Other Haem Topics Flashcards
(25 cards)
Hepcidin and feroprotin regulate systemic absorption of iron by inhibition of what?
Enterocyte basolateral iron release
What are the three forms of iron that can be absorbed from the gut?
- Haem iron
- Ferric iron (Fe3+ reduced to Fe2+ iron at the brush boarder)
- Ferretin
Basic pathophysioplogy of anaemia of chronic disease?
Chronic inflammation leads to increased hepcidin production which down regulates iron absorption from the enterocytes leading to anaemia
Where is hepcidin produced?
Hepatocytes
What are blood film findings of thalasaemia?
Aniso-poikilocytosis (different size and shaped red cells)
Target cells
Contracted cells
What is HbH disease?
Alpha thalasaemia in which 3 of the 4 copies of teh alpha globin gene have been lost
What is hydrops faetalis?
It is death of the faetus due to no alpha thalamasia in which all copies of the alpha globin gene have been lost. Not compatible with life
How many alpha globin genes do you have?
4 copies. 2 copies on each chronasome
Features of hyposplenism on blood film?
acanthocytes (spiked cells)
Howel jolly bodies
What test is best for distinguishing non immune intravascular haemolysis from AIHA?
Urinary haemosiderin will be increased in non immune. Not increased in AIAH
What are some differentials for for low platlets in pregnancy?
Gestational thrombocytopenia
ITP
HELLP
TTP
Pre-eclampsia
What platlet level is expected in gestational thrombocytopenia?
almost always >100
- ie someone with a plt of 60 does not have gestational thrombocytopenia
What is the highest risk period of thrombosis in pregnancy?
post partum period
What tests are abnormal for a pt on theraputic dabigatran? What test is used to detect drug precence / action?
Prolongued thrombin time and APTT
Dilute thrombin clotting time (hemeclot assay)
What tests are abnormal for a pt on theraputic rivaroxaban? What test is used to detect drug precence / action?
PT prolonged (varies according to lab)
Modified anti Xa assay specific for rivaroxaban
What tests are abnormal for a pt on theraputic Apixaban? What test is used to detect drug precence / action?
PT prolonged or NORMAL (varies according to lab)
Modified anti Xa assay specific for apixaban
What is the psychophysiology of TTP?
ADAMTS13 deficiency
ADAMTS13 is a protein that cleaves vWF multimers into smaller sections that then form a organised clot. Pts with TTP have an antibody against ADAMTS13 which results in decreased activity (usually <10%). this means that they retain teh very long multimers of vWF wqhich creates a mesh like network of clot that results in microangiopathic haemolysis
This results in consumption of clotting factors and platlets leading to bleeding
Also results in thrombus formaiton and tissue ischemia
What is one of the main side effects of cyclophosphamide?
Bladder irritation and haematuria
What is sytemic mastocytrosis? What organs / tissues are affected?
It is a disease characterized by the infiltration of different tissues by clonaly derived Mast cells
- Typically involves Bone marrow, skin, GI tract, liver and spleen
What is the characteristic mutation in systemic mastocytosis
c-KIT D816V
What specific blood test is typically used to investigate for systemic mastocytosis?
Tryptase level
- will be high in systemic mastocytosis. Normal level does not exclude
Total:beta tryptase ratio > 20:1
What can systemic mastocytosis evolve into?
-> Indolent systemic mastocytosis
-> agresive systemic mastocytosis
-> acute mast cell leukaemia
What is an important sequelae of burkits lymphoma?
spontaneous TLS due to high doubling rate
What is the treatment of TLS?
Monitor urate level and UEC/CMP BD
Treatment:
- Aggressive rehydration
- Allopurinol to control urate level
- Rasburicase if very bad TLS (very expensive alternative to allopurinol)
