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<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Immunol.</journal-id>
<journal-title>Frontiers in Immunology</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Immunol.</abbrev-journal-title>
<issn pub-type="epub">1664-3224</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.3389/fimmu.2024.1384411</article-id>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Immunology</subject>
<subj-group>
<subject>Original Research</subject>
</subj-group>
</subj-group>
</article-categories>
<title-group>
<article-title>A two-years real-word study with fingolimod: early predictors of efficacy and an association between EBNA-1 IgG titers and multiple sclerosis progression</article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname>Dominguez-Mozo</surname>
<given-names>Maria Inmaculada</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Gal&#xe1;n</surname>
<given-names>Victoria</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Rami&#xf3;-Torrent&#xe0;</surname>
<given-names>Llu&#xed;s</given-names>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/567412"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Quiroga</surname>
<given-names>Ana</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Quintana</surname>
<given-names>E.</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/1392585"/>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Villar</surname>
<given-names>Luisa Mar&#xed;a</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/128496"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Costa-Frossard</surname>
<given-names>Lucienne</given-names>
</name>
<xref ref-type="aff" rid="aff7">
<sup>7</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/1155463"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Fern&#xe1;ndez-Velasco</surname>
<given-names>Jos&#xe9; Ignacio</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/1392491"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
<role content-type="https://credit.niso.org/contributor-roles/writing-review-editing/"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname>Villarrubia</surname>
<given-names>Noelia</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/823084"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Garcia-Martinez</surname>
<given-names>Mar&#xed;a Angel</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/874459"/>
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</contrib>
<contrib contrib-type="author">
<name>
<surname>Arroyo</surname>
<given-names>Rafael</given-names>
</name>
<xref ref-type="aff" rid="aff8">
<sup>8</sup>
</xref>
<uri xlink:href="https://loop.frontiersin.org/people/1155470"/>
<role content-type="https://credit.niso.org/contributor-roles/resources/"/>
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</contrib>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Alvarez-Lafuente</surname>
<given-names>Roberto</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="author-notes" rid="fn001">
<sup>*</sup>
</xref>
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</contrib-group>
<aff id="aff1">
<sup>1</sup>
<institution>Grupo de Investigaci&#xf3;n de Factores Ambientales en Enfermedades Degenerativas, Instituto de Investigaci&#xf3;n Sanitaria del Hospital Cl&#xed;nico San Carlos (IdISSC), Red de Enfermedades Inflamatorias (REI)</institution>, <addr-line>Madrid</addr-line>, <country>Spain</country>
</aff>
<aff id="aff2">
<sup>2</sup>
<institution>Servicio de Neurolog&#xed;a, Hospital Universitario de Toledo</institution>, <addr-line>Toledo</addr-line>, <country>Spain</country>
</aff>
<aff id="aff3">
<sup>3</sup>
<institution>Neuroimmunology and Multiple Sclerosis Unit, Girona Biomedical Research Institute (IDIBGI), Doctor Josep Trueta University Hospital and Santa Caterina Hospital, Department of Medical Sciences, University of Girona, Red de Enfermedades Inflamatorias (REI)</institution>, <addr-line>Girona</addr-line>, <country>Spain</country>
</aff>
<aff id="aff4">
<sup>4</sup>
<institution>Neuroimmunology and Multiple Sclerosis Unit (UNIEM), Girona Biomedical Research Institute (IDIBGI), Red de Enfermedades Inflamatorias (REI)</institution>, <addr-line>Girona</addr-line>, <country>Spain</country>
</aff>
<aff id="aff5">
<sup>5</sup>
<institution>Girona Neuroimmunology and Multiple Sclerosis Unit (UNIEM), Girona Biomedical Research Institute (IDIBGI), Department of Medical Sciences, University of Girona</institution>, <addr-line>Girona</addr-line>, <country>Spain</country>
</aff>
<aff id="aff6">
<sup>6</sup>
<institution>Servicio de Inmunolog&#xed;a, Hospital Universitario Ram&#xf3;n y Cajal, Red de Enfermedades Inflamatorias (REI)</institution>, <addr-line>Madrid</addr-line>, <country>Spain</country>
</aff>
<aff id="aff7">
<sup>7</sup>
<institution>Servicio de Neurolog&#xed;a, Hospital Universitario Ram&#xf3;n y Cajal, Red de Enfermedades Inflamatorias (REI)</institution>, <addr-line>Madrid</addr-line>, <country>Spain</country>
</aff>
<aff id="aff8">
<sup>8</sup>
<institution>Departamento de Neurolog&#xed;a, Hospital Universitario Quironsalud Madrid, Red Espa&#xf1;ola de Esclerosis M&#xfa;ltiple (REEM)</institution>, <addr-line>Madrid</addr-line>, <country>Spain</country>
</aff>
<author-notes>
<fn fn-type="edited-by">
<p>Edited by: Gunnar Houen, University of Copenhagen, Denmark</p>
</fn>
<fn fn-type="edited-by">
<p>Reviewed by: Peter A. Maple, Nottingham University Hospitals NHS Trust, United Kingdom</p>
<p>Nicole Trier, Rigshospitalet Glostrup, Denmark</p>
</fn>
<fn fn-type="corresp" id="fn001">
<p>*Correspondence: Roberto Alvarez-Lafuente, <email xlink:href="mailto:ralvarezlafuente@yahoo.es">ralvarezlafuente@yahoo.es</email>
</p>
</fn>
</author-notes>
<pub-date pub-type="epub">
<day>07</day>
<month>06</month>
<year>2024</year>
</pub-date>
<pub-date pub-type="collection">
<year>2024</year>
</pub-date>
<volume>15</volume>
<elocation-id>1384411</elocation-id>
<history>
<date date-type="received">
<day>09</day>
<month>02</month>
<year>2024</year>
</date>
<date date-type="accepted">
<day>23</day>
<month>05</month>
<year>2024</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2024 Dominguez-Mozo, Gal&#xe1;n, Rami&#xf3;-Torrent&#xe0;, Quiroga, Quintana, Villar, Costa-Frossard, Fern&#xe1;ndez-Velasco, Villarrubia, Garcia-Martinez, Arroyo and Alvarez-Lafuente</copyright-statement>
<copyright-year>2024</copyright-year>
<copyright-holder>Dominguez-Mozo, Gal&#xe1;n, Rami&#xf3;-Torrent&#xe0;, Quiroga, Quintana, Villar, Costa-Frossard, Fern&#xe1;ndez-Velasco, Villarrubia, Garcia-Martinez, Arroyo and Alvarez-Lafuente</copyright-holder>
<license xlink:href="http://creativecommons.org/licenses/by/4.0/">
<p>This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</p>
</license>
</permissions>
<abstract>
<sec>
<title>Background</title>
<p>Although fingolimod, a sphingosine 1-phosphate receptor agonist, has shown to be an effective treatment reducing relapse rate and also slowing down the disability progression in relapsing-remitting multiple sclerosis (RRMS) patients, it is important to quickly identify those suboptimal responders.</p>
</sec>
<sec>
<title>Objective</title>
<p>The main objective was to assess different clinical, radiological, genetic and environmental factors as possible early predictors of response in MS patients treated with fingolimod for 24 months. The secondary objective was to analyze the possible contribution of the environmental factors analyzed to the progression and activity of the disease along the 2-years of follow-up.</p>
</sec>
<sec>
<title>Methods</title>
<p>A retrospective study with 151 patients diagnosed with MS, under fingolimod treatment for 24 months, with serum samples at initiation and six months later, and with clinical and radiological data at initiation and 24 months later, were included in the study. Clinical and radiological variables were collected to establish NEDA-3 (no evidence of disease activity: patients without relapses, disability progression and new T2 lesions or Gd+ lesions) and EDA (evidence of disease activity: patients with relapses and/or progression and/or new T2 lesions or gadolinium-positive [Gd+] lesions) conditions. Human leukocyte antigen II (HLA-II), EBNA-1 IgG and VCA IgG from Epstein-Barr virus (EBV) and antibody titers against Human herpesvirus 6A/B (HHV-6A/B) were also analyzed.</p>
</sec>
<sec>
<title>Results</title>
<p>A total of 151 MS patients fulfilled the inclusion criteria: 27.8% was NEDA-3 (37.5% among those previously treated with high efficacy therapies &gt;24 months). The following early predictors were statistically significantly associated with NEDA-3 condition: sex (male; p=0.002), age at baseline (older; p=0.009), relapses 2-years before fingolimod initiation &#x2264;1 (p=0.010), and absence of Gd+ lesions at baseline (p=0.006). Regarding the possible contribution of the environmental factors included in the study to the activity or the progression of the disease, we only found that EBNA-1 IgG titers decreased in 20.0% of PIRA (progression independent from relapse activity) patients vs. 73.3% of RAW (relapse-associated worsening) patients (p=0.006; O.R. = 11.0).</p>
</sec>
<sec>
<title>Conclusion</title>
<p>MS patients that are male, older, and with a low clinical and radiological activity at fingolimod initiation have a greater probability to reach NEDA-3 condition after two years with this therapy. An intriguing association of EBV with the progression of the disease has also been described, but it should be further study in a larger cohort to confirm these results.</p>
</sec>
</abstract>
<kwd-group>
<kwd>multiple sclerosis</kwd>
<kwd>fingolimod</kwd>
<kwd>Epstein-Barr virus</kwd>
<kwd>human herpesvirus 6</kwd>
<kwd>human leukocyte antigen</kwd>
</kwd-group>
<counts>
<fig-count count="3"/>
<table-count count="3"/>
<equation-count count="0"/>
<ref-count count="42"/>
<page-count count="9"/>
<word-count count="4044"/>
</counts>
<custom-meta-wrap>
<custom-meta>
<meta-name>section-in-acceptance</meta-name>
<meta-value>Multiple Sclerosis and Neuroimmunology</meta-value>
</custom-meta>
</custom-meta-wrap>
</article-meta>
</front>
<body>
<sec id="s1" sec-type="intro">
<label>1</label>
<title>Introduction</title>
<p>Fingolimod is a sphingosine 1-phosphate (S1P) receptor agonist that significantly reduces disease activity in relapsing-remitting multiple sclerosis (RRMS) patients (<xref ref-type="bibr" rid="B1">1</xref>). This oral immune&#x2010;modulatory treatment embodies and degrades the sphingosine&#x2010;1&#x2010;phosphate (S1P) receptor on leukocytes, inhibiting the egress of lymphocytes from lymph nodes. Therefore, this therapy is able to reduce the migration of potential inflammatory cells to the central nervous system; as a consequence, patients under fingolimod treatment present peripheral blood lymphopenia due to the redistribution of leukocytes (<xref ref-type="bibr" rid="B2">2</xref>). Although the U.S. Food and Drug Administration (FDA) approved this treatment for RRMS patients, its use in Europe was restricted to highly active RRMS patients or as escalation after failure to first&#x2010;line disease modifying therapies (DMT) (<xref ref-type="bibr" rid="B3">3</xref>). In the FREEDOMS I study, the 70.4% of MS patients treated with the 0.5mg dose, was free of relapses after 24 months of follow-up (<xref ref-type="bibr" rid="B1">1</xref>); these results were very similar to those of the FREEDOMS II performed later: 71.5% (<xref ref-type="bibr" rid="B4">4</xref>). Regarding real-world studies, results are similar to those obtained in the clinical trials or even better when the percentage of relapse-free patients is analyzed, after two years of fingolimod treatment: 81.9% of 286 Turkish MS patients (<xref ref-type="bibr" rid="B5">5</xref>), 77.4% of 78 Italian MS patients (<xref ref-type="bibr" rid="B6">6</xref>), 74.6% of 167 Spanish MS patients (<xref ref-type="bibr" rid="B7">7</xref>). Therefore, although fingolimod has shown to be an effective treatment reducing relapse rate and also slowing down the disability progression, it is important to quickly identify those suboptimal responders.</p>
<p>With this aim, we performed a retrospective study analyzing different clinical, radiological, genetic and environmental factors as possible early predictors of response in MS patients treated with fingolimod along 24 months. Some clinical factors have been previously related to fingolimod response as early predictors (<xref ref-type="bibr" rid="B8">8</xref>, <xref ref-type="bibr" rid="B9">9</xref>). Regarding genetic factors, they have been searched before in relation to the response to the different DMTs in MS. Pharmacogenomic studies have shown that the human leukocyte antigen (HLA) could help to better identify appropriated candidates to each treatment (<xref ref-type="bibr" rid="B10">10</xref>, <xref ref-type="bibr" rid="B11">11</xref>), although in other occasions not (<xref ref-type="bibr" rid="B12">12</xref>, <xref ref-type="bibr" rid="B13">13</xref>). In fact, a recent paper published in pediatric and adolescent MS patients treated with fingolimod identified different haplotypes that showed a trend towards a more favorable clinical course (<xref ref-type="bibr" rid="B14">14</xref>). Finally, viruses have been proposed as possible biomarkers of response to different DMTs (<xref ref-type="bibr" rid="B15">15</xref>, <xref ref-type="bibr" rid="B16">16</xref>). Viruses like Human herpesvirus 6 (HHV-6) or Epstein-Barr virus (EBV) have been proposed to be actively involved in processes like the activity (<xref ref-type="bibr" rid="B17">17</xref>) or the progression of the disease (<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B19">19</xref>), and therefore, modifications in their antibody levels or in their viral load along the treatment could be identified in relation with these processes. The main objective of this study was to assess all of them, in the same cohort of MS patients treated with fingolimod, in relation to the clinical and radiological response comparing NEDA-3 (no evidence of disease activity: patients without relapses, disability progression and new T2 lesions or Gd+ lesions) and EDA (evidence of disease activity: patients with relapses and/or progression and/or new T2 lesions or Gd+ lesions) patients. The secondary objective was to analyze the possible contribution of the environmental factors analyzed to the progression and activity of the disease along the 2-years of follow-up. Furthermore, in the last years, different S1P receptor agonists have been approved for the treatment of MS patients (<xref ref-type="bibr" rid="B20">20</xref>&#x2013;<xref ref-type="bibr" rid="B22">22</xref>). Thus, the results obtained with fingolimod could be of interest for them, since they largely share the same mechanism of action.</p>
</sec>
<sec id="s2">
<label>2</label>
<title>Methods</title>
<sec id="s2_1">
<label>2.1</label>
<title>Design</title>
<p>This is a retrospective study with the following inclusion criteria: 1) MS patients diagnosed by Poser, 2010 or 2017 McDonald criteria (<xref ref-type="bibr" rid="B23">23</xref>&#x2013;<xref ref-type="bibr" rid="B25">25</xref>); 2) under fingolimod treatment for 24 months; 3) with serum samples collected within a month before starting fingolimod treatment and six months after the first dose; 4) with the following clinical and radiological data at initiation and 24 months later: Expanded disability status scale (EDSS) score, number of relapses, T2 lesions and gadolinium-positive (Gd+) lesions at initiation, and one and two years later.</p>
</sec>
<sec id="s2_2">
<label>2.2</label>
<title>Patients</title>
<p>Patients were recruited from the following hospitals: Hospital Cl&#xed;nico San Carlos (Madrid), Hospital Universitario Doctor Josep Trueta (Gerona) and Hospital Universitario Ram&#xf3;n y Cajal (Madrid). The clinical and radiological data were collected by neurologists and radiologists belonging to the Multiple Sclerosis Units of these hospitals.</p>
</sec>
<sec id="s2_3">
<label>2.3</label>
<title>Ethics statement</title>
<p>This study was approved by the local Ethic Committee of the Hospital Cl&#xed;nico San Carlos (Comit&#xe9; &#xc9;tico de Investigaci&#xf3;n Cl&#xed;nica del Hospital Cl&#xed;nico San Carlos). All the patients recruited received and signed a written informed consent. All experiments were performed in accordance with relevant guidelines and regulations.</p>
</sec>
<sec id="s2_4">
<label>2.4</label>
<title>Response criteria</title>
<p>According to the pre-treatment EDSS score, we defined the progression as the following increases after 24 months of fingolimod treatment: 1) EDSS=0: &#x2265;1.5 points; 2) EDSS &#x2265;1 and &#x2264;5: &#x2265;1 point; 3) EDSS &#x2265;5.5: &#x2265;0.5 points. We also analyzed two different variables related to the progression: RAW (relapse-associated worsening: patients with progression and with at least one relapse during the two years of follow-up under fingolimod treatment) and PIRA (progression independent from relapse activity: patients with progression and without relapses during the two years of follow-up under fingolimod treatment). Although they are non-mutually exclusive drivers for long-term disability, we considered PIRA and RAW as two competing outcomes (<xref ref-type="bibr" rid="B26">26</xref>). Relapses were defined as a worsening of neurological impairment or an appearance of a new symptom or abnormality attributable to MS; they lasted at least 24 hours and they were preceded by stability period of at least 1 month. Regarding magnetic resonance imaging (MRI), it was performed one month prior fingolimod treatment onset and 1 and 2 years after starting this therapy in 1.5T scanners; a previous published protocol was followed (<xref ref-type="bibr" rid="B27">27</xref>). The sequences collected for this study were; axial fluid-attenuated inversion recovery (FLAIR) T2, axial proton density T2-weighted imaging, axial T2-weighted imaging, and T1-weighted imaging with gadolinium (Gd) enhancement. With previous definitions, these were the response criteria: clinical response (absence of disability progression and relapses), NEDA-3 (no evidence of disease activity: patients without relapses, disability progression and new T2 lesions or Gd+ lesions), and EDA (evidence of disease activity: patients with relapses and/or progression and/or new T2 lesions or Gd+ lesions).</p>
</sec>
<sec id="s2_5">
<label>2.5</label>
<title>Researched variables</title>
<p>The following variables were analyzed: 1) Clinical: sex, age at recruitment, age at disease onset, disease duration, number of relapses two years before the recruitment, EDSS score at treatment initiation and previous treatments. Therapies were classified as: moderate efficacy treatments (MET: beta-interferon, glatiramer acetate, dimethyl fumarate and teriflunomide) and high efficacy treatments (HET: natalizumab, mitoxantrone, azathioprine) 2) Radiological: T2 and Gd+ lesions at recruitment and after one and two years of fingolimod treatment. 3) Genetic: HLA-II. 4) Viral: antibody responses to EBV (EBNA-1 IgG and VCA IgG) and HHV-6 IgG and IgM antibody titers at fingolimod initiation; based on previous published results of our group we also analyzed the change in the antibody titers between the baseline and the six month sample (<xref ref-type="bibr" rid="B15">15</xref>, <xref ref-type="bibr" rid="B17">17</xref>).</p>
</sec>
<sec id="s2_6">
<label>2.6</label>
<title>DNA extraction</title>
<p>DNA spin column technique of QIAamp DNA Blood Mini Kit (QIAGEN. Hilden. Germany) was used to isolate total DNA from 0.2&#xa0;ml of blood, following the manufacturer&#x2019;s instructions.</p>
</sec>
<sec id="s2_7">
<label>2.7</label>
<title>HLA genotyping</title>
<p>The genotyping of the alleles belonging to HLA class II (DR, DQA and DQB) was carried out using the rSSO-PCR technique (sequence-specific oligonucleotide reverse PCR). LABType&#x2122; One Lambda kits (Thermo Fisher Scientific, Waltham, MA, USA) were used following the manufacturer&#x2019;s instructions. The detection was carried out on a FLEXMAP 3D&#x2122; device (Luminex Corporation, Austin, TX, USA), whose detection is based on Luminex&#x2122; technology.</p>
</sec>
<sec id="s2_8">
<label>2.8</label>
<title>ELISA</title>
<p>Commercial tests for the detection of EBNA-1 and VCA IgG (Trinity Biotech, USA) and HHV-6A/B IgG and IgM (Vidia, Ltd., Czech Republic) were used in an automated ELISA processing system (DS2, Dynex Technologies, USA), following the manufacturer&#x2019;s instructions. Results were expressed in artificial units (AU): index value * 10 (index value = sample absorbance/cut-off value) (<xref ref-type="bibr" rid="B15">15</xref>, <xref ref-type="bibr" rid="B17">17</xref>). Each sample was analyzed in duplicate for each test. Doubtful samples (between 9 and 11 AU) were tested again; they were considered negative samples if they remained under 11 AU at the new analysis.</p>
</sec>
<sec id="s2_9">
<label>2.9</label>
<title>Statistical analysis</title>
<p>To test differences in categorical variables we used the chi-square or two-tailed Fisher&#x2019;s exact test. To analyze differences in continuous variables the Kruskall-Wallis test or the Wilcoxon rank-sum test were used. Association between clinical, radiological, genetic and environmental factors as possible early predictors and clinical outcomes (activity and/or progression of the disease), alone or in combination (NEDA-3/EDA) was studied with a non-parametric test (U Mann-Whitney). Bonferroni correction was performed when multiple comparisons were made. P-values &lt;0.05 were considered as statistically significant. All statistical analysis were performed using Statistical Package for Social Sciences, version 15.0 (IBM SPSS, Inc, Chicago, IL, USA).</p>
</sec>
</sec>
<sec id="s3" sec-type="results">
<label>3</label>
<title>Results</title>
<sec id="s3_1">
<label>3.1</label>
<title>Patients recruited for the study and demographic characteristics of the population study</title>
<p>A total of 151 MS patients fulfilled all the inclusion criteria of the study. Their characteristics are shown in <xref ref-type="table" rid="T1">
<bold>Table&#xa0;1</bold>
</xref>.</p>
<table-wrap id="T1" position="float">
<label>Table&#xa0;1</label>
<caption>
<p>Demographical characteristics of the patients included in the study at the onset of fingolimod treatment.</p>
</caption>
<table frame="hsides">
<tbody>
<tr>
<td valign="middle" align="left">Sex</td>
<td valign="middle" align="right">N</td>
</tr>
<tr>
<td valign="middle" align="right">Males</td>
<td valign="middle" align="right">46</td>
</tr>
<tr>
<td valign="middle" align="right">Females</td>
<td valign="middle" align="right">105</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Age [years, med (P25-P75)]</bold>
</td>
<td valign="middle" align="right">38.6 (33.0&#x2013;45.0)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Age at disease onset [years, med (P25-P75)]</bold>
</td>
<td valign="middle" align="right">26.0 (22.0&#x2013;31.0)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Disease duration at fingolimod onset [months, med (P25-P75)]</bold>
</td>
<td valign="middle" align="right">125.0 (75.0&#x2013;190.9)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>EDSS [med (P25-P75)]</bold>
</td>
<td valign="middle" align="right">3.0 (2.0&#x2013;4.0)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Relapses 2 years before [med (P25-P75)]</bold>
</td>
<td valign="middle" align="right">1.0 (0.0&#x2013;2.0)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Patients with at least one relapse 2 years before [n/N(%)]</bold>
</td>
<td valign="middle" align="right">102/151 (67.5%)</td>
</tr>
<tr>
<td valign="middle" align="left">
<bold>Treatment na&#xef;ve (N)</bold>
</td>
<td valign="middle" align="right">9</td>
</tr>
<tr>
<td valign="middle" align="left">Last treatment before fingolimod onset</td>
<td valign="middle" align="right">N</td>
</tr>
<tr>
<td valign="middle" align="right">Glatiramer acetate</td>
<td valign="middle" align="right">27</td>
</tr>
<tr>
<td valign="middle" align="right">Interferon beta</td>
<td valign="middle" align="right">38</td>
</tr>
<tr>
<td valign="middle" align="right">Mitoxantrone</td>
<td valign="middle" align="right">3</td>
</tr>
<tr>
<td valign="middle" align="right">Azathioprine</td>
<td valign="middle" align="right">1</td>
</tr>
<tr>
<td valign="middle" align="right">Natalizumab</td>
<td valign="middle" align="right">71</td>
</tr>
<tr>
<td valign="middle" align="right">Dimethyl fumarate</td>
<td valign="middle" align="right">1</td>
</tr>
<tr>
<td valign="middle" align="right">Teriflunomide</td>
<td valign="middle" align="right">1</td>
</tr>
<tr>
<td valign="middle" align="right">Duration of the last treatment [months, med (P25-P75)]</td>
<td valign="middle" align="right">29.0 (16.5&#x2013;47.5)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>(med, median; P25, 25th percentile; P75, 75th percentile; EDSS, Expanded Disability Status Scale)</p>
</fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec id="s3_2">
<label>3.2</label>
<title>Clinical and radiological response after two years of fingolimod treatment</title>
<p>The 34.4% (52/151) of MS patients suffered relapses after two years of fingolimod treatment vs. 67.5% (102/151) two years prior to fingolimod onset (49% of reduction). The 19.9% (30/151) of MS patients experienced progression according to the progression criteria above mentioned: 50% of them were PIRA (15/30) and 50% were RAW (15/30). Regarding the MRI studies, the 38.4% (58/151) of patients had new T2 lesions after 24-months of fingolimod treatment; the 21.2% (32/151) had Gd+ lesions at 12-month and/or 24-month MRI. According to our response criteria, the 55% (83/151) could be considered as clinical responders and the 27.8% (42/151) as NEDA-3 after two years of fingolimod treatment.</p>
</sec>
<sec id="s3_3">
<label>3.3</label>
<title>Early clinical and radiological variables</title>
<p>When we compared MS patients with NEDA-3 vs. those with EDA, the following early predictors were statistical significantly associated with NEDA-3 condition (<xref ref-type="fig" rid="f1">
<bold>Figure&#xa0;1</bold>
</xref>): sex (male; p=0.002), age at baseline (older; p=0.009), relapses 2-years before fingolimod initiation &#x2264;1 (p=0.010), and absence of Gd+ lesions at baseline (p=0.006). Thus, the 71.4% of those MS patients with these four early predictors were NEDA-3 vs. the 6.7% among those MS patients without any of them. Since most of the MS patients had been previously treated (<xref ref-type="table" rid="T1">
<bold>Table&#xa0;1</bold>
</xref>), we analyzed their possible relation with the number of relapses two years before and with the number of Gd+ lesions at fingolimod initiation. We found statistically significant differences when we compared MS patients treated with MET and HET for more than 24 months (<xref ref-type="table" rid="T2">
<bold>Table&#xa0;2</bold>
</xref>): a higher proportion of MS patients previously treated with HET had &#x2264;1 relapses 2-years before (p=0.003; O.R. = 5.3) and no Gd+ lesions (p=&lt;0.0001; O.R. = 12.3) at fingolimod initiation. However, when we analyzed the effect of MET and HET treatments prior to fingolimod initiation on NEDA-3 condition, we did not find any statistically significant difference (<xref ref-type="table" rid="T3">
<bold>Table&#xa0;3</bold>
</xref>).</p>
<fig id="f1" position="float">
<label>Figure&#xa0;1</label>
<caption>
<p>Comparison of clinical and radiological variables between NEDA-3 and EDA patients at recruitment (p values were calculated from Chi-square test/Fisher&#x2019;s exact test for categorical variables and with the Kruskall-Wallis test for the continuous variables). Lines inside the graphs shows the mean value. (GraphPad Prism 5.0) n.s., not significant.</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fimmu-15-1384411-g001.tif"/>
</fig>
<table-wrap id="T2" position="float">
<label>Table&#xa0;2</label>
<caption>
<p>Effect of previous treatments on the number of relapses two-years before fingolimod initiation and on the number of Gd+ lesions at baseline samples.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="middle" align="center" rowspan="2"/>
<th valign="middle" colspan="4" align="center">Treated 3&#x2013;12 months</th>
<th valign="middle" colspan="4" align="center">Treated 13&#x2013;24 months</th>
<th valign="top" colspan="4" align="center">Treated &gt;24 months</th>
</tr>
<tr>
<th valign="middle" align="center">MET</th>
<th valign="middle" align="center">HET</th>
<th valign="middle" align="center">p*</th>
<th valign="middle" align="center">O.R.**</th>
<th valign="middle" align="center">MET</th>
<th valign="middle" align="center">HET</th>
<th valign="middle" align="center">p*</th>
<th valign="middle" align="center">O.R.**</th>
<th valign="middle" align="center">MET</th>
<th valign="middle" align="center">HET</th>
<th valign="middle" align="center">p*</th>
<th valign="middle" align="center">O.R.**</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" align="center">
<bold>patients with &#x2264;1 relapse</bold> <break/><bold>2-years before fingolimod initiation</bold>
</td>
<td valign="middle" align="center">6/16 (37.5%)</td>
<td valign="middle" align="center">2/8 (25.0%)</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">5/16 (31.3%)</td>
<td valign="middle" align="center">11/17 (64.7%)</td>
<td valign="middle" align="center">0.06</td>
<td valign="middle" align="center">4.0</td>
<td valign="middle" align="center">18/32 (56.3%)</td>
<td valign="middle" align="center">41/47 (87.2%)</td>
<td valign="middle" align="center">0.003</td>
<td valign="middle" align="center">5.3</td>
</tr>
<tr>
<td valign="middle" align="center">
<bold>Mean of relapses 2-years before fingolimod initiation</bold>
</td>
<td valign="middle" align="center">2.3</td>
<td valign="middle" align="center">2.4</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">1.9</td>
<td valign="middle" align="center">1.6</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">1.3</td>
<td valign="middle" align="center">0.6</td>
<td valign="middle" align="center">0.002</td>
<td valign="middle" align="center">
</td>
</tr>
<tr>
<td valign="middle" align="center">
<bold>patients without Gd+ lesions at baseline sample</bold>
</td>
<td valign="middle" align="center">11/16 (68.8%)</td>
<td valign="middle" align="center">5/8 (62.5%)</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">13/16 (81.3%)</td>
<td valign="middle" align="center">13/17 (76.5%)</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">13/32 (40.6%)</td>
<td valign="middle" align="center">42/47 (89.4%)</td>
<td valign="middle" align="center">&lt;0.0001</td>
<td valign="middle" align="center">12.3</td>
</tr>
<tr>
<td valign="middle" align="center">
<bold>Mean of Gd+ lesions at baseline sample</bold>
</td>
<td valign="middle" align="center">0.5</td>
<td valign="middle" align="center">1.0</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">0.9</td>
<td valign="middle" align="center">0.6</td>
<td valign="middle" align="center">n.s.</td>
<td valign="middle" align="center">
</td>
<td valign="middle" align="center">0.5</td>
<td valign="middle" align="center">0.0</td>
<td valign="middle" align="center">0.002</td>
<td valign="middle" align="center">
</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>*p values were calculated from Chi-square test/Fisher&#x2019;s exact test. **Odds Ratios. MET, moderate efficacy treatments (beta-interferon, glatiramer acetate, dimethyl fumarate and teriflunomide). HET, high efficacy treatments (natalizumab, mitoxantrone, azathioprine). n.s., not significant.</p>
</fn>
</table-wrap-foot>
</table-wrap>
<table-wrap id="T3" position="float">
<label>Table&#xa0;3</label>
<caption>
<p>Effect of previous treatments on NEDA-3 condition.</p>
</caption>
<table frame="hsides">
<thead>
<tr>
<th valign="top" align="center">Na&#xef;ve MS patients</th>
<th valign="middle" rowspan="2" align="center">Treated MS patients</th>
<th valign="top" align="center">0&#x2013;12 months</th>
<th valign="middle" align="center">13&#x2013;24 months</th>
<th valign="top" align="center">25&#x2013;48 months</th>
<th valign="middle" align="center">&gt;48 months</th>
<th valign="bottom" rowspan="2" align="center">p* (O.R.**)<break/>MET vs. HET</th>
</tr>
<tr>
<th valign="top" align="center">NEDA-3</th>
<th valign="top" align="center">NEDA-3</th>
<th valign="middle" align="center">NEDA-3</th>
<th valign="top" align="center">NEDA-3</th>
<th valign="middle" align="center">NEDA-3</th>
</tr>
</thead>
<tbody>
<tr>
<td valign="middle" rowspan="2" align="center">3/9 (33.3%)</td>
<td valign="middle" align="center">
<bold>MET</bold>
</td>
<td valign="top" align="center">3/19<break/>(15.8%)</td>
<td valign="middle" align="center">5/16<break/>(31.3%)</td>
<td valign="top" align="center">3/17<break/>(17.6%)</td>
<td valign="middle" align="center">3/15<break/>(20.0%)</td>
<td valign="middle" rowspan="2" align="center">0.100<break/>(1.9)</td>
</tr>
<tr>
<td valign="middle" align="center">
<bold>HET</bold>
</td>
<td valign="top" align="center">1/11<break/>(9.1%)</td>
<td valign="middle" align="center">6/17<break/>(35.3%)</td>
<td valign="top" align="center">11/31<break/>(35.5%)</td>
<td valign="middle" align="center">7/16<break/>(43.8%)</td>
</tr>
<tr>
<td valign="top" rowspan="2" align="center"/>
<td valign="middle" align="center">
<bold>p*</bold>
<break/>
<bold>(O.R.**)</bold>
</td>
<td valign="top" align="center">0.607<break/>(1.9)</td>
<td valign="middle" align="center">0.806<break/>(1.2)</td>
<td valign="top" align="center">0.202<break/>(2.6)</td>
<td valign="middle" align="center">0.166<break/>(3.1)</td>
<td valign="top" rowspan="2" align="center"/>
</tr>
<tr>
<td valign="middle" align="center">
<bold>p*</bold>
<break/>
<bold>(O.R.**)</bold>
</td>
<td valign="top" colspan="2" align="center">0.843<break/>(1.1)</td>
<td valign="top" colspan="2" align="center">0.069<break/>(2.7)</td>
</tr>
</tbody>
</table>
<table-wrap-foot>
<fn>
<p>*p values were calculated from Chi-square test/Fisher&#x2019;s exact test. **Odds Ratios. MET, moderate efficacy treatments (beta-interferon, glatiramer acetate, dimethyl fumarate and teriflunomide). HET, high efficacy treatments (natalizumab, mitoxantrone, azathioprine).</p>
</fn>
</table-wrap-foot>
</table-wrap>
</sec>
<sec id="s3_4">
<label>3.4</label>
<title>HLA-II as early biomarker of response</title>
<p>After Bonferroni correction, we only found statistically significant associations for DR4 carriers: most of them were clinical responders (p=0.008; O.R. = 3.4) and none of them progressed after two-years of follow-up (p=0.006; O.R. = 15.9). However, the statistical significance was not reached when analyzing the NEDA-3 condition (p=0.09; O.R. = 2.6).</p>
</sec>
<sec id="s3_5">
<label>3.5</label>
<title>Viral serologies and the response to fingolimod treatment</title>
<p>We did not find statistically significant associations for EBNA-1 IgG, VCA IgG or HHV-6 IgG and IgM titers at baseline with NEDA-3 condition (see <xref ref-type="fig" rid="f2">
<bold>Figure&#xa0;2A</bold>
</xref>). The change in the antibody titers between the baseline and the six month sample was not associated either (<xref ref-type="fig" rid="f2">
<bold>Figure&#xa0;2B</bold>
</xref>); we did not consider variations &#x2264;4.8% (our inter-assay coefficient of variation). Finally we also analyzed the possible association of the baseline antibody titers and the antibody titers variation between the baseline sample and the six month sample with the progression (yes vs. no, and PIRA vs. RAW) and with the activity of the disease (with relapses vs. without relapses, and with Gd+ lesions vs. without Gd+ lesions), after 2-years of follow-up with fingolimod treatment. Again, we did not consider variations &#x2264;4.8% (our inter-assay coefficient of variation). After Bonferroni correction for multiple comparisons, we only found one statistically significant association when we compared PIRA and RAW patients: we found that EBNA-1 IgG titers decreased in 3/15 (20.0%) PIRA patients after two-years of fingolimod therapy vs. 11/15 (73.3%) RAW patients (p=0.006; O.R. = 11.0) (<xref ref-type="fig" rid="f3">
<bold>Figure&#xa0;3</bold>
</xref>).</p>
<fig id="f2" position="float">
<label>Figure&#xa0;2</label>
<caption>
<p>
<bold>(A)</bold>. EBNA-1 IgG, VCA IgG or HHV-6 IgG and IgM titers at baseline in NEDA-3 and EDA patients. <bold>(B)</bold> Variation in the antibody titers between NEDA-3 and EDA patients (we did not consider variations &#x2264;4.8%, our inter-assay coefficient of variation). Significations with the two-tailed t-test are shown (n.s., not significant). Lines inside the graphs shows the mean value plus the standard deviation. (GraphPad Prism 5.0).</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fimmu-15-1384411-g002.tif"/>
</fig>
<fig id="f3" position="float">
<label>Figure&#xa0;3</label>
<caption>
<p>EBNA-1 IgG variation between the baseline sample and the six month sample in PIRA and RAW patients. Mean values plus standard deviation (GraphPad Prism 5.0).</p>
</caption>
<graphic mimetype="image" mime-subtype="tiff" xlink:href="fimmu-15-1384411-g003.tif"/>
</fig>
</sec>
</sec>
<sec id="s4" sec-type="discussion">
<label>4</label>
<title>Discussion</title>
<p>Identifying early predictors of response in MS is essential for improving patient outcomes, optimizing treatment strategies, and advancing our understanding of the disease. It holds the potential to transform MS care by enabling personalized, timely, and effective interventions, ultimately benefiting both patients and the healthcare system as a whole. With this purpose, we analyzed different clinical, radiological, genetic and serological variables to search for early predictors of NEDA-3 condition after two-years of treatment with fingolimod.</p>
<p>Patients recruited for this multicenter study showed a lower proportion of NEDA-3 condition compared to most of the studies performed in real-world: 56.6% (<xref ref-type="bibr" rid="B28">28</xref>), 44% (<xref ref-type="bibr" rid="B29">29</xref>), 48.3% (<xref ref-type="bibr" rid="B8">8</xref>), 44% (<xref ref-type="bibr" rid="B30">30</xref>), but similar to other real-world studies, 22% (<xref ref-type="bibr" rid="B31">31</xref>), and <italic>post-hoc</italic> analyses of randomized clinical trials, 29.5% (<xref ref-type="bibr" rid="B32">32</xref>), and 31.0% (<xref ref-type="bibr" rid="B33">33</xref>). The variability in NEDA-3 proportion could be explained by the heterogeneity of MS patients included in the different real-world studies. In our cohort, only 9/151 (6.0%) were treatment na&#xef;ve, and previous studies published a higher proportion of NEDA-3 condition in treatment na&#xef;ve patients treated with fingolimod (<xref ref-type="bibr" rid="B28">28</xref>). Regarding the other patients of our study, 67/151 (44.3%) were treated with MET (median: 25.0 months; range: 1&#x2013;192 months) and 75/151 (49.7%) were treated with HET (median: 32.0 months; range: 1&#x2013;92 months). As it has been previously described (<xref ref-type="bibr" rid="B28">28</xref>), previous DMTs influence the NEDA-3 proportion of MS patients treated with fingolimod. In our study, although a clear effect of previous treatments was described on the number of relapses and Gd+ lesions prior fingolimod initiation (<xref ref-type="table" rid="T2">
<bold>Table&#xa0;2</bold>
</xref>), no statistically significant differences were found in relation to the NEDA-3 condition (<xref ref-type="table" rid="T3">
<bold>Table&#xa0;3</bold>
</xref>). However, trends were found when we compared MET vs. HET, and also when we compared MS patients treated with MET and HET for more than two years, showing that not only prior treatments but also their duration may influence the subsequent clinical response to fingolimod.</p>
<p>In our study, the following early predictors were statistically significant associated with NEDA-3 condition: sex (male), age at baseline (older), relapses 2-years before fingolimod initiation &#x2264;1, and absence of Gd+ lesions at baseline. The last three have been yet previously reported as early predictors of fingolimod treatment (<xref ref-type="bibr" rid="B8">8</xref>), together with lower EDSS score at baseline (<xref ref-type="bibr" rid="B9">9</xref>). However, previous studies have not found significant differences in treatment response between males and females taking fingolimod. In our cohort, 21/46 (45.7%) males were NEDA-3 vs. 21/105 (20.0%) females. No differences in previous treatments were found between males and females, and we did not find any difference for the other three variables between them either. Further studies will be needed to find a possible explanation.</p>
<p>Regarding the genetic variables analyzed, we found that DR4 carriers were better clinical responders and none of them progressed after two-years of follow-up. There is only one previous study analyzing different genetic data to find predictors of response to fingolimod (<xref ref-type="bibr" rid="B20">20</xref>), but none analyzing HLA apart from one searching for HLA alleles that differentially regulate John Cunningham (JC) virus antibody serostatus in MS patients treated with fingolimod (<xref ref-type="bibr" rid="B34">34</xref>). The term DR4 refers to the HLA-DRB1*04, that is associated with an increased risk of developing MS, mainly in some Mediterranean populations (<xref ref-type="bibr" rid="B35">35</xref>). Regarding MS, HLA-DRB1*04 alleles have been associated with primary progressive MS (PP-MS) (<xref ref-type="bibr" rid="B36">36</xref>); however, other studies could only either suggest a non-significant trend to a positive association of HLA-DRB1*04 alleles with PP-MS (<xref ref-type="bibr" rid="B37">37</xref>), or no effect at all (<xref ref-type="bibr" rid="B38">38</xref>). The possible association of HLA-DRB1*04 with PP-MS and the results of our study showing absence of progression in DR4 carriers treated with fingolimod, suggest further studies to solve this intriguing association.</p>
<p>Finally, we described an interesting association between EBNA-1 IgG titers and the progression of the disease. The 73.3% of RAW patients experienced a decrease of those antiviral titers between baseline visit and six-month visit after two years of fingolimod treatment vs. only 20.0% of PIRA patients. EBV is currently considered one of the main risk factors in MS (<xref ref-type="bibr" rid="B39">39</xref>). A recent study showed that an immune response against EBV could turn against the host, triggering disease progression (<xref ref-type="bibr" rid="B40">40</xref>). Different studies have supported the role of EBV in the progression of the disease in the last years (<xref ref-type="bibr" rid="B41">41</xref>). Here we first describe a different behavior of EBV depending on the different progression of the disease. We could speculate that EBV would be associated to those mechanisms involved in the progression of the disease that are independent of relapse activity, also referred to as smoldering MS (<xref ref-type="bibr" rid="B42">42</xref>), rather than in the relapse-associated worsening. The re-analysis of previous clinical trials or observational studies from the perspective here described of a different behavior of EBV in PIRA and RAW patients could be very valuable.</p>
<p>However, one limitation of the study could be its retrospective design. Thus, we should be aware about possible selection bias of the patients recruited for the study, and therefore, the level of evidence could be inferior compared with prospective studies. Other limitation of the study, related to one of the significant results obtained, could be the small size of the cohorts resulting from dividing those MS patients who progressed after two years of fingolimod treatment, between PIRA and RAW. It would also have been desirable to have a measurement of the EBV antibody titers in serum samples collected at 24 months to confirm the titer variations obtained at the 6 month visit.</p>
<p>In conclusion, here we describe four early predictors that could help to identify optimal responders to fingolimod treatment. Thus, according to the current study, MS patients that are male, older, and with a low clinical and radiological activity at fingolimod initiation have a greater probability to reach NEDA-3 condition after two years with this therapy. An intriguing association of EBV with the progression of the disease has also been described, but it should be further study in a larger cohort to confirm these results.</p>
</sec>
<sec id="s5" sec-type="data-availability">
<title>Data availability statement</title>
<p>The original contributions presented in the study are included in the article/<xref ref-type="supplementary-material" rid="SM1">
<bold>Supplementary Material</bold>
</xref>. Further inquiries can be directed to the corresponding author.</p>
</sec>
<sec id="s6" sec-type="ethics-statement">
<title>Ethics statement</title>
<p>The studies involving humans were approved by Comit&#xe9; &#xc9;tico de Investigaci&#xf3;n Cl&#xed;nica del Hospital Cl&#xed;nico San Carlos. The studies were conducted in accordance with the local legislation and institutional requirements. The participants provided their written informed consent to participate in this study.</p>
</sec>
<sec id="s7" sec-type="author-contributions">
<title>Author contributions</title>
<p>MD-M: Formal analysis, Investigation, Methodology, Writing &#x2013; original draft, Writing &#x2013; review &amp; editing, Validation. VG: Writing &#x2013; review &amp; editing, Resources. LR-T: Resources, Writing &#x2013; review &amp; editing. AQ: Resources, Writing &#x2013; review &amp; editing. EQ: Resources, Writing &#x2013; review &amp; editing. LV: Resources, Writing &#x2013; review &amp; editing. LC-F: Resources, Writing &#x2013; review &amp; editing. JF: Resources, Writing &#x2013; review &amp; editing. NV: Resources, Writing &#x2013; review &amp; editing. AM: Investigation, Methodology, Writing &#x2013; review &amp; editing. RA: Resources, Writing &#x2013; review &amp; editing. RA-L: Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Supervision, Writing &#x2013; original draft, Writing &#x2013; review &amp; editing.</p>
</sec>
</body>
<back>
<sec id="s8" sec-type="funding-information">
<title>Funding</title>
<p>The author(s) declare that financial support was received for the research, authorship, and/or publication of this article. AM has a technician contract from &#x201c;REI: Red de Enfermedades Inflamatorias&#x201d; (RD21/0002/0038). This work was financially supported by Ministerio de Ciencia e Innovaci&#xf3;n (Proyectos de generaci&#xf3;n de conocimiento)-Fondo Europeo de Desarrollo Regional (Feder) (PID2021-126041OB-I00) and &#x201c;Fundaci&#xf3;n LAIR&#x201d;.</p>
</sec>
<sec id="s9" sec-type="COI-statement">
<title>Conflict of interest</title>
<p>VG has received support for attending meetings and speaking honoraria from Merck, Biogen, Novartis and Sanofi-Genzyme. LR-T has received compensation for consulting services and speaking honoraria from Biogen, Novartis, Bayer, Merck, Sanofi, Genzyme, Janssen, Horizon, Teva Pharmaceutical Industries Ltd, Almirall. AQ has received travel support from Merck and Novartis for conference attendance. LV has served at scientific advisory boards, participated in meetings sponsored by, received speaking honoraria or travel funding or research grants from Roche, Sanofi, Merck, Biogen, Bristol Myers, and Novartis. LC-F reports compensation for consulting services and speaker honoraria from Biogen, Bristol Myers Squibb, Janssen, Merck-Serono, Novartis, Sanofi, Roche, and Teva. RA has been a speaker or has participated in the advisory board of Novartis, Teva, Roche, Bristol, Janssen, Biogen, Merck and Sanofi-Genzyme. RA-L has received support for attending meetings from Biogen, Merck, Novartis and Sanofi-Genzyme.</p>
<p>The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
<p>The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.</p>
</sec>
<sec id="s10" sec-type="disclaimer">
<title>Publisher&#x2019;s note</title>
<p>All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.</p>
</sec>
<sec id="s11" sec-type="supplementary-material">
<title>Supplementary material</title>
<p>The Supplementary Material for this article can be found online at: <ext-link ext-link-type="uri" xlink:href="https://www.frontiersin.org/articles/10.3389/fimmu.2024.1384411/full#supplementary-material">https://www.frontiersin.org/articles/10.3389/fimmu.2024.1384411/full#supplementary-material</ext-link>
</p>
<supplementary-material xlink:href="Table_1.xlsx" id="SM1" mimetype="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"/>
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