MNSs

Question 1

ISBT — discovered by — in 1927 when —

Answer 1

ISBT 002

Discovered by Landsteiner and Levine in 1927 when immunizing rabbits

Question 2

composed of how many antigens?
enumerate the most common

Answer 2

MORE THAN 40 ANTIGENS
most common: M, N, S, s, U

Question 3

T or F: MNSs found on RBCs and some secretions but NOT in tissues

Answer 3

FALSE
found on RBCs and some tissues but NOT in secretions

Question 4

lectins used for MN typing

anti-M: ?
anti-N: ?

Answer 4

anti-M: Iberis amara
anti-N: Bauhinia variegata and Bauhinia purpura

Question 5

MNSs genetics

genes are traced at?

Answer 5

chromosome 4q28-q31

Question 6

MNSs genetics

GYPA gene codes for?
GYPB gene codes for?

Answer 6

GYPA codes for glycophorin A
GYPB codes for glycophorin B

Question 7

MNSs genetics

GYPA gene considered to be the — with how many exons?

Answer 7

considered to be the ancestral gene with 7 exons

Question 8

MNSs genetics

how many exons in GYPB gene?

Answer 8

5 exons and one noncoding (pseudoexon)

Question 9

MNSs genetics

alleles for GYPA and GYPB are codominant. both are —

Answer 9

highly homologous

Question 10

MNSs antigens are —

Answer 10

fully developed at birth

Question 11

MNS5 is — antigen
MNS1 is — antigen
MNS2 is — antigen
S antigen is —
s antigen is —

M and N antigen both resides in the — of the —

Answer 11

MNS5: U antigen
MNS1: M antigen
MNS2: N antigen
MNS3: S antigen
MNS4: s antigen

M and N antigen both resides in the glycophorin A of the RBC membrane

Question 12

MNSs antigens are attached to the glycophorin proteins and these proteins are — and therefore called —

Answer 12

Sialic-acid rich glycoproteins and are called sialoglycoproteins

Question 13

M and N antigens are at the — of GPA.

GPA and GPB are also expressed in —

Answer 13

at the EXTREME TERMINUS of GPA.

expressed in renal endothelium and epithelium

Question 14

M antigen is defined by?

there are — copies of GPA per RBC.

Answer 14

Leucine and Glutamic acid

200,000 - 1,000,000 copies of GPA per RBC

Question 15

N antigen is defined by?

Answer 15

Serine and Glycine

Question 16

S and s antigens are discovered by? in what year?

Answer 16

Walsh and Carmel Montgomery
1947

Question 17

the s antigen was discovered in what year?

what is the antithetical partner of S?

Answer 17

1951

s antigen

Question 18

S and s antigens are found in?

Answer 18

Glycophorin B on RBC membrane

Question 19

S antigen is defined by?
s antigen is defined by?

there are — copies of GPB per RBC.

Answer 19

S antigen: methionine
s antigen: threonine

there are 50,000 - 250,000 copies of GPB per RBC.

Question 20

T or F: U antigen is found in glycophorin C on RBC membrane.

Answer 20

FALSE
Glycophorin B

Question 21

this antigen is considered as the universal antigen. and why it is considered as universal?

Answer 21

U antigen
bcos this was known to be the high incidence antigen

Question 22

T or F: U antigen is found on RBCs of all individuals except about 5% of Americans.

Answer 22

FALSE.
except about 1% of African Americans (1-35% Africans)

Question 23

T or F: RBCs with U antigen also carries S and s antigens. then why?

Answer 23

TRUE.
because they both found in glycophorin B on RBC membrane.

Question 24

U antigen is discovered by? via — in what year?

Answer 24

Weiner via anti-U in 1953

Question 25

M and N are easily destroyed by what enzymes?

Answer 25

- Ficin - Papain - Bromelin - Trypsin - Pronase

Question 26

T or F: S and s resistant to enzymes. | if not, what are the enzymes that could possibly destroy?

Answer 26

FALSE. they are not resistant but **less easily destroyed** | **Ficin, Papain, Bromelin, Pronase, Chymotrypsin**

Question 27

enzymes can destroy S and s activity but the *amount of degradation* depend on the?

Answer 27

- strength of the enzyme solution - length of treatment - enzyme to cell ratio

Question 28

these enzymes cannot destroy S and s. enumerate!

Answer 28

- trypsin - dithiothreitol - glycine-acid EDTA

Question 29

what is antithetical?

Answer 29

antithetical is used to describe a pair or more than a pair of antigens that are **coded by different alleles of a single gene**

Question 30

# frequencies in **white and blacks** M+

Answer 30

W: **78%** B: **74%**

Question 31

# frequencies in **white and blacks** N+

Answer 31

W: 72% B: 75%

Question 32

# frequencies in **white and blacks** S+

Answer 32

W: 55% B: 31%

Question 33

# frequencies in **white and blacks** s+

Answer 33

W: 89% B: 93%

Question 34

# frequencies in **white and blacks** U+

Answer 34

W: 99.90% B: 99%

Question 35

anti-M and anti-N are ---, rarely natural bcos?

Answer 35

**IgM** bcos they are formed due to **transfusion or pregnancy**

Question 36

T or F: anti-M and anti-N do not bind complement and causes HDNs and HTRs

Answer 36

FALSE **does not causes** HDN and HTRs

Question 37

what are the similarities of anti-M and anti-N?

Answer 37

they are both: - cold reactive agglutinins - reaction is enhanced by **acidification** - reacts best at **4C**

Question 38

this antibody can demonstrate dosage. the reaction is enhanced at what pH?

Answer 38

**anti-M** pH: 6.5

Question 39

anti-M is observed from? common in?

Answer 39

observed from MULTIPAROUS WOMEN common in **children** and in **patients with bacterial infection**

Question 40

# identify what antibody. some are IgG, less common, and specific at --- pH

Answer 40

**anti-N** specific at ALKALINE pH

Question 41

anti-N can demonstrate dosage (reacts better with --- than ---) | this is observed in?

Answer 41

reacts better with **M-N+** than **M+N+** | **renal patients** where dialysis machine is sterilized with FORMALIN

Question 42

anti-S and anti-s, both are --- and in --- | may exhibit?

Answer 42

both are IgG and in AHG phase | may exhibit **dosage effect**

Question 43

anti-S and anti-s reacts at --- but some reacts at ---

Answer 43

37C but some reacts at **10-22C**

Question 44

if anti-S or anti-s specificity is suspected but the pattern of reactivity is unclear, what will u do?

Answer 44

incubate test at room temp and perform AHG immediately

Question 45

T or F: anti-S and anti-s does not bind complement and does not cause HDFN and HTR.

Answer 45

FALSE. - binds complement - can cause **HDFN** and **HTR with hemoglobinuria**

Question 46

anti-U is an --- and is enhanced with enzyme treatment. reacts at? | anti-U causes?

Answer 46

IgG reacts at **37C** and **AHG phase** | **HDFN, HTR, decreased Red cell survival**

Question 47

# true or false some individuals have altered GPA and their antibody is not specific for a portion of the antigen they lack. | this is also referred as?

Answer 47

FALSE. their antibody is **SPECIFIC** | reffered as **MNSs autoantibodies**