Associations between Toxoplasma gondii Infection and Multiple Sclerosis: A Case-Control Seroprevalence Study

Abstract

Background: Currently, there are conflicting reports on the associations between Toxoplasma gondii infection and multiple sclerosis (MS) in humans. In the present study, a case–control study was carried out to assess associations between sero-positivity to T. gondii infection and MS. Methods: This case-control study was carried out on 200 MS patients (cases) at-tended in Sina Hospital affiliated to Tehran University of Medical Sciences, Teh-ran, 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 ex-amined using Enzyme-linked immunosorbent assay (ELISA) for the presence of T. gondii IgG antibodies and the IgG-positive samples were further analyzed for specific anti-T. gondii IgM. Results: The overall seroprevalence of anti-T. gondii 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; P < 0.001). Seroprevalence of T. gondii infection in MS patients increased significantly with increasing of age (P < 0.001). In the control group, no statistically significant differences were seen between the seroprevalence of T. gondii infection in various age groups (P = 0.858). Moreover, no statistically significant relationships were reported between the seropositivity to T. gondii and the sex for the cases and controls (P>0.05). Anti-T. gondii IgM antibodies were not detected in anti-T. gondii IgG positive patients. Conclusion: T. gondii infection might be a probability risk factor for MS. However, further studies are necessary to describe clearly the roles of T. gondii infection in MS.