Immunology of Pregnancy

Question 1

What is fetal growth restriction associated with?

Answer 1

Increased risk of cardiovascular disease, diabetes and stroke

Question 2

What is pre-eclampsia?

Answer 2

Hypertension that develops during pregnancy

Proteinuria

Oedema

Question 3

When is pre-eclampsia most common?

Answer 3

1. First pregnancies
   Risk falls with subsequent pregnancies unless change of partner
2. Oocyte donation

Question 4

What are the two sites of interaction between maternal immune cells and the trophoblast?

Answer 4

1. Maternal blood in contact with syncytium

2. Invading trophoblast in contact with decidua

Question 5

What does systemic immunity refer to?

Answer 5

Immunity between maternal blood in contact with syncytium

Question 6

What does local immunity refer to?

Answer 6

Immunity against invading trophoblast in the decidua

Question 7

What is the pathogenesis of pre-eclampsia?

Answer 7

1. Extravillous trophoblast fails to invade decidua properly
2. Inadequate conversion of the spiral arteries
3. Altered blood supply to placenta
4. Placenta stress
5. Maternal systemic endothelial disease

Question 8

What is the role of the decidua?

Answer 8

Allow the trophoblast to invade adequately and protect the underlying uterine tissue

Question 9

What occurs where there is no decidua?

Answer 9

1. Trophoblast invades through caesarian scar
2. Ectopic pregnancies are dangerous
3. Placenta acreta/percreta

Question 10

Where is HLA-G expressed?

Answer 10

Trophoblast only

Question 11

Which HLA varies from pregnancy to pregnancy?

Answer 11

HLA-C

Question 12

Which leukocytes occur in the decidua?

Answer 12

1. CD56bright natural killer cells
2. CD14+ macrophages
3. Dendritic cells
4. T cells and B cells

Question 13

When do NK cell levels increase?

Answer 13

Secretory phase of cycle due to progesterone

Remain high throughout pregnancy

Question 14

How are NK cells regulated?

Answer 14

1. Monitor MHC levels on cells
2. Activated by stress and viral ligands
3. Integrate activating and inhibitory signals

Question 15

What are the three main types of receptor used by NK cells to monitor levels of HLA?

Answer 15

1. KIR
2. NKG2A/CD94
3. LILRB1

Question 16

What does KIR recognise?

Answer 16

HLA-C

Question 17

What does NKG2A/CD94 recognise?

Answer 17

HLA-E

Question 18

What does LILRB1 recognise?

Answer 18

HLA-G

Question 19

What determines KIR recognition of HLA-C?

Answer 19

C1 or C2 epitope

Question 20

Which chromosome carries the KIR locus?

Answer 20

Chromosome 19

Question 21

Which chromosome carries the HLA-C locus?

Answer 21

Chromosome 6

Question 22

Which KIR haplotype is protective?

Answer 22

KIR B

Even when fetus has C2

Question 23

Which KIR haplotype is at risk?

Answer 23

KIRAA with C2

Question 24

What combination of KIR and HLA increases the risk of pre-eclampsia?

Answer 24

KIRAA with C2

Question 25

How does the maternal immune system change in pregnancy?

Answer 25

1. Responses to viruses are altered (may be more severe with chickenpox and flu)
2. Rheumatoid arthritis and MS symptoms improve
3. Ankylosing spondylitis and lupus get worse

Question 26

What are the two routes for infection to the fetus?

Answer 26

1. Infection from maternal blood

2. Through the decidua

Question 27

What are Hofbauer cells?

Answer 27

Fetal macrophages