1What is the first to be identified in BB?
ABO blood group
2How is ABO unique?
only blood group that has naturally occurring Abs; does not require presence of foreign RBC ag for the production of ABO abs
3What is the most significant item for transfusion practice?
ABO
4What are the characteristics of ABO abs?
specificity opposite to corresponding ags that are present from RBCs
non-red cell stimulated Abs (prob from environmental exposure)
'expected abs'
5What readily activates normal C' cascade in ABO?
anti-A and anti-B
6What are the results from being transfused anti-A and anti-B?
results of incompatible RBCs are from intravascular hemolysis to potential renal failure to death
7What is the primary foundation of pretransfusion testing?
detection of ABO incompatibility
8What happens to rejected ABO in transplant pts?
incompatible organs could occur leading to graft failure / rejection
9Which population has the highest AB frequencies?
Asians
10What kind of inheritance patterns are ABO?
autosomal co-dominant
11How are the ABO genes passed down?
one ABO gene per parent
12What ABO gene is an amorph?
O (no detectable ag)
13Where is the ABO locus located?
chromosome 9
14What is the ag on RBC for O type?
H
15What are the ab in plasma for O type?
anti-A, anti-B, anti-A,B
16What are the Abs for AB type?
none
17What is the structure of ag on ABO?
carbohydrate structure
18What do glycosyltransferases do?
add individual sugars to sites on sugar chains on the common precursor substance
19What does a common precursor substance produce?
produces H, A, & B ags
20What affects expression of ags?
interaction of ABO, Hh, and Sese gene products
21What is the H precursor substance?
4 sugar chain: Glu, D-gal, N-acetylglucosamine, D-gal
22When is the H ag created?
when L-fucose is present
23What chains can you find the precursor substance?
Type 2 chains Β 1->4 linkage for RBC ag
24What are the alleles in H gene (FUT 1 gene)?
H&h (HH, Hh, hh)
25Which one of the H genes is an amorph?
h (rare)
26Are the H genes inherited alongside ABO?
NO! H genes are independent of ABO genes
27What is required for the production of A or B ags?
H gene
28What do the A and B alleles / genes encode for?
glycosyltransferases
29What is the job of glycosyltransferases?
adds sugar to the H ag
30What does HH / hh genes encode for?
H antigen, leading to ABO blood types
31What does hh (only) gene encode for?
precursor substance
32What sugar does A ag have?
N-acetyl galactosamine
33What does B antigen have?
galactose
34The more A and / or B ags produced …
the more H ag is converted
35What is the density of H ag on a cell?
O > A2 > B > A2B > A1 > A1B
36What is another name for hh?
Bombay
37What is the hh ABO phenotype?
Oh
38What are the RBC antigens on Bombay?
No A, B, or H
39What is the expected plasma abs of Bombay blood group?
POTENT anti-H, anti-A, and anti-B
40Where is H (FUT 1) gene found?
chromosome 19
41Where is Se (FUT 2) gene found?
chromosome 19
42Where is ABO gene found?
chromosome 9
43What are the silent / amorph genes?
h or se
44What is the secretor gene?
Se; H substance found in secretions
45What ags are made if H is present?
A, B, and H on RBCs
46What ags are made if Se is present?
A and B in secretions
47What gene is the non-secretor?
se
48What are the alleles for secretor gene?
SeSe, Sese, or sese
49What do you expect of individual who has Se gene?
A and B ags in gastrointestinal, genitourinary, and respiratory tract secretions as well as milk, sweat, tears, and amniotic fluid (NOT IN CSF)
50What kind of secreted ags are found in Se gene?
mostly glycoproteins (mucins) but also 'free oligosaccharides' in milk and urine
51where are glycolipids found?
imbedded in cell membranes
52Where are glycoproteins found?
secreted into exocrine fluids
53What is the purpose of fructosyltransferase?
adds fucose to make H ag primarily on type-1 chains
54What is the basic backbone of RBC ags?
glycolipids
55What are is the basic backbone of soluble substances?
glycoproteins
56What are the precursor chains for RBC ags?
type 2
57What are the precursor chains for soluble substances?
type 1
58What is the linkage for RBC ags?
β 1→4
59What is the linkage for soluble substance?
β 1→3
60What is the L-fructosyltransferase for RBC ags?
FUT 1 by H gene
61What is the L-fructosyltransferase for soluble substance?
FUT 2 by Se gene
62What happens to sese (20%) secreted ags?
No A, B, or H
63What ABO SeSe or Sese has no A, B, H ag in both ag and secreted ag?
Oh (Bombay)
64Whare the characteristics of Bombay (hh)?
has no L-fucosyltransferase, no H substance (no H ag), no A / B ags, and only precursor substance found on RBCs
65What happens if no L-fucosyltranferase is produced?
no H ag produced, resulting in RBCs with no H, A or B ags
66Will Bombay RBC agglutinate with reagent Anti-A/B, or anti-H?
no! no ags are present
67What is the Bombay blood type ?
O
68What abs will Bombay people have?
anti-A, anti-B, anti-A,B; potent anti-H
69What will Bombay agglutinate?
ALL ABO blood groups
70What are the A subgroups?
A1 and A2
71How many ags / cell does A1 have?
800k-1.2M ag / cell
72How many ags / cell does A2 have?
~250k ag / cell
73What % of A2 have anti-A1 in sera?
1-8%
74What % of A2B have anti-A1 in sera?
22-35%
75What happens if A1 enzyme is more active?
converts most of the H ag to A1 ag
76Why does A1 have more A1 ags / cell?
A1 enzyme transferase is 5-10X more active
77What does A1 have a reaction with?
anti-A and Anti-A1 (lectin)
78What does A2 have a reaction with?
Anti-A only
79What does A1 and A2 encode for?
enzyme N-acetylgalactosaminyltransferase
80What is the purpose of N-acetylgalatosaminyltransferase?
puts an immunodominant N-acetyl-galactose on H ag
81A1A2 genotype →
A1 phenotype
82A2A2 or A2O genotype →
A2 phenotype
83Why do most group A infants appear A2 at birth?
ABH ags not yet fully developed
84What are the weak A subgroups?
A3, Ax, Abantu, Ael
85What results in weak A subgroup?
result of mutant A allele inheritance
86How are weak A subgroups detected?
looking for presence of anti-A1 in sera,
adsorption-elution tests with anti-A,
saliva studies for A and H ags
87What does B allele / gene encode for?
D-galactosyltransferase
88What is the purpose of D-galactosyltransferase?
puts immunodominant D-galactose on H ag
89Does anti-B1 exist?
no, does not exist
90What are cis AB?
A and B genes that are 'next to each other'
91What leads to cis AB?
AB parent + O = AB child (normally offspring would be A or B)
92What mutations lead to cis AB?
single transferase capable of transferring both GalNAc and Gal
93What is required for pt ABO blood type testing?
both pt RBC and the plasma / serum
94What testing is known as 'forward' testing?
RBC testing
95What testing is 'reverse'?
plasma / serum testing
96How are subgroups identified in forward testing?
unknown RBCs + anti-A,B = aggl.?
97How are Bombay identified in forward testing?
unknown RBCs + anti-H= aggl.?
98How are the A subgroup identified in forward testing?
unknown RBCs + anti-A1= aggl.?
99How are lectins identified in forward type?
Anti-A1 (dolichos biflores)
anti-H (ulex europeous)
100What is the group O typing sera?
anti-A,B
101What results do forward types give?
4+ unless subgroup or mixed field
102What does reverse type detect?
abs to A, B, AB, or H
103How are Bombay or unexpected alloantibodies detected in reverse type?
unknown serum + O cells = aggl.?
104What age should reverse typing be done?
above 6 months
105What kind of Ig is ABO abs?
mostly IgM (give strong aggl. At IS / RT)
106What kind of tolerance does ABO abs have?
cold to thermo tolerant
107Do ABO abs cross placenta?
no (mostly IgM)
108What does 'naturally occurring' ABO abs mean?
all normal healthy people have abs to ABO ags which they lack
109What are the ABO abs?
mix of IgM > IgG > IgA
110What happens in ABO abs at 3-6 months old?
missing / low titers of ABO abs due to immaturity (NO REVERSE TYPING!)
111What happens to ABO at 5-10 yo?
adult levels of abs are reached
112What happens at more than 65 yo?
decreased ABO titers due to aging and weakened immune
113What ABO abs are enhanced with enzyme treated RBCs?
IgM and IgG
114What abs are enhanced with lowering temps?
IgM
115What ABO abs are readily inhibited by soluble A or B ags?
IgM
116What ABO ags are inactivated by 2-ME or DTT?
IgM
117What ABO ags are predominant in non-immunized group A and B donors?
IgM
118What are the ABO typing discrepancies?
1. technical / clerical errors
2. RBC reactivity with antisera
3. plasma / serum reactivity with reagent RBCs
119What are possible causes of group I discrepancies?
weak reacting or missing abs
120What conditions can lead to group 1 discrepancies?
chimerism
new born infants
elderly pts
hypogammaglobulinemia
121What leads to group II discrepancies?
weak reacting or missing ags
122What conditions can lead to group II discrepancies?
subgroups A or B
leukemia (excess amount of B)
acquired B phenomenon
123What leads to group III discrepancies?
protein / plasma abnormality leading to rouleaux formation
124What conditions lead to group III discrepancies?
elevated globulin level
plasma expanders
Wharton's jelly
125What leads to group IV discrepancies?
miscellaneous problems
126What conditions lead to group IV discrepancies?
exposure to hidden erythrocyte T ag
cold and warm auto abs
transfused foreign ag
unexpected ABO iso-agg and alloabs
ab other than anti-a and anti-B
cis-AB