Aplastic anemia occurs when your bone marrow doesn't make enough red and white blood cells, and platelets.

Characterised by pancytopenia and a hypoplastic bone marrow, there are no other abnormal cells in the peripheral blood or bone marrow - it is usually acquired but could rarely be genetic

Peak incidence of acquired = 30 years old

Causes

• idiopathic
• congenital (rare): Fanconi anaemia (most common inherited cause, AR), dyskeratosis congenita
• drugs: cytotoxics, chloramphenicol, sulphonamides, phenytoin, gold
• toxins: benzene, glue sniffing
• infections: parvovirus, hepatitis, EBV
• ionising radiation
• miscellaenous e.g. pregnancy

Pathophysiology

• Occurs due to a reduction in the number of pluripotent stem cells - with a fault in those remaining or an immune reaction against them so they cant repopulate the bone marrow
• Failure of once cell line may occur = isolated deficiencies such as absence of red cell precursors in pure red cell aplasia
• Evolution to myelodysplasia, paroxysmal nocturnal haemoglobinuria (PNH) or acute myeloid leu- kaemia occurs in some cases, probably owing to the emergence of an abnormal clone of haemopoietic cells.

Features

• bleeding (brusing, minimal trauma in the mouth)