Intrahepatic Hepatitis C Virus Replication Correlates with Chronic Hepatitis C Disease Severity In Vivo

Abstract

The role of viral factors in the pathogenesis of chronic hepatitis C is unknown. The objective of the present study was to characterize markers of hepatitis C virus (HCV) infection and replication in liver biopsy specimens obtained from 65 genotype 1-infected subjects, including 31 who were coinfected with human immunodeficiency virus (HIV), and to analyze associations between intrahepatic viral markers and hepatitis C disease severity. The percentages of liver cells harboring HCV genomes (%G) and replicative-intermediate RNAs (%RI) were evaluated using strand-specific in situ hybridization, while HCV core and NS3 antigens were assessed by immunocytochemistry. HIV-positive and HIV-negative subjects had similar mean grades and stages of liver disease and had similar indices of HCV infection and replication in liver, even though coinfected subjects had significantly shorter mean disease duration (P ‫؍‬ 0.0003). Multivariate analysis showed that %G was not associated with grade or stage of liver disease (P ‫؍‬ 0.5 and 0.4, respectively), while %RI was strongly associated with liver inflammation (P < 0.001), liver fibrosis (P < 0.001), and serum alanine aminotransferase levels (P ‫؍‬ 0.01). NS3 antigen (but not core) was more frequently detected in HCV RI-positive versus RI-negative specimens (P ‫؍‬ 0.028). These findings demonstrate a link between HCV proliferation and hepatitis C disease severity and suggest similar pathogenic mechanisms in HIV-positive and HIV-negative individuals.Hepatitis C is a chronic progressive disease of the liver that is caused by infection with hepatitis C virus (HCV) (9). Although 15 to 20% of individuals infected with HCV spontaneously clear the virus in the acute phase, up to 85% develop persistent viremia. Approximately 60% of those infected develop clinically overt chronic hepatitis, and in this group, the rate of liver disease progression is generally slow but variable (34a). Approximately 20% of patients with chronic hepatitis C develop cirrhosis within 20 years of infection, and those with cirrhosis are at risk of clinical decompensation and developing hepatocellular carcinoma. Finally, chronic hepatitis C occurs in up to 30% of individuals with human immunodeficiency virus (HIV) infection, and evidence to date suggests that HCVassociated liver disease is more severe in subjects with HCV/ HIV coinfection than in subjects with HCV monoinfection. The mechanisms driving HCV disease acceleration in coinfected subjects are presently unknown (17).As with other members of the Flaviviridae family, HCV replicates by enzymatically converting its positive-strand RNA genome into a complementary or minus-strand replicativeintermediate RNA (RI RNA) and then copying the minusstrand RNA to produce new progeny plus-strand RNA. Nascent HCV genomes are then packaged into virions that are released from infected cells by unknown mechanisms. For positive-strand RNA viruses such as HCV, the RI RNA is a highly specific index of active viral replication (26). Based on in vitro experiments using the HCV r...

Cell-Cell Contact-Mediated Hepatitis C Virus (HCV) Transfer, Productive Infection, and Replication and Their Requirement for HCV Receptors

“…In chronically HCV-infected liver, viral replication and the intrahepatic HCV RNA level are very low (7 to 64 genomic equivalents per cell) (57,58), and nAbs and other immunological responses are often present (59). However, even with the presence of those nAbs that are capable of neutralizing cell-free infectivity in vitro (15), the prevalence of infected hepatocytes in the livers of chronically infected patients is normally high (57,60). Our data show that cell-cell contact facilitates HCV spreading among hepatocytes ( Fig.…”

“…4). Previous studies have shown that discrete, localized infectious foci and a gradient dispersion of the viral genome around the center of the foci are observed in patient liver biopsy specimens (58,60,61) and that CCCM HCV infection is relatively less sensitive to nAbs and neutralizing patient sera than cell-free HCV infection (62). Taken together, it is highly conceivable that CCCM HCV occurs in vivo, and it could even be more favorable than cell-free infection, given the compact nature of the liver.…”

Hepatitis C Virus Proteins Inhibit C3 Complement Production

“…Although HCV RNA has been identified in hepatocytes from patients with chronic infection (32), only a small number of cells are found to express viral antigens by using conventional immunohistochemical methods or fluorescence microscopy (21,39). A combination of 2-photon (2-PE) microscopy and virus-specific, fluorescent, semiconductor quantum dot (Qdot) probes has been used to determine the proportion of virus-infected hepatocytes (23).…”

Hepatitis C viral kinetics in special populations

“…Thus, theoretically, patients with a high fraction of HCV-infected hepatocytes will have high ε c and hence will have a poorer chance of achieving SVR. Interestingly, Pal et al [47] showed that advanced liver disease is associated with a higher fraction of HCV-infected hepatocytes and lower SVR rates (<29%) than for patients without liver disease [25,26,48,49].…”