TT virus detection in oral lichen planus lesions

Epidemiological studies have demonstrated a correlation between oral lichen planus and different liver diseases. The new virus termed TT virus (TTV) i s highly prevalent in patients with chronic hepatitis of different etiology and it may be speculated that TT virus may be involved in the pathogenesis of oral lichen planus. This study examined the presence of TT vi rus DNA i n serum by PCR and in oral mucosa biopsies by in situ hybridization from 20 patients with oral lichen planus (13 with chronic hepatitis and seven with out liver disease). Serum and oral mucosa biopsies from six patients all wi th chronic hepatitis with leukoplakia were also studied as controls. TT vir us DNA was positive in the serum of 17/20 (85%) of the patients with oral l ichen planus and in all the controls. TT virus DNA hybridization signals we re detected in mucosa biopsies from all the patients with TT virus DNA in s erum but in none of the th ree cases without this marker. The percentage of positive cells ranged from 1.6-80%. No differences were found in the perce ntage of positive cells between rr virus positive patients with and without oral lichen planus and there was no relationship between the number of pos itive cells and the intensity of the inflammatory infiltrate. In conclusion , TT virus infects oral epithelial cells but the results do not support a r ole for TT virus in causing oral lichen planus. (C) 2001 Wiley-Liss, Inc.