141 terms

Blood bank questions

Which blood group has the most H substance?
Anti A and Anti B are produced by what?
Ingestion of bacteria, food, pollen
Why are cells washed in the AHG phase?
Remove traces of unbound serum globulin
What is the zeta potential?
Net charge of cell and ionic cloud that travels with the cell, Want to lower the zeta potential for BB reactions, protein weakens the zeta potential
Will there always be agglutination if an antibody attaches to a Red cell antigen
No; cells may be sensitized
What is prozone?
Antibody excess
What part of the antibody attaches to antigen?
If more cells are added than drops of antisera, is this a prozone or postzone?
What is the purpose of centrifugation?
Pushes cell closer together
Will shaking the cell button too hard cause a false = or false +?
False negative
What about too heavy of a cell suspension?
False negative
What are check cells?
D+ cells with anti D added
What are the most common blood types?
A and OAutosomal co dominant
How are blood group antigens inherited?
Autosomal co dominant
When are check cells added?
All negative AHG reactions
Can the specific antibody be determined from the screening cell antigram?
No can however make an educated guess
What blood type are screening cells?
Group O
What does titer mean?
ABY concentration capable of binding RBC antigens
What cell processes the antigen? Produces antibody
T cells; plasma cells
What does sensitized red cell mean?
Antibody attached but no agglutination
Are we only interested in agglutination reactions?
No we want to see if antibody or complement is attached
What specimen is used for ABO typing?
Pt red cells
Will nucleotide base pairing with a template made from nuclear DNA direct the amino acid to line up in the proper order to form a protein?
Wll A2 serum react with A2 cells?
Is Anti A, B reagent made from an AB person?
What could happen if a group O person receives group A blood?
Is Complement a protein?
When is lectin used
Resolves ABO disrepancies
What does titer mean?
Amount of Antibodies produced
Do most dA2 people make Anti A1?
No only if exposure to A1 cells
8% make antibodies to A1
Facts about screening cells antigram
Cannot definitely ID the antibody
Cannot determine the pt blood type
reaction at AHG is clinically significant
Detects IgG
When should a D mosiac be suspected?
When a D+ person makes Anti D that is nonreactive with their own cells
When is dosage observed?
Homozygous cells will have a stronger reactions than will heteroygous cells
What is the next step if the ABY screen is positive?
Perform a panel
What is the purpose of an elution?
Removes the antibody from cell membrane
What is the purpose of neutralization?
Inactivates the ABY by binding the antibody to a soluble antigen
With what are check cells coated?
If a recipient is B+ (Weak D+), transfuse with what?
B+ blood
Could a B+ Du+ develop anti D if the person is a mosaic?
If high protein anti D is used and both the Du and control are positive, what does this indicate?
Invalid Rh
What is the cause of a positive Du control?
Positive DAT
If high protein anti D is used, how should a positive Du and Du control be resolved?
Use monoclonal/polyclonal D antisera
What if the above problem is not resolved?
Give Rh negative blood
Can anti Leb cause HDN? Is it clinically significant?
No won't cause HDN; it is IGM so not significant
Can anti Lewis B be neutralized?
Yes; Lewis A and B and P can be neutralized
Is Lewis B IgG or IgM?
What blod type are screening cells?
What reagent detects complement in vivo?
Polyspecific AHG
How can a typing discrepancy due to a cold antibody be resolved?
Warm to 37 C and repeat
Which antibody is associated with malaria?
Which antibody is the most antigenic?
Anti D
Which is the second most antigenic?
Which antigen diminishes during pregnancy?
What is used to resolve multiple antibodies?
Papain/ficin, reaction strengths and reactions temperature
If a previous antibody is now negative for the antibody, what type of blood should be given?
Antigen negative
When should polyagglutination be considered?
A + antibody reaction using monoclonal/polycolonal antisera
What might cause variation in reaction strength in the antibody screen?
Dosage, multiple antibodies, poor technique
Which blood group can build Anti H?
A1B more likely
Polyspeckific AHG detects which complement component?
C3b, C2d
How can a rare antibody that is not on the screen or panel be detected?
Incompativle crossmatch of unit; if unit is positive for antigen
Who must have a Du performed if the D is negative?
Blood donor
What if an allo reacts at RT, not at 37C, but again at AHG?
Complement binding IgM is present
How can the above problem be corrected?
Incubate at 37 C using IgG AHG (mono specific)
Write fisher race for R1R1 and r'R1
R1R1 = DCe/DCe
r'R1 = dCe/DCe
What is the ethnic background of some one who has Lewis a, b and duffy A antibodies?
Anti I reacts with which cells?
O cells, A2 cells, pt cells
Does not react with cord cells
Which antibody can cause hemolysis in IAT at RT?
Lewis a
What is an example of a phenotype?
What antibodies are destroyed when ficin is used?
M, N, S & Duffy
An antibody showing dosage may have a variation in reaction strength by how much?
What are symptoms commonly displayed by donors?
Dizziness, nausea, sweating - vasovagal symptoms
Must FFP be type and Rh specific?
Yes for ABO; Rh is not a contributing factor
What is the safest blood to give?
What lab results are important in determining component therapy in a massive transfusion?
PT, PTT, and platelet count
Why is the minor cross match no longer performed?
Whole blood is not given
If the recipient's IAT isnegative but the donor's DAT is +, how will this affect a crossmatch?
Will cause an incompatible crossmatch
When calculation the frequencies, the Rh percentage is not usually given. Do you know the percentage for Rh?
85% Postive
15% negative
If you receive a specimen on a patient that is 5 days old, accept or reject?
Accept or reject a hemolyzed specimen?
Reject - complement has been activated
What is the per purpose of the elution?
Removes antibody from the RBC membrane
How can dosage be determined on a panel?
Stronger reaction with homozygous cells
Which antibodies are naturally occurring?
How do you verify an antibody?
Perform a cell phenotype
Check to see if the ABY indicated by the panel reacts with the cell phenotype of antigen; If anti K is indicated by the panel, phnotype with K+ cells reacts? then K ABY
Could some one who delivered a baby 4 weeks ago donate today?
No 6 weeks
If some one weighs 105 pounds can they donate?
Defer today
Does ficin destroy Kell?
No, has no effect
What blood should be given to a recipient?
Type specific that is antigen negative
How many platelets does 1 unit of platelet concentrate contain?
55 x 10^9 make sure you look at units
Does FFP contain platelets
No only coagulation factors
What causes cell lysis?
Should a patient who had a previous antibody that is now negative for that antibody, be given antigen negative blood?
Will the major crossmatch verify donor ABO compatibility?
Yes, generally
When should leukocyte-reduced RBCs be given?
History of febrile
What type of FFP should be given to a Group O= person?
ABO compatible so O
What does irradiation do to a unit?
Inactivates the donor lymphocytes
When should FFP be given?
Coagulation factor deficiencies
What should be given to someone with iron deficiency anemia?
Packed RBCs
What is the best way to prevent CMV infections in immunocopromised pt?
Filter the WBC
If a decreased platelet count does not increase following a platelet transfusion, what should be done?
use a single donor or HLA matched platelets
Can donors who have aphaeresis give blood more frequently?
How quicly must a unit be used after the unit has been entered?
2 hours
Can a blood transfusion be hooked up to an existing IV?
What may thalassemia patient be given to reduce the number of transfusion?
Erythropoietin to increase reticulocytes (neocytes) production
What component is removed after a gentle centrifugation?
What type of blood should be given to a 25 year old female who is B= and you have no B units?
Would a pt who is refractory to random platelets benefit from irradiated blood products?
What are the symptoms for an intravascular hemolytic reaction?
Shock, renal failure, death
Also: DIC, Fever, chills, anxiety
Hemoglobinemia and Hemoglobinuria
If someone has received RHIgG, what will be the titer?
Low, less than 1:32 (often 1:8)
Which AHG is used in a baby DAT?
Polyspecific AHG
If a warm auto is present, how is it detected?
Auto + at AHG stage
If donor has + DAT, what happens in the crossmatch?
Incompatibility in AHG stage
What does "look-back" mean?
When donor finds out they are infected with HIV after giving blood. A letter is sent to recipient who has received the blood.
If a unit is mistyped, how does this effect a crossmatch?
All reactions are positive
How is blood issued in an emergency situation?
Doctor must sign release form, give o= first; o+ if not a female of childb
What is the purpose of irradiation?
Immunocompromised Pt. GVHD
Will irradiated blood be helpful for platelets?
If I and K antibodies are present, what phenotype should be given and should other precaustions be made?
Give K= blood, prewarm prior to transfusing
What should be given if platelet count is normal, PT increased, PTT increased?
Is this an example of HDN: the baby is Rh+, DAT =, mom is Rh=, IAT =?
Could some one who is healthy, hct of 38% give for an autologous donation?
Can platelets be contaminated by bacteria?
Which hepatitis can be contracted from a transfusion?
B & C
Can HIV be transmitted by pooled cryo?
Can HIV be transmitted in pooled products?
What amount of blood loss can occur and the pt still feel well?
500 mL
During acute blood loss, is blood directed to the extremities?
What adverse reaction is experienced during aphaeresis that is unique to aphaeresis?
citrate toxicity
What blood type should be given if the blood type changed after a bone marrow transplant?
Depends on the nature of the incompatibility and DAT results
What are example of immune transfusion reactions?
Febrile and non hemolytic
What is an example of delayed adverse reaction?
In bone marrow transplant, is HLA or ABO of great importance?
What are the consequences of DHTR?
Decreased hct, increased bilirubin
Has the p24 antigen test eliminated the window period?
Should a mom who is D= Du+ receive RhIgG?
If a pt is experiencing platelet refractory problems, will irradiating the unit be required?
When would you not want to salvage blood?
Cancer such as tumor removal
How much will random platelets increase the platelet count
5,000 to 10,000 platelets/unit
Febrile Reaction
Leukodepleted produces are used
Allergic reaction
IgA deficient recipient reacts to donor's blood; Rash and hives, use antihistamines
Intravascular hemolysis?
Several units of group A is given to group O person, Most serious reaction, may occur without prior exposure, associated with renal failure
Extravascular hemolysis?
Associated with IgG antibodies
Reaction occurs seven days after transfusion.