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

Area of Science:

• Pulmonary Medicine
• Gastroenterology
• Immunology

Background:

• Ulcerative colitis (UC) involves immune dysregulation and extraintestinal manifestations, including lung issues.
• Reduced diffusing capacity and small airway dysfunction are noted in UC patients.
• Fractional exhaled nitric oxide (FeNO) analysis may identify inflammation sites.

Purpose of the Study:

• Compare pulmonary function tests (PFTs), FeNO, and airway nitric oxide (CANO) in UC patients and healthy controls.
• Assess lung function abnormalities and subclinical airway inflammation in UC.
• Correlate lung function markers with UC clinical disease activity.

Main Methods:

• 42 UC outpatients and 41 healthy controls were enrolled.
• Pulmonary function tests (PFTs), including static volumes and diffusing capacity (DLCO), were performed.
• Fractional exhaled nitric oxide (FeNO) at various flows and C-reactive protein (CRP) were measured.

Main Results:

• UC patients exhibited significantly higher FeNO and CANO than controls (p < 0.001).
• FeNO and CANO levels increased proportionally with UC disease activity.
• Severe UC patients showed reduced total lung capacity (TLC) and DLCO (p < 0.010).

Conclusions:

• UC patients display significant lung functional abnormalities.
• Airway inflammation, indicated by elevated FeNO and CANO, correlates with UC disease activity.
• An integrated approach assessing lung function is recommended for UC patient management.