Haem Flashcards
What’s the pattern of inherited of haemophilia?
X Linked recessive
What are the 4T s in HIT pretest probability?
Thrombocytopenia (>50% decrease or platelet ~20)
Timing of thrombocytopenia (5-14 days)
Thrombosis (or skin necrosis)
OTher causes excluded
What test for the extrinsic pathway?
PT
What factors are in the intrinsic pathway?
TENET
(twelve-eleven-nine-eight-ten)
What is bound in HIT?
Platelet Factor 4
(Autoantibodies)
What receptor on platelets binds to vwf?
GP1B-V-IX (reversible adhesion to exposed extracellular matrix)
What does platelet adhesion to ECM trigger?
GPIIb-IIIa activation (irreversybinding to matrix ligand and platelet activation)
What does GPIIb-IIIa do?
Mediates platelet aggregation + binds fibrin to form fibrin clot
What does clopidogrel and ticagrelor work on?
P2Y receptor antagonists
PT-N, APTT-long, TT-N Fibr-N, Plt- N, diagnosis?
Factor VIII, IX XI, XII deficiency, vwf def
What is dilute Russel venom viper test used for?
Detecting presence of antiphospholipids, (prolonged test), esp b2gp.
Is also prolonged if DOAC present.
What hormonal state is the most risky for clots?
Post-partum
How does VITT doffer from HIT?
No heparin exposure
What is the bleeding pattern with platelet type bleeding disorders
Skin, mucosal membranes, vaginal, petichiae common, prolonged bleeding from skin cutes, bleeding immediately
What is the bleeding pattern with clotting factor disorders?
Deep soft tissue bleeds, muscles, joints, minimal bleeding from skin cuts as primary haemostasis intact, bleeding delayed 1-2 days and often severe (e.g post op day2)
What clotting factor deficiency has no clinical significance?
XII
What is inheritance of haemophilia?
X-Linked recessive, 1/3 if cases have no apparent family history
What is emicizumab?
MAB used in Haemophilia A to act as factor 8 and bond X to IX
What is type 1 VWF disease?
Partial quantitative deficiency. most common , 70-80%
What is VWD 2B?
Increased affinity of VWF for GP1B, selective deficiency of high molecular weight multimeters
What is VWD type 3?
Complete deficiency VWF
How to treat VWD?
Replace VWF, dvavp in acute bleeding if required (releases stores from wible plaby bodies)
What is the reversal agent for heparin?
Protamine
What does PFA100 test?
Primary haemostasis - used in assessment of VWD
How is iron absorbed?
In the gut through DMT1 receptors on enterocytes
What is the action of feroportin?
Allows iron to exit the cell into the circulation and become bound to transferrin in the blood
What is the role of hepcidin?
Inactivates feroportin receptors on macropophages and enterocytes - traps iron in the cell.
What are the iron studies in iron deficiency anaemia?
Transferrin - High
Trabsferrin saturation - low
Ferritin - low
What is the pathogenesis/ autoimmune target in ITP?
Autoantibodies towards Glycoprotein IIb/IIa complex
What is the outcome of reduced G6PD?
Reduced NADPH - making red cells more susceptible to damage by oxidative stress
BCR-ABL mutation
t(9;22)
What are the driver mutations in ET/PMF?
JAK2V617F
CALR (CALR 1 deletion mutation ass with mylofribrosis transformation)
MPL (test these two if JAK2 negative)
What is the treatment criteria fo ET?
CVD risk factors present
JA2 mutation
Age >60
History of thrommbosis
What is treatment for intermediate and high risk ET?
Hydroxyurea + aspirin
Add warfarin if VENOUS thrombosis
What is the treatment target for HCT in PV?
<45% Hct
What is the hb level required for dx of PV
160 women, 165 men
What are risk indicators for cytoreductive therapy in PV?
High risk ( Age >60, previous thrombotic event)
Poor tolerance of phlebotomy
WCC >15
Uncontrolled myeloproliferation
- Increasing splenomegaly
Uncontrolled symptoms ( HTN, blurred vision sx of hyperviscosity)
What is ruxolitinib?
JAK inhibitor - used to treat PV, superior at HCT control than hydrocycarbamide (hydroxyurea)
What are the bone marrow findings in PV?
Hypercellular, panmyelosis, pleomorphic megalokaryocytes
What are contraindications for aspirin therapy in ET?
Extreme thromocytosis, aquired VFD, low risk CALR positive
What are toxicities associated with CAR-T cells?
Cytokine storm - fro mCARTcell expansion
ICANS: immune effector cell associated neurotoxicity syndrome
How do you manage cytokine release storm after CART cells?
Anti IL-6 - tocilizumab and corticosteroids.
Supportive care
What is ICANS?
Immune effector cell associated neurotoxicity syndrome
- Disturbed blood brain barrier in the setting of severe systemic inflammation.
Confusion, headache, attention deficits, word finding difficulties, focal neurological deficits, or encephalopathy to life threatening cerebral oedema, transient coma, or seizures
Pathogenesis not well understood.
How to treat ICANS?
Corticosteroids, neurology review, seizure prophylaxis, supportive care
Presence of basophils on blood film is indicative of what?
CML
How do you treat CML?
Imatinib
Nilotinib - quicker and deeper responses
Dasatinib
What are side effects of imatinib?
Fluid retention, muscle pain, GI issues, fatigue
What mutation causes resistance to usual treatment for CML?
T315l - use ponatinib instead
Can TKIs be used in pregnancy?
No they are teratogenic
Can you get GVHD in BMT in the aplastic phase?
No- the graft hasnt started to function - pre-engraftment
What is sinusoidal obstructive syndrome?
Microthrombi in the hepatic venles causing occlusion of liver flow - cholestatic liver pattern.
Enlarged, tender liver, ascites, pulomonary infiltrates, oedema. This is an early complication of BMT
How do you treat Hepatic veno-occlusive disease?
Defibrotide - antithrombotic/anti inflammatory effect to dissolve microthrombi.
Ursodeoxycolic acid - billiary acid suppression
What cell has CD34?
Stem cell
What cell has CD3?
T lymphocytes
What are haematological indications for BMT?
AML, ALL, myelodysplasia, severe aplatic anaemia , NHL, myeloma, CML
Thallasaemia, sickle cell
Whn does engraftment happen after BMT?
12-21 days
How long does it take for immune reconstitution?
Up to 2 years
What is the most important mismatch in BMT?
HLA (A B OR C)