RESUMO
BACKGROUND/AIMS: Killer cell immunoglobulin-like receptors (KIR) are involved in the activation/inhibition of NK cells through an interaction with HLA class I molecules on target cells. Our study aimed to evaluate the association between KIR gene polymorphisms and the response of patients with CHC to antiviral therapy. METHODS: We compared the frequency of KIR genes, as well as that of compound KIR/HLA-C genotypes, between groups of patients with CHC who presented a sustained virological response (n=66) and who were non-responders to a combination of pegylated or standard interferon and ribavirin (n=101). KIR and HLA-C genotyping were performed using commercial kits. RESULTS: We detected a greater frequency of the KIR2DL5 gene among non-responders to antiviral therapy compared with sustained virological responders (68.3 vs. 40.9%) (P<0.001). We used multiple logistic regression analysis to determine the association between therapy response and the presence of KIR2DL5, after a control for potentially confounding variables (genotype, alcohol, fibrosis, gender, age, ethnic background and route of HCV infection). The results confirmed the strong association between the presence of KIR2DL5 and the non-response to antiviral treatment (P=0.001). CONCLUSIONS: Host genetic factors may be associated with a non-response to antiviral therapy. KIR2DL5 is a candidate gene involved in immunomodulation associated with non-response to antiviral therapy.
Assuntos
Antivirais/uso terapêutico , Antígenos HLA-C/genética , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/genética , Polimorfismo Genético , Receptores KIR2DL5/genética , Adulto , Idoso , Estudos de Coortes , Farmacorresistência Viral/genética , Quimioterapia Combinada , Feminino , Frequência do Gene , Antígenos HLA-C/efeitos dos fármacos , Hepacivirus/efeitos dos fármacos , Hepacivirus/genética , Hepatite C Crônica/diagnóstico , Humanos , Interferon alfa-2 , Interferon-alfa/uso terapêutico , Masculino , Pessoa de Meia-Idade , Polietilenoglicóis/uso terapêutico , Valor Preditivo dos Testes , Probabilidade , Prognóstico , Receptores KIR2DL5/efeitos dos fármacos , Receptores de Células Matadoras Naturais/efeitos dos fármacos , Receptores de Células Matadoras Naturais/genética , Proteínas Recombinantes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Ribavirina/uso terapêutico , Estatísticas não Paramétricas , Falha de Tratamento , Resultado do Tratamento , Carga Viral/efeitos dos fármacosRESUMO
The expression of NK cells activation receptors was assessed by comparative study of two groups of women workers at a chemical reagents factory, located in Zapopan, Jalisco, Mexico. Twenty of them were exposed to environmental toxics identified and quantified by gas chromatography, and 20 women unexposed to toxic substances. The expression of the surface markers CD56+ and CD3+, and of the activation receptors and co-receptors on NK cells was quantified by flow cytometry. To assess the cellular damage produced by chronic exposure to the toxics, the thiobarbituric acid reacting substances (TBARS) generated and the total plasma antioxidizing capacity (TPAC) were quantified in both groups. The exposed women had been exposed at least to 12 volatile toxic compounds, benzene, benz(a)pyrene, ethylbenzene, dimethylbenz(a)anthracene, xylene, toluene, styrene, chloroform, formaldehyde, iodine, chlorine and fluorine. Significant difference between the two groups was in the proportion of CD3 lymphocytes, 72.7+/-10.3% in the unexposed women versus 66.8+/-7.9% in the exposed group (p<0.05). The density of expression of NKG2D and NKp30 receptors was significantly higher in the unexposed women compared to the exposed group: NKG2D were 31.3+/-6.3 and NKp30 were 9.5+/-5.2 in the unexposed women and 5.14+/-2.9 (p<0.01) and 4.6+/-1.9 (p<0.05), respectively in the exposed women. No statistically significant differences were found in the expression of NKp80, NKp46 and 2B4 receptors. The concentration of TBARS was lower in women from the unexposed group than the corresponding data from women of the exposed group. However, no significant difference was observed in TPAC between the two groups studied. The results of this preliminary study suggest that from the five activation receptors and co-receptors of NK cells evaluated (NKp30, NKp46, NKp80, NKG2D and 2B4), only NKp30 and NKG2D receptor expression was diminished in women exposed to toxics when compared with data from unexposed women. These results suggest that the occupational exposure to mixture of toxics is one of the important factors in the diminution of the NK cell receptor expression.