{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T17:41:05Z","timestamp":1792172465096,"version":"4.4.0"},"reference-count":28,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T00:00:00Z","timestamp":1731974400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Neurol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>The prevalence of patients positive for muscle-specific kinase antibody (hereafter, MuSK-Ab) accounts for 5\u20138% of all myasthenia gravis (MG) cases. Currently, efgartigimod has shown good therapeutic effects in MUSK-Ab-positive MG patients in a phase III clinical trial. However, phase III clinical trials tend to exclude MG patients in exacerbation, and there are only few real-world studies on the efficacy of efgartigimod in MuSK-Ab-positive myasthenic crisis (MC) patients. This retrospective, real-world study aimed to explore the efficacy of efgartigimod in MuSK-Ab-positive MG with exacerbation.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>We reviewed the clinical data of four MuSK-Ab-positive patients with exacerbation of MG who received efgartigimod at the First Affiliated Hospital of Sun Yat-sen University, including two patients with MC. All patients were admitted between September 2023 and May 2024. Most patients are simultaneously undergoing rituximab treatment.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Each patient completed one cycle of efgartigimod. After the first administration, four patients showed a clinically meaningful decrease in the Myasthenia Gravis Activities of Daily Living (MG-ADL) score (a reduction of more than 4 points compared to baseline), and all patients showed a decrease in IgG levels after one cycle of efgartigimod. Regarding safety, none of the patients experienced any obvious adverse effects. At the final follow-up, all patients achieved the minimal symptom expression status (an MG-ADL score of 0 or 1) following the first administration of efgartigimod for 8.75\u2009\u00b1\u20095.56\u2009weeks. This article presents a case involving a patient who exhibited prompt alleviation of symptoms following the administration of a high dose of efgartigimod (20\u2009mg\/kg, given on days 1 and 5), without the use of any other fast-acting treatment.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>This retrospective real-world study demonstrates the effectiveness and safety of efgartigimod in these four MuSK-Ab-positive, female Asian patients with exacerbation of MG, as well as in patients experiencing MC. It is important to note that efgartigimod should not be viewed as a substitute for foundational immunotherapy; rather, it is intended as a rescue treatment during exacerbations and as an adjunctive therapy in the context of long-term immunotherapy. This non-invasive approach has the potential to become another treatment option for MuSK-Ab-positive MG patients.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fneur.2024.1486659","type":"journal-article","created":{"date-parts":[[2024,11,19]],"date-time":"2024-11-19T06:18:19Z","timestamp":1731997099000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":16,"title":["Efgartigimod treatment in patients with anti-MuSK-positive myasthenia gravis in exacerbation"],"prefix":"10.3389","volume":"15","author":[{"given":"Fangyi","family":"Shi","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiaxin","family":"Chen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Li","family":"Feng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rong","family":"Lai","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongyan","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xunsha","family":"Sun","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cunzhou","family":"Shen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiezhen","family":"Feng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huiyu","family":"Feng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haiyan","family":"Wang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2024,11,19]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1002\/mus.27832","article-title":"Myasthenic 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