Citations

ABSTRACT Among 9457 aquaporin‐4 (AQP4) immunoglobulin G‐positive patients, 2071 underwent autoimmune encephalitis antibody testing and 85 (4%) had coexisting antibodies, most commonly cerebrospinal fluid glial fibrillary acidic protein‐IgG and N‐methyl‐D‐aspartate receptor‐IgG, or serum high‐titer GAD65‐IgG. Compared with AQP4‐IgG positive neuromyelitis optica spectrum disorder controls, dual‐positive patients were younger and more frequently exhibited encephalopathy, psychiatric symptoms, seizures, ovarian teratomas, and deep gray matter, temporal lobe, or diencephalic MRI abnormalities. GAD65‐IgG‐positive patients developed stiff‐person syndrome. These findings define a distinct mixed glial‐neuronal autoimmune phenotype and support additional neural antibody testing in atypical AQP4‐IgG‐positive presentations.

Importance Myelin oligodendrocyte glycoprotein antibody–associated disease (MOGAD) lacks proven relapse-preventive therapies. While clinical trials are ongoing, safety data may be limited and approved drugs are costly. Studies of interleukin 6 receptor blocker (IL-6RB) in MOGAD are limited by small numbers and no comparative studies, contributing to low use. Objective To evaluate the impact of IL-6RB therapy on relapse rates in MOGAD and compare relapse frequency with intravenous immunoglobulin (IVIG). Design, Setting, and Participants This international, multicenter, retrospective cohort study (January 1, 2015, through December 31, 2025) included a historical IVIG-treated cohort of varying doses. The study took place across sites in North and South America (US, Canada, Mexico, Argentina, Brazil, Chile, Colombia, and Peru). Patients with MOGAD (n = 116, no excluded patients) who received at least 1 dose of an IL-6RB were included. These data were analyzed in January 2026. Exposures Tocilizumab or satralizumab. Main Outcomes and Measures Annualized relapse rate (ARR) during IL-6RB therapy, time to next relapse after treatment initiation, and adverse events. Outcomes were compared with the IVIG cohort using inverse probability of treatment weighting (IPTW) adjusted for age, sex, prior ARR, and concomitant therapies. Results A total of 116 patients with MOGAD (89% relapsing) receiving IL-6RB (tocilizumab, 104 [90%] and satralizumab, 12 [10%]) were included; overall, 60.3% were female, 39.7% were male, and 18% were younger than 18 years. The median (IQR) IL-6RB treatment follow-up was 1.4 (0.7-2.5) years and 23 relapses occurred during 241.8 person-years of IL-6RB therapy. The ARR decreased from 0.64 (95% CI, 0.58-0.70) for relapsing MOGAD before IL-6RB to 0.09 (95% CI, 0.06-0.14) during IL-6RB treatment (incidence rate ratio, 0.08; 95% CI, 0.04-0.16). Adverse events occurred in 58 patients (50%), most commonly mild infections, although 10 (9%) had severe infections. In the IVIG cohort (n = 59), 30 relapses occurred over 133.8 person-years (ARR, 0.22; 95% CI, 0.15-0.32). After IPTW, IL-6RB was associated with a lower hazard ratio (HR) than the group who underwent IVIG therapy less than 1 g/kg every 4 weeks (HR, 4.5; 95% CI, 2.0-9.8), with no significant difference vs the group who underwent IVIG 1 g/kg or more every 4 weeks (HR, 2.0; 95% CI, 0.8-4.5). Conclusions and Relevance In this multicenter observational cohort, IL-6RB use in MOGAD was associated with low relapse rates and a favorable safety profile, though severe infections occurred occasionally. Relapse rates were lower than the group who underwent IVIG less than 1 g/kg every 4 weeks but not significantly different from the group who underwent IVIG 1 g/kg or more every 4 weeks. This supports IL-6RB as a potential relapse-prevention therapy in MOGAD; the wide availability and relative affordability of tocilizumab may enable broad global use.

ABSTRACT Objective Little is known about shifting from pediatric to adult‐focused multiple sclerosis (MS) care. This study aims to explore transition of care and follow‐up in the US pediatric‐onset MS (POMS) population. Methods Surveys were distributed to 10 sites in the US Network of Pediatric MS Centers (US NPMSC) about transition‐of‐care practices. A cohort of POMS/clinically isolated syndrome (CIS) at 12 US NPMSC sites was analyzed. The primary comparison was between < 18 and ≥ 18‐years of age. The primary outcome was 1‐ and 2‐year lapse in last follow‐up visit, measured from last recorded database visit to data lock date or, if ≥ 18 years of age, up to 1 year after a patient reached their site's typical transition age, if earlier. Secondary outcomes were baseline factors associated with follow‐up lapse. The model was adjusted for preidentified confounders. Results Compared with < 18 years, age ≥ 18 was associated with greater hazard of 1‐ and 2‐year follow‐up lapse. In POMS/CIS, the estimated hazard was 1.61 for 1‐year lapse (95% confidence interval [CI] 1.32–1.97, p < 0.001) and 1.40 for 2‐year lapse (95% CI 1.11–1.76, p = 0.004). In POMS‐only, the estimated hazard was 1.70 for 1‐year lapse (95% CI 1.33–2.18, p < 0.001) and 1.49 for 2‐year lapse (95% CI 1.11–1.99, p = 0.007). Platform injectable disease‐modifying therapy was associated with greater and intravenous with lesser hazard of lapse in follow‐up, while MS was associated with lower hazard than CIS. Conclusion Variable transition‐of‐care practices and barriers were reported by major US POMS centers. Before typical transition age, age ≥ 18 was associated with greater hazard of 1‐ and 2‐year follow‐up lapse than < 18. Developing standardized, targeted transition‐of‐care practices in POMS may be important.

Background: Epstein–Barr virus (EBV) is a key environmental risk factor for multiple sclerosis (MS), and tonsils and adenoids serve as a primary viral reservoir. This study investigates the potential role of adenotonsillectomy in pediatric-onset multiple sclerosis (POMS) risk and relapse rate. Objectives: POMS participants and controls were recruited from 16 pediatric MS clinics between 1 November 2011 and 1 July 2017. Clinical and demographic information, including history of adenotonsillectomy, EBV serostatus, and HLA-DRB1*15:01:01 status, were collected. Multivariable logistic regression assessed the association between adenotonsillectomy and MS risk. In addition, negative binomial regression offset by follow-up time was used to assess the relationship between adenotonsillectomy and relapse rate in POMS participants with available follow-up data. Results: The case-control analysis included 359 POMS participants and 560 pediatric controls. Individuals with a history of adenotonsillectomy had a 63% increased odds of MS (adjusted odds ratio (OR) = 1.63, 95% confidence interval (CI) = 1.01–2.64, p = 0.046). Among the 239 POMS participants with available follow-up data, adenotonsillectomy was associated with a twofold increase in annualized relapse rate (adjusted incidence rate ratio (IRR) = 2.00, 95% CI = 1.15–3.48, p = 0.013). Conclusions: Prior adenotonsillectomy was associated with increased risk of MS and greater relapse rate in pediatric patients, suggesting a potential interplay between EBV, immune regulation, and MS pathogenesis.

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.

Objective To assess real‐world effectiveness of switching disease‐modifying therapy (DMT) in pediatric multiple sclerosis (MS) and clinically isolated syndrome (CIS) initially treated with platform injectables on disease activity. Methods Of 2615 pediatric‐onset demyelinating disease patients at 12 clinics in the United States (US) Network of Pediatric MS Centers, those with MS/CIS on initial therapy with a platform injectable who switched to another class of platform injectable, oral or infusion DMT were analyzed. Relapse rate was modeled with negative binomial regression, adjusted for preidentified confounders. Results A total of 212 children switched DMT before age 18 (67% female, 95% MS). Ninety‐three switched from injectable to injectable, 76 injectable to oral, and 43 injectable to infusion. Switchers to oral or infusion were older at onset (injectable 12.3 years, oral 13.5 years, and infusion 14.2 years) and switch (injectable 14.6 years, oral 16.0 years, and infusion 15.7 years). Switchers to infusion DMT were more likely to have enhancing lesions (injectable 45%, oral 28%, and infusion 67%). Compared to injectable (annualized relapse rate [ARR] = 0.88, 95% confidence interval [CI] = 0.52–1.48), relapse rates were lower for injectable to oral (ARR = 0.34, 95% CI = 0.20–0.57; rate ratio: 0.38, 95% CI = 0.21–0.69) and injectable to infusion (ARR = 0.18, 95% CI = 0.09–0.37; rate ratio: 0.21, 95% CI = 0.10–0.44) ( p < 0.001). Adjusted number needed to treat in person‐years to prevent 1 relapse with oral over injectable was 1.84 (95% CI = 1.03–8.69) and infusion over injectable 1.43 (95% CI = 1.00–3.88). Interpretation Switching from platform injectable to oral or infusion compared to other platform injectable DMT led to better disease control in pediatric MS. Long‐term safety data are required. ANN NEUROL 2026;99:715–729