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A1543 - Refractory Rapidly Progressive Interstitial Lung Disease in Anti-Melanoma Differentiation Antibody with Clinically Amyopathic Dermatomyositis
Author Block: Z. Lundstrom1, K. Pennington1, C. M. Batzlaff2; 1Mayo Clinic, Rochester, MN, United States, 2Pulmonary and Critical Care Medicine, Mayo Clinic, Rochester, MN, United States.
Rapidly progressive-interstitial lung disease (RP-ILD) associated with dermatomyositis develops acutely and represent a diagnostic and therapeutic challenge in Pulmonary/Critical Care. We present a fatal case of RP-ILD in a patient with clinically-amyopathic dermatomyositis (CADM) associated with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody. A previously healthy 57-year-old woman presented to the emergency department with a two month history of dyspnea on exertion, arthralgias, nightly fever, oral aphthous ulcers, Raynaud phenomenon, and skin changes involving her hands, chest, and forehead. On physical examination, she had several cutaneous findings: Gottron's papules, mechanic hands, shawl sign, and an erythematous facial rash sparing the naso-labial folds. She required 2 liters per minute nasal cannula oxygen at rest. Her creatine kinase was normal with a mildly elevated aldolase. ANA and extractable nuclear antigen testing, including Anti-Jo-1, were negative. A myositis-specific autoantibody panel, post-humously, returned positive for anti-MDA5 antibody. Skin biopsy of her chest revealed vacuolar interface dermatitis consistent with dermatomyositis. CT chest was notable for interstitial lung disease in a NSIP pattern with traction bronchiectasis and bibasilar fibrosis. Secondary to progressive hypoxemia, repeat CT chest within 1 week of initial presentation revealed progressive diffuse ground glass opacities. Given her high fevers and rapidly progressive CT changes, bronchoscopy with BAL was completed. Samples were negative for any infectious etiology. She was initiated on high dose pulse steroids in conjunction with cyclophosphamide. Secondary to progressive hypoxemia, she was ultimately intubated and mechanically ventilated with lung protective ventilation. Despite five days of high dose steroids and cyclophosphamide initiation, she developed refractory hypoxemia requiring paralysis and prone positioning. Nitric oxide and alprostadil were trialed as her oxygenation continued to decline. She was subsequently initiated on a five day course of IVIG to attempt to gain control of her primary disease process. Lung transplantation was not an option secondary to poor control of her underlying disease. ECMO was considered but was not pursued because of a lack of viable exit strategy. After nearly 20 days of mechanical ventilation, comfort care measures were initiated after discussion with the family. Shortly after withdrawal of support, she expired— just 25 days initial presentation. Anti-MDA5 antibody in dermatomyositis is associated with 26.85-fold higher risk of RP-ILD. Patients with this antibody should be treated early and aggressively with immunosuppressants. However, as in this case, delay in presentation and delay in antibody identification are barriers to early intervention.