Uncommon Blood Group Flashcards
(107 cards)
1
Q
play a major role in ore-transfusion testing outcomes
A
ABO and Rh
2
Q
More than ____ unique antigens belonging to additional blood group systems exist out there have been identified
A
300 unique antigens
3
Q
Antigenic exposure usually occurs in
A
Pregnancy or Blood Transfusions
4
Q
8 Major Blood Group System
A
Kell, Duffy, Lutheran, Lewis, I, P, MNSs, Kidd
5
Q
11 Minor Blood Group Systems
A
XG, Scianna, Dombrock, Cartwright, Chido-Rodgers, Colton, Knops, Indian, Gerbich, BG, Diego
6
Q
When and who discovered MNSs Blood Group
A
Discovered by Landsteiner and Levine in 1927 when immunizing rabbits
7
Q
MNSs Blood Group ISBT #
A
002
8
Q
MNSs Blood Group is Composed of more than ____ antigens, with the most common: ___
A
40 antigens, most common: M, N, S, s, and U
9
Q
Lectins used for MN typing:
A
Anti-M- Iberis amara
Anti-N- Vicia graminea, Bauhinia variegata, Bauhinia purpura
10
Q
MNSs genes are traced at?
A
chromosome 4q28-q31
11
Q
what gene codes for glycophorin A
A
GYPA gene
12
Q
what gene codes for Glycophorin B
A
GYPB gene
13
Q
Considered to be the ancestral gene
A
GYPA gene
14
Q
how many exons does the gypa ang gypb genes have
A
gypa - 7 exons
gypb - 5 exons and one noncoding (pseudoexon)
15
Q
similarities between gypa and gypbd
A
- Alleles for GYPA and GYPB are codominant
- Both are highly homologous
16
Q
antigens that are fully developed at birth
A
MNSs Antigens
17
Q
M (MNS1) & N(MNS2) antigens reside in the
A
in the Glycophorin A of the RBC membrane
18
Q
Biochemically, MNSs antigens are attached to the glycophorin proteins - These proteins are
A
Sialic acid-rich glycoproteins, therefore called “Sialoglycoproteins”
19
Q
M and N are at the ____ of GPA
A
extreme terminus
20
Q
GPA and GPB are also expressed in??
A
renal endothelium and epithelium
21
Q
N antigen is defined by __ and ___
A
Leucine and Glutamic acid
22
Q
M antigen is defined by
A
defined bv Serine and Glycine
23
Q
how many copies of GPA is there per RBC
A
200, 000 to 1, 000, 000 copies
24
Q
S (MNS3), s (MNS4) antigens is discovered in __ by __
A
Discovered in 1947 by Walsh and Carmel Montgomery
25
The s antigen (antithetical partner of S) was discovered in?
1951
26
S (MNS3), s (MNS4) antigens can be found in ___ on RBC membrane
Glycophorin B
27
S antigen is defined by ___
methionine
28
s antigen is defined by
threonine
29
how many copies of GPB is there per RBC
50, 000 to 250, 000 copies
30
U (MNS5) antigens can be found in ___ on RBC membrane
Glycophorin B
31
is a "Universal" antigen. This makes it a **high incidence** antigen
U (MNS5) antigens
32
where can u antigens be found among individuals
Found on RBCs of all individuals except about 1% of African Americans (1-35% Africans)
33
U (MNS5) antigens was discovered by ___ via ___ in ___
Weiner via anti-U in 1953
34
RBCs with U antigen also carries what antigen?
S and s antigens
35
is one or more antigens produced by alleles at a single gene locus or at loci so closely linked that
crossing over does not occur or is very rare
blood group system
36
where can MNSs Blood Group (ISBT # 002) be found
Found on RBCs and some fissues but NOT in secretions
37
MNSs Blood Group (ISBT # 002) is used for what test?
paternity testing
38
39
M and N are easily destroyed by what enzymes
(Ficin, Papain, Bromelin, Trypsin, and Pronasel
40
are less easily destroyed by enzymes
S and s
41
42
Ficin, Papain, Bromelin, Pronase and Chymotrypsin can destroy s and s activity but the amount of degradation may depend on the?
strength of the enzyme solution, length of treatment, and enzyme-to-cell ratio
43
enzymes that cannot destroy S and s
Trypsin, Dithiothreitol, Glycine-acid EDTA
44
a term used to describe a pair (and occasionally more than a pair) of antigens that are coded by different alleles of a single gene
Antithetical
45
M antigen frequency in whites and blacks
whites - 78%
blacks - 74%
46
N+ antigen frequencies in whites and blacks
whites 72%
blacks 75%
47
S+ antigen frequencies in whites and blacks
whites - 55%
blacks - 31%
48
s+ antigen frequencies in whites and blacks
whites - 89%
black - 93%
49
U+ antigen frequencies in whites and blacks
whites: 99.90%
blacks: 99%
50
rarely natural (formed due to transfusion or pregnancy)
IgM
51
What are the characteristics of Anti-M and Anti-N antibodies?
• IgM (rarely natural, can form due to transfusion or pregnancy)
• Cold-reactive saline agglutinins (best at 4°C)
• Do not bind complement (do not cause HDFN or HTR)
• Reaction enhanced by acidification
52
What are the unique features of Anti-M?
• Reaction enhanced at pH 6.5
• Common in multiparous women
• Observed in children and bacterial infections
• Can demonstrate dosage
53
What are the unique features of Anti-N?
• Less common than Anti-M
• Specific at alkaline pH
• Some are IgG
• Can demonstrate dosage (reacts better with M−N+ than M+N+)
• Observed in renal patients using formalin-sterilized dialysis machines
54
What are the characteristics of Anti-S and Anti-s?
• IgG, reactive in AHG phase
• Reacts at 37°C (some between 10°C–22°C)
• Binds complement, can cause HDFN and HTR with hemoglobinuria
• May exhibit dosage effect
55
What are the characteristics of Anti-U?
• IgG, enhanced with enzyme treatment
• Reacts at 37°C and AHG phase
• Can cause HDFN and HTR
• Associated with decreased red cell survival
56
How do MNSs autoantibodies develop?
• Some individuals have altered glycophorin A (GPA)
• Their antibodies target the missing portion of the common antigen
57
How was the Lutheran (Lu) blood group discovered
Discovered in 1945 in a Lupus erythematosus patient
58
Anti-Lua was named after the donor ___
“Lutheran” (originally “Lutteran” but mislabeled)
59
was discovered in __ as the antithetical partner to Lua
Anti-Lub 1956
60
anti M is commonly seen in?
multiparous women, children and bacterial infections
61
62
ISBT #005
LUTHERAN BLOOD GROUP - "Lu"
63
64
How many antigens are in the Lutheran system?
20 antigens
65
When are Lutheran antigens detected on fetal RBCs?
As early as 10-12 weeks of gestation
66
How well developed are Lutheran antigens at birth?
Poorly developed
67
On which tissues, besides RBCs, are Lutheran antigens found?
Brain, lungs, pancreas, placenta, skeletal muscle, and hepatocytes
68
Which enzymes destroy Lutheran antigens?
Trypsin and alpha-chymotrypsin
69
Which enzymes do NOT destroy Lutheran antigens?
Ficin, papain, glycine-acid EDTA
70
What type of protein are Lutheran antigens located on?
Type 1 transmembrane protein
71
How many forms of Lutheran glycoproteins exist?
Two (due to alternative RNA splicing)
72
Describe the Longer Lu glycoprotein.
• 85 kD protein
• 597 amino acids
• 19 amino acid hydrophobic transmembrane domain
• Cytoplasmic domain with 59 amino acids
73
Describe the Shorter basal cell adhesion molecule.
• 78 kD protein
• Shorter cytoplasmic domain
• External portion has five disulfide-bonded domains
74
To which superfamily do Lutheran glycoproteins belong?
Immunoglobulin superfamily
75
What is the function of Lutheran antigens?
Linked to adhesion properties and intracellular signaling
76
What is the significance of Lutheran antigen presence in the placenta?
Contributes to decreased likelihood of HDFN via adsorption
77
On which chromosome is the Lu gene located?
Chromosome 19q13.2
78
Which other blood group gene is linked to the Lu gene?
Secretor (Se) gene
79
What immunoglobulin class is Anti-Lua?
IgM
80
How does Anti-Lua react?
• Naturally occurring saline agglutinin
• Reacts at room temperature
• Some can bind complement
81
Can Anti-Lua cause hemolytic transfusion reactions (HTRs)?
Yes, but usually delayed HTRs
82
What immunoglobulin class is Anti-Lub?
Usually IgG
83
How does Anti-Lub react?
Reacts at 37°C and AHG phase
84
Can Anti-Lub cause hemolytic disease of the fetus and newborn (HDFN)?
Rare, but possible
85
anti lub is stimulated by?
pregnancy or transfusion
86
What type of immunoglobulin is Anti-Lu3?
IgG
87
What makes Anti-Lu3 unique?
It reacts with all RBCs except Lu(a-b-) RBCs
88
What type of immunoglobulin is Anti-Lua?
IgM
89
How does Anti-Lua react?
• Naturally occurring saline agglutinin
• Reacts at room temperature
• Can cause delayed hemolytic transfusion reactions (HTRs)
90
What type of immunoglobulin is Anti-Lub?
IgG
91
How does Anti-Lub react?
• Reacts at 37°C & AHG phase
• Stimulated by pregnancy or transfusion
• Can cause delayed HTRs
92
When and how was the XG blood group discovered?
In 1962, from the serum of a multiply transfused man
93
What was the first XG antigen discovered?
Xga
94
Why does Xga antigen have a higher prevalence in females?
It is controlled by an X-linked gene
95
How did the XG blood group get its name?
• “X” for the X chromosome
• “G” for Grand Rapids, where the patient was treated
96
Where is the XG gene located?
Xp22.3 on the X chromosome
97
Which gene codes for CD99?
MIC2, located at Xp22.2
98
Why was CD99 included in the XG system?
MIC2 and XG genes are adjacent and homologous
99
How does the Xga glycoprotein interact with the RBC membrane?
It crosses the RBC membrane once
100
What is the prevalence of Xga in men vs. women?
• 66% in men
• 89% in women
101
Why do women have a higher prevalence of Xga?
Women have two X chromosomes, so they can be homozygous or heterozygous
102
Why was CD99 added to the XG system?
It is genetically adjacent to the XG gene and shares homology
103
What immunoglobulin type are XG antibodies?
IgG
104
Are XG antibodies naturally occurring?
Yes
105
Do XG antibodies cause HDFN or HTRs?
No
106
107
Lua and Lub are produced by
allelic codominant genes
