Week 4

Question 1

what is tested with specific antisera

Answer 1

Rh antigens (C, E, c, e) and Other Blood Group

Question 2

What is included in a Type and Screen.

Answer 2

Testing for A, B, and D antigens on patient red cells

Question 3

When would we perform phenotyping

Answer 3

-If antibodies are detected in the patient’s plasma, we must prove that the patient lacks the antigen on the red cells (alloantibodies).
-Testing donor units to give multi-transfused patients antigen-negative blood to prevent antibody production (Sickle cell and Thalassemia patients).
-manufacturer types donors to create screening panel cells
-paternity testing
-only phenotype is pt has NOT been transfused in last 3 months (doesnt include ABO/rh)
-* Testing donor units for an antigen if the patient has developed an antibody and requires transfusions.
* Test donor units if the patient has a history of an antibody (previously identified antibody).

Question 4

Antisera
Produced from:

Answer 4

Pools of serum from immunized individuals
\
Monoclonal antibodies from hybridomas

they dont always react the same as ABs in HUMAN serum/plasma

Question 5

types of antisera

Answer 5

-antisera can be manipulated
Monoclonal IgM or Polyclonal Mixture of IgG and IgM
-Anti-D1 and Anti-D2
-*IS IgM versions of Anti-K, Anti-S, and Anti-Jka (antiserum) all exist even though pt would develop IgG

*ABBAPHILeMiN – IgM antibodies (in serum/plasma)

*Duffy’S Kidds R OK – IgG antibodies (in serum/plasma)

Question 6

Variables in testing could include:

Answer 6

-Human source serum vs. monoclonal
-* I.S , IAT , and MTS methods
* Different proportions: 1 drop 5% red cells + 2 drops antisera
-* Different incubation times (incubation period varies with methods)
-some dont need centrifugation and sit at RT for 15 mins and resuspend while some techniques need a washing step

Question 7

Antisera
ABO & D typing QC

Answer 7

• Results/Grading is generally strong
• Typing performed on every patient
  *ABO ‘forward & reverse’ built-in QA
• Using Anti-D1 and Anti-D2 is a check

ABO & Rh QC is performed Daily on each antiserum rack in the Hospital or Lab setting.

Question 8

Antisera
Other Blood Group phenotyping: QC

Answer 8

• No reverse group (RA/RB) or second antisera (D1/D2) used
  *Antisera may not be tested for days or weeks
  -OBG antisera – must run positive & negative controls
  -use manufacturers cells for testing pos and neg since we know the phenotype of the cellls

C+c+ as positive for Anti-C
C-c+ as negative control for Anti-C

Question 9

Antiserum Quality Control
negative control has what
positive has what

Answer 9

Negative control:
Cells must LACK the antigen

Positive control:
Cells must demonstrate the antigen in the weakest form (heterozygous cells)
If the antiserum will detect the weakest form of the antigen, then it will detect the strongest form

Question 10

Positive Phenotyping Control

Answer 10

Antigens with no alleles or silent alleles
◦ Use any antigen-positive cell

Antigens with co-dominant alleles
◦ Must use heterozygous expression of antigen

Question 11

Phenotype does what

Answer 11

indicates which antigens are present (performed with serological testing).

Patient is Jka+ & Jkb- phenotyping or Jk(a+b-)
-they can be JkaJka genetically (genotype)

select the first possible cell whenever choosing cells for QC

Question 12

genotype does what

Answer 12

suggests which genes are present according to the presence of antigen

Patient is Fya- & Fyb+ phenotyping or Fy(a-b+)
they can be Fyb Fyb genetically (genotype)