Aplastic anaemia

Question 1

Define:

Answer 1

Rare stem cell disorder characterised by diminished haemopoetic precursors in the bone marrow and pancytopenia

Question 2

Aetiology/risk factors:

Answer 2

> 40% are idiopathic

Most = autoimmune triggered by drugs, viral infection or irradiation

o	Drugs (e.g. chloramphenicol, sulphonamides, methotrexate)
o	Chemicals (e.g. benzene, DDT)
o	Radiation
o	Viral infection (e.g. parvovirus B19)
o	Paroxysmal nocturnal haemoglobinuria

o Fanconi’s anaemia
o Dyskeratosis congenita (a rare, progressive bone marrow failure syndrome)

Question 3

Epidemiology:

Answer 3

• Annual incidence: 2-4/1,000,000

* Slightly more common in males

Question 4

Symptoms:

Answer 4

•	Can be both slow-onset (months) or rapid-onset (days)
•	Anaemia Symptoms:
o	Tiredness 
o	Lethargy 
o	Dyspnoea
•	Thrombocytopaenia Symptoms:
o	Easy bruising
o	Bleeding gums 
o	Epistaxis
•	Leukopaenia Symptoms:
o	Increased frequency and severity of infections

Question 5

Signs:

Answer 5

•	Anaemia Signs:
o	Pallor
•	Thrombocytopaenia Signs:
o	Petechiae
o	Bruises
•	Leukopaenia Signs:
o	Multiple bacterial and fungal infections 
o	No hepatomegaly, splenomegaly or lymphadenopathy

Question 6

Investigations:

Answer 6

•	Bloods
o	FBC
•	Low Hb
•	Low platelets 
•	Low WCC
•	Normal MCV 
•	Low or absent reticulocytes 
•	Blood Film
o	Exclude leukaemia (check for abnormal circulating white blood cells)
•	Bone Marrow Trephine Biopsy
•	Fanconi's Anaemia
o	Check for presence of increased chromosomal breakage in lymphocytes cultures in the presence of DNA cross-linking agents