Background & Aims: Antimitochondrial antibodies (AMA) are specific markers for the diagnosis of primary biliary cholangitis (PBC) but can also be found occasionally in patients with autoimmune... Show moreBackground & Aims: Antimitochondrial antibodies (AMA) are specific markers for the diagnosis of primary biliary cholangitis (PBC) but can also be found occasionally in patients with autoimmune hepatitis (AIH). The present large multicentre cohort study assessed the prevalence and significance of AMA in AIH-patients. Methods: 123 AMA-positive AIH-patients were investigated and compared with 711 age-matched AMA-negative AIH-patients and 69 patients with AIH/PBC variant.Results: AMA prevalence in AIH-patients was 5.1% (range: 1.2%-11.8%). AMA-positivity was associated with female sex (p = 0.031) in AMA-positive AIH-patients but not with liver biochemistry, bile duct injury on liver biopsy, disease severity at baseline and response to treatment compared to AMA-negative AIH-patients. Comparing AMA-positive AIH-patients to those with AIH/PBC variant, there was no difference in disease severity. Regarding liver histology, AIH/PBC variant patients were characterized by the presence of at least one feature of bile duct damage (p<0.001). Response to immunosuppressive treatment was similar among groups. From AMA-positive AIH patients only those with evidence of non-specific bile duct injury had higher risk to progress to cirrhosis (HR=4.314, 95%CI: 2.348–7.928; p<0.001). During follow-up, AMA-positive AIH-patients had higher risk to develop histological bile duct injury (HR 4.654, 95%CI 1.829–11.840; p = 0.001). Conclusions: AMA presence is relatively common among AIH-patients, but their clinical significance seems important only when they co-exist with non-specific bile duct injury at the histological level. Therefore, a careful evaluation of liver biopsy seems of utmost importance in these patients. Show less
Biewenga, M.; Sarasqueta, A.F.; Tushuizen, M.E.; Jonge-Muller, E.S.M. de; Hoek, B. van; Trouw, L.A. 2020
Introduction: The complement system, an essential part of the innate immune system, is involved in various autoimmune diseases. Activation of the complement system by autoantibodies results in... Show moreIntroduction: The complement system, an essential part of the innate immune system, is involved in various autoimmune diseases. Activation of the complement system by autoantibodies results in immune activation and tissue damage. At the moment little is known about the role of the complement system in autoimmune liver disease, including primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH). Since inhibition of the complement system is currently being tested in several autoimmune diseases as a therapeutic option, its role in autoimmune liver disease requires further clarification.Methods: A review of the literature was performed on studies investigating complement activation in PBC, PSC and AIH. Since data on AIH were lacking immunohistochemical staining for IgG, C1q, C3d, C4d and C5b9 was performed on liver tissue of nine AIH patients, two healthy controls and one positive control (acute liver failure caused by paracetamol intoxication).Results: Immunohistochemical analysis in AIH revealed increased production of C3 and C4 by hepatocytes. Despite a strong staining for IgG in the immune infiltrate in AIH, C3d, C4d and C5b9 deposition was only present in one AIH patient and the deposition was restricted to the interface between portal tracts and liver parenchyma. No deposition was found in all other AIH patients or healthy controls.Literature review showed raised plasma C3 and C4 levels in AIH, PBC and PSC patients compared to healthy controls. For PBC and PSC no complement depositions at the bile ducts were reported.Conclusion and discussion: Although complement is involved in various autoimmune diseases, the role of complement in autoimmune liver disease seems limited. Therefore it is unlikely that complement inhibition will become a novel treatment option for these diseases. Show less
Bolier, R.; Vries, E.S. de; Pares, A.; Helder, J.; Kemper, E.M.; Zwinderman, K.; ... ; Netherlands Assoc Study Live 2017
