Standard treatment options for rheumatoid arthritis (RA) often fail to deliver a long-term therapeutic outcome and in many cases cause intractable adverse events leading to treatment discontinuation or readjustment. Treatment with mesenchymal stem cells (MSCs) has been recently studied in RA due to its immunomodulatory and anti-inflammatory capacities. Thus, this study aims at systematically search and review the literature for randomized or non-randomized clinical trials comparing interventions of MSCs with placebo in RA patients. Electronic searches were conducted on PubMed, SCOPUS, Cochrane-CENTRAL, registries of clinical trials and grey literature. Selected studies were estimated for risk of bias with the Cochrane RoB tool 2 or the ROBINS-I tool. Four trials met the eligibility criteria and entered the review process. Identified MSCs treatments varied from allogeneic to autologous or umbilical cord-derived cells. Enrolled patients had an active RA and had poor responses to previous standard medications. In general, the safety evaluation revealed that treatment with MSCs was safe and well tolerated. Regarding the efficacy measurements, modest improvements were found in RA symptoms and RA-related indices. Significant decreases were found in inflammatory molecules such as C-reactive protein, tumor necrosis factor alpha and interleukin 6. However, clinical response criteria related to RA were achieved by a low-to-moderate percentage of patients. In conclusion, treatment of RA with MSCs appears to have a short-term therapeutic effect. Better-designed randomized trials with sufficient follow-up periods are needed so that the long-term safety and efficacy interventions with MSCs would be elucidated.

中文翻译：

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类风湿关节炎间质干细胞的治疗潜力：体内研究的系统评价。

类风湿性关节炎（RA）的标准治疗选择通常无法提供长期的治疗效果，并且在许多情况下会引起棘手的不良事件，导致治疗中断或调整。由于其免疫调节和抗炎能力，最近在RA中研究了间充质干细胞（MSCs）的治疗。因此，本研究旨在系统地搜索和审查文献，以比较MSC与安慰剂对RA患者的干预作用的随机或非随机临床试验。在PubMed，SCOPUS，Cochrane-CENTRAL，临床试验注册处和灰色文献上进行了电子检索。使用Cochrane RoB工具2或ROBINS-I工具估算了所选研究的偏倚风险。有四项试验符合资格标准，并进入了审查过程。鉴定的MSCs处理方法从同种异体细胞到自体或脐带来源的细胞不等。入选患者活动性RA，对以前的标准药物反应较差。一般而言，安全性评估表明，用MSC治疗是安全且耐受性良好的。关于功效测量，在RA症状和RA相关指数中发现了适度的改善。在炎症分子（例如C反应蛋白，肿瘤坏死因子α和白介素6）中发现显着降低。但是，与RA相关的临床反应标准是通过中低百分比的患者实现的。总之，用MSC治疗RA似乎具有短期治疗作用。