Korean J Asthma Allergy Clin Immunol.  2006 Mar;26(1):59-63.

Relationship between Clinical Characteristics and Severity of Methacholine Airway Hyperresponsiveness

Abstract

BACKGROUND
Airway hyperresponsiveness (AHR) is a key phenotype of asthma. The expression of AHR is known to be variable in asthma patients, but the underlying mechanisms are poorly understood.
OBJECTIVE
The aim of this study was to evaluate the relationship of clinical characteristics such as smoking history, duration, atopy, total IgE levels, basal lung function, disease severity, and airway inflammation with methacholine AHR in patients with asthma. METHOD: A total of 109 asthma patients underwent spirometry and methacholine bronchial provocation test (MBPT). According to PC(20), asthma patients were classified by mild AHR group (PC(20) between 4 to 25 mg/mL) and by severe AHR group (PC(20) of less than 4 mg/mL). They gave induced sputum for airway inflammation and serum for total IgE, and atopy were evaluated by the skin prick test to common aeroallergens. RESULT: Atopy and serum total IgE levels were not significantly different between the two groups. Basal FEV1 was significantly higher in mild AHR group (87.5+/-14.7%) than in severe AHR group (80.5+/-17.4%)(P=0.023). In addition, frequencies of severe severity were higher in severe AHR group than in mild AHR group (5.8% vs. 19.3%; P=0.002). The number of neutrophils and eosinophils in induced sputum was enhanced in the former group than in the latter group, although the statistical significances were not found (18.9+/-88.0 vs. 8.2+/-8.8x10(5)/g; 7.1+/-16.6 vs. 2.8+/-5.9x10(5)/g, respectively).
CONCLUSION
Basal airway obstruction and asthma severity were positively associated with severity of methacholine airway responsiveness in asthma patients.

MeSH Terms

Airway Obstruction
Asthma
Bronchial Provocation Tests
Eosinophils
Humans
Immunoglobulin E
Inflammation
Lung
Methacholine Chloride*
Neutrophils
Phenotype
Skin
Smoke
Smoking
Spirometry
Sputum
Immunoglobulin E
Methacholine Chloride
Smoke