MAJOR BLOOD GROUPS

Lewis System

• The Lewis gene (Le) is responsible for producing fucosyltransferase enzyme
• Lewis antigens are produced by tissue cells.
• Commonly referred to as plasma antigens
• They are found in plasma and saliva
• Not well developed at time of birth
• Erythrocytes acquire Lewis phenotype through adsorption from plasma
• Lewis antigens are not true blood group antigens, because the erythrocytes acquire Lewis phenotype through adsorption from plasma
• Lewis antigens differ from other blood groups because they are soluble
• Lewis antigens in secretions are glycoproteins, while those in plasma are glycolipids
• The Leb antigen serves as a receptor for Helicobacter pylori
• Helicobacter pylori is associated with gastritis, peptic ulcer disease, gastric carcinoma, and Norwalk virus
• Expression is influenced by the Secretor (Se) gene, which determines secretor status and produces water-soluble blood group-specific substances, and H gene, which produces the ability to secrete H antigen
• The Lewis positive gene (Le) converts precursor material to Lea substance
• Lewis negative gene (le) cannot convert the precursor material to Leb substance
• Individuals with the genotype lele will not produce any Lewis antigen, resulting in Le (a-b-) phenotype
• Individuals with at least one Le gene and sese genes will test as Le (a+ b-)
• Individuals who inherit at least one Le gene and one Se gene will be Leb positive, testing Le (a-b+)

Lewis Antibodies

• Lewis antibodies are naturally occurring IgMs
• They activate the complement system which can cause in vitro and in vivo hemolysis
• Hemolysis is sometimes observed in vitro, particularly when fresh serum is used
• Anti-Lea efficiently binds complement
• Neutralization techniques use commercially prepared Lewis substance to confirm presence or eliminate reactions, useful when identifying other antibodies
• The Lewis system phenotypes and frequencies in whites are: Le (a+b-) at 22%, Le(a-b+) at 72%, Le(a-b-) at 6%, and Le(a+b+) Rare.
• The Lewis system phenotypes and frequencies in blacks are: Le (a+b-) at 23%, Le(a-b+) at 55%, Le(a-b-) at 22%, and Le(a+b+) Rare.

MN Antigens

• MN antigens are found on glycophorin A
• MN antigens differ in amino acid residues at positions 1 and 5
• M antigen has serine at position 1 and glycine at position 5
• N antigen has leucine at position 1 and glutamate at position 5
• M & N antigens are well-developed at birth
• M and N are codominant alleles used in paternity testing
• M & N antigens are easily destroyed/removed by enzymes

Anti-M

• Most Anti-M are naturally occurring, cold-reactive saline agglutinins
• IgM or IgG antibodies
• Do not react with enzyme-treated red cells
• Some are pH-dependent, reacting best at pH 6.5
• Other examples react only with red cells exposed to glucose solutions
• Rarely cause hemolytic transfusion reactions or HDN

Anti-N

• Anti-N are Cold-reactive IgM or IgG saline agglutinins
• Do not bind complement
• Implicated only in rare cases of HDN
• Seen in renal patients dialyzed with formaldehyde-sterilized equipment

Lectins

• Anti-M lectin is produced from the plant Iberis amara
• Anti-N lectin is produced from the plant Vicia graminea

Ss Antigens

• Located on glycophorin B
• Amino acid at position 29 determines antigen expression
• S has methionine at position 29
• s has threonine at position 29
• Well developed at birth
• Less easily degraded by enzymes
• Variable effect from ficin treatment

U Antigen

• Located near the membrane
• Always present when S or s is inherited
• Resistant to ficin

Anti-S and Anti-s

• Most examples are IgG, reactive at 37°C and the antiglobulin test phase
• Implicated in severe hemolytic transfusion reaction with hemoglobinuria and HDFN

Anti-U

• Rare, but can be formed in S-s- individuals
• Typically IgG
• May cause severe and fatal HTRs and HDN

GPA- and GPB- Deficient Phenotypes

• Individuals with En(a-) phenotype appear to be M-N- and produce anti-Ena
• Individuals with U- phenotype have RBCs that type S-s-U- and can make anti-U in response to transfusion/pregnancy. Typically IgG and is reported to cause severe and fatal HTRs and HDN

P Blood Group System

• Introduced in 1927 by Landsteiner and Levine
• Injected rabbits with human RBCs to produce anti-P
• Anti-P divided human RBCs into two groups: P+ and P-
• Phenotype P1: P, P1, pk Antigens, no antibody
• Phenotype P2: P and Pk antigens, Anti-P1 antibody
• Phenotype p: no antigens, Anti-PP1pk antibody
• Phenotype P1k: Pk and P1 antigens, Anti-P antibody
• Phenotype P2k: Pk antigen, Anti-P antibody and Anti-P1 abtibody

P Antigens

• The antigens formed are P1, Pk and P which is the Parvovirus B19 receptor
• The P antigen is present on 79% of red cells
• Individuals lacking P are termed P2
• Individuals lacking P1, Pk and P antigens are termed Pnull or p

P1 Antigen

• Found on fetal red cells as early as 12 weeks, weakens with gestational age
• Deteriorates rapidly on storage
• P1-like antigen is found in plasma, droppings of pigeons and turtledoves and the egg white of turtledoves
• P1 substance is in hydatid cyst fluid, extracts of Lumbricoides terestris and Ascaris suum

P Antibodies

• Anti-P is an IgM that has never caused HDFN but has occasionally caused a transfusion reaction
• In transfusion, recipients with anti-P1 must be given P1 negative units

Anti-P1

• Common, naturally occurring IgM antibody in the sera of P2 individuals
• Cold reactive saline agglutinin
• Strong anti-P1 is observed in individuals infected with Echinococcus granulosus
• Associated with fascioliasis, Clonorchis sinensis and Opisthorchis viverrini infections

Anti-PP1Pk

• Originally called anti-Tja
• Predominantly IgM, sometimes IgG
• Reacts over a wide thermal range
• Associated with spontaneous abortions in early pregnancy

Anti-pk

• Isolated from some examples of anti-PP1Pk by selective adsorption with P1 cells
• It has been reported in the serum of P1 individuals with biliary cirrhosis and autoimmune hemolytic anemia

Anti-P

• Naturally occurring alloantibody of all Pk individuals

Alloanti-P

• Rarely seen in the blood bank
• Significantly hemolytic in transfusion with a wide thermal range of reactivity

Autoanti-P

• Specificity is found as an IgG autoantibody in patients with Paroxysmal Cold Hemoglobinuria (PCH)
• PCH is a rare autoimmune disorder with hemolysis and hematuria with exposure to cold
• The antibody is biphasic and proven with the Donath-Landsteiner Test

Donath-Landsteiner Test

• It uses three sets of test tubes, labeled A1-A2-A3, B1-B2-B3, C1-C2-C3, with serum incubated at temperatures with group O RBCs expressing the P antigen
• Tubes 1 and 2 of each set contain 10 drops of patient serum
• Tubes 2 and 3 of each set contain 10 drops of fresh normal serum as a complement source
• Add one volume af 50% suspension of washed P+ RBCs is added to each tube, and all tubes are mixed

I (027) Blood Group System

• I is a public antigen
• i antigen is found on cord blood cells
• At birth, infant red cells are rich in i; I is almost undetectable
• During the first 18 months of life, i slowly decreases as I increases
• Adult red cells are rich in I and have only a trace amount of i antigen
• By 1½-2 years old, the child will have mostly I antigen

Rare i Adult or I Negative Phenotype

• Individuals who do not change their i status after birth
• Associated with HEMPAS

HEMPAS

• Hereditary Erythroblastic Multinuclearity with Positive Acidified Serum
• Increased i
• Decreased H
• Decreased sialic acid

Antibodies

• Autoanti-I is a cold agglutinin present in low titers in healthy adults and is Common
• Can be a benign/pathologic antibody
• Demonstrates strong reactions with adult cells, weak reactions with cord cells
• High titers are seen during/following infections with Mycoplasma pneumonia, in elderly with autoimmune hemolytic anemia and patients with cancer of the reticuloendothelial system (RES)
• Not associated with HDN because the antigen is poorly expressed on infant red cells

Types of Anti-I

• Benign Anti-I found in serum of many normal healthy individuals
• Not associated with in vivo red cell destruction and Weak
• Naturally occurring, saline-reactive IgM agglutinin
• Usually reacts at 4°C

Pathologic Anti-I

• Potent IgM agglutinins with higher titers and broader thermal range of activity, reacting up to 30°C or 32°C
• Attach in vivo; cause autoagglutination and vascular occlusion or intravascular hemolysis

Anti-i

• Most autoanti-i are IgM
• Reacts best with saline-suspended cells at 4°C
• Potent examples are associated with INFECTIOUS MONONUCLEOSIS/Epstein-Barr virus infections and some lymph proliferative disorders
• In Ab detection Anti-I Adults cells react strong cord cells weak
• In Ab Detection Anti-i Adult cells react weak cord cells strong

Anti-IT

• Benign IgM Anti-IT frequently found in Melanesians and the Yanomama Indians in Venezuela
• Examples of IgM and IgG anti-I" reacting preferentially at 37°C have also been found in patients with warm autoimmune hemolytic anemia, with a special association with Hodgkin' disease

Kell (006) Blood Group System

• Immunogenic, K is rated second only to D in terms of immunogenicity.
• Well-developed at birth
• Expression very weak on McLeod phenotype cells
• Kell1: K antigen, Kell
• Kell2: k antigen, Cellano
• Kell3: Kpa antigen, Penney
• Kell4: Kpb antigen, Rautenberg
• Kell6: Jsa antigen, Sutter
• Kell7: Jsb antigen, Matthews

Mode of Inheritance

• it is assumed precursor substance Kx, is coded by a gene X1k on the X chromosome
• Kx precursor gets converted to the appropriate gene products of the inherited Kell genes

McLeod Phenotype

• Lack of Kx with abnormal erythrocytes (acanthocytes) which are prematurely destroyed and cause chronic hemolytic anemia

Chronic Granulomatous Disease

• lack of leukocytic Kx

Kell Null (K0)

• RBCs lack expression of all Kell antigens
• Phenotype is rare

Anti-K

• Common antibody encountered in blood bank
• IgG antibody reactive in the antiglobulin phase
• It is Made in response to antigen exposure through pregnancy and transfusion
• Severe hemolytic transfusion reactions are implicated
• Associated with severe hemolytic disease of the newborn

Duffy (008) Blood Group System

• Duffy gene is the first human gene to be assigned to a specific chromosome
• There’s Fya and Fyb antigens which are antithetical antigens that appear on cord blood cells
• It has been Identified on fetal red cells as early as 6 weeks gestational age and they are developed at birth
• They are Destroyed by common proteolytic enzymes, sensitive to ficin or papain treatment
• Its Receptors for Plasmodium vivax and Plasmodium knowlesi

Fy3

• Expresses on cord blood cells
• Resistant to ficin or papain treatment
• red cells that are Fyla-b-) are also Fy:-3

Fy5

• Expresses on cord blood cells
• Resistant to ficin or papain treatment
• Its common in Whites
• Altered expression in Rhnull phenotype; possible antigen interaction between Duffy and Rh proteins

Fy6

• It expresses on cord blood cells
• Sensitive to ficin or papain treatment
• red cells that are Fyla-b-) are also Fy:-6
• The antigen has been defined by murine monoclonal antibodies; no human anti-Fy6 has been described

Ry (a-b-) RBCs

• Resist infection by Plasmodium vivax and knowlesi
• Predominant in people coming from West Africa

Duffy Antibodies

• Anti-Fya and anti-Fyb antibodies are usually IgG and react best at the antiglobulin phase
• activity is enhanced in low ionic strength medium
• They do not react with enzyme-treated red cells
• They are Associated with HTRs, although hemolysis is not often harsh, occasionally causes severe HDEN
• Anti-Fya is more commonly observed than anti-Fyb

Kidd (009) Blood Group System

• Jka and Jkb Antigens, which are Well-developed at birth, and are Not altered by enzymes

JK (a-b-)

-Resist lysis in 2M urea
-Made up of a solution commonly used to lyse RBCs in a sample before it is used in some
Automated platelet counting instruments

People with the null phenotype are lacking Jka, Jkb, and the common antigen Jk3. Very rare, most abundant among Polynesians, identified in Filipinos, Indonesians, Chinese, and Japanese. Alloanti-Jk3 is an IgG antiglobulin reactive antibody that resembles and acts like an inseparable anti-Jk-Jk'. It will cause the individual making the antibody to type Jk (a-b-).

Anti-Jka and Anti-Jkb Antibodies have

• A very bad reputation in the blood bank
• Are Immune antibodies, from in response to pregnancy or transfusion
• The ability to get detected in the antiglobulin test
• Are made more severe by using ENZYMES, LISS and PEG which enhance IgG attachment
• are a common source for hemolytic transfusion reactions, (DELAYED ones,) However in some severe cases intravascular hemolysis has been noted. Usually Extravascular hemolysis notes however
• A very uncommon source for HDN, but it still happens!

Lutheran Blood Group System

-Recognized in 1945 -Anti Lua was first discovered due diffuses, following the transfusion of a unit of blood carrying the corresponding low incidence antigen.

• The new antibody was named Lutheran
• The Donors name Luteran was confused with the actual antigen resulting in it being named completely wrong.
• Has been found on fetal RBC between 10-12 weeks
• Antigens are Poorly developed

Anti-Lua

• IgA, IgM or IgG
• Naturally-occurring saline agglutinins that react best at room temperatures
• Few react at 37°C by indirect antiglobulin test

Anti-Lub

  -Most are IgG however IgM and IgA antibodies have been seen
  -Reacts at 37°C and works with the antiglobulin phase
  -Made in response to pregnancy or transfusion
  -is a cause for transfused cells in shortened survival, and post-transfusion Jaundice

Dosage Effect

-When stronger agglutination is found with homozygous genes

Enzyme Technique

Different Enzymes which help with Blood grouping etc include: -Papain which comes from Papaya seeds -Bromelin which is made From Pineapple core -Ficin, comes from Fig plants -Trypsin which is made from Pig stomach

Blood Groups with Enhancment vs with No effect from treatment of Test Cells:

Rh, Lewis, Kidd, P1 help ENHANCE BY ENZYME TREATMENT OF TEST CELLS M, N, Duffy are NOT Detectable

Other Test Results

The chart gives quick tips and test results

Final Thoughts

• Know the Most Common Causes and reactions from different immune disorders*

Check Point Questions

• There are a list of questions here for people to self test*