Molecular evidence that the hepatitis C virus replicates in the oral mucosa

Background/Aims: Patients infected with the hepatitis C virus (HCV) often have extrahepatic manifestations, which significantly contribute to HCV-related morbidity, but whose pathogenesis is largely unknown. Our aim was to evaluate the HCV replication in oral mucosa of chronic hepatitis C patients. Methods: We collected oral mucosa specimens from 17 anti-HCV-positive and four anti-HCV-negative patients. Fifteen had oral lichen (12 anti-HCV-positive). Total mucosa RNA was extracted and analyzed for presence and titer of genomic and negative-strand HCV RNA. Findings were compared with clinical and pathological features. Results: Genomic and negative-strand HCV RNA were detected, respectively, in 12 of 17 (70.6%) and four of 17 (23.5%) specimens from the chronic hepatitis C patients. No negative-strand HCV RNA was detected in five anti-HCV-positive patients without lichen (including three with normal mucosa). Presence and titer of the negative-strand HCV RNA were independent of HCV genotype, serum viral load, and histological diagnosis of liver lesions. The phylogenetic analysis of the envelope 2 region cloned from a normal mucosa and the corresponding serum further suggested that only lichen tissues appear to harbor replicating HCV. Conclusions: HCV may occasionally replicate in oral lichen tissue, possibly contributing to the pathogenesis of mucosa damage. (C) 2002 European Association for the Study of the Liver. Published by Elsevier Science B.V. All rights reserved.