Chapter 26-7: Autoimmune Hepatitis

TEXTBOOK PRESENTATION

The clinical presentation is variable, ranging from asymptomatic transaminase elevation to nonspecific constitutional symptoms, to advanced liver disease.

DISEASE HIGHLIGHTS

1. A chronic inflammatory disease of the liver, although 25% of cases present as acute hepatitis

2. Annual incidence of 1.4 cases/100,000; 3–4 times more common in women than in men

3. Wide age distribution, occurring in infants and octogenarians

4. 27% 10-year survival in untreated patients

5. Drug-induced autoimmune hepatitis, reported with minocycline, nitrofurantoin, atorvastatin, and infliximab, has a more benign course than idiopathic autoimmune hepatitis.

EVIDENCE-BASED DIAGNOSIS

1. Autoantibodies

   1. Antinuclear antibodies (ANA): sensitivity, 32%; specificity, 76%; LR+, 1.3; LR–, 0.89

   2. Anti-smooth muscle antibody (SMA): sensitivity, 16%; specificity, 96%; LR+, 4; LR–, 0.87

   3. ANA and SMA: sensitivity, 43%; specificity, 99%; LR+, 43; LR–, 0.57

   4. Diagnostic criteria have been developed (Table 26-7).

      1. For a diagnosis of probable autoimmune hepatitis (6 points): sensitivity, 88%; specificity, 97%; LR+, 29; LR–, 0.12

      2. For a diagnosis of definite autoimmune hepatitis (≥ 7 points): sensitivity, 81%; specificity, 99%; LR+, 81; LR–, 0.19

TREATMENT

1. Treatment is indicated for all patients with evidence of active inflammation, either by transaminase elevation or histology.

2. Prednisone alone, or prednisone and azathioprine are used to induce remission; occurs in 85% of patients

3. Many patients require maintenance therapy, most commonly with azathioprine.

4. Other immunosuppressive agents are used in patients who do not respond to or cannot tolerate the first-line treatments.

5. Liver transplant is often successful in patients with cirrhosis and decompensated end-stage liver disease, although autoimmune hepatitis can recur in the transplanted liver.