Mrs. A.L., a 91-year-old female, was admitted for left hip surgery on April 2. Two units of RBC were ordered for her surgery. She had a history of three prior pregnancies and two units of RBC 9 years ago with no adverse reactions.


  • Group A Rh negative
  • Antibody screen negative by PEG-IAT
  • Transfused with two units of RBC without incident


Antibody Screen and Crossmatch Results

  • Group A Rh negative
  • Antibody screen positive by PEG-IAT
  • Incompatible with one of two donors - both later typed as Jk(a+)
  • Autocontrol weak positive

Antibody Identification (Plasma)

  • Probable anti-Jka reacting only with Jk(a+b-) cells. Anti-E and anti-K not excluded.

Transfusion Reaction Investigation

  • Weakly positive DAT with IgG and C3d sensitizing the red cells
  • No hemolysis or icterus in post-transfusion specimen

Patient Phenotypes

  • Rh negative (rr) Jk(a-) K-
  • Antigen typing possible as transfusion occurred 12 weeks ago
  • Jka typing done on CDP-treated red cells; K typing done using monoclonal IgM antisera

Antibody Identification (Eluate)

  • Probable anti-Jka reacting with both Jk(a+b-) and Jk(a+b+) cells

Antibody Exclusions (Plasma)

  • Anti-E and anti-K are excluded.

Post-investigation Crossmatch Results

  • Mrs. A.L. was crossmatched by PEG-IAT with two units of Jk(a-) RBC.
  • Both units were compatible and transfused without incident.
  • Mrs. A.L. was discharged following surgery.

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