[JT U2] ABO Discrepancies

Question 1

Unexpected reactions may be due to (2):

Answer 1

1. Extra positive reaction
2. weak or missing reaction

• must also be investigated

Question 2

Discrepant results are released/not released

Answer 2

Not released

Question 3

What do you do when you encounter a discrepancy?

Answer 3

investigate immediately

Question 4

This happens whenever forward and reverse typing are different

Answer 4

ABO discrepancies

Question 5

ABO Discrepancies can be due to (4)

Answer 5

serum
patient’s RBC
Both serum and patient’s RBC
clerical error

Question 6

first thing to do when there is a discrepancy

Answer 6

new sample must be drawn and repeat the test

Question 7

You may administer group __ ____________ RBCs during emergencies or if discrepancies cannot be solved

Answer 7

O, Rh compatible

Question 8

4+, 3+, 2+, are considered ____ reactions

Answer 8

strong/true

Question 9

1+ and weak reactions are usually _________ and are the cause of discrepancies

Answer 9

repeated

Question 10

Group of Discrepancy caused by False negative results in Reverse Typing

Answer 10

Group I Discrepancies

Question 11

Most common type of discrepancy

Answer 11

Group I Discrepancies

Question 12

If a sample from a newborn has had a Group I discrepancy, we must follow the ___________ result

Answer 12

forward typing

Question 13

Type of subgroups that can give Group I discrepancy due to low antibodies

Answer 13

ABO subgroups

Question 13

Group I discrepancies are usually seen in

Answer 13

• Newborns
• Elderly people
• AIDS patients
• Patients w leukemia / hypogammaglobulinemia
• patients with agammaglobulinemia
• patients with bone marrow or HPC transplants
• Patients whose existing ABO antibodies may have been diluted by plasma transfusion

Question 13

___________ and ___________ must always be tested with reverse typing

Answer 13

Auto control; O cell control

Question 13

Autocontrol components (2)

Answer 13

Px RBC + Px Serum

Question 14

+ in Autocontrol

Answer 14

Autoantibody

Question 15

(-) in Autocontrol

Answer 15

Alloantibody

Question 16

+ In O cell control

Answer 16

Bombay

Question 17

small agglutinates in a sea of unagglutinated cells

Answer 17

Mixed-field agglutination

Question 18

Mf is usually associated with what ABO subgroup?

Answer 18

A3

Question 19

Discrepancies caused by False (-) reactions in Forward typing

Answer 19

Group II Discrepancies

Question 20

Least encountered discrepancies

Answer 20

Group II Discrepancies

Question 21

Discrepancies caused by weakly reacting or missing antigens

Answer 21

Group II Discrepancies

Question 22

what causes forward typing to have discrepancies?

Answer 22

Subgroups - Associated with presence of low antigen - enzymes werent converted to A or B

Question 23

What may yield weakened A or B antigens in Group II discrepancies?

Answer 23

Leukemias

Question 24

Immunodominant sugar in Acquired B phenomenon

Answer 24

D-galactosamine

Question 25

Resolution for group II discrepancies: Incubate at __ for __ minutes

Answer 25

RT; 15-30

Question 26

Control in Forward Typing

Answer 26

BSA

Question 27

Control in Reverse Typing

Answer 27

O cell

Question 28

What neutralizes Anti-A and Anti B?

Answer 28

BGSS Blood group soluble substances

Question 29

BGSS may be increased by?

Answer 29

cancers/leukemias

Question 30

Done to remove plasma component that may interfere with the tests

Answer 30

RBC suspension can be used sa Group II and III discrepancies

Question 31

Discrepancies caused by False (+) reactions in Forward and Reverse Typing

Answer 31

Group III Discrepancies

Question 32

Group III Discrepancies are caused by ____ or ______ abnormalities

Answer 32

protein or plasma

Question 33

Group III Discrepancies result in _________________

Answer 33

Rouleaux / Pseudoagglutination

Question 34

stacking of RBC in a coin like fashion

Answer 34

Rouleaux formation

Question 35

why do you encounter rouleaux formation in Group III Discrepancies?

Answer 35

due to having plasma samples - plasma contains Acute-phase reactants like fibrinogen that may increase during inflammation

Question 36

Technique or resolution used to differentiate between true agglutination and pseudoagglutination

Answer 36

Saline replacement technique

Question 37

remove serum and replace equal volume of saline

Answer 37

Saline replacement technique

Question 38

+ result of true agglutination in saline replacement technique

Answer 38

RBC clumping remains after addition of saline

Question 39

Thorough washing of cord blood samples with saline (6-8) is done in Group __ Discrepancies

Answer 39

III

Question 40

Discrepancies between forward and reverse groupings due to miscellaneous problems

Answer 40

Group IV discrepancies

Question 41

Causes of Group IV Discrepancies:

Answer 41

- Cold reactive autoantibodies - circulating RBCs of more than one group due to RBC transfusion or BM/SC transplant - Unexpected ABO isoagglutinins - unexpected non-ABO alloantibodies

Question 42

This discrepancy affects forward typing through fingerpricking

Answer 42

Group III discrepancy

Question 43

Forward: Anti-A (+), Anti-B (-) Reverse: A cell (-), B-cell (-) Patient is a newborn and has a blood Type A. Under what discrepancy does this fall under?

Answer 43

Group I

Question 44

Forward: Anti-A (-), Anti-B (-) Reverse: A cell (-), B-cell (4+) Under what discrepancy does this fall under?

Answer 44

Group II

Question 45

Forward: Anti-A (4+), Anti-B (-) Reverse: A cell (1+), B-cell (4+) Specimen is plasma. Microscopic analysis shows Rouleaux formation of RBCS. Under what discrepancy does this fall under?

Answer 45

Class III