Tillema, Jan-Mendelt

Background Increased chronological age correlates with reduced relapse rates and increased disability in multiple sclerosis (MS). Biological age may better capture ageing’s impact on MS and might accelerate due to MS itself. Establishing accelerated biological ageing in adults is complicated by normal ageing and comorbidities. Telomere length, a well-recognised biological ageing marker, is shortened in adults with MS and associated with disability. Demonstrating accelerated biological ageing in paediatric-onset MS (POMS) would strengthen the hypothesis that MS drives premature biological ageing. This study aimed to determine if telomere length differs in POMS compared to age-similar healthy controls. Methods We performed a cross-sectional case-control study of whole blood samples and clinical data from The US Network of Pediatric MS Centers. Real-time quantitative PCR measured telomere length, expressed as a telomere to somatic DNA ratio (T/S ratio). T/S ratio was compared between cases and age-similar healthy controls using multivariate regression analysis adjusting for chronological age, sex, race, ethnicity, tobacco exposure, socioeconomic status and body mass index. Results We analysed 300 POMS cases and 200 controls. The unadjusted mean T/S ratios were 1.66 (SD 0.32) for cases and 1.71 (SD 0.29) for controls (mean difference –0.05, 95% CI –0.10 to 0.01, p=0.08). After adjusting for key covariables with face validity, POMS participants had a mean 0.086 shorter T/S ratio than controls (95% CI 0.015 to 0.157, p=0.018). Conclusions POMS participants demonstrated shorter telomeres than age-similar controls in a multivariable model adjusting for sociodemographic variables, suggesting that MS may contribute to accelerated biological ageing.

Background: Age is the strongest factor determining disease expression in multiple sclerosis (MS). We previously demonstrated biological age acceleration in pediatric-onset MS (POMS) compared to controls with both epigenetic clocks (DNAm) and telomere length (TL). It is unknown whether these markers report overlapping or distinct aging-related processes. Objectives: To determine the correlation between DNAm and TL aging markers. Methods: We conducted a cross-sectional case–control study within the US Network of Pediatric MS Centers. We calculated age acceleration residuals for the Horvath, Hannum, PhenoAge, and GrimAge epigenetic clocks and measured TL from whole blood samples to estimate telomere to somatic DNA ratios (T/S ratio). We employed multivariable analysis of covariance to assess the correlation between DNAm estimates and TL. Results: We analyzed biological ages in 270 participants (125 POMS, mean 15.7 years; 145 controls, mean 15.3 years). There were moderate correlations among the different DNAm clocks, but no correlations between DNAm clocks and TL in pooled analyses. In a stratified analysis, only the control group showed a modest correlation between TL and PhenoAge clock ( r = 0.2, p = 0.06). Conclusions: DNAm did not correlate with TL in this sample of POMS and controls, suggesting that these biomarkers may capture complementary and non-overlapping elements of aging-related biology.

This study evaluated the efficacy of the multiple sclerosis disease-modifying therapies, intramuscular interferon beta-1a (Avonex) and subcutaneous peginterferon beta-1a (Plegridy), using data from the United States Network of Pediatric Multiple Sclerosis Centers. In this retrospective analysis, 154 patients with multiple sclerosis were included who were treated with Avonex (n = 130), Plegridy (n = 23), or both treatments (n = 1) before the age of 18 years. After 3 months’ sustained use acclimation (“wash-in”), the probability of being relapse-free during the first year was 68.3% for Avonex-treated patients and 69.9% for Plegridy-treated patients; annualized relapse rates were 0.50 and 0.59, respectively. Both disease-modifying therapies demonstrated efficacy similar to that reported in adult populations. Despite the lack of formal approval for pediatric multiple sclerosis, these outcomes indicate that patients may benefit from treatment with Avonex or Plegridy. Understanding efficacy of specific disease-modifying therapies in pediatric multiple sclerosis is essential to making informed treatment decisions.

Background Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and multiple sclerosis (MS) have both overlapping and distinct MRI lesion features, which vary with imaging timing. This study identified distinguishing MRI characteristics using paired MRIs at clinical attack and remission. Methods We retrospectively identified Mayo Clinic patients with MOGAD and MS that: (1) fulfilled respective diagnostic criteria; (2) had paired attack (≤30 days) and remission MRI scans (≥12 months) without interval attacks. MRIs were compared between groups for key features. Results We included 43 patients with MOGAD (median age 31 years (range, 3–67); 63% female) and 49 patients with MS (median age 39 years (range, 17–65); 65% female). Resolution of at least one T2-lesion differentiated MOGAD from MS (sensitivity, (95% CI 77% to 100%), specificity, (95% CI 86% to 99%); Youden’s index (YI)=0.90). Resolution of at least two T2-lesions indicated MOGAD (sensitivity 62% (95% CI 41% to 79%); specificity, 100% (95% CI 94% to 100%); YI=0.62). MOGAD patients were more likely to have normal MRI scans at follow-up compared with MS (brain 14/44 (32%) vs 0/60 (0%), p<0.001; spine 21/27 (78%) vs 7/36 (19%), p<0.001). In addition, the presence of T1-hypointense, ovoid periventricular T2, and enhancing lesions were more common in MS versus MOGAD at attack and remission and in the spine, longitudinally extensive T2 lesions were more common in MOGAD attacks (8/27 (30%)). Conclusion Paired MRI at attack and remission revealed distinctive characteristics of MOGAD and MS, with greater diagnostic value at remission driven by the discriminating power of T2-lesion resolution. In MOGAD patients with initial parenchymal involvement, a 1-year follow-up MRI may aid diagnosis and serve as a new baseline.

Background and Objectives The genetic basis of adult-onset multiple sclerosis (MS) is well-studied, but less is known about pediatric-onset MS (pedMS), comprising approximately 5% of all MS onsets. Mendelian randomization (MR) studies have demonstrated evidence for a causal association between MS and both 25-hydroxyvitamin D [25(OH)D] serum levels and genetic variation related to vitamin D receptor (VDR) binding. The objective was to identify whether VDR binding variants (VDR-BVs) previously implicated in adult-onset MS were associated with pedMS using genetic instrumental variables (GIVs). Methods Using previously identified VDR-BVs to construct individual GIVs with two-sample MR, we investigated associations with pedMS in 725 cases and 592 controls of European ancestry from the US Network of Pediatric MS Centers. Associations between each VDR-BV and pedMS were estimated using logistic regression adjusting for the first three genome-wide principal components. A significant interaction between a VDR-BV and 25(OH)D GIV provided evidence for a causal association unbiased by pleiotropy. Results One VDR-BV, rs2531804, previously associated with adult-onset MS, was also significantly associated with pedMS after multiple testing correction. Discussion This study is the first to use VDR-BVs from previous MR studies to demonstrate causal differences in VDR binding at a locus contributing to pedMS susceptibility.