Distribution of antibody to hepatitis A antigen in a population of commerical plasma doners.

Plasma samples from 245 regular plasma donors for Plasma Alliance, Inc. (Knoxville, Tenn.) were tested for the presence of antibody to hepatitis A antigen. Antibody was detected at an immune adherence hemagglutination titer of 1:10 or greater in 37% (91 of 245) of the donors. A statistically significant difference in the frequency of anti-hepatitis A was found between the 18- to 29-year-old group (30%) and the 30- to 49-year-old group (57%). No significant differences between whites and blacks or males afemales were observed. Eighty percent of the donors were in the age range of 18 to 29 years, whereas 48% of the higher-titered plasmas (1:1,000 or greater) were in the 30 to 49 age group. By preselection of donors, it would be possible to produce an immune serum globulin with a specific anti-hepatitis A titer.