Paeds- Haematology Flashcards
describe the haemologlobin levels required for a diagnosis of anaemia in:
- neonates
- 1 month-12 months
- 1 year- 12 years
Neonate: Hb <140g/L
1month-12months: Hb<100g/L
1year-12years: Hb<110g/L
what 3 things can cause anaemia?
- impaired red cell production
- increased red cell destruction (haemolysis)
- blood loss
causes of impaired red cell production
- red cell aplasia- parvovirus B19 infection, fanconi anaemia, aplastic anaemia
- ineffective erythropoiesis- iron deficiency, folic acid deficiency, chronic inflammation
causes of haemolysis
- hereditary spherocytosis
- G6PD deficiency
- thalassaemia, sickle cell
what can cause severe anaemia at birth?
haemolytic disease of the foetus (Rhesus disease)
what antibodies are present in Rhesus?
- anti-D
- anti-A/ anti B
- anti-Kell
how is Rhesus diagnosed?
positive direct anti-globulin test= Coombs test
how does haemolytic disease of the newborn present clinically?
- pallor
- hepatosplenomegaly
- oedema
- ascites
- petechiae
what is Fanconi anaemia?
- most common inherited form on aplastic anaemia
- autosomal recessive
- mutations in FANC genes
clinical presentation of fanconi anaemia
congenital abnormalities- short stature etc
bone marrow failure
causes of iron deficiency anaemia
- inadequate intake
- malabsorption
- blood loss
how is iron deficiency anaemia diagnosed?
microcytic, hypochromic, low-normal reticulocytes
low ferritin and serum iron
what is haemolysis?
increased red blood cell turnover
how does haemolytic anaemia present clinically?
- jaundice
- pallor
- neonatal ascites
- anaemia/ failure to thrive
- hepato/splenomegaly
- gall stones
- aplastic crisis
- thromboembolism
how is a patient with haemolytic anaemia investigated?
- raised reticulocyte count
- unconjugated bilirubinaemia and increased urinary urobillinogen
- coombs test
how is G6PD deficiency inherited?
x-linked recessive
how does G6PD deficiency present clinically?
neonatal jaundice
intermittent episodes of acute intravascular haemolysis
fever, malaise, dark urine, abdo pain
how is G6PD deficiency diagnosed?
- between episodes- normal blood picture !
- measure G6PD activity in red blood cells- measure during and after crisis
describe the inheritance pattern of hereditary spherocytosis
- autosomal dominant
- 25% of cases- no family history, caused by new mutation
what is hereditary spherocytosis?
genetic condition in which mutations occur in the genes coding for proteins of the red cell membrane
red cells lose part of membrane when passing through spleen= reduction in surface-to-volume ratio
leads to spheriodal cells
clinical features of hereditary spherocytosis
- jaundice (intermittent)
- anaemia
- splenomegaly
- aplastic crisis
- gallstones
can be asymptomatic
if a patient presented with suspected hereditary spherocytosis, what investigations would be done?
- blood film is diagnostic
- do coombs test to rule out autoimmune cause
how is hereditary spherocytosis managed?
- oral folic acid
- splenectomy if severe
- blood transfusions
- cholecystectomy
describe the mutation pattern of sickle cell anaemia
autosomal recessive inheritance on chromosome 11 of abnormal haemoglobin gene
HbS forms- due to point mutation of codon 6 in B globulin gene- changes glutamine to valine
what are the 3 types of sickle cell anaemia?
HbSS- sickle cell anaemia (HbS from both parents)
HbSC- sickle cell disease (HbS from one parent, HbC from another)
sickle-B- thalassaemia (HbS from one parent, B-thalassaemia from the other)
describe some complications of sickle cell anaemia
- anaemia
- haemolytic/ aplastic crises
- infection/ sepsis
- vaso-occlusive crises
- splenomegaly
- priapism
describe the long-term problems of sickle cell anaemia
- Stroke - 1in10 have a stroke
- Short stature + delayed puberty- Cardiomegaly/Heart Failure - from chronic anaemia
- Psychosocial problems - due to time off school
- Pigment gallstones
- Renal dysfunction
what is thalassaemia?
reduced globin chain synthesis
what is beta thalassaemia?
defects in B-chains in adult HbA haemoglobin
autosomal recessive HBB gene on chromosome 11
resulting in excess of alpha chains
how do RBC appear on a blood film in beta thalassaemia?
microcytic and hypochromic
describe the presentation of minor (heterozygote/ carrier) beta thalassaemia?
asymptomatic
mild anaemia, low MCV
describe the presentation of major beta thalassaemia?
- progressive severe anaemia
- jaundice
- splenomegaly
- failure to thrive
- skeletal deformity
- delayed puberty
- death in early teens
how is beta thalassaemia diagnosed?
- MCH + MCV reduction
- raised RBC
- raised HBA2
- skull x ray- hair-on-end sign
how is beta thalassaemia differentiated from iron deficiency anaemia?
normal serum ferritin
how is beta thalassaemia managed?
- regular blood transfusions
- iron chelation
- bone marrow transplant
- long term folic acid
what is thrombocytopenia?
low platelet count
what is ITP?
immune/idiopathic thrombocytopenic purpura
destruction of platelets by IgG autoantibodies
when does ITP typically present?
young children post-viral infection
most present 2-10 years
recover spontaneously
how does ITP present acutely?
- petechiae on dependent extremities
- purpura/ superficial bruising
- epitaxis
how does chronic ITP present?
- platelet count remains low for a number of months
- associated bleeding- GI, nose, intracranial
how is ITP diagnosed?
diagnosis of exclusion- only low platelets ! (allows you to differentiate from other conditions)
how is ITP treated?
rare to need treatment
- can give prednisolone
- platelet transfusion if necessary
what is Von Willebrand’s disease?
bleeding disorder caused by an abnormality of the VWF- a carrier protein for factor VIII
3 tyes- ranging in severity
describe type 1 Von Willebrand’s disease
autosomal dominant
mild
describe type 2 Von Willebrand’s disease
autosomal dominant
moderate
describe type 3 Von Willebrand’s disease
autosomal recessive
severe
clinical features of Von Willebrand’s disease
bruising
prolonged bleeding (e.g. after surgery)
mucosal bleeding
what investigations would be performed in a patient with suspected Von Willebrand’s disease?
- clotting screen abnormal
- APTT increased
- VFW and factor VIII decreased
how is Von Willebrand’s disease treated?
Tranexamic acid
what is the difference between Haemophilia A and B?
deficiency of factor VIII (haemophilia A)
factor IX deficiency= haemophilia B
how does Haemophilia present in neonates?
- Cephalohaematoma
- iatrogenic bleeding
- umbilical cord bleeding
how does Haemophilia present in early childhood?
- easy bruising
- mouth bleeds
- spontaneous joint/ muscle bleeds
how are type A and B Haemophilia treated?
factor VIII/IX respectively
