Korean J Asthma Allergy Clin Immunol.  2005 Jun;25(2):104-109.

Methacholine-induced Bronchial Hyperresponsiveness in Patients with Main Stem Endobronchial Tumor

Abstract

BACKGROUND
Patients with main stem endobronchial tumor may have wheeze on physical examination, which mimics bronchial asthma.
OBJECTIVE
We evaluated the role of methacholine induced bronchial hyperresponsiveness, which is a hallmark of bronchial asthma, in differentiating these patients from patients with bronchial asthma. METHOD: The provocative concentrations of methacholine required to reduce FEV1 by 20% of the pre-challenge baseline (PC20) and the prevalence of hyperresponsiveness were compared among patients with main stem endobronchial tumor (n=8), patients with symptomatic bronchial asthma (n=15) and normal healthy controls (n=10). RESULT: PC20 in patients with main stem endobronchial tumor (17.2+/-3.9 mg/mL) and normal healthy controls (23.9+/-3.2 mg/mL) were significantly higher than those in patients with bronchial asthma (6.3+/-2.3 mg/mL). Prevalence of hyperresponsiveness (PC20<25.0 mg/mL of methacholine) was higher in patients with bronchial asthma than that in patients with endobronchial tumor, or normal healthy controls (86.7% vs. 37.5%, 86.7% vs. 10.0%, P<.05 respectively). There were no significant correlations between clinical parameters (FVC, FEV1, peripheral blood eosinophil count, total IgE level) and PC20 in patients with main stem endobronchial tumor. CONCLUSION: It is reasonable to consider the possibility of endobronchial tumor in patients who have wheeze on physical examination, but do not have methacholine-induced bronchial hyperresponsiveness.

MeSH Terms

Asthma
Eosinophils
Humans
Immunoglobulin E
Methacholine Chloride
Physical Examination
Prevalence
Immunoglobulin E
Methacholine Chloride