Immunohematology Lecture Powerpoint Flashcards
anna mae fuking heck
Which Ig typically causes issue when it comes to blood antigens and why?
IgM, because it is pentemeric and has so many binding sites
Blood antigen definition
Groups of over 700 known Proteins, lipoproteins and carbohydrates that sit on the surface of RBC membranes with certain ones often being based on genetic expression of the individual, to which an antibody response can be mounted against
Most blood antigens are ____ genetically
Co dominant (if the gene is present, the antigen will be expressed - think AB blood type)
Naturally occurring antibodies/alloantibodies
Exceptions to the antibody formation rule that exposure to an antigen via pregnancy or transfusion is required to form an antibody, these can be formed from food or other object exposure over a life time
Most common example of alloantibodies, what is the most common example of problematic alloantibodies?
ABO antibodies, Rh antibodies
What type of hypersensitivity reaction is a blood transfusion hemolytic response?
A type 2
Bombay type
An hh genotype resulting in lack of an H substance on RBC, very rare and result in only being able to receive blood from their own as they have a hemolytic reaction to H type
H substance
A carbohydrate chain present on almost all human’s RBC unless they are rare hh type, allows for binding of A and B enzymes for blood typage
If you are type O blood, you form antibodies against…
….The A and B antigens
If you are type A blood, you form antibodies against…
…type B antigens
If you are type AB blood, you form antibodies against…
….you do not form ABO antibodies
Group O cells are considered a universal ___, while group O plasma is considered a universal ____
Donor, recipient
Group AB cells are considered a universal ___, while group AB plasma is considerred a universal ___
Recipient, donor
Most Rh antibodies are produced by direct stimulation by these 2 mechanisms
1) pregnancy
2) transfusion
The antigen most efficient at eliciting an immune response is the antigen designated ___, a major antigen of the ___ system
D, Rh
Du antigen definition and how should they be treated when receiving or donating blood
An inherited D antigen that has weaker recognition by antibodies, should be treated as Rh negative when recipients but Rh positive when donors
Rarest ABO and Rh genetic setup
AB, Rh neg
Because antiD is a ___ antibody, it is of concern during ___
IgG, pregnancy crossing the placenta and causing hemolysis of fetal RBC’s
Rhogam mech of action
- Immunize every Rh neg mom at 28 weeks pregnant (it lasts 12 weeks, so to term) with an then at birth get another immunization of it
- This allows the anti-D antibody to destroy fetal cells that have leaked into mom’s circulation without crossing placenta and before mom mounts her own antigenic response
- If amniocentesis occurs at 16 weeks then rhogam is given at 16 weeks and then 12 weeks later again and then at delivery again (3 times, unless baby and mom are Rh neg)
During pregancy, what Rh type do you always assume the fetus is?
Rh positive
Rhogam should be given even in the case of…
…miscarriage, stillbirth, natural or elective abortion
Direct coomb’s test
A test for hemolytic anemia that checks for antibodies attached to the surface of red blood cells such as on a new born
Indirect coombs test
A test for hemolytic anemia that checks for antibodies floating in serum, such as on a mother
Protocol for a woman given rhogam is to…
why?
….carry a card that identifies this in case of an emergency
-because she will appear Rh positive even though she may be Rh negative
