Final Exam Flashcards
Which immunoglobulin class is associated with the primary response?
IgM
Which immunoglobulin class is associated with the secondary (anamnestic) response?
IgG
Which immunoglobulin class is also known as incomplete or blocking antibodies?
IgG
Which immunoglobulin class is the predominant class found in the Rh system?
IgM
Explain Landsteiner’s Law.
antibodies will only be present in the serum/plasma if the corresponding antigens are not present on the red cells
What is the difference between a genotype and a phenotype?
the genotype is the actual genetic coding, while the phenotype is the outward expression of those genes
Where are the antigens and antibodies found in the body?
antigens are on the red cells, antibodies are in the serum/plasma
What antibodies naturally occur in group A blood?
anti-B
What antibodies naturally occur in group B blood?
anti-A
What antibodies naturally occur in group O blood?
anti-A, anti-B, anti-A,B
What antibodies naturally occur in group AB blood?
none
What antibodies naturally occur in the blood of Bombay individuals?
anti-A, anti-B, anti-A,B, anti-H
What is the amount of H substance demonstrated on red cells in order of decreasing reactivity?
O > A2 > B > A2B > A1 > A1B
What is demonstrated in forward blood typing?
which blood group antigens are present on the red cells, including Rh status
What is demonstrated in reverse blood typing?
which blood group antibodies are present in the serum/plasma
What is the purpose of performing an adsorption, and what is the difference between auto- and alloadsoprtion?
binds antibody to the red cells in order to remove them from the serum/plasma and better analyze what is left behind; autoadsorption removes autoantibody using the patient’s own red cells; alloadsorption removes certain alloantibodies using non-self red cells, usually as a means of resolving multiple antibodies
What are the five main factors influencing antigen-antibody reactions?
concentration and kind of electrolyte present; pH; temperature; agitation/centrifugation; time
If two homozygous B adults have children, what blood type would their offspring be?
B
Why don’t labs perform reverse blood grouping on newborns?
blood group antibodies are absent in newborn plasma/serum
What are the antisera used in ABO/Rh typing?
anti-A, anti-B, anti-D
Anti-A1 is most often found in individuals of what blood group?
A2
What is one of the best ways to test a patient to see if they have a subgroup or variant of the A blood group?
anti-A1 lectin
Describe the two types of AHG.
polyspecific/broad spectrum - contains anti-IgG and anti-complement; monospecific - contains only one of either anti-IgG or anti-complement
The lectin from which plant has specificity for anti-H?
Ulex europaeus
What is the main purpose for washing red cells used for testing in an antiglobulin test?
removes any unbound IgG or other unbound protein that could potentially interfere with testing
The lectin from which plant is used to distinguish between A1 and subgroup A red cells?
Dolichos biflorus
What is the difference between and IAT and a DAT?
IAT (indirect antiglobulin test, indirect Coomb’s, antibody screen) detects whether red cells are coated with IgG antibody in vitro (outside the body); DAT (direct antiglobulin test, direct Coomb’s) detects whether red cells are coated with IgG antibody and/or complement in vivo (inside the body)
How can cold agglutinins be excluded from a crossmatch?
using the prewarming technique
What is the purpose of anti-A,B antisera?
used to type received donor blood, and to detect A and B subgroups
What type of testing would demonstrate that group A or B fetal cells have been coated with maternal group O antibodies?
DAT or elution (particularly Lui Freeze-Thaw)
What type of antibody does the DAT detect?
IgG
Which rare blood type produces natural anti-H antibodies?
Bombay (hh, Oh)
What procedure can be used to remove Rouleaux?
saline replacement
ABO/Rh antibodies are most often implicated in what serious condition that affect fetuses and newborns?
hemolytic disease of the fetus and newborn (HDFN)
What must be done to a donor unit to firmly establish that it is indeed Rh=?
weak-D testing
When is Rh immunoglobulin (RhoGam, RhIG) given to Rh= mothers?
as an antenatal dose at 28 weeks or at any time during the pregnancy; at delivery of an Rh+, Rh invalid, or Rh unknown baby; any time the mother is suspected to have been exposed to fetal red cells, such as in cases of trauma, fetomaternal hemorrhage, miscarriage, amnicentesis, or cordocentesis
What causes kernicterus in newborns?
hyperbilirubinemia caused by HDFN
What must be done to cord cells before testing, and why?
cells must be washed to remove Wharton’s jelly
What causes HDFN?
antibodies in the mother’s circulation cross the placenta and attack fetal cells; most often due to ABO/Rh incompatibilities
What substances do group A secretors secrete into their saliva?
A and H substance
What substances do group B secretors secrete into their saliva?
B and H substance
What substances do group O secretors secrete into their saliva?
H substance
What substances do group AB secretors secrete into their saliva?
A, B, and H substance
How must an individual inherit the Lewis, secretor, and H genes in order to secrete Leb substance?
LeLe or Lele, SeSe or Sese, HH or Hh; phenotype would be Le(a-b+)
What is the name of for the genes in an individual who genotypes as le, se, and h?
null or recessive
What percentage of the Caucasian population are secretors?
80%
What are the components in a major crossmatch?
donor red cells and recipient plasma/serum
Which antibodies can show up as cold agglutinins?
N, P1, Ii
Which antibodies belong to the Kidd blood group system?
Jka and Jkb
Which antibodies are known for showing dosage when reacting with heterozygous red cells?
MNSs, Kidd, Lutheran, Duffy, Rh (Cc, Ee)
What antigen is known to be sex-linked?
Xga
The i antigen is most prevalent in what population?
children under the age of 18 months
Which antibodies are known to cause delayed hemolytic transfusion reactions (DHTR)?
Kidd
Why is the transfusion of specific blood components preferable to the use of whole blood?
allows targeting of the specific problem with the appropriate component, and also allows many patients to be treated with a single donation
What is the difference between an autologous donation and a directed donation, and what is the biggest advantage of an autologous donation?
an autologous donation is the recipient’s own blood, collected at an earlier date in anticipation of a transfusion, and does not require a crossmatch; directed donations are compatible units that usually come from friends or family members of the recipient, and are collected specifically for that recipient
What is an emergency release?
blood products that are issued without completing compatibility testing at the physician’s request (the physician takes on full responsibility for any consequences)
What is therapeutic phelebotomy and what are two conditions that might require this kind of treatment?
the removal of blood as a means of treating a medical condition, such as polycythemia vera or hemachromatosis (iron overload, or any such condition where circulatory overload is a concern
How often should a new sample be collected on a blood recipient when a series of transfusions are to be administered over the course of several days?
the initial sample should be drawn and tested no more than three days before the first transfusion; the results of this initial test are considered valid for a 72-hour period, after which new samples should be drawn and tested
Why is there a storage limit of 21 days on CPD blood stored at 5*C?
that is how long CPD can maintain 2,3-diphosphoglycerate levels
What is the most common of all transfusion reactions, and what causes it?
febrile non-hemolytic transfusion reaction (FNHTR), cause by recipient antibody reacting to donor cells
What are the two acceptable methods for thawing FFP?
37*C water bath or an FDA approved microwave
What is the name of the government regulatory agency providing licensure for blood banking reagents?
FDA
What does refractory mean and what blood component is it associated with?
unresponsive to treatment; platelets
Which blood component would be indicated for Factor VIII deficiency?
cryoprecipitate
Which blood component would be indicated for marked thrombocytopenia?
platelets
Which blood component would be indicated for Factor V deficiency?
fresh frozen plasma (FFP)
Which blood component would be indicated for exchange transfusion?
whole blood
Which blood component would be indicated for severe burns?
plasma products (albumin, plasma protein fraction, synthetic volume expanders)
Which blood component would be indicated for chronic anemia?
packed red cells
Which blood component would be indicated for acute blood loss?
whole blood
Which blood component would be indicated for hemophilia?
cryoprecipitate (hemophilia A), Factor IX complex (hemophilia B)
