How to prevent and manage Hepatitis A in patients with autoimmune hepatitis?

Hepatitis A and Autoimmune Hepatitis: Prevention and Management

Vaccination is Critical and Should Be Done Early

All patients with autoimmune hepatitis (AIH) who are susceptible to hepatitis A virus (HAV) infection should undergo vaccination as soon as possible, ideally before starting immunosuppressive therapy. 1

• Susceptibility to HAV infection is present in 51% of patients with autoimmune liver diseases, with an incidence of HAV infection of 1.3 per 1,000 person-years. 1
• Protective antibodies develop in 100% of patients vaccinated for HAV, though response rates are lower in immunosuppressed patients—but not so low as to preclude vaccination. 1
• Vaccination status should be reviewed and updated ideally prior to institution of immunosuppressive therapy, as live attenuated vaccines are contraindicated in highly immunosuppressed patients, but recombinant and inactivated vaccines (like HAV vaccine) are considered safe. 1

HAV Can Trigger Autoimmune Hepatitis

Hepatitis A virus infection is a recognized trigger that can induce autoimmune hepatitis in predisposed individuals. 1, 2, 3

• Cases of AIH presenting shortly after documented HAV infection have been reported, with patients developing classic features including autoantibodies (anti-smooth muscle antibody), hypergammaglobulinemia, and histological evidence of chronic hepatitis after acute HAV infection. 2, 3
• In one documented case, a 7-year-old patient developed autoimmune hepatitis 10 weeks after HAV infection, presenting with hyperbilirubinemia (12 mg/dl), anti-smooth muscle antibodies (1:320), and marked hypergammaglobulinemia (3700 mg/dl), requiring immunosuppressive therapy. 3
• This underscores the importance of HAV vaccination to protect patients not only from acute infection but also from potential autoimmune complications. 2

Management of AIH Remains Standard Regardless of HAV Trigger

If autoimmune hepatitis develops following HAV infection, treatment follows standard AIH management principles with corticosteroids and azathioprine. 4, 5

• The combination of prednisolone (30 mg/day initially, tapering to 10 mg/day) plus azathioprine (1-2 mg/kg/day) achieves remission in 80-90% of AIH patients, regardless of the triggering event. 4, 5
• Treatment should be initiated immediately in patients with severe disease manifestations: AST/ALT >10-fold upper limit of normal (ULN), or ≥5-fold ULN with serum globulin ≥2-fold ULN, or histological findings of bridging necrosis or multilobular necrosis. 5
• Serum aminotransferases typically improve within 2 weeks, with biochemical remission achieved within 6-12 months in most patients. 5

Practical Vaccination Timing and Monitoring

Check HAV immunity status (anti-HAV IgG) at the time of AIH diagnosis before starting immunosuppression. 1

• If seronegative, administer HAV vaccine immediately, as the vaccine is safe even in patients about to start immunosuppression. 1
• Patients on immunosuppressive therapy should have baseline and weekly monitoring of liver tests, blood sugar, and blood count for 4 weeks, then 1-3 monthly thereafter. 1
• The goal is to prevent HAV infection entirely through vaccination, as acute HAV infection in an immunosuppressed patient could complicate disease management and potentially trigger disease flares. 1

Common Pitfalls to Avoid

Do not delay HAV vaccination while waiting for "optimal" immunosuppression levels—vaccinate as early as possible, even if some immunosuppression is already present, as partial protection is better than none. 1

• Do not confuse acute HAV infection with an AIH flare; check HAV IgM if acute hepatitis develops in a previously stable AIH patient. 1, 2
• Remember that HAV vaccination failures are mainly attributed to concomitant immunosuppressive therapy, so vaccinating before or early in treatment maximizes response. 1
• Ensure hepatitis B vaccination is also performed, as susceptibility to HBV is even higher (86%) in AIH patients. 1