Analysis of serum hepatitis A virus antibody response in different courses of hepatitis A virus infection.

Changes in the serum hepatitis A virus antibody (anti-HAV) response in patients with different clinical courses of HAV infection were examined using immune adherence hemagglutination (IAHA). Anti-HAV was detected 2-6 weeks after the onset of clinical symptoms in patients with the typical course of acute hepatitis A and 1-4 weeks after the onset in those with fulminant hepatitis A. Maximal anti-HAV titers were observed 8-20 weeks after the onset of clinical symptoms, and changes in anti-HAV were similar in the typical and the prolonged course of acute hepatitis A, but maximal antibody titers were higher in the prolonged course. Maximal anti-HAV titers in patients with subclinical HAV infection were significantly lower than titers in patients with the typical and prolonged courses of acute hepatitis A, and in those with fulminant hepatitis A. High titers of anti-HAV remained positive for at least 6 years after infection in patients with clinical infection and for at least 4 years in patients with subclinical infection on follow-up. These findings suggest that the maximum anti-HAV titer correlates with the clinical severity of HAV infection; knowledge of the antibody response should be useful for analyzing the pathogenesis of HAV infection.