Humoral response to Epstein-Barr virus in patients with multiple sclerosis treated with B cell depletion therapy

Background B cell depletion therapy is highly effective in relapsing-remitting multiple sclerosis (RRMS). However, the precise underlying mechanisms of action for its biological effects in MS have still not been clarified. Epstein-Barr virus (EBV) is a known risk factor for MS and seems to be a prerequisite for disease development. EBV resides latently in the memory B cells, and may not only increase the risk of developing MS, but also contribute to disease activity and disability progression. Therefore, the effects of B cell depletion in MS could be associated with the depletion of EBV-infected cells and the altered immune response to the virus. In this study, we investigate the impact of B cell depletion on the humoral immune response specific to EBV in patients with MS. Methods Newly diagnosed, treatment-naïve patients with RRMS were followed up to 18 months after initiation of B-cell depletion therapy in the Overlord-MS study, a phase III trial (NCT04578639). We analyzed serum sampled before treatment and after 3, 6, 12 and 18 months for immunoglobulin γ (IgG) against Epstein-Barr nuclear antigen 1 (EBNA1) and Epstein-Barr viral capsid antigen (VCA). We analyzed antibodies to cytomegalovirus (CMV) and total IgG in serum, as controls for viral and overall humoral immunity. The risk allele, HLA-DRB1*15:01, and the protective allele, HLA-A*02:01, were determined in all participants. In addition, polymerase chain reaction (PCR) for circulating EBV-DNA was performed in the first 156 samples drawn. The associations between time on B cell-depletion therapy and serum anti-EBV antibody levels were estimated using linear mixed-effects models. Results A total of 290 serum samples from 99 patients were available for analysis. After 6, 12 and 18 months, the EBNA1 IgG levels decreased by 12.7 % (95 % CI -18.8 to -6.60, p < 0.001), 12.1 % (95 % CI -19.8 to -3.7, p = 0.006) and 14.6 % (95 % CI to -25.3 to -2.4, p = 0.02) respectively, compared to baseline level. Carriers of the HLA-DRB1*15:01 allele had higher EBNA1 IgG levels at baseline (p = 0.02). The VCA IgG levels significantly increased by 13.7 % (95 % CI 9.4 to 18.1, p < 0.001) after 3 months, compared to baseline, and persisted at this level throughout the follow-up. CMV IgG levels decreased, but to a lesser extent than the decrease of EBNA1 IgG, and total IgG levels decreased during therapy. Circulating EBV-DNA was found in only three of 156 samples from 64 patients. Conclusions EBNA1 IgG levels decreased, while VCA IgG levels increased, during B cell depletion therapy. This supports the hypothesis that the mechanism of action for B cell depletion therapy might be mediated by effects on EBV infection, which, in turn, mitigate immune cross-reactivity and disease perpetuation.publishedVersio

Beta2-adrenoreceptor agonists and long-term risk of Parkinson's disease

Introduction There is limited information on how the association between Parkinson's disease and the use of beta2-adrenoreceptor (β2AR) agonists varies among groups of short-, long-, and ultra-long-acting β2AR agonists (SABA, LABA and ultraLABA). Methods In this prospective study of the Norwegian population, we estimated the incidence of Parkinson's disease according to exposure to β2AR agonists as a time-dependent variable by means of Cox regression. We adjusted for educational level, comorbidity and performed a sensitivity analysis excluding individuals with chronic obstructive pulmonary disease (COPD), all factors associated with smoking. Anticholinergics and corticosteroids as drugs with the same indication were analyzed for comparison. Results In the follow-up period from 2005 to 2019, 15,807 incident Parkinson's cases were identified. After adjustments for sex, education and age as the timescale, SABA (Hazard ratio (HR) = 0.84; 95%CI: 0.79, 0.89; p < 0.001), LABA (HR = 0.85; 95%CI: 0.81, 0.90; p < 0.001) and ultraLABA (HR = 0.6; 95%CI: 0.49, 0.73; p < 0.001) were all associated with a lower risk of Parkinson's disease. After exclusion of COPD patients, corticosteroids and anticholinergics were no longer inversely associated, whereas β2AR agonists remained associated. Conclusion Of drugs with the same indication of use, only β2AR agonists remained inversely associated with PD risk after all adjustments, with ultraLABA displaying the overall strongest association. Although the precision of the estimate is limited by the modest number of exposed PD cases without COPD, the association is intriguing and suggest that longer-acting, more lipophilic, and thus likely more brain-penetrant β2AR agonists could be prioritized for further studies.publishedVersio

The interplay between environmental risk factors for multiple sclerosis

Background: Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system whose etiology is unknown. While several genetic factors and environmental exposures, including low vitamin D, smoking, infectious mononucleosis (IM) and obesity, have been consistently associated with increased MS risk, they are unlikely to fully explain the individual disease risk. Further, little is known about the underlying mechanisms by which they may affect disease risk. Objective: The main objectives of this study were to examine how exposure to selected environmental factors in specific age periods was associated with MS risk and to disclose whether the associations varied between different populations using the same methodology. In detail, we sought 1) to examine how frequency of outdoor activity, as a proxy for sun exposure and vitamin D levels, in specific age periods from birth to disease onset was associated with MS risk, 2) to examine to which degree prior exposure to known environmental risk factors could explain the association between level of education and MS risk and 3) to examine how the interplay between smoking and IM affected MS risk in our study populations. Methods: We used data from the large multi-national population-based case-control study Environmental Risk Factors in MS (EnvIMS), which included participants from Norway, Italy, Serbia, Sweden and Canada. For the two first articles, data from Norway and Italy was available, while for the third article data from Sweden was also available. In total, this included 1904 patients and 3694 controls. In the countries included in our analyses, patients were recruited from regional or national MS registries, while four times as many age and sex frequency-matched controls were randomly selected from population registries. All patients had been diagnosed according to the McDonald or the Poser criteria, and had clinical onset within 10 years prior to data collection. All participants were older than 18 years at time of selection. Cases and controls in each country reported on prior exposure to selected environmental factors in specific age periods of life using an identical selfadministered questionnaire (EnvIMS-Q), which had been developed specifically for our study. For the current analyses, information on outdoor activity, sunscreen use, hair color, smoking, IM, body size, cod liver oil supplementation, fatty fish intake and level of education was used. The controls were randomly assigned an index age based on the distribution of age of onset among the cases and exposure after disease onset or index age was not considered exposure. The association between disease and exposure was estimated as odds ratios (OR) with 95% confidence intervals (95% CI) using logistic regression. All analyses were adjusted for age and sex. Results: In the first article, we found a significant inverse association between frequency of outdoor activity and MS risk in Norway and Italy. The magnitude of the association was strongest between age 16 and 18 in Norway (OR 1.83, 95% CI: 1.30- 2.59), and between birth and age 5 years in Italy (OR 1.56, 95% CI: 1.16-2.10). We observed seasonal differences in the association in Norway, whereas we observed a significant association for outdoor activity during summer, but not in the winter. For Italy, the association was similar for summer and winter. In addition, we found a significant association between sunscreen use and MS risk during childhood in Norway after accounting for outdoor activity (OR 1.67, 95% CI: 1.06-2.63). In the second article, we found an inverse association between level of education and MS risk in Norway (OR highest vs lowest level: 0.53, 95% CI: 0.41-0.68). The association remained significant after adjusting for smoking, IM, outdoor activity, cod liver oil, fatty fish consumption and body size. Further, the association remained similar after we excluded patients with early onset of disease, defined as onset before age 28. In the third article, we found a statistical significant negative multiplicative interaction between smoking and IM in the risk of MS. Among those who reported IM, we observed no increased disease risk associated with smoking. Similarly, the effect estimates for the association between IM and MS risk were considerably lower among ever-smokers compared to never smokers. The interaction was similar in Norway, Italy, and Sweden. Lastly, we observed similar results on when estimating the interaction on the additive scale, although they did not reach statistical significance. Conclusion: The findings of this study add to the evidence that vitamin D has a protective effect on MS risk, and indicate that adolescence is a sensitive period for exposure. Still, exposure earlier in life might also be of importance. Further, established risk factors cannot fully explain the association between level of education and MS risk in Norway, suggesting that currently unknown environmental exposures associated with lower level of education may be important for disease risk. Lastly, our findings indicate a competing antagonism between smoking and IM in the risk of MS, which suggests that the two risk factors operate on shared biological pathways

Level of education and multiple sclerosis risk after adjustment for known risk factors: The EnvIMS study

Background: Several recent studies have found a higher risk of multiple sclerosis (MS) among people with a low level of education. This has been suggested to reflect an effect of smoking and lower vitamin D status in the social class associated with lower levels of education. Objective: The objective of this paper is to investigate the association between level of education and MS risk adjusting for the known risk factors smoking, infectious mononucleosis, indicators of vitamin D levels and body size. Methods: Within the case-control study on Environmental Factors In MS (EnvIMS), 953 MS patients and 1717 healthy controls from Norway reported educational level and history of exposure to putative environmental risk factors. Results: Higher level of education were associated with decreased MS risk (p trend = 0.001) with an OR of 0.53 (95% CI 0.41–0.68) when comparing those with the highest and lowest level of education. This association was only moderately reduced after adjusting for known risk factors (OR 0.61, 95% CI 0.44–0.83). The estimates remained similar when cases with disease onset before age 28 were excluded. Conclusion: These findings suggest that factors related to lower socioeconomic status other than established risk factors are associated with MS risk

Timing of use of cod liver oil, a vitamin D source, and multiple sclerosis risk: The EnvIMS study.

Background: Low vitamin D levels have been associated with an increased risk of multiple sclerosis (MS), although it remains unknown whether this relationship varies by age. Objective: The objective of this paper is to investigate the association between vitamin D3 supplementation through cod liver oil at different postnatal ages and MS risk. Methods: In the Norwegian component of the multinational case-control study Environmental Factors In Multiple Sclerosis (EnvIMS), a total of 953 MS patients with maximum disease duration of 10 years and 1717 controls reported their cod liver oil use from childhood to adulthood. Results: Self-reported supplement use at ages 13–18 was associated with a reduced risk of MS (OR 0.67, 95% CI 0.52–0.86), whereas supplementation during childhood was not found to alter MS risk (OR 1.01, 95% CI 0.81–1.26), each compared to non-use during the respective period. An inverse association was found between MS risk and the dose of cod liver oil during adolescence, suggesting a dose-response relationship (p trend = 0.001) with the strongest effect for an estimated vitamin D3 intake of 600–800 IU/d (OR 0.46, 95% CI 0.31–0.70). Conclusions: These findings not only support the hypothesis relating to low vitamin D as a risk factor for MS, but further point to adolescence as an important susceptibility period for adult-onset MS

Physical activity is associated with a decreased multiple sclerosis risk: The EnvIMS study

BACKGROUND: The lifestyle factors smoking and obesity have been associated with the risk of multiple sclerosis (MS). Physical activity (PA) may also be of importance. OBJECTIVE: To examine the association between PA and MS risk in Italy, Norway, and Sweden and to evaluate the possible influence by established risk factors. METHODS: In this case-control study, 1904 cases and 3694 controls were asked to report their average weekly amounts of light and vigorous PA during adolescence on a scale ranging from none to more than 3 hours activity. We used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) and adjusted for potential confounders. RESULTS: Vigorous PA was inversely associated with MS risk in the pooled analysis ( p-trend < 0.001) with an age- and sex-adjusted OR of 0.74 (95% CI: 0.63-0.87) when comparing the highest and lowest levels. Adjusting for outdoor activity, infectious mononucleosis, body size, and smoking yielded similar results. The association was present in all countries and was not affected by exclusion of patients with early disease onset. Light PA was not associated with the risk of MS. CONCLUSION: Our findings suggest that vigorous PA can modify the risk of developing MS independent of established risk factors

Intake of carbohydrates and SFA and risk of CHD in middle-age adults: The Hordaland Health Study (HUSK)

Objective: Limiting SFA intake may minimise the risk of CHD. However, such reduction often leads to increased intake of carbohydrates. We aimed to evaluate associations and the interplay of carbohydrate and SFA intake on CHD risk. Design: Prospective cohort study. Setting: We followed participants in the Hordaland Health Study, Norway from 1997–1999 through 2009. Information on carbohydrate and SFA intake was obtained from a FFQ and analysed as continuous and categorical (quartiles) variables. Multivariable Cox regression estimated hazard ratios (HR) and 95 % CI. Theoretical substitution analyses modelled the substitution of carbohydrates with other nutrients. CHD was defined as fatal or non-fatal CHD (ICD9 codes 410–414 and ICD10 codes I20–I25). Participants: 2995 men and women, aged 46–49 years. Results: Adjusting for age, sex, energy intake, physical activity and smoking, SFA was associated with lower risk (HRQ4 v. Q1 0·44, 95 % CI 0·26, 0·76, Ptrend = 0·002). For carbohydrates, the opposite pattern was observed (HRQ4 v. Q1 2·10, 95 % CI 1·22, 3·63, Ptrend = 0·003). SFA from cheese was associated with lower CHD risk (HRQ4 v. Q1 0·44, 95 % CI 0·24, 0·83, Ptrend = 0·006), while there were no associations between SFA from other food items and CHD. A 5 E% substitution of carbohydrates with total fat, but not SFA, was associated with lower CHD risk (HR 0·75, 95 % CI 0·62, 0·90). Conclusions: Higher intake of predominantly high glycaemic carbohydrates and lower intake of SFA, specifically lower intake from cheese, were associated with higher CHD risk. Substituting carbohydrates with total fat, but not SFA, was associated with significantly lower risk of CHD

Neurofilament light chain predicts disease activity in relapsing-remitting MS

Objective: To investigate whether serum neurofilament light chain (NF-L) and chitinase 3-like 1 (CHI3L1) predict disease activity in relapsing-remitting MS (RRMS). Methods: A cohort of 85 patients with RRMS were followed for 2 years (6 months without disease-modifying treatment and 18 months with interferon-beta 1a [IFNB-1a]). Expanded Disability Status Scale was scored at baseline and every 6 months thereafter. MRI was performed at baseline and monthly for 9 months and then at months 12 and 24. Serum samples were collected at baseline and months 3, 6, 12, and 24. We analyzed the serum levels of NF-L using a single-molecule array assay and CHI3L1 by ELISA and estimated the association with clinical and MRI disease activity using mixed-effects models. Results: NF-L levels were significantly higher in patients with new T1 gadolinium-enhancing lesions (37.3 pg/mL, interquartile range [IQR] 25.9–52.4) and new T2 lesions (37.3 pg/mL, IQR 25.1–48.5) compared with those without (28.0 pg/mL, IQR 21.9–36.4, β = 1.258, p < 0.001 and 27.7 pg/mL, IQR 21.8–35.1, β = 1.251, p < 0.001, respectively). NF-L levels were associated with the presence of T1 gadolinium-enhanced lesions up to 2 months before (p < 0.001) and 1 month after (p = 0.009) the time of biomarker measurement. NF-L levels fell after initiation of IFNB-1a treatment (p < 0.001). Changes in CHI3L1 were not associated with clinical or MRI disease activity or interferon-beta 1a treatment. Conclusion: Serum NF-L could be a promising biomarker for subclinical MRI activity and treatment response in RRMS. In clinically stable patients, serum NF-L may offer an alternative to MRI monitoring for subclinical disease activity

Intake of carbohydrates and SFA and risk of CHD in middle-age adults: The Hordaland Health Study (HUSK)

Objective: Limiting SFA intake may minimise the risk of CHD. However, such reduction often leads to increased intake of carbohydrates. We aimed to evaluate associations and the interplay of carbohydrate and SFA intake on CHD risk. Design: Prospective cohort study. Setting: We followed participants in the Hordaland Health Study, Norway from 1997–1999 through 2009. Information on carbohydrate and SFA intake was obtained from a FFQ and analysed as continuous and categorical (quartiles) variables. Multivariable Cox regression estimated hazard ratios (HR) and 95 % CI. Theoretical substitution analyses modelled the substitution of carbohydrates with other nutrients. CHD was defined as fatal or non-fatal CHD (ICD9 codes 410–414 and ICD10 codes I20–I25). Participants: 2995 men and women, aged 46–49 years. Results: Adjusting for age, sex, energy intake, physical activity and smoking, SFA was associated with lower risk (HRQ4 v. Q1 0·44, 95 % CI 0·26, 0·76, Ptrend = 0·002). For carbohydrates, the opposite pattern was observed (HRQ4 v. Q1 2·10, 95 % CI 1·22, 3·63, Ptrend = 0·003). SFA from cheese was associated with lower CHD risk (HRQ4 v. Q1 0·44, 95 % CI 0·24, 0·83, Ptrend = 0·006), while there were no associations between SFA from other food items and CHD. A 5 E% substitution of carbohydrates with total fat, but not SFA, was associated with lower CHD risk (HR 0·75, 95 % CI 0·62, 0·90). Conclusions: Higher intake of predominantly high glycaemic carbohydrates and lower intake of SFA, specifically lower intake from cheese, were associated with higher CHD risk. Substituting carbohydrates with total fat, but not SFA, was associated with significantly lower risk of CHD