Detection of hepatitis C virus RNA in oral lichen planus and oral cancer tissues.

Hepatitis C virus (HCV) infection not only causes chronic liver diseases but shows extrahepatic manifestations as oral lichen planus (OLP) and oral cancer. To elucidate the direct relationships among these diseases and HCV infection, we investigated the detection of positive- and negative-strand HCV-RNA from serum, OLP (n=19), and oral cancer (n=17) tissues. We used a sensitive reverse transcription to polymerase chain reaction (RT-PCR) method, and analyzed sequences from the HCV El/E2 region of the genome from serum and tissue. Positive and negative HCV-RNA strands were observed in 13 (92.9%) and 3 (21.4%) OLP tissues, respectively. In oral cancer tissues, positive HCV-RNA strands were detected in all tissues from anti-HCV positive patients. Negative HCV-RNA strands were observed in 5 of 7 (71.4%) patient's tissues. Furthermore, it was confirmed that the sequence from one of each OLP and oral cancer patient differed between serum and tissue HCV-RNA. These results may indicate that HCV persists and replicates in these lesions, suggesting a pathological role for HCV, although the mechanisms are unclear.