Blood groups and transfusion

Question 1

How is ones blood group determined

Answer 1

• Sugar residues form the ABO blood group type
• Proteins for the rhesus blood group type
• Your genes determine which sugar/ protein is expressed and therefore your blood group

Question 2

Where are blood groups lcoated

Answer 2

On the surface of the cell- red cell surface has lipid bilayer containing sugar and protein residues

Question 3

What are red cell antigens

Answer 3

Substances on the surface of a red cell that can stimulate the formation of antibodies

Question 4

What are autoantibodies

Answer 4

React with antigens present on a persons own red cells

Question 5

What are alloantibodies

Answer 5

Produced by the person against antigens not present on own red cells

Question 6

How does agglutination work

Answer 6

• Red cells express antigens
• Antibodies to that antigen bind red cells together via antigens
• Causes cell destruction

Question 7

What kind of antibodies are ABO antibodies

Answer 7

IgM and IgG (mostly G)

Question 8

Why are IgM antibodies known as cold acting

Answer 8

They bind at room temp

Question 9

What antibody does blood group A contain in plasma

Answer 9

anti-b

Question 10

What antibody does group group B contain in plasma

Answer 10

Anti-a

Question 11

What antibody does blood group O contain in plasma

Answer 11

Anti-a and Anti-B

Question 12

What antibody does blood group AB contain in plasma

Answer 12

No ABO in plasma

Question 13

What are the possible genotypes for phenotype blood group A

Answer 13

AA, AO

Question 14

What are the possible genotypes of phenotype blood group B

Answer 14

BB, BO

Question 15

What are the possible genotypes for phenotype AB

Answer 15

AB

Question 16

What are the possible genotypes for phenotype O

Answer 16

OO

Question 17

Name the blood groups in order of frequency amognst caucasian people

Answer 17

A,O, B, AB

Question 18

Name the blood groups in order of frequency amongst asian people

Answer 18

B, A, 0, AB

Question 19

Which blood type is the universal donor and why

Answer 19

Group O because they have no antigens and plasma is not donated in great quantities

Question 20

If patient is group a, who can donate

Answer 20

A or O

Question 21

If patient is group b who can donate

Answer 21

B or O

Question 22

If patient is group AB who can donate

Answer 22

ab, a, b or o

Question 23

If patient is group O who can donate

Answer 23

O

Question 24

What kind of antibodies are involved in Rh blood group

Answer 24

Immune antibodies- only exposed if person exposed to antigen through transfusion, pregnancy or transplantation

Question 25

What antigens are involved in Rh blood groups

Answer 25

C/ c D or no D (no D is written as d) E or e

Question 26

How are the antigens in Rh blood groups inherited

Answer 26

As a triplet

Question 27

What will agglutinate CcDe

Answer 27

anti-C, anti-c, anti-D and anti-e

Question 28

What will agglutinate cdE

Answer 28

anti-c, anti-E

Question 29

Which antigen is the most important in Rh, and why

Answer 29

D antigen | 80% of people without the D antigen will develop anti-D if exposed to it

Question 30

How may phenotype CcDEe be inherited

Answer 30

- CDe/ cDE - CDe/cdE - cDE/ Cde - CDE/cde

Question 31

What determines rhesus positive/ negative

Answer 31

Presence or absence of D antigen

Question 32

How is phenotype Ccde inherited

Answer 32

Cde/cde

Question 33

How is phenotype cde inherited

Answer 33

cde/cde

Question 34

Is it more common to be rhesus positive or negative

Answer 34

Positive

Question 35

Which pregnancy will haemolytic disease of the foetus and newborn affect

Answer 35

Second child

Question 36

How does haemolytic disease of the foetus and newborn come about?

Answer 36

- Rhesus (D) negative mother carries rhesus (D) positive baby - Immune system is sensitised to D antigen - Second rhesus (D) positive child-- there is now anti-D antibody which is stimulated, crosses placenta and destroys foetal red cells

Question 37

How is haemolytic disease of the foetus and newborn now managed

Answer 37

All rhesus (D) negative mothers get prophylactic anti- D in first pregnancy

Question 38

Can you give Rh(D) negative donor to a Rh (D) positive patient?

Answer 38

Yes

Question 39

What is removed in a red cell transfusion

Answer 39

Unit with the most plasma is removed

Question 40

What is removed in a red cells in additive solution

Answer 40

Unit with most plasma, white cells and platelets removed

Question 41

When may a red cell transfusion be required

Answer 41

- Blood loss - Bone marrow failure - Haemolysis - Inherited Hb disorders

Question 42

Should you do a red blood transfusion if anaemia is present due to iron/ B12 or folate deficiency?

Answer 42

Should be avoided if poss- instead give haematinic replacement therapy

Question 43

What are the potential risks of giving blood

Answer 43

- infection - alloimmunisation - incompatable transfusion - circulatory overload - iron overload

Question 44

Why is an indirect antiglobulin test done

Answer 44

To screen for atypical antibodies in patients plasma

Question 45

How is an indirect antiglobulin test carried out?

Answer 45

- Patients plasma mixed with group O cells expressing all the common blood group antigens - If antibody present, will bind to antigens on detector cells

Question 46

What must be monitored during a transfusion

Answer 46

Pulse, BP, temp

Question 47

What are the symptoms of a possible transfusion reaction

Answer 47

Restless, flushing, anxiety, abdo pain, nausea and diarrhoea, pain at venopuncture site

Question 48

What are the signs of transfusion reaction

Answer 48

Fever, hypotension, haemoglobinguria | Rapid temp spike >40 degrees

Question 49

How do you manage a possible transfusion reaction

Answer 49

Stop transfusion Maintain venous access with saline Commence resus

Question 50

Most common reason for incompatability

Answer 50

Patient wrongly identifed

Question 51

When do symptoms of delayed haemolytic transfusion reaction occur

Answer 51

7-10 days post transfusion

Question 52

Why does delayed haemolytic transfusion reaction occur

Answer 52

Failure of Hb to rise