Serum level of interleukin-6 in Chinese patients with multiple sclerosis

The aim of this study was to investigate the serum concentration of interleukin (IL)-6 in patients with relapsing-remitting MS (RR-MS), compare the difference between males and females, and explore the correlation between the serum concentration of IL-6 and clinical parameters like the current age, the age at onset, disease duration, disability (expanded disability status scale, EDSS), and the number of relapse. We compared the serum concentration of IL-6 in 39 patients with MS and 39 healthy controls matched with sex and age. The serum IL-6 concentration was measured by FlowCytomix. Compared to healthy controls, both the frequency of subjects with detectable level of IL-6 (P=0.005) and the serum concentration of IL-6 (P=0.004) were significantly higher in MS patients. When data were analyzed by gender, statistical significances between MS patients and healthy controls were observed only in females, although the frequency with detectable level and the serum concentration of IL-6 were higher in male MS patients than male controls. The serum level of IL-6 was found to be significantly positively correlated with the number of relapse for female MS patients (r(s)=0.511, P=0.009), with the current age for male MS patients (r(s)=0.700, P=0.005), and with the age at onset for all MS patients (r(s)=0.351, P=0.028). Our results may support that IL-6 is involved in the pathogenesis of MS and indicate that differences exist between male and female patients.