Transfusion Medicine Flashcards
What is the difference between forward typing and reverse typing?
Forward = mixing the patients red blood cells with a serum containing anti-A, anti-B and anti- AB and seeing which one they agglutinate with. If they don’t agglutinate with any, that means they are O, if they agglutinate with all, that means they are AB.
Reverse typing = the patients sera is exposed to commercially available A cells and B cells to see which one the serum antibodies react with. If theres no agglutination with A cells, that means they don’t have A antibodies so they have A antigen on their RBC. Same for B. no agglutination would mean AB blood.
Which blood type has only H Ag?
Type O blood
What blood type has H + A Ag?
A blood
Which blood type has H + B Ag?
B blood
which blood type has H + A + B?
AB Blood type
What is a secretor? (Se)
Someone who is capable of making ABO antigens in their secretions and plasma
What is the Bombay phenotype?
Blood cells with the absence of H antigen (hh)
Who can Bombay phenotype people receive blood from?
Bombay blood (because their blood has anti H antibodies)
Are Rh anti-bodies naturally occurring?
Nope - exposure to the antigen is needed to make anti bodies
What are the antigens in Rhesus system?
D, Cc, Ee
What does Kell Kill’s mean?
Anti-K is the next most common immune red cell antibody. It can cause hemolytic disease of the newborn and hemolytic transfusion reaction.
What immunoglobulin does anti-Kell present as?
IgG
What is seen on the peripheral blood smear of McLeod phenotype?
Acanthocytes and hemolytic anemia
Chronic granulomatous disease is caused by a deficiency in which enzyme?
NADH oxidase -> no H202 to destroy microbes
What are the antigens present in the Kidd system?
Jka and Jkb
What does treacherous Kidds mean?
Delayed hemolytic transfusion reaction
Because antibodies disappear rapidly so are often not seen on initial AB screen and cross match.
What are the antigens in the Duffy system?
Fya and Fyb
Why are African Americans resistant to plasmodium vivax?
They have the Fyab- phenotype which confers resistance to that plasmodium
Which immunoglobulin will anti Fy antibodies present as? Which reactions can it cause? (Duffy dies)
IgG; HDN and hemolytic transfusion reactions
Which immunoglobulin does anti-M antibody present as?
IgM
What does Lewis Lives mean?
Lewis antibodies are clinically insignificant because transfused red cells shed their Lewis antigens and acquire the Lewis phenotype of the recipient
Also, the antibodies are absorbed by free serum Lewis antigens onto the RBC membrane
When should the specimen from collection be labeled?
At the bedside!!! With time, date and initials of the phlebotomist
What is the difference between type and screen (T&S) and crossmatching?
Type and screen only detects ABO, Rh, and Ab screen
Cross match is actual testing of patients serum compatibility with donor cells
What does the antibody screen aka indirect antiglobulin test aka indirect Coombs test detect?
Antibodies in the patients serum against antigens on commercially available RBCs
What does the direct Coombs test detect?
Autoimmune hemolytic anemia and transfusion reaction work up
What does the indirect Coombs test used for?
Used prior to the blood transfusion and in prenatal testing of pregnant women
What antibodies do you detect at room temperature?
Cold antibodies: IgM
What antibodies do you detect at 37C?
Warm antibodies: IgM-IgG; IgG
Rh, Kell, Kidd and Duffy
What antibodies do you detect with anti human antibodies?
Warm antibodies; IgG that coats the RBC membrane