ĐÁNH GIÁ SỰ TƯƠNG ĐỒNG GIÁ TRỊ CỦA CHỈ SỐ NỒNG ĐỘ NITRIC OXIDE TRONG KHÍ THỞ RA VÀ SỐ LƯỢNG BẠCH CẦU ÁI TOAN MÁU TRONG CHỈ ĐỊNH ĐIỀU TRỊ DỰ PHÒNG ĐỢT CẤP BỆNH PHỔI TẮC NGHẼN MẠN TÍNH BẰNG PHÁC ĐỒ CÓ CORTICOSTEROID DẠNG HÍT

Abstract

Background: In addition to the well-established role of blood eosinophils, fractional exhaled nitric oxide, a noninvasive inflammatory biomarker, has been proposed as a potential alternative or complementary tool to guide inhaled corticosteroid use for the prevention of exacerbations in chronic obstructive pulmonary disease. Objectives: 1. To evaluate the concordance between fractional exhaled nitric oxide levels and blood eosinophil counts; 2. To determine the optimal FeNO cut-off values for guiding inhaled corticosteroid therapy based on blood eosinophil thresholds in the prevention of COPD exacerbations. Materials and methods: A cross-sectional descriptive study was conducted in 64 patients with chronic obstructive pulmonary disease. Results: Among the 64 COPD patients, 60.9% had FeNO levels ≥25 ppb, with a mean age of 67.38 ± 9.81 years. Patients with FeNO ≥25 ppb had higher rates of smoking, asthma, and chronic rhinosinusitis, along with higher mMRC scores and lower FEV₁ values. Blood eosinophil counts differed significantly between FeNO groups, with the FeNO ≥25 ppb group predominantly exhibiting blood eosinophil counts ≥300 cells/µL. FeNO showed a strong positive correlation with blood eosinophil counts (r = 0.819). The optimal FeNO cutoff values for predicting inhaled corticosteroid indication were 26.5 ppb for blood eosinophils ≥300 cells/µL and 12.7 ppb for blood eosinophils ≥100 cells/µL, both demonstrating high sensitivity and specificity. Conclusion: FeNO levels are strongly correlated with blood eosinophil counts in patients with chronic obstructive pulmonary disease and represent a valuable noninvasive biomarker to support guidance on inhaled corticosteroid use for the prevention of COPD exacerbations.