Letter to the Editor: Long-term experience in treating autoimmune hepatitis with acute presentation

To the editor, We read with interest the article by Enke et al1 who reviewed clinical, laboratory, and histological data of acute liver failure (ALF) due to autoimmune hepatitis (AIH) enrolled in the ALF Study Group Registry between 1998 and 2019 in the US and identified variables that predict 21-day transplant-free survival. We applaud their efforts in treating this rare and life-threatening syndrome. From over a 20-year review, we could have a high short-term mortality of AIH-ALF reconfirmed in the US as well as in Japan.2–4 We also understand the analyses of incomplete nationwide data by the Adjudication Committee are complicated, as the authors described. Difficulty in discussing AIH with acute presentation would largely depend on the lack of a clear definition of itself and the disease severity, which should be resolved in the future. The definitions have been different among most studies. The most important strategy for difficult-to-diagnose and difficult-to-treat liver diseases like acute AIH is to diagnose and treat the "non-severe" disease before developing into a severe disease; therefore, we have analyzed various aspects of non-severe acute AIH patients. In our recent analysis of acute AIH, 69% of non-severe acute AIH patients had no symptoms and were discovered by regular medical checkups.5 Thus, the clinical onset of acute AIH is often insidious, and the various intervals from the onset would be longer than those reported. As a result, it develops in a subacute clinical fashion.2,3 We infer the progression of the disease would be more gradual than other etiologies causing ALF,2 with the mixture of severe necrosis and prosperous regeneration in the liver before the development of impaired regeneration (Figure 1).FIGURE 1: Disease types of acute liver failure (ALF) and late-onset hepatic failure (LOHF) due to autoimmune hepatitis in our unit (Chiba University)3 and Japanese nationwide survey.4 The diagnosis of ALF and LOHF was performed based on the Japanese diagnostic criteria. ALF acute type and ALF subacute type develop HE within 10 days and between 11 and 56 days after the onset of disease symptoms, respectively. LOHF develops HE between 8 and 24 weeks after the onset of disease symptoms. Abbreviation: ALF, acute liver failure.As the authors described, more data are needed to better understand the disease process due to uncertainties surrounding the diagnosis and treatment of acute severe AIH. Accumulation of new insight into clinical, biochemical, immunological, radiological, and histological features by experienced hepatologists and hepatopathologists is necessary for the early diagnosis of acute AIH.