Associação do polimorfismo de IL-13 (+1398A/G) com a asma e a ancestralidade genômica / Association of IL-13 (+1398A/G) gene polymorphisms with asthma and genomic ancestry

Introdução: A asma é uma doença complexa, resultante da interação entre fatores genéticos e ambientais. A expressão aumentada de genes relacionados à inflamação define as alterações celulares e estruturais do aparelho respiratório, enquanto o meio ambiente modula os diferentes fenótipos asmáticos. Os produtos dessas células envolvidos na inflamação incluem citocinas, como a interleucina13 (IL-13), que está relacionada com a síntese direta de IgE, imunoglobulina essencial na patogênese da asma. Há divergências entre a prevalência da asma e o grupo étnico estudado, desta forma, o uso de Marcadores Informativos de Ancestralidade (AIM ­ Ancestry Informative Markers) possibilita a caracterização da ancestralidade genômica de diferentes populações. Objetivos: Verificar a associação entre polimorfismos do gene IL-13R com a ancestralidade genômica e a asma em uma população no sul da Bahia. Métodos: Foram genotipadas 320 amostras, sendo 114 casos, e 206 controles, utilizando o método de PCR e PCR/RFLP em sete AIMs (Sb19.3, APO, AT3, RB2300, LPL, CKMM e PV92) que apresentam elevado diferencial de frequência alélica entre africanos, ameríndios e europeu, e um polimorfismo no receptor de IL-13 (IL-13RA1). Resultados: Os resultados desse estudo mostraram que a maior contribuição foi ameríndia, tanto para os casos (37,42%), como para os controles (50,52%), demonstrando que há diferenças nas contribuições étnicas das amostras da região estudada. O polimorfismo no receptor de IL-13 (IL- 13RA1) apresentou associação significativa com rinite e história familiar. Conclusões: A heterogeneidade da composição étnica das amostras pode ter influenciado na não associação das duas variáveis: níveis de IgE sérico e histórico familiar, e a presença do polimorfismo no receptor da IL-13RA1, e aponta a necessidade de realização do controle genômico.

Introduction: Asthma is a complex disease resulting from the interaction between genetic and environmental factors. Increased expression of inflammatory genes defines cellular and structural changes in the respiratory tract, while the environment modulates the different asthmatic phenotypes. Cell products involved in inflammation include cytokines, such as interleukin-13 (IL-13), which is related to the direct synthesis of IgE, an immunoglobulin that plays a key role in the pathogenesis of asthma. Because there is divergence of asthma prevalence between different ethnic groups, the use of ancestry informative markers (AIMs) allows for the characterization of genomic ancestry in different populations. Objectives: To examine the association of IL-13R gene polymorphisms with genomic ancestry and asthma in a population from the south of Bahia. Methods: A total of 320 samples, 114 cases and 206 controls, were genotyped using PCR and PCR/RFLP methods for 7 AIMs (Sb19.3, APO, AT3, RB2300, LPL, CKMM, and PV92) that showed a high allele frequency differential between Africans, Amerindians, and Europeans and 1 polymorphism in the IL-13 receptor (IL-13RA1). Results: Amerindian ancestry provided the greatest contribution in both cases (37.42%) and controls (50.52%), indicating that there are differences in the ethnic contribution of the samples from the study region. The IL-13 receptor (IL-13RA1) polymorphism was significantly associated with rhinitis and family history. Conclusions: Heterogeneity in the ethnic composition of the samples may have influenced the non-association of serum IgE levels and family history with the presence of IL-13RA1 receptor polymorphism, and the results point to the need for genomic control.

Interleukin-1 beta and interleukin-6 gene polymorphism associations with angiographically assessed coronary artery disease in Brazilians.

The inflammatory process has been considered an important mediator for the development of atherosclerosis. Interleukin-1 beta (IL1B) is a precursor of interleukin-6 (IL6) in the acute phase of inflammatory response and their levels are elevated in patients with coronary artery disease. The aim of the present study was to further investigate the association of IL-1B and IL-6 gene polymorphisms and angiographically assessed coronary artery disease (CAD) in African- and Caucasian-Brazilians. This report analyzed the IL-1B-511C>T and IL-6-174G>C polymorphisms in 667 patients (253 African-Brazilians and 414 Caucasian-Brazilians) who underwent coronary angiography. Patients with a coronary obstructive lesion 50% presented a higher frequency of the IL-1B-511CC genotype (30.4%) compared to lesion-free individuals (16.5%, p=0.032) in African- but not in Caucasian-Brazilians. No significant genotype frequency difference was identified for the IL-6-174G>C polymorphism in either ethnic groups. However, after correction for other CAD risk factors using multivariate logistic regression, both the IL-1B-511CC [Odds ratio (OR)=2.3; p=0.019] and the IL-6-174GG (OR=2.0; p=0.028) genotypes were considered independent CAD risk predictors in African-Brazilians. This report shows that the IL-1B-511C>T and IL-6-174G>C polymorphisms were associated with CAD risk in African-Brazilians and no association was detected among Caucasian-Brazilians.

International course on emerging viruses in the Amazon region.

The international course Emerging Viruses: Global Approaches and Specificities of the Amazon Region was held in Porto Velho, Rondonia, Brazil, November 17-December 7, 2007. Organized as part of the Amsud-Pasteur research collaboration program (sponsored by Institut Pasteur), the course was held there primarily because Rondonia State is located in the Amazon region, a particular environment in which new viruses could emerge as a consequence of ecologic changes brought about by exploration and other human activities.