Differences exist between the ABO antibody titres of adults. What are some of the causes?

Variables that may affect ABO antibody titres in adults include:

  • variations in immune competence between individuals
  • exposure to ABO-incompatible fetal red cells via pregnancy
  • vaccinations
  • innoculaton with soluble A and B substances prior to plasmapheresis for ABO antisera (historical source of human ABO typing sera)
  • diseases such as a- and hypo-gammaglobulinemia
  • advancing age