ABSTRACT
Multiple sclerosis [MS] is a auto-immune disease of central nervous system. The etiology of MS is unknown, but environmental factors such as viruses are involved in the development of MS. In this study, MS patients were assessed for antibodies titers against Human Herpes virus-6 [HHV-6] in Markazi Province. In this case-control study, 31 new cases of MS patients and 60 healthy subjects were selected with similar demographic criteria such as sex, age and location. Antibodies titer [IgM and IgG] against HHV-6 were examined by ELISA and Immunofluorescence methods. Data were analyzed using Logistic regression and Odds ratio. Data indicates that 74.2% of case group and 34.2% of control group were identified as positive for IgM against HHV-6. The difference between the two groups in terms of IgM against HHv-6 was statistically significant [p=0.001]. Incidence of IgM positivity against HHV-6 was increased more than five times in MS patients compared to control group. Also there was a statistically significant difference between case and control groups in IgG titer [p=0.019]. Acute infection of HHV-6 is a risk factor for MS