Korean J Asthma Allergy Clin Immunol.  2005 Sep;25(3):210-216.

IL-13 And IL-5 in Induced Sputum in Patients with Eosinophilic Bronchitis and Asthma: an Association with Airway Hyperresponsiveness

Abstract

BACKGROUND
Experimental studies on asthma have indicated that IL-13 induces airway hyperreactivity (AHR). However, it remains unproven that IL-13 is responsible for AHR of asthmatics. Eosinophilic bronchitis (EB) shows normal airway responsiveness despite eosinophilic airway inflammation with similar severity to that of asthma.
OBJECTIVE
This study evaluated the role of IL-13 in asthma by comparing the sputum IL-5 and IL-13 levels in both groups. METHOD: IL-5 and IL-13 were assayed in sputum and culture supernatants of peripheral blood mononuclear cells from 22 asthmatics, 12 EB patients, and 11 normal controls. RESULT: IL-13 level was higher in asthmatics than EB patients or normal controls (P<.05). IL-5 level was similar in asthmatics and EB patients, who had significantly higher IL-5 level than normal controls. Sputum IL-13, not IL-5, is inversely correlated with PC20 methacholine value in asthmatics (r=-0.484, P=.02). IL-13 production by peripheral blood mononuclear cells was significantly higher in asthmatics than in EB patients. CONCLUSION: These findings suggested that IL-13 may contribute to the pathogenic mechanism of AHR in asthmatic patients.

MeSH Terms

Asthma*
Bronchitis*
Eosinophils*
Humans
Inflammation
Interleukin-13*
Interleukin-5*
Methacholine Chloride
Sputum*
Interleukin-13
Interleukin-5
Methacholine Chloride