THE DEVELOPMENT OF ABO ISOHEMAGGLUTININS IN TAIWANESE

To evaluate the developmental pattern of ABO isohemagglutinins in Taiw anese, 644 blood samples (349 males, 295 females), including cord bloo d, were collected from individuals with ages ranging from newborn to 8 3 years. Synthesis of anti-A and anti-B could be demonstrated in most Taiwanese infants by 2-4 months of age, increasing progressively to re ach adult levels (titers of 1:32-1:256) at around I year of age. Peak levels were reached at between 3-10 years of age and then declined wit h advancing years, with individuals of 80 years of age and over showin g reduced levels similar to those seen in 6-to 12-month-old infants. S ex and parity did not appear to influence ABO isohemagglutinin develop ment.