ABO discrepancies

Question 1

Blood type: Forward type

Answer 1

• 1 drop antisera: anti-A, anti-B
• 1 drop cell suspension
• Positive reaction (3 - 4+) = Antigen Present
• Negative reaction = lacks antigen

Question 2

Reverse Type

Answer 2

• 2 drops serum/plasma
• 1 drop reagent A1 cell or B cell
• Positive reaction (2 - 4+) = Antibody Present
• Negative reaction = lacks antibody

Question 3

ABO discrepancies occur when the

Answer 3

when the forward grouping does not agree with
the reverse grouping

Question 4

ABO discrepancies

Problems with the patient serum

Answer 4

Reverse grouping

Question 5

Problems with the patient’s red cells

Answer 5

Forward grouping

Question 6

A discrepancy may be present if

Answer 6

• Agglutination is weaker than expected
• Expected reactions are missing
• Extra reactions are noted

Question 7

A ABO discrepancy must be resolved prior to

Answer 7

Reporting a patient or donors ABO group

Question 8

Blood Type Discrepancies:
Technical Considerations -Resolutions

Answer 8

• Make suspensions with saline
• Review and correct any and all technical factors
• Obtain patient history: age, diagnosis, transfusion history,
  medications, pregnancies
• Obtain new specimen

Question 9

Blood type discrepancies

Missing/ weak reactions

Answer 9

1. Repeat testing
2. Check specimen for mislabel
3. Check reagent control results
4. Obtain patient history
5. Incubate serum and cells at RT or 4oC

Question 10

Blood Type Discrepancies:
Short Cold Panel

Test against

Answer 10

group O adult, group O cord and auto-
control to detect cold agglutinins

Question 11

Cold agglutinin=

Answer 11

anti-I

Question 12

Cord cells have little or no _____ at birth, they have _____

Answer 12

i

Question 13

Blood Type Discrepancies:
Extra reaction

Answer 13

1. Repeat testing
2. Check specimen for mislabel
3. Check reagent control results
4. Obtain patient history

Question 14

Rouleaux

Can cause extra ______

Answer 14

Reactions in forward and reverse grouping

Question 15

Rouleaux

what appearance

Answer 15

Stack and coins appearance

Question 16

Rouleaux

Stronger at

Answer 16

IS and weak reaction at
37oC; NO reaction at AHG phase

Question 17

Rouleaux

Associated with increased _______

Answer 17

serum
protein (globulins)
* Multiple myeloma
* Waldenstrom’s macroglobulinemia (WM)
* Hydroxyethyl starch (HES), dextran, etc

Question 18

Rouleaux can be fixed with

Answer 18

Saline replacement

Question 19

Mixed Field

Have two what

Answer 19

• 2 cell populations

Question 20

Mixed field

What causes mixed fields

Answer 20

• ABO subgroups (A 3)
• Receiving non-ABO type specific RBCs
• Bone marrow or hematopoietic stem
  cell transplant
• Chimerism

Question 21

A2 subgroup

Answer 21

• Patient group A with agglutination
  of A1 cells

Question 22

A2 subgroup

what lectin is used

Can’t be transfused within the last

Answer 22

• Test patient cells with anti-A1,
  Dolichos biflorus
• Cannot be transfused in last 3 months

Question 23

A2 subgroup

Test what against what

Answer 23

• Test patient serum/plasma with A2
  cells

Question 24

A2 subgroup is the most common what

Answer 24

• MOST COMMONLY encountered
  discrepancy

Question 25

Acquired B Phenotype - B (A)

Answer 25

Forward= AB, reaction with anti-B weak

Serum contains anti-B

Question 26

Acquired B Phenotype - B (A)

• Phenomena associated with

Answer 26

• colon or rectal cancer
• Gram negative sepsis (E. coli)
• Intestinal obstruction

Question 27

Acquired B phenotype- B(A)

Increased detection with

Answer 27

monclonal anti-B

Question 28

Acquired B Phenotype

___ phenotype

Answer 28

B(A)