Lack of persistent remission following initial recovery in patients with type 1 diabetes treated with autologous peripheral blood stem cell transplantation

Efficacy of mesenchymal stromal cells in the treatment of type 1 diabetes: a systematic review

To investigate the efficacy of mesenchymal stromal cells in the treatment of type 1 diabetes. Articles about the effects of mesenchymal stromal cells for T1D were retrieved in PubMed, Web of Science, Embase, and the Cochrane Library databases up to July 2023. Additional relevant studies were manually searched through citations. HbA1c, FBG, PBG, insulin requirement and C-peptide were assessed. The risk of bias was evaluated with the ROB 2.0 and ROBINS-I tools. Six RCTs and eight nRCTs were included. Of the 14 studies included, two evaluated BM-MSCs, three evaluated UC-MSCs, five evaluated AHSCT, two evaluated CB-SCs, and two evaluated UC-SCs plus aBM-MNCs. At the end of follow-up, ten studies found that mesenchymal stromal cells improved glycemic outcomes in T1D, while the remaining four studies showed no significant improvement. Findings support the positive impacts observed from utilizing mesenchymal stromal cells in individuals with T1D. However, the overall methodological quality of the identified studies and findings is heterogeneous, limiting the interpretation of the therapeutic benefits of mesenchymal stromal cells in T1D. Methodically rigorous research is needed to further increase credibility.

Hematopoietic Stem Cells in Type 1 Diabetes

Despite the increasing knowledge of pathophysiological mechanisms underlying the onset of type 1 diabetes (T1D), the quest for therapeutic options capable of delaying/reverting the diseases is still ongoing. Among all strategies currently tested in T1D, the use of hematopoietic stem cell (HSC)-based approaches and of teplizumab, showed the most encouraging results. Few clinical trials have already demonstrated the beneficial effects of HSCs in T1D, while the durability of the effect is yet to be established. Investigators are also trying to understand whether the use of selected and better-characterized HSCs subsets may provide more benefits with less risks. Interestingly, ex vivo manipulated HSCs showed promising results in murine models and the recent introduction of the humanized mouse models accelerated the translational potentials of such studies and their final road to clinic. Indeed, immunomodulatory as well as trafficking abilities can be enhanced in genetically modulated HSCs and genetically engineered HSCs may be viewed as a novel "biologic" therapy, to be further tested and explored in T1D and in other autoimmune/immune-related disorders.

Efficacy and Safety of Stem Cell Therapy for T1DM: An Updated Systematic Review and Meta-Analysis

BACKGROUND

The long-term insulin therapy for type 1 diabetes mellitus (T1DM) fails to achieve optimal glycemic control and avoid adverse events simultaneously. Stem cells have unique immunomodulatory capacities and have been considered as a promising interventional strategy for T1DM. Stem cell therapy in T1DM has been tried in many studies. However, the results were controversial. We thus performed a meta-analysis to update the efficacy and safety of stem cell therapy in patients with T1DM.

METHODS

We systematically searched the Medline, EMBASE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Web of Science, Wan Fang Data, China National Knowledge Infrastructure, VIP database, and the Chinese Biomedical Literature Database (SinoMed) for relevant studies published before March 19, 2019. The outcomes included parameters for glycemic control (i.e., glycosylated hemoglobin (HbA1c) levels and insulin dosages), β cell function (i.e., fasting C-peptide levels and area-under-curve of C-peptide concentration (AUCC)), and relative risk of adverse events. Statistical analysis was conducted by using RevMan 5.3 and Stata 12.0.

RESULTS

Five randomized controlled trials (RCTs) and eight nonrandomized concurrent control trials (NRCCTs) with a total of 396 individuals were finally included into the meta-analysis. Among RCTs, stem cell therapy could significantly reduce HbA1c levels (MD = -1.20, 95% CI -1.91 to -0.49, P = 0.0009) and increase fasting C-peptide levels (MD = 0.25, 95% CI 0.04 to 0.45, P = 0.02) and AUCC (SMD = 0.66, 95% CI 0.13 to 1.18, P = 0.01). Stem cell therapy could also reduce insulin dosages (SMD = -2.65, 95% CI -4.86 to -0.45, P = 0.02) at 6 months after treatment. NRCCTs also had consistent results. Furthermore, RCTs showed stem cell therapy did not increase relative risk of gastrointestinal symptom (RR = 0.69, 95% CI 0.14 to 3.28, P = 0.64) and infection (RR = 0.97, 95% CI 0.40 to 2.34, P = 0.95). However, NRCCTs showed stem cell therapy increased relative risk of gastrointestinal symptom (RR = 44.49, 95% CI 9.20 to 215.18, P < 0.00001).

CONCLUSION

Stem cell therapy for T1DM may improve glycemic control and β cell function without increasing the risk of serious adverse events. Stem cell therapy may also have a short-term (3-6 months) effect on reducing insulin dosages.