Blood Types

what determines different blood types

the protein and carbohydrate which are attached to the RBC

what do we develop against the antigens we dont have

antibodies

Group A

- antibodies present

- antigens present

- anti B

- A antigen

Group B

- antibodies present

- antigens present

- anti A

- B antigen

Group AB

- antibodies present

- antigens present

no antibodies present

A + B antigens

Group O

- antibodies present

- antigens present

anti A and anti B

only H antigen

where are antibodies found

plasma

where are antigens found

red blood cells

H antigen

draw structure

fucose -a2- galactose -b3-glucose -b3- galactose

A antigen

draw structure

H antigen with N-acetylgalactose attached to first galactose via a3 bond

B antigen

draw structure

H antigen with extra galactose on the first galactose via a3 bond

where is the difference between antigens stored

info stored on chromosome 9

special glycosyl transferase that adds either galactose or n-acetyl galactose onto the H antigen depending on which enzyme you have

group O and chromosome 9

also have chromosome 9

there is a polymorphism which leads to early termination of the enzyme that adds the groups on so that it is not active

blood group compatibility

everyone can donate to themselves

O can donate to everyone

AB can receive from everyone

group O compatibility

no antigen

can be given with to all other blood groups

universal donor

compatibility of group AB

no antibodies, both antigens

cannot donate to A, B, O

but can receive from A,B,O

universal recipient

what happens if an antigen and antibody which are not compatible bind

blood clotting

rhesus factor

Protein determining positive or negative blood type

antibodies against the rhesus factor are only produced on exposure

rhesus factor compatibility

ideally give pos to pos, neg to neg

but can give pos to neg

plasma transfusion

plasma contains important proteins and antibodies

used for pts with liver failure, severe infections and serious burns

platelet function

stops the body from bleeding

platelet transfusion

leukaemia or other types of cancer have low PLT counts

pts with illnesses that prevent body from making enough platelets

red blood cells (pRBC)

iron deficiency

anaemia

pt lost a lot of blood

increases haemoglobin and iron levels whilst also improving amount of oxygen in the blood

inheritance of blood types

A + B are dominant - share a codominance

O is recessive

this means if one parent gives A and another give O the child will have type A

name 2 atypical blood types

cis-AB blood type

bombay blood type

cis-AB

type AB baby from type O parent

glycosyltransferase has bifunctional activity -> cis-AB allele

cis-AB type glycosyl transferase glycosylates H antigen with both galactose and n-acetylgalactoseamine

can confirm presence with PCR

bombay blood type

people who are only appearing to be blood type O but genetically are actually A B or AB

genetic error production of H antigen

no H antigen, can not be glycosylated even if glycosyltransferase present

can only receive transfusion from bombay blood types