Difficult to treat asthma at high altitude

Background: Patients with difficult-to treat asthma remain symptomatic despite the use of high doses of currently available medication. They have greater morbidity,and poorer quality of life than patients with milder forms of the disease, and consume a disproportionate amount of healthcare resources for asthma. Patients with difficult-to-treat asthma form a heterogeneous group, and phenotyping is necessary in order to increase our understanding of the disease and develop novel treatments. Interesting, a proportion of patients with difficult-to-treat asthma seem to improve during treatment at high altitude. However the characteristics of these patients and the mechanisms by which they improve are still largely unknown.

Objective of the study:

1. Can difficult-to-treat asthma be divided in different phenotypes with different responses to high altitude treatment?

2. Are there specific markers or clinical characteristics in patients with difficult-to-treat asthma that predict the short term and longterm effect of high altitude treatment?

3. Is the response to high altitude treatment associated with changes in the level of activated vitamin D?

Study design:

In this longitudinal, prospective, 15 months follow up study, the patients will be assessed at entry and after 6 and 12 weeks of a standard rehabilitation programme at high altitude in the Dutch Asthmacentre Davos, and thereafter at discharge, and dutring 12 months at sea level at 3-monthly intervals.

15 months follow up study

Patients will be assessed at entry and after 6 and 12 weeks of a standard rehabilitation programme at high altitude in the Dutch Asthmacentre Davos, and thereafter at discharge, and dutring 12 months at sea level at 3-monthly intervals.

Integrated multidisciplinary assesment of the asthma-control status, asthma history, asthma specific health status,
co-morbidity, asthma- triggering factors, medication need, lungfunction,
inflammation markers and excercise tolerance.

The pulmonary rehabilitation, according to ERS guidelines, will be adjusted to this integrated assessed profile of the patient in the allergen and pollutionfree high altitude climate in Davos with low relative humidity during 12 weeks.