IL-4 receptor genetic polymorphisms and asthma in Asian populations.

Background: IL-4 receptor alpha chain is crucial for the binding and signaling of IL-4, which mediates isotype switching and IgE production. The gene of IL-4 receptor alpha chain is a candidate gene for asthma and atopy.

Objectives: To determine whether Ile50Val and Q576R polymorphisms of IL-4 receptor alpha chain gene were associated with asthma and higher level of total IgE in Chinese, Malay and Indian populations.

The E237G polymorphism of the high-affinity IgE receptor beta chain and asthma.

Background: The beta chain of high-affinity IgE receptor (FcepsilonRI beta) has been proposed as a candidate gene for asthma and atopic diseases.

Objectives: To determine the prevalence of the E237G polymorphism of the FcepsilonRI beta gene and to investigate its association with asthma and total IgE levels in 3 Asian populations.

Methods: A total of 291 asthmatic patients (141 Chinese, 68 Malay, and 82 Indian) and 355 asymptomatic blood donors (157 Chinese, 100 Malay, and 98 Indian) were recruited.

Epidemiology of respiratory viruses in patients hospitalized with near-fatal asthma, acute exacerbations of asthma, or chronic obstructive pulmonary disease.

Purpose: We compared the prevalence and spectrum of common respiratory viruses among patients with near-fatal asthma, acute exacerbations of asthma, or chronic obstructive pulmonary disease (COPD), and the relation of these findings to acute respiratory symptoms.

Methods: We obtained adequate samples of respiratory secretions from 17 patients hospitalized with near-fatal asthma, 29 with acute asthma, and 14 with COPD. We used a polymerase chain reaction-based method to test for six common respiratory viruses in samples from endotracheal tube aspirates from patients with near-fatal asthma, and from induced sputum specimens from patients with acute asthma or COPD.

Comparison of three methods for respiratory virus detection between induced sputum and nasopharyngeal aspirate specimens in acute asthma.

Viral respiratory tract infections are associated frequently with acute exacerbations of asthma. Nasopharyngeal aspirates and bronchoalveolar lavage specimens are used extensively for detecting viral respiratory tract infections, but not sputum. The aim of the study was to determine the efficiency of viral detection in induced sputum versus nasopharyngeal aspirate obtained during acute exacerbations of asthma, comparing three laboratory methods of viral diagnosis.