Pancytopenia Flashcards
What is pancytopenia?
A deficiency of blood cells of all lineages
What cell types are generally included in pancytopenia? Which is excluded?
Erythrocytes, platelets and neutrophils / lymphocytes
What are the two broad causes of pancytopenia?
Reduced production of cells or increased destruction of cells
What is the general cause of reduced production of cells leading to pancytopenia?
Bone marrow failure
Inherited marrow failure syndromes arise due to defects in what?
DNA repair and ribosomes
What are the 3 main features of inherited marrow failure syndromes?
Cancer predisposition, congenital anomalies, impaired haemopoiesis
What is the main example of an inherited bone marrow failure syndrome?
Fanconi’s anaemia
What are some features of Fanconi’s anaemia?
Short stature, skin pigment abnormalities, endocrinopathies, CV/GI/renal/haematological abnormalities
What is the median age of onset of Fanconi’s anaemia?
7 years
What will happen to the cell size in Fanconi’s anaemia?
Macrocytic
Fanconi’s anaemia increases the risk of developing what cancer by more than 50% at 40 years?
Leukaemia
What are the 3 main groups of acquired primary bone marrow failure?
Idiopathic aplastic anaemia, myelodysplastic syndromes and acute leukaemia
What is idiopathic aplastic anaemia?
An autoimmune attack against haemopoietic stem cells
What happens in idiopathic aplastic anaemia?
Autoreactive T cells produce cytokines which damage the stem cells, particularly of the myeloid lineage
Describe what happens in myelodysplastic syndromes?
There is dysplasia (disordered development of cells) with hypercellular marrow. There is then increased apoptosis of progenitor and mature cells
Myelodysplastic syndromes most commonly occur in who? They have a propensity for evolution into what?
Adults aged > 60 / acute myeloid leukaemia
What happens to the cell number in myelodysplastic syndrome? Explain this?
They stay the same - though the marrow is hypercellular, there is also increased apoptosis
How does acute leukaemia cause pancytopenia?
Proliferation of abnormal ‘blast’ cells prevent normal haemopoiesis from occurring
Which cell count can be variable in acute leukaemia?
WCC
What are some examples of acquired secondary bone marrow failure?
Drugs, B12/folate deficiency, infiltrative disease, viral infections, storage diseases
What are some examples of drugs which can cause pancytopenia?
Chemotherapy, chloramphenicol and alcohol
What is the main cause of pancytopenia due to increased destruction?
Hypersplenism
Why does hypersplenism result in pancytopenia?
Macrophages in the red pulp phagocytose cells, and there is an increased splenic pool
What are some causes of hypersplenism?
Congestion (e.g. portal hypertension), systemic disease (e.g. RA - Felty’s disease) or haematological disease (e.g. splenic lymphoma)
