BACKGROUND:Multiple Sclerosis (MS) is a chronic autoimmune disease causing central nervous system damage. Relapsing-remitting MS (RRMS) is the most common type. Disability in MS can result from relapse-associated worsening (RAW) or progression independent of relapse activity (PIRA), impacting quality of life. The Expanded Disability Status Scale (EDSS) is commonly used but has limitations. The Multiple Sclerosis Functional Composite (MSFC) improves progression detection sensitivity. OBJECTIVE:To analyze disability progression in a subgroup of RRMS patients (EDSS 3.0-6.5) and compare EDSS-Plus (EDSS, T25FW, and 9HPT) and EDSS-Plus with cognition (EDSS-Plus cog) to EDSS in assessing disease progression. METHODOLOGY:An 18-month prospective study in Argentina involved RRMS patients meeting the 2017 McDonald criteria and an EDSS between 3.0 and 6.5 at baseline. Patients received standard care and were assessed using EDSS, T25FW, 9HPT, and SDMT. Progression was defined as a ≥ 1.0-point increase in EDSS (baseline ≤5.5) or ≥0.5-point increase (baseline ≥6.0) over 24 weeks. RESULTS:EDSS-Plus and EDSS-Plus cog identified more progressors than EDSS, especially in patients with higher baseline disability (EDSS >4). Progression rates were 14 % for EDSS, 22.17 % for EDSS-Plus, and 25.33 % for EDSS-Plus cog. Progressors showed higher fatigue, depression, and anxiety scores. CONCLUSION:EDSS-Plus and EDSS-Plus cog are more sensitive than EDSS in detecting disability progression in RRMS patients, particularly those with higher baseline disability. However, this increase in detected progression events reflects the broader assessment criteria rather than necessarily indicating greater accuracy in identifying true disease progression.

BACKGROUND:Prognostic machine learning research in multiple sclerosis has been mainly focusing on black-box models predicting whether a patients' disability will progress in a fixed number of years. However, as this is a binary yes/no question, it cannot take individual disease severity into account. Therefore, in this work we propose to model the time to disease progression instead. Additionally, we use explainable machine learning techniques to make the model outputs more interpretable. METHODS:A preprocessed subset of 29,201 patients of the international data registry MSBase was used. Disability was assessed in terms of the Expanded Disability Status Scale (EDSS). We predict the time to significant and confirmed disability progression using random survival forests, a machine learning model for survival analysis. Performance is evaluated on a time-dependent area under the receiver operating characteristic and the precision-recall curves. Importantly, predictions are then explained using SHAP and Bellatrex, two explainability toolboxes, and lead to both global (population-wide) as well as local (patient visit-specific) insights. RESULTS:On the task of predicting progression in 2 years, the random survival forest achieves state-of-the-art performance, comparable to previous work employing a random forest. However, here the random survival forest has the added advantage of being able to predict progression over a longer time horizon, with AUROC >60% for the first 10 years after baseline. Explainability techniques further validated the model by extracting clinically valid insights from the predictions made by the model. For example, a clear decline in the per-visit probability of progression is observed in more recent years since 2012, likely reflecting globally increasing use of more effective MS therapies. CONCLUSION:The binary classification models found in the literature can be extended to a time-to-event setting without loss of performance, thus allowing a more comprehensive prediction of patient prognosis. Furthermore, explainability techniques proved to be key to reach a better understanding of the model and increase validation of its behaviour.

Importance:Progression independent of relapse activity (PIRA) is a significant contributor to long-term disability accumulation in relapsing-remitting multiple sclerosis (MS). Prior studies have used varying PIRA definitions, hampering the comparability of study results. Objective:To compare various definitions of PIRA. Design, Setting, and Participants:This cohort study involved a retrospective analysis of prospectively collected data from the MSBase registry from July 2004 to July 2023. The participants were patients with MS from 186 centers across 43 countries who had clinically definite relapsing-remitting MS, a complete minimal dataset, and 3 or more documented Expanded Disability Status Scale (EDSS) assessments. Exposure:Three-hundred sixty definitions of PIRA as combinations of the following criteria: baseline disability (fixed baseline with re-baselining after PIRA, or plus re-baselining after relapses, or plus re-baselining after improvements), minimum confirmation period (6, 12, or 24 months), confirmation magnitude (EDSS score at/above worsening score or at/above threshold compared with baseline), freedom from relapse at EDSS score worsening (90 days prior, 90 days prior and 30 days after, 180 days prior and after, since previous EDSS assessment, or since baseline), and freedom from relapse at confirmation (30 days prior, 90 days prior, 30 days before and after, or between worsening and confirmation). Main Outcome and Measure:For each definition, we quantified PIRA incidence and persistence (ie, absence of a 3-month confirmed EDSS improvement over ≥5 years). Results:Among 87 239 patients with MS, 33 303 patients fulfilled the inclusion criteria; 24 152 (72.5%) were female and 9151 (27.5%) were male. At the first visits, the mean (SD) age was 36.4 (10.9) years; 28 052 patients (84.2%) had relapsing-remitting MS, and the median (IQR) EDSS score was 2.0 (1.0-3.0). Participants had a mean (SD) 15.1 (11.9) visits over 8.9 (5.2) years. PIRA incidence ranged from 0.141 to 0.658 events per decade and persistence from 0.753 to 0.919, depending on the definition. In particular, the baseline and confirmation period influenced PIRA detection. The following definition yielded balanced incidence and persistence: a significant disability worsening compared with a baseline (reset after each PIRA event, relapse, and EDSS score improvement), in absence of relapses since the last EDSS assessment, confirmed with EDSS scores (not preceded by relapses within 30 days) that remained above the worsening threshold for at least 12 months. Conclusion and Relevance:Incidence and persistence of PIRA are determined by the definition used. The proposed standardized definition aims to enhance comparability among studies.

IntroductionThere are no reports in LATAM related to longitudinal humoral and cellular response to adenovirus based COVID-19 vaccines in people with Multiple Sclerosis (pwMS) under different disease modifying therapies (DMTs) and neutralization of the Omicron and Wuhan variants of SARS-COV-2.MethodsIgG anti- SARS-COV-2 spike titer were measured in a cohort of 101 pwMS under fingolimod, dimethyl fumarate, cladribine and antiCD20, as well as 28 healthy controls (HC) were measured 6 weeks after vaccination with 2nd dose (Sputnik V or AZD1222) and 3nd dose (homologous or heterologous schedule). Neutralizing capacity was against Omicron (BA.1) and Wuhan (D614G) variants and pseudotyped particles and Cellular response were analyzed.ResultsMultivariate regression analysis showed anti-cd20 (β= -,349, 95% CI: -3655.6 - -369.01, p=0.017) and fingolimod (β=-,399, 95% CI: -3363.8 - -250.9, p=0.023) treatments as an independent factor associated with low antibody response (r2 adjusted=0.157). After the 2nd dose we found a correlation between total and neutralizing titers against D614G (rho=0.6; p<0.001; slope 0.8, 95%CI:0.4-1.3), with no differences between DMTs. Neutralization capacity was lower for BA.1 (slope 0.3, 95%CI:0.1-0.4). After the 3rd dose, neutralization of BA.1 improved (slope: 0.9 95%CI:0.6-1.2), without differences between DMTs. A fraction of pwMS generated anti-Spike CD4+ and CD8+ T cell response. In contrast, pwMS under antiCD20 generated CD8+TNF+IL2+ response without differences with HC, even in the absence of humoral response. The 3rd dose significantly increased the neutralization against the Omicron, as observed in the immunocompetent population.DiscussionFindings regarding humoral and cellular response are consistent with previous reports.

Background: Knowledge of the safety and efficacy of disease-modifying therapies (DMTs) in older patients with Multiple Sclerosis (pwMS) is limited due to their exclusion from clinical trials. Our purpose is to evaluate the choice of DMTs in pwMS older than 50 years old in a real-world setting. Methods: Cross-sectional study of pwMS from the Argentine MS and NMOSD Registry. We included patients under 35 and above 50 years old prescribed DMTs. Disease activity was categorized as highly active (HA) or not highly active (NHA), and DMTs were classified as low efficacy therapies (LET) or high efficacy therapies (HET). Results: 1460 patients (65% females) were enrolled. The HA group comprised 241 patients, 198 young (82.2%) and 43 older (17.8%). The NHA group included 1219 patients, 893 young (73%) and 326 older (27%). In the NHA group, older patients received LET more frequently than younger patients (66% versus 44%; p < 0.01). In the HA group, older patients received LET in 61% of cases, whereas younger patients received HET in 71% (p = 0.01). Conclusion: The study shows the preference of LET in older patients regardless of disease activity. However it does not demonstrate a difference in disability in older patients based on low vs high efficacy DMTs used, probably due to the design of the study. Further longitudinal studies are warranted to address this issue.

Background Disability progression is a key milestone in the disease evolution of people with multiple sclerosis (PwMS). Prediction models of the probability of disability progression have not yet reached the level of trust needed to be adopted in the clinic. A common benchmark to assess model development in multiple sclerosis is also currently lacking. Methods Data of adult PwMS with a follow-up of at least three years from 146 MS centers, spread over 40 countries and collected by the MSBase consortium was used. With basic inclusion criteria for quality requirements, it represents a total of 15, 240 PwMS. External validation was performed and repeated five times to assess the significance of the results. Transparent Reporting for Individual Prognosis Or Diagnosis (TRIPOD) guidelines were followed. Confirmed disability progression after two years was predicted, with a confirmation window of six months. Only routinely collected variables were used such as the expanded disability status scale, treatment, relapse information, and MS course. To learn the probability of disability progression, state-of-the-art machine learning models were investigated. The discrimination performance of the models is evaluated with the area under the receiver operator curve (ROC-AUC) and under the precision recall curve (AUC-PR), and their calibration via the Brier score and the expected calibration error. All our preprocessing and model code are available at https://gitlab.com/edebrouwer/ms_benchmark, making this task an ideal benchmark for predicting disability progression in MS. Findings Machine learning models achieved a ROC-AUC of 0⋅71 ± 0⋅01, an AUC-PR of 0⋅26 ± 0⋅02, a Brier score of 0⋅1 ± 0⋅01 and an expected calibration error of 0⋅07 ± 0⋅04. The history of disability progression was identified as being more predictive for future disability progression than the treatment or relapses history. Conclusions Good discrimination and calibration performance on an external validation set is achieved, using only routinely collected variables. This suggests machine-learning models can reliably inform clinicians about the future occurrence of progression and are mature for a clinical impact study.

We aimed to assess the treatment strategies utilized in patients with neuromyelitis optica spectrum disorder (NMOSD) experiencing relapses, including their frequency, types, and response after 6 months based on the Expanded Disability Status Scale (EDSS) score. Methods: We conducted a retrospective study involving NMOSD patients from the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177). Treatment response at 6 months was categorized as "good" if the EDSS score decreased by >1 point after a nadir EDSS score <= 3, or by >= 2 points after a nadir EDSS score > 3, "poor" if the EDSS score decrease was slighter, and as "absent" if the EDSS score remained unchanged or worsened. Results: We included 120 NMOSD patients (seropositive N = 75), who experienced 250 NMOSD-related relapses and received 248 treatments. At 6 months, complete recovery was achieved in 70/98 (71.4%) and 15/19 (79%) patients, respectively. Predictors of a "good" response in our regression model were a younger age at disease onset (OR:3.54, CI95% 2.45-5.01, p < 0.0001) and a short delay from onset of relapse to treatment initiation (OR:1.56, CI95% 1.22-2.13, p = 0.004). Conclusions: Approximately two-thirds of patients experienced complete recovery, and younger age and a short delay to start treatment were independent predictors of a "good" response.

BackgroundIt remains unclear whether routine cerebrospinal fluid (CSF) parameters can serve as predictors of multiple sclerosis (MS) disease course.MethodsThis large-scale cohort study included persons with MS with CSF data documented in the MSBase registry. CSF parameters to predict time to reach confirmed Expanded Disability Status Scale (EDSS) scores 4, 6 and 7 and annualised relapse rate in the first 2 years after diagnosis (ARR2) were assessed using (cox) regression analysis.ResultsIn total, 11 245 participants were included of which 93.7% (n=10 533) were persons with relapsing-remitting MS (RRMS). In RRMS, the presence of CSF oligoclonal bands (OCBs) was associated with shorter time to disability milestones EDSS 4 (adjusted HR=1.272 (95% CI, 1.089 to 1.485), p=0.002), EDSS 6 (HR=1.314 (95% CI, 1.062 to 1.626), p=0.012) and EDSS 7 (HR=1.686 (95% CI, 1.111 to 2.558), p=0.014). On the other hand, the presence of CSF pleocytosis (≥5 cells/µL) increased time to moderate disability (EDSS 4) in RRMS (HR=0.774 (95% CI, 0.632 to 0.948), p=0.013). None of the CSF variables were associated with time to disability milestones in persons with primary progressive MS (PPMS). The presence of CSF pleocytosis increased ARR2 in RRMS (adjusted R2=0.036, p=0.015).ConclusionsIn RRMS, the presence of CSF OCBs predicts shorter time to disability milestones, whereas CSF pleocytosis could be protective. This could however not be found in PPMS. CSF pleocytosis is associated with short-term inflammatory disease activity in RRMS. CSF analysis provides prognostic information which could aid in clinical and therapeutic decision-making.

Background: Most Multiple Sclerosis (MS) clinical trials fail to assess the long-term effects of disease-modifying therapies (DMT) or disability. Methods: COLuMbus was a single-visit, cross-sectional study in Argentina in adult patients with >= 10 years of MS since first diagnosis. The primary endpoint was to determine patient disability using the Expanded Disability Status Scale (EDSS). The secondary endpoints were to evaluate the distribution of diagnoses between relapsingremitting MS (RRMS) and secondary progressive MS (SPMS), patient demographics, disease history, and the risk of disability progression. The relationship between baseline characteristics and the current disability state and the risk of disability progression was assessed. Results: Out of the 210 patients included, 76.7 % had a diagnosis of RRMS and 23.3 % had been diagnosed with SPMS, with a mean disease duration of 17.9 years and 20.5 years, respectively. The mean delay in the initial MS diagnosis was 2.6 years for the RRMS subgroup and 2.8 years for the SPMS subgroups. At the time of cut-off (28May2020), 90.1 % (RRMS) and 75.5 % (SPMS) of patients were receiving a DMT, with a mean of 1.5 and 2.0 prior DMTs, respectively. The median EDSS scores were 2.5 (RRMS) and 6.5 (SPMS). In the RRMS and SPMS subgroups, 23 % and 95.9 % of patients were at high risk of disability, respectively; the time since first diagnosis showed a significant correlation with the degree of disability. Conclusions: This is the first local real-world study in patients with long-term MS that highlights the importance of recognizing early disease progression to treat the disease on time and delay disability.

We aimed to assess the frequency, duration, and severity of area postrema syndrome (APS) during follow-up in neuromyelitis optica spectrum disorder (NMOSD) patients, as well as its association with inflammatory activity and prognostic factors of APS severity in a real-world setting. We conducted a retrospective study on a cohort of Latin American (LATAM) NMOSD patients who had experienced APS during their follow-up. Patients from Mexico, Peru, Brazil, Colombia, Panama, Chile and Argentina patients who met 2015 NMOSD criteria were included. We evaluated data on symptom type (nausea, vomiting and/or hiccups), frequency, duration, severity (measured by APS severity scale), association with other NMOSD core relapses, and acute treatments (symptomatic and immunotherapy or plasmapheresis). Logistic regression was conducted to evaluate factors associated with APS severity (vs. mild-moderate). Out of 631 NMOSD patients, 116 (18.3

OBJECTIVE:The aim was to evaluate patient profiles, effectiveness and safety of cladribine (CLAD) in patients with relapsing-remitting multiple sclerosis in Argentina.METHODS:This was a substudy included in RelevarEM (MS and neuromyelitis optica registry in Argentina, NCT03375177). Patients with MS who received CLAD tablets and were followed up for at least 24 months were included. Clinical evaluations every 3 months collect information about: a) clinical relapses; b) progression of physical disability, evaluated through Expanded Disability Status Scale, and c) new lesions found in the magnetic resonance imaging. Lymphopenia was evaluated during the follow-up and defined as grade 1: absolute lymphocyte count (ALC) 800-999/μL; grade 2: ALC 500-799/μL; grade 3: ALC 200-499/μL and grade 4: ALC <200/μL.RESULTS:A total of 240 patients were included from 19 centers from Argentina. The mean annualized relapse rate during the 12-month pre-CLAD initiation was 1.19 ± 0.56 versus 0.22 ± 0.18 at month 12 and 0.19 ± 0.15 at month 24 (P < 0.001). A total of 142 (59.2%) fulfilled the criteria of disease activity during the 12 months before treatment initiation, whereas 27 (11.3%) fulfilled it at month 12 and 38 (15.8%) at month 24, P < 0.001. Regarding no evidence of disease activity (NEDA), 202 (84.2%) patients achieved NEDA status at month 12 and 185 (77%) at month 24. The most frequent incidence density of lymphopenia for course 2 observed was also for grade 1, 6.1 (95% confidence interval [CI] = 5.5-7.1). The overall incidence density of lymphopenia grade 4 was 0.1 (95% CI = 0.06-0.19).CONCLUSION:This information will help when choosing the best treatment option for Argentinean patients.