(1196) Secondary Organizing Pneumonia due to COVID-19 in an Immunocompromised Patient With Polymyositis

Introduction: Organizing pneumonia secondary to COVID-19 usually has a subacute presentation with a prolonged clinical course. Risk factors leading to progression remain uncertain. We present a 56-year-old male who developed organizing pneumonia due to COVID-19 on chronic immunosuppression with rituximab therapy (anti CD20) with a rapid deterioration of clinical course and poor outcome.

Description: A 56-year-old male presented to the ED with acute onset of dyspnea. Medical history was significant for refractory polymyositis on chronic rituximab therapy. He had received COVID-19 (mRNA) vaccination. Initial testing revealed he was SARS-CoV-2 positive and was managed as an outpatient with Bebtelovimab infusion without significant clinical improvement. On hospital admission, CT Chest showed bilateral lower lobe atelectasis. He was treated empirically for pneumonia along with dexamethasone. Remdesivir was not given due to patient preference.

Two weeks later, he was readmitted for persistent fevers. Infectious work up for typical and atypical respiratory pathogens were negative. CT Chest showed interval worsening with bilateral peripheral sub pleural ground glass opacities. Bronchoalveolar lavage showed mixed inflammatory infiltrates with lung biopsy showing foamy macrophages and focal fibrosis suggestive of organizing pneumonia. He was started on prednisone 1 mg/kg and then escalated to intravenous methylprednisolone along with azathioprine for worsening respiratory failure. Subsequently he was put on mechanical ventilation and started on venovenous Extracorporeal Membrane Oxygenation along with lung rest strategy. Despite continued treatment for two weeks, he succumbed to his illness.

Discussion: Organizing pneumonia in COVID –19 usually has a subacute to chronic presentation. Rapid progression leading to acute fibrinous organizing pneumonia with poor prognosis has been described. This case highlights the fact that organizing pneumonia needs to be considered in the differential of COVID-19 pneumonia with chronic immunosuppression. We postulate that immunosuppression with rituximab in addition to COVID-19 pneumonia may have led to rapid progression to fibrinous stage. Corticosteroids remain the cornerstone of treatment. The benefit of anti-viral treatment remains to be determined.