DETECTION OF HEPATITIS-C VIRUS GENOME IN PARAFFIN-EMBEDDED TISSUES BY NESTED REVERSE TRANSCRIPTION-POLYMERASE CHAIN-REACTION

Nested reverse transcription-polymerase chain reaction (nested RT-PCR) was used to detect the hepatitis C virus (HCV) genome in formalin-fixed, paraffin-embedded (FFPE) liver specimens after total nucleic acids were extracted from the tissue by proteinase K digestion and phenol-chloroform purification. Although the sensitivity of HCV-RNA detection in FFPE tissues was 10-100-fold less than when HCV was amplified from fresh tissues, this method proved to be very useful for the detection of HCV-RNA in fixed pathological specimens. HCV-RNA was detected in FFPE liver specimens in 26 of 31 (84%) patients who were seropositive for anti-HCV. Surprisingly, it was possible to detect the HCV genome in FFPE liver tissues stored at room temperature for as long as 12 years. Furthermore, using this method in the present study, we found that nearly 79% of the HCV-RNA-positive subjects with hepatocellular carcinoma in Japan show an association with HCV type II infections. These data suggest that HCV infection may play an important role in hepatocarcinogenesis.