Predictable Factors Related to Reversibility in Young Patients with Chronic Airflow Obstruction

Lee, Shin Seok; Choi, Inseon; Kang, Yoo Ho

Abstract

Smoking-related chronic obstructive pulmonary disease (COPD) and chronic asthmatic bronchitis, which are the most important causes of chronic airflow obstruction (CAO), can occur together in the same patient and the prognoses of COPD and chronic asthmatic bronchitis are different each other. To estimate the extent of asthmatic component in young patients with CAO and to evaluate the role of allergy as a predictable index of reversibility in airflow obstruction, 80 CAO patients who were less than 40 years old were examined retrospectively.According to the definition of reversibility as a 15% improvement in FEV1 above baseline with an absolute increase of at least 200ml, 28 patients (35%) responded to inhaled salbutamol (acute responder). And 10 out of 16 patients (62.5%), who were not responded significantly to inhaled bronchodilator and performed a follow-up lung function study, responded to antiasthma therapy including corticosteroids for 3~4 weeks (chronic responder). There were significant differences in past history of asthma, wheezing on auscultation, peripheral blood eosinophil counts, positive skin prick tests or MAST tests between acute responder and acute non-responder. And past history of asthma and peripheral blood eosinophil count were different between chronic responder and chronic non-responder. In univariate analysis, significant predictors of acute bronchodilator response included past history of asthma, wheezing on auscultation, peripheral blood eosinophil counts, positive skin prick tests or MAST tests and in multivariate models, significant predictor was positive skin tests or MAST tests. In conclusion, 75.6% of patients with CAO who were less than 40 years old had an asthmatic component and presence of atopy among the several allergy markers was most important predictor to bronchodilator response.