Question

Mitch was working in the blood bank and the phone rang at his station, interrupting the AHG test he was performing. He forgot to add AHG reagent to his test tubes before he centrifuged them. How would this affect the results of the test? How would this problem be detected in testing?

Answer 1

This test detects clinically significant unexpected antibodies that have coated cells invitro or invivo.Red cells coated with complement or IgG antibodies do not agglutinate directly when centrifuged. These cells are said to be sensitized with IgG or complement.

In order for agglutination to occur an additional antibody, which reacts with the Fc portion of the IgG antibody, or with the C3b or C3d component of complement, must be added to the system.

This will form a "bridge" between the antibodies or complement coating the red cells, causing agglutination.

Thus this bridge will not be formed and hence agglutination will not occur.Antibodies are a part of our immune system. They fight germs, but sometimes they make a mistake and target our body's healthy cells instead.This test helps in detecting these antibodies that attack red blood cells. So when blood do not agglutinate it may be interpreted as negative test and now can be given to the patient.But when this blood is given to the patient and he develops problems we again test and find that antibodies have been formed against it's red blood cells. So this problem can be detected by testing it again with AHG.This would reveal the mistake done at the blood bank.

Regards