Haematology - Paediatric haematology Flashcards
How should congenital leukaemia in Down’s syndrome be managed?
It will resolve spontaneously in first few months of life
although does relapse In about 25%
Why may there be Howel-Jolly bodies on the blood film in sickle cell disease?
They are produced when there is splenic infarction (hyposplenism)
If not identified in a Guthrie spot, at what age does sickle cell disease tend to present?
3-6 months,
coincides with
reduction in HbF & gamma chin production
increase in HbS production
In what age group might the hand-foot syndrome of sickle cell disease present?
<2 years
Infants with SCD may develop hand-foot syndrome, a dactylitis presenting as exquisite pain and soft tissue swelling of the dorsum of the hands and feet.
Why is there no risk of splenic sequestration in sickle cell disease once Howel-Jolly bodies have been identified on blood film?
Once there has been a splenic infarction (which will cause Howel Jolly bodies) you will get hyposplenism but there is no risk of sequestration
Recall 2 drugs that are required lifelong in all sickle cell disease patients?
Folic acid
Penicillin (for protection against encapsulated bacteria because of hyposplenism)
In sickle cell disease, when is the highest risk of stroke?
In childhood (actually less common in adults with sickle cell)
What is the main risk of blood transfusions in treating thalassaemia?
Iron overload
Recall some inherited causes of haemolytic anaemia
Spherocytosis
Elliptocytosis
PKU deficiency
G6PD deficiency
Sickle cell
What is the most common cause of acquired haemolytic anaemia in children?
E coli causing haemolytic uraemic syndrome
Which inherited defect of coagulation often presents with mucosal bleeding?
Von willebrand disease
How can you test for von willebrand disease?
Factor VIII assay
VWF ristocetin cofactor activity assay (VWF:RCo),
What is the treatment for von willebrand disease?
Low purity factor VIII
In which haemoglobinopathy is there benefit to carotid doppler monitoring?
Sickle cell
Do doppler monitoring alongside exchange transfusion if there is turbulent carotid flow
genotype of SCA
HbSS
genotype of SCTrait
HbAS - asymptomatic except under stress (cold, exercise)
give 5 features of haemolysis in SCA
anaemia 60-80g/L
splenomegaly
folate def
gallstones
aplastic crises (parvo B19)
give 7 features of a vaso-occlusive “sickled” crisis
stroke
crises (splenic sequestration, chest pain)
gallstones
retinopathy
dactylitis
mesenteric ischaemia
priapism
what complications of SCA are more common in childhood vs adulthood
childhood = stroke! splenomegaly, dactylitis adulthood = hyposplenism, CKD, retinopathy, pulmonary hypertension
what cells on blood film of sickle cell anaemia
sickle cells
target cells
3 tests to diagnose sickle cell anaemia
Guthrie - neonate
sickle solubility test
Hb electrophoresis
treatment of an acute sickle cell crisis?
opioid analgesia
blood/exchange transfusion
give a drug that may be of benefit in SCA
hydorxycarbamide
explain the pathophysiology of beta thalassemia
point mutation leading to decreased beta chain synthesis and excess alpha chains (HbA2)
(spectrum of disease)
treatment of beta thal
minor and some intermediate may not require
otherwise - blood transfusions with iron chelation to stop overload, plus folic acid
explain the pathophysiology of alpha thalassemia
reduced alpha chain synthesis, excess beta chains
types of alpha thal
4 alpha genes in total, severity depend son how many deleted
trait = 1/2 deleted = asymptomatic, mild
HbH disease = 3 deleted
hydros foetalis = 4 deleted = incompatible w life
3 phenotypical traits of beta thal
skull bossing
maxillary hypertrophy
hairs on end skull x ray
inheritance of both thalassemia and SCA
all autosomal recessive
which thalassemia type isn’t compatible with life
Hb Bart’s hydrops fetalis, also known as alpha thalassemia major, is the most severe form of alpha thalassemia. The term hydrops fetalis describes the accumulation of large amounts of fluid (edema) in the tissues and organs of a developing fetus.
what causes the anaemia in SCA
the anaemia in sickle cell anaemia is NOT totally due to haemolysis alone
HbS is a low-affinity Hb meaning that it more readily releases O2 to tissues, so the EPO-drive is lower which results in anaemia
what factor is affected in hameophilia A
8
what factor is affected in haemophilia B
factor 9
which haemophillia is more common
Haemophilia A is 4x more common than B
