Blood Bank Exam 1: Rh Blood Group System Serologic Weak D and IAT

AHG stands for

anti human globulin

when do we test AHG

when immediate spin Anti D is negative or weak

incubate at 37

wash 4 times

add AHG and anti IgG/IgM

Weak D is

negative on direct agglutination but can be detected with IAT

IgM is this shape

pentamer

IgG is this shape

monomer

most commonly used antiglobulin reagent

monospecific Anti IgG

procedure for weak D

1 drop Pt RBC

1 drop Anti D

wask 4 times

add AHG

spin and look for agglutination

check cells are used when

we have a negative weak D test

check cells should be

positive

what are check cells

RBCs coated with IgG

why is washing important

excess antibodies can cause a false negative result

when check cells are negative it means this

the test is invalid

serologic weak D definition

identified by a weak reactivity or by discordant typing results

are RHD genes diverse?

yes >700 alleles have been reported

weakened expression of D can be caused by

C in trans with RHD

weak D is usually caused by

a single change in an amino acid

weak partial D can be interpreted as RhD

positive or negative

normal RhD all pieces are

present

in weak D type 1 there are _______ pieced present

fewer

Type 1 weak D allele name

RHD*01W.01

Type 2 weak D allele name

RHD*01W.02

Type 3 weak D allele name

RHD*01W.03

Type 4 weak D

RHD*09.01

weak partial D allele name

RHD*09.03

weak D is a poor

immunogen

Anti-D can destroy this kind of RBC

D positive

why is Anti-A,B used in blood bank

to confirm that a type O is truly a type O

why is Anti-D used

do double check that someone is O negative

forward typing

if someone is only weak D positive, would we say they are O pos or O neg

O pos

when do we perform weak D testing

blood donors

infacts of Rh negative mom to determine if the mom should be given RhIG

when is it not needed to test weak D

pre transfusion

prenatal patients

what is the source of polyclonal antibodies

human source

Anti-A and Anti-B is made of

carbs

Anti-D is made of

protein

reasons why we might have RhD typing discrepancies

Variation in RhD antigen expression

reagent differences

issue with the method of testing

why someone is being typed

f antigen is only found when we have

c and e

Anti-G reactivity

D+ C+ G+

3+

Anti-G reactivity

C+ G+

3+

Anti-G reactivity

D+ G+

3+

Anti-G reactivity

D- C- G-

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