Autoimmune hepatitis (AIH) usually comes to attention through fatigue, and much of its clinical picture is built from non-specific complaints and laboratory clues rather than a single distinctive sign.
Symptoms and physical findings
More than 85% of patients mainly complain of easy fatiguability (fatigue). The physical examination is completely normal in about 25% of adults. When findings are present, the most common are hepatomegaly and splenomegaly, an enlarged liver and spleen. In 14-40% of patients there is a concurrent autoimmune-mediated disorder outside the liver, most often autoimmune thyroiditis or Graves disease.
Psychological features
Depression and anxiety are very common in these patients, especially after diagnosis, when they are driven by fear of progression. Physiological stress of any kind correlates with exacerbation of AIH, possibly because stress increases the production of pro-inflammatory cytokines.
Laboratory findings
The laboratory hallmark of AIH is an increase in IgG with normal IgA and IgM — a selective rise in one immunoglobulin class rather than a general rise in all of them. AST, ALT and γ-globulin levels reflect the severity of the disease.
Other laboratory changes are common but less specific. Hyperbilirubinaemia is present in more than 80% of cases, usually within 3-fold above the upper limit of normal. Alkaline phosphatase (ALP) is raised in more than 80% of cases, but in 67% it is only up to 2-fold above the upper limit of normal; an ALP elevation of more than 4-fold above that limit makes the diagnosis of AIH challenging, because it points toward a cholestatic disease instead. Hyperferritinaemia, with a high serum iron concentration, is also common, and serum vitamin D is low in 81% of patients. Failure to correct the vitamin D is a prognostic marker of treatment failure, with a high chance of cirrhosis.