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Transfusion Medicine

Kidd Blood Group System

The Kidd blood group system is a collection of glycoprotein antigens on the surface of red blood cells responsible for the urea transport and maintaining the osmolarity of red blood cells. This activity describes the role of the Kidd blood group system in improving the knowledge of clinicians, researchers, technicians, and other healthcare providers dealing with transfusion-related activities. This activity empowers healthcare professionals to understand the basic genetics of the SLC14A1 gene, t

v1 · Reviewed Nov 7, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • The antibodies against Kidd antigens are of the complement binding type and can lead to intravascular and extravascular hemolysis.
  • The clinically significant antibodies against the Kidd blood group system can cause acute and delayed hemolytic transfusion reactions in fetuses and newborns after transfusion and hemolytic disease.
  • Anti-Jka antibodies are responsible for mild-to-severe immediate HTRs and are regularly associated with delayed HTRs, which may lead to oliguria, renal failure, and even death.
  • Anti-Jkb is also implicated in causing severe acute and delayed reactions.
  • Kidd antibodies have been shown to cause aggressive acute and hyperacute kidney transplant rejections, possibly due to the structural similarity between urea transporters and Kidd antigens.
  • The Kidd blood group system has 3 major antigens—Jka, Jkb, and Jk3.
  • A screening method for identifying individuals with the Kidd null phenotype involves delayed lysis of their RBCs in a 2M urea solution.
  • Direct and indirect antiglobulin tests are also used to detect specific antibodies against Kidd antigens in serum or plasma.
  • Polymerase chain reaction (PCR) is a highly sensitive molecular technique used to amplify specific DNA sequences associated with Kidd antigens.
  • Microarray technology enables simultaneous analysis of multiple blood group antigens, including those in the Kidd system.
  • Sanger sequencing can be used to analyze exons and intron-exon borders of the Kidd gene, providing comprehensive information about mutations and polymorphisms.
  • The healthcare staff must check for an additional Kidd antigen-negative blood unit with all mandatory pretransfusion checks during the planning of transfusion in patients with Kidd antibodies.
  • Implement interprofessional team strategies to improve transfusion outcomes in patients with Kidd antibodies.
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  • Antibodies to the Kidd system may cause both acute and delayed hemolytic transfusion reactions, but most reported reactions are delayed types.
  • Anti-Jka is involved in over one-third of delayed hemolytic transfusion reactions (HTRs).
  • Anti-Jkb is also implicated in causing severe acute and delayed reactions.
  • Anti-Jk3 may be formed if Kidd null patients are transfused with either of Jk(a+b−), Jk(a−b+), or Jk(a+b+) phenotypes.
  • Kidd antibodies have been shown to cause aggressive acute and hyperacute kidney transplant rejections, possibly due to the structural similarity between urea transporters and Kidd antigens.
  • Kidd antigens may be responsible for causing alloimmunization in pregnant females, but the hemolytic disease of the fetus and newborn is typically mild, even with the presence of a very high titer, and only a few cases are reported.
  • A few cases of passenger lymphocyte syndrome are caused by anti-Jka antibodies following peripheral blood progenitor cell and liver transplantation in the follow-up phase, where they can be mild to severe and can lead to hemolysis.
  • These antibodies are often involved in delayed hemolytic transfusion reactions as their level becomes undetectable with time and then rapidly increases upon re-exposure to Kidd antigens.
  • Kidd antibodies are detected most commonly within a month of transfusion, but their levels decline rapidly and sometimes become undetectable after 3 months.
  • These antibodies can show a strong anamnestic response when re-sensitized.
  • Approximately 40% to 50% of sera with Kidd antibodies bind complement; these antibodies are sometimes only detectable in the antiglobulin test using polyspecific antiglobulin or anti-complement.
  • During transfusing blood products, nurses and clinicians should be proficient in promptly identifying transfusion reactions and possible complications while implementing close monitoring and preventive strategies to handle adversities.
  • Further research should be conducted on the role of the SLC14A1 gene and its functional protein in various diseases, along with the transfusion outcomes and its clinical sequelae.
  • review
    Kidd Blood Group System. StatPearls [Internet] — Apoorva Maheshwari, Muhammad Zubair, Ashish Maheshwari — StatPearls Publishing, 2025

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov