Immunohematology Lecture Powerpoint

Question 1

Which Ig typically causes issue when it comes to blood antigens and why?

Answer 1

IgM, because it is pentemeric and has so many binding sites

Question 2

Blood antigen definition

Answer 2

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

Question 3

Most blood antigens are ____ genetically

Answer 3

Co dominant (if the gene is present, the antigen will be expressed - think AB blood type)

Question 4

Naturally occurring antibodies/alloantibodies

Answer 4

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

Question 5

Most common example of alloantibodies, what is the most common example of problematic alloantibodies?

Answer 5

ABO antibodies, Rh antibodies

Question 6

What type of hypersensitivity reaction is a blood transfusion hemolytic response?

Answer 6

A type 2

Question 7

Bombay type

Answer 7

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

Question 8

H substance

Answer 8

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

Question 9

If you are type O blood, you form antibodies against…

Answer 9

….The A and B antigens

Question 10

If you are type A blood, you form antibodies against…

Answer 10

…type B antigens

Question 11

If you are type AB blood, you form antibodies against…

Answer 11

….you do not form ABO antibodies

Question 12

Group O cells are considered a universal ___, while group O plasma is considered a universal ____

Answer 12

Donor, recipient

Question 13

Group AB cells are considered a universal ___, while group AB plasma is considerred a universal ___

Answer 13

Recipient, donor

Question 14

Most Rh antibodies are produced by direct stimulation by these 2 mechanisms

Answer 14

1) pregnancy

2) transfusion

Question 15

The antigen most efficient at eliciting an immune response is the antigen designated ___, a major antigen of the ___ system

Answer 15

D, Rh

Question 16

Du antigen definition and how should they be treated when receiving or donating blood

Answer 16

An inherited D antigen that has weaker recognition by antibodies, should be treated as Rh negative when recipients but Rh positive when donors

Question 17

Rarest ABO and Rh genetic setup

Answer 17

AB, Rh neg

Question 18

Because antiD is a ___ antibody, it is of concern during ___

Answer 18

IgG, pregnancy crossing the placenta and causing hemolysis of fetal RBC’s

Question 19

Rhogam mech of action

Answer 19

• 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)

Question 20

During pregancy, what Rh type do you always assume the fetus is?

Answer 20

Rh positive

Question 21

Rhogam should be given even in the case of…

Answer 21

…miscarriage, stillbirth, natural or elective abortion

Question 22

Direct coomb’s test

Answer 22

A test for hemolytic anemia that checks for antibodies attached to the surface of red blood cells such as on a new born

Question 23

Indirect coombs test

Answer 23

A test for hemolytic anemia that checks for antibodies floating in serum, such as on a mother

Question 24

Protocol for a woman given rhogam is to…

why?

Answer 24

….carry a card that identifies this in case of an emergency
-because she will appear Rh positive even though she may be Rh negative