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A6542 - Interstitial Lung Disease in a Patient with Quiescent Ulcerative Colitis
Author Block: K. P. Chen1, D. Kahn2; 1Department of Medicine, Danbury Hospital, Danbury, CT, United States, 2Pulmonary and Critical Care Medicine, Danbury Hospital, Danbury, CT, United States.
Introduction: Interstitial lung diseases (ILD) are known complications in patients receiving mesalamine or biologics for treating inflammatory bowel disease (IBD). However, lung involvement may be more prevalent than previously believed as many patients will have impaired diffusion capacity. Lung involvement can also develop in the absence of significant IBD activity.
Case presentation: A 50-year-old female was referred for progressive dyspnea on exertion over 4 months. It was associated with dry cough, but without night sweats or weight loss. She has mild ulcerative colitis, which has not required medical treatment recently. She had pregnancy-associated DVT, not currently anticoagulated. There is no allergies. She is a visiting nurse. She is a never smoker but had childhood passive smoking exposure. On exam, she has a BMI of 30.5, respiratory rate of 20, and saturation of 92% while breathing ambient air. Cardiopulmonary exam, CBC, chemistry, and pro-BNP were normal. PPD test was negative. Her PFT showed severely reduced diffusion capacity, mild restriction, and normal spirometry. Her CXR was unremarkable. A CTA revealed no PE, with diffuse ground glass opacities, mosaic attenuation, and mediastinal lymphadenopathy. She was referred for open lung biopsy, which revealed diffuse cellular interstitial pneumonia, small non-necrotizing granulomas, and patchy organizing alveolitis. Further laboratory workup revealed elevated ESR (41) and CRP (37.4), but negative ANA, ANCA, and RF. Her ACE-1 was elevated at 88.
The patient’s dyspnea and hypoxemia worsened during the 2-week workup period and she was given supplemental oxygen. Oral steroid treatment was started after the biopsy.
Discussion: The lung is a rare site for extra-intestinal manifestations of IBD. However, there is a high prevalence of impaired diffusion capacity among patients with IBD, often asymptomatic. When ILD is diagnosed in patients with IBD, it is often attributed to medication exposure or associated vasculitis. Nonetheless, ILD is reported to develop even when the IBD is quiescent and not being treated. The radiographic and histopathologic features of ILD associated with IBD can be varied, including UIP, COP, NSIP, eosinophilic pneumonia, or Langerhan’s granulomatosis. The disease progression is usually subacute, but it has also been reported to present acutely with ARDS or air leak syndrome. It can ultimately progress to fibrotic stage and cause significant debilitation. Therefore, to recognize and treat the lung complication of IBD that is steroid-responsive is important.
These patients tend to have dysregulated immune system profile. Environmental allergens and viral infections can serve as precipitants triggering dysregulated immune cascade.