DAT
Name the 3 situations in which a person would have a positive DAT
HDN
Hemolytic Transfusion reaction
Autoimmune hemolytic anemia
What component is most frequently involved in transfusion related sepsis
Platelets
looking at antibody panel #1 what is the most likely antibody present?
anti-E
A recently transfused patient's serum has a positive antibody screen. The panel performed at IS, LISS, and 37 is showing strong anti-Fya and weak possible anti-C. To confirm the anti-C you would preform which ?
Elution
Absorption
Antigen typing
Enzyme Panel
Enzyme panel...it would destroy the Fya and increase reactivity with C
a patient has a Hgb of 8.1 g/dl . The surgeon wants the Hgb to be above 10 in order to perform surgery. How many RBC units need to be given to this patient ?
polyspecific AHG reagent contains
anti-IgG and anti-C3d
a patient is Type AB Negative : What type of Red cells can this patient receive and what type of plasma can this person receive
Red Cells : O, A, B , AB
Plasma : AB
a weakly reactive antibody with a titer of 128 is neutralized by plasma. What could this antibody be?
chidos (anti-Ch)
Rodgers (anti-Rg)
or other HTLA ( high titer low avidity antibodies )
autodsorption procedures to remove either warm or cold autoantibodies should not be used with a recently transfused patient. What does "recently " mean?
3 months
When using a high protein anti-D reagent the following results were obtained at AHG
Patient cells + anti-D = 2+
Patient cells + Rh control = 2+
How would you interpret this patients Rh typing ?
Invalid
**when using high protein anti-D a control should be performed .. this control lacks the anti-D and is expected to give a negative result. If you get a positive it invalidates the testing because it is saying the patient's cells are not necessarily reacting with the anti-D but could be reacting with the protein matrix of the reagent.
Polyethylene glycol ( PEG) enhances antigen-antibody reactions by
Concentrating the antibody and removing water
A suspected transfusion related death must be reported to :
FDA
An antibody- identification panel demonstrates possible anti-E and anti-K in a patient's serum. Which type of group O cell could be used to absorb the patient's serum and separate these antibodies so that anti-K remains in the absorbed serum?
E positive , K negative cell
A Kleihauer-Betke test indicates 10 fetal cells per 1,000 adult cells .For a woman with 5,000 ml blood volume , the proper dose of RhIG is ?
3
** 10/1000 = .01 *5000 /30 round and +1
describe the forward and reverse reactions seen in someone with Acquired B phenomenon
Forward - appears AB
reverse - appears A
** the incorrect result is the positive reaction on forward typing with anti-B.. this is due to usually colon cancer, infections or intestinal obstruction where patient gets an "acquired like B antigen"
The use of refrigerated , clotted blood specimens tend to result in a false ________ DAT
Positive
* due to in vitro complement attachment
A mother is group O Rh-Neg and has anti-K in her serum. Her baby is group B, Rh- positive and requires an exchange transfusion . Assuming that the exchange crossmatch is performed using the maternal serum what type of Red Blood cells should be given?
O Rh Negative K-Negative
A woman is diagnosed as having immune hemolytic anemia . Her direct antiglobulin test is positive but her indirect antiglobulin test in negative . Absorption-elution techniques are employed to identify the causative antibody . The eluate gives the following agglutination pattern with group O cells of the following genotypes :
cDE/cDE - Neg
cdE/cDE - Neg
cde/cde - 4+
cDE/cde - 2+
CDe/cDE - 2+
What is the likely antibody ?
anti-e
If a patient has anti-k and you want to see if they have any other underlying alloantibodies , what can you do to the cells to get rid of the anti-k ?
treat with ZZAP
**ZZAP - papain and DTT also destroys M,N , Duffy and all of K blood group
A patient with anti-K and anti-Jka needs 2 units of RBCs for surgery . How many group-specific units would need to be screened to find 2 units of RBCs?
Frequency of Jka positive = 77%
Frequency of K postive = 10%
10 units
need Jka neg, K neg so need .23 x .90 = 0.21
need 2 units so 2/0.21 = 9.5 round to 10
If using monospecific Antiglobulin reagent in a DAT what results would you expect for a patient with PCH using Anti-C3d only ? Using Anti-IgG only ?
Anti-IgG= Neg
The transfusion component of choice for a patient with a prolonged bleeding time, increased APTT , decreased level of factor VIII, and impaired aggregation of platelets in response to ristocetin would be?
Cryoprecipitate
** these results indicate Von Willebrand Disease.. both vWF and factor VIII are deficient and only Cryo can replace them both
Look at panel #2
Identify the most likely antibody(ies) present
Anti-K
Anti-Fyb
An elution method that can be used to detect non-ABO IgG antibodies is __________
Where as the best method for detecting ABO IgG antibodies is ___________
acid elution (pH)
Heat/Lui freeze thaw method
A patient whose blood is a subgroup of A has the following reactions when tested against various antisera:
Antisera Reaction with patient's RBC
Dolichos biflorus Negative
Anti-A mixed field
anti-A, B mixed field
which subgroup of A is this patient most likely ?
A3
*** A3 subgroup is characteristic of giving mixed field reactions with Anti-A and Anti-A,B