Contents
When do ABO discrepancies occur?
An ABO discrepancy occurs when the results of forward and reverse typing do not match. The reactions shown are described below in descending order: Patient red cells with reagent anti-A: negative reaction. Patient red cells with reagent anti-B: 4+ agglutination.
What are the four ABO discrepancies?
The table that follows provides four useful categories. Weak, missing reactions (including mixed field) in the forward (red cell) typing. Unexpected reactions in the forward (red cell) typing. Weak or missing reactions in the reverse (serum) typing.
What do you mean by ABO discrepancy?
A generic term for a variety of situations in which the interpretation of a patient or donor’s ABO grouping results is unclear. ABO discrepancies happen for a wide variety of reasons, including technical errors, problems with red cell antigens, or problems with serum antibodies. …
How do you fix ABO discrepancies?
In this situation, the discrepancy can be resolved by washing and re-suspending patient RBCs in saline, followed by repeat forward typing with anti-A and anti-B.
What is detected in ABO reverse typing?
The back/reverse type mixes an individual’s plasma with reagent RBCs positive for antigen A, and separate reagent RBCs positive for B antigen. The test also measures visual agglutination or lack of agglutination. Most ABO antibodies are immunoglobulin (Ig) M.
What is reverse typing?
Reverse typing – A blood typing procedure where patient serum is mixed with reagent A cells and reagent B cells. The results should be the opposite of forward typing. Serum – The straw-colored fluid remaining when blood is clotted.
How do you reverse blood typing?
The patient’s serum is mixed with known red cells in a test tube. A specified number of drops of patient serum are placed into each of three properly labeled tubes. A specified number of drops of known A1 cells are added to the A tube, and a specified number of drops of known B cells are added to the B tube.
What are the other names for ABO reverse typing?
In ABO grouping, the testing of the patient’s serum or plasma against, at minimum, A1 and B reagent RBCs (the process is also known as “serum grouping” or the slang term “back typing“).
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When do you have an ABO discrepancy?
ABO discrepancies describe unexpected reactions in forward or reverse groupings Serum and RBC reactions are usually very strong (3+ or 4+) Weak reactions usually indicate an ABO discrepancy They are due to technical errors, problems with the patients RBCs, plasma or both
What causes an ABO blood group discrepancy?
ABO blood Group System: ABODiscrepancies: • ABO discrepancies happen when there is no match in results between forward and reverse grouping(Cell type and Back type). • Since production of ABO antigens is genetically controlled, they are less vulnerable toproblems than does the production ofABO antibodies.
Why are there so many Abo discrepancies in India?
While a discrepancy does not appear at first, the problem surfaces when the patient’s serum is tested against O cells. Since anti-H is present they will agglutinate these cells. This is a very rare blood type to encounter; mainly found in India, it is the result of consanguineous marriage (both partners descending from the same ancestor).
What causes ABO group discrepancies in three case studies?
The most common causes for these discrepancies are: 1) Unexpected ABO isoagglutinins, as represented in Case History #3. This type of discrepancy is seen in Group A2, A2B and some other subgroups of A. To resolve the discrepancy, several examples of Group A1, A2, B, and O red cells and an auto-control should be tested.
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