Special Tech

Question 1

Elution

Answer 1

• Remove Ab from RBC (destroy RBC)
• Only done with DAT positive only with IgG
• Result:
  + No Ab eluted: drug Ab, junk, bad DAT
  + Panagglutinin eluted: Warm Auto
  + Ab with specificity: anti-Jka, etc, or Delay transufion
• Wash more

Question 2

Elution method

Answer 2

• Temp: Lui freeze - thaw
• pH: Acid elution
• Organic chemical: Ether, Xylene, Chloroform

Question 3

Adsorption

Answer 3

• Remove warm autos or high incidence antibodies to find underneath reactivity
• Detect very weak expression of Ab
• Autoadsorption or Alloadsorption
• Adsorption and elution

Question 4

Autoadsorption

Answer 4

• Remove Ab on patient’s RBC
• Use RBC treated to soak up Ab in their plasma
• Pros: don’t worry about adsorption of high incidence Ab besides warm auto
• Cons: Not for transfused pt, use a lot of blood from hemolysis patient.

Question 5

Alloadsorption - F1 (phenotype pt)

Answer 5

• Look for similar donor’s RBC & perform adsorption
• Cells will be treated with enzymes (better soak up auto)
• Pros: good source of cells
• Cons: may adsorb out a high incidence

Question 6

Alloadsorption - F2 (No phenotype pt)

Answer 6

• Use a panel of donor cells & perform multiple adsorptions
• Pro: No phenotyping
• Cons: time consuming, complicated, adsorb out high incidence Ab

Question 7

Adsorption & Elution - Ael

Answer 7

• Marinated cells with Ab as long as possible
• Eluate
• Ab presents show there should be Ag
• More sensitive

Question 8

Titer

Answer 8

• How much Ab?
• Serial dilution
• Use dilution to test against antigen positive cells –> AHG
• Highly subjective
• Monitor pregnancy to see if Ab is stimulated
• Check if Ab is HTLA (high titer low avidity)

Question 9

Chemical

Answer 9

• DTT/2ME/AET: Thiol reagent, destroy Kell & High incidence, destroy IgM, helpful for Daratumumab pt
• Chloroquine: destroy Bg, destroy IgG bound on RBC
• EDTA Glycine-Acid (EGA): destroy Kell, destroy IgG bund on RBC

Question 10

Enzyme

Answer 10

• Papain, Ficin
• Destroy Duffy, MNSs
• Enhance Kell, Kidds
• Kell: intact

Question 11

Phenotyping

Answer 11

• Antigen typing: not for transfused pt
• If pt has transfusion: Hypotonic wash (0.3% saline will not destroy sickle cells), Reticulocyte separation, genotyping, call for history
• Positive DAT for IgG: EGA, chloroquine –> destroy IgG