Overweight / obese BMI values at the age of 20, coupled with a history of infectious mononucleosis (IM) or high antibody levels of Epstein-Barr core antigen 1 (EBNA-1), act synergistically in increasing the risk of multiple sclerosis (MS) ) and the effect increases with increasing antibody levels according to the study results published in Neurology: Neuroimmunology & Neuroinflammation. The results also showed significant additive 3-way interactions between the DRB1 * 15: 01 allele, BMI at age 20, and every aspect of Epstein-Barr virus (EBV) infection.
The study’s researchers wanted to find out if these MS risk factors had an additive interaction for inflammatory disease, and 3-way interactions between BMI at age 20, EBV infection, and human leukocyte antigen (HLA) DRB1 * Analyze 15: 01 allele.
They used data from the epidemiological study of multiple sclerosis (EIMS) and genes and environment in multiple sclerosis (GEMS) studies, 2 Swedish population-based case-control studies on environmental and genetic risk factors for MS. In the former case, newly diagnosed cases of MS were recruited from neurological clinics and compared with 2 randomly selected controls from the country’s national population register, the frequency corresponding in 5-year age groups, gender and area of residence. GEMS presented common cases of MS from the Swedish national MS registry, each of which was matched to a control in the same way as in EIMS.
Study researchers also included controls from the rheumatoid arthritis epidemiological survey, which was developed in the same way and with a similar study population as EIMS. Participants provided blood samples for genotyping and self-reported contraction of IM, height, and weight.
The combination of two risk factors, being overweight / obese at 20 years of age and a history of IM, synergistically increased the risk of MS five-fold. In contrast, non-overweight patients with a history of IM had a 90% increased risk of MS and those with overweight / obesity at the age of 20 years (BMI I ≥ 25 kg / m2) without a history of IM had a 40% increased MS risk. Risk.
BMI at the age of 20 and high EBNA-1 antibody levels showed a similar interaction even without a history of IM, which increased with increased EBNA-1 antibody levels.
There were interactions between DRB1 * 15:01 and overweight / obesity at the age of 20, between DRB1 * 15:01 and every aspect of the EBV infection, and between overweight / obesity at the age of 20 and every aspect of the EBV infection Directions. DRB1 * 15:01, BMI at the age of 20 and every aspect of the EBV infection (IM history or high EBNA-1 antibody levels) had significant 3-way interactions.
These results were important to both EIMS and GEMS when the researchers limited the analysis to subjects with complete data on HLA alleles and EBNA-1 antibody levels.
The limitations of the study included selection bias and recall bias in the studies as well as the risk of misclassification when subjects were divided into two with and without self-reported IM history.
The study researchers concluded, “The obese condition induces both chronic immune-mediated inflammation and the cellular immune response to infection, which may help explain our findings.” They added that their “data reinforce the importance of obesity intervention efforts in children and adolescents to reduce the incidence of MS”.
Disclosure: Several authors have stated links to the pharmaceutical industry. For a full list of the authors’ information, see the original reference.
Hedstrom AK, Brenner N., Butt J. et al. Overweight / obesity in young adulthood interacts with aspects of EBV infection in MS aetiology. Neurol Neuroimmunol Neuroinflamm. Published online on December 15, 2020. doi: 10.1212 / NXI.0000000000000912