Search

Introduction: Bacillus Calmette–Guérin (BCG) vaccination induces long-lasting effects on the adaptive and innate immune systems and prevents development of experimental autoimmune encephalomyelitis and possibly also inflammatory disease activity in multiple sclerosis (MS). Objective: The objective is to examine if BCG given in early adulthood decreases MS risk. Methods: From 791,369 (52% females) Norwegians participating in a national tuberculosis screening program from 1963 to 1975, we collected information on BCG vaccination and tuberculosis disease status. Later, MS disease was ascertained through both the Norwegian MS Registry and Biobank and the Norwegian Death Registry. We used logistic regression models to assess the relationship between BCG vaccination and MS risk. Results: In those BCG vaccinated, mean age at vaccination was 15.6 (standard deviation (SD) = 5.5) years. A total of 2862 (65% females) MS cases were retrieved. Overall, we found no association between MS risk and BCG vaccination. Compared to non-BCG-vaccinated individuals with no signs of tuberculosis infection, odds ratio (OR) for MS was 1.00 (95% confidence interval (CI) = 0.80–1.25) in the BCG-vaccinated group. In those not BCG vaccinated because of latent tuberculosis infection, the corresponding OR was 0.86 (95% CI = 0.66–1.13). Conclusion: We found no evidence of BCG vaccination or latent tuberculosis infection in young adulthood being linked to MS risk. [ABSTRACT FROM AUTHOR]

Background: Results from previous studies on a possible interaction between smoking and Epstein–Barr virus (EBV) in the risk of multiple sclerosis (MS) are conflicting. Objectives: To examine the interaction between smoking and infectious mononucleosis (IM) in the risk of MS. Methods: Within the case–control study on Environmental Factors In Multiple Sclerosis (EnvIMS), 1904 MS patients and 3694 population-based frequency-matched healthy controls from Norway, Italy, and Sweden reported on prior exposure to smoking and history of IM. We examined the interaction between the two exposures on the additive and multiplicative scale. Results: Smoking and IM were each found to be associated with an increased MS risk in all three countries, and there was a negative multiplicative interaction between the two exposures in each country separately as well as in the pooled analysis (p = 0.001). Among those who reported IM, there was no increased risk associated with smoking (odds ratio (OR): 0.95, 95% confidence interval (CI): 0.66–1.37). The direction of the estimated interactions on the additive scale was consistent with a negative interaction in all three countries (relative excess risk due to interaction (RERI): −0.98, 95% CI: −2.05–0.15, p = 0.09). Conclusion: Our findings indicate competing antagonism, where the two exposures compete to affect the outcome. [ABSTRACT FROM AUTHOR]

The article presents research which examines if body size influences the risk of multiple sclerosis (MS) in a population-based, case control study in Norway and Italy. It notes the definition of body size-related MS risk by odds ratios (ORs) in logistic regression analyses adjusting for age, smoking and outdoor activity. It reveals the possibility of obesity from childhood until young adulthood to be a risk factor for MS with a seemingly stronger effect in countries mentioned.

The article examines the association between multiple sclerosis (MS) and measures of sun exposure in specific age periods in Norway and Italy. The multinational case-control study (EnvIMS) study included 1660 MS patients and 3050 controls from Italy and Norway. It found converging evidence that underlines the beneficial effect of sun exposure on MS risk.