Natural antibody level in old age.
Antibacterial antibodies were determined with a passive hemagglutination micromethod using the Boivin extract of eight different strains of bacteria. Correlation between antibody values of different specificities and between the summarized titer values and individual antibody titers were found. A significant decrease in the average of the summarized titer values was observed especially for persons over 70. The possibility of genetic regulation of normal antibody levels is suggested. The question whether the decrease in agglutinating antibody level in old age is due to the decreased activity of the corresponding immunocompetent cells or is secondary to other changes occuring in old age, is discussed.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging; D000906:Antibodies / Q000032:analysis*; D001424:Bacterial Infections / Q000276:immunology; D006386:Hemagglutination Tests; D006801:Humans; D007111:Immunity, Cellular; D008875:Middle Aged
D000906:Antibodies