Pancytopenia Flashcards
What is pancytopenia?
a deficiency of blood cells of all lineages (generally excludes lymphocytes)
anaemia + neutropenia + thrombocytopenia
What are the causes of reduced production resulting in pancytopenia?
bone marrow failure
What are the characteristics of inherited marrow failure syndromes?
cancer predisposition; imapired haemopoiesis; congenital anomalies
Why do inherited marrow failure syndromes arise?
defects in DNA repair/ribosomes
give an example of an inherited marrow failure syndrome?
Fanconi’s anaemia
What are the features of fanconi’s anaemia?
short stature; skin pigment abnormalies; hypogenitalia; GI defects; CVS; renal; radial ray abnormalities
What is the dermatomogical feature of fanconi’s anaemia?
cafe au lait spots
What is the average age of onset of fanconis anaemia?
7 years
What is the underlying defect in Fanconi’s anaemia?
unable to correct inter-strand cross-links (DNA damage)
What are the blood changes seen in fanconi’s anaemia?
macrocytosis–thrombocyopenia–neutropenia
Waht are the causes of acquired primary bone marrow failure?
idiopathic aplastic anaemia; myelodysplastic syndromes; acute leukaemia
What is the pathogenesis of aplastic anaemia?
auto-reactive T cells which produce IFN-gamma and TNF-alpha which prevents development of stem cells and precursors
What are hte features of myelodysplastic syndrome?
dysplasia; hypercellular marrow; increased apoptosis of progenitor and mature cells
What cancer does myelodysplastic syndrome evolve into?
AML
Why can acute leukaemia cause pancytopenia?
proliferation of abnormal cells (blasts) from leukaemic stem cells, failure to differentiate or mature into normal cells; prevention of normal haemopoeitic stem development by hijacking the niche and marrow microenviornment
What are the causes of secondary bone marrow failure?
drugs; B12/folate deficinecy; infilitrative; infections; storage disease
What drugs can cause marrow aplasia?
chemotherapy; chloramphenicol; alcohol
What is the cellularity of the marrow with B12/folate deficinecy?
hypercellular
What happens in hypersplenism?
increased splenic pool of RBCs and platelets; increased destruction; slower RBC transit
What are the causes of hypersplenism?
portal hypertension; CCF; RA (Felty’s); splenic lymphoma
What is Felty’s syndrome?
RA; splenomegaly; pancytopenia
What infections are implicated in pancytopenia?
HIV; mycobacetria
What are the signs of anaemia?
fatigue; SOB; CVS compromise
What are the signs of thrombocytopenia?
purpura; petechiae; wet bleeds
