Transcript of this ppt
Kidd blood grouping
Learning outcomes
• At the end of this lecture students will be able to learn:
• Introduction to Kidd blood group
• Why it is called as Kidd/Historical background ?
• Kidd antigens (Kidd glycoprotein)
• Clinical significance of Kidd antibodies
Introduction
• The Kidd antigens are normally expressing in every individual
• These antigens are glycoproteins which are present in RBC and kidney
• These antigens play an important role in maintaining osmotic stability & shape of RBC.
• It helps the kidney to produce concentrated urine
• People who do not produce the Kidd glycoprotein tend not to be able to maximally concentrated urine
• but despite this, they are healthy and their RBCs have a normal shape and lifespan.
Historical background
• In 1951 a girl called as Mrs. Kidd was found to have antibodies against an unknown red cell
antigens during her pregnancy
• The marker was present on the fetal RBC
• The maternal antibodies targeted against it caused fatal hemolytic disease in her newborn child
• The protein was given the name Jka
• And was the first antigen to be discovered in the Kidd blood group system
• Since at This time two other antigens called as Jkb and Jk3 have been found
• In 1959, the first example of the null phenotype, i.e., Jk(a-b-), was found in a woman who had become jaundiced after a blood transfusion.
Kidd protein /antigens
• The SLC14A1(Solute carrier family 14, member 1) gene encodes the Kidd glycoprotein
• This gene is member of urea transporter and present on ch18 and composed of 11 exons
• The first three exons aren’t translated mean 4-11 form the mature Kidd protein
• The Jka and Jkb antigens are the products of two alleles that are inherited in a co-dominant fashion
• The Jk(a-b-) phenotype is generally inherited as a recessive trait—a number of different
mutations have been found to be responsible
• Due to splice site mutation the JK-null cant be transported to RBC membrane
• ISBT has given the symbol for Kidd antigens as JK
• There are total of three antigens in Kidd blood group system
• Three most common phenotypes
• And the fourth one which isn’t that common is Jk-null phenotype
Table:
Antigens Phenotypes
Jka JK(a+b-)
Jkb JK(a-b+)
Jk3 JK(a+b+)
Jk-null phenotype, JK(a-b-)
Jk-null phenotype
• JK(a-b-) is a rare phenotype in most of the populations
• Subjects with this blood type are often detected after they have been immunized with previous
blood transfusion history or pregnancy
• After immunization, JK(a-b-) individuals form anti-Jk3
• which can cause HDN in subsequent pregnancies
• Also it can hemolyze donor blood that contains Jka and/or Jkb antigens during a subsequent blood transfusion.
Clinical significance of Kidd antibodies
• The Kidd antibodies are often difficult to detect
• Making them hazardous in blood transfusion,
• Where they are suspected to be a common cause of delayed hemolytic transfusion reactions(DHTRS)
Table:
Antibodies causing HTRS Antibodies causing HDN
1/3rd Anti-Jka causes severe Anti-Jka rarely causes
DHTRS
anti-Jkb also causes severe DHTRS Anti-Jkb rarely causes
Anti-Jk3 causes both immediate Anti-jk3 also causes rarely
and delayed HTRS
HTRS: hemolytic transfusion reactions
HDN: hemolytic disease of new born
References
• Reid ME and Lomas-Francis C. The Blood Group Antigen Facts Book. Second ed. 2004, New York:
Elsevier Academic Press.
• Matson G A , Swanson J , Tobin J D . Severe hemolytic disease of the newborn caused by anti-
Jka. Vox Sang. 1959;4:144–7 (PubMed)
• https://www.ncbi.nlm.nih.gov/books/NBK2272
• https://pubmed.ncbi.nlm.nih.gov
• Blood group and red cell antigens book by Laura Dean
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