This document discusses the Kell blood group system, which is clinically significant for transfusion medicine after ABO and Rh. It has 32 antigens that can cause hemolytic disease of the fetus and newborn as well as transfusion reactions. The Kell blood group system involves antigens on red blood cells determined by genes on chromosome 7. The protein forms complexes with other proteins and has glycosylation sites. Five sets of high-incidence and low-incidence antigens exist. Those with the null phenotype lack all Kell antigens. Testing donors can help ensure safe transfusions by matching these antigens.

2. Kell blood group system genotyping in blood
donors from Tehran transfusion center
• Supervisor : Dr Kamran Moosavi
• Consultant : Dr Majid Shahabi
• Presenter : Maryam Pourshadloo

3. Significance of this survey
• After ABO and Rh ; most immunogenic ; most clinically significant in
transfusion medicine
• 32 antigen : high frequency and low frequency
• Glycoprotein hemolytic disease of the fetus and newborn (HDFN )
immediate and delayed hemolytic transfusion
reaction ( HTRs )
• Individuals with Knull phenotype require Knull phenotype for
transfusion

4. history
• Discovered in 1946
• Mrs. Kelleher anti- kell antibodies HDN
• Until now 32 antigens
• Different frequency in different populations

5. Kell antigen system
• group of antigens on the human red blood cell surface
• important determinants of blood type
• targets for alloimmune diseases and autoimmune

6. Gene
• on chromosome 7, at 7q33
• 19 exons
• more than 21 kbp of genomic DNA
• highly polymorphic SNP single amino acid substation
Kell 1 and Kell2 N 518
aa 193

7. Protein
• type II trans membrane glycoprotein
• 732 amino acids 47 N-terminal cytoplasmic
20 transmembran
665 C-terminal extracellular
• Extracellular domain 5 N- glycosylation sites
15 cysteine residues disulphide bound and
folding

8. Protein
• Covalently links via a single disulfide bond to the XK membrane
protein
• XK gene is on the short arm of the X chromosome
• All but two ( Jsa and JSb ) of the Kell antigens are localized in the
N-terminal half of the protein before residue 550

10. antigens
five sets of high-incidence and low-incidence antigens
• K and k
• Kpa, Kpb, and Kpc
• Jsa and Jsb
• K11 and KI7
• K14 and K24

11. Null phenotype
• K0 in which RBCs lack all Kell antigens
• healthy but produce anti-Ku when they encounter RBCs that do
express Kell antigens
• K0 individuals transfused with K0 blood products

12. McLeod syndrome
• Absence of XK
• Kell antigens weakly expressed
• Abnormal RBC with spiky projections
• chronic granulomatous disease (CGD)
• neurological defects

13. Kell antibodies
• K antigen most immunogenic Transfusion reactions
Hemolytic disease of the fetus and
newborn
• usually of the antibody class IgG ; predominantly IgG1
• Transfusion reaction ; HDN ; neonatal anemia
• Bacterial infections ( mycobacterium ) IgM

14. Kell antibodies
• K antigen appears on fetal red cells earlier than Rh proteins
• Anti-K facilitates phagocytosis before the cells produce hemoglobin
• Anemia is severe ; anti-K cause a suppression of erythropoiesis rather
than the immune destruction that occurs with anti-D

15. Propose of this survey
Recognizing Kell blood group system genotype in blood donors from
Tehran transfusion center