Complementary use of autoantibody detection methods facilitates diagnosis of juvenile autoimmune hepatitis and autoimmune sclerosing cholangitis

Abstract

Background and Aims: The diagnosis of juvenile autoimmune hepatitis (AIH) is challenging given its heterogeneous presentation. Autoantibodies, typically detected by immunofluorescence testing (IFT), together with liver histology, represent key diagnostic features. Polyreactive immunoglobulin G (pIgG) has recently emerged as a complementary biomarker in AIH. This retrospective multicentre study aimed to compare ELISA-based autoantibody testing and IFT on HEp-2 cells with the gold standard of IFT on rodent tissue sections in children with autoimmune and non-autoimmune liver diseases. Methods: Autoantibody detection was performed centrally at Hannover Medical School using three commercial antinuclear antibody (ANA) ELISAs, one commercial F-actin ELISA, one in-house pIgG ELISA, and IFT on HEp-2 cells, in comparison to the gold standard of IFT on rodent tissue sections. Samples from children with AIH (n = 69), autoimmune sclerosing cholangitis (AISC; n = 13) and other liver diseases (n = 120) were analysed from nine European centres. Results: The AUCs for the detection of AIH/AISC were moderate to good for ANA detection by IFT (gold standard of rodent tissue AUC: 0.748; HEp-2 AUC: 0.756) and were comparable to ELISA-based detection (0.622-0.772). Anti-smooth muscle antibody (SMA) IFT on rodent tissue yielded an AUC of 0.694. Specificity was increased to 100% by including the SMA staining pattern of vessels, glomeruli and tubules. ELISA-based quantification of anti-F-actin (AUC = 0.868) and pIgG (AUC = 0.844) showed the highest AUCs. While the majority of F-actin-positive children were pIgG-positive (80.3%), pIgG was also detected in 52.4% of F-actin-negative children with AIH. Conclusion: ELISA-based assays provide reliable ANA detection comparable to IFT. Anti-F-actin and pIgG ELISAs showed the highest accuracy for predicting juvenile AIH/AISC and may complement existing diagnostic criteria. (c) 2025 The Author(s). Published by Elsevier B.V. on behalf of European Association for the Study of the Liver (EASL). This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).