Blood Bank: Other Blood Group Systems

• Le gene (FUT 3)

• Se gene (FUT 2)

• H gene (FUT 1)

Genes that are located on chromosome 19 (3)

Nonsecretors

Secretor status of individuals who type as Le(a+b-)

Adds fucose to N-acetylglucosamine

The Le gene codes for the production of a transferase enzyme that (——) on ABH precursor substances to form soluble Le^a Ag. This occurs only in secretions (Type 1 chain)

Se gene

Following teh action of the Le gene, the (——) enzyme adds a fucose to the same precursor substance in the secretions resulting in the formation of the Le^b Ag

Adsorbed from plasma (soluble Ags) to the membrane

(Unique property) Lewis antigens are not intrinsic to RBCs like ABO and Rh Ags, instead they are…

L-fucosyltransferase

Le gen codes for (—enzyme—), which adds fucose to type 1 chains

• LeSeH → Le^(a-b+)

• LeseH → Le^(a+b-)

• leSeH → Le^(a-b-)

• leseH → Le^(a-b-)

Given the following genes, describe the lewis phenotype:

• LeSeH

• LeseH

• leSeH

• leseH

• Glycoproteins

• Glycolipids (RBCs can only adsorb glycolipids)

Le antigens found in secretions are (——) while lewis antigens in plasma are (——)

Become Le(a-b-), but revert to original phenotype post-partum

How are Lewis antigens affected during pregnancy?

2-3 years

Correct Le phenotype may not be obtained until (——)

• Abnormal lipid metabolism

• Cancer

• Alcoholic cirrhosis

• Some infections

Loss of the Lewis Ag expression on RBCs is caused by… (4)

• IgM (rarely IgG)

• IS/RT

• Not clinically significant (unless IgG or C’ binding → hemolysis)

• When hemolysis → give Le ag neg blood (usually no hemolysis → xmat compatible)

Lewis antibody characteristics (class, phase of rxn, clinical significance, when donor must be negative)

Anti-Le^a

Which is more common, anti-Le^a or anti-Le^b?

anti-Le^bH

Antibody that reacts when both Le^b and H antigens are present

Anti-Le^bL

Antibody that reacts with Le^b regardless of ABO type

• P1PK gene

• chromosome 22

The P1 antigen is coded by the (——) gene, which is found on chromosome (——)

• GLOBESIDE gene

• chromosome 3

The P antigen is coded by the (——) gene and is found on chromosome (——)

• N-neuraminic acid

• P^k

The LKE antigen is dependent on the terminal (——) and the expression of this antigen is inversely related to the expression of (——) antigen

P₁ phenotype

(P and Glob system) 79% of the population expresses this phenotype; RBCs posses the P1 and P antigens

• P₂ phenotype

• anti-P1

(P and Glob system) (——) lacks P₁ antigen, but expresses the P antigen; can make the antibody (——)

• p phenotype

• anti-P₁PP^k (anti-Tj^(a-))

(P and Glob system) (——) is the null phenotype. Lacks P₁, P, and P^k antigens. These people have the naturally occurring antibody (——)

• P₁^k phenotype

• anti-P

(P and Glob system) (——) phenotype RBCs express P₁ and P^k antigens. These people make naturally occurring (——)

• P₂^k phenotype

• anti-P₁ and anti-P

(P and Glob system) (——) phenotype RBCs express only p^k antigen. These people make the antibodies (—2—)

• P, P^k, P₁

• P and P^k

The most common phenotypes of the P system are P₁ and P₂. P₁ individuals have (—3—) antigens, while P₂ individuals have (—2—) antigens

• IgM

• RT (and in saline)

• Rarely a problem with transfusion

• Inhibited with P₁ substance (Hydatid cyst fluid)

Anti-P₁ characteristics (Ab class, rxn phase, clinical significance, special characteristics)

• P^k individual → hemolytic IgM (clinically significant)

• Paroxysmal cold hemoglobinuria → biphasic auto-IgG, “Donath Landsteiner”

Anti-P characteristics (P^k individual vs PCH)

IgG and IgM (very hemolytic, clinically significant)

Anti-PP₁P^k antibody class

anti-P1

Individuals infected with Echinococcus granulosus (and other parasitic infections) develop the antibody (——)

• anti-PP₁P^k

• anti-P

Early abortions are associated with the antibodies (—2—)

• E. coli

• Streptococcus suis

• Human parvovirus B19

Binding sites for (—3—) are associated with the terminal sugars for P1; toxins rom several pathogenic bacteria also have binding specificity for P1 terminal sugars

• branched (I) and linear (i) oligosaccharides

• glycosyltransferases

I and i are not antithetical alleles. They are (——) that are formed by the action of (——); they are expressed in a reciprocal relationship that is developmentally regulated (matures around 18 months)

• i antigen

• I antigen

(I/i group) Cordblood is (——) positive, but this status is temporary; as the neonate grows, the (——) becomes prevalent

anti-I

(I/i group) Most people have an auto (——) reacting at RT or 4°C

• IgM

• RT or below (prewarm eliminates activity)

• Clinically insignificant (no hemolysis, no HDFN, usually no HTR)

• Most people have it; react w/ most adult cells, negative w/ cordblood

Allo anti-I characteristics (Ab class, rxn temperature, clincial significance, prevalence)

• Mycoplasma pneumoniae infection

• Cold agglutinin disease

Auto anti-I is usually benign/nonpathogenic and can be secondary to (——), but it can be pathogenic when it is associated as the cause of (——)

• auto IgM

• WAIHA second to Hodgkin’s disease

Anti-I^T is an (——) antibody that reacts most strongly with cord cells, less strongly with I_adult cells, and most weak with i_adult. Responsible for (——-)

Anti-IH

(I system) primarily a harmless auto Ab in the serum to A1 and B individuals

Anti-IA₁ and Anti-IB

(I system) (—2—) react against oligosaccharides that express both the I antigen and the A or B antigen

Anti-IP₁

(I system) detects oligosaccharides that express the P₁ antigen and the I antigen

Anti-ILe^bH

(I system) detects a structure that expresses the I antigen, Le^b, and large quantities of H antigen

• Infectious mononucleosis (EBV)

• Lymphoproliferative disorders

Allo anti-i has not been described; auto anti-i is rare and is sometimes associated with (—2—)

Chromosome 4

Genes that encode for MNS antigens are located on (——)

Ns

In the MNS group, the most frequently inherited haplotype is…

• GYPA and GYPB

• GYPA

• GYPB

(MNSs) The genes (—2—) code for glycophorin A and B, respectively. (——) codes for M and N while (——) codes for S and s.

• Glycoproteins

• Sialic acid

• Sialoglycoproteins

(MNSs) Structures that carry MNSs antigens are (——); the majority of the sugars carry (——); the membrane structures are called (——-)

• 1 and 5

• 29

M and N only differ in their amino acid sequence at positions (—2—); S and s only differ in their amino acid sequence at position (——)

• IgM (rare IgG)

• RT (saline)

• Mostly clinically insignificant (no HDFN, no HTR)

• Enhanced by acidifying serum to pH=6.5

Anti-M characteristics (Ab class, rxn phase, clinical significance, enhancement)

• IgM

• weak at RT

• Mostly clinically insignificant

• temporary anti-N in dialysis pt because of formalin in tubing

Anti-N characteristics (Ab class, rxn phase, clinical significance, special characteristic)

Sulfhydral agents (reducing agents)

Kell glycoprotein antigens have a highly folded disulfide bonded region, so antigens are sensitive to treatment with (——) (2-ME, DTT, AET) wich reduce disulfide bonds

• K_x

• anti-K_u

K_o or K_null phenotype lacks al Kell antigens, but expresses another related group (——) in elevated levels. Sensitized individuals make (——)

K ag

The (——) is very immunogenic, 2nd to the D antigen

• IgG

• 37°C (reacts well at AHG)

• Clinically significant

• Donor must be Ag neg, AHG xmat compatible

anti-K and anti-k characteristics (class, rxn phase, clinical significance, transfusion)

Chromosome 1

Fy locus is located on (——)

Fy^x allele

(Duffy) while typing as Fy^b neg, it encodes for a weakened Fy^b antigen

Fy3

Genetic precursor to both Fy^a and Fy^b

Fy

This allele encodes no identifiable Duffy Ag

Fy(a-b-)

In this phenotype, RBCs resist malaria ivnasion from P. vivax and P. knowlesi merozoites

• IgG

• AHG

• Clinically significant

anti-Duffy characteristics (class, rxn phase, clincal significance)

Chromosome 18

Jk locus is found on…

• Jk^a and Jk3

• Jk^b and Jk3

The Jk^a allele encodes the (—2—) antigens and is codominant with Jk^b; Jk^b allele encodes the (—2—)

In(Jk)

Jk(a-b-) phenotype can also be derived by the action of a dominant suppressor gene (——) which is inherited separately. Individuals of this phenotype do no make anti-Jk3

• IgG

• AHG

• Clinically significant (bind C’, HDFN, HTR)

• Causes classic delayed HTR

Anti-Jk^a or anti-Jk^b characteristics (class, phase, clinical significance, special characteristic

• Jk(a-b-)

• Jk^a and Jk^b

Anti-Jk³ is found in some (——) individuals and reacts with (—2—); is considered a “pan Jk”

• IgG

• Clinically significant (HDFN, HTR)

• AHG IAT

• Donor units must be negative

S and s antibody characteristics (Ab class, significance, rxn phase, transfusion)

• Glycophorin B

• GYPB

• S and s

The U antigen is called the “universal” antigen because it is found in all individuals except 1% of African Americans. The U negative individual lacks (——) because of a partial or complete deletion of (——). Because of this, the U antigen is always present when (——) are inherited

• IgG

• Clinically significant

• AHG

• Anti-U^var pt can react with S neg s neg RBCs

U Ab characteristics (Ab class, clinical significance, rxn phase, special characteristics)

En^a

Partial or complete deletion of GPA. An antibody to this antigen is an umbrella term for Ab that reacts to various portions of GPA unrelated to M and N

M^k

Near complete deletion of GPA and GPB

Mi (Miltenberger) system

A subsystem of MNS system producing a number of low incidence Ags (currently 11)

M^g

With this phenotype, N will test as M-N+ leading to the false conclusion that genotype is NN; is of primary importance in paternity testing