A case of rapidly progressive myositis-associated interstitial lung disease requiring extracorporeal membrane oxygenation: have you checked anti-mda-5 antibody?

SESSION TITLE: Pulmonary Potpourri: Rarest of the Rare SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/10/2023 09:40 am - 10:25 am INTRODUCTION: Rapidly progressive interstitial lung disease (RP-ILD) associated with idiopathic inflammatory myopathies, including dermatomyositis (DM), polymyositis (PM) and clinically amyopathic dermatomyositis (CADM), can prove fatal if not recognized and treated promptly. 1 Various myositis-specific autoantibodies (MSAs) have been recognized with anti-MDA-5 being associated with often fatal RP-ILD. 2 We report a case of sudden onset anti-MDA-5 antibody associated RP-ILD requiring veno-venous extracorporeal membrane oxygenation (VV-ECMO) despite upfront combined immunosuppression with pulse dose steroids and cyclophosphamide. CASE PRESENTATION: A 49-year-old female with history of hypertension presented with new onset acute hypoxemic respiratory failure requiring high flow nasal cannula. Respiratory failure was preceded by shortness of breath, progressive severe proximal muscle weakness, scaly rash involving extensor body surfaces, high grade fevers and weight loss. Initial infectious work up was negative. Computed Tomography (CT) of chest showed diffuse airspace consolidative opacities; organizing pneumonia pattern. Autoimmune screen was sent and she was started on corticosteroids with broad spectrum antibiotics. Initial work up including antinuclear antibody (ANA), complements C3/C4, Rheumatoid Factor (RF), anti-double stranded DNA, anti-Ro, anti-La, anti-Jo, anti-SCL-70, anti-cyclic citrullinated peptide (CCP), anti-glomerular basement membrane antibody (GBM), anti-myeloperoxidase, anti-proteinase3 was negative. Persistent hypoxemic respiratory failure required intubation and mechanical ventilation. Repeat CT chest showed worsening of diffuse ground glass opacites and lower lobe consolidations, nonspecific interstitial pneumonia (NSIP) pattern. Bronchoscopy with bronchoalveolar lavage (BAL) did not reveal diffuse alveolar hemorrhage and showed a neutrophil predominance on BAL cellular fluid analysis. With high suspicion for myositis associated rapidly progressive interstitial lung disease, anti-MDA-5 antibody was checked along with a full myositis-specific autoantibody panel. She was started on pulse dose corticosteroids and after multidisciplinary discussion with rheumatology, cyclophosphamide was added. Anti-MDA-5 antibody was elevated (90 U/ml) along with serum aldolase and ferritin. Skin biopsy confirmed dermatomyositis. With persistent refractory hypoxemic respiratory failure and no improvement, decision was made to start her on VV-ECMO as a bridge to recovery. Unfortunately, she continues to be on ECMO support with hospital course complicated by septic shock, pneumomediastinum and hemorrhagic stroke after one month of hospitalization with minimal recovery. Family is leaning towards comfort care with goals of care discussion. DISCUSSION: Anti-MDA-5 antibody associated CADM/or DM presents with unique features of mucocutaneous ulcerations, involving elbows, palmar papules and alopecia. It corresponds to one of the myositis associated ILD, different from antisynthetase syndrome. 1,2 Recognition of this variant is important due to its correlation with RP-ILD, often refractory to combined immunosuppression with fatal outcomes. 2 ECMO can be considered as a bridge to recovery or lung transplant in refractory cases but is not therapeutic and comes with its own complications. 3 CONCLUSIONS: Early clinical recognition of myositis-associated ILD requires clinician to remain vigilant of various MSAs and their unique phenotypic presentations. A high index of suspicion is required for a timely diagnosis of anti-MDA-5 antibody associated RP-ILD with upfront combined immunosuppression and ECMO consideration in refractory cases. REFERENCE #1: Hallowell RW, Danoff SK. Interstitial lung disease associated with the idiopathic inflammatory myopathies and the antisynthetase syndrome. Curr Opin Rheumatol. 2014;26(6):684-689. doi:10.1097/BOR.0000000000000104 REFERENCE #2: McPherson M, Economidou S, Liampas A, Zis P, Parperis K. Management of MDA-5 antibody positive clinically amyopathic dermatomyositis associated interstitial lung disease: A systematic review. Semin Arthritis Rheum. 2022;53:151959. doi:10.1016/j.semarthrit.2022.151959 REFERENCE #3: Rubin J, Black KE, Hallowell RW, et al. Veno-Venous Extracorporeal Membrane Oxygenation for Myositis-Associated Rapidly Progressive Interstitial Lung Disease. Chest. 2021;160(6):2163-2167. doi:10.1016/j.chest.2021.06.075 DISCLOSURES: No relevant relationships by Maria Azhar No relevant relationships by Isabel Mira-Avendano No relevant relationships by Khalid Mohamed Ahmed No relevant relationships by Bilal Zafar