AB030. Airway involvement in a patient with ulcerative colitis

Patients with ulcerative colitis can develop pulmonary disease as a result of direct lung involvement due to the disease itself or as a complication of drug treatment. Present history: a 44-year-old man, ex-smoker, presented with gradually deteriorating shortness of breath and cough with purulent expectoration commencing 4 months earlier. Previous history: ulcerative colitis diagnosed 5 months ago under treatment with infliximab and mesalazine (poor compliance). Clinical examination: end inspiratory crackles predominately at lung bases. Absence of clubbing. Diagnostic investigation: (I) chest radiograph: reticular shadows predominately at lung bases; (II) arterial blood gasses (receiving 5 L/min via nasal cannula): pH 7.44, PCO2 36 mmHg, PO2 63 mmHg, HCO3 25 mmol/L; (III) echocardiography: normal; (IV) high resolution lung CT: bronchiectasis and diffuse centrilobular poorly defined nodules with ground glass density; (V) lung function tests: FEV1 2.2 L (60% pred.), FVC 2.6 L (58% pred.), FEV1/FVC 84%, TLC 3.44 L (51% pred.), FRC 2.32 L (69% pred.), DLCO 3.7 mL/min/mmHg (36.1% pred.); (VI) bronchoalveolar lavage: Ly 62%, Neu 3%, Eos 2%, Mφ 30% CD4/CD8 0.38; (VII) thoracoscopic lung biopsy: bronchiectasis, bronchiole smooth muscular hyperplasia and interstitial tissue thickening. Management: the patient was started on prednisolone (0.5 mg/kg of body weight) and within the next 10 days exhibited significant improvement in blood gases values (pH 7.48, pCO2 34, pO2 66 mmHg, HCO3 25 mmol/L. while breathing room air) as well as in his diffusing capacity (DLCO 14.9 mL/min/mmHg). Nevertheless, a 6 minute walking test after 10 days of therapy revealed a significantly reduced walking distance (150 m) with severe desaturation at the end of the test (drop by 7%). Airway involvement is the most common respiratory complication of ulcerative colitis and presents mainly as bronchiectasis (66%) and/or bronchiolitis. Upper airway involvement is less common. Differentiating between respiratory involvement due to ulcerative colitis itself and pulmonary toxicity due to drug treatment is not always straightforward.