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Background: Hepatitis C virus genome (HCV-RNA) has been detected in whole salivary gland tissue of chronically infected patients. However, contamination of the tissue by plasma or blood cells was not excluded by the previous reports., Aims: To assess whether HCV infects the salivary gland epithelial cells in patients with chronic HCV liver disease., Methods: Twenty unselected patients with chronic active hepatitis (11 cases) or active cirrhosis (nine cases) were examined. Serum and saliva samples were obtained from all patients, 12 of whom (seven, chronic active hepatitis; five, active cirrhosis) underwent salivary gland biopsy. PCR for HCV-RNA was performed on RNA extracted from serum, saliva and salivary gland epithelial cells collected by isokinetic gradient separation after trypsin digestion of whole salivary gland tissue. Saliva samples were also examined for the presence of secretory IgA anti-HCV by gel chromatography and ELISA testing., Results: HCV-RNA was detected in all sera with titers ranging from 5.42 x 10(5) genome equivalents/ml to 123.2 x 10(5) genome equivalents/ml. Thirteen patients were infected with genotype 1b, four patients had genotype 1a, two patients had genotype 2a and one patient was unclassifiable. Low titer HCV-RNA (<2 x 10(5) genome equivalents/ml) was detected in 3/20 saliva samples (15%) from highly viremic patients infected with 1b genotype. RNA extracted from salivary gland epithelial cells consistently tested negative for HCV-RNA. In addition, all saliva specimens tested negative for secretory-IgA (S-IgA) anti-HCV, even after a 10-fold concentration of the samples., Conclusions: There was no evidence that HCV infects the salivary gland epithelial cells in our viremic patients with HCV chronic liver disease. Low level HCV-RNA in saliva is most probably due to virus spillover from blood.

The polymerase chain reaction (PCR) was used to investigate the presence of positive and negative hepatitis C virus (HCV) RNA strands in serum and peripheral blood mononuclear cells (PBMC) of 20 patients with histologically proven HCV-related chronic liver disease. All patients completed a course of interferon (IFN) treatment (6 MU of IFN-alpha 2b three times a week for 24 weeks) and were followed-up for 12 months after treatment was discontinued. Pre-treatment, end-treatment and 6-month follow-up serum and PBMC samples were examined. At enrollment, the positive strand of HCV-RNA was detected in serum of 18 patients (90%), the negative strand in none. Positive-stranded HCV-RNA was detected in PBMC of 15 patients (75%), 13 of whom also had detectable levels of negative-stranded HCV-RNA in PBMC. By the end of the treatment, 12 patients (60%) were responders. The pre-treatment HCV infection of PBMC, indicated by the presence of both RNA strands, was found in 8 (66.7%) responders compared to 5 (62.5%) non-responders (P = n.s.). End-treatment loss of PBMC HCV-RNA correlated significantly with the response since it occurred in all responders compared to 2 non-responders (P = 0.02). However, end-treatment-negative serum and PBMC HCV-RNA did not predict the occurrence of a sustained response, which was observed at month 12 in 5 of 12 responders (P = n.s.). On the other hand, the persistent absence of HCV RNA in serum and PBMC at the end of the 6-month follow-up was significantly associated with the occurrence of a sustained response (P < 0.0001).