Lec 15 - Blood Groups and Compatibility Testing Flashcards
Two main naturally occurring antibodies to red cell antigens? Which of these two antibodies are found in individuals of each ABO group?
“Anti-A and anti-B
for example: a type A person will make B-antibodies”
why is ABO system the most important red blood group system for transfusion therapy?
a mismatch will cause an intravascular hemolysis transfusion reaction
Direct antiglobulin test (DAT) - main component source (patient or reagent?)
“What is attached to the RBC?
Wash RBC just to have the cells and add our test so see if you get addlutination”
What is DAT capable of detecting?
medication issues?
What is the indirect antiglobulin test (IAT)? Major purpose?
Testing the recipient serum antibodies for reaction. Adding donor RBC to see if get reaction
Three steps of blood compatibility testing? Purpose of each step?
“Blood type -
Antibody screen
crossmatch - serum from patient + donor RBC mix “
In emergency give what kind of blood?
O neg -universal RBC donor (in emergengy give O neg to females!)
Immunohematology specifically deals with what?
red cells and plasma
Major antibody we are concerned with in transfusion medicine?
IgG (and IgM and sometimes IgA)
Patients die more often from which type of hemolysis?
“INTRAVASCULAR (severe and immediate IgM –> complement –> DIC and death)
FYI-Extravascular (delayed IgG) RBC marked for destruction by RE system = jaundice)”
Hemolytic disease of the fetus and newborn?
IGM DOES NOT CROSS BUT IGG DOES!
A gene has what enzyme? Adds to what substance?
N-galactosaminyltransferase – adds sugar onto H-substance
B gene has what enzyme? Adds to what substance?
D-Galatosyltransferase – adds sugar onto H-substance
No H substance? What happens?
Youre a bombay – super rare .. Need super special blood
Newborn transfusion - which type to give?
Doesn’t matter bc baby antigens don’t dev until about 4month
