Haematology Flashcards
fully saturated Hb group will bind how much O2?
1.34ml
Tx of CML?
Imatinib
what is immunophenotyping?
ABs used to detect specific antigens on cells to determine type and numbers
what is plasma and how is it obtained?
liquid that blood cells are suspended in
obtained by anticoagulation
What is serum and how is it obtained?
liquid without cells or clotting factors (plasma- fibrinogen)
obtained by clotting blood
how much O2 will bind in a fully saturated Hb
1.34ml
What enzyme facilitates formation of HCO3?
carbonic anhydrase
where are alpha genes?
chromo 16
where are beta genes?
chromo 11
target cells?
seen in thalassemias
HBh disease characteristics and cause?
one alpha globin gene left
severe anemia
HbH on elctrophoresis
beta tetromers
HBBarts features?
gamma tetramer
death in utero
Where are alpha tetrameres seen?
b thalassemia major
what is raised HbA2 diagnostic of?
B thalassemia trait
HIV infects what cells and what happens?
Cd4 Th cells
Th cell numbers decrease
Viral load increase as virus replicates
What do Tc cells bind to?
MHC1
so have CD4
What causes the acute HIV syndrome?
immune cell activation and death
body is trying to fight off the virus
symptoms after 2-3 weeks of infection
very high risk of transmission
What is phase 2 of HIV?
chronic HIV/latency phase/assymptomatic
body is managing to control viral load however over time the viral load slowly increases and Th lymphocyte count decreases.
usually asymptomatic then start getting symptoms as viral load over takes lymphocyte count
lasts about 10 years
What is aids?
state of depleted immune system
Th lymphocyte count is so low that the body cant fight the of simplest of virused
What are aids defining illnesses?
illnesses that wouldnt cause symptoms in anyone else
fungal pneumonias: pneumocytis pneumonia, crytococcus pneumonia
What are some main characteristics of AIDS?
low CD4 cells in blood
any aid defining illnesses
how is HIV spread?
breast milk
blood
sexual fluids
What is leukopenia?
low wbc count in the blood
What is leukocytosis?
high white cell count in the blood
what is neutropenia and when is it classically seen?
low neutrophils
drug toxicity eg chemo
very severe infection (increased production of neutrophils but the majority pass into the tissues to fight the infection)
How would you treat neutropenia?
gmcsf- granulocyte monocyte colony stimulating factor
gscf- granulocyte colony stimulating factor
both used to boost granulocyte thus neutrophil production
What is lymphopenia and some common causes?
low number of circulating lymphocytes
immunodeficiency
autoimmune destruction (antibodies against WBC)
whole body radiation- lymphocytes are very sensitive to radiation
high cortisol state- induce apoptosis of lymphocytes
What happens in Di george syndrome?
failure to develop third and fourth pharengeal pouch thus thymus so t cells cant mature properly
What is neutrophilic leukocytosis and when does it occur?
increased neutrophils in the blood
bacterial infection
tissue necrosis
high cortisol state
How do you recognise the presence of immature neutrophils in the blood and when does this occur?
decreased fc receptors on the surface- decreased CD16- so they dont function quite as well
in situations when the bone marrow increases production and releases immature cells
why does high cortisol state increase neutrophils?
cortisol causes release of the storage pool of neutrophils by disrupting the adhesion of the pool causing them to fall into the blood
When does monocytosis occur?
chronic inflammatory states
malignancy
When does oesinophillia occur?
allergies
parasites
hodgkin lymphome (increased IL 5 production)
When do you see basophilia?
CML
when do you see lymphocytic leukocytosis?
viral infections with the exception of bacteria bordetella pertusis (blocks the lymphocytes from entering tissues so increased numbers in the blood)
What causes infectious mononucleosis/glandular fever?
EBV infection
results in lymphocytic leukocytosis of reactive CD8 Tc cells
How do you screen for glandular fever?
monospot test identifies IgM antibodies
How do you definately diagnose glandular fever?
Ebv viral capsidantigen
What is thrombophilia?
hypercoagulability state
inherited or acquired abnormality/ deficiency of naturally occuring anticoagulants that increases risk of thrombosis
When do you suspect thrombophilia?
Individuals with recurrent DVTs or PEs and not other risk factors
any individual with a DVT <45 years
What are the four main inherited thrombophilias?
Activated protein C resistence/Factor V leiden
Prothrombin gene mutation
Protein C and S deficiency
Antithrombin deficiency
What is APC resistance/factor V leiden?
factor V leiden is an abnormal/mutated factor V which activated protein C cant break down/anticoagulate
What happens in prothrombin gene mutation?
results in high prothrombin levels and increased thrombosis
What happens in protein C and S deficiency?
reduced anticoagulant effect on VIII/IXa and V/Xa
What activates protein C and S?
thrombin bound to thrombomodulin on surface of endothelial cells
What are the Vit K dependent clotting factors/proteins?
prothrombin VII XI X PC&S
how does warfarin work?
blocks vit k oxide reductsae reducing the activation of vit k which decreases vit k dependant clotting factors
How does heparin work?
works as a co factor binding to and potentiating/ increasing the effects of antithrombin by enhancing the binding of antithrombin to factor Xa and II/prothrombin for inactivation
What does antithrombin do?
inactivates thrombin and enzymes involved in the coagulation cascade
What is the main acquired thrombophilia?
antiphospholipid syndrome
What is antiphospholipid syndrome?
autoimmune hypercoaguable state caused by antiphospholipid antibodies
commonly in SLE or preganancy
Prophylactic treatment of antiphospholipid syndrome in pregnancy?
heparin and aspirin (this is a disease that increases thrombosis risk in venous and arterial system so anticoagulants and antiplatlets needed)
What is management of DVT?
acutely- LMWH long term anticoagulation: 3 months if precipitating factor 6 months is no precipitating factor warfarin
What is warfarin INR target?
2-3 if no events
3-4 if events
What is the treatment of thrombopillia?
life long anticoagulation- warfarin
DVT/ PE in pregnancy management?
LMWheparin
First line investigationin PE?
CT pulmonary angiogram- high risk
low risk- D dimer if positive CT
What is haemophillia?
impaired ability to make blood clots causing prolonged bleeding and easy bruising
What are the main types of haemophilias?
Haemophillia A
Haemophillia B
acquired haemophilia
What is haemophilia A?
X linked recessive
factor VIII deficiency
What is haemophillia B?
X linked recessive factor IX deficiency
What are the typical clinical presentations of haemophilias and why?
bleeding into joints/haemarthrosis
soft tissue bleeds
bruising in toddlers
prolonged bleeds after surgery or dental extraction
When can desmopressin be useful and why?
VWF diesease
haemophillia A
desmopressin can increase the secretion of VWF resultingi n a subsequent increase in VIII
Management of haemophillia A?
avoid NSAIDs and IM injections
pressure and elevation
desmopressin
What are some examples of acquired multiple clotting factor deficiencies?
liver failure- main site of production for clotting factors
Vit K deficiency/warfarin use- factors II, VII, IX, X need vit K for production
What is acquired haemophilia?
rare
autoimmune ABs to factor VIII