BB Test #4

What additional test do you do on mom if the fetal screen is positive?

Weak D

How long do you have post partum to administer rhogam?

72 hrs

What assumption should be made if the baby sample cannot be provided?

Assume baby is Rh pos

RBC characteristics for intrauterine Tx

-High Hct

- Fresh

- IRRD

- CMV neg/Leuko reduced

- HgbS neg

-O neg

- Ag neg

- compatible with mom

How do you sample to test fetal antigen status?

collection via percutaneous, amniocentesis, or chorionic villus sampling

What is the purpose of titers?

- monitor HDFN

- characterize HTLA (using homozygous cells)

When do you perform an eluate?

When DAT is positive (IgG)

When do you do an enzyme/chemical treatment?

Need to rule when multiple high frequency antigens are present; ABO discrepancies

What is the purpose of neutralization?

confirm an antibody

When would you do a saline replacement?

when there is rouleaux

What cells are ran in a Short Cold panel?

A1 (2 lots)

A2 (2 lots)

B (2 lots)

SC I and II

cord

auto

What antigens do enzymes destroy?

Duffy

MN sometimes S

What antigens are enhanced by enzymes?

Rh, ABO, I, Le, P, Kidd

How do ficin and papain work?

cleave polypeptides containing sialic acid molecules

What antigens do chemicals destroy?

Kell

Lutheran

LW

What are the common chemicals used that destroy disulfide bonds?

AET

Chloroquin

DTT

2-ME

What is included in ZZAP/WARM?

DTT and proteolytic enzyme

What does ZZAP destroy?

Duffy

MN sometimes S

Lutheran

Kell

LW

*everything that enzymes and chemicals destroy

What neutralizes anti-Lea and Leb?

human saliva

What neutralizes anti-P or P1

pigeon egg whites

or liver flukes

What neutralizes anti-Sda?

human urine

What neutralizes Ch/Rg?

human plasma

When do you do a DAT?

cord samples

positive auto

incompatible AHG XM

What demographic is associated with Duffy null?

African

*resistant to Plasmodium vivax

What demographic is associated with Jk null?

Polynesians/ Pacific Islanders

When would you perform an autologous adsorption?

the patient has not been transfused in the past 3 months and you have enough sample

When would you perform an allogenic adsorption?

-patient has been trasnfused in past 3 months

- pt has not been transfused/you have limited sample

- pt has not been transfused/you have clot tube

An Oneg pt with neg ABSC just had an Apos baby with pos DAT. The positive DAT is presumably due to?

A. Maternal anti-A and/or Anti-A,B

B. Maternal anti-B

C. Maternal anti-D

D. Maternal anti-K

A. maternal anti-A or -A,B

The Oneg mom with Apos baby has a positive Fetal Blood Screen. Which tests could be used to determine the volume of fetal maternal bleed?

A. Fetal F flow cytometry

B. Kleihauer Betke

C. Fetal F quantitative

D. D antibody titer

A and B

Fetal flow and KB are quantitative tests

If the Oneg mom with Apos baby had a 3% bleed, how many doses of RhIg should she get?

A. 3

B. 5

C. 2

D. 6

D. 6

[(0.03*5000mL) /30mL] + 1 dose

All the following are characteristics of ABO HDFN except:

A. the Ab is IgM

B. the mother is group O

C. the mother has anti-A, -B, -A,B

D. the infant has mild HDN

A. the Ab is IgM

*IgM does not cross the placenta

If the baby's anti-D in indeterminate (weak D pos, w/ pos control) and DAT is positive, what is the next step to determine if a fetal bleed occured?

Kleihauer Betke

*you can't do Fetal Screen if baby is weak D positive b/c it is not sensitive enough

If the fetal screen is positive, what is the next step to perform on mom?

Weak D

T/F: The baby's Rh is invalid due to the positive DAT

False

DAT would affect weak D test which was not needed on this baby

What blood bank tool can cleave polypeptides containing sialic acid molecules from polysaccharide chains?

Ficin

Papain

Trypsin

Which option is the best example of when to enhance?

A. ABSC was neg

B. weak reacting Ab w/ no particular pattern

C. every cell on the panel is reacting from IS-AHG

D. weak reacting Ab looking like an anti-c

D. weak reacting Ab looking like an anti-c

All the following can cause a positive DAT except?

A. HDFN

B. WAA

C. Delayed hemolytic Tx Rxn

D. being weak subgroup of A

D. being a weak subgroup of A

An elution can be used for which of the following? (multiple answers correct)

A. Assist in identifying weak subgroup of A

B. assist in clarification of compound antibodies like anti-G

C. determining the approximate quant. of antibodies present

D. separating multiple antibodies

A, B and D

Which blood group can withstand Lui Freeze Thaw or 56C heat elution?

A. Jk

B. ABO

C. Rh

D. Fy

B. ABO

What is the purpose of testing the last wash in an elution?

Make sure there is no free antibodies in the test system

Patient X has a positive ABSC, a panreactive ABID panel with a reactive auto-control, DAT is positive with IgG, and the eluate is reactive with all cells ran. The patient has not been transfused in the past 3 months but is a difficult draw. You will not be getting any more sample. Patient has a Hgb of 6.5 g/dL. What test do you perform next?

A. autologous adsorption

B. titration

C. allogenic adsorption

D. Lui Freeze Thaw Elution

C. allogenic adsorption