Secretory IgA anti-HAV in bile of hepatitis A patients

Hepatitis A virus (HAV) is generally excreted in the feces, and secretory immunoglobulin (Ig) A anti-HAV may play an important role in protecting re-infection of HAV. To determine whether secretory IgA anti-HAV is present in the saliva of patients with HAV infection, saliva samples from 13 patients with acute hepatitis A and 11 with acute hepatitis B or C were tested for secretory IgA and IgA anti-HAV. IgA, IgM and IgG concentrations in saliva were also measured in these patients. Secretory IgA and IgA anti-HAV were assayed using radioimmunoassay. IgA, IgM and IgG concentrations were significantly higher in acute phase (within 3 weeks of clinical onset) than convalescence phase (after 4 weeks of clinical onset) of hepatitis A patients. There were no elevations in immunoglobulin concentrations in acute hepatitis B and C. Secretory IgA and IgA anti-HAV was found only in the acute phase of hepatitis A patients; they returned to normal range in the convalescence phase. Secretory IgA and IgA anti-HAV in saliva of hepatitis A patients may have a role in protecting against HAV re-infection.