Differences between obstructive asthma and Asthma-COPD overlap syndrome (ACOS)

Abstract

Background: Differences between obstructive asthma and asthma-COPD overlap syndrome (ACOS) are poorly known. Aims: To evaluate these differences in Seinajoki Adult-onset Asthma Study (SAAS) cohort. Methods: 257 patients were diagnosed with new-onset adult asthma during 1999-2002. After 12 years (2012-2013) patients (n=203) were re-evaluated, and 2 groups of patients were chosen for analysis: 1) non-smoking asthmatic patients with fixed obstruction ( 1 /FVC 1 /FVC Results: ACOS patients had lower pulmonary diffusing capacity and higher number of comorbidities as compared to asthmatics with fixed obstruction. Levels of blood neutrophils and interleukin-6 (IL-6) were higher in the ACOS-group. Levels of blood eosinophils, IgE, high sensitivity CRP (hsCRP) or FeNO did not differ between the groups (Table 1). Conclusion: ACOS differs from non-smoking asthmatics with fixed obstruction most significantly by lower diffusing capacity, higher levels of blood neutrophils and IL-6, and by higher number of comorbidities. Shown are median (IQ range) or mean ± SD