Association of helicobacter pylori with multiple sclerosis: Protective or risk factor?

Background: Multiple sclerosis (MS) is a common autoimmune inflammatory disease in the central nervous system (CNS) without exact pathology. Environmental factors such as infections have a causal or protective role in MS. Helicobacter pylori (HP) is one of the infections in digestive diseases and previous studies reported controversial findings of this infection role in MS. So, we conducted this study to assess the frequency of HP infection in patients with MS in comparison to the healthy population. Methods: This cross-sectional study was undertaken between 2015 and 2019. 191 participants including 58 patients with clinically isolated syndrome (CIS), 57 patients with relapsing-remitting MS (RRMS), 39 patients with secondary progressive MS (SPMS), and 39 age- and sex-matched healthy controls (HCs) were tested for the presence of HP immunoglobulin G (IgG) and IgM antibodies (Abs) in their serum sample. Results: The frequency of HP IgG seropositivity in patients with SPMS was significantly higher than patients with CIS [Odds ratio (OR): 6.333, 95% confidence interval (CI): 2.522-15.906, P < 0.001], patients with RRMS (OR: 4.583, 95% CI: 1.842-11.407, P = 0.001), and HCs (OR: 8.485, 95% CI: 3.058-23.540, P < 0.001). We did not find a significant difference among other study groups regarding IgG seropositivity. No significant difference among groups regarding HP IgM seropositivity was evident. On univariate model, Expanded Disability Status Scale (EDSS) score (OR: 1.038, 95% CI: 1.038-1.460, P = 0.017) and SPMS (OR: 4.583, 95% CI: 1.842-11.407, P = 0.001) were predictor for HP IgG seropositivity. On multivariate model, only SPMS had higher risk for HP IgG seropositivity compared to RRMS (OR: 5.554, 95% CI: 1.327-23.253, P = 0.019). We did not find a significant association between clinical and demographic variables with HP IgM seropositivity. Conclusion: Based on our findings, progressive MS and HP infection may have association. Further longitudinal studies with large sample size are needed to determine the role of HP infection in MS.