#2 Flashcards
How do you calculate how many units need to be screened to find 2 units:
2 / % neg frequency = units need to screen
if more than one Ab, multiply neg frequencies
The administration of 8-10 units in less than 24 hrs, OR acute administration of 4-5 RBC units in one hour :
Massive Transfusion
Neonatal transfusion is specific to neonates under ____ months old, and should be compatible with any ____ antibodies:
4 months
maternal
What is used to detect spontaneous agglutination in the DAT:
saline control
What is the purpose of the washing steps in the IAT:
to remove free globulin
Lewis antigens are formed on Type__ paragloboside via ___linkage, and found in _____:
type 1
1:3 linkage
body secretions
Lewis blood group gene found on chromosome___:
19
What class Ab are Lewis:
IgM
T/F
Lewis antigens are often involved in HTR and HDN:
False. They are usually IgM and cannot cross the placenta.
Lewis antigen is formed by adding a ___:
subterminal fucose
Lewis antigens on RBC via ____:
glycoprotein
Lewis antigen in body fluids via___:
lipoprotein
To form Lewis-b, you must have the __ gene add a ___ fucose, and the Le gene then add a _____fucose:
Se, terminal fucose
Le, subterminal fucose
Are Lewis antigens an integral part of RBC membrane:
No, they are found in secretions and adsorbed onto cells
Lewis antigens are not well developed at ___, and will decrease during _____:
birth
pregnancy
T/F
Lewis antigens decline during pregancy, and the mother may produce antibodies:
True
Which Lewis antibody is associated with renal failure w/ BM transplants:
Le-a
Which Ab is associated with H. pylori:
Le-b
T/F
Lack of both Le and Se is associated with certain pathologies:
True
List the 5 antigens that are typically IgM:
Le-a/Le-b Lu-a I M P N (think 'llimpn')
List the 5 antigens that are primarily IgG:
Kell Kidd Duffy Lu-b S,s (think 'kkdls')
What does HTLA stand for:
High Titer Low Avidity
Does Anti-M react with complement:
No, it is IgM
___ is common in children, seen in bacterial infections, and typically IgM:
Anti-M
These two antibodies form on GPA:
Anti-M
Anti-N
Which antibody can be formed in dialysis patients, and how is it denoted:
Anti-N (due to the formeldahyde)
Anti-Nf
Anti-S/s are usually of this class:
IgG
Which antibodies form on GPB:
Anti-S/s
Anti-U
Which is more common, Anti-M or anti-N:
Anti-M is more common
P-like antigens have been found in these kinds of birds:
pigeons and doves
also bovine liver fluke and earthworms
T/F
There are several theories of how P antigens are formed:
True
Which P antigens are thought to be formed on a naked precursor:
P, pk
List the gene that codes for the following antigens:
P:
P1:
pk:
P: P2 gene
P1: P1k gene
pk: p1k or pk gene
P1 antigen is formed on this:
Precursor type 1 or 2
Which of the P antigens are IgM, which are IgG:
IgM: Anti-P1
IgG: Anti-P, Anti-PP1pk
Anti-PP1pk is also known as____:
Anti-Tj-a
____ is an inseperable mixture of 3 Ab’s, is rare, can be IgM or IgG,a nd is significant in HDN, HTR, chronic abortions, organ rejection:
Anti-Tj-a (aka Anti-PP1pk)
pp phenotype:
lack of antigens
If p is amorphic, how does one develop Anti-p:
Ab reaction with unmodified precursor of P antigens
Which P antibody can be allo or auto as well:
Anti-P
- AlloAb Anti-P: if patient is pk
- AutoAb Anti-P: cold agglutinin
This antibody is typically Igm, is cold and weak reacting, associated with taperworms, and is a ParvoB19 receptor:
Anti-P1
Anti-P1 is typically ___, is a receptor for____, and is associated with ____:
IgM
ParvoB19
taperworms
In order to have Luke antigen, you MUST have __ antigen also:
P
You cannot have ___ antigen without P:
Luke
This antibody is associated with Hodgkins Lymphoma:
Luke
Anti-I/i are usually of this class:
IgM
___ is associated with Mycoplasma pneumoniae:
Anti-I
Anti-I is associated with _______:
Mycoplasma pneumoniae
Which antibody is associated with EBV, alcoholic cirrhosis, and myelogenous leukemia, is usually IgM:
Anti-i
If you test Anti-I against cord blood, what is the result? what about against adult red cells:
Cord blood: negative
Adult cells: positive (anti-i)
Is there a gene for I/i production:
No, they are part of the ABO family, formed on same precursor chain
___ antigens are defined by a series of carbohydrate chains on inner portion of proteins, change via increased branching:
I/i
When is I antigen detectable:
~18 months, continues to increase
List the Kell antigens:
K/k
Js-a, Js-b
Kp-a, Kp-b
Which Kell antigens are high incidence:
k (Cellano)
Js-b
Kp-b
What is the silent Kell allele:
Ko (will make Anti-Kell)
Will the silent Kell allele make Anti-Kell:
Yes
Why are Ab’s to high frequency antigens rare:
because so few lack antigen
Why are Ab’s to low frequency antigens rare:
because so few are exposed
Which are well developed at birth, Kell or lewis:
Kell
Do Duffy antigens store well:
No
Fy(a-b-) is prevalent in ______ and is protective against ____:
african-americans
malaria
Is Fy(a+b+) more prevalent in caucasians or african americans:
caucasians
What class are Duffy Ab’s, and do enzymes enhance or destroy:
IgG
enhance
Are antibodies to Xg-a common:
No, because antigen is high frequency, antibodies are rare
List those diminished/destroyed by enzymes:
Duffy’s
M N S/s
Xg-a
List those enhanced by enzymes:
P Lewis I Rh Kidd
____ is often found in Polynesians:
Kidd-null
What are the two ways Kidd-null can occur:
- amorph Jk
* Suppressor gene (InJk= Jk inhibitor)
List the Kidd antigens:
Jk-a Jk-b
Jk-3
Jk-a-Jk-b
List two reasons Kidd antibodies evade detection::
- Low titers
* poor storage
It is very important to have a fresh sample when testing for this antibody:
Kidd
Anti-Jka/b
Which antibodies are associated with delayed transfusion reactions:
Duffy
Kidd
XS1+SYN-1A is the regulator gene for the ___ gene:
Lutheran
T/F
Lutheran antigens are well developed at birth:
False.
Which phenotype of Lutheran is high frequency:
Lu(a-b+)
____ antibodies are usually IgG, but can be IgA or IgM:
Lutheran
Why are Lutheran antibodies minimal in HDN:
because they are poorly developed at birth
If an individual inherits lele, will they express Le-a/b?
No
To express Le-b, an individual must inherit these 3 genes:
Le
H
Se
An individual who inherits Le, Se, and H genes (either homozygously or heterozygously) will express __ on ___, Secretions will have ______:
Le-b on RBC’s
Secretions will have Le-a and Le-b
With Se gene, H antigens will be _____:
in plasma and secretions
If an individual inherits Le and either sese or hh, then that individual will express only ___ in secretions and on RBC’s:
Le-a
Le-b individuals have ___ in small amounts in plasma and do not generally produce ____:
Le-a
Anti-Le-a
Le(a-b-) individuals commonly produce _____:
Anti-Le-a
What is the ISBT number for ABO:
001
What is the ISBT number for Rh:
004
Which antigen is associated with HLA/platelets:
Bg
Are P, Tj-a, and Colton-a high or low frequency antigens:
High frequency
This blood group takes ~7 years for the antigen to fully develop:
P group
Colton Ab’s could cause ____ damage:
kidney
___ and _____ (both ‘other’ blood groups’) are poorly expressed on cord cells and are depressed during pregnancy:
Cromer and Indian
HLA are white cell antigens, when on RBC’s are known as:
Bg antigens
___ have varying amounts of HLA’s, and can be used to absorb Bg antibodies:
Platelets
Le, Se, A/B/H genes = what in secretions::
Le-a
Le-b
A, B, H
*phenotype: A,B,H, Le(a-b+)
Le sese A/B/H genes= what in secretions:
Le-a
*phenotype: A,B,H, Le(a+b-)
Le, sese, hh, A/B = what in secretions:
Le-a
*phenotype: O(h), Le(a+b-)
A/B and hh genes gives what blood type:
O(h)
bombay, no H gene, so not A or B
Lewis substances in saliva are _____:
glycoproteins (and are not adsorbed onto the RBC membranes)
Lewis _____ are what is in plasma:
glycolipids
Cord blood will type Le(a b ):
Le(a-b-)
*not detectable in the plasma until about 10 days
When Anti-P1 is suspected, you could incubate the tests at ____ to enhance reaction, since it is Ig class ___:
room temp
IgM
All individuals with p and pk phenotype are _____:
Luke-
Strong antibodies to ___ have been found in bird handers and patients with bovine liver fluke disease (fascioliasis):
P1
Auto Anti-P is associated with _____:
Paroxysmal Cold H
How does complement aid in the identification of alloantibodies masked by anti-Ch(a)?
C4d in plasma will absorb anti-Ch(a)
Bg antibodies are primarily directed toward antigenic determinants present on what type of cells?
White Blood Cells
Why are the M and N antigens important for paternity testing?
Antigens are well developed at birth
What characteristic differentiates Ss antigens from MN antigens?
enzyme degradation
Anti-i is found in association with what disease?
infectious mononucleosis
The Ii antigens are found on the membranes of which structures?
Platelets
White Blood Cells
Red Blood Cells
Which antigen is expressed on C4B complement fragments?
Ch(a)
Dosage is most commonly seen with what blood groups?
Kidd, Duffy, Rh, MNS
Enzyme unaffected antigens:
Kell blood group
Secretor gene is on which chromosome?
Chromosome 19
How many people have Se gene?
80%
What percent of blacks are Le (a-b-)?
22%
____ is associated with autoimmune diseases (RA, SLE), large amounts of transfused plasma products have resulted in severe _____:
Null Chido/Rodgers
anaphylaxis
This antibody group can be neutralized with concentrated urine, serum, or plasma containing the antigen:
Cromer
This blood group system antigens are found in serum, plasma, urine, plts, wbc’s, and placental tissue, but is poorly expressed on cord cells and depressed expression during pregnancy:
Cromer
This blood group system has antigens on Complement Receptor 1 (CR1):
KNOPS
What is REST used for, and what is the procedure:
It is used to absorb cold Ab’s (usually Anti-I)
*add rabbit cells to pt serum, rabbit cells absorb cold Ab’s from pt serum
What is a positive DAT detecting in a baby:
Detects mom’s Ab’s agains baby’s D antigen, passively acquired via crossing the placenta
Major vs Minor Crossmatch:
Major: pt serum + donor RBC’s
Minor: donor plasma + recipient RBC’s
Crossmatch is done to confirm ____:
ABO compatibility
shows up at IS
Type & screen tests for :
ABO
Rh
Ab screen
What is the most common cause of error in pretransfusion testing:
misidentification of the recipient
List the 3-4 naturally occuring Ab’s:
Lewis
M, N
P1
(Lu-a)
Lewis, M, N, P1, and Lu-a are immune or naturally occurring antibodies:
naturally occuring
List the cold-reacting Ab’s:
Lewis M, N P1 Lu-a I
What phase of testing do Rh, Kell, Duffy, Kidd, S/s, and Lu-b react at:
AHG
Delayed transfusion rxn, think ____:
Kidd
Define ‘acceptable probability’ in antibody detection:
- at least 3 cells positive for the antigen, which react w/ pt serum
- at least 3 cells negative for the antigen, which do not react w/ pt serum at which the Ab is directed
Which Ab class is detected at IS phase:
IgM
Which Ab class is detected at Albumin, 37 C phase:
IgG
Which phase detects clinically significant IgG Ab’s:
AHG (aka coombs reagent) phase
*Rh, Kell, Duffy, Kidd
Most fatal transfusion reactions are caused by ___:
clerical error
Is compatibility testing required for plasma products:
no
For fetal transfusions, compatibility testing is performed using _____:
the mother’s sample
Transfusions for infants should be compatible with both ___ and ___:
mother and baby
T/F
Samples must be collected within 3 days of transfusion:
true
Information should be verified at least ___ before the blood product is transfused:
twice
What is the most critical pretransfusion serologic test:
ABO typing
Naturally occuring Ab’s are the result of ____:
environmental factors
A ___ Ab is one that is transferred to the patient through blood products or derivatives:
passively acquired
The ___ antigens are carried on the DAF and are distributed in body fluids, urine, etc:
Cromer
Which blood group has the most severe and prototypical HDN?
Rh
How can anti-N be induced?
Hemodialysis –> formaldehyde sterilization of the machine –> modification of N ag
Which Duffy ag is more common in Asians than in caucasians?
Fya
Unique features of Duffy:
- Fya-b- –> Malarial resistance
- Fya-b- humans are resistant to Plasmodium vivax and Plasmodium knowlesi - Dosage
- Variable expression
In the ISBT system, the first three digits represent ____, the last 3 digits represent ___:
the system
the antigen
Lewis Ab’s are frequently encountered in ____:
pregnant women
Are Lewis Ab’s considered significant for transfusion medicine:
No
The SsU phenotype is found in the ___ population:
black
Patients with ______ infections may develop strong cold agglutinins with auto-anti-I specificity:
Mycoplasma pneumoniae
A rare phenotype described as decreased Kell system antigen expression:
McLeod (causes granulomatous disease)
Are I and I antithetical?
no, they have a reciprocal relationship
Allo-anti-P is found as a naturally occurring alloantibody in the sera of ___ individuals and is clinically significant:
Pk
allo anti-P —> PCH
