AGE DEPENDENCY OF ABO HISTO-BLOOD GROUP ANTIBODIES - REEXAMINATION OFAN OLD DOGMA

Current textbooks for transfusion medicine state that anti-A and/or an ti-B (anti-A/B) agglutination titers-and thus the respective antibody concentrations-reach their maximum in individuals 5 to 10 years old an d then gradually decline with the increasing age of the individual. Th is statement is largely based on a study by Thomsen and Kettel that da tes to 1929; In the present article, ABO antibodies in sera of 175 hea lthy persons aged 61 to 97 years, as well as sera of 170 newborn infan ts and children aged 0 to 17 years, were analyzed. Microhemagglutinati on tests were performed with all sera and complemented by ABO enzyme-l inked immunosorbent assays to measure the immunoglobulin class (IgM, I gG, and IgA) of the anti-A/B. As in a previous study using sera: of pe rsons aged 20 to 67 years, individual differences exceeded age-related changes for all variables. Median values of IgG and IgA anti-A/B were elevated in elderly persons of blood group O, whereas no significant changes were observed in other variables. in particular, the decrease in agglutination titers with the increasing age of the individuals was far less pronounced than previously described; even in sera of person s aged 90 to 97 years, median agglutination titers of 128 were found. Results in the sera of children confirm previously reported data that agglutination titers and IgM anti-A/B reached adult levels at the age of 5 to 10 years.