Autoimmune disease

Question 1

Where are the immunological privileged sites in the body

Answer 1

Brain, eye, testis, uterus

Question 2

Describe autoimmune haemolytic anaemi if autoab is IgG and IgM

Answer 2

IgG: will coat RBC. RBC taken up by macrophages via Fc receptor and transported to spleen where they are destroyed

IgM: RBCs lysed by MAC formation

Question 3

Describe what happens in haemolytic disease in newborn

Answer 3

1. Rh+ father
2. Rh- mother
3. First baby is Rh+
4. Rh+ from foetus enters Mum’s blood, Mum produces anti-Rh+ antibodies
5. In second pregnancy, second baby is Rh+
6. Anti-Rh+ antibodies can cross placenta & attack foetus
7. Coat foetal RBC –> taken up by macrophages in foetal spleen –> destroyed

Question 4

Symptoms of haemolytic disease in newborn

Answer 4

Mild jaundice
Hydrop fetalis (generalised oedema)
Anaemia and increased bilirubin due to RBC destruction
Hepatosplenomegaly

Question 5

How to prevent haemolytic disease in newborn

Answer 5

Give mother anti-RhD during first pregnancy to mop any foetal RhD+ cells in her circulation

Question 6

Describe Farmers Lung

Answer 6

Type 3 hypersensitivity.

Hypersensitivity pneumonitis from inhalation of biological dusts.

IgG combines with inhaled allergen to form immune complexes in the walls of lung alveoli.

Fluid, protein, inflammatory cells accumulate in alveoli.

Question 7

Describe SLE

Answer 7

Type 3 hypersensitivity.

Antibody response to nuclear and cytoplasmic antigens and the formation of immune complexes which deposit in tissues.

Can affect any organ.