No abstract

Myeloid-derived suppressor cells (MDSCs) are a group of cells that regulate the immune response and exert immunosuppressive effects on various immune cells. Current studies indicate that MDSCs have both anti-inflammatory effects and proinflammatory effects on rheumatoid arthritis (RA) and RA animal models. MDSCs inhibit CD4 + T cells, which secrete proinflammatory factors such as IFN-γ, IL-2, IL-6, IL-17, and TNF-α, by inhibiting iNOS, ROS, and IFN-γ and promoting the production of the anti-inflammatory factor IL-10. MDSCs can suppress dendritic cells by reducing MHC-II and CD86 expression, expand Treg cells in vitro through the action of IL-10, inhibit B cells through NO and PGE 2, and promote Th17 cell responses by secreting IL-1β. As a type of osteoclast precursor cell, MDSCs can differentiate into osteoclasts through activation of the NF-κB pathway via IL-1α. Overall, our study reviews the research progress related to MDSCs in RA, focusing on the effects of MDSCs on various types of cells and aiming to provide ideas to help reveal the important role of MDSCs in RA.

Background: Zheng Qing Feng Tong Ning (ZQFTN) is a sinomenine (SIN) preparation that has been used in clinical practice. Our study aimed to assess the methodological and reporting quality of meta-analyses on the Chinese herbal formula ZQFTN for the treatment of rheumatoid arthritis (RA). Methods: Systematic searches were carried out with the 5 following electronic databases from inception to July 2019: China National Knowledge Infrastructure (CNKI), Wanfang, VIP database for Chinese technical periodicals (VIP), Cochrane Library and PubMed. The quality of the methodology and reporting was measured with the assessment of multiple systematic reviews 2 (AMSTAR 2) scale, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Results: Eight studies were identified. Among the 16 items of the AMSTAR 2 scale, four items were optimally reported ("Y" =100% of the items), and another four items were poorly reported ("Y" =0% of the items). Only 2 studies received a good overall score ("Y" ≥50% of the items). Regarding the PRISMA statement, the scores of 5 studies were lower than the average score (17.69), indicating that the quality of the reports was very low. In terms of the GRADE, none of the 61 results were of high quality (0.0%). Fifteen results were of medium quality (25%), 34 were of low quality (55%), and 12 were of very low quality (20%). Among the five downgrading factors, deviation risk (n = 61, 100%) was the most common downgrading factor, followed by inconsistency (n = 30, 50%), publication bias (n = 17, 28%), inaccuracy (n = 11, 18%) and indirectness (n = 0, 0%).