Clinical and atopic parameters and airway inflammatory markers in childhood asthma: a factor analysis

• Published in: Thorax Vol. 60; no. 10; pp. 822 - 826
• Main Authors: Leung, T F, Wong, G W K, Ko, F W S, Lam, C W K, Fok, T F
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group Ltd and British Thoracic Society 01.10.2005; BMJ; BMJ Publishing Group LTD; BMJ Group
• Subjects: Administration, Inhalation; Adolescent; Adrenal Cortex Hormones - administration & dosage; airway inflammation; Airway management; Asthma; Asthma - diagnosis; Asthma - physiopathology; BHR; Biological and medical sciences; Biomarkers - blood; BMI; body mass index; bronchial hyperresponsiveness; Bronchitis - diagnosis; Bronchitis - physiopathology; Chemokines; Chemokines - metabolism; Child; children; Childrens health; Chronic Disease; Chronic obstructive pulmonary disease, asthma; Disease; EBC; Enzymes; exhaled breath condensate; exhaled nitric oxide; factor analysis; Factor Analysis, Statistical; FEno; FEV1; Forced Expiratory Volume - physiology; forced expiratory volume in 1 second; forced vital capacity; FVC; Humans; Hypersensitivity, Immediate - diagnosis; Hypersensitivity, Immediate - physiopathology; Hypotheses; Immunoassay; Leukotriene B4 - metabolism; lung function; macrophage derived chemokine; MDC; Medical sciences; Nitric oxide; Nitric Oxide - metabolism; Plasma; Pneumology; TARC; thymus and activation regulated chemokine; Vital Capacity - physiology; United States > US; Human; Allergy; Immunopathology; Lung disease; Factor analysis; Respiratory disease; Biological marker; Cardiovascular disease; Inflammation; Asthma; Atopy; Bronchus disease; Parameter; Obstructive pulmonary disease; Child
• ISSN: 0040-6376; 1468-3296
• DOI: 10.1136/thx.2004.039321

Background: Recent studies have repeatedly shown weak correlations among lung function parameters, atopy, exhaled nitric oxide level (Feno), and airway inflammatory markers, suggesting that they are non-overlapping characteristics of asthma in adults. A study was undertaken to determine, using factor analysis, whether the above features represent separate dimensions of childhood asthma. Methods: Clinically stable asthmatic patients aged 7–18 years underwent spirometric testing, methacholine bronchial challenge, blood sampling for atopy markers and chemokine levels (macrophage derived chemokine (MDC), thymus and activation regulated chemokine (TARC), and eotaxin), Feno, and chemokines (MDC and eotaxin) and leukotriene B4 measurements in exhaled breath condensate (EBC). Results: The mean (SD) forced expiratory volume in 1 second (FEV1) and Feno of 92 patients were 92.1 (15.9)% predicted and 87.3 (65.7) ppb, respectively. 59% of patients received inhaled corticosteroids. Factor analysis selected four different factors, explaining 55.5% of total variance. The Kaiser-Meyer-Olkin measure of sampling adequacy was 0.587. Plasma total and specific IgE levels, peripheral blood eosinophil percentage, and Feno loaded on factor 1; plasma TARC and MDC concentrations on factor 2; MDC, eotaxin and leukotriene B4 concentrations in EBC on factor 3; and plasma eotaxin concentration together with clinical indices including body mass index and disease severity score loaded on factor 4. Post hoc factor analyses revealed similar results when outliers were excluded. Conclusions: The results suggest that atopy related indices and airway inflammation are separate dimensions in the assessment of childhood asthma, and inflammatory markers in peripheral blood and EBC are non-overlapping factors of asthma.