C32-16 Pulmonary Renal Syndrome in a Patient With Recently Treated Eosinophilic Pneumonia

Introduction Both eosinophilic pneumonia and pulmonary renal syndrome are rare, severe diseases with high morbidity and mortality. Eosinophilic pneumonia is characterized by marked infiltration of eosinophils in alveolar spaces and bronchial walls and significant eosinophilia on bronchoalveolar lavage (BAL) samples. Pulmonary renal syndrome is characterized by diffuse alveolar hemorrhage and glomerulonephritis, most commonly caused by anti-neutrophil cytoplasmic antibody (ANCA)-positive small vessel vasculitis or by anti-glomerular basement membrane disease. The cornerstone of treatment of both diseases is high-dose glucocorticoids. Here, we present a rare case where a patient developed pulmonary renal syndrome months after successful treatment for eosinophilic pneumonia. Case The patient is a 65-year-old female with a history of COPD who was admitted to the ICU with rapidly increasing oxygen requirements and acute encephalopathy. Chest CT revealed diffuse, bilateral, reticulonodular infiltrates. CBC with differential revealed peripheral eosinophilia at 3300/uL. Bronchoscopy was performed and BAL revealed eosinophilic predominance on cytology. She improved with IV methylprednisolone and was discharged to a skilled nursing facility with a prednisone taper. Six months later, she re-presented to the ED with sepsis secondary to UTI and AKI. After roughly 1 week of hospitalization, she developed rapidly increasing oxygen requirements and was transferred to the ICU. CT scan of her chest again revealed diffuse reticulonodular pattern of infiltrate throughout both lungs. She was intubated for worsening oxygen requirements and underwent bronchoscopy, which showed significant bloody secretions. BAL revealed positive ANA and C-ANCA titers. Cytology revealed neutrophilic predominance on her differential. Her AKI progressed and ultimately required renal replacement therapy. Work-up for the etiology of her AKI was unrevealing. Renal biopsy was deferred due to the patient’s significant anemia and thrombocytopenia. She was treated for pulmonary renal syndrome with IV methylprednisolone. Her respiratory status improved and she was able to be extubated and was eventually discharged to a long-term care hospital. Discussion Both eosinophilic pneumonia and pulmonary renal syndrome are rare, potentially lethal diseases. Six months after treatment of her eosinophilic pneumonia, she developed pulmonary renal syndrome without significant eosinophilia ruling out eosinophilic granulomatosis with polyangiitis. This is a unique case of a patient who had both eosinophilic pneumonia and pulmonary renal syndrome. The case highlights the importance of avoiding anchor bias in patients with a history of a rare disease.