A RARE CASE OF INTERSTITIAL LUNG DISEASE IN IDIOPATHIC INFLAMMATORY MYOSITIS ASSOCIATED WITH ANTI-MDA5

TOPIC: Pulmonary Manifestations of Systemic Disease TYPE: Medical Student/Resident Case Reports INTRODUCTION: Anti-MDA5 (anti-melanoma differentiation-associated gene-5) associated dermatomyositis (DM) is a rare presentation idiopathic inflammatory myositis, often presenting with treatment refractory rapidly progressing interstitial lung disease (ILD). Diagnosis difficult as patients can present without symptoms or biochemical evidence DM. We report adult case anti-MDA5 ILD only pulmonary manifestations. CASE PRESENTATION: 74-year-old female past medical history atrial fibrillation status post pacemaker, reactive airway disease, and heart failure preserved ejection fraction, was referred to clinic for abnormal CT scan dyspnea that began 4 months prior while living in India. Initial chest significant bi-apical consolidations bronchiectasis. Bronchoscopy lavage positive Aspergillus galactomannan, she treated isavuconazole, prednisone, Septra (for pneumocystis prophylaxis). Chest weeks later showed improvement consolidations. 3 later, recurred. She re-started on prednisone 20 mg daily, resolved. subsequently relocated the USA. had serial negative COVID tests. function test restrictive ventilatory defect decreased diffusion capacity. Follow-up revealed scarring, multifocal airspace consolidation. ESR 44 (elevated) CRP 11.2 (elevated). IGE, aldolase, CK, hypersensitivity pneumonitis antibody panel, antibody, nuclear RF, anti-CCP were negative. Extended myositis panel high titer RNA polymerase antibodies; confirmed different extended assay. rheumatologist who recommended aggressive immune modulating tacrolimus cyclophosphamide. After discussion, opted mycophenolate mofetil prednisone. DISCUSSION: DM progressive poor prognosis. In small prospective study, triple therapy regimen consisting dose glucocorticoid, Tacrolimus, intravenous Cyclophosphamide 6-month survival benefit compared step-up approach (which entailed starting glucocorticoids combining immunomodulators). Plasmapheresis has been used have failed combination immunomodulators multiple studies. CONCLUSIONS: should be considered new ILD, since it Intense drug suppression from beginning. transplant if become immunosuppression. REFERENCE #1: Gupta R, Kumar S, Gow P, Hsien-Cheng Chang L, Yen L. Anti-MDA5-associated dermatomyositis. Intern Med J. 2020 Apr;50(4):484-487. doi: 10.1111/imj.14789. PMID: 32270621. #2: Fiorentino D, Chung Zwerner J, Rosen A, Casciola-Rosen The mucocutaneous systemic phenotype antibodies MDA5 (CADM-140): retrospective study. J Am Acad Dermatol. 2011 Jul;65(1):25-34. 10.1016/j.jaad.2010.09.016. Epub Apr 29. 21531040; PMCID: PMC3167687. #3: Hall JC, Samedy LA, Werner Owoyemi K, Danoff SK, Christopher-Stine Anti-melanoma protein 5-associated dermatomyositis: expanding clinical spectrum. Arthritis Care Res (Hoboken). 2013 Aug;65(8):1307-15. 10.1002/acr.21992. 23436757; PMC3689861. DISCLOSURES: No relevant relationships by Peter Huh, source=Web Response Sudhir Rajan, Eduardo Solbes,