Clinically masked increases in bronchial inflammation in guideline-treated persistent asthma.
BACKGROUND
Current guidelines generally recommend a combination of inhaled corticosteroids and a Beta2-agonist for persistent asthma. The adjustment of anti-inflammatory therapy in persistent asthma is advised to be guided mainly by the presence of symptoms.


OBJECTIVE
To investigate whether clinically masked increases in bronchial inflammation occur in guideline-treated, persistent asthma following allergen exposure.


METHODS
After a 4-week steroid-run-in period (fluticasone 250 microg twice daily) 48 allergic patients with persistent asthma underwent a bronchial challenge with a single dose of allergen, after inhalation of salbutamol (400 microg, nebulized dose). FEV1 and sputum markers of bronchial inflammation were measured before and after allergen challenge. Furthermore, additional rescue-salbutamol usage was recorded following allergen challenge.


RESULTS
After allergen challenge there was a significant increase in sputum eosinophil numbers (geometric mean number x 10(4)/g [95% CI]: 0.5 [0.3; 1.0] before, and 2.4 [1.3; 4.2] after challenge, p=0.01). The mean change in FEV1 between 4 and 8h after challenge relative to baseline was -0.04% [95% CI-2.3; 2.2], p>0.9. None of the patients took additional rescue salbutamol over 8 h after allergen challenge.


CONCLUSIONS
Clinically masked increases in bronchial inflammation occur in guideline-treated, persistent asthma following allergen exposure. This finding underscores the need for additional guides for the adjustment of anti-inflammatory therapy in persistent asthma.
Koopmans
Julia G
JG
Department of Pulmonology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Lutter
René
R
Jansen
Henk M
HM
van der Zee
Jaring S
JS
D000293:Adolescent; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000627:therapeutic use; D000485:Allergens / Q000276:immunology; D000730:Androstadienes / Q000494:pharmacology; D001249:Asthma / Q000150:complications / Q000628:therapy*; D001991:Bronchitis / Q000175:diagnosis* / Q000473:pathology; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000627:therapeutic use; D040002:Dermatophagoides pteronyssinus / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004804:Eosinophils / Q000276:immunology; D005260:Female; D000068298:Fluticasone; D005541:Forced Expiratory Volume / Q000187:drug effects; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011852:Radioallergosorbent Test; D012129:Respiratory Function Tests
D000485:Allergens; D000730:Androstadienes; D001993:Bronchodilator Agents; D000068298:Fluticasone; D000420:Albuterol