Complex Antibody ID

Question 1

List abnormal results

Answer 1

• Mixed field panel
• Positive auto-control
• Non-pattern match
• Weak reactivity
• All cells are positive

Question 2

Fibrin can cause what results?

Answer 2

• False positive
• Mixed field on panel cells

Question 3

Dosage

Answer 3

• Ab reacts more strongly with homozygous Ag and weaker with heterozygous antigen

Question 4

Review HTLA

High titer low avidity antibody

Answer 4

• Strong plasma reaction but no clinical significance
• Same reactivity in wide range of dilutions
• Often high-incident variable reactive

Question 5

DAT vs IAT

Answer 5

DAT = Body
IAT = Test tube

Question 6

T/F
High incidence means the antibody is clinically relevant

Answer 6

False

Question 7

Issues a high frequency antibody causes in Ab ID

Answer 7

May mask clinically significant positive reactivity from other antibodies

Question 8

Special test to diagnose HTLA

Answer 8

Antibody titer

Question 9

What do we do with HTLA antibodies?

Answer 9

Remove from sample so that underlying allo-antibodies can be tested (can remove by adsorption)

Question 10

What may cause unexplained antibody reactivity?

Answer 10

Low frequency antibody

Question 11

Which antigens may exhibit dosage?

Answer 11

• Kidd
• Duffy
• MNS
• Lutheran
• Rh (C and E, not D)

Question 12

How can you detect dosage on antigram?

Answer 12

If stronger reaction when homozygous and weaker when heterozygous

Question 13

Implications of non-specific antibody

Answer 13

“I don’t know”
-Rachelle

Question 14

Reference labs are required to ID ____

Answer 14

antibodies not on the antigram sheet

Question 15

anti-P1 neutralized by

Answer 15

Hydatid cyst fluid

Question 16

anti-Lewis neutralized by

Answer 16

Saliva

Question 17

anti-Chido/Rogers neutralized by

Answer 17

Serum (complement) or plasma

Question 18

anti-Sda neutralized by

Answer 18

Urine

Question 19

anti-I neutralized by

Answer 19

Human breast milk

Question 20

Mechanism of proteolytic enzymes (e.g., ficin, trypsin, papain)

Answer 20

Remove sialic residues, denature proteins

Question 21

List antigen groups destroyed by enzymes

Answer 21

• Duffy
• MNS
• Ch/Rg
• Xga

Question 22

List antigen groups enhanced by enzymes

Answer 22

• Kell
• Rh (C/c, E/e, D/d)
• Kidd
• P/Glob
• Lewis

Question 23

False positive causes in phenotyping

Answer 23

• Transfused cells
• Positive DAT

Question 24

Selected cells

Answer 24

Made of panel cells from other panel lots or vendors

Question 25

When do you use selected cells?

Answer 25

• Confirm and/or eliminate Ab IDs
• Meet rule-of-three requirement
• ID new Ab when new Ab present

Question 26

Positive DAT ______ all cell testing at AHG

Answer 26

Invalidates