EXHALED NITRIC OXIDE LEVELS AND THEIR ASSOCIATION WITH TRIPLE THERAPY OUTCOMES IN PATIENTS WITH FREQUENTLY EXACERBATED CHRONIC OBSTRUCTIVE PULMONARY DISEASE AT CAN THO UNIVERSITY OF MEDICINE AND PHARMACY HOSPITAL
Main Article Content
Abstract
Background: Fractional exhaled nitric oxide is a noninvasive biomarker of type-2 airway inflammation and may reflect corticosteroid responsiveness in chronic obstructive pulmonary disease. Objectives: To describe exhaled nitric oxide levels and associated factors in patients with frequently exacerbated chronic obstructive pulmonary disease, and to evaluate the outcomes of triple therapy and their association with changes in exhaled nitric oxide levels. Materials and methods: A crosssectional observational study was conducted in 96 patients with frequently exacerbated chronic obstructive pulmonary disease, including a subgroup of 40 patients who were prospectively followed at 1 and 3 months after initiation of triple therapy. Results: The mean FeNO was 25.95 ± 10.45 ppb; 60.4% of patients had FeNO ≥25 ppb. FeNO was significantly higher in patients with asthma features, chronic rhinosinusitis, and blood eosinophil count (BEC) ≥300 cells/µL. FeNO showed a strong positive correlation with BEC, and BEC was markedly higher in the FeNO ≥25 ppb group. FeNO increased with higher mMRC and CAT scores, with significant differences between higher score categories. After treatment, CAT and FeNO decreased significantly at 1 and 3 months, while mMRC decreased significantly after 3 months. No correlation was observed between changes in FeNO and changes in mMRC and CAT scores. Conclusion: FeNO may serve as a complementary biomarker for identifying eosinophilic phenotype and guiding ICS use in frequently exacerbated chronic obstructive pulmonary disease; however, it should not be used as a standalone marker of treatment response.
Keywords
Fractional exhaled nitric oxide, inhaled triple therapy, chronic obstructive pulmonary disease
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