Keywords: Asthma
Airway inflammation
Eosinophils
CD8+ cells
Anti-IgE
Sputum
Bronchial biopsies
Airway hyperresponsiveness
PEF-variability
Allergen challengeThree aspects of airway inflammation in asthma were investigated in this thesis: proof of concept, monitoring and management.

In chapter 2 is shown that IL-5 is mainly effective in the circulation.

In chapter 3 is shown that steroids improve airway hyperresponsiveness, sputum eosinophils, and NO. The changes were not related. This suggests that these markers may provide different information when monitoring anti-inflammatory treatment in asthma.

In chapter 4 is shown that alpha-2-macroglobulin is an appropriate marker for measuring microvascular leakage in sputum. This "dual induction" model may used when testing the antiexudative effect of drugs.

Chapter 5 demonstrated that the annual decline in FEV1 is related with CD8+ cells. This suggests that inflammatory phenotypes in asthma may have prognostic relevance.

In chapter 6 is shown that PEF-variability provides information about asthma severity. Therefore, the current guidelines for the treatment of asthma can be improved by including PEF-variability.

In chapter 7 is shown that anti-IgE improves PEF, diminishes allergen responses and is paralleled by a reduction in eosinophils in biopsies and sputum and a decline in IgE+ cells. This suggests that the clinical benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE bearing cells.