ABO Discrepancies Flashcards
Most common ABO discrepancy
Group I - weak or missing antibodies
Group I discrepancies with produce an abnormal
reverse type
When the forward and reverse typing do not match it is considered a
ABO discrepancy
Why isn’t reverse typing performed on infants?
Infants don’t form their own antibodies until 3-6 months of age
Term referring to mixed populations
chimerism
Which patients and when can ABO discrepancies occur?
Infants and elderly
hypogammaglobulinemia and chimerism
Group II discrepancies are classified by
weak or missing antigens
Group II discrepancies with produce abnormal
forward type
Occurrences that can produce a Group II discrepancy
A and/or B subgroups
Leukemia, Hodgkin’s Disease
Cancers
Antibodies to low incidence antigens in reagents
Acquired B
How can a person develop acquired B?
An infection in the GI tract by a gram negative organism. This organism can deacetylate the A antigen, making it appear as a B antigen
What can be done to differentiate a true B from an acquired B agglutination?
Acidify the anti-B to a pH of 6.0
True B antigens will react, acquired will not.
Group III discrepancies are classified as
pseudoagglutination (rouleaux)
Pseudoagglutination can occur due to
elevated globulin
plasma expanders
Wharton’s Jelly
Elevated fibrinogen
What can be done to disperse rouleaux?
add a couple drops of saline to the sample to disperse the cells
Group IV discrepancies can be classified as
polyagglutination
