**Author details**

genes related to metabolism and immune responses. In hepatocellular carcinoma arising in hepatitis C patients, genes associated with cell cycle, growth, proliferation and apoptosis are up-regulated [69]. Chronic hepatitis B and autoimmune liver disease have been studied by this technology as well [70]. In advanced chronic viral hepatitis B, genes associated with ex‐ tracellular matrix turnover, cell growth and DNA repair are up-regulated but the expression of genes regulating complement activation and innate immune response is decreased. In early disease stages, the gene expression is different in case of chronic viral hepatitis B, auto‐ immune hepatitis and primary biliary cirrhosis. Chronic viral hepatitis B is associated with expression of genes considering chemotaxis and cell homeostasis; autoimmune hepatitis – with down-regulation of genes associated with protein binding, but primary biliary cirrhosis in early stages involves the actin and myosin gene expression. As chronic viral hepatitis B progresses, the expression of genes regarding signalling pathway, cell communication, col‐ lagen turnover, chemokine ligands and metallothionein changes [70]. The findings are of major interest displaying the pathogenesis of different inflammatory liver diseases and neo‐ plastic transformation. Diagnostic consequences should follow soon as the differential diag‐ nosis of inflammatory liver diseases regarding aetiology can represent a difficult task.

The level of mRNA can be post-transciptionally regulated by micro RNA (miRNA). The reg‐ ulation of biological processes by miRNA is shown also in case of such canonical diffuse liv‐ er disease as chronic viral hepatitis C. Technological studies have been conducted using biopsy material [71]. Transcriptome analysis has shown prognostic value, e.g., in order to predict the severity of fibrosis progression after liver transplantation in recurrent viral hepa‐

Liver biopsy investigation could soon shift from routine light microscopy to digital image analysis by virtual microscopy and incorporation of numerical measurements in conjunction with integrated analysis of cell functions at DNA, RNA, protein and signalling level. This shift could lead from static to dynamic tissue evaluation. The technological logistics should include the best standards of tissue fixation, processing, microtomy and visualisation com‐ plemented by automated immunostaining, full slide scanning to ensure complete digital analysis and optimal choice of software considering the biological appropriateness of the

As the diagnostic electron microscopy is continually developing, we expect that in future it will be used in hepatology as an auxiliary method, based on digital analysis of electrono‐ grams. Liver biopsy analysis using transmission and scanning electron microscope could continue to provide important additional information in diagnostic hepatology and scientif‐ ic research of liver diseases, as well as it could help to study unresolved molecular mecha‐ nisms regulating liver cells' functions. In future the ultrastructural studies of liver biopsy in hepatology will probably be associated with assessment of liver tissues in cases of liver transplantation, with studies of new medicinal products – detection or exclusion of their po‐

titis C patients [72].

272 Liver Biopsy – Indications, Procedures, Results

**8. Conclusions**

analysis algorithm.

Ludmila Viksna1,2, Ilze Strumfa1 , Boriss Strumfs3 , Valda Zalcmane1 , Andrejs Ivanovs1 and Valentina Sondore2

