Detection of hepatitis C virus replication by in situ hybridization in epithelial cells of anti-hepatitis C virus-positive patients with and without oral lichen planus

Epidemiological studies have demonstrated that there is a correlation betwe en oral lichen planus and chronic hepatitis C virus (HCV) infection, HCV RN A has been recently detected in epithelial cells from oral lichen planus le sions by reverse-transcription polymerase chain reaction (RT-PCR). However, this technique does not discriminate which types of cells are infected by the virus or if the viral RNA is present in the serum that contaminates the biopsy. Morphological evidence of viral replication in cells from these le sions is needed to establish a role for HCV in oral lichen planus. Conseque ntly, we have analyzed the presence of positive and negative HCV-RNA strand s in oral mucosa biopsies from 23 patients (14 anti-HCV-positive) diagnosed as having oral lichen planus and from 5 patients with chronic hepatitis C without oral lichen planus. Positive and negative HCV-RNA strands were dete cted in epithelial cells of the mucosa biopsies from all anti-HCV-positive patients independently of whether or not they had oral lichen planus, but i n none of the anti-HCV-negative cases, The percentage of stained cells rang ed from 4.4% to 14.3%. These percentages do not correlate with the serum vi remia levels or the intensity of the cellular infiltrate in patients with o ral lichen planus, In conclusion, we have shown that HCV replicates in epit helial cells of patients with and without oral lichen planus. The pathologi cal consequences of this finding remain to be elucidated.