Pancytopenia Flashcards
what is pancytopenia
a defic of blood cells of all lineages (but generally exclude lymphocytes)
anaemia, thrombocytopenia, neutropenia
does pancytopenia mean bone marrow failure
not always
lifespan of red cells
neutrophils
platelets
120 days
7-8 hours
7-10 days
turnover for red cells
neutrophils
platelets
2.5 mill per second are lost and produced
1-2 million
1 million
causes of pan
reduced production or increased destruction
reduced production causes
inherited
primary acquired - stem cell defect
secondary acquired - absence of b12 and folate
why do inherited marrow failure syndromes arise
what do they lead to
due to defects in DNA repair/ribosomes
cancer pre dispostion
congenital anomalies
impaired haemopoiesis
fanconi’s anaemia is what
signs /symo
inherited marrow failure synd
short, skin pigment abnormalities, radial ray abnormalities, hypogenitilia, endocrinopathies, GI defects, CDV, renal, haem
median age onset for fanconis what happens progress prognosis risk
7 years
unable to correct inter strand cross links (DNA damage)
macrocytosis followed by thrombocytopenia then neutropenia
bone marrow failure (aphasia) risk is 84% by 20 years
leuk risk 52% by 40 years
primary acquired bone marrow failure
plastic anaemia
myelodysplastic syndromes
acute leuk
aplastic anaemia
autoimmune attack against haemopoietic stem cells
autoreactice T cells (esp CD* and sometimes CD4) produce IFN-gamma and TNF-alpha
this leads to lack of production of cells
myelodysplastic syndromes
dysplasia
hypercellular marrow
increased apoptosis of progenitor and mature cells (ineffective haemopoiesis)
propensity for evolution into AML 20-30% px
why can acute leuk cause pan
prolif of abnormal cells (blasts ) from leukaemia stem cells
fail to differentiate or mature into normal cells
prevents normal haemopoietic sten/proginator development by hijacking/altering haemopietic niche and marrow microenviroment
causes of secondary bone marrow failure
drug induced -> aplasia
B12 and folate defic - affects all lineages (hypercellular)
infiltrative - non haemopoietic malig infiltration, lymphoma
viral (e.g. HIV)/storage diseases
causes of increased destruction of cells
hypersplenism
hypersplenism
increased splenic pool
-increased destruction that exceeds bone marrow production - assoc w enlarged spleen
splenic red cell mass
normal spleen 5%
hypersplenism 40%
red cell transit
normal spleen fast
hypersplenism slow
splenic platelet pool
normal 20-40% in the spleen
hypersplenism 90% can sit in the spleen
is the splenic size linked to the hypersplenism
no
causes of hyperpslenism
splenic congestion - portal htn, congestive HD
systemis dx - rheumatoid (felty’s)
haem dx - splenic lymphoma
what are the clinical features of pan divided into
lack of circulating blood cells
the cause of the pancytopaenia
symptoms- for lack of cells
anaemia - fatigue, SOB, cardiovascular compromise
neutropenia - infections
thrombocytopenia - bleeding in purport, petechiae
clinical features depending on cause
Fanconi – skeleteal, genital, renal
Acquired – aplastic – history of other AI conditions, B12 and folate may have neuro problems, Infections
