Analysis of cytokine gene polymorphisms in oral lichen planus HCV-infected patients

Oral Lichen Planus (OLP) is frequently associated to hepatitis C virus (HCV) infection. In a previous work, we have shown that the IFN-g and TNF-a gene polymorphisms contribute to OLP susceptibility in absence of HCV infection. (OLP-HCV-ve). The aim of this study was to evaluate whether the polymorphisms of several cytokine genes may influence the susceptibility to OLP in HCV-infected patients. (OLP-HCV+ve). Analysis of 22 polymorphisms inside 13 cytokine genes was performed with "University of Heidelberg Cytokine Typing Tray" (PCR-SSP method). Were included in the study group: 35 OLP-HCV+ve; 44 OLP-HCV-ve and 140 healthy subjects. All were HLA-DRB1- low resolution molecular typed. No significant difference was evident in OLP-HCV+ve patients and healthy controls, whereas IFN-g UTR 5644 genotype A/T frequency showed a significant increase in OLP-HCV+ve patients in comparison to OLP-HCV-ve (45,7% vs 18,2%, p=0,003). Contrarily, genotype G/A frequency of the -308 TNF-a gene was lower in OLP-HCV +ve patients than in OLP-HCV-ve (5,7% vs 43,2, p=0,00006). A linkage disequilibrium between allele A of the -308 TNF-a and HLA-DR3 and -DR6 patients was observed only among OLP-HCV-ve. patients. All those data suggest distinct pathogenetic mechanisms between OLP in patients with and without HCV infection.