Serum Levels Of Il-18 In Patients With Polymyositis And Dermatomyositis

Objective:the aim of this study was to detected the serum levels of IL-18 in patients with polymyositis(PM) and dermatomyositis(DM) and to investigate the correlation between the serum levels of IL-18 and disease activity in patients with PM/DM.Methods:Sixty patients with PM/DM,40 patients with systemic lupus erythematosus (SLE) and 30 patients rheumatoid arthritis(RA) as disease controls, and 30 normal controls were enrolled in this study. Serum levels of IL-18 were detected by enzyme linked immunosorbent assay (ELISA). The correlations between the serum level of IL-18 and the disease activity parameters were analyzed.Results:The serum levels of IL-18 in patients with PM/DM were significantly higher than that in normal controls (212.57±174.62pg/ml, versus 23.25±12.30pg/ml, p<0.001). Furthermore, the serum levels of IL-18 in active stage of PM/DM patients were signifycantly higher than that in inactive stage (273.57±180.72pg/ml, versus 78.60±39.04pg/ml, p<0.001). Meanwhile, the serum levels of IL-18 showed positive correlations with the serum creatine kinase (CK), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), respectively. There was no significant difference of the serum levels of IL-18 between PM and DM patients. In addition, serum levels of IL-18 was higher in patients with SLE and RA, and correlated with disease activity, respectively.Conclusion The serum levels of IL-18 were outstandingly elevated in patients with PM/DM and positively associated with disease activity, which indicates that IL-18 may have a vital role in the pathogenesis of PM/DM. The serum levels of IL-18 may be used as biomarker for disease activity of PM/DM.