{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,21]],"date-time":"2025-11-21T06:20:47Z","timestamp":1763706047581,"version":"3.37.3"},"reference-count":9,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2021,4,2]],"date-time":"2021-04-02T00:00:00Z","timestamp":1617321600000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2021,4,2]],"date-time":"2021-04-02T00:00:00Z","timestamp":1617321600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Rheumatol"],"published-print":{"date-parts":[[2021,12]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec>\n                <jats:title>Background<\/jats:title>\n                <jats:p>Patients with idiopathic inflammatory myopathy and autoantibodies directed against melanoma differentiation-associated protein 5 (MDA5) characteristically have interstitial lung disease, severe cutaneous involvement, arthritis, and relatively mild myositis. Cardiac involvement in idiopathic inflammatory myopathy can occur and has been associated with anti-signal recognition particle and anti-polymyositis-scleroderma autoantibodies, but not with anti-MDA5 autoantibodies.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Case presentation<\/jats:title>\n                <jats:p>A 14-year-old male presented with weakness, second-degree heart block, arthritis, and hematologic cytopenias. Imaging and biopsies confirmed the diagnosis of juvenile idiopathic inflammatory myopathy, and he had high titer anti-MDA5 autoantibodies. There were no cutaneous or pulmonary abnormalities. While on prednisone and methotrexate, the patient\u2019s heart block improved from second- to first-degree and the cytopenias resolved. Persistent myositis prompted the addition of intravenous immunoglobulin. Seven months into the disease course, the arthritis and myositis are in remission and the patient is no longer taking corticosteroids.<\/jats:p>\n              <\/jats:sec><jats:sec>\n                <jats:title>Conclusions<\/jats:title>\n                <jats:p>We report a novel case of a patient with juvenile idiopathic myositis who lacked the typical cutaneous and pulmonary findings associated with anti-MDA5 positivity, but who had cardiac conduction defects. This report broadens the clinical spectrum of anti-MDA5-associated inflammatory myopathy.<\/jats:p>\n              <\/jats:sec>","DOI":"10.1186\/s41927-021-00180-9","type":"journal-article","created":{"date-parts":[[2021,4,1]],"date-time":"2021-04-01T23:03:47Z","timestamp":1617318227000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Anti-MDA5 juvenile idiopathic inflammatory myopathy with second-degree heart block but no skin or lung involvement: a case report"],"prefix":"10.1186","volume":"5","author":[{"given":"Meghan E.","family":"Ryan","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Daniel","family":"Cortez","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kelly R.","family":"Dietz","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Peter","family":"Karachunski","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3127-3856","authenticated-orcid":false,"given":"Bryce A.","family":"Binstadt","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2021,4,2]]},"reference":[{"issue":"9","key":"180_CR1","doi-asserted-by":"publisher","first-page":"1726","DOI":"10.1093\/rheumatology\/keq153","volume":"49","author":"K Hoshino","year":"2010","unstructured":"Hoshino K, Muro Y, Sugiura K, Tomita Y, Nakashima R, Mimori T. Anti-MDA5 and anti-TIF1-gamma antibodies have clinical significance for patients with dermatomyositis. Rheumatology (Oxford). 2010;49(9):1726\u201333.","journal-title":"Rheumatology (Oxford)"},{"issue":"4","key":"180_CR2","doi-asserted-by":"publisher","first-page":"R138","DOI":"10.1186\/ar4600","volume":"16","author":"SL Tansley","year":"2014","unstructured":"Tansley SL, Betteridge ZE, Gunawardena H, Jacques TS, Owens CM, Pilkington C, et al. Anti-MDA5 autoantibodies in juvenile dermatomyositis identify a distinct clinical phenotype: a prospective cohort study. Arthritis Res Ther. 2014;16(4):R138.","journal-title":"Arthritis Res Ther"},{"issue":"8","key":"180_CR3","doi-asserted-by":"publisher","first-page":"1927","DOI":"10.1093\/rheumatology\/kez525","volume":"59","author":"I Melki","year":"2020","unstructured":"Melki I, Devilliers H, Gitiaux C, Bondet V, Duffy D, Charuel J-L, et al. Anti-MDA5 juvenile idiopathic inflammatory myopathy: a specific subgroup defined by differentially enhanced interferon-\u03b1 signalling. Rheumatology (Oxford). 2020;59(8):1927\u201337.","journal-title":"Rheumatology (Oxford)"},{"issue":"1","key":"180_CR4","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1111\/joim.12451","volume":"280","author":"Z Betteridge","year":"2016","unstructured":"Betteridge Z, McHugh N. Myositis-specific autoantibodies: an important tool to support diagnosis of myositis. J Intern Med. 2016;280(1):8\u201323.","journal-title":"J Intern Med"},{"issue":"1","key":"180_CR5","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1007\/s12519-019-00313-8","volume":"16","author":"J-Q Wu","year":"2020","unstructured":"Wu J-Q, Lu M-P, Reed AM. Juvenile dermatomyositis: advances in clinical presentation, myositis-specific antibodies and treatment. World J Pediatr. 2020;16(1):31\u201343.","journal-title":"World J Pediatr"},{"issue":"1","key":"180_CR6","doi-asserted-by":"publisher","first-page":"63","DOI":"10.1002\/acr.20015","volume":"62","author":"A Ravelli","year":"2010","unstructured":"Ravelli A, Trail L, Ferrari C, Ruperto N, Pistorio A, Pilkington C, et al. Long-term outcome and prognostic factors of juvenile dermatomyositis: a multinational, multicenter study of 490 patients. Arthritis Care Res (Hoboken). 2010;62(1):63\u201372.","journal-title":"Arthritis Care Res (Hoboken)"},{"key":"180_CR7","doi-asserted-by":"publisher","first-page":"16","DOI":"10.1016\/j.jpeds.2017.12.053","volume":"195","author":"LM Pachman","year":"2018","unstructured":"Pachman LM, Khojah AM. Advances in juvenile dermatomyositis: myositis specific antibodies aid in understanding disease heterogeneity. J Pediatr. 2018;195:16\u201327.","journal-title":"J Pediatr"},{"issue":"6","key":"180_CR8","doi-asserted-by":"publisher","first-page":"837","DOI":"10.2169\/internalmedicine.1516-18","volume":"58","author":"N Sakamoto","year":"2019","unstructured":"Sakamoto N, Ishimoto H, Nakashima S, Yura H, Miyamura T, Okuno D, et al. Clinical features of anti-MDA5 antibody-positive rapidly progressive interstitial lung disease without signs of dermatomyositis. Intern Med. 2019;58(6):837\u201341.","journal-title":"Intern Med"},{"issue":"11","key":"180_CR9","doi-asserted-by":"publisher","first-page":"2185","DOI":"10.1001\/archinte.1984.04400020097015","volume":"144","author":"R Stern","year":"1984","unstructured":"Stern R, Godbold JH, Chess Q, Kagen LJ. ECG abnormalities in polymyositis. Arch Intern Med. 1984;144(11):2185\u20139.","journal-title":"Arch Intern Med"}],"container-title":["BMC Rheumatology"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1186\/s41927-021-00180-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/article\/10.1186\/s41927-021-00180-9\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"http:\/\/link.springer.com\/content\/pdf\/10.1186\/s41927-021-00180-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,4,1]],"date-time":"2021-04-01T23:12:50Z","timestamp":1617318770000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmcrheumatol.biomedcentral.com\/articles\/10.1186\/s41927-021-00180-9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,4,2]]},"references-count":9,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2021,12]]}},"alternative-id":["180"],"URL":"https:\/\/doi.org\/10.1186\/s41927-021-00180-9","relation":{},"ISSN":["2520-1026"],"issn-type":[{"type":"electronic","value":"2520-1026"}],"subject":[],"published":{"date-parts":[[2021,4,2]]},"assertion":[{"value":"16 November 2020","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"31 January 2021","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"2 April 2021","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"Not applicable.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Written informed consent was obtained from the patient\u2019s legal guardian(s) for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"Authors declare no conflicts of interest.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"8"}}