MIDTERM LECTURE L1: LUTHERAN BLOOD GROUP

Question 1

Lutheran blood group system ISBT

Answer 1

005

Question 2

Lutheran blood group system symbol

Answer 2

LU

Question 3

Anti-Lua was discovered in what year

Answer 3

1945

Question 4

Lu gene is located on what chromosome

Answer 4

chromosome 19

Question 5

The Lu gene is located on chromosome 19 at what specific position

Answer 5

19q13.2

Question 6

Anti-Lua was found after transfusion in the serum of a patient with what disease

Answer 6

lupus erythematosus

Question 7

The newly discovered antibody was named as ‘Lutheran’, which came from the

Answer 7

donor’s last name ‘Lutteran’

Question 8

Why is it called Lutheran and not Lutteran

Answer 8

the donor’s blood sample was incorrectly labeled

Question 9

This antibody was defined as the antithetical partner to Lua

Answer 9

anti-Lub

Question 10

They first described the anti-Lub

Answer 10

Cutbush and Chanarin

Question 11

In what year did Cutbush and Chanarin described anti-Lub

Answer 11

1956

Question 12

They described the null phenotype Lu(a-b-)

Answer 12

Crawford and colleagues

Question 13

The null phenotype Lu(a-b-) was identified as a recessive silent allele in what year

Answer 13

1963

Question 14

T/F: The null phenotype Lu(a-b-) only demonstrated recessive inheritance

Answer 14

F (It was first discovered demonstrating dominant inheritance)

Question 15

How many antigens are part of the Lutheran system

Answer 15

twenty (20)

Question 16

Obsolete antigens of the Lutheran system

Answer 16

Lu10 and Lu15

Question 17

How many sets of Lutheran antigens are antithetical

Answer 17

4 sets

Question 18

T/F: Lutheran antigens have either high prevalence or very low prevalence

Answer 18

T

Question 19

Why blood bankers seldom deal with the serology of Lutheran blood group system?

Answer 19

Lutheran antigens have either high prevalence (thus only few people make an alloantibody)

or very low prevalence (thus, only few people are ever exposed)

Question 20

Lutheran antigens are poorly developed at birth, but can be detected on fetal RBCs as early as how many weeks of gestation?

Answer 20

10-12 weeks

Question 21

Lutheran glycoprotein is widely distributed in what tissues/organs? enumerate

Answer 21

• brain
• lung
• pancreas
• placenta
• skeletal muscles
• hepatocytes (especially fetal hepatic epithelial cells)

Question 22

Why does the presence of Lutheran glycoprotein on placental tissue decreases the likelihood of HDFN?

Answer 22

Its presence may result in adsorption of maternal antibodies to Lutheran antigens

Question 23

Lutheran antigens are resistant to?

Answer 23

• enzymes: ficin and papain
• glycine-acid EDTA

Question 24

Lutheran antigens are destroyed by?

Answer 24

enzymes: trypsin & α-chymotrypsin

Question 25

Most Lutheran antibodies do not react with RBCs treated with what reagents?

Answer 25

sulfhydryl reagents: - Dithiothreitol (DTT) - 2-Aminoethanethiol (AET)

Question 26

T/F: Lua and Lub antigens are produced by allelic dominant-recessive genes

Answer 26

F (they're produced by allelic codominant genes)

Question 27

In Lua and Lub antigens, most individuals express which Lutheran antigen?

Answer 27

Lu(b+)

Question 28

How many percent of whites express Lu(a+)

Answer 28

8%

Question 29

How many percent of blacks express Lu(a+)

Answer 29

5%

Question 30

Number of Lub sites on Lu(a–b+) per RBC is estimated to be

Answer 30

1,640 to 4,070

Question 31

Number of Lub sites on Lu(a+b+) per RBC is estimated to be

Answer 31

850 to 1,820

Question 32

Most of the anti-Lua is what immunoglobulin class?

Answer 32

IgM

Question 33

At what temperature do anti-Lua antibodies typically react better?

Answer 33

room temperature

Question 34

Some anti-Lua react at 37C via what test

Answer 34

indirect antihuman globulin test (IAT)

Question 35

Why anti-Lua often goes undetected in routine testing?

Answer 35

Because most reagent RBCs are Lu(a–)

Question 36

What visual clue in a test tube helps experienced technologists to recognize Lutheran antibodies like anti-Lua?

Answer 36

loose mixed-field agglutination/reactivity pattern

Question 37

Anti-Lua that react only at temperatures <37°C are clinically insignificant/significant(?)

Answer 37

Clinically insignificant

Question 38

Anti Lua reacts well with what solution

Answer 38

saline

Question 39

thermal optimum of anti-Lua

Answer 39

12-23C

Question 40

T/F: In anti-Lua there are no documented cases of immediate HTRs.

Answer 40

T

Question 41

In anti-Lua, what type of HTRs are only documented?

Answer 41

rare and mild delayed HTRs

Question 42

This Lutheran antibody has been implicated with shortened survival of transfused cells and post-transfusion jaundice

Answer 42

anti-Lub

Question 43

Most of anti-Lub are what class of immunoglobulin

Answer 43

IgG

Question 44

Aside from IgG, what other immunoglobulin classes have been noted in anti-Lub

Answer 44

IgM and IgA

Question 45

Anti-Lub is incomplete/complete(?) antibody

Answer 45

incomplete antibody

Question 46

Anti-Lub reacts better at what phase

Answer 46

AHG phase

Question 47

Lutheran amorphic gene

Answer 47

Lu(a-b-)

Question 48

Lutheran inhibitor gene

Answer 48

InLu, dominant type

Question 49

T/F: Anti-Lub has been reported to cause severe or acute hemolysis

Answer 49

F (has not been reported)

Question 50

The Lutheran antigens are located on what protein?

Answer 50

type 1 transmembrane protein

Question 51

2 forms of a type 1 transmembrane protein exist due to

Answer 51

of alternative RNA splicing

Question 52

2 forms of a type 1 transmembrane protein

Answer 52

- longer Lu glycoprotein - shorter basal cell adhesion molecule (B-CAM)

Question 53

The longer 85-kD protein contains how many amino acids?

Answer 53

597 amino acids

Question 54

The longer 85-kD protein contains how many extracellular domains?

Answer 54

5 extracellular domains

Question 55

The longer 85-kD protein contains hydrophobic transmembrane domain of how many amino acids?

Answer 55

19 amino acids

Question 56

The longer 85-kD protein contains cytoplasmic domain of how many amino acids?

Answer 56

59 amino acids

Question 57

The Lutheran proteins are multifunctional adhesion molecules that bind?

Answer 57

laminin

Question 58

The Lutheran proteins bind laminin which is notable in what disease

Answer 58

sickle cell disease

Question 59

The expression of Lutheran was thought to be suppressed by what rare dominant regulator gene

Answer 59

In(Lu)

Question 60

In(Lu) stands for

Answer 60

“inhibitor of Lutheran"

Question 61

Mutations in the gene for what transcription factor, shows association with the In(Lu) phenotype?

Answer 61

gene for Erythroid Krüppel-like Factor (EKLF) (a transcription factor)

Question 62

Difference of dominant type Lu(a-b-) and Recessive type (a-b-)

Answer 62

Dominant type Lu(a–b–) RBCs carry trace amounts of Lutheran antigens Recessive Lu(a–b–) RBCs truly lack all Lutheran antigens (i.e., they have the null phenotype)

Question 63

Dominant/Recessive(?) type Lu(a-b-) can make inseparable anti-Luab

Answer 63

Recessive type Lu(a-b-)

Question 64

The inseparable anti-Luab is called

Answer 64

anti-Lu3

Question 65

This pattern of inheritance has an X-borne inhibitor to Lutheran.

Answer 65

Recessive X-Linked Inhibitor Type

Question 66

A rare antibody that reacts with all RBCs except Lu(a–b–) RBCs

Answer 66

Anti-Lu3

Question 67

T/F: Anti-Lu3 is usually antiglobulin-reactive

Answer 67

T

Question 68

Dominant type Lu(a–b–) RBCs also can have reduced/weak expression of? enumerate

Answer 68

- CD44 - P1 - i - AnWj - MER2, - Inb

Question 69

This type of Lu(a-b-) phenotype is the result of having two rare silent alleles LuLu at the Lutheran locus

Answer 69

Recessive Type Lu(a–b–)