Study On The Relationship Between Intestinal Flora And Peripheral Cytokines In Patients With Rheumatoid Arthritis

Objective:1.To detect the characteristics of flora in the stool of patients with rheumatoid arthritis(RA)and healthy controls,and analyze the changes in the abundance and diversity of intestinal flora in patients with RA.2.To analyze the correlation between the changes of intestinal flora in the RA group and its erythrocyte sedimentation rate(ESR),C reaction protein(CRP),RF,ACPA,disease course and DAS28 score.3.Analyzed the correlation between the intestinal flora of RA patients and the peripheral cytokines TNF-α,IL-6 and IL-17 A.And further to reveal the relationship between changes in intestinal flora and the onset of RA,which aims to provide new ideas for clinical treatment.Methods:A collection of 111 RA patients hospitalized in the Second Hospital of Shanxi Medical University from January 2019 to January 2020 were included in the RA group.The diagnosis of all RA patients met the 2009 ACR/EULAR classification criteria for RA.A total of 100 healthy people who were examined by the Health Examination Center of Shanxi Provincial People’s Hospital were selected as the healthy control group.All volunteers BMI<28 kg/m2;age 18~80 years old;no antibiotics or probiotics,prebiotics and other micro-ecological regulators in the past 1 month;no enema in the past 3 months;no partial eclipse,diet or other diet preferences.We collected the clinical parameters(i.e,age,sex,disease duration,ESR,CRP,RF,ACPA)and peripheral venous blood and feces of the above research subjects,and use flow cytometry to detect peripheral cytokines.The bacterial diversity and abundance of 111 RA patients and 100 age–and gender–matched healthy controls(HC)were detected by 16s high –throughput sequencing platform and compared.Based on the 16 S rDNA high –throughput sequencing platform,the 16 S rDNA V3 region in participants’ fecal specimens were analyzed and compared to screen for different bacterial groups.Alpha diversity was analyzed by using mothur software and the screen different flora was tested by using Mann–Whitney.Spearman correlation analysis was used to determine the correlation between the changes of the intestinal flora and clinical parameters,DAS28 score,and the peripheral blood cytokines TNF-α,IL-6 and IL-17 A of the RA patients.Results:1.There was no significant difference in gender(χ2=0.005,P=0.947)and age(t=0.728,P=0.467)between the two groups.2.Patients with RA had a lower chao1 index(Z=–2.188,P=0.029)and ACE index(Z=–2.078,P=0.038)of species richness,and the Shannon index(Z=–2.064,P=0.039)and Simpson index(Z=–2.064,P=0.039)of diversity index in the feces compared with those of HC.3.At the genus level,the relative abundance of Bifidobacterium(Z=–2.388,P=0.017),Lactobacillus(Z=–2.543,P=0.011),Clostridium sensu stricto(Z=–3.842,P<0.001),Clostridium XI(Z= – 2.682,P=0.007),Turicibacter(Z= – 2.437,P=0.015),Phascolarctobacterium(Z=–3.524,P<0.001),Megasphaera(Z=–2.870,P=0.004),Veillonella(Z= – 2.472,P=0.013),Citrobacter(Z= – 3.263,P=0.001)and Escherichia/Shigella(Z=–4.265,P<0.001)in RA were significantly higher than those of HC(P<0.05),While reative abundance of Butyricimonas(Z= – 3.071,P=0.002),Odorbacter(Z=–2.257,P=0.024),Blautia(Z=–2.064,P=0.039),Clostridium Xl Vb(Z=–2.901,P=0.004),Lachnospiracea incertae sedis(Z=–2.159,P=0.031),Acetivibrio(Z=–2.995,P=0.003),Butyricicoccus(Z=–2.162,P=0.031)and Gemmiger(Z=–2.949,P=0.003)relative abundance were significantly decreased in RA patients.4.LEfSe analysis showed Gammaproteobacteria and Lachnospiraceae(LDA 值>±4)had the most significant difference between the two groups.Further,patients with high inflammatory cytokines such as IL-17 and TNF-α had a higher relative abundance of Prevotella.Conclusion:The diversity and abundance of intestinal flora in RA patients were significantly different from those of healthy population,which is closely related to the levels of inflammatory cytokines,suggesting imbalance of intestinal flora might be involved in the occurrence and development of RA.