Three days after SJ was transfused and the samples were sent for investigation (which included a holiday long weekend when staffing was at a minimum) the reference laboratory reported the following results:

  • Antibodies identified: anti-Jk
    • antibody is weak and reacts only with cells that are from donors who are homozygous for Jkand type as Jk(a+b-)
    • Note that antibodies in the Kidd system are often involved in delayed hemolytic transfusion reactions because they tend to deteriorate rapidly both in vivo and in vitro (during storage).
  • Patient phenotype: Jk(a-b+)
  • Donor phenotypes: Five of the transfused donor units were Jk(a+b+); one was Jk(a-b+)
  • Screen cell phenotypes:
    • Screen Cell I: Jk(a-b+)
    • Screen Cell II: Jk(a+b+)
    • Screen Cell III: Jk(a+b-)

The reference transfusion service then requested STAT follow-up samples to investigate SJ for a possible hemolytic transfusion reaction.