Pulmonary manifestations in inflammatory bowel disease: a single centre observational prospective study.

Background: up to 50% of patients affected by inflammatory bowel disease (IBD) express extra-intestinal manifestations (EIMs) involving potentially every organ. Among these, pulmonary EIMs are one of the most underdiagnosed, given their frequently poor symptomatology. Aim and methods of the study: the following study aims to deeper understand pulmonary EIMs in IBD from the point of view of epidemiology, clinics, radiology and pulmonary functional tests. In a period of fifteen months, IBD patients attending the Gastroenterology department of the University Hospital of Padua were prospectively enrolled and underwent the ATS-DLD-78-A questionnaire on respiratory symptoms, whose compilation was then followed by an interview with a lung medicine specialist (reserved to only those patients with a confirmed IBD diagnosis and reported respiratory symptoms). Subsequently, patients were invited to undergo chest imaging and pulmonary functional tests when necessary. Results: 152 people were included in the study: 55 revealed a score of 3 points or more at the ATS-DLD-78-A questionnaire (‘positive’ patients), while 97 patients scored low on the questionnaire with a score of less than 3 (‘negative’ patients). The ‘positive’ patients were younger in comparison with the ‘negative’ patients (median 46 vs. 51 years old, respectively), while no different gender distribution was recorded. The ‘positive’ patients were further categorized into two sub-groups: the poorly symptomatic (n = 25, scoring 3-6 points at the questionnaire) and the very symptomatic group (n = 30, scoring 7 or more points at the questionnaire). These two groups, as well as the entire ‘positive’ population, were tested for a series of demographic, clinical and diagnostic variables. Current smokers were 29% of the entire population. EIMs of IBD were already identified and diagnosed in 24% of the population and comorbidities were highly prevalent (occurring in 71% of the entire population). Also, familiarity for lung diseases was reported by 42% of patients (mostly distributed in the very symptomatic group, 61%). Overall, 15 of ‘positive’ patients show radiological abnormalities either on chest x-ray (in 12 out of 34 people undergoing chest x-ray) or on chest CT scan (10 out of 11 people undergoing CT scan), mostly represented by bronchiectasis and parenchymal thickening. Pulmonary functional tests showed no obstructive or restrictive ventilatory disorders, but small airways obstruction was present in a small group of patients (9 out of 28 patients who underwent pulmonary functional tests). Moreover, DLCO was impaired in 14 out of 24 people. Conclusions: almost one third of the IBD patients presents respiratory symptoms and most of them are younger adults. Familiarity for pulmonary diseases seems to be more associated with highly symptomatic IBD patients. Almost one third of the IBD population with respiratory symptoms presents radiological findings, mostly bronchiectasis. Reduced DLCO and small airways obstruction are the main functional abnormalities. Further research, maybe with a multicenter population, is needed to confirm these results.