Currently, one of the major indications for
liver transplantation is
infection with hepatitis C virus (HCV). Many studies have suggested that
recurrent infection with HCV is universal after
transplantation. Fastidious techniques, such as
reverse transcriptase-polymerase chain reaction (RT-PCR), have proved to be highly sensitive for detecting HCV
RNA in serum and in fresh-frozen and
formalin-fixed
paraffin-embedded (FFPE) liver tissue. In this study, we wanted to determine whether the identification of HCV
RNA in liver tissue by RT-PCR might reflect the detection of circulating HCV
RNA in blood within the tissue, rather than implying true tissue
infection. We performed RT-PCR for HCV
RNA in FFPE liver biopsy specimens taken from 14 donor allografts shortly before and immediately after implantation into recipients. The recipients were known to have HCV
RNA in serum and explanted liver tissue, as determined by RT-PCR. We were unable to detect HCV
RNA in any of the study samples, either before or after
transplantation. In a related study, qualitative and quantitative HCV
RNA analyses were performed by RT-PCR and branched
DNA (bDNA) amplification, respectively, on serum samples collected pretransplantation and immediately posttransplantation from 10 other patients who underwent
transplantation for
hepatitis C. HCV
RNA was detected in all serum samples before and after
transplantation by RT-PCR; however, the bDNA assay detected HCV
RNA in only 6 of 10 samples pre-orthotopic
liver transplantation (OLT) and in none of the immediately post-OLT samples. In our system, despite the RT-PCR detection of HCV
RNA in serum before and after the
transplantation, HCV
RNA is not detectable in the peripheral blood that accompanies
formalin-fixed liver tissue. This implies that RT-PCR detection of HCV
RNA in tissue reflects true liver
infection, rather than contamination by HCV
RNA in accompanying peripheral blood.