Discordance between asthma control clinical, physiological and inflammatory parameters in mild asthma

Discrepancies have been observed between clinical, physiological, and inflammatory asthma control criteria, mostly in asthmatic subjects using regular inhaled corticosteroids (ICS) treatment. This study compared the prevalence of discrepancies between these 3 control parameters in mild asthmatic subjects not taking ICS.

A retrospective analysis of demographic data and results from the Asthma Control Scoring System tool was performed in mild patients with asthma not taking ICS. The % score obtained for the clinical (symptoms), physiological (FEV1), and inflammatory (sputum eosinophil percentage) criteria were compared. Discrepancy was defined as a >20% difference between any 2 scores.

Data from 213 subjects with mild asthma were analysed. Discrepancies between clinical and inflammatory scores were observed in 32% of subjects, whereas 31% showed discrepancies between physiological and inflammatory scores, and 20% between clinical and physiological scores. Sub-analysis of the discrepancy groups showed that respectively 88% and 89% of subjects had a higher clinical or physiological score than inflammatory score. Twenty-seven percent of subjects had residual airway inflammation despite adequate clinical control and optimal pulmonary function.

There are significant discrepancies between scores of subjective and objective asthma control criteria. Airway inflammation often persists in subjects with good clinical or physiological asthma control scores. The consequences of this persisting airway inflammation in mild patients remain to be further studied.