{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T12:47:39Z","timestamp":1775047659228,"version":"3.50.1"},"reference-count":19,"publisher":"SAGE Publications","issue":"1","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"},{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.sagepub.com\/page\/policies\/text-and-data-mining-license"}],"content-domain":{"domain":["journals.sagepub.com"],"crossmark-restriction":true},"short-container-title":["Multiple Sclerosis Journal \u2013 Experimental, Translational and Clinical"],"published-print":{"date-parts":[[2026,1]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Natalizumab is effective for relapsing MS but may trigger anti-natalizumab antibodies (ANZ) that neutralise drug activity and increase reactions. Trials report persistent antibodies in \u223c6% and overall prevalence between 4% and 14%, but real-world burden and optimal testing remain uncertain. We assessed ANZ prevalence, timing, and correlates, comparing systematic with indication-driven testing.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Single-centre retrospective cohort of natalizumab-treated patients with \u22651 ANZ test. Testing followed routine care: systematic screening at months 6\/12\/18 or testing triggered by suspected inefficacy or infusion reactions. Clinical\/MRI data were abstracted; time to positivity was used in Kaplan\u2013Meier; predictors were assessed using multivariable logistic regression.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Among 182 patients (348 tests), ANZ were detected in nine (4.9%; four persistent and five transient), all within the first 12 infusions. Positivity differed by indication (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009=\u20090.005): suspected inefficacy 10.5% (4\/38), systematic screening 1.6% (5\/304), post-reaction testing 0% (0\/6). Within suspected inefficacy, MRI activity was more strongly associated with positivity than symptoms alone (\n                      <jats:italic toggle=\"yes\">p<\/jats:italic>\n                      \u2009=\u20090.04). In multivariable models, suspected inefficacy was the only independent predictor; adding indication improved discrimination (AUC 0.74 vs. 0.56).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>In routine care, ANZ positivity is uncommon and occurs early. Indication-driven testing \u2013 especially when prompted by new MRI lesions \u2013 yields greater diagnostic value than routine screening of clinically stable patients, supporting a selective, context-driven approach to ANZ monitoring.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1177\/20552173261438267","type":"journal-article","created":{"date-parts":[[2026,3,30]],"date-time":"2026-03-30T13:03:50Z","timestamp":1774875830000},"update-policy":"https:\/\/doi.org\/10.1177\/sage-journals-update-policy","source":"Crossref","is-referenced-by-count":0,"title":["Clinical relevance and predictors of anti-natalizumab antibodies in multiple sclerosis: A real-world retrospective cohort study"],"prefix":"10.1177","volume":"12","author":[{"given":"Michael","family":"Levy","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ysoline","family":"Beigneux","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6969-9943","authenticated-orcid":false,"given":"Thomas","family":"Roux","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mathieu","family":"Mossad","sequence":"additional","affiliation":[{"name":"Department of Neurology, Piti\u00e9-Salp\u00eatri\u00e8re Hospital, APHP, Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vito","family":"Ricigliano","sequence":"additional","affiliation":[{"name":"UNIACT, NeuroSpin, Gif-sur-Yvette, France \rUMR 1129, INSERM, Universit\u00e9 Paris-Saclay, CEA, Gif-sur-Yvette, France Neurology Unit, GHNE-Paris Saclay Hospital, Orsay, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marie","family":"Senant","sequence":"additional","affiliation":[{"name":"CERBA Laboratory, Frepillon, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Caroline","family":"Papeix","sequence":"additional","affiliation":[{"name":"Department of Neurology, H\u00f4pital Fondation A. de Rothschild, Paris, France Universit\u00e9 Paris-Cit\u00e9, Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bruno","family":"Stankoff","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4987-1531","authenticated-orcid":false,"given":"Celine","family":"Louapre","sequence":"additional","affiliation":[{"name":"Department of Neurology, Piti\u00e9-Salp\u00eatri\u00e8re Hospital, APHP, Paris, France \rParis Brain Institute, ICM, CNRS, Inserm, Sorbonne Universit\u00e9, Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7699-0328","authenticated-orcid":false,"given":"Elisabeth","family":"Maillart","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5109-8533","authenticated-orcid":false,"given":"Andrea","family":"Lazzarotto","sequence":"additional","affiliation":[{"name":"Department of Neurology, Piti\u00e9-Salp\u00eatri\u00e8re Hospital, APHP, Paris, France"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"179","published-online":{"date-parts":[[2026,3,30]]},"reference":[{"key":"e_1_3_2_2_2","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2020.549842"},{"key":"e_1_3_2_3_2","doi-asserted-by":"publisher","DOI":"10.1074\/jbc.M113.501668"},{"key":"e_1_3_2_4_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa044397"},{"key":"e_1_3_2_5_2","doi-asserted-by":"publisher","DOI":"10.1056\/NEJMoa044396"},{"key":"e_1_3_2_6_2","doi-asserted-by":"publisher","DOI":"10.1212\/01.wnl.0000277457.17420.b5"},{"key":"e_1_3_2_7_2","doi-asserted-by":"publisher","DOI":"10.1177\/1352458512460604"},{"key":"e_1_3_2_8_2","first-page":"183","article-title":"Tumefactive demyelinating lesions associated with natalizumab-related rebound","volume":"354","author":"Debs R","year":"2015","unstructured":"Debs R, Rubin N, Perez C, et al. Tumefactive demyelinating lesions associated with natalizumab-related rebound. J Neurol Sci 2015; 354: 183\u2013186.","journal-title":"J Neurol Sci"},{"key":"e_1_3_2_9_2","first-page":"260","article-title":"Rebound disease activity and antibodies after natalizumab cessation","volume":"262","author":"Svenningsson A","year":"2013","unstructured":"Svenningsson A, Falk G, Zetterberg H, et al. Rebound disease activity and antibodies after natalizumab cessation. J Neuroimmunol 2013; 262: 260\u2013262.","journal-title":"J Neuroimmunol"},{"key":"e_1_3_2_10_2","doi-asserted-by":"publisher","DOI":"10.1177\/1352458512462920"},{"key":"e_1_3_2_11_2","doi-asserted-by":"publisher","DOI":"10.1177\/1352458511404271"},{"key":"e_1_3_2_12_2","doi-asserted-by":"publisher","DOI":"10.1177\/1352458510385508"},{"key":"e_1_3_2_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(17)30470-2"},{"key":"e_1_3_2_14_2","doi-asserted-by":"publisher","DOI":"10.1177\/1352458518815602"},{"key":"e_1_3_2_15_2","first-page":"61","article-title":"Prevalence and correlates of anti-natalizumab antibodies: a Swedish multiple sclerosis cohort study","volume":"17","author":"Holm\u00e9n C","year":"2011","unstructured":"Holm\u00e9n C, Olsson T, Jakobsson M, et al. Prevalence and correlates of anti-natalizumab antibodies: a Swedish multiple sclerosis cohort study. Mult Scler J 2011; 17: 61\u201368.","journal-title":"Mult Scler J"},{"key":"e_1_3_2_16_2","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2023.1242508"},{"key":"e_1_3_2_17_2","doi-asserted-by":"publisher","DOI":"10.1007\/s00415-013-6991-2"},{"key":"e_1_3_2_18_2","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2020.01951"},{"key":"e_1_3_2_19_2","doi-asserted-by":"publisher","DOI":"10.1186\/s12974-019-1593-2"},{"key":"e_1_3_2_20_2","doi-asserted-by":"publisher","DOI":"10.1001\/archneur.64.9.1331"}],"container-title":["Multiple Sclerosis Journal \u2013 Experimental, Translational and Clinical"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/20552173261438267","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/full-xml\/10.1177\/20552173261438267","content-type":"application\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.sagepub.com\/doi\/pdf\/10.1177\/20552173261438267","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T11:46:19Z","timestamp":1775043979000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.sagepub.com\/doi\/10.1177\/20552173261438267"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1]]},"references-count":19,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2026,1]]}},"alternative-id":["10.1177\/20552173261438267"],"URL":"https:\/\/doi.org\/10.1177\/20552173261438267","relation":{},"ISSN":["2055-2173","2055-2173"],"issn-type":[{"value":"2055-2173","type":"print"},{"value":"2055-2173","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1]]},"article-number":"20552173261438267"}}