{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T05:41:38Z","timestamp":1760334098456,"version":"build-2065373602"},"reference-count":20,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T00:00:00Z","timestamp":1760313600000},"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. Immunol."],"abstract":"<jats:p>Double Seropositive Myasthenia Gravis (DSP-MG), a rare variant of Myasthenia Gravis (MG), is defined by the simultaneous presence of both anti-acetylcholine receptor (AChR) antibodies and anti-muscle-specific tyrosine kinase (MuSK) antibodies in the serum of affected individuals. Currently, no standardized therapeutic protocol exists for DSP-MG due to its scarcity and clinical heterogeneity. Herein, we report a case of a 68-year-old female patient with DSP-MG who showed significant clinical improvement during an acute exacerbation after treatment with the FcRn antagonist efgartigimod, following the failure of conventional therapy. After a cycle of efgartigimod treatment, complete resolution of myasthenic symptoms was observed. During the 6-month follow-up, with sustained clinical remission and attainment of Minimal Manifestation Status (MMS). This case represents the first documented use of efgartigimod in a DSP-MG patient, providing preliminary clinical evidence for its potential efficacy in this rare and poorly understood subtype. Our findings contribute to the limited literature on DSP-MG and suggest that FcRn inhibition may offer a viable treatment option where conventional therapies fail. Efgartigimod may represent a potential therapeutic agent for DSP-MG.<\/jats:p>","DOI":"10.3389\/fimmu.2025.1610738","type":"journal-article","created":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T05:26:53Z","timestamp":1760333213000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Case Report: Efgartigimod demonstrates significant clinical efficacy in double seropositive myasthenia gravis: a case report of a rare variant and analysis of pathomechanisms"],"prefix":"10.3389","volume":"16","author":[{"given":"Xiaohui","family":"Huang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yue","family":"Wan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yu","family":"Chen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Keqi","family":"Lei","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,10,13]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1002\/mus.27177","article-title":"Subunit specificity of the acetylcholine receptor antibodies in double seropositive myasthenia gravis","volume":"63","author":"Zouvelou","year":"2021","journal-title":"Muscle Nerve"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1007\/s10072-021-05042-3","article-title":"AChRAb and MuSKAb double-seropositive myasthenia gravis: a distinct subtype","volume":"42","author":"Zhang","year":"2021","journal-title":"Neurol Sci"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1016\/j.jns.2024.123047","article-title":"Acetylcholinesterase inhibitors are ineffective in MuSK-antibody positive myasthenia gravis: Results of a study on 202 patients","volume":"461","author":"Ricciardi","year":"2024","journal-title":"J Neurol Sci"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2020.00981","article-title":"From traditional to targeted immunotherapy in myasthenia gravis: prospects for research","volume":"11","author":"Mantegazza","year":"2020","journal-title":"Front Neurol"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1016\/j.jns.2020.116690","article-title":"Differential response to rituximab in anti-AChR and anti-MuSK positive myasthenia gravis patients: a single-center retrospective study","volume":"411","author":"Litchman","year":"2020","journal-title":"J Neurol Sci"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1007\/s40265-022-01726-y","article-title":"Pharmacotherapy of generalized myasthenia gravis with special emphasis on newer biologicals","volume":"82","author":"Menon","year":"2022","journal-title":"Drugs"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1016\/S1474-4422(21)00159-9","article-title":"Safety, efficacy, and tolerability of efgartigimod in patients with generalised myasthenia gravis (ADAPT): a multicentre, randomised, placebo-controlled, phase 3 trial","volume":"20","author":"Howard","year":"2021","journal-title":"Lancet Neurol"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2024.1497398","article-title":"Case report: efgartigimod is a novel therapeutic option for ocular myasthenia gravis: a report of 2 cases","volume":"15","author":"Ma","year":"2024","journal-title":"Front Immunol"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.3389\/fimmu.2024.1401972","article-title":"Case report: Rapid clinical improvement in acute exacerbation of MuSK-MG with efgartigimod","volume":"15","author":"Zhu","year":"2024","journal-title":"Front Immunol"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2024.1486659","article-title":"Efgartigimod treatment in patients with anti-MuSK-positive myasthenia gravis in exacerbation","volume":"15","author":"Shi","year":"2024","journal-title":"Front Neurol"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.2169\/internalmedicine.3726-24","article-title":"Efgartigimod successfully ameliorated acute exacerbation of myasthenia gravis with anti-muscle-specific kinase antibodies","volume":"64","author":"Tanaka","year":"2024","journal-title":"Intern Med"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1111\/nyas.13522","article-title":"Myasthenia gravis: the role of complement at the neuromuscular junction","volume":"1412","author":"Howard","year":"2018","journal-title":"Ann N Y Acad Sci"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1101\/cshperspect.a009167","article-title":"The role of MuSK in synapse formation and neuromuscular disease","volume":"5","author":"Burden","year":"2013","journal-title":"Cold Spring Harb Perspect Biol"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaut.2016.11.005","article-title":"IgG4 autoantibodies against muscle-specific kinase undergo fab-arm exchange in myasthenia gravis patients","volume":"77","author":"Koneczny","year":"2017","journal-title":"J Autoimmun"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1016\/j.jneuroim.2015.12.016","article-title":"Longitudinal epitope mapping in MuSK myasthenia gravis: implications for disease severity","volume":"291","author":"Huijbers","year":"2016","journal-title":"J Neuroimmunol"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1111\/j.1749-6632.1998.tb10948.x","article-title":"Epitope spreading in experimental autoimmune myasthenia gravis","volume":"841","author":"Agius","year":"1998","journal-title":"Ann N Y Acad Sci"},{"key":"B17","doi-asserted-by":"publisher","first-page":"e16306","DOI":"10.1111\/ene.16306","article-title":"Overcoming therapeutic challenges: successful management of a supposedly triple seronegative, refractory generalized myasthenia gravis patient with efgartigimod","volume":"31","author":"Sorrenti","year":"2024","journal-title":"Eur J Neurol"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1177\/17562864231213240","article-title":"Guideline for the management of myasthenic syndromes","volume":"16","author":"Wiendl","year":"2023","journal-title":"Ther Adv Neurol Disord"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.3389\/fneur.2021.662856","article-title":"Therapeutic plasma exchange in myasthenia gravis: a systematic literature review and meta-analysis of comparative evidence","volume":"12","author":"Ipe","year":"2021","journal-title":"Front Neurol"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1007\/s00415-024-12588-7","article-title":"A real-life experience with eculizumab and efgartigimod in generalized myasthenia gravis patients","volume":"271","author":"Pane","year":"2024","journal-title":"J Neurol"}],"container-title":["Frontiers in Immunology"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1610738\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T05:26:55Z","timestamp":1760333215000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fimmu.2025.1610738\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,13]]},"references-count":20,"alternative-id":["10.3389\/fimmu.2025.1610738"],"URL":"https:\/\/doi.org\/10.3389\/fimmu.2025.1610738","relation":{},"ISSN":["1664-3224"],"issn-type":[{"value":"1664-3224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,13]]},"article-number":"1610738"}}