Haematology 12 - Paediatric haematology

Question 1

How does a child’s response to infection differ to an adults (a v general answer)

Answer 1

Children respond with a lymphocytosis, reactive lymphoctosis much more common in children due to frequent encounters with new infections

Question 2

Why are children more predisposed to nutrition deficiencies?

Answer 2

Rapid growth e.g. iron deficiency, folate deficiency

Question 3

Which blood parameters are high in neonates?

Answer 3

WCC, neutrophils, lymphocytes, Hb and MCV

Question 4

Which enzyme level in RBCs differs in neonates vs adults?

Answer 4

G6PD concentration is 50% higher in neonates

Question 5

3 causes of polycythaemia in a foetus/neonate?

Answer 5

1. Twin to twin transfusion syndrome
2. Intrauterine hypoxia
3. Placental insufficiency

Question 6

4 causes of anaemia in foetus/neonate

Answer 6

1. Twin to twin transfusion syndrome
2. Foetal-maternal transfusion syndrome
3. Placental or cord bleeding
4. Parvovirus infection

Question 7

Which anticoagulant drug should not be used in pregnant mother? What effects could it have on the baby?

Answer 7

Warfarin –> foetal haemorrhage

Question 8

1 way in which the intrauterine environment can have an effect later in childhood?

Answer 8

The first mutation in leukaemia often occurs in utero

Question 9

Congenital leukaemia - in which particularly pt group is this common?

How does it differ to ALL?

Answer 9

Also known as Transient abnormal myelopoiesis (TAM), common in Down’s syndrome.

TAM is a myeloid leukaemia with major involvement of the megakaryocyte lineage. The disease tends to spontaneously remit in the first 2 months and then recurrs 1-2 years later in about 25%

Question 10

Difference in pathophysiology of thalassaemia and a haemaglobinopathy

Answer 10

Thalassaemia is a defect in the rate of synthesis of at least 1 globin chain

Haemaglobinopathy = structurally abnormal Hb

Question 11

Which chromosomes are the alpha and beta chains on, respectively?

Answer 11

Alpha = chr16
beta= chr11

Question 12

How many alpha genes are there?

Answer 12

2 genes per chromosome

Question 13

What is usually seen on blood film in hyposplenism?

Answer 13

Howell-Jolly bodies

Question 14

How does SCA lead to crises?

Answer 14

Sickled cells become adherent to endothelium –> obstruction occurs and retrograde capillary obstruction

Question 15

ββS - what is this

Answer 15

Sickle cell trait

Question 16

βSβS - what is this

Answer 16

Sickle cell anaemia

Question 17

βSβc - what is this?

Answer 17

Sickle cell/haemaglobin C disease - milder than SCA!

Question 18

βSβThal - what is this?

Answer 18

Sickle cell/ beta thalassaemia

Question 19

What does the severity of

βSβThal depend on?

Answer 19

If it is a beta0 gene (no beta globin production)

If it is a beta + gene (little beta globin production)

Question 20

When does SCA manifest?

Answer 20

Around 6 months as there is a decrease in HbF and increase in HbS production

Question 21

What antenatal screening is done for sickle cell?

Answer 21

Family origins questionnaire

Question 22

what is hand-foot syndrome? why does it occur in first few years of life?

Answer 22

Swelling and pain of hands and feet due to red marrow infarction

Different distribution of BM in adults vs children. In adults, BM only in axial skeleton but in children in axial skeleton + extends to bones of hands and feet

Question 23

The two types of BM

Answer 23

Yellow bone marrow (largely fat) and red bone marrow (produces haematopoietic precursors and is metabolic thus prone to infarction)

Question 24

What is splenic sequestration? When does it tend to occur?

Answer 24

acute pooling of a large % of blood in spleen –> severe anaemia + splenomegaly

Young children

Question 25

Why does splenic sequestration not occur in older children or adults?

Answer 25

Spleen is small and fibrotic from recurrent infarction thus more likely to have complications from hyposplenism

Question 26

Most common cause of stroke in childhood

Answer 26

SCA

Question 27

When does hand-foot-syndrome tend to occur?

Answer 27

first 2 years of life

Question 28

2 particular infections to worry about in SCA?

Answer 28

Pneumococcus parvovirus

Question 29

Infarction in the ribs and lungs in SCA patients

Answer 29

Acute chest syndrome

Question 30

Consequence of first exposure to parvovirus B19 in SCA child?

Answer 30

Red cell aplasia

Question 31

Why is folic acid requirement higher in SCD? 3 reasons

Answer 31

1. Hyperplastic erythropoiesis
2. Growth spurts
3. Red cell lifespan is shortened so anaemia can rapidly worsen

Question 32

Siblings with SCA present simultaneously with severe anaemia and a low reticulocyte count - likely diagnosis?

Answer 32

Parvovirus B19 infection

Question 33

Bthal Beta - what is this?

Answer 33

Beta thalassaemia trait

Question 34

Bthal Bthal - what is this?

Answer 34

Beta thalassaemia major

Question 35

Bthal + Bthal + what is this?

Answer 35

Beta thalassaemia intermedia - homozygous but + forms of beta globin instead of 0 forms

Question 36

What’s the difference between thalassemia major and minor?

Answer 36

Major requires lifelong transfusions for survival, minor still symptomatic and anaemic but no transfusions required

Question 37

Clinical features of poorly treated thalassaemia

Answer 37

Anaemia –> heart failure, growth retardation
Erythropoietic drive –> hepatosplenomegaly, bone expansion
Iron overload –> heart failure, growth failure, hypogonadism

Question 38

7yo AC boy
Severe anemia
MCV upper limit of normal
Normal platelets
Irregularly contracted cell = Hb has precipitated into one part of the RBC
Some large cells = reticulocytes

Answer 38

G6PDD

Question 39

whAT ARE the two main causes of anaemia in SCA?

Answer 39

Haemolysis due to sickle shaped cells but also HbS has a lower affinity for O2 so releases O2 to cells more readily therefoer there is a lower EPO drive

Question 40

Autoimmune haemolytic anaemia is characterised by

Answer 40

Spherocytes and positive DAT

Question 41

Presentation of haemophilia A and B in young children

Answer 41

Bleeding when circumcised, haemarthroses when starting to walk, bruises, post-traumatic bleeding

Question 42

The bleeding time in vWD and haemophilia, respectively

Answer 42

vWD = prolonged
haemophilia = normal as no issue with primary plug formation

Question 43

Diagnosis of vWD

Answer 43

• Family history (mainly autosomal dominant)
  o Coagulation screen
  o Factor 8 assay
  o Platelet aggregation studies

Question 44

Treatment of vWD

Answer 44

Factor VIII concentrates

Question 45

Heparin and warfarin effect which coagulation pathways, respectively?

Answer 45

Heparin –> intrinsic prolonged

warfarin –> Extrinsic prolonged

Question 46

Treatment of autoimmune ITP

Answer 46

Observation, Steroids, high dose IVIG

Question 47

<1 YEARS OLD, IS ALL OR AML MORE COMMON?

Answer 47

AML more common < 1 e.g. TAM