Antibody Screen/Antibody ID/Crossmatch

Question 1

IgG antibodies detection

Answer 1

Antibodies with LISS/albumin or PEG potentiator shows reactivity usually in AHG phase

Question 2

IgM (cold) antibody detection

Answer 2

Antibodies usually show reactivity in the IS phase

Question 3

IgM broad thermal range

Answer 3

Antibodies show reactivity in IS and 37 degree C

Question 4

Purpose of patient autocontrol

Answer 4

To see if the patient has an antibody that will attach to their own cells, which also might interfere with the alloantibody search

Question 5

Purpose of antibody screen

Answer 5

To screen for the presence of unexpected antibodies that are not A, B or A,B

Question 6

IgG antibodies detected at AHG phase using LISS as a potentiator

Answer 6

Rh system, Kell, Duffy, Kidd, Ss

Question 7

IgM antibodies detected at IS phase only

Answer 7

M, N, P, Lewis

Question 8

Antibodies that are most likely cold agglutinins

Answer 8

M, N, P, Lewis, H, I, IH

Question 9

Advantage of using PEG over LISS/albumin as a potentiator

Answer 9

Enhances strength of reactions

Question 10

If a patient had a broad thermal range IgM antibody, where would the reactions take place in the antibody screen if LISS was used as the potentiator and you used anti-IgG AHG?

Answer 10

IS and 37

Question 11

If compliment has been activated, what evidence of this would you see in your test tube?

Answer 11

Agglutination with polyspecific AHG

May show hemolysis if serum is used and compliment continued to completion

Question 12

Why is it important to know if you have polyspecific AHG of monospecific AGH?

Answer 12

If compliment is involved or not

Question 13

What are antibody screen cells?

Answer 13

Type O RBC’s with a wide variety of common antigens

Question 14

Different probability for meeting 95% predictability

Answer 14

3 pos, 3 neg
2 pos, 5 neg
1 pos, 19 neg

Question 15

How does dosage appear in the reaction phase of an antibody ID panel?

Answer 15

Whenever the corresponding antigen (to patients unexpected antibody) is expressed homozygously, a stronger strength of agglutination is frequently apparent in contrast to the cell lines when the antigen is only expressed heterozygously

Question 16

How can you determine if the patient has an unexpected broad thermal range IgM antibody when you are doing get testing?

Answer 16

May miss it because AHG would be anti-IgG, you might catch it if the crossmatch tube is not compatible at IS phase.

Question 17

If the check cells don’t show agglutination in an unexpected antibody screen, what might have gone wrong?

Answer 17

Too much saline left from washing
Poor washing & unattached antibodies are bound the the free AHG so not available to attach to the check cells
Forgot the AHG reagent

Question 18

Which antigen/antibody reactions are decreased using enzymes?

Answer 18

Fya, Fyb, MNSs

Question 19

Which antigen/antibody reactions are increased using enzymes?

Answer 19

D, c, E, e, Jka, Jkb, Lea, Leb, P1, P

Question 20

Which antigen/antibody reactions don’t show dosage?

Answer 20

D, Lea, Leb, P1 and P

Question 21

Where are the antigen and antibody from in the autocontrol?

Answer 21

Antigen- patient RBCs

Antibody - patient serum/plasma

Question 22

Why do you do an autocontrol?

Answer 22

To make sure that an unexpected antibody is not an autoantibody

Question 23

Where is the antigen from and the antibody from in a crossmatch tube?

Answer 23

Antigen - donor RBCs

Antibody - patient serum/plasma

Question 24

If you need 2 units of packed cells for your patient that has an unexpected antibody - what formula do you use?

Answer 24

2 divided by the % of donor population without the antigen