Various scoring systems evaluating histologic features of chronic hepatitis C treated with interferon

Pathology of liver disease: advances in the last 50 years

Liver disease has been recognized in various forms for centuries. Incredible advances, however, have been made especially in the last 50 years, driven by improvements in histology, the development of immunostains, the development of high resolution imaging methods, improved biopsy and resection methods, and the emergence of the molecular era. With these tools, pathologists and their clinical and basic science colleagues moved from classifying liver disease using an observational, pattern-based approach to a refined classification of disease, one based on etiology for medical disease and tumor classification for neoplastic disease. Examples of liver specific diseases are used to illustrate these exciting advances. These impressive advances of the past provide the foundation for hope in the future, as liver pathology continues to play an important role in improving patient care through disease identification and classification and emerging roles in guiding therapy for cures.

Differences in sequences between HBV-relaxed circular DNA and covalently closed circular DNA

The hepatitis B virus (HBV) genome exists in two forms: circular covalently closed DNA (cccDNA) and relaxed circular DNA (RCDNA). Here, we investigated the presence of differences in the sequences of both forms in paired samples of serum and liver tissue. The serum and liver biopsy samples were collected at the same time from 67 chronically infected patients. The genotyping of the RCDNA and cccDNA was performed using mass spectrometry analysis. The HBV mutations located in the HBV pol (P) and the HBV basal core promoter/pre-core (BCP/PC) regions were included. The BCP/PC and P sequences of the RCDNA extracted from liver and blood samples were different in 39% and 16% of patients, respectively. Differences were also found between RCDNA and cccDNA extracted from the same liver specimen. Moreover, the cccDNA BCP/PC region sequence had an impact on various virological and clinical parameters. We demonstrated that there are differences between the RCDNA and cccDNA sequences that were extracted from the same liver tissue. However, further investigations are needed to analyze whether the mutations in the cccDNA are conserved and whether cccDNA serves as a ‘mutation storage’ pool for HBV. This result could have profound implications for the subsequent therapy choices for treatment-experienced patients.

Histopathological study of chronic hepatitis B and C: a comparison of two scoring systems

BACKGROUND/AIMS

Several histological scoring systems are used to evaluate chronic viral hepatitis. This study was undertaken to determine the correlation between the Ishak system (modified histological activity index, HAI) and the METAVIR system, in Indian patients with chronic viral hepatitis.

METHODS

Liver biopsies from 127 patients with chronic viral hepatitis B or C were examined, and scored using the Ishak and METAVIR systems, and weighted kappa analysis of correlation was done. Correlation of necroinflammatory activity with serum transaminase levels was analyzed, and prevalence of specific histological features compared in hepatitis B virus (HBV) and HCV biopsies.

RESULTS

HBV infection accounted for 64.6% of cases, and HCV for 35.4%; 91.3% of patients had minimal or mild hepatitis. The necroinflammatory scores of the Ishak and METAVIR systems correlated moderately well (weighted kappa 0.627), while there was excellent correlation with regard to fibrosis (weighted kappa 0.998). Similar concordance was found when HBV and HCV cases were analyzed separately. HAI showed poor correlation with serum transaminases (weighted kappa 0.21). Micronodular cirrhosis, lymphoid aggregates, bile duct damage, bile ductular proliferation and steatosis were significantly more common in HCV biopsies compared to HBV.

CONCLUSIONS

Concordance between Ishak and METAVIR scoring systems is good for necroinflammatory change, and excellent for fibrotic change.

Hepatobiliary pathology

Technologic advances using cDNA microarray hybridization, liver diseases characterized by mitochondrial DNA depletion, and new work characterizing bile salt transport problems in familial intrahepatic cholestasis syndromes were some of the major highlights of this past year. Analysis of normal livers by cDNA microarrays disclosed 2418 unique gene transcripts encoding a host of cellular structural and functional proteins. This technique was also applied to hepatocellular carcinoma, where enhanced expression of a number of genes involved in antiapoptosis and cell transformation may shed additional light on the process of hepatocarcinogenesis. Mitochondrial DNA depletion seen in Navajo neurohepatopathy and in respiratory chain disorders of infancy was associated with cholestasis and cirrhosis in the former and microvesicular steatosis and oncocytic transformation (mitochondrial hyperplasia) in the latter. Pathologists who routinely examine liver biopsies after liver or bone marrow transplantation should be aware of unusual biopsy features that mimic other diseases, such as the autoimmune hepatitis-like syndrome that may follow liver transplantation and chronic graft-versus-host disease that clinically and pathologically resembles acute hepatitis.