Basic Antibody Identification

Question 1

What are the types of antibodies to be identified?

Answer 1

Expected - ABO, unexpected - all others

Immune stimulated v. naturally occurring

Passively acquired - IVIG, RHIG, ABO (through plasma transfusion)

Question 2

What are the four steps of antibody identification process

Answer 2

1. Antibody detection - positive IAT
2. Antibody identification - panels, patient ag typing
3. Determine clinically significance - IgG vs IgM
4. Appropriate transfusion considerations are put into place - Ag negative blood

Question 3

What are 5 uncommon antigens that are not required to be ruled out?

Answer 3

V, Cw, Kpa, Jsa, Lua

Question 4

Explain how albumin, LISS, PEG enhance reactions in IAT

Answer 4

albumin - disperses charges around cells and decrease the Zeta potential - 30-60’ incubation time

LISS - decreases Zeta potential and increases sensitization - 10-30’ incubation

PEG - removes water to concentrate Ab - 15-30’ incubation but cannot spin at 37C phase

Question 5

How do DTT & 2ME aid IAT?

Answer 5

disrupts the disulfide bonds of IgMs when added to serum

destroys kell and lutheran Ag (some HTLA) when incubated

Question 6

What are the AABB requirements for IAT?

Answer 6

37C incubation and use of AHG

for pretransfusion testing, prenatal testing (HDN and RHIG candidacy), and donor blood

Question 7

Explain the use of an AC tube

Answer 7

contains patient cells, patient plasma, and any enhancements/ media used with the other tubes.

used to test for autoagglutination or autoantibodies

should be negative and be the same result as Rh control and DAT

Question 8

How do you identify an antibody with 95% certainty?

Answer 8

have 3 Ag positive cells that react positively
have 3 Ag negative cells that react negatively
exclude all other common alloantibodies (prove that they are not present)
Prove that the patient is capable of making the antibody

Question 9

What are three antigen exceptions to the homozygous rule outs?

Answer 9

K, D, P

Question 10

Determine the clinical significance of an antibody based on blood group characteristics and serological results

Answer 10

IgGs are always clinically significant while IgMs are only significant if reacting at the coombs phase. Okay to give AHG crossmatch compatible blood