Objective To explore the significance of aryl hydrocarbon receptor (AhR) in patients with rheumatoid arthritis (RA) through detecting the levels of AhR and its response gene cytochrome P4501 A1 (CYP1 A1) in peripheral blood mononuclear cells (PBMCs).Methods Peripheral blood samples were collected from 35 patients with RA and 20 healthy subjects.The expression of AhR and CYP1A1 at mRNA level were detected by real-time PCR.The percentages of AhR-positive cells in PBMCs were detected by flow cytometry (FCM).The effects of leflunomide (LEF) on the expression of AhR and CYP1A1 were analyzed.The detailed clinical data of RA patients were recorded.The disease activity score (DAS) was calculated.Correlation analysis between AhR/CYP1A1 level and clinical data was conducted.Results (1) Both the expression of AhR at mRNA level and the percentage of AhR-positive cells in PBMCs from RA patients without LEF treatment were significantly higher than those from healthy subjects [(3.61±1.65) vs.(2.00±1.27),P=0.002; (34.21±11.30)％ vs.(18.83±7.32)％,P＜0.01].There were no statistically significant differences in the expression of AhR at mRNA level and the percentages of AhR-positive cells between patients with or without LEF treatment [(3.83 ± 1.62) vs.(3.61 ± 1.65),P =0.670 ; (36.69±10.61)％ vs.(34.21±11.30)％,P=0.462].(2) Non-LEF treatment group showed a higher relative expression of CYP1 A1 at mRNA level than that from control group [1.33 (0.08,7.86) vs.(0.62 ±0.29),z=-3.922,P＜0.01],but there was no statistical difference between LEF treatment group and non-LEF treatment group [(2.62±2.08) vs.1.33(0.08,7.86) z=-0.133,P=0.894].(3) Neither the expression of AhR and CYP1A1 at mRNA level nor the percentages of AhR-positive cells showed significant correlations with clinical data.Conclusion AhR was highly expressed in PBMCs from patients with RA,which might participate in the progression of rheumatoid arthritis.But the high expression of AhR did not reflect disease activity.Moreover,the treatment of LEF showed no significant influences on the expression of AhR and CYP1A1 in PBMCs from patients with RA.

Objective To explore the role of serum neutrophil extracellular traps (NETs) in rheumatoid arthritis (RA).Methods The serum circulating free DNA (cf-DNA) / NETs in 45 RA patients and 18 healthy controls were detected by Pico Green dsDNA Quantitation Kits,and the association between serum NETs and ESR,DAS28 score,anti-CCP antibodies was analyzed.T test,rank sum test,Pearson or Spearman correlation analysis were ued for statistical analysis.Results ① The levels of serum dsDNA/NETs in RA patients [0.523 0(0.282 0,1.637 0) μg/ml] were significantly higher than those in healthy controls [0.410 5 (0.140 0,0.966 0)μg/ml] (Z=-2.419,P=0.016).② The level of serum dsDNA/NETs in RA was positively correlated with ESR and DAS28 score (r=0.357,P=0.016; r=0.325,P=0.029),but not with anti-CCP antibodies(r=0.146,P=0.434).③ The levels of serum dsDNA/NETs in RA treated by DMARDs were lower than those of untreated with DMARDs[0.516 5(0.282 0,1.637 0) μg/ml,0.523 0 (0.369 0,1.485 0) μg/ml,Z=-1.215,P=0.225],but the difference was not significant.Conclusion NETs maybe associated with disease activity and play an important role in RA pathogenesis.

Objective To detect the levels of peptidylarginine deiminase 4 (PAD4) mRNA and neutrophil extracellular traps (NETs) of the peripheral blood neutrophils in rheumatoid arthritis (RA) patients and to study the association between PAD4 and NETs in RA.The anti-cyclic citrullinated peptide (anti CCP) antibodies,disease activity score (DAS28) score,erythrocyte sedimentation rate (ESR) were recorded.Its value in the pathogenesis of RA was explored.T test,rank-sum test,Pearson and Spearman correlative analysis were used for statical analysis.Methods The serum double-stranded DNA (dsDNA)/NETs in 43 RA patients and 20 healthy controls were detected by PicoGreen dsDNA Quantitation Kits (Invitrogen).Real-time quantitative polymerase chain reaction (RT-PCR) was used to determine the expression of PAD4 mRNA in neutrophils,and the relationship between dsDNA/NETs and their clinical indexes were analyzed.Results ① The level of peripheral blood neutrophils PAD4 mRNA in RA was significantly higher than healthy controls [1.493(0.831,2.607)] vs [0.631(0.358,1.489)],(Z=-2.07,P=0.039).The levels of serum PAD4 mRNA in RA treated with disease-modifying antirheumatic drugs (DMARDs) were lower than untreated with DMARDs but no significant difference was found (Z=-1.19,P=0.234).② The levels of serum dsDNA/NETs in RA patients were significantly higher than in healthy controls (t=3.4,P=0.001).③ The levels of serum dsDNA/NETs in RA were positively correlated with DAS28 score,ESR,CRP and PAD4 mRNA (r=0.36,P=0.036;r=0.345,P=0.042;r=0.36,P=0.043;r=0.42,P=0.017) but not with anti-CCP antibodies (r=0.277,P=0.154).Conclusion ① PAD4 may play an important role in the pathogenesis of RA.② NETs maybe associated with disease activity and play an important role in RA pathogenesis,inhibit NETs generation or improve the ability to clear NETs,perhaps can treat RA.③ PAD4 probably play an important role in rheumatoid arthritis by influencing the formation of the NETs.