画期的なウイルス肝炎の治療薬の登場とともに，本邦の肝硬変の原因は，アルコール，代謝機能障害関連脂肪肝炎（Metabolic Dysfunction-Associated Steatohepatitis：MASH）へ大きくシフトしている．そして近年では，肝線維化の進展ばかりでなく，改善の機序も解析されるようになり，その主役となる細胞，分子基盤が明らかになってきている．肝障害の原因療法と共に解明されてきた分子基盤に基づく線維化改善療法，再生療法の開発も進みつつある．本稿ではそれらを概説したい．

70歳代男性．約10年前にインターフェロン併用療法によりC型慢性肝炎はSVRとなったが，通院が途絶えていた．貧血精査にて造影CTを施行したところ，乏血性の多発肝腫瘍を認めた．肝生検で高分化型肝細胞癌と診断され，全身薬物療法を選択しデュルバルマブ＋トレメリムマブを導入したが，3コースでPDとなり，次治療としてレンバチニブを開始した．2カ月後Grade 3の肝障害が出現し，薬物性肝障害および免疫チェックポイント阻害薬（ICI）によるirAEを疑った．PSLによる治療を開始したが，その後IgA HEV抗体陽性の報告が到着し急性E型肝炎と診断された．irAEの合併も考えられ，PSLの減量・中止は困難となりHEV感染は持続した．5カ月後に肝障害の悪化を認め，リバビリンを開始したところ，ウイルス量の減少とともに肝障害も改善した．今後はICI治療に合併するE型肝炎の慢性化にも注意を払うべきと考える．

Throughout Japan, initiatives to provide information and promote public awareness of accurate knowledge regarding hepatitis are being implemented. As part of the awareness-raising activities, we conducted an investigation using a quiz for knowledge enlightenment about viral hepatitis. The hepatitis quiz was administered to >1,000 individuals. The correct answer rates for questions about symptoms, liver function, therapy for viral hepatitis, and route of infection were 81.8%, 86.5%, 75.8%, and 71.6%, respectively. Of the respondents, 92.6% correctly identified the appropriate laboratory procedure for viral hepatitis. Only 53.1% of the respondents knew that viral hepatitis was the main cause of liver cancer. The hepatitis quiz is a useful tool for determining the extent of knowledge regarding hepatitis.

Patients with HBV reactivation-related hepatitis were evaluated in Gunma Prefecture, Japan, between January 2012 and December 2024, wherein 11 cases were identified. Primary underlying diseases included malignant lymphoma (5 cases), rheumatoid arthritis (3 cases), and other conditions (3 cases), and identified causes included insufficient awareness on reactivation (5 cases) and inadequate monitoring (6 cases). Outcomes included recovery in eight cases and death in three. These findings underscore the need for re-educating non-specialists in hepatology and establishing a system that facilitates multidisciplinary monitoring and verification, rather than relying solely on the attending physician to prevent HBV reactivation-related hepatitis.