1, 2. Antibody Investigation Flashcards Preview

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Flashcards in 1, 2. Antibody Investigation Deck (44):
1

Anti-I (big I) is __ with adult cells and __ with cord cells

POS with adult cells
NEG with cord cells

2

_____ antibodies are special kinds of high frequency antigens

HTLA (high titre, low avidity)

3

This antibody is RARE and sometimes associated w/ infectious mononucleosis

anti-i (small i)

4

This antibody determination procedure is NOT recommended if the patient recently received a transfusion

autoadsorption

5

Can cause cold hemagglutinin disease

auto-anti-I (big I)

6

What is ZZAP

papain/ficin + DTT

7

Purpose of ZZAP?

Used to get rid of autoantibodies

Sulfhydrl reagent removes IgM abs from cells, then the enzymes enhance uptake of autoantibody

8

These antibodies are suspected if the screen is negative and the crossmatch is positive

Antibodies under "routine exclusion usually not required" or low-freq

-Cw, -V, -Kp^a, -Js^a, -Lu^a, -Wr^a

9

Term meaning "weak reactions, even when undiluted (neat) plasma is used"

Low avidity

10

How to neutralize HLA antibodies?

Use human platelet concentrate (HPC) => platelets contains lots of HLA antigens => adsorption

11

This reagent enhances IgM antibodies

LISS

12

The purpose of additional procedures when working up a warm autoantibody?

Identify potential underlying alloantibodies

13

Antibodies in this system are sensitive to sulfhydryl reagents

Kell

14

Autoantibodies cause DAT to be almost always positive due to ____ and maybe ___

always - C3
maybe - IgG

15

Last resort when other options don't eliminate the cold autoantibody?

Adsorption at 4 degC

16

The presence of this disease will usually cause crossmatches to be all incompatible => give the least incompatible blood

WAIHA (warm autoimmune hemolytic anemia)

17

Traditionally called Bg antigens

Human leukocyte antigens (HLA)

18

How do you know if you have one of the "routine exclusion is not usually required" antibodies?

Screen is negative but crossmatch is positive

19

To avoid cold antibodies reactivity, why is anti-IgG used instead of polyspecific AHG reagent?

Anti-IgG doesn't detect attachment of complement (most cold antibodies are C3 positive)

20

Alternative to using patient's own cells for adsorption is the use of ________

RESt (rabbit erythrocyte stroma kit)

21

The procedure that removes intact antibodies from the red cell membranes is?

elution

22

Selected cells must be _________ for the antibody identified and __________ for the CRO

negative; positive

23

How to eliminate cold antibody reactivity?

Pre-warm technique

24

Term meaning "not easily diluted out, persistent"

High-titre

25

What is a cold panel and its purpose

Test patient plasma w/ adult AND cord cells

To detect anti-I (big I)

26

High freq antigens occur at a frequency of ___%

98%

27

Unless it's this disease, cold autoantibodies are usually not clinically significant

cold agglutinin

28

2 objectives in antibody investigation?

1. Identify the antibody(ies) that are present
- single Ab specificity
- multiple Ab resolution

2. Make sure no other antibodies are present

29

These 3 reagents enhance warm antibodies

LISS, PEG, enzymes

30

4 high frequency antibodies (>98%)

-k
-Kp^b
-Js^b
-Lu^b

31

How to tell if an antibody being ID'd is in the Kell system?

Initially positive for all cells tested, treat w/ sulfhydryl reagent, re-test => should all become negative

32

Patient history w/ pneumonia suggests which disease?

Cold autoimmune disease

33

Are HTLA antibodies usually clinically significant?

No, but they need to be removed to identify underlying alloantibodies

34

A very strong _________ can cause cold agglutinin disease

auto-anti-I

35

How to identify cold antibodies?

Incubate panel at RT or lower to enhance rxns

36

Possible reason for an entire panel being negative?

Low frequency antigen

37

3 key points of a typical reaction pattern when HTLA antibody present

- Weak rxns at the IAT phase
- Variable rxns among panel cells
- Inconsistent rxns that are sometimes NOT reproducible

38

Problem with HTLA antibodies even though they don't cause HDFN or transfusion rxns?

May mask clinically significant antibodies

39

The procedure that removes intact antibodies from the red cell membranes is?

autoadsorption

40

Patient history w/ lupus or carcinoma suggests which autoantibody?

Warm autoantibody

41

Significance of HLA antibodies?

Can mask other antibodies or interfere with testing

42

What type of antibody would be responsible for causing antigram to have almost all positive, same phase, same strength?

High-frequency antibody

43

These reagents denature IgM

sulfhydryl

44

Type of antibodies that can be adsorbed using RESt?

Cold autoantibodies