Purification of hepatitis A antigen from feces and detection of antigen and antibody by immune adherence hemagglutination

Abstract

Hepatitis A antigen (HA Ag) was purified from feces collected during acute illness from patients with naturally occurring viral hepatitis, type A. Positive fecal specimens were identified by immune electron microscopy, but for detection of HA Ag during purification immune adherence hemagglutination (IAHA) and microtiter solid phase radioimmunoassay were used. Isopycnic banding in cesium chloride, rate zonal separation in sucrose, and preparative zonal electrophoresis were used in various combinations for successive purification, and the purified antigen was successfully used in a test for antibody by IAHA. Seroconversions to HA Ag were demonstrated by IAHA in 20 instances of hepatitis A virus infection, but in none of six cases of type B hepatitis or three cases of posttransfusion hepatitis unrelated to hepatitis A or B viruses, nor in two individuals without hepatitis. In addition, the temporal pattern of antibody development during type A hepatitis was studied in serial sera from an experimentally infected chimpanzee. Antibody titers by IAHA correlated well with antibody ratings determined by immune electron microscopy.