AKT · Gastroenterology/Liverlow yield

Autoimmune hepatitis

Immune-mediated chronic hepatocellular inflammation (autoantibody-associated)

Overview

Chronic immune-mediated inflammation of the liver, typically in women (bimodal — young and peri/post-menopausal), associated with other autoimmune disease. Presents acutely (hepatitic) or with established chronic liver disease; raised IgG and autoantibodies (ANA, anti-smooth-muscle [type 1]; anti-LKM1 [type 2]). Responds to immunosuppression (steroids + azathioprine) — important because it's treatable.

Recognise

Fatigue, jaundice, RUQ discomfort, amenorrhoea; or asymptomatic deranged LFTs; or acute hepatitis/acute liver failure
Often other autoimmune disease (thyroid, coeliac, type 1 diabetes); women
Raised IgG, positive ANA/anti-smooth-muscle (type 1) or anti-LKM1 (type 2); hepatitic LFTs

Red flags

Acute liver failure presentation (coagulopathy/encephalopathy) → urgent specialist
Progression to cirrhosis if untreated

Differentials & how to tell them apart

Viral hepatitispositive viral serology, no autoantibodies/raised IgG

Drug-induced/alcoholic hepatitishistory; AST:ALT ratio (alcohol)

Primary biliary cholangitischolestatic (ALP↑), anti-mitochondrial antibody, itch — overlap syndromes exist

Wilson diseaseyoung, low caeruloplasmin, KF rings (see endocrine/metabolic)

Investigations

Autoantibodies (ANA, anti-smooth-muscle, anti-LKM1), raised IgG; hepatitic LFTs; LIVER BIOPSY (interface hepatitis, plasma cells); exclude viral/other causes.

Management

Immunosuppression — prednisolone (induce) + azathioprine (maintain)

1Confirm with autoantibodies/IgG and biopsy after excluding other causes. Induce remission with corticosteroids; add azathioprine for maintenance/steroid-sparing.Gate: It is a TREATABLE cause of deranged LFTs/cirrhosis — recognise the autoantibody/raised-IgG pattern in a woman with another autoimmune disease and treat with immunosuppression rather than missing it
2Long-term azathioprine; monitor LFTs/IgG; transplant for end-stage disease; manage overlap syndromes.

Corticosteroids (prednisolone) to induce remission — the treatable point — good response

Azathioprine (steroid-sparing maintenance) — maintain remission/reduce steroid dose

Liver transplant — for end-stage disease/acute liver failure

Key points

Woman + other autoimmune disease + hepatitic LFTs + ANA/anti-smooth-muscle + raised IgG = autoimmune hepatitis → steroids + azathioprine. Treatable — don't miss it.

Monitor & prognosis

LFTs/IgG; cirrhosis surveillance.

Good with treatment; cirrhosis if missed.

Source: BSG; EASL