Autoimmune Hepatitis
BSG guidelines for diagnosis and management of autoimmune hepatitis. Published: Apr 2025.
Background Information
Risk Factors
More common in females (3:1)
Patients may have associated autoimmune diseases:
- Autoimmune thyroid disease
- T1DM
- Coeliac disease
- Vitiligo
- Rheumatoid arthritis
Clinical Features
Up to 40% patients are asymptomatic, often detected via incidental abnormal LFTs.
There are 2 main clinical patterns:
| Non-specific presentation |
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| Acute hepatitis-like presentation |
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Complications
Key complications:
- Decompensated liver disease
- Cirrhosis and hepatocellular carcinoma
Diagnosis
Diagnostic approach (all 3 steps are necessary for diagnosis):
- Step 1: exclude alternative causes of liver diseases
- Step 2: LFTs and serology (blood tests)
- Step 3: liver biopsy
Excluding Alternative Causes of Liver Diseases
| Exclude biliary obstruction |
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| Viral hepatitis and infection screen | All patients:
In acute / icteric presentations, also:
Also consider HSV and varicella zoster in immunocompromised patients |
| Exclude metabolic / genetic liver disease |
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Blood Tests
LFTs
Autoimmune hepatitis typically gives a hepatocellular LFT pattern
- ↑↑ AST and ALT (often <1,000 IU/L)
- Normal ALP and GGT
In acute disease:
- ↑ Bilirubin (but ALP is still normal / mildly elevated)
- ↑ INR
Serology
| 1st line antibodies |
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| Additional antibody tests |
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There are 2 main types of serology patterns in autoimmune hepatitis (but it is of limited clinical significance):
- Type 1 (most common): +ve anti-SMA and ANA
- Type 2: +ve anti-LKM-1 and anti-LC1
- Anti-SLA/LP can be present in either type and is highly specific
Liver Biopsy
If autoimmune hepatitis is likely (i.e. other causes of liver disease excluded, and serology is suggestive), liver biopsy should be performed routinely (unless the risks of biopsy clearly outweigh the benefits)
Typical histological findings:
- Interface hepatitis
- Portal lymphoplasmacytic infiltrate
- Lobular hepatitis
Liver biopsy is crucial in autoimmune hepatitis to confirm the diagnosis, exclude disease mimics, detect overlap syndromes (e.g. with PBC and PSC), and assess the degree of fibrosis.
Unlike many other autoimmune or metabolic liver diseases (PSC, PBC, haemochromatosis and Wilson’s disease), which do NOT routinely require liver biopsy to confirm diagnosis, autoimmune hepatitis is an exception that typically requires a routine liver biopsy for diagnostic confirmation.
Management
Definitive Management
Most patients would need immunosuppressive treatment (regardless of symptoms) with an induction-maintenance strategy.
| 1st line |
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| 2nd line |
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The treatment goal is to normalise AST, ALT and IgG. Once biochemical remission is achieved, prednisolone can be gradually tapered and stopped, while azathioprine is continued as maintenance therapy.
Ensure to check TPMT activity before starting azathioprine. Patients with absent or very low TPMT activity should NOT receive azathioprine, as they are at risk of severe myelosuppression.
TPMT is responsible for metabolising azathioprine metabolites. Therefore, absent or markedly reduced TPMT activity leads to accumulation of active azathioprine metabolites, resulting in bone marrow toxicity and myelosuppression.