Blood Group Shit Flashcards
ERYTHROCYTE ANTIGENES AND ANTIBODIES
A blood groups system is a group of ______ encoded by _____ at a _______ gene locus or at gene loci _______ that _______ does not occur
antigens; alleles
single; so closely linked
cross over
ERYTHROCYTE ANTIGENES AND ANTIBODIES
An antigen collection is a group of antigens that are _________________________________________ but ______________________
phenotypically, biochemically or genetically related
their genes are not known to be allelic.
International Society of Blood Transfusion has recently recognized ____ blood group systems.
Apart from _______ and ________, many other types of antigens have been noticed on the red cell membranes.
______ antigen collection have been defined generally.
34; ABO and Rhesus system
7
Immunology of the blood group system.
An antigen is a substance that can _______, when introduced into an immuno competent host and can ___________
evoke an immune response
react with the antibody.
Most blood group antigens are ________ and their specificity is mostly determined either by the ________ (e.g. ABO) or ____________(e.g. MN, Kell, Duffy, Kidd, Diego)
glycoproteins
oligosaccharide
amino acid sequence
Specificity of an antigen is determined by _________ and _______________ with its _______
its structure
stereochemical fit with its antibody
An antigen can have several ________ or ____________ with each epitope capable of eliciting an antibody response.
epitopes or antigenic determinant
The ability of an antigen to _____________ is called immunogenicity
stimulate an immune response
Antigen’s ability to _____________ is called its antigenicity
react with the antibody
So, ____,____,______ and the _______ and _______ of the epitope on the red cell membrane affect these immunogenicity and antigenicity
size, shape, rigidity
number and location
Antigen expression
_______-labelled _____ and _____ conjugated _____ is used to estimate number of antigenic site.
125I; antibody
ferritin; anti-IgG
Antigen development
Most erythrocyte antigen are detected early in fetal development
T/F
T
erythrocyte Antigen development
ABH = ____-____ in fetal development
5- 6wks
Antigen development
all erythrocyte antigen however are fully developed at birth
F
Not all erythrocyte antigen however are fully developed at birth
Adult expression of ABH, I and lewis antigen may take _______
2yrs
Adult expression of ______,_____ and ______ antigen may take 2yrs
ABH, I and lewis
Lutheran and P1 adult development may take > ________
7yrs
_______ and ______ adult antigen development may take >7yrs
Lutheran and P1
Genetic variation
Homozygous individual may have (more or less?) number of antigen site than heterozygous for a particular allele and May possess (stronger or weaker?) reaction with the antibody (i.e dosage) allelic antigen like Cc, Ee, Kk, Mn, Ss, Jka and JK5 usually show dosage
Dosage is less with D and lutheran
More
Stronger
Haplotype ________ and _______ can affect phenotype expression (e.g inheriting ___ with ____ can suppress expression of D)
pairing and gene interaction
C; D
Immunogenicity
After ______ and _____ , ____ is the next immunogenic followed by ____ and ____
A and B
D
K and C.
BIOCHEMISTRY OF ANTIGEN
An antibody will recognise
1)4-5 ___________ resided on _______
or
2)1 -7 _____ resided on _______
Amino acids sequence; linear polypeptide
sugar; linear polysaccharides
BIOCHEMISTRY OF ANTIGEN
Polysaccharides are made by ______ addition of __________ by _________
sequential
specific sugars by specific transferase enzymes
sugars involved in red cell antigens are:
- _________
2.___________ - ___________
4.__________
5.N-acetylneuraminic acid (sialic acid) and - D-manose
D- galactose
N-acetyl D-Galactosamine
N-acetyl-D-glucosamine
L-fucose,
CARBOHYDRATE ANTIGENS
_________________ blood group antigens are examples of Carbohydrate antigens.
P, ABO and Lewis
CARBOHYDRATE ANTIGENS
Their specificity depends on ______ or ___________ sugar, the type of polysaccaride to which the sugar is attached and on the type of linkage
terminal or immunodominant
CARBOHYDRATE ANTIGENS
_______________ is the immuno- dominant sugar for A and P antigen
__________– for B, P1 and Pk
_______ for substace H, Lewis
N-acetyl-D-Galactosamine
D-galactose
fucose
CARBOHYDRATE ANTIGENS
N-acetyl-D-Galactosamine is the immuno- dominant sugar for _____ and ____ antigen
D-galactose – for _____,_____, and _____
fucose for ______,_______
A and P
B, P1 and Pk
substace H, Lewis
In the ABO system, the ___ antigen encodes the gene that encodes, for the transferase enzyme.
The ABO locus is located on chromosome ____ at
The H-antigen gene is located on chromosome _____ and expressed as a ______ containing glycan
I
9
19
fucose
PROTEIN ANTIGEN
-______,_____,______, and ______ are all glycoylated protein
__________ antigen are non- glycocylated protein
MNS, Kell, Duffy and Lutheran
RH and kidd
PROTEIN ANTIGEN
- MN: Resides on ________ (with 131 ass and 15-G-linked oligosaccharide chains)
glycophorin A
The RH protein is especially hydro______ and transverse the red cell membrane the RH.
The gene coding for the RH antigen are located on _______ loci on long arm of chromosome ___(_____-_____)
phobic
two gene
1
p36-p34
DISTRIBUTION OF RED CELL ANTIGEN IN HEALTH AND DISEASE
RH, Kell, Duffy and Kidd antigens are found only on red cell so also is MNS and Lutheran except. Lub (on renal endothelial cell and liver hepatocytes)
MN activity is seen on renal capillary endothelium
DISTRIBUTION OF RED CELL ANTIGEN IN HEALTH AND DISEASE
____,_____,_______ and _______ antigens are found only on red cell
so also is ______ and _______ except. _____ (on __________ and _________)
RH, Kell, Duffy and Kidd
MNS and Lutheran
Lub
renal endothelial cell and liver hepatocytes
MN activity is seen on renal capillary endothelium
T/F
T
Physiologic disorders of red cell antigen and some observed associated medical conditions
ABH are found on endothelial cells and epithelial cells except for these of the _________.
ABH, Lewis I and P blood group antigen seen in _______,_______, And _______
CNS
plasma, platelets, lymphocyte
Physiologic disorders of red cell antigen and some observed associated medical conditions
Blood group A = carcinoma of ____,_____,______,_______ and also with thrombosis.
blood group o: ______,_______,______,______.
non secretion of ABH is associated with __________
salivary gland , stomach, colon and ovary
duodenal ulcers , gastric ulcers , rheumatoid arthitis, vWD
Candida Albicans
Erythrocyte that lack Duffy (Fya and Fyb ) antigen are ________________ (_________)
not infected by malaria parasite (P vivax)
Rhnull syndrome (an autosomal recessive condition characterized by ______________________ is associated with ____________________
complete lack of all Rh antigens
hereditary stomatocytosis
Mcleod phenotype: resulting from decreased expression of the 23 _____ blood group antigens with absence of the ________ antigen on red cell
i.e the ____ synthesized by _____ on the ___ chromosome is lost due to a mutation…
kell
xK
xK protein ; Xk gene; X
this xk protein interact with the _______ to help _______ the RBC membrane. And also protect _________ functions.
cytoskeleton
stabilized
neurological
McLeod phenotype
This patient are:
Mostly (male or female?)
Have defect in _____ transport
___________cytosis
After ____yrs they develop a progressive form of _________
are associated with deletion on the X-chromosome at position XP21.
Male ; H2O
Acantho
40; muscular dystrophy
Gerbich Negative phenotype
•(_____ type)
•lacks _____ or ———
•Tend to have _____cytosis
•Have weakened expression of ____ blood antigen.
All these are associated with ________
leach
glycophorin C or D
elipto; Kell
haemolytic Dx
Bombay Phenotype: presents a serious problem in blood transfusion practice. They ____________ and thus develop __________
lack substance H
anti-H antibodies
RED CELL ANTIBODIES
Classification
Based on target site:
_____-antibodies
______-antibodies
Auto
Allo
RED CELL ANTIBODIES
Classification
In terms of mode of sensitization
___________ – usually ________ from substance similar to red cell antigen
________ antibodies
Naturally occurring
hetero agglutinin
Immune
RED CELL ANTIBODIES
Classification
In term of optimal temperature
Cold – ___-____oc
Warm – ______oc
2-4
37
RED CELL ANTIBODIES
Classification
TYPES
Ig____ is the immune type red cell antibody, receptors or macrophage in the liver
G
spleen removes Ig__ coated red cell from circulation.
G
IgG anti RBC antibody are capable of complement fixation
T/F
T
Arrange the IgG anti RBC antibody in order of decreasing capability to fix complement
IgG 3>IgG1>IgG2>IgG4
Binding to complement by IgG antibody is determined by
________
____________________
Surface density
Location of the recognized antigen
Binding to complement by IgG antibody is determined by:
Surface density
Location of the recognized antigen
Why?
This is because C1q requires that at least two IgG molecule bind to a red cell within a span of 20-30nm to initiate the complement cascade
IgG-anti-D often bind complement
T/F
F
IgG-anti-D rarely bind complement
IgG-anti-D rarely bind complement because _________________; and the epitope is _______________
most D sites are spaced too far apart
so small that only one anti –D molecule per epitope can bind
- Most IgG anti ABH antibody agglutinate saline suspended red cell
T/F
F
Most IgG anti ABH antibody do not agglutinate saline suspended red cell rather they sensitize red cell at 37oc and can be detected with the help of AHG.
IgG antibody crosses placenta.
IgM antibody crosses placenta.
T/F
T
F
IgG antibody crosses placenta.
IgM is a pentamer, does not cross the placenta.
Ig__ and Ig___ can agglutinate red cells and activate complement effectively
G
M
Note both haemolytic and agglutinating abilities of antibodies can be destroyed by ___________ or _________
dithiothreitol or 2-mercaptoethanol
Low affinity IgM may agglutinate red cells only at temp _________%
Meaning they bind to red cells at _____ temperature and dissociate at ____oc)
below 37
low
37
Ig____ is the primary antibody in secretion
A
IgA Exist predominately as _____ with a secretory component there in
dimers
IgA
Does not cross placenta
Does not fix complement
T/F
T
T
aggregated IgA can activate ______ pathway of complement
Multmeric IGA antibodies in serum are as __________ in serology tent and are associated with ___,_____,______ activity
alternate
haemaglutinins
A, B or Lutheran
IgG levels in fetal circulation rise between _________ -_______ as the selective transport system matures in the placenta
actual fetal antibody production begins ______________ (all detected antibodies in fetus are ______)
low levels of Ig___ followed by Ig___ and Ig__ develop several weeks after birth (Anti A and Anti B takes _________)
22-23weeks
shortly after birth
maternal
M; G; A
2-6month
Naturally occurring allo-antibodies are mostly associated with ______ antigen (____,_____,_____)
They occur in person ___________________________
carbohydrate
ABO, Lewis and P
lacking the corresponding antigen
Immune antibodies are found mostly in ______________________ individual
multiply transfused
CLINICAL SIGNIFICANCE OF RED CELL ANTIBODY
1. Haemolytic transfusion reaction:
Intravascular
Immediate transfusion reaction:_______
Delayed:______ (Jka, JKb)
ABO
KIDD
CLINICAL SIGNIFICANCE OF RED CELL ANTIBODY
1. Haemolytic transfusion reaction: Extravascular:
IgG1 and IgG3 reacting at ——- temperature(IgG antibodies of _______,_____,_____,_____,______ antigen) and these make up the bulk of clinically significant antibodies
body
Rh, Kidd, Kell, Duffy or Ss
Haemolytic Disease of the newborn a.k.a ___________
Ig___ and Ig____ which crosses placenta are mostly implicated
erythroblastosis fetalis
G1; G3
HDN
Aetio-pathogenesis
1.______ related
2._____ related
3. other red cell antigen/antibody
Rhesus; ABO
Rhesus Related HDN
•
1. sensitization of rhesus ____ mothers by previous blood transfusion using _____ donors, ____ transfusion or other means which leads to ______ of Rh ______ fetus, abruption placenta etc
negative; Rh + ; fetal
abortions; positive
Rhesus Related HDN
Is the (more or less?) severe phenotype
With reason
More
because Rh antigens are more concentrated on red cells and fully developed in-utero
Rhesus Related HDN
critical titer is ___:____ which would lead to _________
1:32
fetal hydrops
ABO related HDN
affects women with blood group ______ with a ________ of _________ and a fetus with blood group _________
O+
high titer of immune anti A or B.
A or B.
ABO related HDN
it is usually (more or less?) severe
With reason!!
Less
ABH antigen is widely distributed on virtually all nucleated cells
ABO is not fully developed till after birth
HDN: Other red cell antigen/antibodies
Over ____ other red cell surface antigens have been implicated in HDN (E.g Kell, duffy- -Fya). However only anti-____ and anti- ____ (K1) are associated with severe disease.
Critical value for k1 is ___:____
50
Rhc; kell
1:8
Clinical features of HDN
_______ skin
_________ amniotic fluid, umbilical cord and eyes
Enlarged______ or _______
Hydrops fetalis( _______,______,______)
____________
Pale skin
Yellowish
liver and or spleen.
massive edema, heart failure and organomegally
kernicterus
Laboratory features of HDN
___________
_______________
Peripheral blood film:_____________ features
_________
Anaemia
Thrombocytopaenia
erythro-leucoblastic
polychromasia
diagnosis of HDN
________
________________ sampling
_________
Amniocentesis
Percutaneous umbilical cord blood
ultrasonography
treatment of HDN
Prophylaxis (maternal after a ______ test)
________ transfusion
Early_______
______therapy
Exchange blood transfusion
Intravenous _________
Keilhauer
Intra-uterine
delivery
immunoglobulin
______ antigen is a typical example of a haplotype
Rhesus
Rhesus antigen has 2 different loci that has 2 different set of alleles
One by _____
One by ______
D
CE Or Ce Or ce Or cE
Absence of ___ = Rhesus negative
D
Which is more antigenic??
A or B
A
Which is more immunogenic ??
B or D
B
___________ is the baseline glycoprotein
Substance H
Substance H is the raw material from which ______ is formed
ABH
Substance H is located on chromosome ____
9
Substance H is located on the same loci on chromosome 9 as the AB antigen
T/F
F
Different
Substance H circulates in the blood and attaches to the _____ membrane and as well as any ___________ cell
Rbc
Nucleated
Erythropoietin acts on already committed stem cells
T/F
T
Red cell antigens are formed with the membrane
T/F
F
They are not
Dosage phenomenon:
Antigenicity of _____zygous > Antigenicity of _____zygous
Homo
Hetero
A group of genotype that are closely linked together = ___________
Haplotype
In the case of ______ on the loci of ____________ genes, where __________ , The H antigen ____________
Hence this people have H blood group
mutation; enzyme producing
the enzyme isn’t produced
remains unremodelled
_________ and ________ are pure proteins
Rhesus
Kidd
________ phenotype is usually mistakenly grouped as blood group O
Bombay
Bombay phenotype
Production of ______,______,_____
Anti-A
Anti-B
Anti-H
Which is better, agglutinin or hemolysin?
Agglutinin
agglutinin is to Ig__
As
hemolysin is to Ig__
M
G
Young RBCs are usually resistant to _____
HCL
Anti-Rhesus C is just as severe as RH HDN
T/F
T
Anti-Rhesus preparation = ______
Rhogam D
