Autoimmune Hepatitis

Introduction

Autoimmune hepatitis is a chronic immune-mediated liver injury characterised by:

1. Serum antibodies and peripheral blood T-cells reactive with self-proteins
2. Strong association with other autoimmune disorders
3. High levels of immunoglobulins, especially IgG

Epidemiology

Most common in women aged 20 to 30 years old.

Risk factors

• Genetics e.g. HLA-DR4
• Viral infection e.g. hepatitis A, Epstein-Barr virus

Associated conditions

• Pernicious anaemia
• Hashimoto’s thyroiditis
• Ulcerative colitis
• Thyrotoxicosis
• Myxoedema

Pathophysiology

The cause is unknown. It is thought to occur following the production of T-cell mediated events against the liver, producing a progressive necroinflammatory process.

Clinical features

Most patients have vague chronic symptoms, including fatigue, anorexia and mild jaundice.

Acute presentation affect 25% of patients and can lead to significant liver necrosis and failure. Features include:

• Acute hepatitis
• Cirrhosis
• Jaundice
• Hepatosplenomegaly
• Fever
• Arthralgia
• Vitiligo

Investigations

Serum:

• LFT: very high ALT, elevated GGT
• Immunoglobulins: elevated IgG
• Antibodies: elevated ANA (antinuclear antibody) and SMA (anti-smooth muscle antibody)

Biopsy of the liver is also useful in confirming hepatitis on histology.

Management

Immunosuppression is the best treatment option for autoimmune hepatitis. Steroids and azathioprine induce remission in more than 80% of patients. Immunosuppressive treatment should be lifelong.

Acute management

30-40mg prednisolone for 2 weeks.

Maintenance management

Low-dose prednisolone or azathioprine can be used for long-term management of autoimmune hepatitis.

Prognosis

Although treatment significantly reduces progression, end-stage disease still occurs in some patients. Transplantation can be useful in advanced disease although the disease may recur.