Immunoglobulins

Question 1

What is the largest antibody?

Answer 1

IgM (massive!!) pentameter

Question 2

Antibody involved in type 1 hypersensitivity reactions

Answer 2

IgE

Question 3

Antibody in type 2 hypersensitivity reaction

Answer 3

IgG IgM

Question 4

Rhesus D immunoglobin treatment uses which antibody?

Answer 4

IgG

Question 5

What is rhesus isoimmunisation?

Answer 5

Rhesus negative mothers blood is sensitised to rhesus positive fetus blood producing IgG antibodies against RhD which can cross the placenta and cause anaemia/fetal haemolytic disease of the newborn/fetal death

Question 6

How does Rhesus D Immunoglobin treatment work?

Answer 6

IgG antibodies bind to the RhD positive fetal blood preventing maternal immune response in RHD negative mother

Question 7

By how much does anti-D reduce risk of alloimmunisation?

Answer 7

from 16% to <0.1%

Question 8

When is anti-D given in non-sensitised mothers antenatally?

Answer 8

single dose at 28 weeks

or two doses between 28-34weeks

Question 9

When is anti-D given to non-sensitised mothers postnatally?

Answer 9

Cord blood is tested
If fetus is rhesus positive: Mother should be given 500 units anti-D within 72 hours
Maternal blood should be tested for fetal maternal haemorrhage and additional anti-D given accordingly

Question 10

When should anti-D be given if there is a potentially sensitising event?

Answer 10

within 72 hours
Between 12-20 weeks, 250iu, fetal maternal haemorrhage testing is not required
After 20 weeks, 500iu, fetal maternal haemorrhage testing is required

Question 11

When should anti-D be given if the pregnancy is less than 12 weeks?

Answer 11

In Rhesus negative patients who have ectopic pregnancy, medical termination, molar pregnancy, heavy bleeding. fetal maternal haemorrhage testing is not required