Unit 4: Other Blood Groups

Question 1

How is Lewis blood group system unique?

Answer 1

Lewis blood group system gets adsorbed onto the RBC membrane from plasma

Question 2

Where are the lewis antigen located?

Answer 2

type 1 glycosphingolipids

Question 3

Why are Lea and Leb not antithetical?

Answer 3

they don’t result from alternative alleles of a single gene

Question 4

What is fucosyltransferase?

Answer 4

an enzyme that transfers a l-fuc sugar from GDP-fuc donor substrate to an acceptor

Question 5

What produces lewis antigens?

Answer 5

tissue cells (plasma/body secretions)

Question 6

Where is the Se gene located?

Answer 6

chromosome 19

Question 7

What are the two genes of Se?

Answer 7

Se and se (absence)

Question 8

Where does the Se gene add L-fuc?

Answer 8

to type 1 precursor chains (body fluids)

Question 9

What do you require to have Lewis B?

Answer 9

a Secretor

Question 10

In Le(a+b-) what genes are present? What is secreted?

Answer 10

Le and H genes, Le(a) antigen substance secreted

Question 11

In Le(a-b+) what genes are present? What is secreted?

Answer 11

Le, H and Se genes, A, B, H, Le(b) and small amts of Le(a)

Question 12

In Le(a-b-) what genes are present? What is secreted?

Answer 12

nothing, possibly have Se (must test)

Question 13

If you have a weak secretor gene what occurs?

Answer 13

you will have more Le(a) because it makes less Le(b) and causes Le(a+b+)

Question 14

Cord blood and RBCs of newborns type as Le___

Answer 14

Le(a-b-)

Question 15

In newborn secretions, if they have Le gene, what do they have?

Answer 15

Le(a) in secretions (saliva)

Question 16

At how many days old will Le be present on RBCs? What will show?

Answer 16

10 days, Le(a+b-)

Question 17

After 10 days… what will newborns type as

Answer 17

Le(a+b+)

Question 18

Why does Lw blood group substance transfusion rarely cause hemolysis of RBCs?

Answer 18

they bind to free-floating anti-Le(a or b) in plasma rather than ones attached to RBC membrane

Question 19

What does Anti-Le(bH) react with?

Answer 19

group O Le(b+) and A2 Le(b+)

Question 20

In the serum of Le(a-b-) secretors, what is found?

Answer 20

Anti-Le(a) and Anti-Le(b)

Question 21

What are techniques to ID anti-Le’s?

Answer 21

neutralization of antibodies

enzyme-treated cells that enhance reactivity

Question 22

Why don’t individuals who type Le(a-b+) make anti-Le(a)?

Answer 22

because they still have small amounts of Le(a)

Question 23

Lewis system is known to be associated with…

Answer 23

peptic ulcers
ischemic heart disease
cancer
kidney transplant rejection
helicobacter pylori

Question 24

Where are antigens M and N found?

Answer 24

glycophorin A

Question 25

Where are the S antigens found?

Answer 25

Glycophorin B

Question 26

What antibody is found frequently in human sera and agglutinates in saline?

Answer 26

Anti-M

Question 27

Anti-M exhibits the _______ with the N antigen

Answer 27

dosage effect

Question 28

Anti-M fails to react with....

Answer 28

enzyme-treated red cells (it gets destroyed)

Question 29

What are not common antibodies that are usually IgG and immune in nature?

Answer 29

Anti-S and Anti-s

Question 30

What antibody is rare and reacts with the cells of most people?

Answer 30

Anti-U

Question 31

What phenotype produces Anti-U? Which population is it almost exclusively found?

Answer 31

S-s-U- | African American

Question 32

En(a-) phenotype results from...

Answer 32

gene deletion at GYA locus for glycophorin A

Question 33

What is the M(k) phenotype?

Answer 33

single near-complete deletion of both GYPA and GYPB so they will have no M, N or S

Question 34

Which enzyme(s) destroys only S & s?

Answer 34

chymotrypsin

Question 35

Which enzyme(s) destroys only M & N?

Answer 35

trypsin ZZAP DTT w/ papain or ficin AET

Question 36

Which enzymes destroys all MNS?

Answer 36

ficin papain bromelin pronase

Question 37

Where are P & Globoside blood groups found?

Answer 37

RBCs, lymphocytes, granulocytes and monocytes

Question 38

What is the common precursor for globoside?

Answer 38

lactosylceramide

Question 39

What are the antigens for the P & Glb blood group system?

Answer 39

P P1 P(k) Luke (LKE)

Question 40

What antigen is assigned to the Glb system?

Answer 40

P antigen

Question 41

How long could it take for P1PK to be fully expressed?

Answer 41

7 years

Question 42

What could inhibit the P1 antigen expression?

Answer 42

In(lu) gene

Question 43

Where is the P1 antigen found?

Answer 43

in individuals with a hydatid cyst infection

Question 44

Where does the P1 gene reside? Where does the P antigen (GLOB) reside ?

Answer 44

chromosome 22 | chromosome 3

Question 45

What is known as the Donath-Landsteiner antibody?

Answer 45

(IgG) Anti-P

Question 46

Describe why Anti-P is a powerful biphasic hemolysin...

Answer 46

it attaches to red cells in the cold buy lyses them in warmer temps

Question 47

What are the diseases associated with the P1Pk and Glb blood group systems?

Answer 47

``` hydatid cyst infection fascioliasis adenocarcinoma HTRs HDNs PCH Tertiary syphilis acute condition secondary to viral infection shigella dysentery E. coli-associated hemolytic uremic syndrome UTIs ```

Question 48

What is the structure of i vs I?

Answer 48

i is linear and I is branched

Question 49

How are i and I antigens formed?

Answer 49

glycosyl transferases

Question 50

What is the principle of adsorption?

Answer 50

removes antibodies from serum by adding target antigen, it gets agglutinated and then removed by centrifugation

Question 51

What is human plt concentrates used for?

Answer 51

to adsorb Bg-like antibodies from serum

Question 52

What is RESt? What does it process?

Answer 52

ID's cold-reacting autoantibodies, it processes I, H and IH-like structures

Question 53

How are autoantibodies removed?

Answer 53

adsorption techniques

Question 54

If reactivity occurs during autoadsorption...

Answer 54

autoantibody remains in serum and further adsorption is necessary

Question 55

Describe homologous adsorption...

Answer 55

patient is phenotyped, then phenotypically matched RBCs are used for the adsorption in place of autologous cells.

Question 56

What blood group systems are treated with enzymes to be negative for DAT?

Answer 56

duffy and MNS

Question 57

What is the most critical step in preparing the eluate?

Answer 57

original washing

Question 58

What are the enzymes used to separate specificities and allows for ID?

Answer 58

trypsin ficin bromelin

Question 59

What do enzymes remove on the RBC surface?

Answer 59

Sialic Acid residues or glycoproteins

Question 60

Enzymes may be used in place of which enhancement medias?

Answer 60

LISS/PEG

Question 61

What is the purpose of pretransfusion testing?

Answer 61

to reveal any possible incompatibility between a donor's blood and the recipient's blood

Question 62

What is the second purpose of pretransfusion testing?

Answer 62

to select blood products with acceptable survival rates

Question 63

What is the major cause of transfusion-associated fatalities?

Answer 63

clerical errors

Question 64

What percentage of the errors are misidentification?

Answer 64

47%

Question 65

What is the preferred specimen for transfusion services?

Answer 65

plasma (no waiting time to clot)

Question 66

What is the preferred specimen for complement ID since EDTA could neutralize complement?

Answer 66

serum

Question 67

What is the major difference between a T/S vs a T/C?

Answer 67

in a T/C, the donor RBC is mixed with recipient RBC

Question 68

What occurs in a T/S and T/C if you have a positive antibody screen?

Answer 68

identify the antibody, perform AHG Xmatch then set aside antigen-negative blood for patient

Question 69

What is the most common bacterial contaminant?

Answer 69

Yersinia enterocolitica

Question 70

What are the phases of cross-matching?

Answer 70

Immediate spin crossmatch antiglobulin crossmatch Weak D (once)

Question 71

What test is sufficient for a patient receiving large volumes of plasma?

Answer 71

immediate spin crossmatch

Question 72

What are the massive transfusion measurements?

Answer 72

8-10 RBC units/24 hours or 4-5 RBC units/1 hour

Question 73

How can complete coagulation be accelerated?

Answer 73

adding thrombin

Question 74

What is the purpose of the MSBOS?

Answer 74

to promote more efficient utilization of blood and establish realistic blood ordering levels

Question 75

What is required for issuance of blood/blood components?

Answer 75

After all pretransfusion testing after all serological discrepancies resolved a minimum of 2 patient identifiers a written request