Vitiligo: estresse, qualidade de vida e polimorfismo Glu298Asp no gene do óxido nítrico sintase endotelial

• Autor(a) principal: Lacerda, Kênia Alves Pereira
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/00130000096k2
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6739
• topic: Vitiligo; Qualidade de vida; Polimorfismo; Gene; Glu298Asp; Vitiligo; Quality of life; Polymorphism; Gene; Glu298Asp; CIENCIAS BIOLOGICAS::BIOQUIMICA

Vitiligo is a skin disease that affects about 1% of the population worldwide. This disease does not cause physical incapacity, but due to its disfiguring appearance, the carriers can present psychological disturbances and impairment in the quality of life. The pathogenesis has not yet been clarified. Recently, evidence has suggested that some gene polymorphisms are associated with risk of developing vitiligo. This study aimed to investigate the Glu298Asp polymorphism of the endothelial nitric oxide synthase gene (eNOS) in a group of patients with vitiligo and to compare the frequencies of the genotypes with a control group from the center-west region of Brazil, as well as assess the quality of life and the perception of stress In individuals with vitiligo and to compare the perception of stress with non-carriers. First study included 51 individuals with vitiligo and 50 controls. The whole blood samples were obtained by collection of peripheral venous blood, then DNA extraction was performed. The genotyping of the Glu298Asp polymorphism was performed by PCR-RFLP analysis. The research on the association of the polymorphism of the eNOS Glu298Asp gene with vitiligo did not present a significant difference in the distribution of genotypes and in the distribution of allelic frequencies between the carriers and the control group. However, in the analysis of the association between the genotypes and the variables location of vitiligo and skin color in the carriers, a higher proportion of TT genotypes was observed in individuals with 100% unisegmentar vitiligo and GT in patients with vitiligo located 68.3% (p = 0.028 ). Also, in the dominant model, a significantly higher proportion of GG genotype was observed in individuals of black color 34.5%, while a higher frequency of moderate-color individuals with GG + TT genotype was observed 54.5% (p = 0.035 ). In the second study, the sample consisted of 102 participants divided into two groups, with vitiligo and without vitiligo. We used the Dermatology Life Quality Index questionnaires and the Perceived Stress Scale. The mean quality of life score for patients with vitiligo was 4.7 ± 5.8, demonstrating a mild impairment in the patients. There was a significant association between quality of life and black skin color (β = 5.64, p <0.001), pattern of involvement of exposed vitiligo (β = 5.22, p <0.001) and perceived stress (β = 0,22 p = 0.033). The perceived stress assessed between the groups presented a mean of 20.7 ± 6.0 and 17.8 ± 7.0 for case and control, respectively. Vitiligo patients presented a high perception of stress when compared to the control group (β = 3.12, p = 0.022). The results pointed out a high perception of stress in vitiligo patients, evidencing that the fact of having vitiligo increases the level of stress. It is known that several factors, such as the genetic profile and ethnicity of the analyzed population, can influence the complex susceptibility to the disease, therefore, more studies are needed to elucidate the role of eNOS gene polymorphism in the pathogenesis of vitiligo.