ABO

Question 1

Discrepancy that happens between forward and
backward grouping due to weakly reacting or
missing Antibodies

Answer 1

Group 1

Question 2

More common out of the 4 ABO discrepancies

Answer 2

Group 1

Question 3

group 1 is due to?

Answer 3

weakly reacting or missing antibodies

Question 4

group 1 abo discrepancies is found in?

Answer 4

1. newborns and elders
2. chronic lymphocytic leukemia, lymphoma
3. imunosuppressive drugs
4. congenital agammaglobulinemia
5. immunodeficiency status
6. bone marrow transplant
7. chimerism
8. abo subgroups

Question 5

why do you find nothing when testing for antibodies in newborns

Answer 5

lack of antibodies. they develop their own antibodies at around 3-6 months

Question 6

Existence of 2 blood groups in your
system.

Answer 6

Chimerism

Question 8

resolution for group 1 discrepancies

Answer 8

1. review patient’s history
2. enhance serum reaction

Question 9

ways to enhance serum reaction

Answer 9

• serum + reagent A1 and B cells = incubate at room temp for 15-30 minutes
• incubate at 4C for 15-30 mins if no reaction after centri
• add 1 or 2 drops more plasma/serum to the test

Question 10

due to weak reacting or missing antigens

Answer 10

GROUP 2

Question 11

causes of group 2 discrepancies

Answer 11

1. subgroups of A and B
2. disease conditions
   
   • low antigen expression
   • leukemia, lymphoma
   • hodgkins disease
3. increase blood group specific soluble substances

Question 12

resolution for group 2 discrepancies

Answer 12

• incubate mixture at room temp for 30 mins
• if negative, incubate at 4C for 5-30 minutes

Question 13

group 3 discrepancy is due to what abnormalities?

Answer 13

protein or plasma abnormalities

Question 14

what are the cause of group 3 discrepancy

Answer 14

1. rouleaux formation or pseudoagglutination
2. increase globulin
3. multiple myeloma
4. waldenstroms macroglobulinemia
5. advance hodgkin’s lymphoma
6. increase fibrinogen
7. plasma expanders
8. whartons jelly

Question 15

Group 3 discrepancy resolution

Answer 15

saline replacement technique (Remove serum, replace with equal volume of saline /wash)

Question 16

Group 4 discrepancy is due to?

Answer 16

Antigen reaction or miscellaneous

Question 17

Cause of group 4 discrepancy

Answer 17

1. Cold Reactive Antibodies
2. Unexpected ABO isoagglutinins

Question 18

resolution for group 4 discrepancy: Cold Reactive Antibodies

Answer 18

-Incubate mixture at 37C for a
short period
- Washed with saline at 37C three times
and retyped
-Or treated with 0.01 M dithiothreitol -
disperses IgM related agglutination

Question 19

Resolution for group 4 discrepancy: unexpected isoagglutinins

Answer 19

Serum groupings can be repeated using at least
3 examples of A1, A2, B cells, O cells, and an autologous control (Patient’s serum, mixed
with patient’s cells)

Question 20

Principle of forward typing

Answer 20

Testing with both Anti-A and Anti-B is necessary to determine if red blood cells possess or lack A and/or B blood group antigens.

Question 21

formation of ABH antigens result from interaction of gene at?

Answer 21

3 diff loci

Question 22

Reagents used for forward typing contain __ as preservative

Answer 22

sodium azide 0.1%

Question 23

storage & temp for forward typing reagents

Answer 23

Store at 2 to 8°C. May be at room temperature (20 to 30°C) while in use.

Question 24

Specimen used for forward typing

Answer 24

EDTA anti coagulated blood

Question 25

using known sources of commercial antisera (anti a, anti b)

Answer 25

Forward typing

Question 26

What does forward typing detect

Answer 26

Detect antigens on an individual's RBC

Question 27

using known reagent RBCs (A & B cells)

Answer 27

Reverse typing

Question 28

What does reverse typing detect

Answer 28

ABO antibodies in patients serum

Question 29

Principle of reverse grouping

Answer 29

Reverse (serum) grouping is designed to check for the presence of the expected ABO blood group antibodies by testing the serum of the patient with a pool of known A (A1) cells and known B cells.

Question 30

RCS used in reverse typing

Answer 30

2-5% Human Red Cell Suspension (A cells and B cells)

Question 31

indication of marked hemolysis in abo reverse typing

Answer 31

instability or contamination and the reagent must be discarded.