LATE DIAGNOSIS OF ANTI-MDA5 ANTIBODY-POSITIVE RAPIDLY PROGRESSIVE INTERSTITIAL LUNG DISEASE WITH CUTANEOUS MANIFESTATIONS

Abstract

SESSION TITLE: Medical Student/Resident Lung Pathology SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody is associated with rapidly progressive interstitial lung disease (RP-ILD). This can be seen in patients with clinically amyopathic dermatomyositis or more typical dermatomyositis. Not only is MDA5-positive RP-ILD a rare cause of ILD, but the ILD often results in significant morbidity and mortality. Although there are several proposed treatment regimens, patients often succumb to the illness despite initiation of therapy. As such, early diagnosis and treatment in these patients is of paramount importance. CASE PRESENTATION: Herein we report a case of 37-year-old male diagnosed with anti-MDA5-associated RP-ILD late in his clinical course. He presented in October 2019. He initially presented with marked unintentional weight loss, preceding episodes of antimicrobial-refractory pneumonia, and an upper thigh abscess prior to his transfer to our hospital. He had a complicated hospital course with profound multi-organ system failure. Given an unclear underlying diagnosis, empiric antimicrobials and corticosteroids were started and intensified, without improvement. Furthermore, his secondary acute respiratory distress syndrome did not respond to standard evidence-based strategies. In the setting of chest imaging suggestive of underlying ILD with profound pneumomediastium and concomitant Gottron papules, rheumatologic work-up revealed a unifying diagnosis very late in his hospital course. Despite mechanical ventilation, venovenous extracorporeal membrane oxygenation (VV-ECMO), high-dose steroids, intravenous immunoglobulin, and tacrolimus, the patient had little clinical response to his disease which ultimately proved fatal. DISCUSSION: To the best of our knowledge, this is one of the first cases where VV-ECMO was used to treat anti-MDA5 positive RP-ILD. Unfortunately, this case demonstrates the futility of supporting patients with anti-MDA5 positive RP-ILD with VV-ECMO, particularly when that support is initiated late in their clinical course. His hospital and pre-hospital course highlight the barriers of a healthcare system that ultimately could not save him. Moreover, this case illustrates the importance of early diagnosis and expedited trials of therapy. In the future, early diagnosis of anti-MDA5 positive RP-ILD may support the utility of VV-ECMO as a bridge to lung transplant. CONCLUSIONS: In a case such as this one, where the diagnosis eludes while irreversible lung disease progresses, ECMO is a therapeutic modality best avoided. We would further recommend, should ECMO be utilized in such cases, where the diagnosis has yet to be made, it is important that all parties involved are clear on the overall treatment plan to include when extracorporeal support will be withdrawn. Reference #1: Gonzalez-Moreno et al. Rapidly progressive interstitial lung disease due to anti-MDA5 antibodies without skin involvement: a case report and literature review. Rheumatology International 2018. 38:1293-1296. Reference #2: LeClair et al. Successful lung transplantation in a case of rapidly progressive interstitial lung disease associated with antimelanoma differentiation-associated gene 5 antibodies. Journal of Rheumatology 2018. 45:581-583. Reference #3: So et al. Rituximab for refractory rapidly progressive interstitial lung disease related to anti-MDA5 antibody-positive amyopathic dermatomyositis. Clinical Rheumatology 2018. 37:1983-1989. DISCLOSURES: No relevant relationships by Erika Anderson, source=Web Response No relevant relationships by Cyrus Askin, source=Web Response No relevant relationships by Carl Kay, source=Web Response No relevant relationships by Whittney Warren, source=Web Response