detection of foreign antibodies

Question 1

immune alloantibodies

Answer 1

formed as a response to exposure to foreign (non-ABO) RBC antigens

Question 2

naturally occuring alloantibodies

Answer 2

formed without exposure to RBC antigens

Question 3

passively acquired antibodies

Answer 3

antibodies produced in one person and transmitted to another via PLASMA containing blood products or IV immunoglobulin( IVIG) or rhogam

Question 4

autoantibodies

Answer 4

directed against RBC antigen on patient’s own cells; normally universal reactivity (ex. anti-U, anti-I)

Question 5

clinically sig antibodies

Answer 5

antibodies that decrease survival of RBC’s that possess the target antigen

Question 6

ONLY about 1% of the population of recipients has a detectable

Answer 6

RBC alloantibody (why we only screen)

Question 7

85% of D-negative patients develop

Answer 7

anti-D when exposed to D antigen

Question 8

all other antibodies develop in ______ or less of antigen-negative patients when exposed to that antigen

Answer 8

3%

Question 9

2 populations that need to be screened for unexpected antibodies

Answer 9

donors of allogenic units and patients scheduled to receive a transfusion

Question 10

WHEN possible who else should receive a screen

Answer 10

OB patients and transplant patients

Question 11

testing when there is an antibody present MUST include what phase

Answer 11

AHG

Question 12

IAT is enhance with

Answer 12

LISS or PEG

Question 13

enhancement media lowers _____ ________ around the cells allowing IgG to crosslink and form agglutinate

Answer 13

zeta potential

Question 14

If you use LISS there is an additional step

Answer 14

read after 37 incubation which can reveal IgG and IgM

Question 15

what is used to screen transfusion patients

Answer 15

2 or 3 cell panel

Question 16

RBC’s are also type ___ to avoid interference with ABO antibodies

Answer 16

O

Question 17

gel cards

Answer 17

used to reduce steps and tech error

Question 18

in gel cards cells move through ______ and if the antibody bound is it gets stuck in gel; unbound (negative) cells move to bottom

Answer 18

IgG

Question 19

solid phase testing (echo)

Answer 19

RBC antigens fixed to wells, 37 incubation with LISS allow binding of patient antibody to antigen on the well surface

Question 20

solid phase and gel testing reactivity looks opposite of what testing

Answer 20

tube testing

Question 21

low titer antibodies can be missed especially if they show

Answer 21

dosage

Question 22

about 25% of antibodies

Answer 22

drop below detectable limit within 7 months (this is why it’s important to put in patient history)

Question 23

info you may want if ID difficult

Answer 23

transfusion history/ preg, major diagnosis, current medications, demographic, previous blood bank history

Question 24

useful testing in hard cases

Answer 24

autocontrol results, DAT results, tube testing

Question 25

varying reaction strengths can point to

Answer 25

multiple antibodies or dosage or both

Question 26

positive reactions at multiple phase can suggest

Answer 26

multiple antibodies or unusual antibodies

Question 27

to confirm a antibody use

Answer 27

3 pos/ 3 neg rule

Question 28

where to start with difficult antibody ID

Answer 28

run more cells

Question 29

if there are multiple antibodies present you need to select cells that are

Answer 29

positive for antigen you want and negative for antigen that will call interference

Question 30

groups showing dosage

Answer 30

duffy, Rh, Kidd, MNS (duffy the kidd monkey loves M and N's)

Question 31

if your autocontrol is negative

Answer 31

you probably have multiple alloantibodies

Question 32

you can use a negative autocontrol as a

Answer 32

rule out cell

Question 33

enzymes that alter reactivity of RBC antigens

Answer 33

papin, bromelin, ficin, and trypsin

Question 34

groups enhances by enzymes

Answer 34

Rh, Kidd, Lewis, I, P

Question 35

groups destroyed by enzymes

Answer 35

duffy, MN, Ss, Xg

Question 36

DTT can be used with either

Answer 36

plasma or cells

Question 37

DTT breaks

Answer 37

disulfide bonds

Question 38

plasma treated with DTT has

Answer 38

IgM inactivated

Question 39

ZZAP =

Answer 39

DTT + papain

Question 40

ZZAP destroys

Answer 40

KELL

Question 41

ZZAP enhances

Answer 41

P1 and P

Question 42

adsorption

Answer 42

use patient's red cells with known antigenicity to remove one antibody from the plasma and use remainder to ID underlying antibodies

Question 43

autoadsorption

Answer 43

wash patient's cells, elute present antibody, incubate with plasma (lose reactivity with plasma because autoantibody adsorbed) and plasma can be used for other alloantibodies

Question 44

homologous adsorption

Answer 44

patient has low RBC count, they are antigen typed and then a closely matched cell can be used to absorb antibody from plasma

Question 45

differential adsorption

Answer 45

absorbs certain antibodies with a known cell and test plasma for any remaining antibodies; choose a cell that has the antigen you want to eliminate and lacks antigen you suspect

Question 46

differential adsorption will absorb every

Answer 46

positive antibody

Question 47

cold panel

Answer 47

run antibody screen AND autocontrol by adding 3 drops of patient plasma to cells and incubate for 15 min in fridge (cold antibody will be shown here )

Question 48

prewarm

Answer 48

the screen and any ID going to be run using plasma and cells that have been warmed to 37 degrees and washed with 37 degrees saline (removed interference from cold antibody)

Question 49

neutralization uses

Answer 49

NON RBC substances

Question 50

saliva from a secretor will have lewis and ABH antigens

Answer 50

useful for rare ABO subtypes

Question 51

breast milk contains

Answer 51

I antigen

Question 52

hydatid cyst fluid, pigeon droppings, and turtle dove egg white

Answer 52

neutralize anti-P

Question 53

if you lose reactivity on the enzyme-treated panel

Answer 53

suspect an antibody against an antigen that is destroyed by enzymes

Question 54

if control is positive

Answer 54

invalid

Question 55

darathumb immunotherapy

Answer 55

monoclonal IgG1k that binds CD38

Question 56

CD38 is

Answer 56

overexpressed on myeloma plasma cells

Question 57

CD38 is destroyed by

Answer 57

ZZAP (will allow other alloantibodies to be seen) (genetic testing is better)

Question 58

if you use ZZAP make sure the patient receives

Answer 58

Kell- negative units