Detection of hepatitis C virus RNA in saliva samples from patients with seric anti-HCV antibodies.

We examined the frequency of HCV-RNA in saliva samples from anti-HCV positive patients. Both plasma and saliva samples from 39 HCV patients (13 with normal liver enzymes, 19 with abnormal liver enzymes and 13 with cirrhosis) were investigated. Stimulated saliva and fresh plasma were centrifuged (900 x g,10 min) and stored at -70 degrees C, after the addition of guanidine isothiocyanate RNA extraction buffer. HCV-RNA was detected by RT-nested-PCR (amplification of HCV-cDNA for two rounds, using HCV primers 939/209 and 940/211). HCV genotyping was carried out by RFLP (using Mva I and Hinf 1 or Hae III and Rsa I restriction enzymes). Thirty-two out of 39 (82%; 95% CI=70-94%) anti-HCV-positive patients had HCV-RNA in plasma samples. Eight out of 39 (20.5%; 95% CI=6.6-34.4%) had HCV-RNA in the saliva. The HCV genotype in saliva samples from these patients matched the genotype found for plasma HCV-RNA. No significant correlation between the presence of HCV and either age, gender, HCV genotype or any risk factor for HCV infection was found. The observed prevalence (20.5% of anti HCV positive patients or 25% of the patients with HCV-RNA in plasma) was lower than that previously reported from other countries. The low frequency of HCV-RNA in saliva samples observed in our study may be due to the use of cell-free saliva. Other authors reporting higher frequencies of HCV-RNA in saliva used whole saliva, without centrifugation.