Aplastic Anaemia

Question 1

Definition

Answer 1

Characterised by diminished haematopoietic precursors in the bone marrow and deficiency of all blood cell elements (pancytopaenia)

Question 2

Aetiology (idiopathic)

Answer 2

Idiopathic (> 40%)

o May be due to destruction or suppression of stem cells via autoimmune mechanisms

Question 3

Aetiology (acquired)

Answer 3

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

Question 4

Aetiology (inherited)

Answer 4

o Fanconi’s anaemia

o Dyskeratosis congenita (a rare, progressive bone marrow failure syndrome)

Question 5

Epidemiology

Answer 5

• Annual incidence: 2-4/1,000,000

* Slightly more common in males

Question 6

Onset

Answer 6

Can be both slow-onset (months) or rapid-onset (days)

Question 7

Presenting symptoms (anaemia)

Answer 7

o Tiredness
o Lethargy
o Dyspnoea

Question 8

Presenting symptoms (thrombocytopaenia)

Answer 8

o Easy bruising
o Bleeding gums
o Epistaxis

Question 9

Presenting symptoms (leukopaenia)

Answer 9

o Increased frequency and severity of infections

Question 10

Signs on physical examination

Answer 10

• 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 11

Investigations (bloods)

Answer 11

o FBC

• Low Hb
• Low platelets
• Low WCC
• Normal MCV
• Low or absent reticulocytes

Question 12

Investigations (other)

Answer 12

• 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