Abstract
Organizing pneumonia (OP) is a pulmonary inflammatory disorder involving the alveolar airspaces and ducts and resulting in interstitial lung disease. It is usually corticosteroid responsive. There have been reports of corticosteroid-resistant and refractory cases of organizing pneumonia (OP) requiring alternative treatment options, including immunosuppressants and cytotoxic agents. There are only a handful of cases of organizing pneumonia (OP) treated successfully with intravenous immunoglobulins (IVIg). We describe the novel case of a patient with a history of seronegative rheumatoid arthritis presenting with fever, increasing dyspnea, and diffuse opacities on chest imaging. Bronchoscopy revealed positive SARS-CoV-2 antigen, and she was treated with steroids. Due to recurrence of symptoms and worsening hypoxemia while on prolonged glucocorticoid taper, OP was confirmed on lung biopsy. The patient was placed on mycophenolate and glucocorticosteroids, but clinical and radiologic remission was not achieved. She was found to have immunoglobulin (IgG) deficiency and IVIg treatment was initiated which induced a successful clinical and radiologic response. This novel case highlights the need to consider IgG immune deficiency state when managing steroid- and immunosuppressant-resistant SARS-CoV-2-associated OP.