BACKGROUND AND OBJECTIVES:Invasive procedures may delay the diagnostic process in multiple sclerosis (MS). We investigated the added value of serum neurofilament light chain (sNfL), glial fibrillary acidic protein (sGFAP), chitinase-3-like 1 (sCHI3L1), and the immune responses to the Epstein-Barr virus-encoded nuclear antigen 1 to current MS diagnostic criteria. METHODS:In this multicentric study, we selected patients from 2 prospective cohorts presenting a clinically isolated syndrome (CIS). Patients were classified as (1) not presenting dissemination in space (DIS) nor dissemination in time (DIT) (noDIS and noDIT); (2) presenting DIS without DIT (DIS and noDIT); and (3) presenting both (DIS and DIT), which were used as a reference. sNfL, sGFAP, and sCHI3L1 levels were measured with single-molecule array immunoassays and EBNA1-specific IgG levels with ELISA. Biomarker levels were compared between groups using linear regression models. Receiver operating characteristic curve analyses and Youden Index were used to determine cutoff values associated with MS diagnosis during follow-up. RESULTS:We included 181 patients (66.3% females, mean [SD] age of 35.0 [9.7] years). At baseline, 25 (13.8%) were classified as noDIS and noDIT, 62 (34.3%) as DIS and noDIT, and 94 (51.9%) as DIS and DIT. Only sNfL Z-scores discriminated between groups (DIS and DIT vs DIS and noDIT [p = 0.002], DIS and DIT vs noDIS and noDIT [p < 0.001], and DIS and noDIT vs noDIS and noDIT [p = 0.026]). In noDIS and noDIT patients (median interquartile range [IQR] follow-up of 8.1 [5.0-11.7] years), high sNfL Z-scores best predicted MS diagnosis (specificity [SP] and 95% CI of 93.3% [68.1-99.8] and positive predictive value [PPV] of 87.5% [47.3-99.7]). Among DIS and noDIT patients (median [IQR] follow-up of 6.8 [4.0-9.1] years), high sNfL Z-scores best predicted MS diagnosis (SP of 80% [28.4-99.5] and PPV of 97.3% [85.8-99.9]) without considering oligoclonal band (OB) status. In the subset of patients of this group with negative OBs, a combination of high sNfL Z-scores and sGFAP levels predicted MS diagnosis (SP of 100% [39.8-100] and PPV of 100% [54.1-100]). DISCUSSION:These results suggest that sNfL and sGFAP may be incorporated in particular scenarios to diagnose MS in patients with CIS not fulfilling current diagnostic criteria.

Background and ObjectivesThe role of the complement system in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is not completely understood, and studies exploring its potential utility for diagnosis and prognosis are lacking. We aimed to investigate the value of complement factors (CFs) as diagnostic and prognostic biomarkers in patients with MOGAD.MethodsMulticentric retrospective cohort study including patients with MOGAD, multiple sclerosis (MS) and aquaporin-4 seropositive neuromyelitis optica spectrum disorder (AQP4-NMOSD) with available paired serum and CSF samples. A panel of CFs were measured by multiplex ELISA, and the levels were compared between the 3 conditions. Univariable and multivariable analyses were performed to evaluate the association between levels of CFs and relapse and disability outcomes in MOGAD patients.ResultsNinety-four patients (MOGAD, n = 60; MS, n = 18; AQP4-NMOSD, n = 16) were included. Mean (SD) age at sampling was 39.4 (16.7), 40.7 (7.0), and 43.3 (21.0), respectively. Female were predominant, especially in AQP4-NMOSD (88%). Combination of the serum levels of C3a, C4a, and C3a/C3 ratio showed excellent potential to discriminate MOGAD from patients with MS (area under the curve [AUC] [95% CI] 0.95 [0.90-0.99]) and from AQP4-NMOSD (AUC 0.88 [0.76-1.00]). In patients with MOGAD, CSF levels of CFs of the classical/lectin pathway influenced relapse-related outcomes, and lower C4 levels were associated with higher number of relapses during follow-up (incidence rate ratio [95% CI] 0.88 [0.78-0.99]; p = 0.04 in multivariable analysis), and a high C4a/C4 ratio was associated with increased risk of second relapse during the first year (hazard ratio [95% CI] 3.68 [1.26-10.78]; p = 0.02 in multivariable analysis). Time to second relapse was shorter in patients with MOGAD with a high CSF C4a/C4 ratio (log-rank p = 0.01). CSF levels of the membrane attack complex SC5b9 influenced disability-related outcomes, and baseline CSF SC5b9 levels were higher in patients who reached the final Expanded Disability Status Scale (EDSS) >= 3.0 (p = 0.002), and elevated SC5b9 levels were associated with increased risk of reaching EDSS >= 3.0 (odds ratio [95% CI] 1.79 [1.16-3.67]; p = 0.04 in multivariable analyses).DiscussionOur results suggest that serum and CSF levels of CFs have diagnostic and prognostic value respectively in patients with MOGAD. These findings support the use of complement inhibitors as a therapeutic approach in these patients.

BACKGROUND:It is essential to exclude alternative diagnoses to diagnose multiple sclerosis (MS). However, detailed descriptions of alternative diagnoses in patients with suspected MS presenting with clinically isolated syndrome (CIS) are limited. OBJECTIVES:To describe alternative diagnoses in patients presenting with CIS suggestive of MS. METHODS:We conducted a descriptive analysis of patients from the Barcelona CIS cohort including subjects under 50 years of age with a CIS suggestive of MS but later diagnosed with conditions other than MS. We collected clinical, biological, and radiological data, and described the alternative etiologies identified. RESULTS:Among 1468 patients in the Barcelona CIS cohort, 100 (6.8%) were diagnosed with an alternative condition. The most common neurological syndrome was optic neuritis (43.0%). Four patients (4.0%) had inflammatory-demyelinating lesions in at least two typical MS topographies on baseline magnetic resonance imaging (MRI), and 2 (2.0%) met the 2017 McDonald MS criteria. The most common etiologies were immune-mediated diseases (42.0%), especially MOGAD, followed by functional neurological disorders (15.0%) and vascular disease (10.0%). CONCLUSION:The range of alternative diagnoses encountered during the MS diagnostic process highlights the need to rule out better explanations than MS. However, current MS diagnostic criteria effectively identify patients without MS in this context.

BACKGROUND AND OBJECTIVES:Emerging concepts in the early detection of multiple sclerosis (MS) progression reveal that disability accumulation can start early in the disease course. Aging in MS is increasingly recognized as a key factor for disease progression and disability accrual. We evaluate the prognostic impact of age in a cohort of patients experiencing a first demyelinating event (FDE), using a variety of disability outcomes, including some not previously assessed in age-specific studies. METHODS:Patients aged 18-50 years, assessed within 3 months from the FDE, were prospectively included since 1994 and categorized into 3 age groups: 18-29, 30-39, and 40-50 years. Relapse-associated worsening (RAW) at FDE, annualized relapse rate, and EDSS trajectories during follow-up were compared across age groups. Cox regression analyses adjusted for sex, comorbidities, and time exposed to very high-efficacy drugs were performed to assess the risk of achieving the following outcomes: time to reach McDonald 2017 criteria, first relapse, recurrent RAW, >2 new T2 brain lesions/year, first progression independent of relapse activity (PIRA), confirmed disability accumulation (CDA), and confirmed EDSS score 3.0. Patient-reported outcome measures were also analyzed. RESULTS:A total of 1,170 patients were included (median age 32 years; 69% female). The 40-50 group had a higher proportion of RAW at FDE (34% vs 25% and 29%; p = 0.031) and less time exposed to very high-efficacy treatments (p < 0.001) than the 30-39 and 18-29 groups, respectively. EDSS trajectories in the 40-50 group displayed a greater annual increase in the EDSS score compared with the 18-29 group (β 0.019 [95% CI 0.0001; 0.0387]). Cox analyses (HR; 95% CI) showed that the 40-50 group was at lower risk to reach McDonald 2017 criteria (0.80; 0.67-0.96), first relapse (0.59; 0.47-0.74), recurrent RAW (0.51; 0.31-0.86), or >2 new T2 brain lesions/year (0.39; 0.30-0.52), but at a higher risk of CDA (1.49; 1.16-1.97), PIRA (2.48; 1.88-3.27), and EDSS score 3.0 (1.50; 1.05-2.12), than the 18-29 group. Different functional and well-being variables were more affected in the 40-50 group, compared with 30-39 and 18-29 groups (p values< 0.05). DISCUSSION:Patients with a FDE at 40-50 years exhibit less inflammatory outcomes compared with younger patients and reach outcomes more closely related to neurodegeneration despite the lower disease activity.

Background: Limited data exist regarding treatment response prediction to oral disease-modifying therapies (DMTs) in multiple sclerosis (MS). Objectives: We assessed the capacity of available scoring systems to anticipate disease activity parameters in naïve relapsing–remitting MS (RRMS) patients initiating daily oral DMTs, hypothesizing that they exhibit different predictive potentials. Methods: We conducted a retrospective study and applied the Rio Score (RS), modified Rio Score (mRS), and MAGNIMS Score 12 months after DMT initiation. At 36 months, we examined their ability to predict evidence of disease activity (EDA) components and treatment failure by logistic regression analysis. Results: Notably, 218 patients (62.4% females) initiating dimethyl fumarate, teriflunomide, and fingolimod were included. At 36 months, the RS high-risk group predicted evidence of clinical activity (odds ratio (OR) 10 [2.7–36.9]) and treatment failure (OR 10.6 [3.4–32.5]) but did not predict radiological activity (OR 1.9 [0.7–5]). The mRS non-responders group did not predict EDA and treatment failure. RS, mRS, and MAGNIMS 0 categories showed significantly lower EDA and treatment failure than the remainder. Conclusion: Scoring systems present different predictive abilities for disease activity parameters at 36 months in MS patients initiating daily oral therapies, warranting further adjustments (i.e. introduction of fluid biomarkers) to depict disease activity status fully.

Background and Objectives We aimed to assess the presence of retinal neurodegeneration independent of optic neuritis (ON) in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to investigate the development of trans-synaptic anterograde degeneration in these patients after ON. Methods Cross-sectional, retrospective study of 34 adult patients with MOGAD and 23 healthy controls (HC). Clinical, optical coherence tomography (OCT), and MRI data were collected. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell inner plexiform layer (GCIPL) were obtained using Heidelberg Spectralis. FreeSurfer7 was used to obtain the lateral geniculate nucleus (LGN), occipital volume fractions (to total estimated intracranial volume), and occipital cortical thickness. For the anterior visual pathway, the analysis was conducted using eyes, classified based on the history of ON (Eye-ON and Eye-NON) and compared with Eye-HC. The analysis of OCT and brain volumetric measures was conducted comparing MOGAD-ON, MOGAD-NON, and HC groups. The analysis of covariance with a Bonferroni-adjusted post hoc test was used to test differences between groups and linear regression analysis to evaluate OCT/MRI associations; age and sex were considered as covariates. Results 24 (70.5%) patients had a prior ON. Median pRNFL and GCIPL thickness (um) was significantly reduced in Eye-ON vs EyeNON and HC (pRNFL: 69.4 (17.3), 89.6 (13.7), 98.2 (11.7), p < 0.001; GCIPL: 55.8 (8.7), 67.39 (8.7), 72.6 (4.5), p < 0.001). pRNFL and GCIPL thickness had a negative correlation with the number of ON episodes (p = 0.025 and p = 0.031, respectively). LGN volume fraction was significantly lower in patients with MOGAD-ON than in HC (0.33 (0.05) vs 0.39 (0.04), p = 0.002). The occipital cortical thickness was lower in MOGAD-ON compared with MOGAD-NON and HC (p = 0.010). In patients with MOGAD-ON, pRNFL correlated with LGN volume (p = 0.006), occipital thickness (p = 0.002), and the medial occipital cortex (p = 0.002), but not the lateral occipital lobe. Discussion Compared with HC, MOGAD-ON exhibits reduced retinal thickness, primarily influenced by the presence and the number of prior ON episodes. Moreover, MOGAD-ON demonstrates significant atrophy in the retinal, subcortical, and cortical regions of the visual pathway, distinguishing them from MOGAD-NON and HC. These findings suggest that in patients with MOGAD neurodegeneration is tightly correlated with damage to the involved pathway.

OBJECTIVE:The 2017 McDonald criteria continued the separation of diagnostic criteria for relapsing-remitting multiple sclerosis (RRMS) and primary progressive MS (PPMS) for historical, rather than biological, reasons. We aimed to explore the feasibility of a single, unified set of diagnostic criteria when applied to patients with suspected PPMS. METHODS:We retrospectively identified patients evaluated for suspected PPMS at 5 European centers. The 2017 McDonald PPMS criteria was the gold standard against which the 2017 McDonald RRMS dissemination in space (DIS) and dissemination in time criteria were evaluated. We also investigated modified RRMS DIS criteria, including: (i) optic nerve lesions; (ii) ≥2 spinal cord lesions; and (iii) higher fulfilment of DIS criteria alone (lesions in ≥3 regions) without dissemination in time/positive cerebrospinal fluid, for a diagnosis of PPMS. RESULTS:A total of 282 patients were diagnosed with PPMS using the 2017 McDonald criteria, and 40 with alternate disorders. The 2017 McDonald RRMS DIS criteria and the modified DIS criteria including the optic nerve or ≥2 spinal cord lesions performed well in PPMS diagnosis when combined with dissemination in time/positive cerebrospinal fluid (sensitivity 92.9-95.4%, specificity 95%, accuracy 93.2-95.3%). A diagnosis of PPMS based on high fulfillment of modified RRMS DIS criteria had high specificity, but low sensitivity. A diagnostic algorithm applicable to patients evaluated for suspected MS is proposed. INTERPRETATION:The 2017 McDonald RRMS criteria and modifications to DIS criteria, currently under consideration, performed well in PPMS diagnosis. Forthcoming revisions to the McDonald criteria should consider a single, unified set of diagnostic criteria for MS. ANN NEUROL 2025;97:571-582.

Background: Organizing pneumonia (OP), an interstitial lung disease, has been observed in patients with inflammatory demyelinating diseases (IDDs) treated with anti-CD20, particularly after COVID-19, but data are limited. Aim: To provide a detailed characterization of COVID-19-associated OP in IDD patients treated with anti-CD20. Methods: Bi-centric retrospective cohort study including patients with multiple sclerosis (MS), aquaporin-4-positive neuromyelitis optica spectrum disorder (AQP4 + NMOSD), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) who received anti-CD20 and were diagnosed with COVID-19-associated OP between March 2020 and October 2023. Results: Nineteen patients were included (mean age 46.8 years; 52.6% female; 63% rituximab, 37% ocrelizumab). Sixteen had MS, two MOGAD, and one AQP4 + NMOSD. Intermittent fever was the predominant symptom. Hospitalization occurred in all but one patient, without fatalities. Chest CT consistently showed OP patterns. Thirteen patients had positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) PCR in bronchoalveolar lavage. Treatments included corticosteroids, antivirals, monoclonal antibodies, and convalescent plasma. Fourteen patients postponed infusions; nine resumed post-recovery (median 11.9 months), two switched due to hypogammaglobulinemia, and three stopped. After a mean follow-up of 1.5 years, lung abnormalities and clinical manifestations resolved in 18 patients; however, 13 experienced long-COVID. Conclusions: In anti-CD20-treated patients with recurrent fever and distinctive CT features, COVID-19-associated OP should be considered.