[Diagnosis and therapy of hepatitis B virus infection: Czech national guidelines]

The new recommendations reflect the increase in knowledge that has been reported since the release of previous Czech guidelines in September 2014. The basis for these guidelines were the European Association for the Study of the Liver guidelines from April 2017. According to qualified estimates, there are 240 million people with chronic hepatitis B (HBV) infection worldwide. The Czech Republic is among the countries with a low prevalence of HBV infection. According to the latest seroprevalence study, 0.56 % of the Czech citizens were chronically infected with HBV in 2001. A similar study conducted in only two regions of the Czech Republic in 2013 showed a prevalence of only 0.064 %. HBV infection can lead to serious life-threatening liver damage - fulminant hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC). The main goals of treatment are to prolong the length of life and improve its quality by preventing the progression of chronic hepatitis to cirrhosis, cirrhosis decompensation and development of HCC. The goals may be achieved if HBV replication is suppressed in a sustained manner. Additional goals are prevention of vertical transmission from mother to newborn, inhibition of HBV reactivation and therapy of HBV-related extrahepatic manifestations. Generally, there are two different strategies of chronic hepatitis B therapy available - treatment with nucleoside or nucleotide inhibitors (NIs) or with pegylated interferon alfa. Currently, the vast majority of Czech and European patients are treated with NIs. The NIs that have been approved for HBV treatment in the European Union include lamivudine, adefovir dipivoxil, entecavir (ETV), telbivudin (TBV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF). TAF and TBV have not yet been marketed in the Czech Republic. The main advantages of treatment with potent NIs with a high barrier to resistance (ETV, TDF, TAF) are their predictable high long-term antiviral efficacy leading to undetectable HBV DNA levels in the vast majority of compliant patients as well as their favorable safety profiles. These drugs can be used in any HBV infected patient and represent the only treatment option for patients with decompensated liver cirrhosis, liver transplants, extrahepatic HBV-related manifestations, severe acute hepatitis B or chronic HBV reactivation.

[Diagnosis and therapy of chronic hepatitis B: Czech national guidelines]

The new recommendations reflect the increase in knowledge that has been reported since the release of previous Czech guidelines in April 2009. According to qualified estimates, there are 350-400 million people with chronic hepatitis B (HBV) infection worldwide. The Czech Republic is among the countries with a low prevalence of HBV infection. According to the latest seroprevalent study, 0.56 % of the Czech citizens were chronically infected with HBV in 2001. HBV infection can lead to serious life-threatening liver damage - fulminant hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC). The goals of treatment are to prolong the length of life and improve its quality by preventing the progression of chronic hepatitis to cirrhosis, cirrhosis decompensation and development of HCC. The goals can be achieved if HBV replication is suppressed in a sustained manner. Then, the accompanying reduction in histological activity lowers the risk of cirrhosis and HCC, particularly in non-cirrhotic patients. Currently, two different strategies for treating chronic hepatitis B are available. Treatment of finite duration is with pegylated interferon (PEG-IFN), entecavir (ETV), or tenofovir (TDV). A 48-week course of PEG-IFN is mainly recommended for HBeAg-positive patients with the best chance of anti-HBe seroconversion. Finite-duration of ETV or TDV treatment is available for HBeAg-positive patients who seroconvert to anti-HBe on treatment. However, treatment duration is unpredictable prior to the therapy as it depends on the timing of anti-HBe seroconversion and the treatment continuation following anti-HBe seroconversion (therapy should be prolonged for additional 12 months after anti-HBe seroconversion). Long-term ETV or TDV therapy is necessary for HBeAg-positive patients who do not develop anti-HBe seroconversion and for HBeAg-negative patients. This strategy is also recommended for patients with cirrhosis irrespective of the initial HBeAg status or anti-HBe seroconversion on treatment. The advantage of ETV and TDV is based on their high potency and optimal resistance profile.

[Diagnosis and treatment of chronic hepatitis B. Recommendations of the Czech Hepatology Society of the J. E. Purkinje Medical Society and the Society of Infectious Medicine of the J.E. Purkinje Medical Society]

Chronic hepatitis B is one of the world's most common infectious diseases. In the Czech Republic it has a prevalence of 0.56%. Antiviral therapy for chronic hepatitis B demonstrably increases quality of life and where indication criteria are met and standard therapeutic procedures are followed, it is clearly cheaper than treatment for the complications of advanced cirrhosis of the liver or hepatocellular carcinoma. At the time of issuing of this recommendation, 4 medicines were classified for the treatment of chronic hepatitis B in the Czech Republic--pegylated interferon (IFN) alpha-2a, conventional IFN alpha, lamivudine (LAM) and adefovir dipivoxil (ADV). In a number of other developed states, entecavir (ETV) and telbivudine (LdT) have also been approved for treatment. The most effective treatment available at present is pegylated IFN alpha-2a, which should be the medication of first choice for initial treatment of hepatitis B, HBeAg positive and negative forms, provided that there are no contraindications for IFN alpha treatment. Conventional (standard, classical) IFN alpha can also be used, though clinical studies have shown it to be less effective than pegylated IFN alpha-2a. The main advantage of interferon compared to other commercially available medications is its relatively shorter and more clearly defined treatment period, the high probability of permanent suppression of virus replication and seroconversion of HBeAg/anti-HBe (in HBeAg positive forms of the illness) and the non-creation of mutant strains of HBV resistant to IFN in the course of treatment. If there are contraindications for IFN alpha (pegylated or conventional) or it is ineffective or poorly tolerated, ADV, ETV, LAM or LdT can be used. LAM and LdT treatments are often accompanied by the appearance of mutant strains of HBV, that are resistant to lamivudine or LdT and therefore they are not preferred.

[The role of STAT proteins in the regulation of the response to the interferone alpha therapy in chronic hepatitis C]

The currently used standard treatment for chronic hepatitis C using a dual combination of IFNalpha/RBV is only successful in 50% cases. With the exception of some clinical and biochemical factors, degree of inflammation (grading) and degree of fibrosis (staging), there are no other known markers which may serve as valid predictors of response to therapy. Interference of hepatitis C virus (HCV) with signaling pathways modulated by JAK-STAT, ERK 1/2, NFkappaB and MAP proteins is one mechanism which may influence the interaction between HCV and IFNalpha. These proteins regulate different cell processes such as activation of cytokines, activation of apoptosis, regulation of cell proliferation etc. Therefore, it is possible that impaired signaling or inhibition/dysregulation of some of these proteins by HCV infection may cause resistance to IFNalpha treatment. This review is completed by results of preliminary study the aim of which was immunohistochemical assessment and analysis of expression of STAT 2, 3 proteins, their inhibitors SOCS 2, 3 and PIAS 3 and proteins JAK 1 and ERK 1/2 in liver biopsies of 26 patients with chronic hepatitis C treated by dual combination IFNalpha/RBV and subsequent correlation of the results of immunohistochemical analysis (histoscore) with histological picture and clinical response to treatment. The results shows increased expression of STAT 3, STAT 2 and ERK 1 proteins and decreased expression of SOCS 3 and SOCS 2 in hepatocytes of patients with more marked inflammation and fibrosis. In patients with sustained virological response there was increased expression of SOCS 3 and JAK 1 and decreased expression of SOCS 2. Relapse was associated with increased expression of SOCS 3 and PIAS 3. However, owing to the small sample size, the results only approximated statistical significance, but we suggest that proteins of STAT family and their inhibitors SOCS and PIAS probably play an important regulatory role during response to treatment for chronic hepatitis C.