Objective:To evaluate the risk factors of rheumatoid arthritis associated interstitial lung disease (RA-ILD).Methods:Databases including PubMed, Sinomed, Embase, Wiley Online library were searched to collect studies on risk factors of RA-ILD. The deadline of the search was January 1 2021. Newcastle-Ottawa Scale (NOS) was used to assess the literature quality, data was extracted and analyzed by Statistical software in eligible studies.Results:This meta-analysis included 36 studies involving 3 280 patients with RA-ILD and 25 510 RA controls patients. The Incidence of RA-ILD was 6.25%. The risk of RA-ILD was 2.51 times greater in men than in women [ OR(95% CI)=2.51(2.25, 2.80)]. The mean onset age of patients with RA-ILD was 7.47 years [56.50 vs 49.04, 95% CI(6.56, 8.38)] older than those of patients with RA-nILD. The mean duration of patients with RA-ILD was 1.11 years longer than that of patients with RA-nILD [7.73 vs 6.62, 95% CI(0.68, 1.55)]. The risk of RA-ILD was two times greater in smoker than in non-smoker [ OR(95% CI)=2.25(2.01, 2.52]). Moderate evidence indicated that higher erythrocyte sedimentation rate(ESR), C-reactive protein(CRP), disease activity score in 28 joints (DAS28)-ESR were risk factors for RA-ILD[Stan-dard Mean Difference ( SMD)(95% CI)=0.25(0.18, 0.31); SMD(95% CI)=0.25(0.18, 0.32); SMD(95% CI)=0.36(0.27, 0.45), respectively). The pooled [ OR(95% CI)=1.71(1.45, 2.01)] in rheumatoid factor (RF) positive and [ OR(95% CI)=2.41(1.80, 3.23)] anti-CCP antibody positive for the risk of RA-ILD. Conclusion:Male, smoking, older age of disease onset, long disease duration, elevated erythrocyte sedimentation rate, high C-reactive protein level, high DAS28-ESR, positive RF and anti-cyclic peptide containing citrulline antibody were risk factors for RA-ILD.

ObjectiveTo observe the effect of classic prescription Ermiaosan （EMS） on the differentiation of T helper 17 （Th17） /regulatory T （Treg） cells in collagen-induced arthritis （CIA） DBA/1 mice. MethodDBA/1 mice were randomized into normal group， CIA group， EMS （5.4 g·kg^-1） group， and methotrexate （MTX，0.5 mg·kg^-1） group according to the body weight. DBA/1 mice in CIA group， EMS group， and MTX group were immunized with equal volume of bovine type Ⅱ collagen and complete Freund's adjuvant on the first day and were immunized with equal volume of bovine type Ⅱ collagen and incomplete Freund's adjuvant on the 21^st day to induce CIA. On the day of the secondary immunization， intragastric administration started and lasted 28 days （three times/week for MTX group， and once/day for other groups）. The symptoms of CIA mice such as joint redness and swelling were observed from the 22^nd day， and the arthritis was scored. After the sampling on the 49^th day， synovitis of CIA mice was observed based on hematoxylin-eosin （HE） staining. Double-labeling immunofluorescence （IF） method was used to detect the expression of Th17 cell marker IL-17 and Treg cell marker forkhead transcription factor P3 （FoxP3） in CD4⁺T cells in CIA mouse joints. The proportion of Th17 and Treg cells in the spleen and lymph nodes of mice was detected by flow cytometry. ResultCompared with the normal group， CIA group had obvious synovitis， disordered joint structure， severely damaged articular cartilage and bone， serious bone erosion （P<0.01）， high Th17/Treg value in joint tissue （P<0.01）， high proportion of Th17 cells in spleen and lymph nodes （P<0.01）， and low proportion of Treg cells （P<0.01）. Compared with CIA group， EMS group and MTX group had normal joint structure， mild bone erosion and bone destruction， complete and smooth joint surface， low Th17/Treg value （P<0.01）， low proportion of Th17 cells in spleen and lymph nodes （P<0.01）， and high proportion of Treg cells in spleen and lymph nodes （P<0.01）. ConclusionEMS regulates the balance of Th17/Treg， inhibits the expression of Th17 cells， and promotes the expression of Treg cells in CIA mice， thereby exerting therapeutic effect on RA.