Weinir, fisher, rosenfield

Question 1

Weiner to Fisher-race

Ro
R1
R2
Rz
Ry
r
r'
r''

Answer 1

Ro = Dce
R1 = DCe
R2 = DcE
Rz = DCE
r = ce
r' = Ce
r'' = cE
ry = CE

Question 2

Rosenfield - FisherRace - Wiener

`Rh1 - D - 
Rh2 - C - 
Rh3 - E - 
Rh4 - c - 
Rh5 - e -

Answer 2

Rho
rh'
rh''
hr'
hr''

Question 3

Immunogenicity of common Rh antigens

Answer 3

D > c > E > C > e

Question 4

Common genotypes:

Answer 4

R1r
R1R1
rr
R1R2
R2r
R2R2

Question 5

Rarer genotypes:

Answer 5

r'r
r'r'
r''r
r''r''
Ror (RoRo)
r'r'' (ryr)

Question 6

FALSE-POSITIVES:

Answer 6

1. Cell suspension too heavy
2. Cold agglutinins
3. Test incubated too long or drying (slide)
4. Rouleaux
5. Fibrin interference
6. Contaminating low-incidence antibody in reagent
7. Polyagglutination
8. Bacterial contamination of reagent vial
9. Incorrect reagent
   selected
10. Centrifugation too long
11. rpm too high

Question 7

FALSE-POSITIVES AND ITS CORRECTIVE ACTION

1. Cell suspension too heavy
2. Cold agglutinins
3. Test incubated too long or drying (slide)
4. Rouleaux
5. Fibrin interference
6. Contaminating low-incidence antibody in reagent
7. Polyagglutination
8. Bacterial contamination of reagent vial
9. Incorrect reagent
   selected
10. Centrifugation too long
11. rpm too high

Answer 7

1. Adjust suspension, retype
2. Wash with warm saline, retype
3. Follow manufacturer’s instructions precisely
4. Use saline-washed cells, retype
5. Use saline-washed cells, retype
6. Try another manufacturer’s
   reagent or use a known serum antibody
7. See chapter on polyagglutination
8. Open new vial of reagent,
   retype
9. Repeat test; read vial label carefully
10. Repeat test using shorter centrifugation time
11. Repeat test using lower rpm

Question 8

FALSE-NEGATIVES:

Answer 8

1. Immunoglobulin-coated cells
(in vivo)
2. Saline-suspended cells (slide)
3. Failure to follow manufacturer’s directions precisely
4. Omission of reagent manufacturer’s directions
5. Resuspension too vigorous
6. Incorrect reagent selected
7. Variant antigen
8. Reagent deterioration

Question 9

FALSE-NEGATIVES AND ITS CORRECTIVE ACTION:

1. Immunoglobulin-coated cells
(in vivo)
2. Saline-suspended cells (slide)
3. Failure to follow manufacturer’s directions precisely
4. Omission of reagent manufacturer’s directions
5. Resuspension too vigorous
6. Incorrect reagent selected
7. Variant antigen
8. Reagent deterioration

Answer 9

1. Use saline-active typing reagent
2. Use unwashed cells
3. Review directions; repeat test
4. Always add reagent first and check before adding cells
5. Resuspend all tube tests gently
6. Read vial label carefully; repeat
7. Refer sample for further investigation
8. Open new vial