MSC-treated group or control group. Compared to baseline in each group, HbA_1c (t=-3.85, P=0.008) and insulin injection dose (t=-2.47, P=0.039) were decreased and 2hCP (Z=-2.07, P=0.039) were increased at the end of follow-up in HSC-treated group, while HbA_1c (t=-3.11, P=0.017) and 2hCP (Z=-2.38, P=0.016) were decreased in MSC-treated group. Considering the safety of stem cell transplantation, all recipients in the HSC-treated group experienced some adverse events, while none presented in the MSC-treated group.

Both stem cell therapies improved glycemic control and preserved residue β-cell function in T1DM patients. HSC transplantation had a tendency to be superior to MSC transplantation in improving β-cell function, while the latter presented a higher safety profile.

Diabetes mellitus, type 1; Hematopoietic stem cell; Mesenchymal stem cell; Transplantation