OTHER BLOOD GROUP SYSTEMS PART 3 (LU)

Question 1

• (?) were first recognized in 1945 when (?) was discovered in a patient with lupus erythematosus diffusus after receiving a transfusion with blood carrying the low-incidence antigen.

Answer 1

Lutheran antigens

anti-Lua

Question 2

was misinterpreted as Lutheran, derived from the donor’s name Luteran

Answer 2

• Anti-Lua

Question 3

Subsequently, [?], the antithetical partner to Lua, was described in 1956.

Answer 3

anti-Lub

Question 4

was described in 1961, demonstrating dominant inheritance, contrary to most null phenotypes at the time.

Answer 4

Lu(a-b-)

Question 5

inherited as a recessive silent allele was identified.

Answer 5

Lu(a-b-)

Question 6

were used to test antibodies to unknown high-incidence antigens.

Answer 6

Rare Lu(a-b-) RBCs

Question 7

Some sera showed a phenotypic relationship to Lutheran, reacting with all RBCs except

Answer 7

Lu(a-b-)

Question 8

These specificities were given numeric designations (?) to represent their association with the Lutheran system.

Answer 8

Lu4, Lu5, Lub, etc.

Question 9

Three pairs of antithetical antigens (?) have been shown to be inherited at the Lutheran locus.

Answer 9

Lu6 and Lu9, Lu8 and Lu14, Lu18 and Lu19

Question 10

Several antigens have been shown to be located on the Lutheran glycoprotein, while three antigens (?), often referred to as para-Lutheran, have limited evidence of belonging to the Lutheran system.

Answer 10

Lu11, Lu16, Lu17

Question 11

• The ISBT designation of the Lutheran blood group system is

Answer 11

LU or 005.

Question 12

• Allelic Codominant Genes: are, produced by allelic codominant genes.

Answer 12

Lua and Lub antigens

Question 13

• Common Phenotypes: Most individuals express[?], while [?] phenotype is less common.

Answer 13

Lu(b)

Lu(a)

Question 14

• Variable Expression: expression varies between individuals and even within an individual’s RBCs.

Answer 14

Lutheran antigen

Question 15

strength has been confirmed to have low density
and variable expression.

Answer 15

Lub antigen

Question 16

• Development: Antigens have been detected on fetal RBCs as early as [?], but they are poorly developed at birth and reach adult levels by age 15 years.

Answer 16

10 to 12 weeks of gestation

Question 17

• Distribution: have not been found on platelets, lymphocytes, monocytes, or granulocytes.

Answer 17

Lutheran antigens

Question 18

is widely distributed in tissues such as the brain, lung, pancreas, placenta, skeletal muscle, and hepatocytes, especially fetal hepatic epithelial cells.

Answer 18

Lutheran glycoprotein

Question 19

Type: Most examples are IgM naturally_ occurring saline agglutinins. Some may also be IgA or IgG.

Answer 19

•Anti-Lua

Question 20

Reactivity: They typically react better at room temperature than at 37°C, although some may react at 37°C by indirect antiglobulin test

Answer 20

Anti-Lua

Question 21

are capable of binding complement, but in-vitro hemolysis has not been reported.

Answer 21

Anti-Lua

Question 22

• Detection: often goes undetected in routine testing because most reagent cells are Lu(a).

Answer 22

Anti-Lua

Question 23

It is more likely encountered as an incompatible crossmatch or during an antibody workup for another, specificity.

Answer 23

Anti-Lua

Question 24

Experienced technologists recognize Lutheran antibodies by their characteristic loose, mixed-field reactivity in a test tube.

Answer 24

Anti-Lua

Question 25

Effect of Enzymes: is not profoundly altered with common blood bank enzymes such as ficin and papain, but it can be destroyed with trypsin, chymotrypsin, pronase, AET, and DTT.

Answer 25

Anti-Lua

Question 26

Most are clinically insignificant in transfusion.

Answer 26

Anti-Lua

Question 27

There is one report of normal or near-normal survival of Lu(a) RBCs in a patient with

Answer 27

Anti-Lua

Question 28

Immediate transfusion reactions due to are undocumented, and delayed reactions are rare and mild.

Answer 28

Anti-Lua

Question 29

Hemolytic Disease of the Newborn (HDN): Because Lutheran antigens are poorly expressed on cord RBCs, cases of HDN associated with [?] are mild.

Answer 29

Anti-Lua

Question 30

Infants may exhibit weakly positive or negative direct antiglobulin tests and mild to moderate elevations in bilirubin.

Answer 30

Anti-Lua

Question 31

Many require no treatment, while others respond to simple phototherapy.

Answer 31

Anti-Lua

Question 32

In one report of mild HDN, the mother's antibody titer rose to 4096.

Answer 32

Anti-Lua

Question 33

Although the first example of [?] was a room-temperature agglutinin, most [?] is gG and reactive at 37°C at the antiglobulin phase.

Answer 33

Anti-Lub

Question 34

IgM and IgA antibodies have also been noted.

Answer 34

Anti-Lub

Question 35

It is primarily made in response to pregnancy or transfusion.

Answer 35

Anti-Lub

Question 36

reacts with all cells tested except the auto-control, and reactions are often weaker with Lu(a-b-) RBCs and cord RBCs.

Answer 36

Alloanti-Lub

Question 37

Ficin or papain does not significantly alter reactivity.

Answer 37

Anti-Lub

Question 38

AET or DTT should destroy Lub antgen through disruption of the disulfide bond of the glycoprotein, but this may require optimal conditions.

Answer 38

Anti-Lub

Question 39

Autologous RBCs will test [?] if typing sera are available.

Answer 39

Lu(a)

Question 40

has been implicated with shortened survival of transfused cells and post-transfusion jaundice, but severe or acute hemolysis has not been reported

Answer 40

Anti-Lub

Question 41

Chromium survival studies demonstrate a rapid initial clearance of some Lu(b-) RBCs but much slower removal of those remaining

Answer 41

Anti-Lub

Question 42

may be regarded as clinically significant, but blood should not be withheld in emergency situations just because compatible units cannot be found

Answer 42

Anti-Lub

Question 43

is associated with only mild cases of HDN.

Answer 43

anti-Lua, anti-Lub

Question 44

This type of Lu(a-b-) phenotype is the result of a rare dominant regulator gene, which suppresses the expression of Lutheran antigens.

Answer 44

• Dominant In(Lu) Type

Question 45

Blood donor screenings have shown the frequency of this type of Lutheran null to be relatively rare.

Answer 45

• Dominant In(Lu) Type

Question 46

Individuals with this phenotype do not make anti-Lu3.

Answer 46

• Dominant In(Lu) Type

Question 47

In some families, the Lu(a-b-) phenotype demonstrates recessive inheritance, resulting from having two rare silent alleles at the Lutheran locus.

Answer 47

• Recessive Lulu Type

Question 48

Individuals with this phenotype truly lack all Lutheran antigens and can make an inseparable anti-Luab called anti-Lu3.

Answer 48

• Recessive Lulu Type

Question 49

This rare Lu(a-b-) phenotype, observed in a large Australian family, is thought to be the result of an X-borne inhibitor to Lutheran.

Answer 49

• Recessive X-Linked Inhibitor Type

Question 50

All Lu(a-b-) family members were male and carried trace amounts of Lub detected by adsorption-elution.

Answer 50

• Recessive X-Linked Inhibitor Type

Question 51

Lu(a-b-w) individuals with weakened Lutheran antigens, also known as Lu(w), may result from In(Lu) with a lesser degree of penetrance or an allele to In(Lu) that causes less suppression.

Answer 51

• Lu(w) Phenotype

Question 52

is a rare antibody that reacts with all RBCs except those testing Lu(a-b-).

Answer 52

Anti-Lu3

Question 53

It is usually antiglobulin-reactive.

Answer 53

Anti-Lu3

Question 54

This antibody is made only by Lulu individuals, i.e., the recessive type of Lu(a-b-).

Answer 54

Anti-Lu3

Question 55

It is associated with only mild cases of HDN.

Answer 55

Anti-Lu3

Question 56

RBCs from dominant and X-linked type Lu(a-b-) individuals can be safely transfused to patients with anti-Lu3.

Answer 56

Anti-Lu3

Question 57

Other Lutheran Antigens:

Answer 57

• Lu4, Lu5, Lu7, Lu12, Lu13, and Lu20 • Lu11. Lu16, and Lu17

Question 58

are antigens of very high incidence that are absent from Lu(a-b-) RBCs.

Answer 58

• Lu4, Lu5, Lu7, Lu12, Lu13, and Lu20

Question 59

They are located on the Lutheran glycoprotein and have not been shown to be inherited at the Lu locus.

Answer 59

• Lu4, Lu5, Lu7, Lu12, Lu13, and Lu20

Question 60

are high-incidence antigens phenotypically related to Lutheran but have not been shown to be located on the Lutheran glydoprotein nor have they been shown to be inherited.

Answer 60

• Lu11, Lu16, and Lu17

Question 61

The Lutheran (Lu) system comprises two major antigens, [?], giving rise to four possible phenotypes: Lu(a+b-), Lu(a+b+), Lu(a-b+), and Lu(a-b-).

Answer 61

Lua and Lub

Question 62

Among these, [?] is the most common phenotype.

Answer 62

Lu(a-b+)

Question 63

• The genes encoding for the Lu antigens are linked to the

Answer 63

Se (secretor) genes

Question 64

• Both antibodies are rare.

Answer 64

anti-Lua, and anti-Lub

Question 65

react best at 37°C and often give a mixed field agglutination reaction

Answer 65

Lua

Question 66

react best at 37°C in the antiglobulin phase of testing.

Answer 66

Lub

Question 67

can cause mild hemolytic transfusion reactions (HTR), but they only rarely cause mild hemoiytic disease of the newborn (HDN)

Answer 67

• Lu antibodies

Question 68

[?] are often naturally occurring, while [?] typically develop after RBC stimulation by transfusion or pregnancy.

Answer 68

Lua antibodies Lub antibodies

Question 69

may manifest as a naturally occurring saline agglutinin that reacts optimally at room temperature.

Answer 69

• Anti-Lub

Question 70

is typically an IgG antibody reactive at the antiglobulin phase

Answer 70

• Anti-Lub

Question 71

usually produced in response to foreign RBC exposure during pregnancy or transfusion.

Answer 71

• Anti-Lub

Question 72

is rare and may result from three different genetic backgrounds, including dominant In(Lu) type, recessive Lulu type, and recessive X-linked inhibitor type

Answer 72

Lu(a-b-)