Combination treatment with interferon-γ may be a potential strategy to improve the efficacy of cytotherapy for rheumatoid arthritis: A network meta-analysis.

Background: Mesenchymal stem cells (MSCs) are considered a promising therapeutic strategy for rheumatoid arthritis (RA), but the current clinical results are varied. This study is to analyze the therapeutic effect of cell-based strategies on RA.

Materials and methods: The searches were performed with public databases from inception to June 17, 2021. Randomized controlled trials researching cell-based therapies in RA patients were included.

Results: Eight studies, including 480 patients, were included in the analysis. The results showed that compared to the control, MSC treatment significantly reduced the disease activity score (DAS) at the second standardized mean difference (SMD): -0.70; 95% confidence interval (CI): -1.25, -0.15; P = 0.01) and 3^rd month (SMD: -1.47; 95% CI: -2.77, -0.18; P < 0.01) and significantly reduced the rheumatoid factor (RF) level at the first (SMD: -0.38; 95% CI: -0.72, -0.05; P = 0.03) and 6^th months (SMD: -0.81; 95% CI: -1.32, -0.31; P < 0.01). In the network meta-analysis, MSCs combined with interferon-γ (MSC_IFN) had a significant effect on increasing the American college of rheumatology criteria (ACR) 20, ACR50, and DAS <3.2 populations, had a significant effect on reducing the DAS, and decreased the RF level for a long period.

Conclusion: MSCs could relieve the DAS of RA patients in the short term and reduce the level of RF. MSC_IFN showed a more obvious effect, which could significantly improve the results of ACR20, ACR50, and DAS <3.2 and reduce the DAS and RF levels.