Abstract Introduction Eosinophilic pneumonia (EP) refers to interstitial lung diseases characterized by pulmonary eosinophilic infiltration and elevated eosinophils in bronchoalveolar lavage (BAL) fluid with or without peripheral eosinophilia. Infliximab, an anti-TNF agent, has rarely been reported as a cause, typically acutely after starting the medication. We report a case of EP thought to be due to infliximab that occurred 6 years after starting therapy. Case Description A 27-year-old female presented with one week history of exertional dyspnea, night sweats, and right-sided pleuritic chest pain. Her medical history was significant for pan-ulcerative colitis in remission on infliximab (last infusion one month prior). She had been on infliximab for 6 years. She denied smoking, vaping, or recent travel. On presentation, her vitals were significant for hypoxemia with oxygen saturation of 79% on room air, heart rate of 152 and respiratory rate of 24 breaths/min. She was afebrile and normotensive. Physical exam was significant for right-sided crackles. Labs showed leukocytosis (WBC 54.1 × 10³) with 88% eosinophils, CRP 117 mg/L, and negative troponins. Chest radiograph showed bilateral peripheral-predominant lower-lobe opacities with trace effusions, and computed tomography (CT) pulmonary angiography demonstrated bilateral, peripheral ground-glass nodular opacities without pulmonary embolism (Image). She was admitted to the medical intensive care unit due to requiring high-flow nasal cannula, and was empirically started on ceftriaxone, azithromycin, and vancomycin. Broad infectious workup was negative, including respiratory viral PCR, blood cultures, Legionella antigen, and Strongyloides antibody. Autoimmune testing (ANA, ANCA, and anti-GBM) was negative, and serum IgE was elevated (794 IU/mL). Bronchoscopy was performed, and BAL was significant for 85% eosinophils, suggesting eosinophilic pneumonia. She was started on IV steroids followed by a short oral taper. Her oxygen requirements and peripheral eosinophil count rapidly improved, and she was discharged on hospital day 4. At six-week follow-up, she was asymptomatic and remained off infliximab. She had no peripheral eosinophilia, and her spirometry was normal. A repeat CT showed almost complete resolution of prior opacities. Discussion Both idiopathic and secondary forms of EP exist. This case is most consistent with delayed onset EP in the setting of infliximab use that occurred years after starting therapy. The diagnosis requires exclusion of infection, parasitic disease, neoplasm, and autoimmune disorders, as well as confirmation of eosinophilic inflammation on BAL. This case underscores the importance of considering EP in patients receiving biologics regardless of duration of therapy and the role of early recognition, drug cessation, and corticosteroids. This abstract is funded by: None
Zoubi et al. (Fri,) studied this question.