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.

Evaluation of the use of high-efficacy treatments (HETs) in patients with relapsing-remitting multiple sclerosis in Argentina.

BACKGROUND: Disease-modifying therapies (DMTs) in multiple sclerosis (MS) can be classified according to the efficacy in which they prevent inflammatory activity. To date, there are limited data regarding the use of high-efficacy treatments (HETs) in Latin America (LATAM). We aimed to analyze the use of HETs in Argentina, focusing on the clinical and sociodemographic characteristics of the patients who use these treatments and the changes in the trend of use over the years. METHODS: A retrospective cohort study was done using the Argentina MS patient registry, RelevarEM. Patients diagnosed with relapsing-remitting MS (RRMS) according to validated diagnostic criteria and under treatment with natalizumab, alemtuzumab, cladribine, rituximab or ocrelizumab were included. RESULTS: Out of 2450 RRMS patients under a DMT, 462 (19%) were on HETs. One third of those patients (35%) received HETs as the first treatment. The most frequent reason for switching to HETs was treatment failure to previous DMT (77%). The time from MS diagnosis to the first HET in treatment-naive patients was less than one year (IQR: 0-1 year) and in treatment-experienced patients it was 5 years (IQR: 3-9 years). Between 2015 and 2017 (P1), 729 patients included in RelevarEM started a new treatment, of which 85 (11.65%) were HETs. Between 2018 and 2020 (P2), 961 patients included in RelevarEM started a new treatment, of which 284 (29.55%) were HETs. When comparing P2 with P1, a significant increase in the use of HETs was observed (p < 0.01). The most frequently used HETs were alemtuzumab (50.59%) in P1, and cladribine (45.20%) in P2. CONCLUSION: The demographic and clinical characteristics of patients under HET in Argentina were identified. Based on a real-world setting, we found a significant trend towards and a rapid increase in the use of HETs in clinical practice in patients with RRMS.

Encefalitis por inhibidores del punto de control inmunitario / Encephalitis associated to immune checkpoint inhibitors

Resumen Los inhibidores del punto de control inmunitario han demostrado mejorar el pronóstico de múltiples enfer medades oncológicas. Recientemente se han reportado eventos adversos relacionados a la inmunoterapia. La to xicidad neurológica es poco frecuente. Se presenta el caso de un paciente con encefalitis relacionada con inhibido res del punto de control inmunitario.

Abstract Immune checkpoint inhibitors have been shown to improve the prognosis of multiple oncological diseases. Recently, adverse events related to immunotherapy have been reported. Neurologic toxicity is infrequent. We pre sent the case of a patient with encephalitis associated to immune checkpoint inhibitors.

Latin American consensus recommendations on the risk of infections in people with multiple sclerosis treated with disease modifying drugs.

INTRODUCTION: The emergence of several therapeutic options in multiple sclerosis (MS), which significantly modify the immune system functioning, has led to the need for the consideration of additional factors, such as risk of infections, in the decision-making process. The aim of these consensus recommendations was to discuss and perform a practical guide to Latin American neurologists on the risk of infections at diagnosis, follow-up and prior to initiation of DMDs. METHODS: A panel of Latin American neurologists, experts in demyelinating diseases and dedicated to management and care of MS patients, gathered during 2021 and 2022 to make consensus recommendations on the risk of infections in PwMS treated with DMDs in Latin America. The RAND/UCLA methodology was developed to synthesize the scientific evidence and expert opinions on health care topics and was used for reaching a formal agreement. RESULTS: Recommendations were established based on relevant published evidence and expert opinion, focusing on: 1- baseline infection disease and vaccination status; 2- opportunistic infections; 3- progressive multifocal leukoencephalopathy; 4- genitourinary system infections; 5- respiratory tract infections; 6- digestive system infections, 7-others local infections and 8- COVID-19. CONCLUSION: The recommendations of this consensus seek to optimize the care, management and treatment of PwMS in Latin America. The standardized evidence-based care of pwMS infections will allow better outcomes.

[Encephalitis associated to immune checkpoint inhibitors]. / Encefalitis por inhibidores del punto de control inmunitario.

Immune checkpoint inhibitors have been shown to improve the prognosis of multiple oncological diseases. Recently, adverse events related to immunotherapy have been reported. Neurologic toxicity is infrequent. We present the case of a patient with encephalitis associated to immune checkpoint inhibitors.

Los inhibidores del punto de control inmunitario han demostrado mejorar el pronóstico de múltiples enfermedades oncológicas. Recientemente se han reportado eventos adversos relacionados a la inmunoterapia. La toxicidad neurológica es poco frecuente. Se presenta el caso de un paciente con encefalitis relacionada con inhibidores del punto de control inmunitario.

Relevance and Impact of Social Support on Quality of Life for Persons With Multiple Sclerosis.

BACKGROUND: Social support is crucial for persons with multiple sclerosis (MS). We sought to analyze differences in perceived social support in persons with MS vs controls; to study associations between perceived social support, clinical measures, and health-related quality of life (HRQOL) variables in persons with MS; and to establish a predictive value of perceived social support for HRQOL. METHODS: We studied 151 persons with MS (mean ± SD: age, 42.01 ± 9.97 years; educational level, 14.05 ± 3.26 years) and 89 controls (mean ± SD: age, 41.46 ± 12.25 years; educational level, 14.60 ± 2.44 years) using the Medical Outcomes Study Social Support Survey (MOS-SSS), Expanded Disability Status Scale, Fatigue Severity Scale, Beck Depression Inventory, and Multiple Sclerosis International Quality of Life (MusiQoL) questionnaire. Parametric and nonparametric statistical methods were used accordingly; P < .05. RESULTS: Persons with MS exhibited lower scores on the MOS-SSS's overall support index (t238 = -1.98, P = .04) and on each functional subscale (t238 = -2.56 to -2.19, P < .05). No significant differences were found on the social support structural component (P > .05). Significant associations were observed between social support and depression and fatigue (r = -0.20 to -0.29, P < .05) and with MusiQoL dimensions (r = -0.18 to 0.48, P < .05). Multiple regression analysis showed all 4 tested models contributed to HRQOL-explained variance (41%-47%). The emotional/informational support model explained the most HRQOL variability (47%). CONCLUSIONS: Persons with MS perceived reduced social support, presenting lower functional scores than controls. Perceived social support proved to be a predictor of HRQOL. These findings should be considered during therapeutic treatment.

Achieving no evidence of disease activity-3 in highly active multiple sclerosis patients treated with cladribine and monoclonal antibodies.

Background: We aimed to determine the proportion of highly active multiple sclerosis patients under high-efficacy therapies (HETs) achieve no evidence of disease activity-3 (NEDA-3) at 1 and 2 years, and to identify factors associated with failing to meet no evidence of disease activity 3 at 2 years. Methods: This retrospective cohort study based on Argentina Multiple Sclerosis patient registry (RelevarEM), includes highly active multiple sclerosis patients who received HETs. Results: In total, 254 (78.51%) achieved NEDA-3 at year 1 and 220 (68.12%) achieved NEDA-3 at year 2. Patients who achieved NEDA-3 at 2 years had a shorter duration of multiple sclerosis (p < 0.01) and a shorter time between first treatment and current treatment (p = 0.01). Early high-efficacy strategy patients reached NEDA-3 more frequently (p < 0.01). Being a naïve patient (odds ratio: 3.78, 95% confidence interval 1.50-9.86, p < 0.01) was an independent predictor to reach NEDA-3 at 2 years. No association was found between type of HETs and NEDA-3 at 2 years when adjusted for potential confounders (odds ratio: 1.73; 95% confidence interval 0.51-6.06, p 0.57). Conclusion: We found a high proportion of patients who achieved NEDA-3 at 1 and 2 years. Early high-efficacy strategy patients had a higher probability of achieving NEDA-3 at 2 years.

Barriers to access and unmet needs to neuromyelitis optica spectrum disorders care in an Argentinean cohort.

INTRODUCTION: Neuromyelitis optica spectrum disorder (NMOSD) is a rare but severe neuroimmunological condition associated with a significant financial burden. NMOSD is also associated with increased health care utilization, including neurology outpatient visits, magnetic resonance imaging (MRI) use, long-term medication, among others. We aimed to evaluate real-world patient experiences in access to care and NMOSD burden in an Argentinean cohort. METHODS: This cross-sectional study used a self-administered survey and was conducted in Argentina (2022). Patients with NMOSD were divided into three groups: private health insurance (PHI), social health insurance (SHI), and public health insurance (PHI, Ministry of Public Health). Differences in access and health care barriers were assessed. RESULTS: One hundred patients with NMOSD (74 women) with a mean age at diagnosis of 38.7 years were included. Their EDSS was 2.8 and they were followed for 5.2 years. Of them, 51%, 11%, and 13% were employed (full-time: 57.5%), currently unemployed and retired by NMOSD, respectively. 55% of them visited between 2-3 specialists before NMOSD diagnosis. Aquaporin-4-antibody and/or myelin oligodendrocyte glycoprotein-antibody testing was requested in 91% (health insurance covered this partially in 15.3% and 32.9% of the time the test was entirely paid by patient/family). Patients with NMOSD receiving private medical care reported greater access to MRI, outpatient visits, and fewer issues to obtain NMOSD medications compared to those treated at public institutions. A longer mean time to MRI and neurology visit was found in the PHI group when compared with the other two subgroups. Regression analysis showed that private insurance (OR=3.84, p=0.01) was the only independent factor associated with appropriate access to NMOSD medications in Argentina. CONCLUSION: These findings suggest that barriers to access and utilization of NMOSD care services in Argentina are common. NMOSD patients experienced problems to receive NMOSD medication properly, especially those from the public sector.

Disease activity after discontinuation of disease-modifying therapies in patients with multiple sclerosis in Argentina: data from the nationwide registry RelevarEM.

INTRODUCTION: The discontinuation of disease-modifying therapies (DMTs) in multiple sclerosis (MS) is commonly seen in real-world settings due to several factors. AREA COVER: The aim of this study is to describe the frequency of disease activity after discontinuation of DMTs in MS patients included in the Argentinean MS and NMOSD registry. DISCUSION: Patients with relapsing remitting MS (RRMS) and active secondary progressive MS (SPMS) were included based on the following criteria: they discontinued treatment for more than 6 months, they had been treated with a DMT for ≥2 years, and they had at least 6 months of follow-up in the registry after discontinuation. Demographic and clinical data were collected. Disease activity during follow-up was defined as the presence of a clinical relapse or a new magnetic resonance (MRI) lesion (either new lesions on T2-weighted sequence and/or contrast enhancement). Bivariate analysis was applied to identify clinical and demographic factors related to disease activity. CONCLUSION: We included 377 patients (75.5% RRMS, 22.5% SPMS) who had discontinued DMTs. The mean (SD) follow-up after discontinuation was 15.7 (7.9) months. After discontinuation, the presence of relapse was detected in 18.8% and 3.5% in RRMS and SPMS, respectively; and new MRI activity in 22% and 3.5%, respectively. We found that higher risk of relapse and MRI activity was associated with younger age (p < 0.001), shorter disease duration (p < 0.001), and RRMS phenotype (p = 0.006). Males showed higher MRI activity (p 0.011). This study provides real-world data that can guide physicians when considering discontinuation of DMTs.

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.

Frequency of NMOSD misdiagnosis in a cohort from Latin America: Impact and evaluation of different contributors.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) misdiagnosis (i.e. the incorrect diagnosis of patients who truly have NMOSD) remains an issue in clinical practice. We determined the frequency and factors associated with NMOSD misdiagnosis in patients evaluated in a cohort from Latin America. METHODS: We retrospectively reviewed the medical records of patients with NMOSD, according to the 2015 diagnostic criteria, from referral clinics in six Latin American countries (Argentina, Chile, Paraguay, Colombia, Ecuador, and Venezuela). Diagnoses prior to NMOSD and ultimate diagnoses, demographic, clinical and paraclinical data, and treatment schemes were evaluated. RESULTS: A total of 469 patients presented with an established diagnosis of NMOSD (73.2% seropositive) and after evaluation, we determined that 56 (12%) patients had been initially misdiagnosed with a disease other than NMOSD. The most frequent alternative diagnoses were multiple sclerosis (MS; 66.1%), clinically isolated syndrome (17.9%), and cerebrovascular disease (3.6%). NMOSD misdiagnosis was determined by MS/NMOSD specialists in 33.9% of cases. An atypical MS syndrome was found in 86% of misdiagnosed patients, 50% had NMOSD red flags in brain and/or spinal magnetic resonance imaging (MRI), and 71.5% were prescribed disease-modifying drugs. CONCLUSIONS: NMOSD misdiagnosis is relatively frequent in Latin America (12%). Misapplication and misinterpretation of clinical and neuroradiological findings are relevant factors associated with misdiagnosis.

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.

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.

Evaluation of adherence to treatment in patients with multiple sclerosis from Latin America.

INTRODUCTION AND AIM: Several factors have been associated with poor adherence to disease-modifying drugs (DMD). The aim of this study is to evaluate the adherence to DMD in people with multiple sclerosis (PwMS) in Argentina and Ecuador. METHODS: A cross-sectional study was performed. The study was carried out between June 2020 and October 2020, and 303 PwMS treated with DMD were included. Patients undergoing immune reconstitution treatments were excluded. Two definitions of DMD adherence were previously determined. Adherence to MS treatments was assessed using the multiple sclerosis treatment adherence questionnaire (MS-TAQ). The logistic regression model was used to evaluate factors related to adherence, and p < 0.05 was considered significant. RESULT: The mean age at study entry for patients was 40.7 ± 11.2 years, 207 (68.3%) were female, and the mean EDSS score was 2.2 ± 1.9. The overall adherence in our sample was 78.1% (79.7% in Argentina and 76% Ecuador, p = 0.23). Patients using infusion therapies significantly more often belonged to the adherent group (p = 0.042). Sharing decision-making (OR = 3.4, 95% CI: 1.7-6.9, p = 0.01), lower EDSS (OR = 0.8, 95% IC: 0.6-0.9, p = 0.004), and lower treatment duration (OR = 0.8, 95% IC: 0.6-0.9, p = 0.001) were independent predictors of adherence in our multivariate model. CONCLUSION: We found a prevalence of non-adherence similar to that previously reported. Furthermore, new factors associated with lower adherence were identified.

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.

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.

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.