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74 Cards in this Set
- Front
- Back
What blood group antigens are ENHANCED with enzymes (fiscin, papain)?
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ABO (including Lewis, I, P)
Rh Kidd "A Rhotten Kidd" |
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What blood group antigens are DECREASED with enzymes?
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MNS
Duffy Lutheran "Duffy is destroyed" |
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What blood group antigens are not effected by enzymes?
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Kell
Diego Colton |
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Name the genes responsible for adding a fucose to a Type 1 and Type 2 chain?
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Se gene (FUT2) to Type 1 chain (glycoprotein, found in secretions)
H gene (FUT1) to Type 2 chain (glycosphingolipid |
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Blood group O patient makes what antibodies and why are they significant?
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Anti-A, anti-B, and anti-A,B
** Unlike antibodies from other patients, these are IgG and capable of crossing the placenta. Therefore, ABO is the MOST COMMON CAUSE OF HDN (though ABO expression is weak in the fetus so it's usually not that bad) |
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Blood group A or B patient makes what type of antibodies?
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IgM, warm reacting
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What are the warm reacting antibodies?
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Rh, Kidd, SsU, Duffy, Kell
Usually IgG, require exposure |
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What are the cold reacting antibodies?
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ABO, Le, MN, P, I
Usually IgM, naturally occur, usually clinically insignificant |
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What % of A people are A1?
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80%
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What lectin agglutinates A1 but not A2?
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Dolichus biflorus
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What lectin agglutinates H?
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Ulex europaeus
(thus... O & A2 patients will react most) |
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What blood group antigen is the point of entry for H pylori and Norwalk virus?
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Lewis b
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What type chain is the Lewis antigen system built on?
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Type 1 (in secretions & adsorbed onto the RBC)
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can a person be Lewis b+/a-?
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No
One Lewis gene If Lewis b, you don't make anti-Lewis-a because you have Lewis a it is just outnumbered |
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What neutralizes Lewis antibodies?
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Saliva from secretors
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What gene is required to make Lewis b?
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Se gene (80% of people)
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What % of people are Le(a-b-) by ethnic group, and thus make naturally occurring anti-Lewis-b, which also has H specificity?
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22% Af Am
6% Wh **Le(a-b-) in kids increases susceptibility to UTI with EColi, candida |
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Auto-anti-I associated with?
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Mycoplasma pna
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Auto-anti-i associated with?
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EBV
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Adults that lack I are usually what ethnicity? Classic association?
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Asian
Cataracts, HEMPAS (CDA2) |
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Point of entry for parvovirus?
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P antigen
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What neutralizes P antibodies?
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Hydatid cyst fluid
Pigeon egg white |
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What is the Donath-Landsteiner antibody?
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Auto-anti-P = IgG
Binds in the cold, hemolyzes in the warm Causes PCH******** Classically associated with syphilis & viral infection in kids |
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What is the main P group antigen?
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P1 is the ONLY real antigen
Most common phenotype is P+, P1+, Pk- |
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What can happen if someone lacks all 3 P antigens
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Get anti-PP1Pk
Acute HTR & HDN & SPONTANEOUS ABORTIONS |
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H + what = A blood group?
B? O? |
A: N-acetylgalactosamine
B: galactose O: nothing! just H antigen |
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What antibodies does saliva neutralize?
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ABO
Lewis |
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What antibodies does serum neutralize?
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Chido, Rogers
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What antibody does urine neutralize?
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Sda
|
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What is the genotype of a Bombay individual?
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hh/sese
lack both H and Se genes Look like O on testing |
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What antibodies does a Bombay individual make?
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Anti-A
Anti-B Anti-H *** Must use Bombay donor for blood |
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What is the acquired B phenotype?
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In a patient that is blood group A, exposure to enteric gram negative organisms can strip off the N-acetyl group and appear to have WEAK expression of B antigen.
These patients FORWARD type as AB, reverse as A |
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What lectin is helpful in diagnosing acquired B?
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BS1 lectin. will NOT agglutinate acquired B.
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What is the Parabombay phenotype?
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hh but some Se
Can make A and B chains (if they have the genes) in secretions but not on RBCs. Will naturally make ALLO-ANTI-H so must use Bombay donor |
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What is the order of blood type among Caucasians?
African Americans? |
C: R1 > r > R2 > R0
A: R0 > r > R1 > R2 |
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Peripheral blood finding in Rhnull?
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stomatocytes
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Peripheral blood finding in McLeod?
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Acanthocytes
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Important facts about Kidd
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Jka > Jkb
Fixes complement! (unusual for an IgG) Marked dosage effect (and therefore usually NOT associated with HDN) Wanes over time = classic anemnestic response, DHTR |
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Are Rh antibodies IgG or IgD?
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IgG
Warm reacting Require previous exposure Extravascular hemolysis |
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If a blood donor tests as D negative on routine testing, what must be done?
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Test for weak D with an IAT
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Do weakD moms need Rhogam if they have a D+ baby?
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No.
This is different than partial D moms, who do need prophylaxis |
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What is weak D and what are the common causes?
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Quantitative defect in D antigen
Usually a point mutation in RHD OR a "C in trans" (RHCe on opposite chain) can inhibit D expression |
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What is partial D and what are the causes?
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Qualitative defect in D antigen
RHD mutations affecting the exterior of the D antigen; people can form antibodies to the missing parts of D On testing, will find anti-D in a D+ patient |
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What is the f antigen?
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Present when ce is inherited together (r, R0)
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What would you suspect if a D- patient gets anti-D, anti-C despite no exposure?
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G antigen. This is present when either C or D is present.
Must give C-D- blood |
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What chains make up the MNS system, and what bug are they receptors for?
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Glycophorin A (MN)
Glycophorin B (SsU) P. falciparum! |
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Are M & N antibodies IgM or IgG?
Is their activity increased, decreased, or no change with enzymes? |
IgM! cold reacting, naturally occurring, usually insignificant
Decreased (DUFFY, MNS) |
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Are S,s,U antibodies IgM or IgG?
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IgG
warm reacting requiring exposure significant |
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What is the lectin for N?
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vicea graminea
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What is more common:
M or N? S or s? U? |
M = N
s>S U is UNIVERSAL |
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Because glycophorin B "looks" like the N antigen, most people will not form N antibodies even if they are N-. Exception?
Why do we care if someone makes Anti-N - aren't these clinically insignificant? |
2% of African Americans lack glycophorin B. They can't make S,s, or U (!!!!). Thus the presence of an anti-N antibody is a marker for someone that might be able to make an anti-U, which would be very very bad, since U is universal
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Auto-anti-N seen in?
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Hemodialysis
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Duffy. IgG or M?
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IgG (warm, exposure, significant)
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Fy (a-, b-) resistant to?
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P. vivax.
68% AA |
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Cold reacting antibodies
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ABO, lewis, I, P
MN |
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Do we care about kell?
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YES. Can cause severe HDN, AHTR
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Which is more common: K or k?
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k. High frequency (~99.8%!)
K is low frequency (9%Wh, 2%AA) Anti-K is common and VERY important |
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What is Kx?
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Not a true antigen. Structural. When Kx decreases, Kell antigens decrease too.
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What is McLeod phenotype?
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Absence of Kx. All kells are decreased. Make anti-Kx.
Hemolytic anemia with acanthocytes Myopathy, ataxia, neuropathy, cardiomyopathy Associated with CGD!!!!!!! (infections with staph) |
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Name 2 HTLA (high titer, low avidity) antigens?
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Chido
Rogers |
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These antibodies show dosage
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Kidd (Jk)
Rh (except D) Duffy MNS |
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What are the carbohydrate antigens? What are their features?
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ABO
Lewis I P Naturally occurring IgM Cold reacting Agglutinating (i originally thought M&N were in this group but apparently not) |
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What chromosome are the genes on that code for ABO?
Rh? |
9q
6 |
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Ceppelli effect
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Weak D due to C in trans
More common in African Americans |
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If someone is anti-E, what else are they probably?
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Anti-c
Common practice to give E neg, c neg blood to someone with anti-E. (R1 blood has this) Anti-c is a common cause of DHTR |
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How to destroy a Kell antigen?
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ZZAP it! (also DDT)
They are otherwise unaffected by enzymes |
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HTLA antibodies that are usually clinically significant
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Cartwright
Holley Gregory |
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Breastmilk neutralizes what antibody?
Guinea pig urine? |
I
Sda |
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Rh(null) affects what blood antigens?
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Lack LW, Fy5
Weakened S,s,U STOMATOCYTOSIS |
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What genes are located within the MHC complex in chromosome 6?
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HFE (hemochromatosis)
TNF 21-hydroxylase complement |
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What is the approximate risk of a serious in utero hemorrhage in a fetus affected by NATP?
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50%
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Dosage
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MNS
Kidd Duffy CcEe |
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Which antigen is made when altered by bacterial neuraminidase?
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T, Tn, Tk
Transience & goes away post infection Cad is a rare inherited antigen |
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Polyagglutination
type of antibody? test? |
T, Tn, Tk, Cad
IgM Naturally occurring IgM antibodies in adults the test is that they are agglutinated by adult but not cord serum |