Clinical Characteristics of Genuine Acute Autoimmune Hepatitis

GE Port J Gastroenterol. 2023 Jul 12;31(3):173-181. doi: 10.1159/000531018. eCollection 2024 Jun.

Abstract
in English, Portuguese

Introduction: Autoimmune hepatitis (AIH) has a spectrum of symptoms ranging from asymptomatic disease to acute severe hepatitis, chronic hepatitis, and decompensated cirrhosis. The acute presentation is not rare and could represent genuine acute AIH (GAAIH) or acute exacerbation of chronic autoimmune hepatitis. We aimed to identify the prevalence, clinical features, and prognostic factors associated with GAAIH and compare these cases with acute exacerbation of chronic AIH.

Methods: This cross-sectional observational study evaluated patients with acute AIH presentation, defined as total bilirubin >5 times the upper limit of normality (xULN) and/or alanine aminotransferase >10 xULN, and no prior history of liver disease. Histology findings of acute disease defined GAAIH. Bivariate analyses were performed to identify factors associated with the GAAIH, when compared with acute exacerbation of chronic AIH.

Results: Seventy-two patients with acute presentation of AIH were included and six (8.3%) of them presented GAAIH. Comparative analysis between patients with GAAIH and patients with acute exacerbation of chronic AIH revealed that prothrombin activity (96% [74-100] vs. 61% [10-100]; p = 0.003) and albumin levels (3.9 ± 0.2 g/dL vs. 3.4 ± 0.5 g/dL; p < 0.001) were higher in patients with GAAIH. The International Autoimmune Hepatitis Group score was higher in patients with acute exacerbation of chronic AIH (18.5 [8-23] vs. 16.5 [15-17]; p = 0.010). Compared to 15.2% of acute exacerbation of chronic AIH, complete therapeutic response to treatment was achieved in 67.7% of cases with GAAIH (p = 0.018).

Conclusions: GAAIH was rare (8.3%), and patients with this presentation exhibited more preserved liver function tests, suggesting that most cases presenting with loss of function are acute exacerbation of chronic AIH. Additionally, patients with GAAIH had a better complete therapeutic response, suggesting a more preserved liver function at presentation, and early diagnosis has a positive therapeutic implication.

Introdução: A hepatite autoimune (HAI) apresenta um espectro de sintomas que varia de doença assintomática a hepatite aguda grave, hepatite crónica e cirrose descompensada. A apresentação aguda não é rara e pode representar hepatite autoimune aguda genuína (HAIAG) ou exacerbação aguda de hepatite autoimune crónica (EAHAIC). O nosso objetivo foi identificar a prevalência, caraterísticas clínicas e fatores prognósticos associados à HAIAG, e comparar esses casos com EAHAIC.

Métodos: Estudo observacional, transversal, incluindo doentes com apresentação aguda de HAI, definida como bilirrubina total > 5 vezes o limite superior da normalidade (xLSN) e/ou ALT > 10 xLSN, e sem história prévia de doença hepática. HAIAG foi definida pela presença de achados histológicos de doença aguda. Análises bivariadas foram realizadas para identificar fatores associados à HAIAG, quando comparado com o EAHAIC.

Resultados: Foram incluídos setenta e dois doentes com apresentação aguda de HAI, dos quais seis (8.3%) com HAIAG. A análise comparativa entre doentes com HAIAG e doentes com EAHAIC mostrou que a atividade de protrombina (96% (74-100) versus 61% (10-100; p=0.003) e os níveis de albumina (3,9 ± 0,2 g/dL vs. 3,4 ± 0,5 g/dL; p < 0,001) foram significativamente mais elevados em pacientes com HAIAG. O score do Grupo Internacional de Hepatite Autoimune foi mais elevado em doentes com EAHAIC (18.5 (8-23) versus 16.5 (15-17); p=0.010). A resposta terapêutica completa ao tratamento foi alcançada em 66.7% dos casos de HAIAG (vs. 15,2% na EAHAIC, p=0,018).

Conclusões: A HAIAG é rara (8.3%), e os doentes com esta apresentação mostraram testes de função hepática mais preservados, sugerindo que a maioria dos casos com perda de função são EAHAIC. Além disso, os doentes com HAIAG tiveram maior taxa de resposta terapêutica completa, sugerindo que uma função hepática mais preservada na apresentação e o diagnóstico precoce tem uma implicação terapêutica positiva.

Keywords: Alanine transaminase; Autoimmune hepatitis; Prognosis; Prothrombin; Serum albumin; Symptom flare up; Treatment outcome.

Grants and funding

This study was funded by the Coordination for the Improvement of Higher Education Personnel (CAPES) research support agency, Brazil.