Le profil génétique de l’asthme atopique

Abstract

Atopy is a common familial syndrome that is due to interacting genetic and environmental factors. The atopic diseases include asthma, atopic dermatitis and allergic rhinitis. The aim of this study was to investigate the potential link between -590C/T and RsaI-in2 and, the levels of IgE and IL-4, atopic asthma in a young adult population. A total of 80 patients with atopic asthma and 80 non-atopic, nonallergic and non-asthmatic controls and 12 families in which at least one of their children was asthmatic were include. Atopic asthma status was confirmed by means of the skin prick test, The IgE levels were measured by Quantia IgE immunoturbidimetric assay, while, Interleukin (IL)-4 concentrations were determined by immunosorbent assay. IL-4 C-590T and RsaI-in2 polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism method (RFLP-PCR) using the BsmF1 and RsaI enzymes. Our findings revealed that women are much more likely to develop asthma than men. Gene analyses reviled that, the IL-4 C-590T SNP shows a significant difference between asthmatic and controls when comparing the TT vs. CC (OR, 3.63; OR 95% CI, 1.16-11.63; p-value =0.01) and TT vs. CT (OR, 2.48; OR 95% CI, 0.91 -6.95; p-value =0.05) genotypes. We also demonstrated that patients with heterozygous CT (55%) and homozygous TT (23.75%) genotypes of the IL-4 C-590T polymorphism showed significantly higher of IgE levels (pvalue =0.0000) and serum levels of IL-4 (p-value =0.0000). Whereas, for the second polymorphism no statistically significant difference between the asthma and the expression of RsaI-in2 polymorphism it was found that AA vs. BB (OR, 0.89; IC à 95% de 0.31 à 2.49; p-value = 0.82), BB vs. AB (OR, 1.21; IC à 95% de 0.48 à 3.04; p-value =0.67), AA vs. AB+BB (OR, 0.76; IC à 95% de 0.37 à 1.57; p-value =0.46), and AA+AB vs. BB (OR, 1.10; IC à 95% de 0.45 à 2.68; p-value = 0.82). By against, a highly significant association was observed between the IgE, IL-4 serum levels and AA, AB, BB genotypes when comparing the asthmatiques group and controls the results were as follows (p-value =0.0000) for IgE and (p-value =0.0000) for IL-4. While for the family study our data found that, the T allele is associated with atopic diseases and herited from the mothers. Whereas for the RsaI-in2 polymorphism our results show that, this polymorphism is associated with atopy and that the mutated allele B is not only maternally inherited, but rather inherited from both parents.