Mesenchymal stem cell therapy efficacy in COVID-19 patients: A systematic review and meta-analysis

Objective: To evaluate mesenchymal stem cell (MSC) administration safety and efficacy in COVID-19 patients. Methods: We conducted a literature search on PubMed/MEDLINE, medRxiv, EBSCOhost/CINAHL, ProQuest, and Scopus with keywords adjusted to each search engine’s specifications on February 12, 2021. Interventional studies that reviewed MSC efficacy (mortality, hospitalization duration, need for mechanical ventilators, and inflammation markers) and/or safety (adverse events) in COVID-19 patients who were 18 years old or more were included in this study. Study eligibility, data extraction, and study quality assessment were conducted independently by each author. Results: A total of five studies of moderate to high quality with a total of 193 patients were included. One of the three randomized studies included did not apply blinding to either participants or medical professionals. Pooled OR (Odd Ratio) for mortality risk, adverse events incidence, and use of mechanical ventilators for patients on MSC therapy were 0.13 [95% CI: 0.02, 0.68], 0.91 [95% CI: 0.45, 1.86], and 0.42 [95% CI: 0.12, 1.47], respectively. Pooled mean difference for hospitalization duration in the MSC group versus the control was -3.54 [CI 95%: -4.68, -2.40] with 7% heterogeneity. All studies agreed that there was an increase of pro-inflammatory cytokines and a decrease of anti-inflammatory markers that were statistically different in the MSC group. Conclusion: Mesenchymal stem cell administration to COVID-19 patients is safe and effective in reducing mortality and hospitalization duration. Furthermore, a decrease of pro-inflammatory cytokines and an increase in anti-inflammatory cytokines were observed.