P0653 - Non-Rheumatological Cause of Biopsy-Proven Pulmonary Vasculitis in Ulcerative Colitis

Introduction: Inflammatory bowel disease (IBD) like ulcerative colitis (UC) have thoracic manifestations of the large and small airways, pulmonary vasculature, lung parenchyma, and serosa, such as bronchiectasis, chronic bronchitis, interstitial lung disease, cryptogenic organizing pneumonia, and necrosis1. These manifestations can mimic other diseases or be related to IBD drug treatment. Correct identification of disease etiology ensures adequate treatment and avoidance of irreversible damage.

Using laboratory and histological data can aid in differentiating various etiologies. We describe a patient with UC who presented with pleuritic chest pain and multiple pulmonary consolidations without infectious or malignant findings. Eventual lung biopsy demonstrated necrosis with granulomatous inflammation suggesting vasculitis but found to be sulfasalazine pulmonary toxicity. Known sulfasalazine adverse effects include pulmonary toxicity and blood dyscrasias with at least 50 reported cases of lung toxicity2.

Case: 22-year-old female with three-year history of UC on sulfasalazine 2g BID presents with epigastric, back, chest pain, exacerbated by deep breathing and positioning. She vapes with nicotine and THC. Recent disease activity assessment showed worsening of her UC with plans to start immunomodulators.

On examination, she was in no acute distress, afebrile, respiratory rate 18, SpO2 99% on room air, BP 118/72 mmHg, and pulse 96. Physical exam was unremarkable with no chest or abdominal findings. CXR demonstrated multifocal patchy consolidations (Image 1) and CT pulmonary angiogram showed no pulmonary embolism but multifocal consolidations (Image 2). CT abdomen showed stranding in the small bowel consistent with enteritis. Labs significant for elevated D-dimer 2.95 mcg/mL, lipase 198 units/L, CRP 9.15 mg/dL, ESR 22 mm/h, and negative RVP.

Patient admitted for presumed acute pancreatitis, multifocal pneumonia vs. vaping-related injury in the setting of UC flare.

GI and pulmonology were consulted. Sulfasalazine was held. Thoracentesis demonstrated bloody exudative fluid with 13,000 WBCs, 69% neutrophils, and no malignant cells. Viral/fungal workup was negative. Echocardiogram showed no valvular vegetations. BAL/biopsy was negative for microbiology and malignant cells. Inflammatory and autoimmune differentials were considered. VATS with biopsy showed coagulative necrosis with acute and granulomatous inflammation and vasculitis, suggestive of granulomatosis with polyangiitis (GPA). Labs showed positive ANA, negative ANA panel, normal complement levels, and negative ANCA; findings consistent with sulfasalazine toxicity. Subsequent imaging demonstrated improvement in previous lung findings with corticosteroid treatment (Images 1, 2).

Discussion:
IBD patients can develop several inflammatory lung complications secondary to the disease or treatments with sulfasalazine. Sulfasalazine toxicity has clinical and histological features that mimics GPA, but ANCA negative.

Conclusion: Our patient exemplifies sulfasalazine toxicity mimicry in histological features to GPA despite ANCA negative. Discontinuing sulfasalazine and starting corticosteroids led to improvement. Extraintestinal manifestations of IBD or treatment adverse effects should always be considered with new pulmonary symptoms or abnormal radiographic findings.