Clinical Significance Of CXCL10,TARC,MDC And Their Receptors In Idiopathic Inflammatory Myopathies

OBJECTIVE: To investigate the serum levels of Th1 chemokine CXCL10 and Th2 chemokines TARC,MDC and the corresponding chemokine receptor CXCR3 and CCR4 expression on the surface of different T cell subsets in peripheral blood in patients with polymyositis(PM)and dermatomyositis(DM),we organized this experiment.At the same time,we explored the clinical significance of chemokine levels and their receptors expression in the two diseases.METHODS: This cohort consisted of prospectively enrolled patients between 2015 and 2016 from the Department of Rheumatology and Immunology of the First Affiliated Hospital of China Medical University.Fifty-seven patients suffering from PM(n=24)or DM(n=33,including 16 CADM)and 20 healthy controls matched for age and sex were enrolled in this study.Exclusion criteria were presence of overlap syndrome,neoplasm,infection or treatment with biologicals.Flow cytometry was used to detect the expression of chemokine receptors CXCR3 and CCR4 on CD4 + and CD8 + T lymphocytes in peripheral blood of patients and healthy controls.Serum concentrations of soluble chemokines IFN-?-inducible protein 10(IP-10),thymic activation-regulated chemokines(TARC)and macrophage-derived chemotactic factor(MDC)were measured by enzyme-linked immunosorbent assay(ELISA).Patient's clinical symptoms,laboratory test indicators,test results and other data were collected.Data are expressed as mean ± SD(standard deviation).One-way ANOVA followed by Tukey multiple comparison test was used to compare the differences.Correlations between variables were assessed by Pearson regression using the SPSS software.A significant difference was defined as p<0.05.RESULTS: Our results suggest that the percentage of CD8+CXCR3+cells in PM patients was decreased compared with healthy controls.The percentage of CD4+CXCR3+ and CD8+CXCR3+ cells in peripheral blood of DM patients was significantly lower than that of PM patients.The percentage of CD8+CXCR3+ cells in DM patients was lower than that in PM patients.There was no significant difference in the percentage of CD4+CCR4+ and CD8+CCR4+ cells between PM and DM patients.Accordingly,the ratio of %CD4+CXCR3+ and %CD4+CCR4+ were significantly lower in DM patients and no significant difference between PM patients and healthy controls.Compared with healthy controls,the levels of CXCL10 in serum of patients with PM and DM were significantly increased,and the levels of CXCL10 in DM patients were higher than those in PM patients.There was no significant change in TARC and MDC levels in patients with PM and DM.In addition,the concentration of CXCL10 in DM patients was inversely correlated with the percentage of CD4+CXCR3+ cells and the percentage of CD8+CXCR3+ cells.There was no significant correlation between the percentages of TARC,MDC and CCR4+ cells.In addition,65% of DM and PM patients have ILD.Lymphocyte counts were significantly lower in PM and DM patients as compared to healthy controls.The percentage of CD4+CXCR3+ cells in patients with interstitial lung disease is more severely decreased.CONCLUSIONS: We found that the distribution of CXCR3+ and CCR4+ T cell subsets in PM and DM patients is different,which may be related to the different mechanism of T cell infiltration in muscle tissue between PM and DM patients.Our experimental results may provide a new perspective for studying the pathogenesis of connective tissue disease and help to update and develop the early diagnosis and treatment of PM and DM.