Rapidly Progressing Secondary Organizing Pneumonia Due to Underlying Immunosuppression With Rituximab in SARS-CoV-2 Patients

Secondary organizing pneumonia (SOP) as a sequela to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) usually has a prolonged benign course with a good response to corticosteroids. We present a case series of three patients who developed rapid progression to organizing pneumonia, after initial presentation with SARS-CoV-2. Imaging revealed rapid interval progression of bilateral subpleural ground glass opacities, and lung biopsy showed dense fibroblastic plugs within the alveoli. Two patients were steroid-responsive, and one patient succumbed to his illness despite maximal therapy. We postulate that B-cell depletion and immunosuppression may cause rapid progression to SOP, as all three patients were immunosuppressed and on chronic rituximab therapy.