Virological features of hepatitis C virus infection in hemodialysis patients

Abstract

The clinical and epidemiological relevance of circulating antibodies to hepatitis C virus (HCV) in hemodialysis patients is uncertain, since clinical signs of infection are often mild or absent, with alanine aminotransferase (ALT) values that are virtually always normal, and liver biopsies are only rarely performed. Determination of HCV RNA in serum is therefore critical for distinguishing chronic HCV infection from previous exposure to the virus. We studied HCV viremia by reverse transcription polymerase chain reaction (RT-PCR) in the 5'-noncoding region of the viral genome in 77 dialysis patients who were screened for anti-HCV by a second-generation enzyme-linked immunosorbent assay (the enzyme immunoassay II; Ortho HCV, 2nd generation, Ortho Diagnostic Systems Raritan, N.J.) and a second-generation recombinant immunoblot assay (Chiron Corporation and Ortho Diagnostic Systems) and prospectively evaluated for ALT elevations over a period of 5 years. Of 77 patients tested, 29 (38%) had active infection as shown by a positive PCR assay result, and of these, 26 were anti-HCV positive. Although a good correlation was found between circulating anti-HCV and HCV RNA in serum, 10 (28%) of 36 anti-HCV-positive patients were HCV RNA negative by PCR, suggesting either low levels of viremia or past exposure to HCV and subsequent recovery. On the other hand, 3 (7.3%) of 41 anti-HCV-negative patients had HCV RNA in their sera, indicating seronegative HCV infection. The ALT level had no predictive value for HCV infection, because it was repeatedly normal in 18 (62%) of 29 viremic patients. HCV genotyping was also performed and indicated that all four known genotypes of HCV were present in our group. In conclusion, serological assays are reliable for detecting exposure to HCV in hemodialysis patients; however, direct identification of the viral genome is required to document current infection.

Differential humoral immune response against hepatitis C virus antigenic synthetic peptides in infected patients with and without mixed cryoglobulinaemia

“…Nested polymerase chain reaction (PCR) amplification of the core region of HCV with type-specific primers was performed on all plasma samples according to the method of Okamoto et al [21,22], with minor modifications. Briefly, type III/2a specific primer was modified according to Silini et al [23], because of the nucleotide differences between type III/2a Italian and Japanese isolates. HCV genotypes were defined according to Simmonds et al [24].…”

Rapid genotyping of hepatitis C virus RNA‐isolates obtained from patients residing in Western Europe

“…This observation suggests the existence of multiple subtypes among type 2 isolates in Western Europe and requires confirmation by sequence analysis of the E l and NS5B regions. Theoretically, the subtypespecific "2a" primer as described by Silini et al [1993] would not allow typing of the 3 type 2 isolates due to mismatches at essential positions (Fig. 1).…”

Hepatitis C virus infection and mixed cryoglobulinaemia: assessment of HCV RNA copy numbers in supernatant, cryoprecipitate and non‐liver cells

“…[18] reported subtypes l b and l a to be equally distributed in a small group of MC patients, the high prevalence of subtype 1 b has been reported recently by other Italian groups [25,26]. This is not surprising as genotype l b is by far the most prevalent in Italy [32]. Although exhaustive virological analyses are required to clarify this point, the observation that viruses with similar genetic characteristics are found in patients with and without MC indicates that MC occurs in HCV-infected patients independently of the viral genotype and that (in the presence of HCV infection) host factors play a crucial role in this autoimmune disorder.…”

“…HCV genotyping HCV genotyping was performed in all plasma samples by nested PCR amplification of the core region of HCV with type-specific primers, according to the method of Okamoto et al [31], with minor modifications [32]. Results were expressed according to the Simmonds genotype classification [ 3 31.…”