Virological characteristics of hepatitis C virus infection in chronic hemodialysis patients: a cross-sectional study
Fabrizi, F.; Lunghi, G.; Guarnori, I.; Raffaele, L.; Di Filippo, S.; Erba, G.; Pagano, A.; Locatelli, F.
Clinical Nephrology 44(1): 49-55
1995
ISSN/ISBN: 0301-0430 PMID: 7554533 Document Number: 454789
Detection of hepatitis C virus viremia (HCV RNA) in serum of hemodialysis (HD) patients is crucial for documenting ongoing infection because the clinical and epidemiological importance of anti-HCV positivity is not clear. HCV viremia was studied in 104 HD patients by reverse transcription polymerase chain reaction (RT PCR) using primers localized in the 5' non-coding region of the viral genome. We used two different methods to detect HCV RNA: a direct PCR amplification of HCV RNA from human serum, and a standard RT PCR procedure (requiring the RNA extraction step). There were 50 (48%) anti-HCV positive patients in this population. Twenty-two (21.1%) out of 104 patients showed HCV RNA in serum by standard RT PCR technique: they belonged to the anti-HCV positive patient group, whereas all anti-HCV negative patients were HCV RNA negative. Prevalence of HCV RNA was more than doubled when standard RT PCR was used compared to direct RT PCR protocol. There was a good association between serum HCV RNA and circulating anti-HCV antibodies, tested by second-generation ELISA and RIBA assays. HCV viremia was not associated with either the presence or the absence of a particular RIBA antibody specificity. AST and ALT levels had no predictive value for HCV viremia, because they were repeatedly normal in the majority of viremic patients (16/22: 73%). We also analyzed the effect of specimen handling and storage on the rate of HCV RNA detection by standard RT PCR technique: three serum samples showed complete disappearance of HCV RNA after two freeze-thaw cycles whereas they yield positive results after a single cycle of freezing followed by thawing and RNA extraction.