Association of HLA-G 14bp insertion/deletion and TGF-β1 polymorphisms with atopic asthma monosensitized against Der p 1: An Algerian study with a review of the literature
التفاصيل البيبلوغرافية
العنوان:
Association of HLA-G 14bp insertion/deletion and TGF-β1 polymorphisms with atopic asthma monosensitized against Der p 1: An Algerian study with a review of the literature
Introduction Genetic diversity of HLA-G consists of sequence variations in promoter, exonic and 3′ untranslated (3′UTR) regions. Polymorphisms in the HLA-G promoter region had previously been associated with asthma. Of interest is also the fact that the genes encoding the effectors IL-10 and TGF-β1 (immunosuppressive molecules controlling the immune response in respiratory allergy) also exhibit genetic polymorphisms in populations. Objectives To investigate the potential role of the 14-bp insertion/deletion polymorphism in conjunction with IL-10 and TGF-β1 genes polymorphisms in respiratory allergy development. Methods The study involved 125 patients suffering from atopic asthma, all monosensitized against Der p 1 and 100 matched-controls, all originating from Algeria. PCR-based techniques were used to assess HLA-G, IL-10 and TGF-β1 genotypes. Results While the frequency of IL-10 gene polymorphisms did not differ between patients and controls, 3′UTR +14 bp insertion allele was significantly more frequent in patients group than in control group (P = 0.006) with the homozygous state of the 14-bp deletion allele being more frequent in controls (P = 0.02). TGF-β1 +869T/C polymorphism analysis showed a significant difference between allergic patients and controls for TC genotype (P = 0.03). Discussion Our findings suggest that HLA-G gene may participate in the pathogenesis of asthma in our population. A possible mechanism is that diminished immunosuppressive activity, mediated by HLA-G, may contribute to initiation/persistence of chronic airway inflammation in asthma. On the other hand, TC/GG are less frequent in atopic patients than in controls. This can be explained by the association of this haplotype with a high production of TGF-β1.
