IgG antiHEV appears to afford protection against re-infection. These tests are not available commercially. Elevations can be associated with underlying liver disease or exposure to other hepatotoxins. It is not clear if the magnitude of elevation correlates with the histological severity. Serum bilirubin elevations occur in both the total and direct fractions.
Hemolysis is unusual.
In most cases, bilirubin levels take longer to return to normal than aminotransferase levels. Many patients develop a mild leukocytosis. If associated with fever, bacteremia should be suspected. More commonly, WBC counts are decreased. Differential counts may show atypical cells and lymphocytosis.