Autoimmune hepatitis

Chronic autoimmune hepatitis is a chronic hepatitis of unknown origin that predominantly affects young and middle aged women. It is associated with HLA types A1, B8, DR3 and Dw3.

The cause of autoimmune hepatitis is unknown, but evidence implicates both genetic and environmental factors in its pathogenesis

• an imbalance between effector and regulatory mechanisms leads to the breakdown of immune tolerance and the consequent development of an autoimmune attack
• signalling pathways that have been implicated in the pathogenesis of autoimmune hepatitis involve the proinflammatory cytokines interferon-gamma, IL-12, tumour necrosis factor-alph, IL-6, and IL-23

There are reduced numbers of T-suppressor cells which results in the production of autoantibodies against hepatocyte surface antigens.

The condition may be referred to as lupoid hepatitis as a positive LE cell test occurs in about 15% of patients. However, the condition is distinct from classical systemic lupus erythematous.

The mainstay of treatment is non-specific immunosuppression, consisting of steroids with or without azathioprine

• although most patients respond satisfactorily to steroid and thiopurine-based treatment regimens, up to 40% relapse and 10% undergo liver transplantation

Hepatocellular carcinoma develops in 1-9% of patients with autoimmune cirrhosis, with an annual incidence of 1.1-1.9% (2)

Reference:

• Liberal R et al. Established and novel therapeutic options for autoimmune hepatitis. Lancet 2021; DOI: https://doi.org/10.1016/S2468-1253(20)30328-9
• Muratori L, Lohse A W, Lenzi M. Diagnosis and management of autoimmune hepatitis BMJ 2023; 380 :e070201 doi:10.1136/bmj-2022-070201