Blood Bank Makeup Exam Part 2 Flashcards
A patient has anti-P1 that reacts only with ficin treated cells. What should be done to find four units of compatible red blood cells?
Test donor cells with compared anti-P1 until 4 units are found; then crossmatched at 37 degrees to AHG
No crossmatching beyond the immediate spin phase is necessary; therefore, find four units of the patient’s ABO/Rh type. Any units found compatible at the immediate spin phase can be transfused
Crossmatch ABO/Rh compatible cells at 37 C degrees to AHG. Any that are compatible can be transfused
Neutralize the serum with hydatid cyst fluid and perform crossmatches at 37 degrees to AHG. Anything compatible can be transfused
Crossmatch ABO/Rh compatible cells at 37 C degrees to AHG. Any that are compatible can be transfused
Which two blood group systems are similar in that the antigens are highly antigenic and any antibodies against these antigens are clinically significant, yet finding compatible red blood cells lacking the antigens is not difficult?
P and I blood group systems
Rh and K blood group antigens
Kidd and Duffy blood group systems
Lutheran and Lewis blood group systems
Rh and K blood group antigens
What is the most likely explanation when screen cells, panel cells, the auto control and all crossmatches are positive at 37 degrees, but negative after the addition of antihuman globulin?
A warm autoantibody
A mixture of warm autoantibodies and alloantibodies
Rouleaux
An alloantibody to a high incidence antigen
Rouleaux
Why is anti-IgG needed to detect IgG sensitized cells?
The IgG molecule attracts more than one cell and anti-IgG creates a spatially accurate distance between cells
The IgG molecule coating cells cannot span the distance between sensitized cells; therefore, anti-IgG links the Fc portions of the bound IgG molecules so that a lattice is formed, and agglutination is detected
The anti-IgG is specific for the variable region of all IgG antibodies; therefore, it is the ideal antibody to detect any specificity
The anti-IgG molecule can span the distance between cells and can attach to the antigen on red blood cells, pulling them together and causing visualization of agglutination
The IgG molecule coating cells cannot span the distance between sensitized cells; therefore, anti-IgG links the Fc portions of the bound IgG molecules so that a lattice is formed, and agglutination is detected
A patient is suspected of having paroxysmal cold hemoglobinuria (PCH). Which pattern of reactivity is characteristic of the Donath-Landsteiner antibody, which causes this condition?
The antibody attaches to red blood cells at 4 C and causes hemolysis at 37 C
The antibody attaches to red cells at 37 C and causes agglutination at the IAT phase of testing
The antibody attaches to red cells at 22 C and causes hemolysis at 37C
The antibody attaches to red cells and causes agglutination at the IAT phase of testing
The antibody attaches to red blood cells at 4 C and causes hemolysis at 37 C
A positive reaction is seen at 37 degrees between the patient’s serum and ficin treated cells (including the autologous cells that are ficin treated) and negative results are obtained after adding antihuman globulin. Check cells were positive. What does this mean?
The patient has an alloantibody to a high frequency antigen since all the cells yielded reactions after 37 degrees
The patient has an autoantibody since the auto control was positive after 37 degrees
The patient has a ficin panagglutinin since all cells that were ficin treated reacted at 37 degrees
The patient has an alloantibody to a low frequency since all the cells were negative after adding antihuman globulin
The patient has a ficin panagglutinin since all cells that were ficin treated reacted at 37 degrees
In a serial dilution, you obtained positive results in your lower dilutions, positive in the middle ranges, and negative in the higher dilutions. What should you do?
Repeat the test
Report test as inconclusive
Report the titer of the highest dilution with a positive test
Report the titer of lowest dilution with a positive
Report the titer of the highest dilution with a positive test
If a patient has an antibody to anti-Kp(b), what is the challenge in finding compatible blood?
There is no challenge, Kp(b-) blood is readily available
Anti-Kp(b) is a “crossmatch compatible” antibody; therefore, the patient’s serum would be crossmatched against cells until a compatible unit is found
The Kp(b) antigen is a high frequency antigen; therefore, it would be difficult to find compatible red blood cells. Possibly siblings would be compatible
Anti-Kp(b) is a clinically insignificant antibody; so there would be no need to find red blood cells that are Kp(b-)
The Kp(b) antigen is a high frequency antigen; therefore, it would be difficult to find compatible red blood cells. Possibly siblings would be compatible
A patient has no history of a clinically significant antibody and the antibody screen using LISS enhancement at 37 C on to the antihuman globulin phase was negative. Check cells were positive. Which of the following crossmatch procedures is recommended?
Immediate spin, room temp major crossmatch
37 C LISS to antihuman globulin major crossmatch
Ficin related donor cells at 37 C to antihuman globulin
No crossmatch necessary
Immediate spin, room temp major crossmatch
In antibody detection procedures, a positive auto control after the addition of AHG is usually indicative of:
Inadequate washing
Positive DAT
Positive IAT
Rouleaux
Positive DAT
Why is rouleaux not found in the AHG phase of antibody screens?
High protein molecules are not reactive at 37 C
Patient cells are washed away before adding AHG
Patient serum is washed away before adding AHG
None of the above
Patient serum is washed away before adding AHG
An antibody screen and crossmatch for six units of red blood cells was performed. All units were 4+ incompatible at immediate spin, 3+ incompatible after adding antihuman globulin. The antibody screen was negative and there was no ABO discrepancy between the patient’s cells and serum. What is the most probable explanation for this?
The units of blood have been incorrectly ABO typed
The patient has an antibody to a high frequency antigen
The patient has an antibody to a low frequency antigen
The patients serum is not ABO compatible with the donor cells
The units of blood have been incorrectly ABO typed
What is the possible explanation for a nonreactive eluate?
Hemolytic disease of the newborn (HDN)
Positive DAT due to drugs
A warm autoantibody
All of the above
Positive DAT due to drugs
After the serum and cells were incubated for the appropriate time at 37 degrees, a tech washed the tubes by filling each tube one-third full of saline, centrifuging, decanting and repeating the procedure two additional times. AHG was added after a dry cell button was prepared. All results were negative; therefore check cells were added. All results were negative after the addition of the check cells. Choose the correct answer from below.
The results are most probably correct, and a “negative” result can be reported
The check cells are negative because the cells in the tubes were not properly washed.
Repeat the test exactly as done above but use a new bottle of check cells.
Add one more drop of check cells and re centrifuged
The check cells are negative because the cells in the tubes were not properly washed.
One drop of Coombs control cells was added to a negative antibody screen. No agglutination was observed after centrifugation. What course of action should be taken?
Report negative result
Report inconclusive result
Repeat the test
Add one more drop of check cells and re centrifuged
Repeat the test
A woman of childbearing age who was group AB negative was in need of whole blood. Since none was available, which of the following could be used?
Group AB positive whole blood
Group O negative packed cells
Group A negative whole blood
Group A positive packed cells
Group O negative packed cells
