Detection of hepatitis C virus in paraffin-embedded liver biopsies of patients negative for viral RNA in serum

Hepatitis E in liver biopsies from patients with acute hepatitis of clinically unexplained origin

Hepatitis E virus (HEV) is a small RNA virus and the infectious agent of hepatitis E that occurs worldwide either as epidemics in Asia caused by genotype 1 and 2 or as sporadic disease in industrialized countries induced by genotype 3 and 4. The frequency might be underestimated in central Europe as a cause of acute hepatitis. Therefore, we analyzed on liver biopsies, if cases of acute hepatitis with clinically unknown or obscure diagnosis were actually caused by the infection with HEV. We included 221 liver biopsies retrieved from the files of the institute of pathology during the years 2000 till 2010 that were taken from patients with acute hepatitis of obscure or doubtful diagnosis. From all biopsies RNA was extracted, prepared, and subjected to RT-PCR with specific primers. Amplified RNA was detected in 7 patients, sequenced and the genotype 3 could be determined in four of the seven of positive specimens from 221 samples. Histopathology of the biopsies revealed a classic acute hepatitis with cholestatic features and in some cases confluent necrosis in zone 3. Histology in a cohort of matched patients was less severe and showed more eosinophils. The analysis of the immune response by subtyping of liver infiltrating lymphocytes showed circumstantial evidence of adaptive immune reaction with CD 8 positive CTLs being the dominant lymphocyte population. In conclusion, in doubtful cases of acute hepatitis of unknown origin, HEV infection should be considered as etiology in central Europe. We demonstrate for the first time that the diagnosis can be made in paraffin-embedded liver biopsies reliably when no serum is available and also the genotype can be determined. The analysis of the immune response by subtyping of liver infiltrating lymphocytes indicates an adaptive mechanism suggesting in analogy with HAV, HBV and HCV that the virus itself is not cytopathic but liver damage is due to immune reaction.

Interaction between immunoglobulin allotypes and NK receptor genes in diabetes post-hepatitis C virus infection

Genetic interactions between natural killer (NK) cells immunoglobulin-like receptor (KIR) genes and immunoglobulin allotypes have been previously reported in type 2 diabetes mellitus (DM) patients. Puerto Rican Americans with a history of intravenous drug use who developed DM following HCV infection (n=32) were compared to individuals infected with HCV without diabetes (n=121) and to DM non-infected individuals (n=95). Subjects were genotyped for KIRs and immunoglobulin allotypes. We found interactions of immunoglobulin allotypes KM3/KM3 with NK inhibitory receptors 2DL3/2DL3, 2DL1 in the absence of 2DS4 associated with susceptibility to DM in HCV infected individuals. These data suggest the possibility that a subset of patients with HCV could have an immune-mediated component contributing to the development of DM.

Real-time quantitative assay for routine testing of HCV RNA in formalin-fixed, paraffin-embedded liver samples

The assessment of hepatitis C virus (HCV) RNA in liver tissues is clinically relevant in cases where histology, liver function tests, and HCV serology are not sufficient for a definitive diagnosis of HCV-related hepatitis. We analyzed 215 formalin-fixed, paraffin-embedded liver needle biopsies from patients infected with HCV genotypes 1b and 2. HCV RNA extracted from paraffin sections were quantified by means of a TaqMan real-time reverse transcription-polymerase chain reaction method. The quantification of HCV RNA in liver tissue was correlated with the amount of HCV detected by immunohistochemistry (IHC) on paired frozen biopsies, the HCV RNA load in the serum, and the main serum tests of liver function and cholestasis. HCV RNA was detected by real-time reverse transcription-polymerase chain reaction in 169 liver biopsies (78.6%) with a mean value of 13.59+/-37.25 IU/ng. Tissue HCV RNA levels strongly correlated with the IHC results (P<0.001, Spearman test), HCV serum load (P<0.001), aspartate aminotransferase (P=0.001), gamma-glutamyl transpeptidase (P=0.012), and aspartate aminotransferase/alanine aminotransferase ratio (P=0.029). HCV RNA was amplified in up to 7-year-old archival tissue samples. Real-time HCV RNA quantification on archival liver tissue may be clinically relevant in case of "occult" HCV infection or for the diagnosis of patients with known HCV infection and hepatic dysfunction but seronegative for HCV RNA. The assessment of the levels of HCV RNA in the liver might also be important for monitoring the effectiveness of antiviral therapy and the progression of disease in patients with chronic HCV hepatitis.

Hepatitis B virus overexpresses suppressor of cytokine signaling-3 (SOCS3) thereby contributing to severity of inflammation in the liver

The mechanism by which hepatitis B virus (HBV) infection causes severe inflammatory liver diseases is multifactorial and related to interactions with cell signaling pathways and the ensuing inflammatory response. Activation of JAK/STAT/SOCS signaling is essential for the induction of cellular antiviral responses, contributes to apoptosis and is negatively regulated by SOCS proteins. Recent reports have shown that SOCS3 activation interferes with viral protein expression and treatment response and thereby plays a major role in hepatitis virus infections. We analyzed the expression of SOCS3 in liver specimens from HBV-infected patients using immunohistochemistry (IHC) and determined the effect of HBV on STAT/SOCS signaling in functional cell culture experiments (HuH-7) using HBV-expressing adenoviral constructs (AdHBV). Increased expression of SOCS3 protein was identified in liver specimens from patients with chronic HBV-infection and this correlated with the severity of liver inflammation. In accordance with the IHC-findings, in vitro analyses demonstrated that HBV infection of HuH7 cells was associated with increased expression of SOCS3 protein. In spite of the over expression of its negative regulator SOCS3 we observed a constitutive activation of STAT3. SOCS1 levels were not increased while pSTAT1 was suppressed in HBV-infected HuH7 cells. Our results demonstrate that STAT/SOCS-signaling is dysregulated in HBV-infected hepatocytes both in vivo and in vitro and this correlated with the severity of liver inflammatory changes. This interference of STAT/SOCS signaling by HBV may result in an ineffective immune response against HBV and potentially contributes to viral pathogenesis, malignant transformation and may represent an important mechanism of viral persistence.

Persistence of hepatitis C RNA in liver allografts is associated with histologic progression independent of serologic viral clearance

Background. Hepatitis C virus (HCV) nondetectability in the liver may predict a sustained viral response (SVR) in patients with an end of treatment response. HCV RNA can be detected in liver tissue by in situ hybridization (ISH). Aim. To determine if HCV nondetectability in liver allografts by ISH can predict SVR in patients who cleared virus serologically on treatment. Methods. Twenty five patients with undetectable serum HCV on Interferon/Ribavirin therapy for HCV recurrence post liver transplant (LT) were studied. All had biopsies at 4 months post LT (baseline) and follow up with HCV ISH analysis performed. Results. 10 were ISH positive (group 1); 15 were ISH negative (group 2). Groups 1 and 2 had similar patient, donor, and viral characteristics at LT, as well as treatment duration at the time of the ISH assayed liver biopsy (13 ± 16 versus 10 ± 4 months P = .24). However, group 1 had longer total treatment duration (24 ± 10 versus 14 ± 5 months, P = .001). Eight (80%) group 1 and 9 (60%) group 2 patients achieved SVR. Mean grade and stage (modified Ishak score) were similar at 4 months, however, group 1 had higher grade (3 ± 1.7 versus 1.6 ± 1.3, P = .039) and stage (1.4 ± 1.4 versus 0.5 ± 0.6, P = .084) on the ISH assayed biopsy, after similar post LT intervals (23 ± 10 versus 24 ± 12 months, P = .91). Conclusion. Allograft HCV ISH nondetectability does not predict SVR in treatment responsive HCV recurrence, but is associated with less severe histologic disease.

Hepatocyte expression of angiotensin II type 1 receptor is downregulated in advanced human liver fibrosis

BACKGROUND

The renin-angiotensin system plays an important role in fibrosis. Angiotensin II regulates key steps in tissue remodelling processes through angiotensin II type 1 receptor (AT1R). In bile duct-occluded rats, AT1R expression is significantly decreased in advanced liver fibrosis. Therefore, we studied the AT1R expression in human liver tissue during different stages of fibrosis caused by chronic hepatitis C.

METHODS

Liver biopsy specimens from 85 patients were analysed. Real-time reverse transcription polymerase chain reaction was used to quantify AT1R mRNA. Immunohistochemical labelling of AT1R and double staining for AT1R, CD31, CD68, CD3 and fibulin-2 were performed.

RESULTS

AT1R mRNA was significantly reduced in human liver tissue with end-stage cirrhosis compared with early fibrosis. In liver cirrhosis, immunohistochemistry revealed a decreased expression of AT1R on hepatocytes, together with an increased staining intensity on myofibroblasts, vascular endothelium and bile duct epithelium.

CONCLUSION

In conclusion, AT1R expression is downregulated in human liver cirrhosis specimens because of the reduced expression levels on hepatocytes. Therefore, antifibrogenic therapy with AT1R blockers may be most promising if initiated during early stages of fibrosis.

Adiponectin inhibits steatotic CD95/Fas up-regulation by hepatocytes: therapeutic implications for hepatitis C

BACKGROUND/AIMS

Steatosis may trigger hepatocytes to up-regulate CD95/Fas thereby increasing susceptibility to apoptosis, inflammation and fibrosis. We investigated this concept and potential roles of adiponectin and its receptors (AdipoR1; AdipoR2) in chronically HCV-infected patients.

METHODS

In 98 HCV+ patients and 20 controls, sera were tested for HCV genotypes, FFAs, adiponectin and the M30 apoptosis indicator, and biopsies were evaluated for steatosis/inflammation/fibrosis, CD95/Fas (mRNA/protein), adiponectin (mRNA/protein), AdipoR1/-R2 (mRNA) and M30 (protein). We also questioned whether adiponectin protects HepG2 hepatoblastoma cells from FFA-triggered CD95/Fas up-regulation and apoptosis.

RESULTS

Patients [HCV clades 1 (78%), 2 (3%) and 3 (19%)] revealed increased FFA and adiponectin serum levels (p = .005). Hepatocyte CD95/Fas up-regulation correlated with steatosis, inflammation and fibrosis (p = .004). Advanced fibrosis correlated significantly (p = .05) with serum M30. Liver adiponectin correlated with steatosis (p = .016), CD95/Fas (p < .001) and inflammation/fibrosis. Hepatocyte AdipoR2 mRNA specifically correlated with serum adiponectin and steatosis (p = .003), while hepatocyte AdipoR1 mRNA dropped in pronounced fibrosis (p = .060). Finally, adiponectin protected HepG2 cells from FFA-triggered CD95/Fas expression and induction of apoptosis (p = .0396).

CONCLUSIONS

In chronic HCV infection, steatosis up-regulates hepatocyte CD95/Fas and thus increases apoptosis, which facilitates inflammation and fibrosis. The physiologic countermeasure of adiponectin up-regulation may offer clues for future therapeutic intervention.

MicroRNA gene expression profile of hepatitis C virus-associated hepatocellular carcinoma

MicroRNAs are small noncoding RNAs that regulate gene expression by targeting messenger RNAs (mRNAs) through translational repression or RNA degradation. Many fundamental biological processes are modulated by microRNAs, and an important role for microRNAs in carcinogenesis is emerging. Because understanding the pathogenesis of viral-associated hepatocellular carcinomas is important in developing effective means of classification, prognosis, and therapy, we examined the microRNA expression profiles in a large set of 52 human primary liver tumors consisting of premalignant dysplastic liver nodules and hepatocellular carcinomas by quantitative real-time polymerase chain reaction. All patients were infected with hepatitis C, and most had liver cirrhosis. Initially, the accessibility of microRNAs from formalin-fixed paraffin-embedded archival liver tissue by real-time polymerase chain reaction assays was shown. Subsequently, target parenchyma from routinely processed tissue was macrodissected, RNA was extracted, and reverse transcription followed by quantitative real-time polymerase chain reaction was performed. Relative quantification was performed by the 2(-DeltaDeltaCt) method with normal livers as a calibrator. In order to obtain a comprehensive microRNA gene expression profile, 80 microRNAs were examined in a subset of tumors, which yielded 10 up-regulated and 19 down-regulated microRNAs compared to normal liver. Subsequently, five microRNAs (miR-122, miR-100, miR-10a, miR-198, and miR-145) were selected on the basis of the initial results and further examined in an extended tumor sample set of 43 hepatocellular carcinomas and 9 dysplastic nodules. miR-122, miR-100, and miR-10a were overexpressed whereas miR-198 and miR-145 were up to 5-fold down-regulated in hepatic tumors compared to normal liver parenchyma.

CONCLUSION

A subset of microRNAs are aberrantly expressed in primary liver tumors, serving both as putative tumor suppressors and as oncogenic regulators.

Tissue hepatitis C virus RNA quantification and protein expression help identify early hepatitis C virus recurrence after liver transplantation

We compared tissue hepatitis C virus (HCV) RNA polymerase chain reaction quantification and HCV immunohistochemistry (IHC) to histology in biopsy tissues in order to differentiate between acute rejection and HCV hepatitis recurrence early after orthotopic liver transplantation (OLT). We analyzed the first biopsy performed because of alteration of serum aminotransferases in 65 consecutive OLT patients with HCV genotype 1b. In the histological analysis, we quantified the portal tracts, Councilman bodies, Councilman body/portal tract (CP) ratio, steatosis, and Knodell and Ishak scores. The 52 patients (80%) with histological HCV recurrence [recurrence-positive (Rec+)] were separated from the 6 (9%) with acute rejection and the 7 (11%) with undetermined pathological features [recurrence-negative (Rec-)]. HCV RNA strongly correlated with HCV IHC, regardless of the histological diagnosis (P < 0.001). Both HCV RNA and HCV IHC were significantly associated with CP ratio (P = 0.041 and P = 0.008). No statistical correlation was found between HCV RNA, HCV IHC, and the other histopathologic features or the hepatitis scores. HCV RNA, HCV IHC, and CP ratio were the only variables able to discriminate between Rec+ and Rec- patients (Mann-Whitney test P < 0.001, P < 0.001, P = 0.014). In conclusion, a combined evaluation of histology, tissue HCV RNA, and HCV IHC significantly discriminated between OLT patients with or without HCV recurrence.

Etiology-dependent molecular mechanisms in human hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and is characterized by aggressive tumor behavior coupled with poor prognosis. Various etiologies have been linked to HCC development, most prominently chronic hepatitis B and C virus infections as well as chronic alcohol consumption. In approximately 10% of HCCs, the etiology remains cryptic; however, recent epidemiological data suggest that most of these cryptogenic HCCs develop due to nonalcoholic steatohepatitis. To identify etiology-dependent DNA copy number aberrations and genes relevant to hepatocarcinogenesis, we performed array-based comparative genomic hybridization of 63 HCCs of well-defined etiology and 4 HCC cell lines followed by gene expression profiling and functional analyses of candidate genes. For a 10-megabase chromosome region on 8q24, we observed etiology-dependent copy number gains and MYC overexpression in viral and alcohol-related HCCs, resulting in up-regulation of MYC target genes. Cryptogenic HCCs showed neither 8q24 gains, nor MYC overexpression, nor target gene activation, suggesting that tumors of this etiology develop by way of a distinct MYC-independent pathomechanism. Furthermore, we detected several etiology-independent small chromosome aberrations, including amplification of MDM4 on 1q32.1 and frequent gains of EEF1A2 on 20q13.33. Both genes were overexpressed in approximately half the HCCs examined, and gene silencing reduced cell viability as well as proliferation and increased apoptosis rates in HCC cell lines.

CONCLUSION

Our findings suggest that MDM4 and EEF1A2 act as etiology-independent oncogenes in a significant percentage of HCCs.

Serum immunoglobulin G antibodies to the GOR autoepitope are present in patients with occult hepatitis C virus (HCV) infection despite lack of HCV-specific antibodies

Antibody responses to the GOR autoepitope are frequently detected among anti-hepatitis C virus (anti-HCV)-positive patients with chronic hepatitis. Sera from 110 anti-HCV-negative patients with occult HCV infection, as diagnosed by detection of HCV RNA in hepatic tissue, were investigated for GOR antibody reactivity. A positive test for anti-GOR immunoglobulin G (IgG) was found for 22 (20%) of them. The frequency and titers of anti-GOR IgG were significantly lower than those in chronic hepatitis C patients (70/110, 63.6%; P < 0.001). Anti-GOR IgG was not detected in any of the 120 patients with HCV-unrelated liver disease. The anti-GOR IgG assay showed specificity and sensitivity values of 100% and 20%, respectively, among the sera from patients with occult HCV infection; the positive and negative predictive values were 100% and 44.3%, respectively. None of the clinical, laboratory, or histological characteristics of the patients with occult HCV infection were different according to GOR antibody status, except that the percentage of HCV RNA-positive hepatocytes was significantly greater (P = 0.042) in patients with occult HCV infection who tested positive for anti-GOR IgG. In conclusion, serum anti-GOR IgG is present in patients with occult HCV infection, despite a lack of detectable HCV-specific antibodies as determined by commercial tests. Testing for anti-GOR IgG in patients in whom HCV RNA is not detected in their sera may help with the identification of a subset of patients with occult HCV infection without the need to perform a liver biopsy.

Fulminant central nervous system demyelination associated with interferon-α therapy and hepatitis C virus infection

Hepatitis C virus (HCV) infection is common in the general population and may coincide with disease in the central and peripheral nervous system. Interferon-α (IFN-α) is used as treatment for HCV infection. The therapeutic benefit is assumed to result from activation of natural killer cells and CD8+ T cells. Despite its beneficial effects, it has been associated with a number of autoimmune disorders, such as chronic inflammatory demyelinating polyneuropathy and multiple sclerosis. Several clinical reports including magnetic resonance imaging exist, but neuropathological confirmation of MS associated with IFN-α therapy and HCV infection is lacking. We report a case of a female patient with chronic HCV infection who developed `acute MS'-like demyelinating disease after IFN-α administration, with extensive lesions throughout brain and thoracic spinal cord. The patient died after a disease duration of 6 months. Brain autopsy revealed Baló-like demyelinating plaques with positive HCV sequences within florid lesions. The development of fulminant demyelinating disease after administration of IFN-α suggests that autoimmune mechanisms such as T cell mediated tissue damage might be initiated or aggravated by IFN-α therapy. Additionally, the presence of HCV RNA within the demyelinated lesion indicates a possible role in triggering or propagating disease. Multiple Sclerosis 2007; 13: 1100—1106. http://msj.sagepub.com

Nucleoporin 88 expression in hepatitis B and C virus-related liver diseases

AIM: To investigate the expression of nucleoporin 88 (Nup88) in hepatitis B virus (HBV) and C virus (HCV)-related liver diseases.

METHODS: We generated a new monoclonal Nup88 antibody to investigate the Nup88 protein expression by immunohistochemistry (IHC) in 294 paraffin-embedded liver specimens comprising all stages of hepatocellular carcinogenesis. In addition, in cell culture experiments HBV-positive (HepG2.2.15 and HB611) and HBV-negative (HepG2) hepatoma cell lines were tested for the Nup88 expression by Western-immunoblotting to test data obtained by IHC.

RESULTS: Specific Nup88 expression was found in chronic HCV hepatitis and unspecific chronic hepatitis, whereas no or very weak Nup88 expression was detected in normal liver. The Nup88 expression was markedly reduced or missing in mild chronic HBV infection and inversely correlated with HBcAg expression. Irrespective of the HBV- or HCV-status, increasing Nup88 expression was observed in cirrhosis and dysplastic nodules, and Nup88 was highly expressed in hepatocellular carcinomas. The intensity of Nup88 expression significantly increased during carcinogenesis (P < 0.0001) and correlated with dedifferentiation (P < 0.0001). Interestingly, Nup88 protein expression was significantly downregulated in HBV-positive HepG2.2.15 (P < 0.002) and HB611 (P < 0.001) cell lines as compared to HBV-negative HepG2 cells.

CONCLUSION: Based on our immunohistochemical data, HBV and HCV are unlikely to influence the expression of Nup88 in cirrhotic and neoplastic liver tissue, but point to an interaction of HBV with the nuclear pore in chronic hepatitis. The expression of Nup88 in nonneoplastic liver tissue might reflect enhanced metabolic activity of the liver tissue. Our data strongly indicate a dichotomous role for Nup88 in non-neoplastic and neoplastic conditions of the liver.

Efficient hepatitis C antigen immunohistological staining in sections of normal, cirrhotic and tumoral liver using a new monoclonal antibody directed against serum-derived HCV E2 glycoproteins

Detection and localization of Hepatitis C Virus (HCV) in liver tissue is useful for diagnostic purposes as well as to elucidate the mechanisms by which the virus participates in hepatocarcinogenesis. However, so far, a sensitive method for HCV detection at the cellular level is lacking. We describe here the application of a novel antibody, D4.12.9, developed against serum-derived HCV RNA-positive particles, for the detection of E2 proteins by immunohistochemistry in fixed, archived specimens including liver biopsies of HCV-infected patients and surgical specimens of hepatocellular carcinoma. We demonstrate that D4.12.9 is a powerful tool for sensitive and specific detection of HCV, independently of viral genotype. This approach has applications to diagnosis as well as exploratory pathological studies.

HBV, HCV, and TTV detection by in situ polymerase chain reaction could reveal occult infection in hepatocellular carcinoma: comparison with blood markers

OBJECTIVE

To report a retrospective analysis on the presence of hepatitis B virus (HBV), hepatitis C virus (HCV), and transfusion transmitted virus (TTV) sequences in formalin fixed, paraffin embedded liver biopsies from eight patients with hepatocellular carcinoma, in comparison with blood markers.

METHODS

A direct in situ polymerase chain reaction (PCR) technique was developed for the detection and localisation of genomic signals in the liver tissue. Conventional serological and molecular methods were used for blood evaluation.

RESULTS

In situ PCR showed the presence of one of the three viruses (four HCV, two HBV, and one TTV) in seven of the eight patients. In addition, a co-infection with HBV and HCV was detected in one patient. HCV and HBV sequences were located in the cytoplasm and the nucleus, respectively. When compared with blood markers, these findings were compatible with one occult HBV and two occult HCV infections.

CONCLUSIONS

These findings provide further evidence for occult HBV and HCV infections in cancerous tissues from patients with hepatocellular carcinomas. In situ PCR could be an additional tool for evaluating the viral aetiology of hepatocellular carcinoma alongside conventional diagnostic procedures.

Identification of novel HCV subgenome replicating persistently in chronic active hepatitis C patients

In an effort to clarify the life cycle of HCV, the HCV genome in liver biopsies taken from chronic active hepatitis C patients undergoing interferon treatment was investigated. Molecular cloning by long distance reverse-transcription polymerase chain reaction (RT-PCR) revealed that the HCV genome in two patients with high viral loads in the liver had in-frame deletions of approximately 2 kb between E1 and NS2, which encode the E1-NS2 fusion protein and six other HCV proteins: core, NS3, NS4A, NS4B, NS5A, and NS5B. Among the remaining 21 chronic active hepatitis C patients, these types of deletion were found in another two patients and in two hepatocellular carcinoma patients. Out-of-frame deletions in the structural region were isolated from the other five patients, but the dominant RT-PCR products were non-truncated genomes. Retrospective analysis of a series of serum samples taken from a patient carrying the subgenome with the in-frame deletion revealed that both the subgenome and the full genome persisted through the 2-year period of investigation, with the subgenome being predominant during this period. Sequence analysis of the isolated cDNA suggested that both the subgenome and the full genome evolved independently. Western blotting analysis of HCV proteins from the HCV subgenome indicated that they were processed in the same way as those from the full genome. HCV subgenomes thus appear to be involved in the HCV life cycle.

Comparison of transcription mediated amplification (TMA) and reverse transcription polymerase chain reaction (RT-PCR) for detection of hepatitis C virus RNA in liver tissue

BACKGROUND

Transcription mediated amplification (TMA) is known to be one of the most sensitive detection assays for hepatitis C virus (HCV) RNA in serum but has not yet been evaluated in liver tissue. It is unknown whether the higher sensitivity of TMA in comparison with polymerase chain reaction (PCR)-based assays is related to a higher efficiency of the extraction and/or amplification step.

OBJECTIVES

The sensitivity of a TMA-based assay (Versant HCV RNA Qualitative assay, Bayer Diagnostics) and a standard RT-PCR-based assay (Cobas Amplicor HCV 2.0, Roche Diagnostics) was compared in formalin-fixed paraffin-embedded liver biopsy specimens of patients with chronic hepatitis C.

STUDY DESIGN

After deparaffinization of 7.5 microm liver sections HCV RNA was extracted by standard phenol/chloroform. HCV RNA dilution panels were transferred in parallel to cDNA synthesis and amplification steps of PCR and TMA. Furthermore, TMA amplification from stepwise diluted HCV sera was performed following RNA extraction by either microcentrifuge colums (QIAmp Viral RNA spin Kit, Qiagen, Hilden, Germany) or magnetic microparticles (VERSANT HCV RNA Qualitative assay).

RESULTS

The total number of HCV RNA positive liver specimens detected by TMA was higher compared with those detected by RT-PCR (P=0.032). The total number of TMA positive serum samples was higher when HCV RNA was extracted using magnetic microparticles in comparison with multicentrifuge column extraction (P=0.019).

CONCLUSION

Our results suggest that both the extraction and amplification step of the TMA-based assay contribute to the higher sensitivity compared with standard RT-PCR.

Intracellular localization of NS3 and C proteins in chronic hepatitis C

AIMS AND METHODS

The cellular localization of hepatitis C virus (HCV) proteins in chronic hepatitis C remains a debatable issue. Aim of the studies included cellular and subcellular localization of two HCV proteins, NS3 and C protein, in liver biopsies from 20 children with chronic hepatitis C employing commercially available monoclonal antibodies and a semiquantitative technique of the proteins expression. In the studies advantage was taken of (Strept)avidin-biotin peroxidase complex and ImmunoMax technique.

RESULTS

The cytoplasmic localization of both proteins dominated over nuclear localization. The total amount of NS3 protein exceeded that of C protein. At the ultrastructural level, we observed both proteins in endoplasmic reticulum membranes and mitochondria, but small amount of both proteins was seen also in cell nuclei. The amount of either protein did not correlate with liver histology in our patients. No correlation could be disclosed between content of both proteins and HCV RNA levels in serum. Content of NS3 demonstrated negative correlation with activity of alanine transaminase.

CONCLUSION

In conclusion, the new aspect in present studies involved localization of C and NS3 proteins at the levels of light and electron microscopy in children. For the first time also intramitochondrial localization of NS3 protein was demonstrated.

Immunohistochemical identification of HCV target antigen in paraffin-embedded liver tissue: reproducibility and staining patterns

BACKGROUND

Immunohistochemical staining has been applied successfully to detect hepatitis C virus (HCV) antigen in fresh frozen tissue. In paraffin-embedded tissues, however, minimal trials with conflicting results have been reported.

AIMS

The present study is a trial to evaluate the identification of HCV antigen in paraffin-embedded liver biopsies using the anti-HCV monoclonal antibody (MAb) TORDJI-22.

METHODS

We applied immunohistochemical staining for HCV in 56 paraffin-embedded liver biopsy specimens, 46 from patients seropositive for HCV-RNA and 10 control liver biopsy specimens. The TORDJI-22 MAb was applied in dilution 1:40, with overnight incubation.

RESULTS

Reproducible staining patterns of HCV antigen in tissues were identified among the majority (42/46-91%) of HCV RNA seropositive cases. The staining pattern was cytoplasmic of hepatocytes, with occasional nuclear hue. It is mainly coarse granular with microvesicular pattern. Three staining patterns were identified: A, diffuse or membranous; B, patchy; and C, occasional paranuclear. None of the control samples showed a similar staining pattern.

CONCLUSION

Immunohistochemical identification of HCV antigen is easy to apply in paraffin-embedded liver biopsy specimens when the optimal detection techniques are applied. The staining pattern is reproducible, being mainly coarse granular cytoplasmic. Cross reactivity with hepatitis B virus antigens was not detected.

Long-term clinical and virological outcomes of chronic hepatitis C after successful interferon therapy

Clinical relevance of occult hepatitis C virus (HCV) and/or hepatitis B virus (HBV) infection(s) remains uncertain years after interferon (IFN) therapy for chronic hepatitis C. By 1993, 38 sustained virological responders (SVRs) showing HCV RNA clearance at 6 months post-treatment and 37 biochemical responders (BRs) with end-of-treatment alanine aminotransferase (ALT) normalization and subsequent 6-month stabilization within 2 x the upper limit of normal (ULN) were enrolled. They were monitored for 4.4-12 years (median 6.8), then 15 SVRs and 15 BRs underwent paired liver biopsies. Biopsy samples were tested for positive and negative HCV RNA strands, and HBV DNA surface and X sequences. All SVRs showed sustained serum HCV RNA clearance during follow-up, but hepatocellular carcinoma (HCC) developed in 4 (11%) SVRs. On paired liver biopsies, histological improvement was significant, but mild inflammation persisted in 87% of SVRs. Nonetheless, no HCV RNA sequence was amplified from liver tissues, and HBV DNA sequences were found in only one SVR. As for BRs, biochemical flare-up of >2 x ULN occurred at a 5-year risk of 41% (95% CI 24.7-56.4). The event was unpredictable but controllable by retreatment in 70%. Liver tissues after follow-up contained positive and negative HCV RNA strands, but no HBV DNA sequence was amplified. These results suggest that SVRs, albeit free of occult HCV and/or HBV infection(s) over a decade, retain mild liver inflammation and the risk of HCC. Occult HBV was also shown uninvolved in flare-up during follow-up of BRs.

Hepatitis C pathogenesis: mechanisms of viral clearance and liver injury

1. The development of hepatitis C virus (HCV) quasispecies has a number of biological consequences, including the development of escape mutants to humoral or cellular immunity, the generation of "defective" viral particles, variable cell tropism, and the development of drug resistance. 2. Accumulating evidence shows that HCV affects the early innate immune response mediated by natural killer and dendritic cells. 3. Recent data suggest that clearance of HCV bestows antibody to HCV immunity that affords partial protection against persistent infection. However, after spontaneous recovery from HCV infection, titers of HCV-specific antibodies decline and disappear in a subset of patients, whereas viral-specific CD4(+) and CD8(+) T-cell responses persist for decades. 4. HCV-specific CD8(+) T-cell responses are phenotypically and functionally diverse and may be associated with either viral eradication or chronic hepatic immunopathologic states. 5. Novel HCV genome-wide screening approaches have shown that the breadth of the immune response is considerably greater than was initially appreciated using more conventional assays, but why the majority of patients remain chronically infected despite the presence of viral-specific immune responses remains undefined.

Use of discriminatory probes for strain typing of formalin-fixed, rabies virus-infected tissues by in situ hybridization

An in situ hybridization (ISH) method has been developed to overcome difficulties encountered in the viral typing of formalin-fixed rabies virus-infected brain tissue. Rabies viruses representative of all strains normally encountered in diagnostic submissions throughout Canada, including 3 strains of terrestrial hosts (arctic fox, western skunk, mid-Atlantic raccoon), 10 strains circulating in several bat reservoirs (BBCAN1 to BBCAN7, LACAN, SHCAN, and MYCAN), and the Evelyn-Rokitniki-Abelseth (ERA) strain, used as an oral vaccine for fox rabies control in Ontario, were targeted. Partial phosphoprotein gene fragments generated from reverse transcription (RT)-PCR products of specimens of each viral type were molecularly cloned and used to produce negative-sense digoxigenin-labeled RNA transcripts. Conditions permitting the use of these transcripts as strain-specific probes were optimized by blotting analyses with RT-PCR amplicons generated with representative rabies viruses and by ISH applied to mouse brains inoculated with these strains. The successful application of this methodology to two rabies virus-positive specimens that were also identified by traditional methods and the retrospective typing of two archival rabies virus-positive equine specimens is described. This technique provides a typing regimen for rabies virus isolates submitted in a form that is normally recalcitrant to alternate typing strategies.

Ribavirin and interferon is effective for hepatitis C virus clearance in hepatitis B and C dually infected patients

Ribavirin and interferon (IFN) are an effective treatment in 30% to 60% of patients with chronic hepatitis C. Whether they are also effective in dually infected patients with hepatitis B and C is unknown. Twenty-four patients with chronic hepatitis seropositive for both hepatitis B surface antigen and antibody to HCV received ribavirin 1,200 mg daily for 6 months, together with 6 million units (MU) IFN-alpha 2a thrice weekly for 12 weeks and then 3 MU for another 12 weeks. Serum HCV RNA was positive in 21 patients (group I, serum HBV DNA positive in 17 patients) and negative in 3 patients (group II, all HBV DNA positive) by Amplicor (Cobas Amplicor Monitor, Roche Diagnostics, Branchburg, NJ). Serum alanine aminotransferase (ALT), HCV RNA, and hepatitis B virus (HBV) DNA were monitored regularly for 12 months. Another 30 patients with chronic hepatitis C alone receiving the same regimen, served as controls. The serum HCV clearance rate in group I patients (43%) was comparable with that in controls (60%, P =.63) 24 weeks posttreatment. The serum ALT normalization rate in group I and group II patients was 43% and 0%, respectively, 24 weeks posttreatment. After treatment, resurgence of HBV and HCV was encountered in 4 group I patients and 1 group II patient, respectively. In conclusion, in hepatitis B and C dually infected patients, combination of IFN with ribavirin can achieve a sustained HCV clearance rate comparable with hepatitis C alone. In dually infected patients, the treatment may alter the dominant, ruling hepatitis virus.

Histological improvement of chronic liver disease after spontaneous serum hepatitis C virus clearance

The long-term histological and virological outcomes of spontaneous circulating hepatitis C virus (HCV) clearance were studied in chronic liver disease. Between 1979 and 1984, three patients underwent laparoscopy for chronic non-A, non-B liver disease, and two were found to have cirrhosis and one with chronic active hepatitis. After HCV assays became available in 1990, they were positive persistently for HCV antibody without serum HCV RNA. Reductions of antibody levels to HCV core and/or nonstructural proteins were observed, and liver biopsies were undertaken between 1995 and 2000. Liver biopsies at 11-19 years after laparoscopy disclosed marked alleviation of liver inflammation and fibrosis in each case although a low grade of inflammation remained. The two patients with cirrhosis no longer showed histological features of cirrhosis, and the poor liver function in one patient had been ameliorated. Liver specimens from two patients were subjected to polymerase chain reaction to detect positive and negative HCV RNA strands and hepatitis B virus DNA. Only the positive HCV RNA strand was detected for one patient who had previously cirrhosis. Liver specimens were examined from another six nonviremic HCV-seropositive individuals without chronic liver disease. Five patients displayed low-grade liver inflammation without evident fibrosis, but none had any viral genome in the liver. These findings suggest that spontaneous circulating HCV clearance in chronic liver disease confers favorable liver histological outcome, although occult HCV infection persists. J. Med. Virol. 69:41-49, 2003.

Use of versant TMA and bDNA 3.0 assays to detect and quantify hepatitis C virus in semen

Previous findings of hepatitis C virus (HCV) in human semen have been inconsistent. This study attempted to elucidate the presence of HCV in semen from 80 HCV RNA blood plasma positive homeless men using two novel non-PCR based techniques. Semen was frozen immediately upon ejaculation in order to preserve virus quantity. This study demonstrated that 36% of the study population had HCV in semen. Bayer's Versant HCV RNA Qualitative Assay (Bayer Diagnostics, Emeryville, CA) based on transcription mediated amplification (TMA) assay detected 29 positive semen samples and Versant HCV RNA 3.0 Assay (bDNA) (Bayer Diagnostics, Emeryville, CA) detected only six. This demonstrated that TMA was more sensitive than the bDNA in detecting HCV in semen (P<0.002). HCV blood plasma viral load was positively correlated with the presence of HCV in semen (Spearman's Rho=0.40, P<0.0002), while the presence of leukocytes in semen was not (Spearman's Rho=0.19, P<0.12). This supports the hypothesis that HCV is "leaked out" from the peripheral circulation into semen. Three semen samples had a viral load of >5000 IU/mL. The presence of a high viral load in semen in certain men suggests that sexual transmission of the virus is possible. Laboratory capability to accurately detect HCV positive semen is an important step in establishing the risk of sexual transmission and in identifying strategies for protecting uninfected partners.

Peginterferon alone or with ribavirin enhances HCV-specific CD4 T-helper 1 responses in patients with chronic hepatitis C

BACKGROUND & AIMS

Pegylated interferons (IFNs) with or without ribavirin were shown in several studies to improve sustained virologic response compared with standard IFN alpha-2 therapy. This study investigated if the greater efficacy of pegylated IFNs might be related to modulation of immunologic responses.

METHODS

Hepatitis C virus (HCV)-specific CD4+ T-cell responses and cytokine production to various HCV proteins (Elispot assay) in peripheral blood were prospectively assessed in 42 patients receiving IFN alpha-2a monotherapy, peginterferon (PEG IFN) alpha-2a monotherapy, or PEG IFN alpha-2a plus ribavirin and correlated to the outcome of therapy.

RESULTS

The sustained virologic response rate was significantly higher in the PEG IFN groups (42% in PEG IFN alpha-2a monotherapy and 57% in PEG IFN alpha-2a/ribavirin combination) than in the standard IFN alpha-2a group (14%). The sustained response was 48% in HCV genotype 1 patients treated with PEG IFN alpha-2a/ribavirin therapy. Pretreatment HCV-specific CD4+ responses were either weak or absent. PEG IFN alone or combined with ribavirin induced significant increase in the frequency, strength, and breadth of HCV-specific CD4+ T-cell responses with type 1 predominance; whereas interferon alpha-2a monotherapy was associated with lower, fluctuating, short-lived responses. Sustained responders maintained multispecific HCV-specific CD4+ T-cell responses with enhanced IFN-gamma production. Relapsers and partial responders initially displayed significant HCV-specific CD4+ T-cell responses that waned or were lost.

CONCLUSIONS

The efficacy of PEG IFN alpha-2a alone or in combination with ribavirin in inducing high rates of sustained virologic response may be owing to the higher efficacy of PEG IFN in induction and maintenance of significant multispecific HCV-specific CD4+ T-helper 1 responses.

Intrahepatic HCV RNA loads in 37 HIV-HCV co-infected patients with controlled HIV infection

Serum and intrahepatic hepatitis C virus (HCV) RNA were measured in 37 HIV-HCV co-infected patients with controlled human immunodeficiency virus (HIV) infection and correlated with clinical, biological, and histological parameters. Thirty-seven interferon-naive patients underwent liver biopsy. HCV-induced activity (A) and fibrosis (F) were evaluated with METAVIR score. The 37 patients included had HIV plasma loads < 10,000 copies/ml, CD4(+) count > 250/microl. All the patients but two were receiving antiretroviral treatment. Liver tissue and sera were used for measurement of HCV RNA by the Cobas Amplicor HCV Monitor. All patients had serum and liver HCV RNA, and both levels were correlated (r = 0.47; P = 0.003). Intrahepatic HCV load did not depend on age, sex, duration of HCV infection, CD4(+), HCV genotype, or fibrosis. AST levels correlated with intrahepatic HCV load (r = 0.52; P = 0.001). Patients with METAVIR A1/A2 had significantly lower levels of liver HCV-RNA than were found in patients with METAVIR A3 (P = 0.026). Highly active antiretroviral therapy (HAART) including protease inhibitors(PI)-treated patients had significantly lower intrahepatic HCV load (P = 0.04). A weak but significant correlation between serum and liver HCV RNA was found. The amount of hepatic HCV RNA was correlated with AST levels, histological activity, but not with HCV genotype or fibrosis. The immune improvement associated with PI regimens could help reduce HCV load, supporting a protective effect of PI-induced immune restoration.

Frequencies of HCV-specific effector CD4+ T cells by flow cytometry: correlation with clinical disease stages

Hepatitis C virus (HCV) is the leading cause of chronic hepatitis, affecting approximately 2% of the world's population. The immune mechanisms responsible for the highly variable natural history in a given individual are unknown. We used a multiparameter flow cytometric technique to functionally and phenotypically characterize HCV-specific effector T cells in the peripheral blood of 32 individuals with different stages of hepatitis C disease (resolved, mild chronic, advanced chronic) and normal controls. We found the highest frequencies of virus-specific effector cells with an activated memory phenotype (CD45RO+CD69+) in subjects who had resolved HCV infection, either spontaneously or with antiviral therapy. Effector cells from patients with resolved infection produced Th1 type cytokines following stimulation with nonstructural antigens (NS3 and NS4), whereas effector cells from chronically infected patients produced Th1 type cytokines predominantly following stimulation with the HCV core antigen. Stimulation with superantigen staphylococcal enterotoxin (SEB) induced the same levels of cytokine production in the different patient groups. Among the HCV-seropositive patients, viral load inversely correlated with the Th1 effector cell response to NS3. Interleukin (IL)-4 was produced only in response to the control antigens, but not in response to the HCV recombinant proteins. Taken together, these findings suggest that a vigorous HCV-specific CD4+ Th1 response, particularly against the nonstructural proteins of the virus, may be associated with viral clearance and protection from disease progression. Prospective studies using this new flow cytometric assay will be required to determine whether antiviral therapy modifies the frequency, specificity, and function of these virus-specific effector cells.

Hepatitis C virus infection of human hepatoma cell line 7721 in vitro

AIM: To establish a cell culture system with long-term replication of hepatitis C virus in vitro.

METHODS: Human hepatoma cell line 7721 was tested for its susceptibility to HCV by incubating with a serum from a patient with chronic hepatitis C. Cells and supernatant were harvested at various phases during the culturing periods. The presence of HCV RNA, the expression of HCV antigens in cells and/or supernatant were examined by RT-PCR, in situ hybridization and immunohisto-chemistry respectively.

RESULTS: The intracellular HCV RNA was first detected on d2 after infection and then could be intermittently detected in both cells and supernatant over a period of at least three months. The expression of HCV NS₃, CP₁₀ antigens could be observed in cells. The fresh cells could be infected by supernatant from cultured infected cells and the transmission of viral genome from HCV-infected 7721 cells to PBMCs was also observed.

CONCLUSION: The hepatoma line 7721 is not only susceptible to HCV but also supports its long-term replication in vitro.

Immunohistochemical detection of hcv in cirrhosis, dysplastic nodules, and hepatocellular carcinomas with parallel-tissue quantitative RT-PCR

Hepatitis C virus is a major risk factor for hepatocarcinogenesis in humans. In situ detection of the virus in early sequential lesions of hepatocarcinogenesis could provide information about the role of the virus in the transformation and promotion process. Parallel in situ detection of HCV proteins and RNA in human tissues were performed in 55 posthepatitis C cirrhosis, 17 dysplastic nodules (DN), and 25 hepatocellular carcinomas (HCC), using immunohistochemistry and tissue quantitative RT-PCR. A consistent cytoplasmic hepatocellular staining was obtained in 73% of cirrhosis cases (with or without HCC) and in 55% DN cases. A few tumoral hepatocytes were unambiguously stained in 28% HCC. The percentage of positive cells and the intensity of immunostaining significantly decreased from cirrhosis to HCC through DN, whereas there was no difference in the prevalence of positivity or the number of viral copies between cirrhosis and HCC using tissue-quantitative RT-PCR. Finally, RT-PCR levels were found parallel with the immunostaining in cirrhosis but not in HCC. These results suggest that HCV protein synthesis may persist but be down-regulated during sequential hepatocarcinogenesis. A putative role of HCV proteins on cell proliferation and differentiation during the early steps of carcinogenesis cannot therefore be excluded.

Liver biopsy: when, how, by whom, and where?

Liver biopsy remains an important diagnostic tool in the management of liver disease. Complications, though infrequent, are potentially disastrous. Risks and discomfort can be minimized with good technique, although prospective data to prove the superiority of one method over another are often lacking. Image direction is preferred in all cases, as is a transjugular approach when bleeding risks are judged to be high. Bleeding is essentially a random event. Outpatient liver biopsy is appropriate in almost every instance if immediate hospitalization facilities are available. It should be more widely practiced. Liver biopsies should only be done if, after thoughtful assessment, benefits are thought to exceed risks.

Use of whole blood specimens for routine clinical quantitation of hepatitis C virus RNA does not increase assay sensitivity

The measurement of hepatitis C virus (HCV) RNA levels in the blood has, in the last few years, become a critical component in the therapy of patients with HCV infections. Initially, extraction methods for serum and plasma were used, but a newer method that uses Catrimox-14 as the extraction agent for whole blood has been reported. Because the whole blood extraction method may yield higher virus levels if significant levels of virus are present in the white blood cells (WBC), the method was evaluated for use in our clinical diagnostic laboratory despite its higher reagent costs and more time-consuming methodology. RNA was simultaneously extracted from 39 clinical samples by four different methods: Catrimox-14-Trizol extraction from whole blood, Trizol extraction from whole blood, Trizol extraction from serum, and a commercial serum extraction method, the EZNA total RNA kit. In addition, in an effort to quantitate the amount of HCV RNA virus in the WBC, Trizol extraction from isolated WBC was also performed. Quantitative results for samples from which RNA was extracted by all four methods were essentially the same; the Catrimox-14-Trizol method did not yield increased virus levels. Insignificant levels of virus were found in the WBC. The results did not demonstrate a clinical usefulness for the Catrimox-14-Trizol method.

Analysis of successful immune responses in persons infected with hepatitis C virus

Although hepatitis C virus (HCV) infection is very common, identification of patients during acute infection is rare. Consequently, little is known about the immune response during this critical stage of the disease. We analyzed the T lymphocyte response during and after acute resolving HCV infection in three persons, using interferon (IFN)-gamma enzyme-linked immunospot (ELISPOT) and human histocompatibility leukocyte antigen (HLA) peptide tetramer assays. Acute infection was associated with a broadly directed T helper and cytotoxic T lymphocyte (CTL) response, which persisted after resolution of clinical hepatitis and clearance of viremia. At the earliest time point studied, highly activated CTL populations were observed that temporarily failed to secrete IFN-gamma, a "stunned" phenotype, from which they recovered as viremia declined. In long-term HCV-seropositive persons, CTL responses were more common in persons who had cleared viremia compared with those with persistent viremia, although the frequencies of HCV-specific CTLs were lower than those found in persons during and after resolution of acute HCV infection. These studies demonstrate a strong and persistent CTL response in resolving acute HCV infection, and provide rationale to explore immune augmentation as a therapeutic intervention in chronic HCV infection.

Pathology of the liver

At the close of the 20th century, a selection of articles published in 1999 with relevance to liver pathology reflects the wealth of technological and intellectual progress made during the span of the century. Immunohistochemical staining for hepatitis B virus antigens focused attention on a correlation between cytoplasmic expression of core antigen in individuals with precore mutants and higher activity of hepatitis. Infection of ducklings with a presurface mutant strain of duck hepatitis B virus produced cytopathic liver cell damage. Fibrosing cholestatic hepatitis, originally described as an unusual form of recurrent hepatitis B after liver transplantation, has now been described in hepatitis C virus-positive patients with renal transplants. It may be related to the emergence or selection of hepatitis C virus quasispecies. In biliary tract disease, researchers investigated the canal of Hering as a possible source of hepatic stem cells, sporadic mutations in the JAGGED1 gene (involved in cell differentiation) in Alagille syndrome, and several models of nonsuppurative destructive cholangitis. Further work was accomplished on nonalcoholic steatohepatitis, including a proposal of a grading and staging system as well as its detection in workers exposed to volatile petrochemicals. Among hepatic neoplasms and proliferative disorders, epithelioid hemangioendothelioma, angiomyolipoma and Langerhans' cell histiocytosis received coverage in articles describing the diagnostic pathology in collected series of patients.

Methacarn fixation: a novel tool for analysis of gene expressions in paraffin-embedded tissue specimens

To establish a quantitative method for analysis of gene expressions in small areas of tissue after paraffin embedding, preliminary validation experiments with RT-PCR and Western blotting were performed using methacarn-fixed rodent tissues and a cultured PC12 cell line. A total RNA yield of 52 +/- 15 ng/mm2, sufficient for a quantitative RT-PCR of many genes, could be extracted from a deparaffinized 10-microm-thick rat-liver section by a simple, single-step extraction method. The low concentration of contaminating genomic DNA and the resolution of ribosomal RNAs in RNA gel proved the purity and integrity of the extracted RNA samples, allowing PCR amplification of a long mRNA sequence and mRNA species expressing low copy numbers. PCR amplification of mRNA-derived target gene fragments could be achieved by optimizing the amount of total RNA for reverse transcription and the number of subsequent PCR cycles for each gene. By this validation, organ- and sex-specific mRNA expression could be detected in methacarn-fixed paraffin-embedded tissues without additional DNase treatment of RNA samples. RT-PCR analysis could also be performed with total RNA extracted from deparaffinized tissue dissected with a laser capture microdissection system. In addition, extraction of protein yielded 4.9 +/- 2.1 microg/mm2 from a 10-microm-thick rat-liver section, allowing a quantitative expression analysis of protein by Western blotting. Thus, in addition to its advantages for immunohistochemistry, methacarn-fixed paraffin-embedded tissue has benefits for analysis of both RNAs and proteins in the cells of histologically defined areas.

Liver biopsy in hepatitis C

The advent of more specific and sensitive assays for the diagnosis of hepatitis C has provided better definition of the histopathology of this disease and its differentiation from other forms of hepatitis. The following features have been found to be characteristic but not pathognomonic: lymphoid follicles in the portal tracts, bile duct lesions, fatty metamorphosis and Mallory body-like condensations in the cytoplasm of the hepatocytes. It has been suggested that the virus genotype may be correlated with different histopathologies. A better understanding of chronic hepatitis C has led to a more flexible and accurate terminology of chronic hepatitis, including the grade of necroinflammatory activity and the stage of fibrosis. Both seem to be of prognostic value in the course of chronic hepatitis C. Recurrence of hepatitis C in the graft after liver transplantation may have a different histopathologic pattern with progressive fibrosis, conspicuous cholestasis and pronounced hepatocellular necrosis. Histopathology grade and stage of liver damage in chronic hepatitis C is not reflected by serum aminotransaminase level or serological status.

Long-term efficacy of treatment of chronic hepatitis C with alpha interferon or alpha interferon and ribavirin

The major objective of treatment of chronic hepatitis C virus (HCV) infection is to prevent progression to cirrhosis, and thereby prevent complications of end-stage liver disease. The established treatment of chronic HCV is with alpha interferon. Recent results with ribavirin and alpha interferon together suggest that combination antiviral therapy will become the benchmark treatment. For both naive and relapsed patients, however, it has become important to assess the long-term outcome of treatment, in order to gauge whether treatment has indeed modified the natural history of chronic hepatitis C virus infection. It seems likely that most sustained responders (85-90%) treated with combination ribavirin and alpha interferon will continue to have a long-term biochemical and virological response, as has been demonstrated with alpha interferon alone, but further long-term follow-up of patients treated with combination therapy is required.

Pathologic features of chronic hepatitis. A review and update

The general histopathologic changes of chronic hepatitis and those related to the various causes are reviewed. Consideration also is given to underlying or associated diseases and to mixed infections in chronic viral hepatitis. Changes occurring in exacerbations or relapses are described. Selected histopathologic changes are illustrated. The nomenclature is reviewed briefly, with emphasis on separation of activity from stage of disease.