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Other Blood Groups Lewis, Kell, Duffy, Kidd, Ii, MNSs & P

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Presentation on theme: "Other Blood Groups Lewis, Kell, Duffy, Kidd, Ii, MNSs & P"— Presentation transcript:

1 Other Blood Groups Lewis, Kell, Duffy, Kidd, Ii, MNSs & P

2 Introduction Over 500 blood group antigens
“High incidence”, “public” or “high frequency” antigens are those present on almost every person’s red blood cells “Low incidence”, “private” or “low frequency” antigens are present on very, very few individuals red blood cells

3 Introduction Each known antigen initially identified through the detection of its specific antibody in the serum. Knowledge of serologic behavior and characteristics of blood group antibodies is CRITICAL for identification

4 Introduction Essential when evaluating antibody screen and panel studies. Considerations given to: Phase of reactivity Antibody class involved Ability to cause HDFN and HTR

5 Major Blood Group Systems
Lewis I P MNSs Kell Kidd Duffy

6 Lewis System Major antigens Lea and Leb , other antigens include Lec, Led and Lex Antigens ARE NOT intrinsic to RBCs but are absorbed from the plasma and inserted into RBC membrane.


8 Lewis System Antigenic Development
Genetic control reside in single gene “Le” Amorph le, if homozygous will not have Lewis antigens Lea formed first, then modified to form Leb which is adsorbed preferentially over Lea Lewis phenotype of RBC can be changed by incubating with plasma containing Lea or Leb glycoplipid.

9 Lewis System Lewis Phenotypes and Their Frequencies White Black
Le (a+b-) 22% 23% Le (a-b+) 72% 55% Le (a-b-) 6% Le (a+b+) Rare rare

10 Lewis System Lewis antigens in infants
Antigens absent or extremely weak at birth Expression of Leb gradual Birth Le (a-b-) 2 months Le(a+b-) 12 to 18 months Le(a+b+) 2 to 3 years Le (a-b+)

11 Lewis System Lewis antigens and pregnancy
Antigen strength may decline dramatically Transiently Le (a-b-) may produce Lewis antibodies during pregnancy Antigens return after delivery and antibodies disappear

12 Lewis System Interaction of Le, Se and H Genes
lele will not have Lewis antigens, but if Se present will have A, B and H in secrections Genotype se/se and have one Lewis antigen will have Lea in their secretions but no A, B or H.


14 Lewis System Le (a+b-) Le (a-b+) Le (a-b-) Lewis Phenotype
ABH Secretor Lewis Secretor Le (a+b-) All ABH NON-Secretors All Lea Secretors Le (a-b+) All ABH secretors All secretors of Lea and Leb Le (a-b-) 80% ABH secretors 20% ABH NON secretors NONE

15 Lewis System Lewis Antibodies
Almost always IgM, react strongly at RT, may cause ABO discrepancy if reverse cells have Lewis antigen. Occur almost exclusively in Le (a-b-) and production of anti-Lea AND –Leb not unusual Anti-Lea frequently encountered, anti-Leb rarely encountered.


17 Lewis System Lewis Antibodies
Although most react at RT reactivity may be seen at 37C, but is weaker and may be weakly reactive at AHG Can bind complement and cause IN-VITRO hemolysis, most often with enzyme treated cells Because antibodies are IgM and antigens are poorly developed at birth antibodies NOT implicated in HDFN.


19 Lewis System Lewis antibodies
Can be neutralized in-vitro by additions of Lewis Substance Le antigens are present in secretions Add to serum with Lewis antibodies and the antibodies will be bound to the soluble Lewis antigens Useful when multiple antibodies are present and 1 is a Lewis, eliminates the activity of the antibody

20 Lewis Antibodies Anti-Le a, Anti-Le b, Anti-Lex
Most react at room temperature or below - Often fix complement Some in vitro hemolysis Le a may cause HTR

21 Lewis Antibodies Anti-Le a Found in Lea-b- secretors
best room temperature or below Often fix complement Some in vitro hemolysis Le a may cause HTR

22 Lewis Antibodies Anti-Le b Often found with Anti-Lea
Most react at room temperature or below Two types - Anti-LebH and Anti-LebL Rare cause of HTR

23 Lewis Antibodies Anti-Lex Most react at room temperature or below -
Reacts with both Lea and Leb as a single antibody

24 Lewis Antibodies Special Problems in the Blood Bank
Lewis antigens may be weaker during pregnancy and women produce antibodies Can neutralize Lewis antibodies with Lewis plasma Pregnant woman with room temperature antibodies, neutralize with Lewis antigen when testing for HDN antibodies

25 Lewis System Transfusion Practice
Transfused RBCs will acquire the Lewis phenotype of the recipient within a few days Lewis antibodies in patient will be neutralized by Lewis substance in donor plasma Lewis antibodies rarely cause in-vivo hemolysis It is not necessary to phenotype donors for Lewis antigens prior to transfusion, give crossmatch compatible

26 The Kell Blood Group System

27 Background information
The Kell blood group system was discovered in 1946. Number of Kell antigens: > 20 These antigens are the third most potent, after those of the ABO and Rh blood groups, at triggering an immune reaction.

28 Molecular information
The KEL gene is found on chromosome 7 The KEL gene is highly polymorphic, with different alleles at this locus encoding the 25 antigens that define the Kell blood group. The Kell protein is a polypeptide chain of 732 amino acids in length that becomes glycosylated at five different sites. It makes a single pass through the RBC membrane.


30 Kell Blood Group System
XK gene produces Kx substance, which is a precursor of of Kell Ags Kel genes convert Kx substance into the Kell Ags on RBCs K (Kell) & k (cellano) are produced by allelic genes, this results into 3 phenotypes: K+k- (genotype KK) K+k+ (genotype Kk) K-k+ (genotype kk) Other allelic genes include: Kpa/Kpb, Jsa/Jsb

31 XK Gene (Chromosome X) KEL Gene RBC Kx
Kell system glycoprotein: Kell Ag’s reside here. Kx

32 Frequency of Kell phenotypes
Caucasians Blacks K-k+ 91 % 98 % K+k- 0.2 % Rare K+k+ 8.8 2

33 Kx Substance Kx substance is present on RBCs & WBCs
Kell genes convert Kx substance into the Kell Ags on RBCs Kell genes do not convert Kx on WBCs

34 McLeod Phenotype Absence of Kx proteins in RBCs membrane lead to McLeod Phenotype This absence cause: abnormal RBCs shape (acanthocytes) & reduced in-vivo survival

35 Chronic Granulomatous Disease
Absence of Kx proteins in WBCs cause CGD Leukocytes are able to phagocytose but not to kill bacteria Patients with CGD have recurrent bacterial infections Patients who lack Kx on RBCs & WBCs have both Mcleod and CGD cells of the immune system have difficulty forming the reactive oxygen compounds (most importantly, the superoxide radical) used to kill certain ingested pathogens


37 Kell Null (K0) Phenotype
1. K0 is a silent Kell allele 2. When homozygous K0K0 inherited no Kell system antigens are expressed. 3. Kx antigen expression is enhanced 4. Very rare Kx

38 Kell Antibodies K- individuals produce anti-K when exposed to K+ cells
Frequency of K+ is low (9%), easy to find blood On the other hand frequency of k is 99.9% k- individuals produce anti-k when exposed to k+ cells Difficult to find blood

39 Antibodies produced against Kell antigens
Kell Abs Clinically Significant Yes Abs class IgG (rarely) IgM Thermal range 4 - 37 HDNB Transfusion Reactions Extravascular Intravascular Rare HDN: Antigen is present on fetal cells as early as 10 weeks gestation

40 Duffy Blood Group System

41 Duffy Blood Group System
The Duffy blood group was discovered in 1950. The Duffy glycoprotein is encoded by the FY gene, found on chromosome 1 , of which there are two main alleles, FYA and FYB. They are codominant. The Duffy gene codes for a glycoprotein also found in other tissues: brain, kidney, spleen, heart and lung. The Duffy glycoprotein is a transmembrane protein Five alleles at Duffy locus, the most important: Fya, Fyb & Fy (Silent Allele) Fya is more immunogenic than Fyb


43 Duffy Antigens 65 49 18 Phenotype Frequencies Phenotype Caucasians %
Blacks % Fy (a+b+) 49 2 Fy (a+b-) 18 14 Fy (a-b+) 33 19 Fy (a-b-) rare 65

44 Different genes Fy(a-b-) blacks do not produce anti-Fya or anti-Fyb following transfusion with Fy(a+) or Fy(b+) blood Fy(a-b-) Caucasians become sensitized following transfusion with Fy(a+) or Fy(b+) blood This suggest that Fy(a-b-) phenotype arises from different genes in the two populations a mutation in the promoter region of the FYB allele abolishes the expression of the Duffy glycoprotein in RBCs, but the protein is still produced in other types of cells. these patients do not generally make anti-Fyb or anti-Fya Less commonly, the Fy(a-b-) phenotype is a result of point mutation that introduces a premature stop codon into the coding sequence. It is unlikely that the truncated Duffy protein is transported to the cell surface, and it is likely that the Duffy protein would be absent from all tissues in individuals who carry this type of mutation.

45 Duffy Antigens Fya, Fyb antigens are Destroyed by enzymes
Abs DO NOT agglutinate enzyme treated cells Moderately immunogenic Fya is more immunogenic than Fyb

46 Clinically Significant Transfusion Reactions
Duffy Antibodies IgG antibodies and can activate complement Anti- Fya is more frequently encountered Anti- Fyb is more frequently found in patients produced multiple alloantibodies Duffy Abs Clinically Significant Yes Abs class IgG Thermal range 4 - 37 HDNB Transfusion Reactions Extravascular Intravascular

47 Duffy and Malaria Black people with the Duffy phenotype of Fy(a–b–) appear to have resistance to Plasmodium vivax & Plasmodium knowlesi causative agents of Malaria. Duffy antigens appear to be a receptor for the P. vivax organism and when the antigen is not present on the red blood cell membrane P. vivax is unable to access the red blood cell Some area’s of West Africa are 100% Fy(a–b–). Plasmodium falciparum binds to RBCs at integral glycophorin A & B

48 Duffy and Malaria

49 Kidd Blood Group System

50 Kidd Blood Group System
The Kidd blood group was discovered in 1950. The Kidd gene is located on chromosome 18 Three alleles: Jka, Jkb, Jk Codominant Inheritance Jk is a silent allele (amorph) The Kidd protein is an integral protein of the RBC membrane.

51 Kidd Phenotype Frequencies
Caucasians (%) Jk (a+ b-) 29 Jk (a+ b+) 49 Jk (a- b+) 22 Jk (a- b-) Exceedingly rare (COMMON IN FILIPINOS)

52 Phenotype Frequencies
What is the purpose of learning the phenotype frequencies of each blood group antigen? When crossmatches are required it helps the Tech know how many units to crossmatch or antigen type to find compatible blood. If a patient has anti-Jka antibody how many RBC units need to be antigen typed to find 2 compatible units? 78% of the population is positive for the antigen therefore 22% are NEGATIVE for the antigen. Approximately 2 out of 10 units are compatible. Need to antigen type 10 units.

53 Kidd Antigens & Antibodies
Ags are well developed at birth Have tendency to drop to low or undetectable levels following formation. Abs are of IgG type & can activate complement (Anti-Jka, Anti-Jkb ) Produced following transfusion or pregnancy Can cause HDNB They are also a very common cause of delayed HTRs


55 Ii Blood Group Found nearly on all RBCS
Their products are transferase enzymes that attach repeating units of Gal and GlcNAc to the ABO Precursor Substance. Big I gene codes for branching of the Precursor Substance.

56 Ii Antigens Little i antigen is LINEAR Big I antigen is BRANCHED
Found on cord cells, predominantly Big I antigen is BRANCHED Gradually convert from i to I during the first 18 months of life. Not all i converted to I, some i still present on adult cells, normally. Rare adult individuals termed iadult do not express i Ag on their red cells


58 The I and i antigen sites are considered uncompleted ABH active chains.
When ABH are removed from RBCs more I Ags are expressed I structure located beneath the ABH Ags

59 Clinically Significant Transfusion Reactions
I Antibodies: Anti-I Anti-I is naturally occurring often due to a Mycoplasma pneumoniae infection Anti-I reacts with all adult cells (including patient’s own, all reagent cells, all donor cells) Anti-I does not react with cord cells Auto-anti-I is a common “cold agglutinin” Anti-I Abs Clinically Significant Rare Abs class IgM Thermal range 4 - 10 HDNB No Transfusion Reactions Extravascular Intravascular rare

60 Antii Antibodies Antii is rarely found in healthy individuals
Reacts preferably with cord cells anti-i can be found secondary to Infectious Mononucleosis. Transient: Only present with active disease

61 MNSs Blood Group System
The antigens M and N are produced by co-dominant alleles closely linked to the S and s genes, which are also co-dominant.  Chromosome 4 contains these linked genes Genes produce two distinct glycophorins or sialyglycoproteins (SGP) on the RBC membrane.

62 MN Genetics MN Locus genes produce Glycophorin A (GPA)
M-GPA’s 1st five aa’s = Serine-Ser-Thr-Thr-Glycine N-GPA’s 1st five aa’s = Leucine-Ser-Thr-Thr-Glutamic acid Amino acids (aa) 2, 3 & 4 are the same for both Glycophorin A (GPA) is a glycoprotein also known as MN-sialoglycoprotein

63 MN Genetics

64 MN Genotypes & Phenotypes
Frequency % M+N- MM 30 M+N+ MN 50 M-N+ NN 20

65 MNSs Antigens M & N only differ in their amino acid sequence at positions 1 and 5 M Glycophorin A N RBC S & s only differ in their amino acid sequence at position 29 S U s Glycophorin B COOH end ….. ….5, 4, 3, 2, 1 (NH2 end)

66 Ss Genetics Ss genes code for the production of Glycophorin B(GPB)
S glycophorin B has Methionine at aa position 29 s glycophorin B has Threonine at aa position 29 Glycophorin B (GPB) is a glycoprotein also known as Ss-sialoglyprotein

67 Ss Genotypes & Phenotypes
Frequency % Caucasians Blacks S+s- SS 11 6 S+s+ Ss 44 24 S-s+ ss 45 68 S-s- Susu 2 U antigen is a high incident antigen NOT seen in individuals who lack both S and s antigens.  Individuals who lack this antigen (<1%) have a high likelihood of forming anti-U as well as anti-S and anti-s. 

68 Rare Alleles Rare low incidence alleles found on MN locus
Some may result from crossing over of genes of glycophorin A & B Such crossing over results in hybrid sialoglycoproteins

69 Clinically Significant Transfusion Reactions
Anti-M Antibodies Variability of reactivity (Dosage) Strong reactions with RBCs homozygous for MM Weak reactions with RBCs heterozygous MN Anti-M Abs Clinically Significant Seldom Abs class IgG & IgM Thermal range 4 – 22 Rare 22-37 HDNB rare Transfusion Reactions Extravascular Intravascular Rare No

70 Clinically Significant Transfusion Reactions
Anti-N antibodies Anti-N Abs Clinically Significant No Abs class IgM Thermal range 4 - 22 HDNB Transfusion Reactions Extravascular Intravascular Naturally occurring cold agglutinin Can form in patients with renal Failure During dialysis with formaldehyde sterilized equipment Formaldehyde may alter the N Ag structure making it appear foreign

71 Anti-S and Anti-s antibodies
Anti-S Abs Clinically Significant Sometimes Abs class IgG & IgM Thermal range 4 - 37 HDNB Yes Transfusion Reactions Extravascular Intravascular No Anti-s Abs Clinically Significant Yes Abs class IgG Thermal range 4 - 37 HDNB Transfusion Reactions Extravascular Intravascular No

72 P Blood Group System Genetics: These genes code for enzymes that sequentially add sugars to precursor substance. This system is related to the ABO, Le and Ii systems. Genes: P1, Pk, P and lower case p (silent allele) All antigens are expressed on glycolipids on red cells

73 Phenotypes, Detectable Antigens & Frequencies
Whites % P1 P1, P 79% P2 P 21% Pk1 P, Pk Rare Pk2 Pk p N/A Pk is the precursor of P. Rare individuals do not convert Pk into P. Those will have Pk on RBCs.

74 Clinically Significant Transfusion Reactions
Anti-P1 Antibodies Anti-P1 Abs Clinically Significant occasionally Abs class IgM Thermal range 4 – 22 Rare 22-37 HDNB NO Transfusion Reactions Extravascular Intravascular No Rare Naturally occcurring Abs found in the serum of P2 Individuals

75 Anti-P1 Antibodies

76 Allo Anti-P Antibodies
Allo Anti-P Abs Clinically Significant Yes Abs class IgM Rare IgG Thermal range 4 – 37S HDNB Rare Transfusion Reactions Extravascular Intravascular No Naturally occcurring Abs found in the serum of Pk and p Individuals

77 Auto anti-P Antibodies
It is an IgG biphasic Ab associated with Paroxysmal Cold Hemoglobinuria (PCH) Binds complement at cold temperatures and activates that complement in warm temperatures lysing the red blood cells. Auto Anti-P Abs Clinically Significant Yes Abs class IgG Biphasic Binds at 0 Hemolysis 37 HDNB Rare Transfusion Reactions Extravascular Intravascular


79 Anti Tja Antibodies Combination of anti-P, anti-P1 & anti-Pk
Found in serum of individuals who have no P, P1 & Pk Ags on red cells




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