Paediatric haematology Flashcards
Children are more likely than adults to respond to infections with _____?
Children are more likely than adults to respond to infections with lymphocytosis
________ are also common because of the frequent encounters with new microbial antigens
‘Reactive’ lymphocytes are also common because of the frequent encounters with new microbial antigens
The neonate will have higher percentage of haemoglobin __ than at any other time of life so disorders of ____ _____ genes are much less likely to be manifest
The neonate will have higher percentage of haemoglobin F than at any other time of life so disorders of beta globin genes are much less likely to be manifest
Polycythaemia (hb even higher than for age) in the fetus or neonate can result from ___?
Twin-to-twin transfusion
Intrauterine hypoxia
Placental insufficiency
Anaemia in the fetus or neonate can result from ___?
Twin-to-twin transfusion
Fetal-to-maternal transfusion
Parvovirus infection (virus not cleared by immature immune system)
Haemorrhage from the cord or placenta
what is transient abnormal myelopoiesis or TAM ?
Congenital leukaemia
This specific type of neonatal leukaemia
is particularly common in Down’s syndrome
differs greatly from leukaemia in older infants or children
The leukaemia is myeloid with major involvement of the megakaryocyte lineage - platelets
The most remarkable feature is that it usually remits spontaneously
in which demographic do the following present? what is the pheneotype for the chains:
HbA
HbA2
HbF
HbA
α2β2 - Late fetus, infant, child and adult
HbA2
α2δ2 - Infant, child and adult
HbF - α2γ2
Fetus and infant
describe the globin genes responsible for beta and alpha globin?
chromosome 11 - responsible for beta globin gene
beta, delta and 3 region
chromosome 16 - alpha globin gene.
has 2 alpha regions and theta
What is sickle cell disease?
Hypoxia causes sickling of rbc’s
Red cells elongate to pass through capillary bed to post-capillary venule
adhere to endothelium
Can cause vascular obstruction* -> small vessel disease
*venule obstruction and reetrograde capillary obstruction
what is the genotype for sickle cell trait?
On the beta globin gene cluster
ββS — Sickle cell trait, ‘AS’
βSβS—Sickle cell anaemia, ‘SS’
βSβc—Sickle cell/haemoglobin C disease
βSβThal— Sickle cell/beta thalassaemia
Sickle cell anaemia is not clinically manifest at birth
Why?
Clinical features become manifest as gamma chain production and haemoglobin F synthesis decrease and betaS and haemoglobin S production increase
how is sickle cell now idagnosed at birth?
guthrie test
Sickle cell anaemia in the infant and child differs from the same disease in the adult
Why is that?
- The distribution of red bone marrow (susceptible to infarction) differs—they get hand/foot involvement/syndrome
this does not manifest in toddlers or above
- The infant still has a functioning spleen—splenic sequestration can occur : presents ACUTE risk of death -> doesnt happen as they get older
- The infant has an immature immune system and has not developed immunity to pneumococcus or parvovirus
what kind of crises aree sickle sufferers susceptible to and in what %?
Painful crises, about 40% per year
Acute chest syndrome 34% -> decreases as age increases
Stroke, cumulative incidence 4-8%
hand-foot syndrome - neonates
As the risk of splenic ____ wanes the risk of ____ waxes
As the risk of splenic sequestration wanes the risk of hyposplenism waxes
meaning as they have less risk of dying from sequestration, their risk of dying from infection increases.
