Raúl Carrea Institute for Neurological Research, Fleni
Neurology

Author Of 14 Presentations

Diagnostic Criteria and Differential Diagnosis Poster Presentation

P0268 - Time interval between disease onset and MS diagnosis during the last decades in Latin America (ID 1201)

Speakers
Presentation Number
P0268
Presentation Topic
Diagnostic Criteria and Differential Diagnosis

Abstract

Background

Previous studies have shown a significant shortening of time from multiple sclerosis (MS) onset (first relapse) to diagnosis in parallel with the adoption of new diagnostic criteria. However, the observation was not evaluated in Latin America.

Objectives

The objective of the study was to study the interval from first symptom of MS to the date of diagnosis in relation to the introduction of upgraded MS diagnostic criteria in a Latin American population.

Methods

Cross-sectional study based on a self-reported survey. Patients with MS completed a regional survey in 12 Latin American countries. To be included, date of disease onset (first relapse) and date of diagnosis (confirmed disease) should be completed. Survival probabilities were evaluated for 5 diagnosis epoch groups according to the diagnostic criteria advised at the time: group 1- 1983-2000 Poser; group 2- 2001-2004 McDonald's first version; group 3- 2005-2009 revisions of 2005; group 4- 2010-2016 revisions of 2010; and group 5 -2017-2019 revisions of 2017.

Results

1434 patients were included. 1108 (75%) females, mean age at study entry 39 ± 11 years. The mean time since disease onset to diagnosis in group 1 was 21 ± 8 months; in group 2, 19 ± 7 months; in group 3, 16 ± 10 months; in group 4, 9.6 ± 8.5 months and in group 5, 8.2 ± 10 months. Significant differences were observed between groups 1, 2, 3 vs. 4 and 5 (p<0.001) while no differences were observed between group 4 and 5 (p=0.08).

Conclusions

This study showed a significant shortening of time from MS onset to diagnosis in parallel with the adoption of new diagnostic criteria in Latin America in recent decades.

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Disease Modifying Therapies – Mechanism of Action Poster Presentation

P0270 - 2-Chlorodeoxyadenosine (Cladribine) preferentially inhibits the biological activity of microglia cells (ID 1011)

Speakers
Presentation Number
P0270
Presentation Topic
Disease Modifying Therapies – Mechanism of Action

Abstract

Background

Background and goals: 2-chlorodeoxyadenosine (CdA, Cladribine) is a compound used in the treatment of MS, which crosses the BBB and is activated by intracellular phosphorylation in specific cell types. We previously demonstrated that CdA inhibits microglial cell proliferation, induces apoptosis and suppress IL-1, IL-6 and TNF-α secretion; effects not observed in the case of astrocytes.

Objectives

To expand previous findings to better explain differences observed between these two cell populations in response to cladribine.

Methods

Primary cultures of microglial cells and astrocytes were prepared from neonatal C57BL/6 mice following the McCarthy and de Vellis protocol. After harvesting, cells were treated with different concentrations of CdA (20 to 200 µM), for periods lasting between 6 and 72 hours. Caspase 3 expression was evaluated by immunocytochemistry. CdA effect on mitochondrial function of microglial cells was measured using an extracellular flux analyzer (Seahorse). Expression of DCK and 5-NT enzymes, as well as of the ABCG2 receptor were measured using RT-PCR. DCK enzyme activity was assessed by ELISA.

Results

Caspase-3 expression was measured in microglial cells, 6-12 hours after exposure to CdA, preceding induction of apoptosis. CdA showed no effect on mitochondrial bioenergetics when cells were treated with a wide range of CdA concentrations (20-200 µM). To investigate differences in response to CdA between microglia and astrocytes, we measured DCK and 5-NT expression as well as expression of the CdA receptor ABCG2 in both cell populations. DCK expression was significantly higher in microglial cells than in astrocytes. By contrast, 5-NT expression was higher in astrocytes than in microglial cells; whereas expression of the ABCG2 receptor was significantly higher in microglia compared to astrocytes. Finally, incubation of microglial cells in the presence of CdA induced significant DCK enzyme activity, which increased further after LPS activation.

Conclusions

Data presented complements previous findings on biological effects induced by CdA on microglial cells, leading to a better understanding of differences in microglia and astrocyte cell responses. We observed that microglia showed: 1) greater expression of the CdA receptor ABCG2, increasing intracellular pro-drug penetration; and 2) higher expression of the phosphorylating enzyme DCK, which transforms CdA into an active drug.

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Disease Modifying Therapies – Mechanism of Action Poster Presentation

P0408 - Therapeutic Plasma Exchange in MS relapses: long term outcome (ID 1415)

Speakers
Presentation Number
P0408
Presentation Topic
Disease Modifying Therapies – Mechanism of Action

Abstract

Background

High-dose short-term intravenous methylprednisolone (IVMP) is the standard treatment for Multiple Sclerosis (MS) relapses. However, 25% of patients do not respond and remain with significant disability. In these patients, therapeutic plasma exchange (TPE) has proven effective, although evidence of long-term efficacy after use of this procedure is lacking.

Objectives

The aims of this study were to: 1) compare outcomes of patients treated with or without TPE at 12, 18 and 24 months, and 2) evaluate features associated with better response to TPE.

Methods

We performed a retrospective cohort study of all relapse remitting MS patients (RRMSp) treated with IVMP and TPE between January 2011 and January 2018 and compared them to a second group of RRMSp, matched for age, sex, disease duration and disability level at time of relapse, treated only with IVMPS. Number of relapses were recorded. Good response to treatment was defined as at least 50% reduction in EDSS score. Results were reported as median and interquartile range for numerical variables, and as percentage of the total number of patients, for categorical variables. P values below 0.05 were considered significant.

Results

Twenty-four patients (66% female, age: 39± 11 years) treated with TPE, and 43 patients treated with IVMP alone (70% female, age: 39± 6 years) were included. TPE-treated patients had experienced more relapses in the 2-years prior to the study (3±2 vs 2±1, p=0,03). Time from symptom onset to treatment with IVMP or duration of IVMP treatment was similar in both groups (5 ± 9 days vs 7± 11 days, p=0.1). After the relapse, TPE-treated patients were escalated to a high efficacy disease modifying therapy more frequently during follow up than the comparator group (25% vs 16%, p=0,02).

Although initial EDSS scores were similar in both groups, no differences were found in EDSS or Kurtzke functional systems scores at 12, 18 and 24-months follow-up (TPE 1 (0-2) vs IVMP 1 (0-2)).

65% of RRMSp treated with TPE had a good response to treatment. No significant association was found between positive response and initial relapse severity, distribution or number of gadolinium-enhancing lesions, or time to TPE.

Conclusions

No differences in functional outcomes were found in MS relapses treated with or without TPE after 24 months follow up; nor were any predictors of favorable response to treatment with TPE in this preliminary analysis.

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Epidemiology Poster Presentation

P0427 - Absence of latitudinal gradient in oligoclonal bands prevalence in Argentina (ID 858)

Abstract

Background

Similarly, to what occurs with MS prevalence, it has been previously described that oligoclonal bands (OCB) prevalence follows a latitudinal gradient being more frequent farther away from the equator. Argentina has the particularity of being longitudinally extensive (21°46’S to 66°13’S). Previous epidemiological studies from Argentina have not found an MS prevalence latitudinal gradient.

Objectives

The aim of the present study is to describe the prevalence of OCB in CSF in patients with MS, CIS and RIS included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177) and to investigate if the prevalence follows a latitudinal gradient.

Methods

RelevarEM is a longitudinal, observational MS and NMOSD registry in Argentina. For each province, an average latitude was calculated using extreme N and S latitudes obtained from Google Maps. Regarding OCB, pattern II or III where considered as positive. The frequency of OCB was calculated for each diagnostic category (MS, CIS, RIS) and for each province. Statistical analysis was carried out using SPSS v22. Multivariate logistical regression analysis was performed considering OCB as a dichotomic dependent variable and latitude as an ordinal independent variable, adjusted by clinically relevant variables. Also, the percentage of patients OCB positive for each province was calculated and linear correlation was tested.

Results

We included 2866 patients from different locations in Argentina (92.4% MS, 5.8% CIS and 1.8% RIS). The mean age at diagnosis (SD) was 32.7 (11.2), 35.2 (10.7) and 40.7 (11.2) for MS, CIS and RIS patients, respectively. Lumbar puncture was performed in 54.6%, 63.9%, and 43.4% of MS, CIS and RIS patients, respectively. OCB where positive in 75.4%, 55.7% and 60.9% of MS, CIS and RIS patients, respectively. No association was found between OCB positivity and latitude, adjusted by gender, age at diagnosis and diagnostic category. No linear correlation was found between the percentage of OCB positive patients and latitude.

Conclusions

Similarly, to what has been described regarding MS prevalence, OCB positivity does not seem to follow a latitudinal gradient in Argentina. Also, OCB positivity in our study is lower that described in previous reports from other world regions.

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Comorbidities Poster Presentation

P0483 - Prevalence of cancer in multiple sclerosis patients in Argentina: cross sectional study from RelevarEM (ID 1043)

Abstract

Background

Multiple Sclerosis (MS) is an autoimmune demyelinating and neurodegenerative disease of the central nervous system of multifactorial origin. Studies about the prevalence of cancer in MS population are scarce and results are conflicting. Previous studies described a higher prevalence as well as an increased risk of cancer in MS patients while there are others that found no differences regarding general population.

Objectives

The aim of our study was to estimate the prevalence of cancer in a large sample of multiple sclerosis patients in Argentina.

Methods

the eligible study population and cohort selection included all patients with definite MS included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177) at 31 December 2019. History of current or past cancer diagnosis, was collected. Prevalence rates and 95% CI were calculated.

Results

We analyzed 2647 MS patients. 14 malignancies were identified. Overall prevalence of cancer was 0.53% (CI95% 0.02-0.08%). 78.6% were female, 85.8% relapsing remitting MS, median (IQR) disease duration: 10.5 (6-13) years; median (IQR) age at diagnosis: 42.5 (37-49); median (IQR) age at study date: 52.5, median (IQR); current EDSS: 2 (1.5-4.5); 42% patients were untreated and 58% under DMT (beta interferon 1a: 14.3%, 1b: 7.1%, glatiramer acetate: 7.1% and fingolimod: 28.6%). Most frequent malignancy was breast cancer (28.6%).

Conclusions

The prevalence of cancer in MS population identified in Argentina was 0.53% (CI 95% 0.02-0.08), being females more affected than males and breast cancer the most frequent one.

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Epidemiology Poster Presentation

P0493 - Severe infections in patients with multiple sclerosis: a nationwide registry study in Argentina (ID 929)

Abstract

Background

Data on the rates of infections among patients with multiple sclerosis (MS) are sparse and even more from Latin American countries.

Objectives

The objective of this study was to quantify the incidence of severe infections (SI) in patients with MS included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177).

Methods

RelevarEM is a longitudinal, strictly observational MS and NMOSD registry in Argentina. From May 2018 to March 2020, the centers and principal investigators were contacted and incorporated into the Registry. SI were defined as those that required intravenous treatment or that led to hospitalization or death. Patients contributed person-years of follow-up for the study period. Incidence rates and 95% CI were calculated.

Results

A total of 2158 patients with MS were included, mean age 42 (IIQ 34-52), 65,5% (1576) were female, 82,3% were RRMS. During the period (May 2018-March 2020), 28 SI were reported (IR 1.16, 95%CI 0.77-1.68). In patients with SI, the mean age was 54 (min 43- max 63, p<0.01) years, 11 (39%) were secondary progressive MS (p<0.01), the mean EDSS was 6.5 (range 5-8)(p<0.01), mean disease duration 12 years (p<0.01). 42% of patients were free of MS treatment while 17% were on injectables, 25% on orals and 10% on monoclonal antibodies (p=0.24). The most common sites of severe infection were the lower respiratory tract (39%)

Conclusions

IR of severe infection during the study period was 1.16 (95%CI 0.77-1.68). Most frequent SI were in SPMS and older patients while no relation was observed regarding MS treatment.

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Imaging Poster Presentation

P0649 - The Central Vein Sign discriminates multiple sclerosis from its radiological mimics in the clinical setting (ID 1503)

Presentation Number
P0649
Presentation Topic
Imaging

Abstract

Background

The “central vein sign” (CVS) in white matter lesions (WMLs) is a current radiological biomarker of multiple sclerosis (MS). Using magnetic susceptibility-based sequences, the CVS was observed in 80-100% of lesions at 7.0 tesla Magnetic Resonance Imaging (MRI) in the research setting. Recently, similar detection rate was reported at 3.0 Tesla (3T) MRI in the clinical setting using susceptibility-weighted angiography (SWAN)-venule sequence. Some data suggest that using 3D T2*EPI/ FLAIR*, the CVS may be useful to differentiate MS from other neurological diseases with focal WMLs.

Objectives

The objective of our study was to determine if the CVS detected in SWAN-venule at 3T MRI discriminates MS from its radiological mimics.

Methods

Subjects were scanned on a 3T MRI system (Discovery MR750, GE, Milwaukee, USA) using a 32-channel head coil. We performed post-contrast 3D-FLAIR and SWAN-venule sequences [FOV = 22 cm x 16 cm; number of slices= 126; voxel resolution, 0.4 mm x 0.4 mm x 0.8 mm; TR = 47 msec; TE = 28 msec; flip angle = 8° ; ETL = 9; AT = 7.38 min]. MRIs with focal supratentorial WMLs visible in FLAIR, larger than 3 mm and smaller than 15 mm, were included. The CVS, defined as a thin hypointense line or a hypointense small dot centering a WML, was recorded blinded to the diagnosis on SWAN-venule by one junior neuroradiologist and two trained MS raters.

Results

Twenty people with MS and 24 subjects with non-MS WMLs: 9 migraine, 6 Neuromyelitis Optica spectrum disease (NMOs), 5 Susac Syndrome (SS), and 4 with other vascular diseases (2 primary angiitis of the central nervous system, 1 small vessels disease, and 1 Lupus), were included. A total of 380 WMLs were detected in the MS group, and 427 WMLs in the non-MS group (215 migraine, 52 NMOs, 83 SS, and 77 in other vascular diseases). The CVS was detected in 86% of MS WMLs compared to 23% of WMLs of other diseases (25% of migraine, 21% of NMOs, 22% of other vascular diseases).

Conclusions

The use of SWAN-venule sequence for the identification of CVS on 3T MRI helps differentiate MS WMLs from other WMLs that mimic MS.

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Microbiome Poster Presentation

P0671 - Exploring the gut microbiome in multiple sclerosis via the international MS Microbiome Study (iMSMS) (ID 1532)

Abstract

Background

The gut microbiota is emerging as a critical regulator of immune responses and appears to play an important role in MS. The International Multiple Sclerosis Microbiome study (iMSMS) is a global collaboration aimed at elucidating the role of commensal gut bacteria in MS by acquiring and analyzing samples from 2000 patients and 2000 household healthy controls.

Objectives

The iMSMS focuses on identifying the microbes, genes and pathways that are involved in MS pathogenesis and on investigating how the microbiome changes response to treatment.

Methods

A total of 576 case and household healthy control pairs were recruited from 7 centers located in the US (West and East coasts), Europe and South America. Stool samples were collected and evaluated by both 16S and shallow whole metagenome shotgun sequencing. Univariate and multivariate linear regression analyses were conducted to understand patterns of variation on gut microbiome.

Results

This is the largest MS microbiome study reported to date. Our results showed a statistically significant difference of beta diversity between MS and healthy controls for the first time in MS. Intriguingly, multiple species of Akkermansia, including the known mucin-degrading bacterium Akkermansia muciniphila, were significantly enriched in untreated MS patients after adjusting for confounding factors, but the difference was not detected in treated MS group versus control. Ruminococcus torques and Eisenbergiella tayi were also among the top significantly enriched bacteria in MS. Inversely, a main butyrate producer, Faecalibacterium prausnitzii, was significantly decreased in the untreated MS group. Functional pathways of L-tryptophan biosynthesis and L-threonine biosynthesis were slightly increased in untreated MS patients, while 5-aminoimidazole ribonucleotide biosynthesis I was increased in the treated group.

Conclusions

Our large household-controlled study allowed us to identify modest but statistically robust MS-associated changes in bacterial composition and functions. It provides the foundation for all future studies of the gut microbiota in MS. The strain-level genomic variation and microbiome-derived molecules need to be further explored for understanding microbial adaptation and pathogenicity.

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Neuromyelitis Optica and Anti-MOG Disease Poster Presentation

P0720 - Incidence of relapses in NMOSD patients under immunosupressive therapies in Argentina: observational study from RelevarEM. (ID 1684)

Abstract

Background

Several retrospective studies have demonstrated the clinical benefits of immunosuppressive therapies (IST) such as azathioprine (AZA), mycophenolate mofetil (MMF) and rituximab (RTX) for reducing relapse rates in neuromyelitis optica spectrum disorders (NMOSD) patients. However, there is considerable uncertainty regarding the relative benefits and harms associated with each of these IST in real world clinical practice and current data describing the strategies are limited

Objectives

The objective of this study was to describe the incidence of relapses in patients with NMOSD under IST included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177).

Methods

We conducted a retrospective cohort study from RelevarEM. RelevarEM is a longitudinal, strictly observational MS and NMOSD registry in Argentina. From May 2018 to June 2020, the centers and principal investigators were contacted, and patients were incorporated into the Registry. NMOSD patients were defined based on the 2015 International Consensus Diagnostic Criteria for NMOSD. Relapses during the study period, demographics and radiological (e.g. new/enlarging and/or enhancing-contrast MRI lesions) data were collected. Only patients under IST were included in the analysis. Patients contributed person-years of follow-up for the study period. Incidence rates and 95% CI were calculated. Thus, global and associated with each IST incidence density rate of relapses was estimated.

Results

We included a total of 132 (77% women) NMOSD patients with a median age at diagnosis of 36 years (27-47) and a disease duration of 6 years (4-10). Aquaporin-4 antibody was positive in 54.8%. At the time of entering the registry, 39.4% were treated with RTX, 33.3% with AZA, 3.6% MMF. The global incidence density rate of relapse was 0.032/person-year (CI95% 0,021-0,048), for RTX 0.051 (CI95% 0,024-0,1) and for AZA 0,031 (CI95% 0,016-0,06). There were no relapses in the group of MMF during this period of time.

Conclusions

This study showed a low incidence density rate of relapses in NMOSD patients under IST during this study period. Further studies will help expand our initial findings, hopefully leading to improve treatment options for NMOSD patients.

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Neuromyelitis Optica and Anti-MOG Disease Poster Presentation

P0762 - What percentage of AQP4-Ab-negative NMOSD patients are MOG-Ab positive? A study from the Argentinean multiple sclerosis registry (RelevarEM) (ID 1033)

Abstract

Background

Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) have been described in aquaporin-4-antibodies(AQP4-Ab)-negative neuromyelitis optica spectrum disorders (NMOSD) patients.

Objectives

We aimed to investigate the percentage of AQP4-Ab-negative NMOSD patients who are positive for MOG-Ab included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177).

Methods

RelevarEM is a longitudinal, strictly observational multiple sclerosis (MS) and NMOSD registry in Argentina. Epidemiological, serological test and neuroimaging (MRI) data from NMOSD were described.

Results

A total of 165 patients (79 AQP4-Ab positive, 67 AQP4-Ab negative and 19 unknown) were included. Of these, 155 patients fulfilled the 2015 NMOSD diagnostic criteria. Of 67 AQP4-Ab-negative patients, 36 were tested for MOG-Ab and 10 of them (31.8%) tested positive. Presence of relapses during the previous 6 months (40% vs. 12.9%), shorter disease duration (3.9 vs. 7.5 years), lower disability (2.3 vs. 3.4) and treatment duration (1.5 vs. 3.4 years) and both optic neuritis (90% vs. 44.5%) and optic nerve lesion on MRI (80% vs. 25.1%) were significantly associated with MOG-Ab-positive compared with NMOSD respectively

Conclusions

This is the first study of the longitudinal Argentinean registry of MS and NMOSD describing and comparing diseases that contributes to provide reliable real-world data in the country. We observed that 31.8% (10/36) of the AQP4-ab-negative patients tested for MOG-Ab were positive for this antibody, in line with results from other world regions.

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Observational Studies Poster Presentation

P0836 - Aggressive multiple sclerosis in Argentina: data from the nationwide registry RelevarEM (ID 1632)

Abstract

Background

Aggressive MS (AMS) describes a form of the disease with a rapid progressive course leading to significant disability in multiple neurologic systems or even death in a relatively short time after onset. Despite there being no consensus on the exact definition of AMS, several studies performed during the last years have tried to better identify and understand the frequency and distribution as well as the progression and treatment response in order to determine more accurately which patients with AMS would most benefit from higher-efficacy, higher-risk treatments

Objectives

The objectives of the present study were to describe the frequency of aggressive multiple sclerosis (AMS) as well as to compare clinical and radiological characteristics in AMS and non-AMS patients included in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177).

Methods

The eligible study population and cohort selection included adult-onset patients (≥18 years) with definite MS. AMS were defined as those reaching confirmed EDSS ≥6 within 5 years from symptom onset. Confirmation was achieved when a subsequent EDSS ≥6 was recorded at least six months later but within 5 years of the first clinical presentation. AMS and non-AMS were compared using the χ2 test for categorical and the Mann-Whitney for continuous variables at MS onset and multivariable analysis was performed using forward stepwise logistic regression with baseline characteristics at disease onset.

Results

A total of 2158 patients with MS were included: 74 AMS and 2084 non-AMS. The prevalence of AMS in our cohort was 3.4% (95%CI 2.7-4.2). AMS were more likely to be male (p=0.003), older at MS onset (p<0.001), have primary progressive MS (PPMS) phenotype (p=0.03), multifocal presentation (p<0.001), and spinal cord as well as infratentorial lesions at MRI during disease onset (p=0.004 and p=0.002, respectively).

Conclusions

3.4% of our patient population could be considered AMS. Men, patients older at symptom onset, multifocal presentation, PPMS phenotype, and spinal cord as well as brainstem lesion on MRI at clinical presentation all had higher odds of having AMS.

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Observational Studies Poster Presentation

P0930 - Usage trend of oral drugs for multiple sclerosis in Argentina (ID 1183)

Abstract

Background

Over the past decade, numerous disease modifying drugs (DMDs) for relapsing multiple sclerosis (RMS) have been approved in Argentina. It is believed that the use of oral DMDs (oDMDs) i.e. fingolimod, teriflunomide and dimetil fumarate has increased in recent years, although the real-life data in our country is limited.

Objectives

Our aim was to describe the tendency of the use of oDMDs (as first treatment option or after switch) regarding its approval in Argentina.

Methods

A retrospective study was conducted in a cohort of MS patients follow-up in five Argentinian MS centers incorporated in the Argentinean MS and NMOSD registry (RelevarEM, NCT 03375177). Patients who started their treatment since 2012 were included. Regarding to the availability of different oDMDs in Argentina, we define three period (P1-3): P1: 2012 – 2014; P2: 2015 - 2017 and P3: 2018 - 2020. An analysis was performed comparing between these three periods to assess the tendency of oDMDs use over time. Three scenarios were defined: initial treatment, first switch and second switch. For the switch scenarios, only P1 and P2 were analyzed considering that the patients belonging P3 have a short evolution time and a scarce patient’s number required treatment changes.

Results

Out of 202 patients, 58% were female, mean age 32.4 ±11.0 years, mean disease evolution 8.0 ±5.5 years, 46 % started with oDMDs and 64% was the first choice after a switch. Injectable therapies were the most frequently withdrawn in relation to oDMDs and monoclonal antibodies (p<0.01). The main cause of switching treatment was treatment failture (39%). We found an increase in the use of oDMDs as initial treatment over time (P1: 17.7%, P2: 63.9% and P3: 65.0%; p <0.01). We found a tendency in increasing use of oDMDs after a first switch (P1: 59.6%, P2: 73.1%) or second switch (P1: 59.6%, P2: 73.1%). Multivariate analysis showed that disease evolution (OR=1.06, p=0.04), and year of starting treatment (OR=0.66, p<0.01) were independently associated with choice of oDMDs.

Conclusions

We have identified an increasing tendency in the use of oDMDs as initial treatment of RMS regarding its approval in Argentina.

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Pathogenesis – Immunology Poster Presentation

P0985 - Obesity and Multiple Sclerosis risk. The role of Leptin (ID 1008)

Speakers
Presentation Number
P0985
Presentation Topic
Pathogenesis – Immunology

Abstract

Background

Obesity in childhood and in adolescence increases the risk of MS by inducing a chronic low-grade inflammatory state, characterized by altered secretion of adipokines, of which leptin is the best characterized.

Objectives

The main goal of this study was to investigate the effects of leptin on different T cell populations, in order to gain more insight into the link between leptin and obesity.

Methods

Three hundred and nine RRMS patients and 322 matched controls were invited to participate in a cross-sectional survey, to confirm whether excess weight/obesity in adolescence or early adulthood were associated with increased risk of MS.

Serum leptin levels were determined by ELISA. MBP83-102, and MOG63-87 peptide-specific T cells lines were expanded from peripheral blood mononuclear cells. Leptin receptor, p-STAT3, pERK1/2, and p27kip1 expression were assayed using RT-PCR. Apoptosis induction was determined by Annexin V detection. Cytokines were assessed by ELISPOT and ELISA, and regulatory T cells (Treg cells) detected by flow cytometry.

Results

Logistic regression analysis, with smoking as covariate, showed excess weight at age 15 and obesity at age 20 increased the risk of developing MS (OR=2.16, p=0.01 and OR=3.89, p=0.009). Leptin levels correlated with BMI(r=0.88, p<0.0001) in both groups. Addition of Leptin to cultures increased proliferation of autoreactive T cells, reduced apoptosis induction, and promoted pro-inflammatory cytokines secretion (p values < 0.001). Obese patients produced higher numbers of pro- inflammatory cytokines-secreting cells compared to overweight/normal/underweight subjects (p<0.001).

Inverse correlation was found between leptin levels and circulating CD4+CD25+ Treg cells (r=-0.97, p<0.0001). Leptin also inhibited Treg cell proliferation, inducing hypo-responsiveness. Effects of leptin on autoreactive T cells were mediated by increased STAT3 and ERK1/2 phosphorylation and down modulation of the cell cycle inhibitor P27kip1. By contrast, leptin effects on Treg cells were mediated by decreased phosphorylation of ERK1/2 and upregulation of p27kip1.

Conclusions

Leptin has a dual effect on T cell modulation. On one hand it promotes proliferation of autoreactive T cells, secretion of pro-inflammatory cytokines, and exerts an anti-apoptotic action. On the other, leptin inhibits Treg cell proliferation, inducing hypo-responsiveness, mediated by the opposite effects of STAT3, ERK1/2 phosphorylation, and p27kip1 expression.

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Invited Presentations Invited Abstracts

TC16.02 - Presentation 02 (ID 636)

Speakers
Authors
Presentation Number
TC16.02
Presentation Topic
Invited Presentations

Abstract

Abstract

Multiple Sclerosis (MS) is a chronic inflammatory disease of the Central Nervous System (CNS) that affects young people leading to demyelination and neurodegeneration. Although its etiology is not clear it is known that autoimmunity plays a major role in disease pathogenesis influenced by environmental and genetic factors. The disease is clearly more common among women and its incidence in females has been rising causing an increase in sex bias Clinic and epidemiological data shows clear differences among sexes: women experience more frequent relapses, have more inflammatory lesions on MRI and earlier onset of MS compared to men. Male sex, on the other hand, is associated with faster progression and worse outcome with more cerebellar involvement, worse cognition, more gray matter atrophy and more T1 lesions. There are also important changes related to female reproductive cycle with a 3-fold increase in MS prevalence after menarche, a decrease of approximately 70% in relapse rates in the third trimester of pregnancy and an increase in relapse rate in 3-6 months after delivery to nearly three times higher than pre-pregnancy levels. During menopause recent evidence suggest worsening of MS symptoms and probably an increase in disease progression.

Hormonal factors and/or sex chromosomes are thus assumed to be involved in regulating the course of the disease and due to the presence of receptors on immune cells, sex hormones (estrogens, progesterone, prolactin and testosterone) can influence different aspects of immune system function and potentially affect the risk, activity and progression of MS. Sex hormones have different effects depending not only on the concentration but also on the type of target cell and the receptor subtype expressed on a given cell type. Thus, understanding how gender impacts MS requires the elucidation of complex interactions among sex hormones, sex chromosomes, immune response genes, and resident cells of the CNS. We will discuss clinical evidence that shows the impact of hormonal factors in MS. Then, we will try to elucidate the complex hormonal and immunological mechanisms potentially underlying these changes, as well as the current knowledge and new insights into the relationship of sex hormones and resident CNS cells in the context of MS. Understanding those molecular mechanisms may help to provide ways to develop novel and safer treatments for both men and women.

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Presenter Of 2 Presentations

Disease Modifying Therapies – Mechanism of Action Poster Presentation

P0270 - 2-Chlorodeoxyadenosine (Cladribine) preferentially inhibits the biological activity of microglia cells (ID 1011)

Speakers
Presentation Number
P0270
Presentation Topic
Disease Modifying Therapies – Mechanism of Action

Abstract

Background

Background and goals: 2-chlorodeoxyadenosine (CdA, Cladribine) is a compound used in the treatment of MS, which crosses the BBB and is activated by intracellular phosphorylation in specific cell types. We previously demonstrated that CdA inhibits microglial cell proliferation, induces apoptosis and suppress IL-1, IL-6 and TNF-α secretion; effects not observed in the case of astrocytes.

Objectives

To expand previous findings to better explain differences observed between these two cell populations in response to cladribine.

Methods

Primary cultures of microglial cells and astrocytes were prepared from neonatal C57BL/6 mice following the McCarthy and de Vellis protocol. After harvesting, cells were treated with different concentrations of CdA (20 to 200 µM), for periods lasting between 6 and 72 hours. Caspase 3 expression was evaluated by immunocytochemistry. CdA effect on mitochondrial function of microglial cells was measured using an extracellular flux analyzer (Seahorse). Expression of DCK and 5-NT enzymes, as well as of the ABCG2 receptor were measured using RT-PCR. DCK enzyme activity was assessed by ELISA.

Results

Caspase-3 expression was measured in microglial cells, 6-12 hours after exposure to CdA, preceding induction of apoptosis. CdA showed no effect on mitochondrial bioenergetics when cells were treated with a wide range of CdA concentrations (20-200 µM). To investigate differences in response to CdA between microglia and astrocytes, we measured DCK and 5-NT expression as well as expression of the CdA receptor ABCG2 in both cell populations. DCK expression was significantly higher in microglial cells than in astrocytes. By contrast, 5-NT expression was higher in astrocytes than in microglial cells; whereas expression of the ABCG2 receptor was significantly higher in microglia compared to astrocytes. Finally, incubation of microglial cells in the presence of CdA induced significant DCK enzyme activity, which increased further after LPS activation.

Conclusions

Data presented complements previous findings on biological effects induced by CdA on microglial cells, leading to a better understanding of differences in microglia and astrocyte cell responses. We observed that microglia showed: 1) greater expression of the CdA receptor ABCG2, increasing intracellular pro-drug penetration; and 2) higher expression of the phosphorylating enzyme DCK, which transforms CdA into an active drug.

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Invited Presentations Invited Abstracts

TC16.02 - Presentation 02 (ID 636)

Speakers
Authors
Presentation Number
TC16.02
Presentation Topic
Invited Presentations

Abstract

Abstract

Multiple Sclerosis (MS) is a chronic inflammatory disease of the Central Nervous System (CNS) that affects young people leading to demyelination and neurodegeneration. Although its etiology is not clear it is known that autoimmunity plays a major role in disease pathogenesis influenced by environmental and genetic factors. The disease is clearly more common among women and its incidence in females has been rising causing an increase in sex bias Clinic and epidemiological data shows clear differences among sexes: women experience more frequent relapses, have more inflammatory lesions on MRI and earlier onset of MS compared to men. Male sex, on the other hand, is associated with faster progression and worse outcome with more cerebellar involvement, worse cognition, more gray matter atrophy and more T1 lesions. There are also important changes related to female reproductive cycle with a 3-fold increase in MS prevalence after menarche, a decrease of approximately 70% in relapse rates in the third trimester of pregnancy and an increase in relapse rate in 3-6 months after delivery to nearly three times higher than pre-pregnancy levels. During menopause recent evidence suggest worsening of MS symptoms and probably an increase in disease progression.

Hormonal factors and/or sex chromosomes are thus assumed to be involved in regulating the course of the disease and due to the presence of receptors on immune cells, sex hormones (estrogens, progesterone, prolactin and testosterone) can influence different aspects of immune system function and potentially affect the risk, activity and progression of MS. Sex hormones have different effects depending not only on the concentration but also on the type of target cell and the receptor subtype expressed on a given cell type. Thus, understanding how gender impacts MS requires the elucidation of complex interactions among sex hormones, sex chromosomes, immune response genes, and resident cells of the CNS. We will discuss clinical evidence that shows the impact of hormonal factors in MS. Then, we will try to elucidate the complex hormonal and immunological mechanisms potentially underlying these changes, as well as the current knowledge and new insights into the relationship of sex hormones and resident CNS cells in the context of MS. Understanding those molecular mechanisms may help to provide ways to develop novel and safer treatments for both men and women.

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Moderator Of 1 Session

Teaching Course Fri, Sep 11, 2020
Session Type
Teaching Course
Date
Fri, Sep 11, 2020

Invited Speaker Of 1 Presentation

Invited Presentations Invited Abstracts

TC16.02 - Presentation 02 (ID 636)

Speakers
Authors
Presentation Number
TC16.02
Presentation Topic
Invited Presentations

Abstract

Abstract

Multiple Sclerosis (MS) is a chronic inflammatory disease of the Central Nervous System (CNS) that affects young people leading to demyelination and neurodegeneration. Although its etiology is not clear it is known that autoimmunity plays a major role in disease pathogenesis influenced by environmental and genetic factors. The disease is clearly more common among women and its incidence in females has been rising causing an increase in sex bias Clinic and epidemiological data shows clear differences among sexes: women experience more frequent relapses, have more inflammatory lesions on MRI and earlier onset of MS compared to men. Male sex, on the other hand, is associated with faster progression and worse outcome with more cerebellar involvement, worse cognition, more gray matter atrophy and more T1 lesions. There are also important changes related to female reproductive cycle with a 3-fold increase in MS prevalence after menarche, a decrease of approximately 70% in relapse rates in the third trimester of pregnancy and an increase in relapse rate in 3-6 months after delivery to nearly three times higher than pre-pregnancy levels. During menopause recent evidence suggest worsening of MS symptoms and probably an increase in disease progression.

Hormonal factors and/or sex chromosomes are thus assumed to be involved in regulating the course of the disease and due to the presence of receptors on immune cells, sex hormones (estrogens, progesterone, prolactin and testosterone) can influence different aspects of immune system function and potentially affect the risk, activity and progression of MS. Sex hormones have different effects depending not only on the concentration but also on the type of target cell and the receptor subtype expressed on a given cell type. Thus, understanding how gender impacts MS requires the elucidation of complex interactions among sex hormones, sex chromosomes, immune response genes, and resident cells of the CNS. We will discuss clinical evidence that shows the impact of hormonal factors in MS. Then, we will try to elucidate the complex hormonal and immunological mechanisms potentially underlying these changes, as well as the current knowledge and new insights into the relationship of sex hormones and resident CNS cells in the context of MS. Understanding those molecular mechanisms may help to provide ways to develop novel and safer treatments for both men and women.

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