ABO blood group Flashcards
TRUE/FALSE
ABO is considered the most important of all blood grouos
TRUE
TRUE/FALSE
HTR is common in ABO
TRUE
*Severe
TRUE/FALSE
ABO is the most common cause of HDN
TRUE
ABO Forward typing other names
Front/ Direct typing
specimen for Direct/Front typing
Patient RBC
Reagent for Direct typing
commercial anti-sera
Anti-A sera is color ____
Blue
Anti-B sera is color ____
Yellow
what is detected ABO Forward typing?
ABO antigens
Principle of ABO Forward typing?
Agglutination
Reaction of blood groups to Anti-A and Anti-B sera
A: A(+), B(-)
B: A(-),B(+)
AB:A(+),B(+)
O:A(-),B(-)
Principle of ABO Reverse typing
Agglutination
other terms for ABO Reverse typing
Backward/Indirect/Serum typing
specimen in ABO Reverse typing
serum/plasma
reagent used in ABO Reverse typing
Known A cells, Known B cells
ABO Reverse typing is for the detection of
ABO antibodies
Reaction of blood groups to known cells
A: A(-), B(+)
B: A(+),B(-)
AB:A(-),B(-)
O:A(+),B(+)
Blood type rich in H antigen
blood type O
RELATIONSHIP between forward and reverse typing
Inversely proportional
centrifugation time for ABO typing
20 seconds
Grading agglutination reactions:
Several large agglutinates
few free cells
clear supernatant
3+
75%
Grading agglutination reactions:
many tiny agglutinates
may free cells
may not be visible w/o microscope
dark, turbid supernatant
W+
weak +/-
Grading agglutination reactions:
no agglutinates
no aggregates
dark, turbid, homogenous supernatant
0
Negative
Grading agglutination reactions:
many small agglutinates
many free cells
turbid supernatant
1+
25%
Grading agglutination reactions:
one large, solid agglutinate
no free cells
clear supernatant
4+
100%
Grading agglutination reactions:
a few isolated aggregates, mostly free floating cells, supernatant appears red
mixed field
“halo” or “puff smoke”
mixed field
causes of mixed field
receiving non-ABO-type specific RBCs, ABO subgroups (A3), and bone marrow or HSC transplantation
ABO GENOTYPE OF THE FF.:
A1 A2 A1B A2B B O
A1 = A1A1,A1O,A1A2 A2 = A2O,A2A2 A1B = A1B A2B = A2B B = BB,BO O = OO
ABO genes found in chromosome
chromosome 9
dominant genes
A and B
Amorph/silent
O
Enzyme for H
L-fucosyltransferase
Enzyme for AB
N-acetylgalactosyltransferase
D-Galactosyltransferase
Enzyme for A
N-acetylgalactosyltransferase
Enzyme for B
D-Galactosyltransferase
Immunodominant sugar of A
N-acetyl-D-galactosamine
immunodominant sugar of O
none
Immunodominant sugar of AB
N-acetyl-D-galactosamine
D-galactose
Immunodominant sugar of H
L-fucose
Immunodominant sugar of B
D-galactose
antigens for the following:
A B AB H O
A = A B = B AB = AB H = H O = unchanged
precursor structure on which A and B antigens are made
H antigen
TRUE/FALSE
The H and Se genes are part of ABO blood group system
FALSE
TRUE/FALSE
The H and Se genes influence inheritance of A and B antigen expression
TRUE
Linkage of Type 1
beta 1,3
linkage of type 2
beta 1,4
origin of type 2
Erythrocyte precursors
origin of type 1
plasma/secretions
antigen present in A1
A, A1
Reaction of A1 with anti-A1 lectin
+
80% of the A population
A1
1-8% of A2 produces _____
Anti-A1
22-35% of A2B produces ____
Anti-A1
source of anti-A1 lectin
Dolichos biflorus
A subgroups with (-) reaction on anti-AB
“MYel”
Am
Ay
Ael
source of anti-B lectin
Bandeirea simplicifolia
higher titer compared to anti-A or anti-B alone
Anti-AB
A1 and A2 subgroups were described by
von Dungern
principle for detection of secretor status
Hemagglutination inhibition
(+) result for hemagglutination inhibition
no agglutination
most common to least common blood group
O > A > B > AB
TRUE/FALSE
ABH can be seen in tissues and secretions
TRUE
composition of ABH antigens on RBC
Glycolipids, glycoproteins, glycosphygolipids
composition of ABH antigens on secretions
glycoproteins
ABH substance in saliva of A
A and H
ABH Substance in saliva of B
B and H
ABH Substance in saliva of O
H
ABH Substance in saliva of AB
A, B, and H
ABH Substance in saliva of nonsecretor
none
ABO antibodies may be
IgG
IgM (Predominant)
IgA
5th phenotype
BOMBAY (Oh)
do not inherit the H gene
BOMBAY (Oh)
Landsteiner’s Law
1) if Ag is already present on the RBC , the corresponding Ab must be absent from the plasma
2) If Ag is absent on the RBC, Ab must be present on the plasma
ABO antibody production begins at _____ and peaks at _____
3 - 6 months ; 5 - 10 years
only forward typing is performed on
Newborns
*they can’t produce antibodies yet, until they are 3-6 months or older
a person’s blood type is his/her ____
Phenotype
principle of detection of Secretor Status
Agglutination-inhibition
positive result for detection of secretor status is
NO AGGLUTINATION
Show weaker reactivity with commonly used antisera
ABO subgroups
seed extracts that agglutinates human cells
Lectin
reported by Bhende in 1952 in Bombay, India
Bombay phenotype (Oh)
Bombay phenotype
Oh
Bombay genotype
hh
blood transfused to Bombay must be
from another Bombay (Oh)
most common discrepancy
Group I Discrepancy
unexpected reactions in the Reverse grouping due to weakly reacting or missing antibodies
Group I Discrepancy
unexpected reactions in the Forward grouping due to weakly reacting antigen
Group II Discrepancy
Caused by protein or plasma abnormalities and result in Rouleaux formation or Pseudoagglutination
Group III Discrepancy
Caused by Miscellaneous problems
Group IV Discrepancy
Group III Discrepancy resolved by
Washing
acquired B phenomenon is only seen in ______
group A persons
Group I Discrepancy resolved by
history; enhance reaction by incubation or addition of plasma
Group III Discrepancy common in
Wharton’s jelly
plasma expanders
elevated fibrinogen
elevated globulin (Multiple Myeloma, Waldenstrom’s macoglobulinemia)
Group I Discrepancy common in
newborns elderly px with leukemia hypogammaglobunemia immunosuppressed
Group II Discrepancy common in
Acquired B phenomenon
Subgroups A or B
BGSS
Hodgkin’s disease
to detect true or acquired B
Acidified anti-B antisera
Acidified anti-B antisera pH
pH 6.0
only blood group that affects Clinical transplantation
ABO
-sugars that occupy the terminal positions of this precursor chain and confer blood group
specificity
immunodominant sugars
beta 1 → 3 linkage
secretion
type 1
beta 1 → 4 linkage
rbc
type 2
represent phenotypes showing weaker and variable serologic reactivity with the commonly used human polyclonal antiA, anti-B, and anti-A,B reagents
ABO SUBGROUPS
A subgroup demonstrated by
von Dungern
show increased reactivity with anti-H lectin compared to A1 RBCs
A2 RBCs
chir=merism
presence of 2 cell population in an individual
inheritance of both AB genes from one parent and an O gene from another
Cis AB