Pancytopenia Flashcards
What is pancytopenia?
Pancytopenia is a deficiency of blood cells of all lineages
This is not a diagnosis, but reflects a diagnosis
What are the 2 main mechanisms of pancytopenia?
Reduced cell production
Increased cell destruction
What is the main cause of reduced cell production?
Bone marrow failure
What are the main forms of bone marrow failure?
Primary acquired bone marrow failure
Secondary acquired bone marrow failure
Inherited bone marrow failure
What are some causes of primary acquired bone marrow failure?
- Idiopathic aplastic anaemia
- Myelodysplastic syndromes
- Acute leukaemia
What is idiopathic aplastic anaemia?
Idiopathic aplastic anaemia is a condition in which auto-reactive T-cells produce IFN-y and TNF-a against haemopoietic stem cells and common myeloid progenitors
This prevents production of erythrocytes, platelets and granulocytes
What are myelodysplastic syndromes?
Myelodysplastic syndromes are clonal haemopoietic stem cell disorders characterised by dysplasia (Disordered development) or unique genetic abnormalities of the bone marrow
This involves increased apoptosis of progenitor and mature cells (Ineffective haemopoiesis)
What is a possible risk of myelodysplastic syndromes?
Evolution into AML
How can acute leukaemia cause pancytopenia?
Leukaemic stem cells can cause proliferation of abnormal cells (Blasts), which fail to differentiate or mature into normal cells
This also prevents normal haemopoietic stem cell/progenitor development by hijacking or altering the haemopoietic niche and marrow microenvironment (Pushes aside normal cells)
What are some causes of secondary acquired bone marrow failure?
- Drug induced
- B12/Folate deficiency (Nuclear maturation can affect all lineages)
- Infiltrative (Non-haemopoietic malignant infiltration, lymphoma)
- Viral (e.g. HIV)
- Storage diseases
What are some drugs that can cause secondary acquired bone marrow failure?
Chemotherapy
Alcohol
Azathioprine
Methotrexate
Chloramphenicol
What are inherited bone marrow failures?
These are disorders characterised by impaired haemopoiesis, congenital abnormalities and cancer predisposition
How do inherited bone marrow failures occur?
They arise due to defects in DNA repair, ribosomes and telomeres
What is an example of an inherited bone marrow failure?
Fanconi’s anaemia
What is Fanconi’s anaemia?
Fanconi’s anaemia is a rare inherited condition affecting the bone marrow, in which there is an inability to correct inter-strand cross-links in DNA (DNA damage)