Aspartate aminotransferase-to-platelet ratio index (APRI) reliably excludes advanced fibrosis and cirrhosis in treated autoimmune hepatitis

Abstract

Introduction and Objectives:

Monitoring liver fibrosis during treatment of autoimmune hepatitis (AIH) is important to guide treatment. Transient elastography (TE) is not always available. Existing non-invasive fibrosis scores have been assessed primarily at diagnosis but not during treatment. This study aims to develop a non-invasive AIH fibrosis score (AIHFS) and validate its performance-alongside with existing fibrosis scores-for excluding advanced fibrosis (>= F3 on TE) and cirrhosis (F4 on TE) during AIH treatment.

Patients and Methods: This study included adult patients with AIH and variant syndromes from Leiden (derivation cohort, n = 73) and Vienna (validation cohort, n = 81). All patients had been treated for at least 6 months and had valid TE and routine laboratory tests within 1 months of TE. Existing fibrosis scores were calculated and a novel AIHFS was developed using multivariate regression. TE served as the reference standard. Results: The aspartate aminotransferase-to-platelet ratio index (APRI) and AIHFS (comprising APRI and albumin) were the only fibrosis scores significantly associated with liver stiffness during treatment. AIHFS did not outperform APRI. APRI demonstrated a high negative predictive value for advanced fibrosis (>= F3 on TE) and cirrhosis (F4 on TE): 86% and 93 % in the derivation cohort and 84% and 95 % in the validation cohort, respectively. Based on an APRI threshold of 0.4874, only 22-40% of patients would require further diagnostic assessment. Conclusions: APRI is a simple, non-invasive, widely applicable score that reliably excludes advanced fibrosis (>= F3 on TE) and cirrhosis (F4 on TE) during AIH treatment, potentially reducing the need for additional investigations.