Abstract Introduction Acute respiratory failure in myasthenia gravis (MG) patients presents a unique diagnostic and therapeutic challenge. While MG increases the risk of coexisting autoimmune diseases, there is scarce literature on MG’s association with interstitial lung disease (ILD). We present a case of anti-MDA5 ILD in a MG patient. Case A 56-year-old female with a history of MG status post thymectomy presents with progressive dyspnea. One month earlier, she had been evaluated for flank pain, polyarthralgia, and rash; a computed tomography (CT) scan incidentally found patchy bibasilar reticular pulmonary opacities. Two weeks later, she developed acute dyspnea and was hospitalized for presumed community-acquired pneumonia. She was discharged with daily prednisone and supplemental oxygen. However, she re-presented to the ED with worsening dyspnea and was admitted to the intensive care unit for acute hypoxic respiratory failure requiring non-invasive ventilation. Despite empiric antibiotics, her respiratory status continued to decline. A transbronchial cryobiopsy performed had led to a pneumothorax requiring chest tube placement, followed by intubation for acute respiratory distress syndrome. Pathology showed variable interstitial fibrosis and Masson bodies pathognomonic for organizing pneumonia. High-dose corticosteroids were initiated for a presumed autoimmune ILD, but she continued to deteriorate despite maximal ventilatory support and was transferred to an extracorporeal membrane oxygenation (ECMO)-capable center. Autoimmune workup revealed positive anti-MDA5 antibodies, confirming a diagnosis of anti-MDA5 ILD. She was ultimately extubated on ECMO but was not a candidate for lung transplant and transitioned to comfort care and passed away. Discussion In MG patients with acute respiratory failure, autoimmune ILD should remain high on the differential alongside myasthenic crisis. Up to 22% of patients with MG may present with another autoimmune disease, and studies demonstrate a 21-fold higher likelihood of developing polymyositis or dermatomyositis. Clinicians should consider serial maximal inspiratory force and forced vital capacity monitoring, myositis-antibody testing, and high-resolution CT chest imaging in such patients. Anti-MDA5 ILD is a rare, aggressive condition associated with clinically amyopathic dermatomyositis that is often refractory to corticosteroids and necessitates additional immunosuppression and at times, ECMO or lung transplantation. Conclusion This case highlights the importance of recognizing autoimmune ILD in MG patients with unexplained respiratory failure. Although rare, anti-MDA5 ILD portends a high mortality risk, thus early suspicion and comprehensive evaluation may enable timely escalation of care and improve outcomes. Further research is needed to study the relationship between MG and ILD and if MG confers a true increased risk for ILD This abstract is funded by: None
Bui et al. (Fri,) studied this question.