Haematology Flashcards
What effect does DIC have on D-Dimer?
Why?
D-Dimer is elevated, as it reflects an increase in fibrin degradation products with the pathological and extensive fibrinolysis that occurs
What is the hallmark of DIC on coagulation profile?
Decreased fibrinogen
What will the blood film show in DIC?
Schistocytes / helmet cells due to microangiopathic haemolysis
Thrombocytopaenia
What do smudge cells on blood film indicate?
Chronic Lymphocytic Leukaemia
What is the difference between SLL and CLL?
SLL - primarily nodal, <5 lymphocytes in blood
CLL - primarily blood, >5 lymphocytes in blood
What haematological condition is venetoclax used for?
Refractory CLL
Which agent is used for MDS with del5q?
Lenalidomide
What are some side effects of imatinib?
Weight gain, nausea, diarrhoea, oedema, muscle cramps
What is the role of OCT-1?
It is the main transporter for imatinib.
High OCT-1 activity is associated with better response to imatinib
What is the most common finding on presentation of multiple myeloma?
Anaemia
What is daratumumab? What is its role in multiple myeloma?
Anti-38 monoclonal ab
Approved for use in relapsed MM
What is the main cause of hypercalcaemia in multiple myeloma?
Primarily due to increased osteoclastic bone resorption
What are the two main prognostic markers in multiple myeloma?
Beta 2 microglobulin + albumin
What do Dohle bodies in white cells indicate?
Toxic granulation
Seen in leukamoid reaction = immature cells in the blood due to
- severe infection
- severe sepsis
- massive haemorrhage
- bone marrow infiltration
What condition predisposes to warfarin-induced skin necrosis?
Protein C deficiency
Blood film = target cells + teardrop cells
Thalassaemia
Blood film = pencil cells
iron deficiency
Blood film = Bite cells
Caused by Heinz bodies, seen in oxidative haemolysis e.g. G6PD deficiency
Blood film = Spur cells (irregular projections)
Liver disease
Blood film = burr cells / echinocytes (regular projections_
Uraemia
Blood film = tear drop cells
Extramedullary haematopoiesis or thalassaemia
Blood film = nucleated RBCs
Severe haemolysis, hypoxia, stress or PMF
Blood film = Howell-Jolly bodies
Hyposplenism
They are nuclear remnants of RBCs usually removed by spleen
Blood film = any blasts
NEVER NORMAL on peripheral smear
Suggests haematological malignancy
Blood film = Auer rods
Acute myeloid leukaemia
Blood film = schistocytes
Microangiopathic haemolysis
What haem malignancy is HTLV-1 associated with?
Acute T-lymphoblastic Leukaemia / Lymphoma
What haem malignancy is EBV associated with?
Burkitt lymphoma
PTLD
Hodgkin lymphoma
What haem malignancy is HIV associated with?
DLBCL
Burkitt lymphoma
Hodgkin lymphoma
Primary CNS lymphoma
What haem malignancy is HHV-6 associated with?
Primary effusion lymphoma
What haem malignancy is benzene associated with?
Multiple myeloma
What haem malignancy is hair dye associated with?
Follicular lymphoma
What cytogenetic marker is associated with APML?
t(15,17)
What is the strongest adverse prognostic factor in AML?
Age >60
What is the biggest risk factor for recurrent DVT/PE?
Unprovoked VTE
What are the high risk inherited thrombophilias?
- AT deficiency
- Protein C / S deficiency
- Factor V Leiden homozygote
- Prothrombin gene mutation homozygote
- Double heterozygotes for FVL and PGM
What kind of thrombosis are APLS at risk of?
Arterial AND venous
What are the APLS ab to test for?
Anti-Beta 2 glycoprotein 1
Anti-cardiolipin
Lupus anticoagulant
Must be repeated after 12 weeks to make diagnosis
What are the initial laboratory findings in lupus anticoagulant?
Prolonged APTT that does not correct with mixing.
Prolonged reptilase time, normal TCT
What are the 3 causes of prolonged APTT?
Factor deficiency
Inhibitor
Drugs
What are the 2 possible inhibitors that would prolong APTT?
Lupus anticoagulant
Specific factor inhibitor
Which of the APLS ab have the weakest correlation with thrombosis?
Anti-cardiolipin ab
What is the greatest risk factor for VTE in pregnancy?
Prior VTE
What are the direct thrombin inhibitors used in HITS?
Danaparoid
Argatroban
Bivalirudin
What is the main use of fondaparinux?
In patients with HITS + normal renal fx
Which DOAC is most reliant on renal function for excretion?
Dabigatran
What is the anticoagulant of choice in prosthetic heart valves?
Warfarin
What are 2 GpIIb/IIIa inhibitors?
What is their use?
Abciximab
Tirofiban
Coronary angiography
What type of bleeding is more characteristic of factor deficiencies?
Haemarthroses, deep muscle bleeds
What type of bleeding is more characteristic of platelet / vWF disorders?
Epistaxis + GI bleeding, skin, genito-urinary
Umbilical stump bleeding -> classic deficiency?
Factor 13
What are the factors involved in the common coagulation pathway?
Factor X, factor V, factor II (prothrombin), and factor I (fibrinogen)
**think of our currency, $1, $2, $5, $10
Which pathway does the APTT measure?
Which factors are involved?
Intrinsic pathway + common
Factor XII, XI, IX, VIII
Factor 1, 2, 5, 10
Which pathway does the PT measure?
Which factors are involved?
Extrinsic + common
Factor 7, TF
Factor 1, 2, 5, 10
Which factor drops first in warfarin administration?
Factor 7
Why is there a theoretical risk of pro-thrombotic state with warfarin initiation?
___
What level of Factor is present in ‘severe’ haemophilia?
<1%
Which type of haemophilia more commonly develop inhibitors?
Haemophilia A
What is the mechanism of tranexamic acid?
Forms a reversible complex that displaces plasminogen from fibrin -> inhibition of fibrinolysis
Also inhibits the proteolytic activity of plasmin
What is vWF’s role related to Factor VIII?
Acts as “chaperone” which binds Factor VIII to prevent its premature degradation
Which blood group has lower levels of vWF?
Group O blood group has lower vWF
What is the 1st line therapy for mild vWD?
DDAVP - releases vWF and FActor 8 from storage sites
What is the defect in Bernard-Soulier Disease?
What is it phenotypically similar to?
Glycoprotein 1b-IX-V
vWD
What is the defect in Glanzmann thrombasthenia?
What is the phenotype?
Glycoprotein 2b/3a complex
Severe bleeding diathesis
Which therapy raises platelets fastest (other than platelets) in ITP?
IVIG (faster than steroids)
What is the indication (in Australia) for TPO-mimetics in ITP?
For failed splenectomy or splenectomy contraindicated
What is the main treatment for TTP?
Plasma exchange
What is the main treatment for atypical HUS?
Eculizumab - C5 inhibitor
What is the pathogenesis of HITS?
Results from an auto-antibody against Platelet Factor 4 (PF4) in complex with heparin
What are the 4 Ts in the score for HITS?
Thrombocytopaenia severity
Thrombosis
Timing of onset after exposure
Other cause for thrombocytopaenia
Alternatives to heparin in HITS?
Direct thrombin inhibitors - bivalirudin, argatroban
Danaparoid
Fondaparinux
Which blood groups can AB people receive PRBC from?
ALL
Which ABO antibodies are in serum of O group?
Anti-A and Anti-B
Which ABO antibodies are in serum of AB group?
None
What are the VTE-prevention recommendations for a pregnant woman with no personal history of VTE, but a FHx and a Factor V Leiden mutation?
Observation antepartum
Only consider postpartum prophylaxis if other risk factors
What are the VTE-prevention recommendations for a pregnant woman with no personal Hx VTE who has antithrombin deficiency?
Therapeutic LMWH antepartum + 6/52 postpartum
What are the VTE-prevention recommendations for a pregnant woman with no personal Hx VTE who has a Protein C or S deficiency?
Prophylactic LMWH antepartum + 6/52 postpartum
What are the VTE-prevention recommendations for a pregnant woman with single prior provoked VTE (not during pregnancy)?
Observation antepartum, and prophylactic LMWH 6/52 postpartum
What are the VTE-prevention recommendations for a pregnant woman with single prior pregnancy-provoked VTE?
Prophylactic LMWH antepartum + 6/52 postpartum
What are the VTE-prevention recommendations for a pregnant woman with recurrent unprovoked VTE?
Therapeutic anticoagulation throughout
What is Andaxenet Alfa?
Recombinant FXa molecule
Works as FXa antidote by being a decoy for the drug to bind to
Where does Factor VII work in the coagulation cascade?
Initiation of clotting
Binds to Tissue Factor, which activates Factor X
What is the role of platelets in coagulation?
Platelets provide binding sites for coagulation factors and a phospholipid surface that promotes assembly of multicomponent complexes (i.e. X-ase, Prothrombinase)
What is contained in the prothrombinase complex?
Factor Xa + Factor Va
What is contained in the Extrinsic X-ase complex?
Factor VIIa + TF
What is contained in the Intrinsic X-ase complex?
Factor VIIIa + Factor IXa