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Blood bank I-blood groups

STUDY
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what are the 2 stages of agglutination
1. coat cells (sensitization)
2. formation of bridges (Ab & RBCs)
What is the direct lysis of RBC as a result of Ab coating called?
Hemolysis
What Ig is the best at fixing complement?
IgM (pentamer)
What is the phase that has pt serum + 2-5% RBC solution in a tube, centrifuge and examine?
Immediate spin phase
What is the most common combo of pt serum and RBCs for tube testing?
2 drops serum, 1-2 drops RBCs
True or False: it Ab rxts in IS phase they are clin sig Ab?
False
WHat phase duplicates body temp, takes mixture, incubates at 37C for a specified time, centrifuge and examine?
37C phase
How long do you incubate the mix with LISS?
10-15min
How long do you incubate the mix with PEG or alb?
15-30min
How long do you incubate the mixture with no Ab-Ag enhancers?
30-60min
What is the indirect antiglobulin test (aka Coombs test, Antihuman globulin)?
wash mix of pt serum and RBC solution to remove unbound Ab
Add AHG (look for something coating RBCs)
centrifuge and examine
What is a positive gel test result?
no button, gets stuck in gel as RBC Ab bind to column
What is positive solid phase result?
A lawn of RBCs coating the well bound to Ab in the well
What is an negative solid phase result?
A button
What is the test where UNCOATED RBC + Ab is put together, washed, AHG added and examined?
INDIRECT Antiglobulin test
What is the test where you take the RBC's directly from the pt, wash unbound Ab, add AHG and examine?
DIRECT Antiglobulin test
What 3 uses can you use the IAT for?
1. check for unknown Ab (RBCs + known Ag profile-ie Ab scrn)
2. check for unknown RBC Ag (serum + known Ab specif--ie RBC Ag test)
3. check for rxting unknown Ag AND unknown Ab--ie crossmatch
What is the specific AHG that detects RBC coated with either IgG or C3d and may detect other Ig?
Anti-IgG,-C3d (polyspecific)
What is the AHG that detects IgG and light chains assoc c other Ab classes (IgM, IgA)?
Anti-IgG and anti-IgG (heavy chains)
What is the AHG that detects complement components, is good for IgM related hemolysis and certain WAIH w/o IgG?
Anti-C3b,C3d
What are the 3 specificities of AHG?
1. Anti-IgG, C3d
2. Anti-IgG, anti-IgG (heavy chains)
3. Anti-C3b, -C3d
What test do you do to make sure your DAT or IAT reagent is working if you get a negative DAT or IAT?
Coomb's control
How does the Coomb's control work?
add IgG coated RBCs to the mix you had for the IAT
if test negative, bad AHG or didn't add AHG
What blood group Ab exhibit dosage?
Rh
Kidd
Duffy
MNSs
What is the neutralizing substance for ABO?
saliva
What is the neutralizing substance for Lewis?
saliva
What is the neutralizing substance for Sda?
guinea pig urine
What is the neutralizing substance for P1?
Pigeon egg fluid or hydatid cyst fluid
What is the neutralizing substance for Chido, Rodgers?
serum
What does a blood group being clin sig mean?
causes HDN, HTR
What are the 5 traits of a warm reacting Ab?
1. IgG
2. clin sig
3. require exposure
4. cause HDN
5. cause HTR
What are the 5 traits of a cold reacting Ab?
1. IgM
2. not clin sig
3. naturally occurring
4. no HDN
5. no HTR
What is the one exception to the rule of the warm and cold reactive Ab?
ABO, it's cold reactive and IgM but clin sig
Name the blood groups enhanced by enzymes like papain and ficin?
Lewis Is A Rhotten Peeing Kidd
ABO, Lewis, I/i, P, Rh, Kidd
What are the blood groups destroyed by enzymes?
Duffy, MNSs
What are the blood groups unaffected by enzymes?
Kell (kell doesn't care about enz)
What are type I ABO blood group chains composed of and where are they found?
Glycoproteins.
Found in secretions.
What are the type II ABO blood group chains composed of and where are they found?
Glycosphingolipids
Found on RBCs
What ch is the secretor gene on?
Ch 19
What Ag can a person make if they are a secretor?
A or B Ag in their secretions (ie saliva)
What does an Se gene add to a Type I chain and where?
Adds FUCOSE to type I chains at the TERMINAL GALACTOSE
What is the product of an Se gene adding fucose?
H Ag
What % of pop can make H Ag on Type I chains?
80%
What ch is the H gene on?
Ch 19--closely linked to Se gene
What does the H gene do?
Adds FUCOSE to TERMINAL GALACTOSE ON TYPE II chain
What is the product of the H gene?
H Ag
What % of pop can make H Ag with H gene?
100%
What has to be on type II chains before A or B Ag can be made on RBCs?
H Ag
What is required on Type I chains before A or B can be made in secretions?
Type I H (H Ag)
How many sugars have to be added to H Ag chain to make an A or B Ag?
One
What is added to the terminal galactose to make A Ag?
N-Acetylgalactosamine
What is added to the terminal galactose to make B Ab?
Galactose
What happens to the amount of H Ag when you make A or B Ag?
more A or B, less H (reciprocal relationship)
What is the amount of H in each blood group in order of decreasing freq?
O>A2>B>A2B>A1>A1B
What ch has the genes for the ABO blood group?
Ch 9
Are ABO clincally significant and naturally occurring?
Yes, the exception to the cold/IgM "rule"
What is the universal dOnOr?
Group O
What is the most common blood group?
Group O
What is the genotype for O?
OO
What is the Ag for O?
H
What lectin agglutinates cells with H Ag?
Ulex europaeus
What Ab are on O?
Anti-A and Anti-B
Are group O Ab IgG or IgM?
IgG, so can cross placenta
Can Group O cause HDN?
Yes, mild HDN--MOST COMMON CAUSE OF HDN!!!!
What is low in group O?
vWF
What is the genotype for group A?
AA, AO
What are the antigens on A?
A, H
What are the Ab on A?
Anti-B; it's an IgM so no cross placenta
What are the subgroups and % of A?
A1 (80%) and A2 (20%)
How much more A is on A1 than A2?
4x more A Ag on A1
What does a small % of A2 form Ab to?
Anti-A1, clin insig but screws up ABO testing
What lectin agglutinates A1?
Dolichos biflorus; use to ddx A1 from A2
What is the genotype for group B?
BB, BO
What are the Ag on B?
B, H
What are the Ab on B?
Anti-A
What lectin agglutinates B?
BS-1
What group is the universal recipient?
AB, least freq blood type (~4%)
What are the Ag on AB?
A and B (very little H)
What are the Ab on AB?
None
What are the two types of ABO testing?
forward grouping (cell typing)
reverse grouping (back or serum typing)
Which ABO test uses pt's RBC (Ag), add known anti-A and anti-B sera?
Forward grouping (tells you pt RBC type)
Which ABO test uses pt's SERUM/plasma (Ab), add known A1 and B RBCs?
Reverse grouping (tells you pt Ab)
If a pt has forward Anti-A and reverse B cells agglutination what is cell type?
A
If pt has forward Anti-B and reverse A1 cells agglutination what is cell type?
B
If a pt has forward Anti-A and B and no A1 or B agglutination what is cell type?
AB
If a pt has no forward Anti-A or B and + A1 and B what is cell type?
O
What is the relationship of ABO forward and reverse typing?
Opposite, if not, discrepancy
Serum and cell typing are required unless what 2 reasons?
1. baby < 4 months old
2. reconfirming testing done elsewhere (just do cell/fwd typing)
What are ABO discrepancies usually due to?
Ab and Ag probs
What are the main Ag probsin ABO typing discrepancies?
1. Lack of expected Ag
2. Presences of unexpected Ag
What reasons do you get lack of expected Ag in ABO typing?
1. A or B subgroups
2. txp or transfusion
What reasons do you get presence of unexpected Ag in ABO typing?
1. Acquired B phenotype-colon ca, G- sepsis
2. recent marrow/stem cell txp
3. nonspecific polyagglutination
What are reasons you get lack of expected Ab in ABO typing?
1. immunodef
2. immunocompromised, elderly, neonate
3. really high [ ] of Ab-->prozone effect
3. txp or tranfusion
What are reasons you get unexpected Ab in ABO typing?
1. Anti-A1 (from A2 pts)
2. rouleaux
3. cold auto/alloAb
4. txp or transfusion
What is the pt's real blood type in acquired B phenotype?
A
What does an acquired B look like forward and reverse typing?
Forward: AB (weak + in B)
Reverse A
When bact deacetylate A so it looks like B (term galactose) and the remaining galactosamine cross reacts with Anti-B what is that?
Acquired B phenotype
How do you fix an acquired B to get the right results?
A's:
Acidify serum
Acetic acid (re-acetylates)
Autoincubation (no rxn)
Bs-1 lectin (no rxn, only rxn with real B)
What is the B(A) phenotype's real ABO group?
B, tests forward like AB (weak A)
What type of phenotype rxts with a particular form of Anti-A?
B(A) phenotype, to fix just use diff Anti-A
What phenotype looks like an O but doesn't make ANY Ag?
Bombay (Oh)
How does the ABO typing look in Bombay?
Forward: O
Reverse: O
Ab scrn is WILDLY + and all units incompatible
What do you transfuse Bombay pts with?
Only other Bombay donors
What does ParaBombay have that Bombay does not?
Se, partially compensates for lack of H
How does the ParaBombay ABO typing look?
Forward: O
Reverse: H and A or B Ag (unless group O), have anti-H in serum
What blood group is the most freq cause of blood bank fatalities?
ABO
What is the most freq cause of HDN?
ABO, mild
What is a consequence of ABO incompatibility?
Severe acute hemolytic transfusion reactions--death
How many genes are in the Lewis blood group?
one; the Le gene
What type of chains are in Lewis?
Type I chains only
How is Le a Ag made?
gene pdct adds FUCOSE to SUBTERMINAL GlcNAc
In a non-secretor what is the only type of Lewis Ag?
Le a
How is Le b Ag made?
1rst: Se gene adds fucose to term galactose->makes type I H
2nd: Le gene adds fucose to subterm GlcNAc->Le b
b is the 2nd letter of the alphabet, b goes on 2nd
Are the majority of secretors Le a or b?
Le b
Which Le adsorbs better to RBC surface?
Le b is BETTER, that's why most adults that are Le and Se are Le (a-b+)
Do Le (a-b+) pts have Le a?
yes, not all chains converted, just can't detect on RBCs
T or F, the same chain carries Le and ABO Ag?
True
Which Le is more freq a or b?
Le b (b is better)
22% of blacks have what Le Ag?
Le (a-b-); 6% of whites have this
What types of Ab are the Lewis?
Naturally occurring
cold reacting IgM
What neutralizes Lewis?
Saliva
What are consequences of Lewis incompatibility?
None really, no Le Ag on fetal RBCs
What happens to Le Ag during pregnancy?
Decreases, can have transient insig Le Ab
If pt is Le (a-b+) do they have anti-Le a?
no, they still have Le a too, just not detected on RBC surface
What type of Le seen in kids?
Le a >b, varies w age as Ag chains get converted
What uses Le b to attach to gastric mucosa?
H. pylori
What Le phenotype is seen in kids with increased UTIs?
Le (a-b-)
What are the 5 major Ag of the Fisher-Race blood group?
D, C, E, c, e
What makes up a haplotype?
DCE, Dce, etc
What is the Fisher-Race haplotype for the Wiener classification system for R1?
DCe
What is the Fisher-Race haplotype for the Wiener classification system for R2?
DcE
What is the Fisher-Race haplotype for the Wiener classification system for R0?
Dce
What is the Fisher-Race haplotype for the Wiener classification system for Rz?
DCE
What is the Fisher-Race haplotype for the Wiener classification system for r?
dce
What is the Fisher-Race haplotype for the Wiener classification system for r'?
dCe
What is the Fisher-Race haplotype for the Wiener classification system for r"?
dcE
What is the Fisher-Race haplotype for the Wiener classification system for r y?
dce
What is the most to least common Wiener in whites?
R1>r>R2>R0
What is the most to least common Wiener in blacks?
R0>r>R1>R2
What types of Ab are Rh?
Warm reacting IgG
Exposure required
What are consequences of unexposed Rh- pts?
80% chance develop Ab after 1U of RBC Rh+ blood
What are consequences of exposed Rh- pts that have Anti-D?
HTR with EXTRAvascular hemolysis
What blood group causes most severe HDN?
Rh, give RhoGam
What is the test needed to detect weak D phenotype?
need IAT to detect D Ag in D+ pts
What are reasons for weak D?
C in trans (C on opp ch to D)
mosaic partial D, lack portions of D Ag
What test is required of all blood donors?
IAT (weak D test) for ALL D- blood DONORS
What phenotype has hemolytic anemia with stomatocytes, associated altered activity of S, s and U and no Rh Ag at all?
Rh null
What is a less severe form of Rh but also has hemolysis?
Rh mod
What causes a warm autoimmune hemolytic anemia?
Ab specific to basic Rh struct Ag
Where do you find G Ag on Rh?
Whenever C or D present
Where do you find f Ag on Rh?
When c and e are on the same ch (ie r or R0)
What are the Ag in Kidd?
Jk a and Jk b
Which Kidd Ag is more common?
Jk a (this is the exception to the rule of B)
What type of Ab is Kidd?
Warm reacting IgG
Exposure required
Very good at fixing complement (unusual for IgG)
What 2 blood groups show dosage?
Duffy and Kidd
may not react at all with heterozygous Kidd Ag; react VERY strongly to homozygous Kidd Ag
What is unique about the Kidd Ab?
disappears with time and storage
What is Kidd's most famous association?
Delayed HTR: anamenstic response
What type of hemolysis does Kidd assoc HTR have?
INTRAvascular--see schistocytes
Does Kidd cause HDN?
Yes, mild HDN, mild due to dosage effect
What type of glycophorin carries M or N Ag?
Glycophorin A (these are the 1rst 2 letters in the group, A is 1rst)
What type of glycophorin carries S,s,U Ags?
Glycophorin B
What is more freq M or N?
equal freq
What is more freq s or S?
s>S
What do 2% of blacks have as a phenotype in the SSU Ag?
S-, s- and U-
bad, U is universal
What are the M and N Ab?
cold IgM (Anti-M gen insig but has been assoc w HDN)
naturally occur
dosage
insig
What are the S, s and U Ab?
warm IgG
require exposure
min dosage
sig
Do enzymes destroy M, N, S, and s?
Enz destroy M, N, S NOT s Ag
Why don't M+ N- pts make anti-N?
N-like Ag ('N')
What is the Ag that is on glycophorin B that has the same term 5 AA as glycophorin A's last 5?
N-like Ag
Who makes Anti-N?
blacks that are S-, s-, and U- since they don't have glycophorin B
What MNSs Ab is induced by formaldehyde sterilization of the hemodialysis machine?
Anti-N, formaldehyde modifies N Ag
What lectin agglutinates N Ag?
Vicea graminea-used commonly as N typing agen
What blood group has HUGE racial differences?
Duffy
What are the Duffy Ag?
Fy b and Fy a
What Ag is more freq in Duffy a or b?
Fy b
What Duffy phenotype is resistant to P. vivax and P.knowlesi?
Fy (a-b-)
What race has Fy (a-b-)?
68% blacks, protects against malaria
What Duffy Ag is more common in Asians?
Fy a (a in Asians)
Which Duffy Ab is more common and more sig?
Fy a
What are the Duffy Ab?
Warm reacting IgG
require exposure
marked DOSAGE
What are the consequences of Duffy incompatibility?
Severe HTR-usually delayed and EXTRAvascular
Which blood group is unaffected by enzymes?
Kell (Kell doesn't care)
What Kell Ag is low freq?
K (aka K1) 9% whites, 2% blacks
What Kell Ags are high freq?
k (aka K2) 99.8%
Js b
Kp b
What is the relationship of Kx ot Kell Ag?
Kell Ag decrease, Kx increases (Kell Null phenotype aka K0)
When Kx is decreased what are Kell Ag?
Decreased also
What destroys Kell Ag?
thiol reagents: 2 ME, ZZAP, DTT
What is the most common Ab after Anti-D?
Anti-K, warm reacting IgG
What type of Ab is anti-k?
Warm reacting IgG
uncommon due to high Ag freq
What are the consequences of Kell incompatibility?
Severe HTR acute or delayed, EXTRAvascular
Severe HDN
What is the phenotype with NO Kell Ag, high Kx and sig anti-Ku w exposure?
Kell null (K0)
What is the complete absence of Kx Ag and markedly decreased but not absent Kell Ag, no anti-Ku, hemolytic anemia and acanthocytes?
McLeod phenotype
What dz is McLeod phenotype assoc with?
Chronic Granulomatous Disease
-X linked recessive
-NADPH oxidase deficient
-organisms phagocytized but not killed
-catalase + organisms (Staph)
Where is the Lutheran (Lu a and b) Ag located?
Ch 19 linked to Se
What is an Ag seen in 90% of females on ch X?
Xg
What blood type is 2 pairs of Ag: Di a/Di b, Wr a/Wr b
Diego, Anti-Wr a common, insig
What blood group has a high freq, refractile immune complexes andis neutralized by guinea pig urine?
Sd a
What lectin agglutinates Sd a?
Dolichos biflorus
What are HTLA (high titer low avidity) Ag with high freq, neutralized by serum?
Chido, Rodgers
Which blood group Ab are IgG and sig?
Rh, Kidd, Kell, Duffy, SsU, PCH (IgG)
Where do you see Big I blood group?
Adults
Where do you see little i?
kids, big I in big people, little i in little people
Big I has what type of chains?
branched
Little i has what type of chains?
simple
What type of Ab is I/i?
Cold Igm
naturally occurring
autoAb very common
What is the classic assoc with big I?
Mycoplasma pneumoniae infection
cold agglutinin dz (IgM)
What is the classic asso with little i?
Infectious mononucleosis
less often autoAb
What is the most freq P Ag?
P1 (P1+, P+, Pk-)
If you have no P (rare) what happens if you get a P product?
Acute HTR
HDN
Early abortion
What Ag is assoc with Parvovirus B19?
P Ag is the Point of entry for Parvovirus (P Ag is Parvovirus B19 receptor)
What are the P Ab?
Cold reacting IgM
naturally occurring
What neutralizes P Ag?
Pigeon egg and hydatid cyst fluid
What type of Ab is assoc with Paroxysmal Cold Hemoglobinuria?
IgG--biphasic hemolysin, binds in cold, hemolyzes when warmed
What is the name of the biphasic hemolysin seen in PCH?
Donath-Landsteiner
Who gets PCH?
Classically assoc with syphillis but nowadays it's kids s/p viral infxn