ABSTRACT
Objective:To explore the characteristics of intestinal microbiota in patients with systemic lupus erythematosus (SLE), and further explore the relationship between microbiota and CD4 +T lymphocyte subsets and disease activity. Methods:Fecal samples were collected from 96 patients with SLE, and 96 sex- and age-matched healthy controls (HCs). The gut microbiota were investigated via 16s rRNA sequencing. Flow cytometry was used to detect peripheral CD4 +T lymphocyte subsets of Th1, Th2, Th17 and Treg cells. Indicators of disease activity such as erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complement C3 and C4, Systemic lupus erythematosus disease activity index(SLEDAI) for each patient were recorded. Differential abundance analysis was carried out using the edgeR algorithm. The Wilcoxon rank-sum test was used to compare alpha diversity indices, bacterial abundances, and the F/B ratio between groups. R (version 4.0.1) was used for comparative statistics, and Pearson′s correlation analysis was used to assess the correlations between the relative abundances of bacterial genera and serum levels of ESR, CRP, C3 and C4 in the samples. Results:The alpha estimators of richness (ACE and Chao 1) were significantly reduced in SLE feces samples compared with those of HCs ( P<0.01). Bacterial diversity estimators, including the Shannon ( P<0.01) and Simpson′s ( P<0.01) indices, were also significantly lower in SLE. Significant differences in gut microbiota composition between SLE and HCs were found using the edgeR algorithm. Compared with HC, 24 species of bacteria were significantly different in SLE patients at the genus level ( P<0.05). Moreover, there was a significant positive correlation between CRP and Coprococcus ( r=0.30, P=0.014), C4 and Corynebacterium ( r=0.31, P=0.013) and Faecalibacterium( r=0.25, P=0.048), Hemoglobin and Morganella( r=0.41, P=0.001), as well as SLIDA and Corynebacterium( r=0.25, P=0.047). In terms of lymphocyte subsets, there was significant positive correlation between B cells, Treg cells and Eubacterium eligens group, as well as CD8 +T, CD4 +T, NK cells and Corynebacterium. In additional, Th1 was positively correlated with Shigella Escherichia coli ( r=0.52, P=0.008), and Th2 was positively correlated with Dielma ( r=0.51, P<0.001). Conclusion:The abundance and diversity of intestinal flora in SLE patients were significantly reduced, and the differentially expressed bacteria were closely related to the CD4 +T lymphocyte subsets and disease activity indicators of patients.
ABSTRACT
Background The pathogenesis of dry eye has not been clearly established.There are more and more evidences to suggest that it is associated with ocular surface inflammation mediated by immunity.But how T helper cell 17 (Th17) plays its role in dry eye remains unclear.Objective The aim of this study was to investigate the expressions of Th17 related cytokines in ocular surface with dry eye.Methods A prospective cohortl study was designed.This protocol was approved by Ethic Commission of Peking University Third Hospital,and written informed consent was obtained from each subject prior to entering this cohort.Twenty female patients with Sjigren syndrome (SS group),20 patients with non-SS dry eyes and 20 normal volunteers were recruited in Peking University Third Hospital during 2011-2012 duration and all the subjects were menopausal female with the age 50 years old or more.The ocular surface disease index (OSDI)questionnaire designed by Schiffman was performed firstly,and then tear breakup time (BUT),corneal fluorescein staining and Schirmer Ⅰ test (S Ⅰ t) were carried out in the subjects.Expression of Th17 related cytokines mRNA were measured using PCR-Array.The correlation between IL-17A and ocular surface parameters was analyzed.Results The OSDI scores of the SS dry eye group,non-SS dry eye group and normal control group were 50.00 (33.50,66.50),45.00 (35.50,55.00) and 3.00 (0.00,5.00),the S Ⅰ t values were 2.50 (1.00,4.00),5.00 (2.00,5.00) and 15.50 (10.00,18.50),the BUT were 2.00 (1.00,4.00),4.00 (3.00,5.00) and 10.00 (10.00,12.00),the corneal fluorescein staining score were 8.50 (6.00,12.00),5.50 (4.00,7.00)and 0.00 (0.00,0.00),respectively,and significant differences were seen among the SS group,non-SS dry eye group and normal control group (x2=34.11,28.13,93.66,92.25,all at P<0.01).The relative expression values of IL-17A mRNA,IL-6 mRNA,IL-8 mRNA,IL-22 mRNA and IL-23 mRNA in the ocular surface were 1.98±0.16,11.64±1.32,6.67±1.12,1.88±0.18 and 1.78±0.17 in the SS group patients,and 1.45±0.17,1.32±0.14,1.12 ±0.13,1.23 ±0.15 and 1.23 ±0.13 in the non-SS dry eye group patients,respectively,with significant differences between the two groups (all at P<0.01).IL-17A level on the ocular surface was significantly negative correlated with BUT (r =-0.56,P<0.01) and positive correlation with corneal fluorescein staining scores (r=0.44,P=0.01).Conclusions Expressions of Th17 related cytokines in the ocular surface increased in patients with dry eye,especially in those with SS.IL-17A level in ocular surface is associated with BUT and corneal fluorescein staining scores,suggesting that immune is involved in the pathogenesis and devlopment of dry eye.