Symptom evaluation during the methacholine test: Does it add to the interpretation of the test results based on the PC20FEV1?

The occurrence of asthma-like symptoms during the methacholine test was associated with milder airway hyperresponsiveness that would go unnoticed by the PC20FEV1. This finding suggests that SNRs should not be merely classified as having normal responsiveness, as currently recommended, but further assessed for airway inflammation. Our results helped planning a longitudinal study to investigate the prognostic validity of this approach.