Serological and salivary markers compared with biochemical markers for monitoring interferon treatment for hepatitis C virus infection.

Paired serum and saliva specimens were collected on a regular basis from 18 asymptomatic blood donors participating in a controlled clinical trial of interferon alpha 2a (IFN) treatment of chronic hepatitis C virus (HCV) infection. Nine patients were randomised to receive interferon and nine to observation only. Serum and salivary HCV RNA was detected by a "nested" polymerase chain reaction (PCR) assay. Complete follow-up data were available for 14 patients (7 treated and 7 untreated). Serum ALT levels declined to normal in five of the seven IFN-treated patients by the twelfth week. Of these five, loss of hepatitis C viraemia was observed in three. Of the seven treated patients, the three responders had a lower viraemia level than the partial or nonresponders. Both nonresponders had infection with type 1 HCV, but the complete and partial responders were infected with types 2 or 3. HCV RNA was detected in the saliva of all seven observation patients during the follow-up period. HCV was also detected in the saliva of the two patients who did not respond to IFN treatment. No correlation was shown between the level of HCV RNA in serum and the presence of HCV RNA in saliva. A role for noninvasive salivary investigations in monitoring treatment is possible, but further refinement of the methodology is required.