LQCL2616 - CMLE - Anti-Kpᵇ Alloantibody: A Case Study in Multidisciplinary Hospital Collaboration-LQCL2616

LQCL2616 - Educational Activity

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This document reviews the Kell (KEL) blood group system and uses a case study to illustrate the clinical and operational challenges of managing antibodies to high-prevalence antigens, particularly anti-Kpb. The KEL system (ISBT 006) is one of the most clinically significant blood group systems after ABO and Rh, comprising 38 antigens expressed on the CD238 red cell membrane glycoprotein. Kell antigens are highly immunogenic, and antibodies are typically IgG, persistent, and clinically significant because they can cause hemolytic transfusion reactions and hemolytic disease of the fetus and newborn; therefore, antigen-negative blood is recommended whenever feasible.<br /><br />The case involves a 61-year-old man with acute myeloid leukemia and known anti-Kpb who required frequent transfusions due to chemotherapy-related cytopenias. Because Kpb (KEL4) is present in >99.9% of the population, Kpb-negative units are extremely rare and often stored frozen for special need. The patient’s antibody screen remained reactive, creating concern for additional clinically significant alloantibodies masked by the strong anti-Kpb.<br /><br />To aid antibody identification, the blood bank used dithiothreitol (DTT)-treated reagent red cells, which disrupt disulfide bonds and denature Kell antigens, eliminating anti-Kpb reactivity and allowing rule-outs of other antibodies. The document explains that DTT also affects several other blood group systems and requires quality control (eg, loss of Kell reactivity with preserved controls) and special transfusion considerations (eg, providing K-negative units when Kell status cannot be confirmed).<br /><br />After transfer to a smaller cancer center supported by a community hospital blood bank lacking DTT capability, a multidisciplinary collaboration was developed: screening-cell aliquots were sent to a tertiary hospital for DTT treatment and returned for local testing, while Kpb-negative frozen RBCs were ordered in advance. This coordinated approach enabled timely, safe weekly transfusions despite limited local resources.

Keywords

Kell blood group system (KEL)

anti-Kpb antibody

high-prevalence antigen antibodies

Kpb-negative red blood cell units

dithiothreitol (DTT) treatment

antibody identification and rule-outs

hemolytic transfusion reaction risk

hemolytic disease of the fetus and newborn (HDFN)

acute myeloid leukemia transfusion support

multidisciplinary blood bank collaboration