Mannitol Bronchoprovocation Challenge Ancillary Study/ACRN

Mannitol Bronchoprovocation Challenge Ancillary Study Protocol to Best Adjustment Strategy for Asthma Over Long Term

This is an ancillary study conducted as part of the BASALT trial [NCT00495157].

The overall hypotheses are: 1) an indirect airway challenge procedure using mannitol can safely characterize asthma phenotypes, predict asthma control and exacerbations, predict responses to interventions, and perform more specifically than a direct methacholine challenge and; 2) PX27 pore function in whole blood correlates with measures of airway hyperresponsiveness induced by methacholine and/or mannitol challenges

Inclusion Criteria:

• all subjects randomized to the BASALT protocol

Exclusion Criteria:

• positive urine pregnancy test
• requirement for more than two albuterol treatments for reversal of the methacholine bronchoprovocation challenge procedure at visit 4 in the BASALT parent trial