Introduction. Autoimmune hepatitis (AIH) is a chronic liver disease with a relevant inflammatory component and an unknown etiology. Evidence for clinical characteristics and risk factors in large cohorts of patients with acute AIH (AAIH) is lacking. We clinically characterized patients with AAIH, the prevalence of a combined adverse outcome (death or liver transplantation (LT)), and its risk factors. Methods. A retrospective study of adult patients diagnosed with AAIH at three centers (Santiago, Chile; 2000–2018) was conducted. Clinical and laboratory characteristics were obtained. A liver biopsy was performed for all patients. Descriptive statistics and logistic regression models were used. Results. A total of 126 patients were admitted; 77% were female, 33 (26.2%) had a severe presentation, and 14 (11.1%) had a fulminant presentation. Overall, 24 patients (19.0%) lacked typical autoantibodies, and 26.2% had immunoglobulin G levels in the normal range. The most frequent histological findings were plasma cells (86.5%), interface hepatitis (81.7%), and chronic hepatitis (81.0%). Rosettes were uncommon (35.6%). Advanced fibrosis was present in 27% of patients. Combined adverse outcomes occurred in 7.9% of cases, all fulminant with histological cholestasis. Alkaline phosphatase, bilirubin, and prothrombin less than 50% were independent risk factors for in-hospital death or LT ( value <0.05). Although corticosteroid treatment was associated with better outcomes (OR 0.095, value = 0.013), more severe patients were less likely to receive this therapy. Discussion. In this large cohort of patients with AAIH, clinical characteristics differ from those reported in patients with chronic AIH. Fulminant hepatitis, histological cholestasis, alkaline phosphatase, bilirubin, and prothrombin were associated with death/LT.

中文翻译：

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急性表现的自身免疫性肝炎：126 例患者的临床、生化和组织学特征

简介。自身免疫性肝炎 (AIH) 是一种具有相关炎症成分和未知病因的慢性肝病。缺乏大量急性 AIH (AAIH) 患者的临床特征和危险因素的证据。我们对 AAIH 患者、综合不良结局（死亡或肝移植 (LT)）的发生率及其危险因素进行了临床表征。方法。对三个中心（智利圣地亚哥；2000-2018 年）诊断为 AAIH 的成年患者进行了回顾性研究。获得了临床和实验室特征。对所有患者进行了肝活检。使用描述性统计和逻辑回归模型。结果. 共收治126名患者；77% 为女性，33 人（26.2%）有严重表现，14 人（11.1%）有暴发性表现。总体而言，24 名患者 (19.0%) 缺乏典型的自身抗体，26.2% 的免疫球蛋白 G 水平在正常范围内。最常见的组织学发现是浆细胞（86.5%）、界面性肝炎（81.7%）和慢性肝炎（81.0%）。玫瑰花结不常见（35.6%）。27% 的患者出现晚期纤维化。7.9% 的病例出现综合不良后果，均以组织学胆汁淤积暴发。碱性磷酸酶、胆红素和凝血酶原低于 50% 是院内死亡或 LT 的独立危险因素（值 <0.05）。尽管皮质类固醇治疗与更好的结果相关（OR 0.095，值 = 0.013），更严重的患者不太可能接受这种治疗。讨论。在这一大型 AAIH 患者队列中，临床特征与报告的慢性 AIH 患者不同。暴发性肝炎、组织学胆汁淤积、碱性磷酸酶、胆红素和凝血酶原与死亡/LT 相关。