Hepatitis B virus (HBV) infection is a major global health issue causing end-stage liver disease or hepatocellular carcinoma. Based on virus-host interactions, natural course of chronic hepatitis B (CHB) infection can be divided into four chronological phases.
Immune tolerant (IT) phase, the first phase of natural course of CHB, is defined as normal alanine aminotransferase (ALT) and very high level of HBV DNA according to the current international guidelines and is traditionally considered “benign” disease due to host's immune tolerance. However, evidences from basic and clinical studies argued that IT phase may not completely be a benign feature. Immunologic studies demonstrated that HBV-specific immune responses in patients with IT phase are as active as those in patients with immune clearance phase, which is indicated for antiviral treatment. In addition, recent large-scale observational studies also support this notion showing that higher and worse long-term clinical outcomes in patients with IT phase than patients with immune active phase under antiviral treatment. Therefore, issues of earlier antiviral treatment and treatment indication expansion beyond current treatment guidelines are currently under hot debate. Nevertheless, opinion deferring treatment for patients with IT phase still prevails given that possibility of spontaneous HBeAg seroclearance, poor response to current treatments in patients with IT phase, and expected good long-term clinical outcomes in patients with genuine IT phase. Evidences from prospective randomized trials warrant to re-determination of treatment indication.

Chronic hepatitis B virus (HBV) infection is the leading cause of chronic liver disease worldwide, and can lead to liver cirrhosis and hepatocellular carcinoma. The major route of transmission of HBV is perinatal transmission from mother to child. According to recent clinical trials and meta-analysis, benefit of antiviral therapy has confirmed for prevention of perinatal HBV transmission from mother to child when HBV DNA titer of mother is ≥200,000 IU/mL. However, there are also several concerns of antiviral therapy for maternal and fetal safety during perinatal period. This review will discuss the risks and benefits of antiviral therapy during pregnancy.

Hepatitis B virus (HBV) reactivation is characterized by the increase in HBV DNA in patients with chronic hepatitis B or reappearance of HBV particles in patients with previously resolved HBV. Reactivation is commonly triggered during immunosuppressive therapy. HBV reactivation can cause hepatitis flare resulting in liver failure and death. However, it is preventable if at-risk individuals are identified through screening and started on prophylactic antiviral therapy if indicated. In this review, we discuss definition of HBV reactivation, risk stratification of reactivation, and strategies for screening and prophylactic antiviral therapy during immunosuppressive therapy based on the current guidelines.

Since the introduction of direct-acting antiviral agents (DAA) for chronic hepatitis C, sustained virologic response rate has steeply elevated. Theoretically, effective antiviral treatment may pose a positive impact in the patients with hepatocellular carcinoma who had a curative treatment because virologic cure can result in the regression of fibrosis and improvement of portal hypertension. However, a few recent studies suggested the unexpected high HCC recurrence after DAA treatment, which induced a hot issue, and subsequent studies showed inconsistent results. Although considering the many limitations of available studies, there is no strong evidence of increased risk of HCC recurrence after DAA treatment right now. Therefore, at present, it is prudent to perform DAA treatment in the patients with curative treatment for HCC at the point that their complete response becomes more certain.

비알코올 지방간(nonalcoholic fatty liver disease)은 유의한 알코올 섭취 없이, 간조직 5% 이상에 지방이 축적되는 질환으로 인슐린 저항성 및 대사증후군과 밀접한 관계가 있다. 대사증후군은 공복 혈당의 이상, 2형 당뇨, 이상지질혈증, 고혈압 및 허리둘레 이상으로 이루어져 있는데 비알코올 지방간 환자에서 대사증후군의 요소 중 어떠한 이상이 있는 지 살펴봐야 한다. 또한 대사증후군은 심혈관질환과도 연관이 깊으며, 비알코올 지방간 환자의 사망 원인 중 간질환 자체보다 심혈관질환이 더 문제가 되었다는 보고도 있어서 이에 대한 평가와 적절한 치료가 필요하다.

To diagnose minimal hepatic encephalopathy is difficult due to asymptomatic feature and limitation in the use of psychometric or neurophysiologic tests at bedsides. However, patients suffer impaired quality of life, increased risks of job loss, fall, fractures, car accidents, and mortality. There are many established tests but norm-based, validated tools are limited and should be specialized to the region where the tests are applicated. In that sense, Korean paper pencil test and Korean stroop test can be used as diagnostic tools in Korea for screening and diagnosis of minimal hepatic encephalopathy. Animal naming test is simple but should be validated in Korea. Every test measures a bit different domains of the brain. Additionally, hepatic encephalopathy involves wide range of cognitive function. Therefore, using more than two different tools is recommended for the objective diagnosis of minimal hepatic encephalopathy.