MLT 125 Final Exam Flashcards
Main Ig in primary response
IgM
Main Ig in secondary response
incomplete or blocking antibodies
predominant Ig type found in the Rh system
IgG
Explain Landsteiner’s Law
Ab are present in plasma only when the corresponding Ag is NOT present on the RBC.
Where are antigens found? Antibodies?
on the rbc
in the plasma/serum
Antibodies that are found in the following blood groups: A B O AB
A - anti B
B - anti A
O - anti A, anti B, anti A,B
AB - none
exposure to genetically different AG from same species: transfusion, pregnancy
alloantibody
produced to self Ag; autoimmune diseases; is removed by elution
autoantibody
The amount of H substance demonstrated on the cells in order of decreasing reactivity
O A2 B A2B A1 A1B
Testing for presence or absence of RBC Ag with antisera; looking for what Ag is on pt blood
Forward grouping
Testing for presence or absence of Ab in pt serum with screening cells
Reverse grouping
What is the purpose of performing an absorption?
remove Ab from serum or plasma
List five examples of factors influencing Ag-Ab reactions
Time Centrifugation pH Ag-Ab ratio Temp Ig type Ionic strength medium Incubation time Binding sites
Why don’t labs perform reverse blood groupings on newborns?
RBC Ag isn’t fully developed
Name the antisera used in ABO/Rh
anti-A, anti-B, anti-D
Anti-A1 is occasionally found in individuals of what blood group?
A2
What is one of the best ways to test a pt to see if they have a subgroup or variant of the A blood type?
test plasma/serum with A1 cells
Describe two types of AHG and what is in them
polyspecific; anti-complement and anti-IgG
monospecific; one or the other
The lectin in what plant has a specificity for anti-H?
ulex europaeus
What is the main purpose of washing rbc’s used for testing in an antiglobulin test?
to prevent neutralization of AHG by globulins
The extract from what plant is used to distinguish type A1 cells from other other A cells?
Dolichos biflorus
anti_a1 lectin
The weakest agglutination would be seen with anti-A in what A subgroup?
A3
detects Ab and or complement attached to RBC
useful in detecting HDN, HTR, AIHA
gamma and beta globulins
DAT
detects Ab or complement attached to RBC, in tube testing incomplete Ab to potential donor rbc rbc phenotyping titre Ab screen and compatibility testing
IAT
How can cold agglutinins be excluded in a crossmatch?
prewarm Xm
cold AC
What is the purpose of anti-A1 lectin?
to ID A1 subgroup
What is the purpose of anti-A,B antisera?
to detect subgroups of A that are weaker than A2
What type of test would demonstrate that group A or B fetal cells have been coated with the maternal group O antibodies?
DAT
What type of antibodies does an antiglobulin test detect?
IgG
blocking/incomplete
Which rare blood type produces natural anti-H antibodies?
Oh; Bombay
Name a procedure you could perform in BB to remove rouleaux formation.
saline replacement
ABO and Rh antibodies are most often implicated in what serious condition that affects newborns and fetuses?
HDFN
mother produces IgG alloAb
What must be done to a donor unit to firmly establish that it is indeed Rh =?
weak D test
When is Rh immunoglobulin (Rhogam) give to Rh = mothers?
28 weeks and within 72 hours of delivery
What causes kernicterus in newborns?
infiltration of the brain and spinal cord with unconjugated bilirubin which causes permanent damage to CNS
What type of BB testing is used to detect weak D?
IAT - in vitro
Before testing, what must be done to all cord cells and why?
Wash to remove Wharton’s jelly
interfers with blood typing
What causes HDFN?
Antibodies directed against the Rh Ag D
destruction on rbc of fetus and neonate by antibodies produced by the mother(Rh=).
maternal cells lack Ag that fetal cells have
What substances do the following individuals secrete into their saliva in terms of ABO? A blood group B blood group O blood group AB blood group
A, H
B, H
H
none
How must an individual inherit Lewis, secretor, and H genes in order to secrete Le^b substance?
Le, Se, H
Le, Se, h
You have a patient that has developed Lewis antibodies. What type of donor blood would you want to give them?
Le(a-b-)
Genotypes le, se, and h are said to be what?
recessive
amorphic
What percentage of Caucasians are secretors?
80%
What components are used for testing in a major XM and what is the purpose of this testing?
donor cells to recipient plasma
to ensure safety of transfusion and pt survival
Which antibodies can show up as cold agglutinins?
M, N, I, P1, Le^a, Le^b
Which antibodies belong to the Kidd blood group system?
Jk^a
Jk^b
What antigen is known to be sex linked?
Xg^a
The i antigen is most prevalent in what type of population?
newborns
Which antibodies are know to cause delayed HTR?
Kidd
Why is transfusion of specific blood components preferable to the use of whole blood?
treat many pts with a single donation reduces risk of circulatory overload not wasted reduces reactions "safer" concentrated form of the required fraction can be administered
Name some of the routine testing generally performed on donor blood.
ABO/Rh Ab screen Syphilis Viral resting; HIV, Hep, CMV weak D
self donation
advantage for rare blood types
autologus donation
intended for specific recipient
directed donation
What is emergency release?
an order for blood accompanied by the signed statement of the doctor accepting full responsibility for the transfusion of uncrossmatched, O= blood.
concentrated; small amount of plasma
platelets
5 days
20-24 degrees/RT with agitation
platelets
concentrated cells; small amount of blood
RBC
CPDA - 35 days
1-6 degrees
packed rbc
10 yrs
-65 to -120 degrees
frozen rbc
FFP
fresh frozen plasma
1 yr
-18 degrees
FFP
Cryo
insoluble portion of plasma that remains after thawing FFP
cryo
What is therapeutic phlebotomy? Why is it used? Name two conditions that might require this kind of treatment.
Blood letting
removal of blood from pt with certain conditions; such as polycythemia, hemochromatosis, porphyrias
How long should someone wait between whole blood donations?
8 weeks
How often should a new sample be collected on a blood recipient when a series of transfusions are to be administered over a period of time?
3 days
When transfusing packed rbc what is the total amount (+ or - 10%) that is routinely transfused?
280 mL
Why is there storage limits of 21 days put on CPD blood stored at 5 degrees?
to preserve viability of 70% of red cells post transfusion
List reasons for a permanent deferral from donating blood
IV drug user hemophiliac MS viral hepatitis clotting disorders
What is plasmapheresis?
removal of blood; separation of plasma from blood; rbc returned to donor
What is the most common of all transfusion reactions?
What causes febrile reactions to occur?
Febrile and allergic
leukocyte Ab, sytokines/pyrogen, plt Ab
Name 2 acceptable methods for thawing FFP
FDA approved microwaves
water bath
Which government agency is regulatory agency providing licensure for BB reagents?
FDA
Packed red cells if hepatic seal is broken but unit has been refridgerated
24 hours
Six units of plt have been pooled in an open system
4 hour at 20-24 degrees
FFP has been thawed is refridgerated
24 hours
What is the temp limit for shipping packed rbc?
1-10 degrees
What does refractory mean and which blood component is it associated with?
unresponsive; to plt transfusion
Why are patient specimens kept in the lab after testing is completed and for how long?
in case of concern; transfusion reactions, mis-ID
7 days
Name the methods of good record keeping in the BB
indelible ink
record data in correct log
cross out, date and initial mistakes
How long are most BB records kept in the lab?
12 months
What is the number one source of error in BB
clerical; mislabeling
Factor VIII deficiency
Cryo
Marked thrombocytopenia
plt
Factor V deficiency
FFP
Exchange transfusion
fresh whole blood
Severe burns
human serum albumin
Chronic anemia
packed red cell
Acute blood loss
whole blood
Hemophilia
Cryo
