Exam 4 Flashcards
Which blood group system is associated with resistance to malaria?
Duffy
Which antibodies are considered cold agglutinins?
- Anti-I
- Anti-M
- Anti-N
- Anti-P1
Which autoantibody specificity is associated with Paroxysmal Cold Hemoglobinuria and what test that was discussed in lecture is used to detect it?
- Auto Anit-P
- Donath-Landsteiner Test
Which antigens are destroyed by enzymes and which are enhanced by enzymes?
Destroyed:
-M, N, S, Fya, Fyb
Enhanced:
- I, Jka,jkb i, P1, Rh, Lewis (LIPKiR) (no D)
What procedure might help you distinguish between an anti-Fyᵃ and an anti-Jkᵃ?
Ficin-treated panel. It cuts down/destroys Fya and enhances Jka.
Which blood group is produced in the tissues?
Lewis
What is the McLeod phenotype?
Absence of Kx antigens
Which of the antibodies from the other blood group systems discussed for this exam require the antiglobulin test (AHG) for in vitro detection?
- S
- s
- M (all phases)
- N (all phases)
- LuB
- Kell
- Duffy
- Kidd
What is the rarest phenotype of the Lutheran system?
Lu (a- b-)
Which antigen is X-linked?
Xga
Which antibody is often found in patients with infectious mono, lymphoproliferative disease, and cold agglutinins?
Anti-i
Which antibodies are known for causing delayed HTR?
Kidd
Fy(a-b-) is found primarily in what type of population?
Black (68% frequency)
Which antigen is found primarily in South Central and North American Indians and Asians?
Dia
Which blood group systems are known for showing dosage?
- M
- N
- S
- Kidd
- Duffy
- Rh (other than D)
What is the most common antibody seen in the BB besides ABO and Rh antibodies?
Anti-K
Which blood group antigen increases in strength as a newborn grows older?
I
Can a patient with blood group Ss be immunized by genotype SS, Ss, or ss?
No
Which antigens are actually WBC antigens that are expressed in variable degrees on red blood cells and can cause confusing reactions in serological test?
Bg
Which antigens are well-developed at birth, susceptible to enzymes, and generally saline reactive?
- M
- N
Name 3 most common antibodies that most likely to react at 37◦C?
- Anti-D
- Anti-E
- Anti-K
What is the most practical manner for preventing transmission of malaria by blood transfusion?
Don’t accept blood from people that have lived in or recently traveled from a high malarial incidence area.
List the reasons a prospective donor might be permanently rejected for donation of blood products
- AIDS
- Hepatitis
- HTLV
- IV drug user
- M/M sex since 1977, even once
- “Do not use” sticker
- Relative with Creutzfeldt-Jakob Disease (CJD)
- Chagas disease
- MS
- Myocardial infarction
- Stroke
List the reasons a prospective donor might be temporarily deferred and for how long.
- Tattoo/piercing - 1 year
- Antibiotics - until course is completed
- Aspirin - 3 days
- Low Hct - next visit
- STD - 12 months following Dx
- Transfusion - 1 year
- Slept with prostitute - 1 year
- Recent vaccines - 4 to 6 weeks
Can unused autologous be placed in the general supply and used for another patient other than who it was intended?
No. It was not screened by the usual procedures.
Explain the difference between plasmapheresis, cytapheresis, and plateletpheresis
- Plasmapheresis: plasma
- Cytapheresis: cells
- Platletpheresis: platelets
Explain the significance of why donor units should be tested for a weak D antigen.
Rh+ should not be given to Rh- patients
What are the two terms used to refer to AHG that contains both anti-complement and anti-IgG?
Polyspecific
Broad spectrum
A transfusion that replaces approximately a patient’s blood volume within a 24 hour period is called what kind of transfusion?
Massive
When a physician signs an order for uncrossmatched blood and accepts full responsibility for the transfusion of such products, this is referred to as _________________ ________________?
Emergency Release
Why are homozygous cells used for “ruling out”?
Shows dosage on some antibodies
Why should a patient’s serum/plasma for compatibility testing be stored?
If any concerns with original testing (e.g. transfusion rxn) can be retested
Leukocyte antibodies are usually responsible for what type of transfusion reaction?
Febrile reactions in people with multiple transfusions.
Which blood bank test detects in vitro sensitization?
IAT
Explain how the shelf life for blood is determined.
70 % Viability of RBCs after transfusion
What is the purpose of the albumin/LISS portion of an antibody screen or crossmatch?
Detect IgG (such as Rh antibodies)
A positive DAT would give you what kind of information on the patient?
In vivo RBC sensitization –> RBC coated with gamma or beta globulins
A patient that has had multiple transfusions is most likely to have what type of transfusion reaction?
Febrile
What does CPDA stand for?
CPDA = Citrate phosphate dextrose adenine
What is the shelf life of a unit of blood with CPDA-1 as the anticoagulant?
-CPDA-1 : 35 days
What is the shelf life of as unit with the additive AS-1 (3 or 5) ?
-AS-1 (3 or 5): 42 days
How often should a new recipient sample be collected if a series of transfusions are to be administered over a period of several days?
Every 3 days
Incomplete antibodies are usually Ig___?
IgG
What does it mean to perform a major crossmatch?
Recipient plasma / donor cells
Cells are “washed” how many times in an antibody screen? What is the purpose of doing this?
3 times. This prevents neutralization of AHG from globulins in blood sample.
What is therapeutic phlebotomy and why is it used? Give two diseases or conditions in which this might be used.
- Bloodletting.
- Polycethemia vera,
- Hemachromatosis
- Porphyias
What type of transfusion is it when a recipient serves as his/her own donor?
Autologous
What is the “three in, three out” rule? Why is this used?
When doing an antibody panel, and you suspect a specific antibody, pick 3 bottles of cells that are positive for the antigen, 3 bottles that are negative. Test against plasma. Will confirm antibody.
Explain an antibody screen: why and when is it done, what are the stages of the screen, what happens if it is positive, and why is there a control?
This is done to detect clinically significant antibodies prior to transfusing. Screen is 2-3 bottles (any antibodies).
Stages: IS, AHG,37Deg
Panel follows to confirm ID of specific antibody. If there is a positive control, there is in vivo sensitization. Any negative tubes will have to be checked to check cells.
Explain TRALI. tranfusion related acute lung injury
Transfusion Related Lung Injury
Transfusion complication. Acute onset of pulmonary edema after receiving blood products. Caused by reaction to leukocyte antibodies in plasma that causes plasma leakage into lungs –> could result in pulmonary edema, the leading cause of transfusion-related deaths.
What is a directed or specific donation?
Donated blood intended for a specific recipient.
What antibodies Correlate Anti-Dia
Diego
What antibodies Correlate Anti-Sc2
Scianna
What antibodies Correlate Anti-Xga
XG
What antibodies Correlate Anti-Cob
Colton
What antibodies Correlate Anti-Ch3
Chido/Rogers
What antibodies Correlate Anti-Ge3
Gerbich
If you do an antibody panel and all cells are positive, including the control, what should be the first thing you should think of may be causing the problem?
Warm or cold auto-antibody
What is the preferred storage temperature for RBC’s
1-6C
