Clinical impact of gender and age at onset on disease trajectory in primary progressive multiple sclerosis patients.

BACKGROUND AND OBJECTIVES: Primary-progressive multiple sclerosis (PPMS) is characterized by gradual neurological deterioration without relapses. This study aimed to investigate the clinical impact of gender and age at disease onset on disease progression and disability accumulation in patients with this disease phenotype. METHODS: Secondary data from the RelevarEM registry, a longitudinal database in Argentina, were analyzed. The cohort comprised patients with PPMS who met inclusion criteria. Statistical analysis with multilevel Bayesian robust regression modeling was conducted to assess the associations between gender, age at onset, and Expanded Disability Status Scale (EDSS) score trajectories. RESULTS: We identified 125 patients with a confirmed diagnosis of PPMS encompassing a total of 464 observations. We found no significant differences in EDSS scores after 10 years of disease progression between genders (-0.08; credible interval (CI): -0.60, 0.42). A 20-year difference in age at onset did not show significant differences in EDSS score after 10 years of disease progression (0.281; CI: -0.251, 0.814). Finally, we also did not find any clinically relevant difference between gender EDSS score with a difference of 20 years in age at onset (-0.021; CI: -0.371, 0.319). CONCLUSION: Biological plausibility of gender and age effects does not correlate with clinical impact measured by EDSS score.

Incidence of SARS-CoV-2 infection in patients with multiple sclerosis who received SARS-CoV-2 vaccines and are under treatment with high-efficacy therapies in Argentina.

We aimed to evaluate the incidence of SARS-CoV-2 breakthrough infection of SARS-CoV-2 vaccines in people with MS (PwMS) on high-efficacy disease-modifying therapies (HET) included in the national MS registry in Argentina (RelevarEM). METHODS: Non-interventional, retrospective cohort study that collected information directly from RelevarEM. Adult PwMS who had been treated for at least 6 months with a HET (ocrelizumab, natalizumab, alemtuzumab, cladribine) who had received at least two doses of SARS-CoV-2 vaccines available in Argentina were included. Full course of vaccination was considered after the second dose of the corresponding vaccines. Cumulative incidence of SARS-CoV-2 infection was reported for the whole cohort by Kaplan-Meier survival curves (which is expressed in percentage) as well as incidence density (which is expressed per 10.000 patients/day with 95% CI). RESULTS: Two hundred twenty-eight PwMS were included. Most frequent first and second dose received was AstraZeneca vaccine, followed by Sputnik vaccine. Most frequent HETs used in included patients were cladribine in 79 (34.8%). We found an incidence density of breakthrough COVID-19 infection of 3.5 × 10.000 patients/day (95% CI 2.3-6.7) after vaccination in Argentina. We described the incidence rate after vaccination for every HET used, it being significantly higher for ocrelizumab compared with other HETs (p = 0.005). Only five patients presented a relapse during the follow-up period with no differences regarding the pre-vaccination period. CONCLUSIONS: We found an incidence density of breakthrough COVID-19 infection of 3.5 × 10.000 patients/day (95% CI 2.3-6.7) after vaccination in Argentina.

Argentinean consensus recommendations for the use of telemedicine in clinical practice in adult people with multiple sclerosis.

BACKGROUND: The use of telemedicine has quickly increased during of the COVID-19 pandemic. Given that unmet needs and barriers to multiple sclerosis (MS) care have been reported, telemedicine has become an interesting option to the care of these patients. The objective of these consensus recommendations was to elaborate a guideline for the management of people with MS using telemedicine in order to contribute to an effective and high-quality healthcare. METHODS: A panel of Argentinean neurologist's experts in neuroimmunological diseases and dedicated to the diagnosis, management,and care of MS patients gathered virtually during 2021 and 2022 to conduct a consensus recommendation on the use of telemedicine in clinical practice in adult people with MS. To reach consensus, the methodology of "formal consensus RAND/UCLA Appropriateness method" was used. RESULTS: Recommendations were established based on relevant published evidence and expert opinion focusing on definitions, general characteristics and ethical standards, diagnosis of MS, follow-up (evaluation of disability and relapses of MS), identification and treatment of relapses, and finally disease-modifying treatments using telemedicine. CONCLUSION: The recommendations of this consensus would provide a useful guide for the proper use of telemedicine for the assessment, follow-up, management, and treatment of people with MS. We suggest the use of these guidelines to all the Argentine neurologists committed to the care of people with MS.

Disability outcomes in NMOSD and MOGAD patients: data from a nationwide registry in Argentina.

The objective was to evaluate time to reach an EDSS of 4, 6, and 7 in NMOSD and MOGAD patients included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03,375,177). METHODS: NMOSD patients diagnosed according to 2015 criteria and with MOGAD were identified. Patients with at least 3 years of follow-up and periodic clinical evaluations with EDSS outcomes were included. AQP4-antibody and MOG-antibody status was recorded, and patients were stratified as seropositive and seronegative for AQP4-antibody. EDSS of 4, 6, and 7 were defined as dependent variables. Log rank test was used to identify differences between groups. RESULTS: Registry data was provided for a total of 137 patients. Of these, seventy-five presented AQP4-ab-positive NMOSD, 45 AQP4-ab-negative NMOSD, and 11 MOGAD. AQP4-ab status was determined by cell-based assay (CBA) in 72% of NMOSD patients. MOG-ab status was tested by CBA in all cases. Mean time to EDSS of 4 was 53.6 ± 24.5 vs. 63.1 ± 32.2 vs. 44.7 ± 32 months in seropositive, seronegative NMOSD, and MOGAD, respectively (p = 0.76). Mean time to EDSS of 6 was 79.2 ± 44.3 vs. 75.7 ± 48.6 vs. 54.7 ± 50 months in seropositive, seronegative NMOSD, and MOGAD (p = 0.23), while mean time to EDSS of 7 was 86.8 ± 54 vs. 80.4 ± 51 vs. 58.5 ± 47 months in seropositive, seronegative NMOSD, and MOGAD (p = 0.39). CONCLUSION: No differences were observed between NMOSD (seropositive and seronegative) and MOGAD in survival curves.

Clinical and demographic characteristics of primary progressive multiple sclerosis in Argentina: Argentinean registry cohort study (RelevarEM).

BACKGROUND: Primary progressive multiple sclerosis (PPMS) is an infrequent clinical form of multiple sclerosis (MS). Scarce information is available about PPMS in Latin America. The aim of this work is to describe the clinical and demographic characteristics of PPMS patients in Argentina. MATERIAL AND METHODS: RelevarEM is a longitudinal, strictly observational registry in Argentina. Clinical and epidemiological data from PPMS patients were described. RESULTS: There were 144 cases of PPMS. They represented 7% of MS patients. The mean age was 44.1 years. The female:male ratio was 1.08. The mean Expanded Disability Status Scale (EDSS) score was 5.5 and the mean disease evolution time was 10.6 years. Oligoclonal bands were found in 72.9%. At the time of diagnosis, magnetic resonance imaging showed spinal cord lesions in 82.6% and contrast-enhancing brain lesions in 18.1% of patients. Almost one third of patients were treated with a disease-modifying drug, and ocrelizumab was the most frequently used (55.8%). CONCLUSIONS: PPMS is an infrequent subtype of MS and its recognition is of the highest importance as it has its own evolution, treatment, and prognosis. The importance of our research resides in providing local data and contributing to a better understanding of PPMS and its treatment in Latin America.

Multiple sclerosis and neuromyelitis optica spectrum disorders in Argentina: comparing baseline data from the Argentinean MS Registry (RelevarEM).

The objective of this study was to describe and compare the baseline epidemiological data of multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients included in RelevarEM (Clinical Trials registry number NCT03375177). METHODS: RelevarEM is a longitudinal, strictly observational MS and NMOSD registry in Argentina. Epidemiological and comorbidity data from MS and NMOSD patients were described and compared. For comorbidities, the Charlson comorbidity index (CCI) was used to calculate the burden at entry. CCI was stratified in 0 and ≥ 1 and described for the entire cohort. RESULTS: A total of 1588 and 75 MS and NMOSD patients (respectively) were included. For MS patients, the mean age was 42 ± 7 years, female sex 65.3%, mean EDSS 2, and mean disease duration 8 ± 6 years. In NMOSD, the mean age was 40 ± 7 years, female sex 78.7%, mean disease duration 5 ± 3.5 years, and mean EDSS 2.5. The most frequent MS phenotype was RRMS in 82.4%. In MS, the CCI was 0 in 85.8.2% while ≥ 1 was in 14.2% of patients. Regarding phenotype stratification, CCI ≥ 1 was 3.9% in CIS, 13.5% in RRMS, 28.7% in SPMS, and 17.4% in PPMS (p < 0.001 between groups). In NMOSD, the CCI was 0 in 64% while ≥ 1 was in 36%. The MS/NMOSD ratio found was 21/1. CONCLUSIONS: This is the first analysis of the longitudinal Argentinean registry of MS and NMOSD describing and comparing conditions that contributes to provide reliable real-world data in the country.

[Emotional valence effect on prospective memory in relapsing remitting Multiple Sclerosis]. / Efecto de valencia emocional sobre la memoria prospectiva en pacientes con esclerosis múltiple recaídas y remisiones.

INTRODUCTION: prospective memory is the ability to remember to perform actions in the future. Currently there is no consensus about the relationship between prospective memory and emotional processing. OBJECTIVE: The aim of this work is to determine the influence of the emotional valence of prospective memory signals on prospective recall in patients diagnosed with multiple sclerosis. METHOD: 37 patients with multiple sclerosis and 32 healthy volunteers were recruited. An experimental test was made where the concurrent task consisted in a 2-back working memory activity and the prospective component consisted of remembering to press a key on the computer when an image of positive, negative or neutral emotional content appears on the screen. RESULTS: An intra-group comparison was made between the memory of emotional and neutral stimuli, and it was obtained that the differences are significant in both groups in favor of the recall of stimuli with neutral valence (Z = -3.39, p = .001 for the control group and Z = -2.63, p = .008 for multiple sclerosis). DISCUSSION: The results indicate that emotionally neutral target stimuli benefits prospective memory in normal people and in multiple sclerosis patients. The limitations of the implemented method are discussed.

Real-World Effectiveness and Safety of Cladribine in Multiple Sclerosis: Longitudinal Data From the Nationwide Registry in Argentina.

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.

Selection of disease modifying therapies in multiple sclerosis based on patient's age and disease activity: Data from a nationwide registry.

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.

Effects of early treatment with glatiramer acetate in patients with clinically isolated syndrome.

BACKGROUND: The placebo-controlled phase of the PreCISe study showed that glatiramer acetate delayed onset of clinically definite multiple sclerosis (CDMS) in patients with clinically isolated syndrome and brain lesions on MRI. OBJECTIVE: To compare the effects of early versus delayed glatiramer acetate treatment in the open-label phase of PreCISe. METHODS: Patients with a clinically isolated syndrome suggestive of MS with unifocal manifestation and ≥2 T2-weighted brain lesions were randomized to receive glatiramer acetate 20 mg/d (early-treatment, n=198) or placebo (delayed-treatment, n=211) for 36 months or until conversion to CDMS, followed by open-label glatiramer acetate treatment for two years. RESULTS: Early glatiramer acetate treatment reduced CDMS conversion risk by 41% (hazard ratio 0.59, 95% confidence interval 0.44-0.80; p=0.0005) versus delayed-treatment, and was associated with a 972-day delay (185%) in conversion to CDMS, less brain atrophy (-28%, p=0.0209), fewer new T2 lesions/year (-42%, <0.0001) and lower T2 lesion volume (-22%, p=0.0005) versus delayed treatment. Adverse events were consistent with the established safety profile of glatiramer acetate. CONCLUSIONS: Effects of early glatiramer acetate treatment on the rate of conversion to CDMS and on MRI measures of disease activity and lesion burden support initiating glatiramer acetate treatment soon after the first clinical symptoms suggestive of MS and continuing treatment to sustain benefits.

[Severity of COVID-19 in patients with multiple sclerosis in Argentina]. / Infección grave por COVID-19 en pacientes con esclerosis múltiple en la Argentina.

INTRODUCTION: There is limited local information on the risk of severe COVID-19 infection in patients with multiple sclerosis (MS) who are receiving disease-modifying treatments (DMT). The aim of the study was to assess the impact of COVID-19 disease (severity and lethality) in MS patients receiving DMT. METHODS: The study was performed on a prospective cohort with EM. We included 111 patients with MS and a confirmed diagnosis of COVID-19 treated with DMT and followed up until the resolution of COVID-19. RESULTS: A total of six patients (5.4%; 95% CI: 2-11.4%) developed severe COVID-19 defined as requiring hospitalization in intensive care unit or death and three died (crude case fatality rate of 2.7%; 95% CI: 1.1-4.3%). The age-adjusted case fatality rate was 1.5% (95% CI: 0.6-2.4%). The factor that was independently associated with severe COVID-19 was age (OR 1.1; CI 1.0-1.3; p < 0.05) with a trend in the Expanded Disability Status Scale (EDSS) = 6 (OR 6.2; CI 0.6-56.4; p = 0.10). CONCLUSION: The lethality due to COVID-19 in MS patients is low, and severity was significantly associated with age and showed a trend with EDSS = 6.

Introducción: Existe poca información local sobre el riesgo de infección grave por COVID-19 en pacientes con esclerosis múltiple (EM) que reciben tratamiento modificador de la enfermedad (DMT). El objetivo del estudio fue evaluar el impacto de la enfermedad por COVID-19 (gravedad y letalidad) en pacientes con EM que reciben DMT. Métodos: El estudio se realizó sobre una cohorte prospectiva de pacientes con EM. Se incluyeron 111 con EM y diagnóstico confirmado de COVID-19 tratados con DMT, seguidos hasta la resolución del COVID-19. Resultados: Un total de seis (5.4%; IC 95%: 2-11.4%) desarrollaron COVID-19 grave definido como requerimiento de internación en terapia intensiva o muerte, y tres fallecieron (tasa de letalidad cruda del 2.7%; IC 95%: 1.1-4.3%). La tasa de letalidad ajustada por edad fue del 1.5% (IC 95%: 0.6-2.4%). El factor que se asoció independientemente con COVID-19 grave fue la edad (OR 1.1; IC 1.0-1.3; p < 0.05) con una tendencia en la Escala del Estado de Incapacidad Ampliada (EDSS) = 6(OR 6.2; IC 0.6-56.4; p = 0.10). Conclusión: La letalidad por COVID-19 en pacientes con EM es baja y la gravedad se asoció significativamente con la edad y mostró una tendencia con EDSS = 6.

Practical issues concerning the use of Magnetic Resonance Imaging in Multiple Sclerosis in Latin America: Discussion from 16 centres on behalf of the Foro Latam EM Study Group.

MAGNIMS-CMSC-NAIMS consensus recommendations on the use of MRI in patients with multiple sclerosis have been recently published, and they have been fundamental for improving patient care. Implementation of these and previous MAGNIMS recommendations have not been established in many countries. Addressing the local limitations behind these difficulties is needed. A panel of 14 MS neurologists from 16 different reference centres from Chile, Argentina, Mexico, Colombia, Ecuador, Panamá, Perú and Brazil met to discuss the current situation regarding the use of MRI in MS including a) Access and availability, b) Standardized acquisition protocols and reports, and c) Multicentric research potential.

Decision making process in multiple sclerosis: An Argentine pilot study.

BACKGROUND: There is scarce information regarding the decision-making process (DMP) in people with MS (PwMS) from Latin America. OBJECTIVE: To evaluate the DMP in Argentinean PwMS and to assess its relationship with patient preferences, and clinical-demographic characteristics. METHODS: PwMS from the patient organization Esclerosis Múltiple Argentina (n = 1275) were invited to participate in a self-administered web-based survey. Participants were asked to provide clinical-demographic information and to complete a questionnaire on their perceptions about the information provided by their physician, the Control Preference Scale, and the Satisfaction with the Decisions and Care Questionnaire, and were inquired on their preferred sources of information about MS. RESULTS: The survey was completed by 379 PwMS. Most were females (67%); mean age: 40.3 (SD = 11.1) years; mean disease duration: 7.9 (SD = 7.2) years. Patients' decisional control preferred role was active in 47%, shared in 27%, and passive in 26%. A moderate concordance (weighted kappa 0.55) was observed between patients' preferences and self-reported DMP. Seventy-two percent participated in the DMP according to their preferences (concordance rates: active 66%, shared 87%, passive 51%). Most (83%) declared receiving information from their neurologists, matching their preferences (94%). CONCLUSIONS: Argentinian PwMS have distinctive preferences regarding information management and decision making.

Evaluation of the times of disability progression and related factors in patients with primary progressive multiple sclerosis from Argentina.

Background PPMS (primary progressive multiple sclerosis) patients represent less than 10% of MS patients in Argentina, men and women were similarly affected and most of them had a severe functional impairment. More rapid progression has been reported in males, but this is not the case in all datasets. The main objective of our study was to determine the time to EDSS (Expanded disability Status Scale) 4, 6 and 7 in PPMS patients. We also compared the times to reach these EDSS in men and women and aimed to identify factors associated with the disability progression. Method This cohort of patients with diagnosis of PPMS (n = 253) was selected from follow-up recorded in the RelevarEM registry database. Result The median times to EDSS 4, 6 and 7 were 24 (IQR 12-48), 72 (IQR 36-96) and 96 (IQR 60-120) months, respectively. Comparison of the survival curves to EDSS 4, 6 and 7 according to gender did not show significant differences (p = 0.33, p = 0.55 and p = 0.59). There is no evidence of an association between the clinical adjustment variables (sex, age >40 years at diagnosis, EDSS > 3 at onset and multifocal MS symptoms at disease onset) and the time of arrival at the EDSS 4, 6 and 7. Conclusion Severe disability was observed six years after the onset of symptoms. No association was found between the studied factors and the time to arrival to severe disability.

Rebound activity after fingolimod cessation: A case - control study.

BACKGROUND: There has been an increase in the number of reports of multiple sclerosis (MS) rebound activity (RA), which is usually defined as a severe disease reactivation after natalizumab or fingolimod withdrawal that exceeds pre-treatment baseline inflammatory activity. The frequency and risk factors that could predict RA remain unknown. Fingolimod is currently the most frequently prescribed disease modifying therapy for MS in Argentina, so that there is a need to determine possible predictors of RA. OBJECTIVES: To identify risk factors for developing RA after fingolimod cessation; to describe RA characteristics, management and evolution. METHODS: The study was a multicenter, retrospective, case-control study of patients with MS who had discontinued fingolimod and were followed up to nine months after discontinuation. Demographic, clinical and paraclinical data was extracted, including age, gender, MS phenotype, reason for discontinuation, number of relapses during the year prior to suspension, time treated with fingolimod, EDSS before, during and after rebound, MRI findings. RESULTS: 26 cases of RA were matched 1:1 with patients without RA. The median time elapsed to RA was 50 days. 68% showed worsening of the EDSS in the evaluation at 3 months of RA. When compared with the control group, no difference was found in terms of age, gender, phenotype, EDSS at the moment of suspension, reason for discontinuation, number of relapses in the previous year, and time on therapy. CONCLUSION: In this case-controlled study, no risk factors could be identified to predict RA after fingolimod cessation. Further controlled, prospective, better powered studies are needed to confirm these findings.

Accumulative risk of clinical event in high-risk radiologically isolated syndrome in Argentina: data from the nationwide registry RelevarEM.

INTRODUCTION: We aimed to analyze the accumulative risk of MRI and OB factors for evolution from RIS to MS in subjects included in the Argentinean MS registry (NCT03375177). METHODS: RIS subjects were identified according to RIS diagnosis criteria. Subjects were longitudinally followed with clinical and MRI at intervals of 6 months. Time from RIS identification to the first clinical event was estimated using Kaplan-Meier. Multivariable Cox regression models were created to assess the independent predictive value of demographic characteristics, as well as clinical, OB and MRI data on time to the first clinical event. The single and increased risk factor of evolution of RIS was quantified. RESULTS: A total of 88 RIS subjects, mean follow-up time 42 ± 4 months were included. 39 (44.3%) and 23 (26.1%) had a new MRI lesion or a clinical event, respectively, during the follow-up. OB (HR 5.9, 95% CI 1.29-10.1, p = 0.004), infratentorial lesions (HR 3.7, 95% CI 1.09-7.5) and spinal cord lesions (HR 5.3, 95% CI 1.4-8.2, p = 0.01) at RIS identification were independent predictors associated with a subsequent clinical event. The accumulative risk showed that when two of the three factors (OB, infratentorial or spinal cord lesions) were present the HR was 10.4, 95% CI 4.4-22, p < 0.001, and when three factors were present, it was HR 15.6, 95% CI 5.7-28, p < 0.001 for a relapse. CONCLUSION: The presence of three factors significantly increased the risk of clinical event; high-risk subjects should probably be managed by a different approach than those used for individuals without high-risk factors.

Clinical and demographic characteristics of male MS patients included in the national registry-RelevarEM. Does sex or phenotype make the difference in the association with poor prognosis?

BACKGROUND: In multiple sclerosis demographics there is a well-known female prevalence and male patients have been less specifically evaluated in clinical studies, though some clinical differences have been reported between sexes. OBJECTIVE: The objective of this study was to assess clinical and demographic differences between male and female patients included in the national Argentine MS Registry-RelevarEM. MATERIAL AND METHODS: This study was observational, retrospective, and was based on the data of 3099 MS patients included as of 04 April 2021. The statistical analysis plan included bivariate analyses with the crude data and also after adjustment for the MS phenotype, further categorized as progressive-onset MS or relapsing-onset MS. In the adjusted analysis, the Mantel-Haenszel odds ratio was compared to the crude odds ratio, to account for the phenotype as a confounder. RESULTS: The data from 1,074 (34.7%) men and 2,025 (65.3%) women with MS diagnosis were analysed. Males presented primary progressive disease two times more often than women (11% and 5%, respectively). In the crude analyses by sex, the presence of exclusively infratentorial lesions in the magnetic resonance imaging studies was more frequent in males than in females, but after adjustment by MS onset phenotype, such difference was only present in males with relapsing-onset MS (p = 0.00006). Similarly, worse Expanded Disability Status Scale scores were confirmed only in men with relapsing-onset disease after phenotype adjustment (p = 0.02). CONCLUSION: We did not find any statistically significant clinical or demographic difference between sexes when the progressive MS phenotype was specifically considered. However, the differences we found between the clinical phenotypes are in line with the literature and highlight the importance of stratifying the analyses by sex and phenotype when designing MS studies.

Incidence of COVID-19 after vaccination in people with multiple sclerosis in Argentina: Data from the nationwide registry RelevarEM.

The objective of the study was to evaluate the incidence of COVID-19 after complete vaccination in people with multiple sclerosis (PwMS) included in the Argentinean MS and NMOSD registry (RelevarEM, NCT03375177). METHODS: cohort study conducted between May 2021 and December 2021. The primary outcome was the appearance of infection during the follow-up time (at least three months after complete vaccination (second dose)). Data was collected through the contact between the treating physician and the patient. Specific information was requested (date, symptoms, need for hospitalization, ventilatory assistance, treatment, and evolution). The contact was made every 30 days during the period of 3 months after the full dose vaccination. A positive COVID-19 case was defined according to the definition established by the Ministry of Health in Argentina. Cumulative incidence was reported by Kaplan Meier survival curves as well as incidence density. RESULTS: A total of 576 PwMS were included, mean age 45.2 ± 13 years, 432 (75%) RRMS, 403 (70%) were female. The mean and median time of follow-up after the second dose was 91 ± 17 and 94 ± 21 days respectively. Most frequent first and second dose received was Astra-Zeneca vaccine, followed by Sputnik V vaccine. During follow-up a total of twenty COVID-19 cases were observed for a total exposure time of 39,557 days. The overall cumulative incidence for the observed period was 3.4% (SE 0.4%) with an overall incidence density of 5 × 10.000 patients/day (95%CI 0.7-12). We observed more cases in woman than men with an incidence density of 6 × 10.000 patients/day (95%CI 0.9-9) vs. 3 × 10.000 patients/day (95%CI 0.2-6) respectively, but not significantly different (IRR 1.7 95% CI 0.56-7.37 p = 0.15). CONCLUSION: we found an incidence density of breakthrough COVID-19 infection of 5 × 10.000 patients/day (95%CI 0.7-12) after vaccination in Argentina.