RESUMO
BACKGROUND: IL-13 has been implicated in the pathogenesis of asthma and in the regulation of IgE synthesis in humans. Single nucleotide polymorphisms (SNPs) in the IL-13 gene have been associated with asthma and total serum IgE level in Caucasian populations. OBJECTIVE: To test for genetic association between an SNP in exon 4 of the IL-13 gene (IL-13 + 2044 or Arg130Gln) and total serum IgE level and asthma-related phenotypes in a population with high prevalence of asthma living in Costa Rica. METHODS: Family-based association study. RESULTS: Among 83 Costa Rican school children with asthma and their parents (249 individuals), there was no evidence of linkage disequilibrium between the IL-13 + 2044 SNP and any of the outcomes of interest (total serum IgE level on a logarithmic scale, number of positive skin tests to aeroallergens, and asthma). These results were not significantly changed after adjustment for age and gender. CONCLUSIONS: No significant evidence of linkage disequilibrium between an SNP in exon 4 of the IL-13 gene and total serum IgE level, sensitization to allergens or asthma was found in a family-based association study in Costa Rica.
Assuntos
Imunoglobulina E/sangue , Imunoglobulina E/genética , Interleucina-13/genética , Núcleo Familiar , Polimorfismo Genético/genética , Alérgenos/genética , Alérgenos/imunologia , Asma/genética , Asma/imunologia , Criança , Proteção da Criança , Costa Rica/epidemiologia , Saúde da Família , Feminino , Frequência do Gene , Genótipo , Humanos , Imunoglobulina E/imunologia , Interleucina-13/imunologia , Desequilíbrio de Ligação/genética , Desequilíbrio de Ligação/imunologia , Masculino , Polimorfismo Genético/imunologia , Testes CutâneosRESUMO
BACKGROUND: Little is known about factors determining the pathogenesis and severity of asthma in Latin American countries. Costa Rica, one of the most prosperous Latin American nations, has a very high asthma prevalence. OBJECTIVE: To examine the relation between potential risk factors and childhood asthma in Costa Rica. METHODS: Cross-sectional study of 214 schoolchildren aged 10 to 13 years participating in phase II of the International Study of Asthma and Allergies in Childhood. RESULTS: After adjustment for age, gender, area of residence, maternal smoking during pregnancy, and airway responsiveness to hypertonic saline solution, sensitization to house dust mites was associated with asthma (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.1 to 4.4; p = 0.02). In the multivariate analysis, parental education no higher than high school (OR, 3.0; 95% CI, 1.4 to 6.4; p < 0.01) and parental history of asthma (OR, 2.6; 95% CI, 1.3 to 5.2; p < 0.01) were also independent predictors of childhood asthma. CONCLUSIONS: Sensitization to house dust mites, low parental education, and parental history of asthma are associated with asthma in Costa Rica.