Paediatric haematology

Question 1

What is the difference between child and adult red blood cells?

Answer 1

Site of haematopoeisis
Haemoglobin switching from gamma chain haemoglobin → beta chain haemoglobin
Larger red blood cells
higher haematocrit -

Question 2

What is the difference between child and adult white blood cells?

Answer 2

Higher lymphocyte counts

Immune system is a work in progress in a child

Question 3

How does the immune system work in a child?

Answer 3

IgG crosses the placenta
breast milk has IgA, IgD, IgE, IgG, IgM → passive immunity
start producing antibodies at 2-3/12
can make satisfactory immune responses by 6/12

Question 4

What is the difference between child and adult platelets?

Answer 4

Reach adult numbers by 18/40 gestation
Initially larger, by birth slim down to adult size
Functionally different at birth
less responsive to certain agonists
more responsive to vWF

Question 5

What is the difference between child and adult coagulation proteins?

Answer 5

Coagulation proteins do not cross placenta effectively
Only fibrinogen, FV, FVIII, FXIII are normal at birth
Most haemostatic parameters reach adult values by 6 months

Question 6

What coagulation proteins are vitamin dependent?

Answer 6

Factor 2
Factor 7
Factor 9
Factor 10
protein C
protein S

Question 7

What is caused by a deficiency in Vit K in a newborn?

Answer 7

Haemorrhagic disease of the newborn

Question 8

How is haemorrhagic disease of the newborn avoided?

Answer 8

Prevented by routine neonatal vitamin K

Question 9

How can deficiency in Vit K in a newborn be exacerbated?

Answer 9

If on anti-convulsants

mother needs oral vitamin K

Question 10

What are the causes of congenital anaemias that happen in childhood?

Answer 10

Haemoglobin synthesis problem = haemoglobinopathy
Bone marrow failure syndromes
Bone marrow infiltration
Peripheral destruction
Blood loss

Question 11

What are the haemoglobinopathy that can happen in childhood and how can they be picked up before pregnancy?

Answer 11

thalassaemia
sickle cell disease

antenatal screening

Question 12

What are the causes of peripheral destruction that happen in childhood?

Answer 12

Rh/ABO or other incompatibility
Membrane defect: hereditary spherocytosis
Enzyme defect: G6PD deficiency, PK deficiency
Infection

Question 13

What is hereditary spherocytosis?

Answer 13

disorder is caused by mutations in genes relating to membrane proteins that allow for the erythrocytes to change shape
become spherical
haemoglobin squashed into a compact shape in the cell
brittle cells
autosomal dominant

Question 14

What are examples of blood loss when babies are born?

Answer 14

Twin to twin transfusion - one baby has bled into the other baby
Fetomaternal haemorrhage

Question 15

What are causes of acquired anaemia in childhood?

Answer 15

Nutritional deficiency: iron, B12, folate
Bone marrow failure
Bone marrow infiltration
Peripheral destruction: haemolysis
Blood loss

Question 16

What are the causes of congenital bleeding and bruising?

Answer 16

Platelet problem
Clotting factor problem
Connective tissue disorder

Question 17

What are the causes of acquired bleeding and bruising?

Answer 17

Trauma
Tumour
Infection: meningococcus, HIV
Immune disorder: immune thrombocytopenia, TTP, SLE, ALPS
Bone marrow failure
Drug related

Question 18

What the typical presentation of a child with anaemia that has acute lymphoblastic leukemia?

Answer 18

lots of nose bleeds
bruises
pale
coughs/colds