Induced sputum cytology and pulmonary function tests in ex-smoker asthmatic patients controlled with inhaled steroid and long acting beta agonist therapy

Aim: The relationship between induced sputum eosinophil-neutrophil number and pulmonary function are investigated in ex-smoker asthmatic patients controlled with inhaled steroid and long acting beta agonist therapy (ICS+LABA). Method: 25 asthma patients with asthma diagnosis observed between November 2013 and November 2014, known that used ICS+LABA at least 3 months, have no attack in last month, ex-smoker (used 5-20 packet-year) and with asthma control test ≥20 were included to this study. Induced sputum cytology, pulmonary function tests were made to all patients. Age, gender, induced sputum eosinophil and neutrophil number, FEV 1 , FVC, RV and RV/TLC values were recorded. The relationship between sputum eosinophil-neutrophil number and pulmonary function test parameters were investigated. Results: 17 (68%) were female, 8 (32%) were male and mean age was 49.7±13.6. Mean sputum eosinophil percentage was 9.4±16.7 and neutrophil percentage 71.4±20.5. The positive correlation was established between induced sputum eosinophil percentage values and FEV 1 (r=+0.472; p=0.01) and FVC (r= +0.502; p= 0.01). There was no correlation between FEV 1 /FVC, RV, and RV/TLC counts and induced sputum eosinophil percentage (p>0.05). Also there was no correlation between induced sputum neutrophil number and FEV 1 , FVC, FEV 1 /FVC, RV and RV/TLC counts (p>0.05). Conclusion: The correlation of induced sputum eosinophil levels with FEV 1 and FVC demonstrated in this study means that ex-smoker controlled asthmatic patients with ICS+LABA therapy might have high level of FVC and FEV 1 but they continue to have elevated level of eosinophils.