Lecture 15- Haematology Lecture 3 Flashcards
What happens if you need blood? What sources can be available to replenish your lack of blood?
- Saline, a salt solution, can be used to increase blood volume (for loss of <1.5L)
- Fresh frozen plasma
- Platelets
- Packed red blood cells – whole blood
from which most of the plasma and
the leukocytes have been removed. - Replacement coagulation factors – for patients with genetic disorders
- Activated coagulation factors. E.g. FVIIa, thrombin
- Fibrinolysis inhibitors
How does blood donation work? What temperature and conditions does blood need to be kept in?
- 1 unit = 450mL; collected into
anticoagulant - Donations are refrigerated (4oC)
overnight then separated as shown
What are antigens?
- Red blood cells carry reactive groups (antigens)
on the cell surface, which you have inherited
from both of your parents, these are made up of:
✓Glycoproteins,
✓Glycosphingolipids
✓Carbohydrate groups - Antigens on the surface determine a person’s
Blood Group
What reactive groups do red blood cells carry on their surface and what are these reactive groups made up of?
blood group antigens
What determines someone’s blood group?
the antigens on the surface of their RBCs
Why is it important to match donor and recipient immunity?
Reduction of Rejection Risk:
The immune system plays a critical role in detecting and eliminating foreign substances, including transplanted organs or tissues, through a process known as rejection.
Mismatched immune responses between the donor and recipient can trigger an immune reaction against the transplanted organ, leading to rejection and potential organ failure.
What is natural immunity?
- Natural antibodies are mostly IgM isotype
- IgM Ab bind to a particular antigen or
pathogen even if the host has never been
exposed to it - Many are reactive to structures common to
many species such as nucleic acids, heat shock
proteins, carbohydrates, and phospholipids. - Antigens bound strongly
What isotype are natural antibodies usually? How does this isotope bind and what are their characteristics?
- Natural antibodies are mostly IgM isotype
- IgM Ab bind to a particular antigen or
pathogen even if the host has never been
exposed to it - Many are reactive to structures common to
many species such as nucleic acids, heat shock
proteins, carbohydrates, and phospholipids. - Antigens bound strongly
How does immunity work? How do antibodies cause agglutination? What does agglutination cause?
- Antibodies recognise antigens
on the erythrocyte cell surface. - Antibodies can bind to multiple
erythrocytes at the same time. - The binding of antibody to the
erythrocyte(s) causes a clumping
effect known as agglutination. - Agglutination causes a pore to
be formed in the cell membrane,
killing the cell.
What are the structures of the ABO blood antigens?
look at the slides
What happens as a result of ABO-incompatible transfusions?
If A and/or B antigen is NOT present on erythrocyte, corresponding
antibodies are in serum
* ABO incompatible transfusion results in a very rapid haemolysis of
transfused cells
What are the abundances of the ABO groups in the UK populations?
43%: type A
9%: Type B
3%: Type AB
45%: Type O neither A or B
What happens if you give someone the wrong type of blood?
- ABO incompatible transfusion results in a very rapid haemolysis of
transfused cells
How does the Rh system work? How is the Rh system different from the ABO system?
- Two proteins are responsible for
different serotypes: D and C/E - D is very antigenic and most
important, Rhesus positive or
negative relates to D - C/E are 2 different regions of the
same protein - These are small antibodies (IgG)
that can cross the placenta
Why is it dangerous if the mother and fetus have different Rh types?
the mothers body can produce antibodies that determine the babies blood to be foreign and so will attack the foetus
