The Development of a Clinical Test to Assess the Inflammatory Phenotype of Asthma

The Development of a Clinical Test to Assess the Inflammatory Phenotype of Asthma

The purpose of this study is to determine the type and degree of inflammatory parameters in peripheral blood of asthma patients compared to analysis of induced sputum.

115 asthma patients visiting the outpatient clinic of the University Medical Center will be included. Blood samples are obtained and sputum induction is performed.

Hypothesis: in asthma the analysis of type and degree of inflammation in peripheral blood by changes in phenotypes of leukocytes is at least as reliable as analysis of cells obtained from induced sputum

Asthma is a heterogeneous disease and can be classified by level of control, disease severity and the inflammatory phenotype. However, these different domains overlap and classification of patients according to these characteristics has caused confusion in the literature. Concerning the inflammatory phenotype international consensus is present regarding the diagnostic power of induced sputum. This methodology is, however, difficult to implement in general practice. Local inflammation is associated with a complex combination of systemic pro- and anti-inflammatory signals that induce changes in responsive leukocytes. These changes can be used as read-out for type and degree of inflammatory disease. Hypothesis: This will facilitate the diagnosis of inflammatory phenotypes in asthma, as general application of induced sputum is not feasible.

Goals

1. To investigate whether analysis of antibodies directed against active Beta-1 and Beta-2-integrins (CD29/CD18) and FcγRII (CD32) of primed eosinophils allows the diagnosis of eosinophilic asthma as compared to analysis of sputum eosinophilia.
2. To evaluate the applicability of antibodies against active β1/β2-integrins and FcγRII in symptomatic asthma patients as a test to diagnose eosinophilic and neutrophilic asthma.
3. To determine specific protein profiles in serum of asthma patients by proteomics for the development of a diagnostic test.
4. To evaluate the effectiveness of this new test in comparison with FeNO.

Inclusion Criteria:

• Adult asthma
• Aged 18-75 years
• Visiting the outpatient clinic of the UMCU

Exclusion Criteria:

• Smoking at present or in the last 12 months
• Past smoking history of > 10 Pack years
• AB treatment for RTI in past 4 weeks
• ABPA