Associations Between Infection and Multiple Sclerosis: A Case-Control Seroprevalence Study

Background: Currently, there are conflicting reports on the associations between infection and multiple sclerosis (MS) in humans. In the present study, a case-control study was carried out to assess associations between seropositivity to infection and MS.

Methods: This case-control study was carried out on 200 MS patients (cases) attended in Sina Hospital affiliated to Tehran University of Medical Sciences, Tehran, Iran, and 200 healthy subjects from the general population of the same city, March to July 2017. Blood samples were collected from individuals and were examined using Enzyme-linked immunosorbent assay (ELISA) for the presence of IgG antibodies and the IgG-positive samples were further analyzed for specific anti- IgM.

Results: The overall seroprevalence of anti- IgG was 44.2% (177/400) in 121 (60.5%) sera of the 200 MS patients (cases) and 56 (28.0%) sera of the 200 controls (OR = 3.94; 95% CI: 2.59-5.99; < 0.001). Seroprevalence of infection in MS patients increased significantly with increasing of age ( < 0.001). In the control group, no statistically significant differences were seen between the seroprevalence of infection in various age groups ( = 0.858). Moreover, no statistically significant relationships were reported between the seropositivity to and the sex for the cases and controls (>0.05). Anti- IgM antibodies were not detected in anti- IgG positive patients.

Conclusion: infection might be a probability risk factor for MS. However, further studies are necessary to describe clearly the roles of infection in MS.