High and Low Frequency Antigens Flashcards
Exam 2
How are low frequency antigens usually detected in testing?
It is usually detected on an incompatible crossmatch that happens to positive for the antigen since the screen and panel are usually negative. It could also be caught due to a transfusion reaction or HDFN.
How are high frequency antigens usually detected in testing?
These should be detected on the panel and screen since every cell should react with the antibody. The autocontrol here is usually negative.
Is it more difficult to find blood for patients with antibodies to high frequency antigens or antibodies to low frequency antigens and why?
Blood for patients with antibodies to high frequency antigens is harder to find because most donor red cells will be positive for that antigen.
What does the term hemizygous mean?
It means the gene is only found on one chromosome as in the case of the Y chromosome in males.
Does anti-Xg(a) cause HDFN or TRXNs?
No
Which Wright antibody is a common warm autoantibody?
Anti-Wr(b)
Which high frequency antibody causes severe HDN and hemolytic TRXNs and also activates complement?
Anti-Vel
Which high frequency antibody can be removed by using neutralization techniques with the soluble form found in urine?
Anti-Sd(a)
What does anti-Sd(a) agglutination look like under the microscope?
Small, refractile, shiny agglutinates
Which high frequency antigens are found on the 4th component of complement?
Chido and Rogers
Which antibodies are weakly reactive and quickly disappear making them hard to identify?
Dombrock
What is the reaction strength normally for an HTLA antibody?
Weaker - 1+
How high to HTLA antibodies tend to titer?
1:64 or higher
Are HTLA antibodies clinically significant?
No
Is Di(b) a high or low frequency antigen?
High
