Autoimmune Hepatitis
Autoimmune hepatitis is a condition in which the patient's own immune systems attacks the liver causing inflammation and liver cell death.
The condition is chronic and progressive and may lead to cirrhosis, liver
failure, and the need for liver transplantation. Although the disease is chronic, many patients with
autoimmune hepatitis present acutely ill with jaundice, fever and sometimes symptoms of severe hepatic
dysfunction, a picture that resembles acute hepatitis. These patients are typically very ill at presentation.
Autoimmune hepatitis usually occurs in women (70 %) between the ages of 15 and 40. It can occur in men, though it is more rare.
Although the term
"lupoid" hepatitis was originally used to describe this disease, patients with systemic lupus erythematosus
do not have an increased incidence of autoimmune hepatitis and the two diseases are distinct entities.
Patients usually present with evidence of moderate to severe hepatitis with elevated serum ALT and AST
activities in the setting of normal to marginally elevated alkaline phosphatase and gammaglutamyltranspeptidase activities. The patient will sometimes present with jaundice, fever and right upperquadrant pain and occasionally systemic symptoms such as arthralgias (arthritis), myalgias (muscle aches), polyserositits and thrombocytopenia. Some patients will present with mild liver dysfunction and have only laboratory abnormalities as their initial presentation. Others will present with severe hepatic dysfunction. Fatigue is the hallmark of autoimmune hepatitis.
Autoimmune hepatitis should be suspected in any young patient with hepatitis (elevated liver tests), especially those without risk
factors for alcoholic, drug, metabolic or viral etiologies. Serum protein electrophoresis and testing for
autoantibodies are of central importance in the diagnosis of autoimmune hepatitis. Patients with one
subtype of autoimmune hepatitis have serum gamma-globulin concentrations more than twice normal and
sometimes antinuclear antibodies and/or anti-smooth muscle (anti-actin) antibodies. Patients with another
subtype may have normal or only slightly elevated serum gamma-globulin concentrations but will have
antibodies against a particular cytochrome p450 isoenzyme that are called anti-LKM (liver kidney
microsome).
Patients in whom a diagnosis of autoimmune hepatitis is suspected should have a liver biopsy. If the biopsy
is consistent, treatment with steroids (prednisone or pednisolone) and azathioprine (Imuran) is begun
immediately. These are tapered over the next 6 to 24 months depending upon the patient's course. If
immediate liver biopsy is contraindicated because of a prolonged prothrombin time or thrombocytopenia,
steroids and azathioprine should be started prior to biopsy if the diagnosis of autoimmune hepatitis is likely
based on clinical criteria (e.g. a young woman with severe hepatitis, elevated serum gamma-globulin
concentration, negative risk factors and serologies for viral hepatitis). The patient will often rapidly
improve and biopsy should be performed to confirm the diagnosis as soon as the prothrombin time
decreases and platelet count increases to within safe ranges.
About two-thirds to three quarters of patients with autoimmune hepatitis respond to treatment based on the
return of serum ALT and AST activities to normal and an improved biopsy after several months. Some
patients relapse as steroids and azathioprine doses are tapered or stopped and need chronic maintenance
medications. Over the long term, many patients develop cirrhosis despite having a response to treatment,
and patients who do not respond to treatment will almost always progress to cirrhosis. If end-stage liver
disease develops, orthotopic liver transplantation is an effective procedure.