Subclinical Pulmonary Involvement in Active IBD Responds to Biologic Therapy

Lung Involvement in Patients with Ulcerative Colitis: Relationship between Exhaled Nitric Oxide and Lung Function

Ulcerative colitis (UC) is characterized by immune system dysregulation with frequent extraintestinal manifestations, including airway involvement. A reduction in CO diffusing capacity and functional alterations in small airways have been described. An extended analysis of fractional exhaled nitric oxide (FeNO) may distinguish the sites of production, and the presence of small airway inflammation may be a useful, non-invasive marker for patient follow-up. The aim of our study was to compare the PFTs as well as FeNO and CANO values of UC patients with different clinical disease activities and healthy subjects to reveal lung function abnormalities and the presence of subclinical airway inflammation. We enrolled 42 adult outpatients at different clinical activity stages of UC (39 ± 13 years) and a healthy control group of 41 subjects (29 ± 3 years). C-reactive protein (CRP) and FeNO values at different flows (50,100, and 200 mL/s) were collected. All patients performed pulmonary function tests (PFTs) with static volumes and diffusing capacity (DLCO). FeNO and CANO values were significantly increased in UC patients when compared with controls (p = 0.0008 and p < 0.0001, respectively) and were proportional to disease activity (FeNO class 3: 28.1 ppb vs. classes 1-2: 7.7 ppb; CANO values class 3: 8.6 ppb vs. classes 1-2: 2.7 ppb (p < 0.0001)). TLC and DLCO were significantly reduced in severe (Mayo 3) UC patients (p = 0.010 and p = 0.003, respectively). The results of this study show significant lung functional abnormalities in UC patients and suggest the presence of airway inflammation directly correlated with disease activity, suggesting the need for an integrated approach in routine assessment.

Lung Involvement in Inflammatory Bowel Diseases: Shared Pathways and Unwanted Connections

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory disorders of the gastrointestinal tract, frequently associated with extraintestinal manifestations (EIMs) that can severely affect IBD patients' quality of life, sometimes even becoming life-threatening. Respiratory diseases have always been considered a rare and subsequently neglected extraintestinal manifestations of IBD. However, increasing evidence has demonstrated that respiratory involvement is frequent in IBD patients, even in the absence of respiratory symptoms. Airway inflammation is the most common milieu of IBD-related involvement, with bronchiectasis being the most common manifestation. Furthermore, significant differences in prevalence and types of involvement are present between Crohn's disease and ulcerative colitis. The same embryological origin of respiratory and gastrointestinal tissue, in addition to exposure to common antigens and cytokine networks, may all play a potential role in the respiratory involvement. Furthermore, other causes such as drug-related toxicity and infections must always be considered. This article aims at reviewing the current evidence on the association between IBD and respiratory diseases. The purpose is to raise awareness of respiratory manifestation among IBD specialists and emphasize the need for identifying respiratory diseases in early stages to promptly treat these conditions, avoid worsening morbidity, and prevent lung damage.

Prevalence of and Factors Associated with Respiratory Symptoms Among Patients with Inflammatory Bowel Disease: A Prospective Study

BACKGROUND

No large, prospective study has investigated respiratory symptoms in patients with inflammatory bowel diseases. We aimed to describe the prevalence of and factors associated with respiratory symptoms in patients with inflammatory bowel disease.

METHODS

In an observational, prospective, cross-sectional study, we evaluated the frequency of respiratory symptoms using a validated self-reporting questionnaire from February 2019 to February 2021 during routine follow-up outpatient visits of patients with inflammatory bowel disease followed in the Gastroenterology Department of the Nancy University Hospital. In case of a positive questionnaire, patients were systematically offered a consultation with a pulmonologist in order to investigate a potential underlying respiratory disease.

RESULTS

There were 325 patients included, and 180 patients had a positive questionnaire (144 with Crohn's disease). Of the included patients, 165 (50.8%) presented with respiratory symptoms, with dyspnea being the most frequent symptom (102 patients). There were 102 patients (56.7%) who benefited from a consultation in the pulmonology department: 43 (42.2%) were diagnosed with a respiratory disease, mainly asthma (n = 13) or chronic obstructive pulmonary disease (n = 10). Fourteen patients (13.7%) had obstructive sleep apnea. A body mass index increase, being a smoker or ex-smoker, and having articular extra-intestinal manifestations were independently associated with a higher prevalence of respiratory symptoms.

CONCLUSIONS

Half of patients with inflammatory bowel disease reported respiratory symptoms in our study. Patients with inflammatory bowel disease should be systematically screened, as pulmonary disease is frequently present in this population, with specific attention being given to smokers or ex-smokers and patients with extra-articular intestinal manifestations.

Role of pulmonary function testing in inflammatory bowel diseases (Review)

Inflammatory bowel disease (IBD) is a term used to describe chronic inflammatory entities of the gastrointestinal system with an unclear etiology. Extra-intestinal manifestations beyond the involvement of the gastrointestinal tract can also occur. Several studies have investigated the alterations of pulmonary function tests (PFTs) in patients with IBD. To the best of our knowledge, the present review article is the first to summarize all the types of PFTs that have been performed in patients with IBD. Contradictory data exist regarding the association of PFT alterations with disease activity. PFT abnormalities can develop in individuals with IBD who have no clear clinical signs or radiological evidence, suggesting that PFTs may be useful in detecting latent respiratory involvement. The most prevalent finding in the PFTs of adults and children with IBD is an impairment in the diffusing capacity for carbon monoxide, although evidence on the other tests, particularly spirometric values, and their connection with disease activity is inconsistent.