Unit 3 Flashcards
What is the cutoff age for child bearing age in women
50
What does the H antigen do?
Which blood type has the most H antigens
gets lycosylated to become A or B, it is a precursor
most- O type
What genotype tend to make it so that not all H is converted to A or B
What blood type would hh give us?
What can blood products can we give someone that is hh why?
AO or BO
hh does not make any precursor, no ABO gene expressed
can only give hh because regular O has H and would cause transfusion
What does the Se gene do?
What does the Le gene do?
What does the H gene do
Se- converts a into b -in blood
Le-makes lewis a - in saliva
H- gives lewis b a place to bind to on RBCs
Are ABO antigens fully developed at birth?
When do ABO antibodies develop?
What blood testing is done on cord blood specimen?
What temp? What Ig/ heavy chain
no, they develop by 5-6 weeks of gestation
6 months after birth
only forward, no abs yet no need for plasma
cold, IgM
T or F ABO antigens decrease over time until they go away
F- they decline with age but always stay as naturally occuring IgM-cold
What temperature associated with IgG? and IgM? Which is more likely to give us problems with HDFN
Warm-IgG
Cold-IgM
Warm-HDFN
What antibodies do O people make? B? AB? A?
O-anti A, B
B-anti-A
A-anti-B
AB- no antibodies
Put the anti ABO in order of most violent response to least
Anti-A worse than Anti-B
In an emergency an A person needs plasma, what options are NOT an option
cant give them B FFP. it has anti A antigens
What plasma products can you give
O
A
B
AB
O->O, A, B, AB
A->AB and A
B->AB and B
AB-> AB
Which antibodies can cross the placenta
IgG
How do you transfuse D antigens
O+? What can they receive from RBCs
O-
A+
A-
B+
B-
AB+
AB-
if D + —> can be either + or -
if D - —> can be ONLY -
O+ —> O+ , O-
O- –> O-
A+ —> A-+ , O-+
A- —> A- , O-
B+ —> B+- , O+-
B- —-> B- , O-
AB+ —-> AB+ , O+- , A+-, B+-
AB- —–> AB-, O- , A-, B-
What plant is used to imitate anti H
anti-H europaeus
What plant is used for the anti A lectin
Dolichous biflorus
What blood groups have the most H antigen concentration? put in order least to greatest
O>A2>B>A2B>A1>A1B>Oh
What if we add anti-H to someone that is
Bombay?
not Bombay?
Bombay- negative- no agglutination
Not bombay- positive-agglutination
What are the 3 main reasons there are ABO discrepancies
technical error
properties of RBCs -forward type issue
properties of plasma/ serum- reverse type issue
What type of discrepancy and how are the results affected
-antibody coated RBC
-Cold agglutination
-mixed field reaction
-Acquired B antigen
-Forward type-False positive
-reverse type
-2 different blood types-forward type
-forward type- bacteria in gut create B similar antigen
all extra reactivity
What type of discrepancy, how are the results affected
- missing or weak RBC antigens
-age- neonate or elderly
-antibody coated RBCs-post/ pro zone
-forward
-reverse
-forward-pro/ post
Explain what Wharton’s Jelly is and how to fix it
Excessive proportions of serum proteins in cord blood. Causes spontaneous agglutination
forward type usually the issue- can fix with saline wash
if not, check patient history
looks like AB in forward but A in reverse
patient is A
What is acquired B antigen?
Aquired B when bacteria in gut look like anti-B
Rouleax and unexpected antibodies other than ABO will cause _____ reactions
Weak or missing isoagglutination will cause ___ reactions
extra, positive reactions
negative missing reactions
What blood types cause cold allogenic or cold auto antibody reactions, what typing results indicate this issue
LIPMAN
do an auto control
if +- auto ab
if - allo ab
allo-
M, P1, Le^a, Le^b, A1 or A2B
auto
anti-H, anti-A1, anti A1B
What blood products are most important for Rh compatibility
platelets
How do we look for weak D antigens in people
monoclonal anti-D antisera
if the Rh control is positive,
Must do a weak D test
only detectable with IAT using AHG
Who will always be tested for weak D
donors and newborns, if anti-D is negative
Why do people have weak D?
positional gene effect: D allele is in trans to C allele
true D mosaic: genetic loss of D nucleotides make the D antigen missing
If someone has a true mosaic D, will they react to getting transfused with D blood?
20% of people will make anti-D if they are exposed to D+ blood through transfusion or pregnancy
What are compound antigens
two antigens need to be expressed for a “new” antigen to be created
What compound antigen is this and how often can it cause HDN or transfusion reactions? What is the rule? Which one is positive? Which one is negative?
-Dce/dce
-DCe/DcE
-DcE/dCe
-Dce/ DCE
F antigen Rh6
c and e in cis
-Dce/dce +
-DCe/DcE -
very rare
G antigen Rh12
D and C antigens in cis
-DcE/dCe -
-Dce/ DCE +
How can you find the G antigen?
perform adsorption and testing with R2R2 and r’r cells
What population is most affected by the V antigen? what is the Rh number for it?
V antigen
Rh10
black population
What is the Rh null phenotype
Rh antigens missing from RBC surface
if transfused with any Rh+ RBCs, they can form antibodies for every Rh antigen
How and why does Rh null phenotype occur
lack a common promotor or regulator gene and it leads to a lack of Rh expression
The gene for Rh is there but not expressed
Also possible to acquire it from anemia, macrophages can view Rh as foreign in the spleen and destroy Rh antigens
