A deficiency of blood cells of all lineages (but generally excludes lymphocytes) - not a diagnosis, and does not always mean bone marrow failure or malignancy
Aetiology
Reduced production - bone marrow failure
Inherited syndromes - very rare
Characterised by impaired haeopoiesis, congenital abnormalities and cancer predisposition
Arise due to defects in DNA repair/ribosomes/telomeres
Example: patients with Fanconi’s anaemia are unable to correct inter-strand cross-links (DNA damage)
Acquired
Primary - no obvious cause, usually stem cell defect
Myelodysplastic syndromes - increased apoptosis of progenitor and mature cells, propensity for evolution into AML
Acute leukaemia (WCC can be variable) - proliferation of abnormal cells from LSC, failure to differentiate into mature or normal cells, prevent normal HSC development
Secondary
Drug induced e.g. chemotherapy, alcohol, azathioprine, metotrexate, chlorampenicol - causes aplasia
B12/folate deficiency - nuclear maturation can affect all lineages
Pancytopenia can be caused by increased splenic pool or increased destruction that exceeds bone marrow capacity, usually associated with a significantly enlarged spleen
Causes of hypersplenism:
Splenic congestion e.g. portal hypertension
Systemic diseases e.g. rheumatoid arthritis
Haematological diseases e.g. splenic lymphoma
Pathophysology
Marrow cellularity in pancytopenia
Variable depending on the cause
Hypocellular in aplasic anaemia
Hypercellular in myelodysplastic syndromes, B12/folate deficiency, hypersplenism
Clinical features
Anaemia - fatigue, shortness of breath, cardiovascular compromise
Neutropenia - increased severity and duration of infections, opportunistic infections