RESUMO
OBJECTIVES: Oral Lichen Planus (OLP) is associated with hepatitis C virus (HCV) infection and resembles graft-versus-host disease (GVHD) both clinically and histologically. The killer cell immunoglobulin-like receptor (KIR) genes encode a family of receptors expressed on NK and T cells and are supposed to play a significant role in GVHD and HCV infection. The aim of this study was to analyze the association among OLP, HCV infection and variants in KIR gene expression. METHODS: A total of 81 patients with OLP (36 HCV+ve and 45 HCV-ve) and 217 healthy controls (HCV-ve) were typed for the presence of eight KIR genes and of HLA-Cw* alleles by polymerase chain reaction-sequence specific primer. RESULTS: There were no significant differences in the frequency of the KIR genes and HLA-C1/C2 group alleles between cases and controls. We only found a significant difference in the frequency of the gene KIR2DL2 between HCV+ve and HCV-ve OLP patients. CONCLUSIONS: The present data suggest that OLP is not associated with particular KIR genes or with HLA-Cw* alleles in patients without HCV infection. Contrarily, the role of the genes in OLP-HCV+ve patients remains unclear and might warrant further researches.