Proof of concept study to evaluate step-down therapy with inhaled corticosteroid alone or additive therapy on surrogate inflammatory markers in asthma.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Much of the focus of inflammatory surrogates and airway challenges in asthma has been directed towards success of therapy and diagnosis. Few have considered them in the context of guiding dose reduction once sufficient control has been achieved. WHAT THIS STUDY ADDS: Adenosine monophosphate (AMP) as an indirect bronchial airway challenge, together with non invasive inflammatory surrogate measures were not found to be clinically useful when guiding therapy in a group of asthmatic patients through step 3-4 in British Thoracic Society asthma guidelines. However, they may still play a role in predicting failure of individual step-down. AIM: The aim of the study was to evaluate the usefulness of inflammatory surrogates in determining step-down therapy in asthma.
METHODS: AMP challenge, serum eosinophil cationic protein (ECP), exhaled nitric oxide (eNO) and pulmonary function tests were recorded. Subjects were divided into two groups following high dose inhaled corticosteroids (ICS): Group A fixed dose ICS vs. Group B ICS alone and in combination with add on therapies.
RESULTS: No differences were seen in inflammatory measures between fixed dose ICS and reduced dose ICS alone or with combination therapies.
CONCLUSIONS: AMP challenge conferred no additional benefit in guiding step-down therapy. The role of inflammatory surrogates may still play a role in predicting failed step-down on an individual basis.