Thromboxane A2 receptor polymorphism is associated gene with the serum concentration of cat-specific immunoglobulin E as well as the development and severity of asthma in Chinese children
PEDIATRIC ALLERGY AND IMMUNOLOGY
Authors: Leung, TF; Tang, NLS; Lam, CWK; Li, AM; Chan, IHS; Ha, G
Abstract
Thromboxane A2 and its receptor (TBXA2R) are involved in the constriction of vascular and respiratory smooth muscles. The T924C polymorphism in the TBXA2R gone was recently found to be associated with asthma in Japanese adults but not in children. Its relationship with atopy or asthma severity in children has not been defined. To investigate this further, we first assessed the severity of asthma in Chinese children using a standardized questionnaire modified from the Disease Severity Score and spirometric evaluation. Then, peripheral blood was analyzed For serum total and aeroallergen-specific immunoglobulin E (IgE) levels, and TBXA2R T924C genotypes were determined by restriction fragment length polymorphism (RFLP) analysis. One-hundred and fifty three asthmatic patients and 57 control children were recruited, of respective mean ages 9.9 and 11.0 years (p = 0.07). The mean logarithmic serum total IgE concentration was 2.57 and 2.09, respectively, for the asthmatic group and control group (p <0.0001). Atopy was detected in 132 (86%) asthmatics and 33 (58%) controls. A significant association was observed between T924C and the diagnosis of atopic asthma (p = 0.044, odds ratio: 1.84). In addition, those asthmatics homozygous for the mutant allele in T924C had a lower forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) (p = 0.032 and 0.002, respectively). Among our asthmatic patients, the TBXA2R T924C polymorphism correlated with the concentration of cat-specific IgE in serum (p = 0.046). Nonetheless, this gene marker did not show an association with the scrum total IgE concentration or any clinical indicator of asthma severity. In conclusion, our results suggest that the T924C marker in the TBXA2R gene is associated, in Chinese children, with an increased susceptibility of developing atopic asthma. This marker is also associated with the extent of allergic sensitization to cat, as well as with reduced FEV1 and FVC values.
What do we know about the genetics of aspirin intolerance?
JOURNAL OF CLINICAL PHARMACY AND THERAPEUTICS
Authors: Palikhe, N. S.; Kim, S. -H.; Park, H. -S
Abstract
Although acetylsalicylic acid is prescribed for a broad range of diseases, it can induce a wide array of clinically recognized hypersensitivity reactions, including aspirin-intolerant asthma (AIA) with rhinitis and aspirin-intolerant urticaria (AIU) with anaphylaxis. Altered eicosanoid metabolism is the generally accepted mechanism of aspirin intolerance; the overproduction of cysteinyl leucotrienes has been suggested to play a causative role in both AIA and AIU. Genetic markers suggested for AIA include HLA-DPBI*0301, leucotriene C4 synthase (LTC4S), ALOX5, CYSLT, PGE2, TBXA2R and TBX21. Similarly, HLA-DB1*0609, ALOX5, FCER1A and HNMT have been identified as possible genetic markers for AIU. An additional low-risk genetic marker for AIA is MS4A2, which encodes the beta-chain of FCER1. Other single and sets of two or more interacting genetic markers are currently being investigated. Analyses of the genetic backgrounds of patients with AIA and AIU will promote the development of early diagnostic and therapeutic interventions, which may reduce the incidence of AIA and AIU.