The anti-Fya titre in the pretransfusion specimen would be expected to be lower than the titre obtained from the 2-week post-transfusion specimen.

  • The transfused donor RBC would have stimulated increased antibody production.
  • The increase in titre would partially depend on how many Fy(a+) donor RBC are still present to adsorb antibody from the patient's plasma at the time of titration.