Haematology Flashcards
Adverse effects of imatinib?
Weight gain
Oedema
Nausea
Vomiting
Which 1 of the 3 antiphospholipid test confers the most risk of clotting events?
- Lupus anticoagulant
- anti-B2 glycoprotein 1
- IgM anticardiolipin antibody
Which agent reduces mortality in trauma patients at risk of bleeding?
Prothrombinex
What are the indications for Vitamin K warfarin reversal in a patient with an INR:
4.5
>4,5 -10 + high risk of bleeding
>10
4.5:
stop warfarin until INR approaches therapeutic range and then resume dose
Check INR in 24 h
> 4.5 - 10 - high risk of bleeding: Cease warfarin Give 1-2 mg PO or 0.5-1 mg IV Check INR in 24 h
> 10: cease Vit K3-5 mg PO or IV Prothrombinex (FII, IX, X)if bleeding risk high. Check INR after 12-24h.
17p deletion good or poor prognosis?
Always poor.
17 p in CLL
Rivaroxaban is CI in pts with eGFR
False.
Use with caution.
CI if eGFR
Co-administration of posaconazole with Rivaroxaban will increase risk of bleeding. T/F
True, Posa inhibits CYP3A4
MOA Rivaroxaban? How to monitor?
Anti-Xa inhibitor. No reversal agent.
Assay by anti-Xa testing
When do you stop Rivaroxiban/apixiban prior to elective Sx?
Elderly - 2-3 days prior, clearance 44-52 h
Young - 1-2 d prior, clearance 20-36 h
Predictors of recurrence after DVT?
+ve D-dimer 2 weeks after cessation of warfarin
Heritable thrombophilias and low protein C levels are low risk
What are the strong RF for recurrence after DVT?
PE/DVT
> 2 thrombotic events
Male sex
Residual vein thrombus
Vena cava filter
Continued oestrogen use
Cancer
What is the role of hepciden?
Negative regulator of Fe, blocks feroportin and the free movement of Fe across cells
What happens to hepciden in anaemia?
decreases hepciden
What happens to hepciden in inflammation?
Increases transcription of hepciden through IL6 via Stat3, LPS
What are the disease associations for the following haemoglobinopathies?
Thalassemia
B-thalassaemia
a-thal
Haemoglobinopathies
Sickle cell anaemia
Abnormal Hb
High affinity Hb
Thalassemia - micorcytic anamia +normal ferritin
B-thalassaemia - Hb electrophoresis demonstrates increased HbA2
a-thal - molecular test for a-chain deletion
Haemoglobinopathies - abnormal Hb molecules
Sickle cell anaemia - Vascular complications
Abnormal Hb - Anaemia Hb D, O, C, S
High affinity Hb - Polycythemia. Dx ABG paO2
Hydroxyurea has been shown to reduce acute on chronic complication of SCD. T/F
True
CI in pregnancy
What is the commonest inherited bleeding disorder?
vWD, 1 in 100.
Deficient or defective vWF
How does vWF bind to sub endothelium? Role of vWF?
primary binding site on platelets is GP1b-IX-V
required for platelet adhesion, aggregation and stabilises FVIII
What are the types of vW disease?
Type 1-reduced levels, partial reduction in vWF (80% of pts). AD
Type 2- mutations in vWF functional (binding sites) defect, abnormal form of vWF
Type 3 – severe deficiency, total lack of von willebrand factor (AR)
How do you dx Waldenstrom’s macroglobulinaemia?
Presence of any size serum IgM paraprotein
Bone marrow aspirate: inflitration with snake lymphocytes demonstrating plasmacytoid/plasma cell differentiation
Immunophenotype (flow cytometry) - B cell lymphoma, IgM CD19/20+, CD10 and CD5
What feature do you see on film with lead poisoning?
Basophilic stripping
What feature do you see on blood film with Fe def anaemia?
Target cells
Tx for ITP?
Plts 30, no bleeding
Plts 30 and no bleeding
- observation
IVIG can be used instead of steroids when a more rapid increase in plt count is requiored
APTT is a measure of intrinsic pathway (FXI, IX, VIII). T/F
True
APTT does not correct on mixing and no bleeding diathesis. Aetiology?
Lupus anticoagulant most common
FXII and HMWK/Prekalikrein antibody rare
APTT does not correct and bleeding diathesis. Aetiology?
FVIII inhibitor (time dependent)
FIX inhibitor
FXI inhibitor (rare)
Which NOAC can be removed with dialysis?
Haemodiaylsysis works for dabigatran as low protein binding, not for other NOACs as has high protein binding
Does 5q deletion indicate good or poor prognosis in myelodysplastic syndrome?
Good prognosis
Tx for myelodyplastic syndrome?
Supportive care and iron chelating therapy
Azacitadine
Lenolidamide
What are the RF for myelodysplastic syndrome?
DNA damage from previous CTx or radiation, inherited defects in DNA repair
Down syndrome
What drug has been shown to improve survival in Myelodysplasia?
Azacitidine
- a DNA hypomethylating agent
What does the film morphology show in Myelodysplasia?
Anisopoikilocytosis
tear drop cells
oval macrocytes
occasional nucleated red blood cells
What complement change is PNH associated with?
decrease in CD59
What complement change is mesangiocapillary glomerulonephritis associated with?
Production of C3 nephritic factor
How do you diagnose haemochromatosis?
What levels do you aim for phlebotomy?
Risk of progressing to fibrosis?
Tranferrin saturations >60% in M, >50% in F, most sensitive test
Liver Bx provides definitive Dx
- Serum ferritin
- acute phase reactant
- can be elevated by EtOH, steatosis, viral overlaid
- a level of >1000 in absence of above used to indicate the need for biopsy
- the negative predictive value of a normal transferrin saturation and serum ferritin is 97%.NO FURTHER TESTING.
- Liver biopsy
- grade 3 hepatocyte Fe accumulation with an acinar distribution pattern consistent with homozygous genetic haemochromotosis
- stained with Perl’s prussian blue
- grade 3 hepatocyte Fe accumulation with an acinar distribution pattern consistent with homozygous genetic haemochromotosis
Phlebotomy
- Aim serum ferritin maintain levels
What is the mutation in haemochromatosis?
HFE gene located on chromosome 6.
2 missense mutations: C282Y (85%) and H63D (20%)
When if FFP indicated?
To replace coagulation factors
Used when PT/PTT supratherapeutic
When is cryoprecipitate indicated?
Contains fibrinogen, vWF, FVIII, FXIII, Fibronectin (5Fs)
Its a plasma component enriched with fibrinogen.
Used in DIC to replace fibrinogen
What is cerebral venous thrombosis? Presentation? Dx?
Rare, presents in immediate post part period.
Clinical:
Headache
Vomiting
Focal or generalised seizures
Confusion
Blurred vision
Focal neurological deficits
Altered consciousness
Dx:
MRI
What is the hallmark of Factor VII inhibitor?
Bleeding that is first noted after a surgical procedure.
APTT is prolonged
PT is normal
Is there a prolonged APTT in antiphospholipid syndrome?
Yes however thrombosis is the common presentation
What is the most common inherited hypercoagulable state? Which hypercoagulable state is most likely to clot?
Factor V Leiden mutation and prothrombin gene mutation account for 50-60% of cases
patients with defects in Protein C,S and antithrombin are more likely to clot
Mechanism of Factor V mutation leading to thrombosis?
Causes a resistance to the normally inhibitory effects of protein C
Heterozygosity for the factor V Leiden mutation increases the lifetime risk for thrombosis 7-fold
Homozygosity raised the risk 20 fold
Mechanism of Prothrombin gene mutation leading to thrombosis?
A gain of function mutation resulting in elevated levels of prothrombin.
Heterozygous carrier have increased risk of 3-4 fold of venous and possibly arterial thrombosis
Which antiphospholipid abs has the strongest RF for thrombosis? Lupus, anticardiolipin or B2-glycoprotein?
Lupus anticoagulant - highest risk of thrombosis and adverse pregnancy outcomes after 12 weeks gestation
Is Hepcidin increased or decreased in anaemia of chronic disease?
Increased in order to prevent further iron release into the blood
Myelodyplasia: what therapy has prolonged survival compared with supportive care? Therapy fro 5q sydnrome?
Azacitdine
5q syndrome indicates good prognosis. Responds to Lenalidomide, reduces risk of transformation to AML.
GVHD. What is the key cell type involved?
T cell mediated disease. The principle antigenic targets of the T cells of the graft are the host MHC molecules if the patient and donor MHC molecules differ.
What diseases are associated with each of the cryoglobulinaemia?
Type 1 - Waldenstrom’s or MM, produces few complement abnormalities
Type 2 - persistent viral infections, HCV, HIV
Type 3 - systemic rheum conditions
PT high, aPPT normal. Cause?
Problem with FVIII, IX, XI, XII
Heparin the most common
Factor VIII inhibitor if bleeding present
Antiphospholipid syndome in clotting patient
vWD
Haemophilia
PT high, aPPT high. Cause?
Defect in the common pathway e.g. def prothrombin, fibrinogen, factor V or X.
Combined factor deficiencies.
most common cause is RHF with liver congestion, very high PT!
Medications
- abx, not as elevated as RHF
- Warfarin
- Liver disease, Vit K def, excess heaprin, DIC
Which thalassaemia combination gives the highest risk of having a child with a severe form of thalassaemia?
Trait + Trait
What does a normal Hb electrophoresis pattern contain?
HbA 97%
HbA2
Genetic defect in B thal? Types?
defect in B-genes
Normal Hb contains 2 alpha and 2 beta
B-thalassaemia minor (deletion of 1 B-globin gene)
- mild microcytic anaemia or no anaemia.
- Asymptomatic.
- 2-3 fold elevation of HbA2, slight increase in HbF on Hb electrophoresis.
B-thal major (deletion of both B-globin genes):
Resulting severe anaemia -> elevated EPO levels
Hb electrophoresis shows high HbF and HbA2
Fetus and newborn not affected as a2y2 until y switches to beta -> severe anaemia, pallor, growth retardation and heptosplenomegaly due to extramedullary haemopoiesis.
B- thal intermedia (homozygous)
- not all pts with homozygous have full clinical severity
- modulating defects include minor qualitative defects of the B-globin, coinheritance of a-thal trait and increased prod of HbF
What is the best way to prevent post thrombotic syndrome after DVT? What is post thrombotic syndrome?
Exercise training.
Is the development of S&S of chronic venous insufficiency following a DVT
HITS, what are the 4Ts? Score numbers?
Presentation
Ix
Tx
Thrombocytopenia, PLT count fall > 50%
Timing of PLT count fall, 5-10 days (HITs type 2, type 1 is in 1-2 d and recovers spontaneously)
Thrombosis or other sequel
Other cases for thrombocytopenia present
0-3 = low probability
4-5 = intermediate
6-8 = high probability
Presentation:
Fever, chills, dyspnoea, chest pain
THROMBOEMBOLISM (large vessel venous or arterial) is the most common manifestation
Ix:
Immunoassays identify antibodies against heparin/platelet factor 4 (PF4) complexes.
Functional assays measure the platelet-activating capacity of PF4/heparin-antibody complexes.
Functional assays have greater specificity than immunoassays but are time-consuming and not widely available; many institutions offer only immunoassays
Tx:
Heparin cessation
Tx with non heparin anticoagulant:
Danaparoid (LMWH), Fondaparinux (synthetic Factor Xa inhibitor) lepirudin (direct irreversible thrombin inhibitor), argatroban (direct thrombin inhibitor)
Bivalirudin is indicated only in pats with HIT or at risk for HIT undergoing acute cardiac interventions.
Lepirudin is renally cleared.
Argatroban is cleared through liver.
Dx of Pure red cell aplasia?
A very low reticulocyte count,
DDx of microcytic anaemia?
Fe def
Thalassaemia
Less common
- anaemia of chronic disease
- myelodyplasia
- sideroblastic anaemia
- hyperthyroidism
- heavy metal poisoning
What are the 2 major causes of non-restricted Fe def anaemia?
- Absolute Fe def - absent stores
- Functional Fe def - insufficient availability of Fe in the setting of normal to increased Fe stores e.g. anaemia of chronic disease, erythropoietin therapy
What factors are involved in the Fe cycle?
Duodenal enterocytes - absorb
Erythroid precursors - utilise
Reticuloendothelial macrophages - Fe storage and recycling
Hepatocytes - Fe storage and endocrine regulation
What form of Fe do duodenal enterocytes absorb? How does Fe exit enterocyte?
Ferrous Fe2+
Ferroportin exports Fe into the plasma
What is the role of transferrin and transferrin receptor?
Transferrin carries Fe in the plasma
Transferrin receptor mediates uptake into cells
What is the role of Hepcidin in Fe absorption? When does it increase/decrease?
Binds to ferroportin and induces its degradation
Hepcidin increases in Fe overload
Hepcidin decreases in Fe def
What is the major cause of Fe def anaemia in affluent countries?
Blood loss
- GI bleeding e.g. ulcers, malignancy, diverticulitis
- Menstruation
- Diet
- Coeliac disease, partial gastrectomy, PRV etc
What do the Fe studies show in Fe def? Soluble transferrin receptor?
Ferritn reduced
Transferrin increased
TIBC increased
Transferrin saturation reduced
Soluble transferrin receptor increased (derived from bone marrow erythroid precursors and directly proportional to erythropoietic rate
Causes of elevated Ferritin?
Inflammation
Liver disease
Infection
Malignancy
What is the 1st/2nd/3rd line Mx of Fe def? How do you monitor response?
1st Orals
2nd IV
3rd IM
Monitoring Hb and reticulocyte count
What are the causes of anaemia of chronic disease?
Infectious
Neoplastic
Inflammatory
Have an inappropriately low reticulocyte count
What are the mechanisms of anaemia of chronic disease?
- Altered/abnormal Fe homeostasis e.g. reduced absorption, trapping of Fe in macrophages
- Reduced RBC production by the bone marrow e.g. toxicity of erythroid precursors, cytokine mediated effects
- Blunted response to erythropoietin e.g. blunted production, reduced receptors, reduced responsiveness
- Shortened red cell survival e.g. erythrophagocytosis, cytokine and free radical damage
How do you Dx anaemia of chronic disease?
Ferritin normal
Transferrin saturation reduced
Transferrin reduced to normal
Soluble transferrin receptor normal
How can you differentiate between anaemia of chronic disease and Fe def anaemia?
Soluble transferrin receptor is increased in Fe def anaemia, normal in ACD
Cytokine levels increased of ACD
How do you Mx ACD?
Tx underlying cause
If mild, no intervention
Measure erythropoietin level to guide
Fe replacement therapy if Fe def and with erythropoietin therapy
Supportive care - transfusion warranted for severe symptomatic anaemia
What are the strongest RF for VTE?
What is the strongest RF for VTE?
Previous VTE
Fracture of LL
Hip/knee replacement
Hospitilisation for HF or AF/flutter within previous 3 months
Major trauma
MI within 3 months
Spinal cord injury
Which malignancies have the highest risk fro VTE?
Brain
GI
Haem
Lung
Pancreas
Which cytokines are involved in haem disease?
IL -3,7,9,11 - odd number
What is the Tx for ATRA syndrome?
Stop ATRA and give dexamethasone 10 mg IV BD
What is ATRA syndrome due to? S&S?
Cytokine release following differentiation of APL cells.
Causes fluid retention and capillary leak.
Occurs in 1/3 of patients.
Lower rates of ATRA syndrome if chemo is commenced with ATRA.
What are the RF for ALL?
Male- incidence 30% higher in males Children 2-5 y Caucasion Down’s syndrome – 20 x risk for leukemia Radiation exposure
What is the best CTx for Philadelphia +ve ALL?
Imatinib
What is the MOA of Imatinib? What is the main transporter of Imatinib?
Blocks abl function by interfering with ATP binding.
OCT-1 (organic Cation Transporter 1).
Pts with suboptimal response have lower OCT-1 activity.
What is the most effective Tx of MDS with chromosome 5q syndrome (5q31 deletion)?
Lenalidomide.
Can reduce transfusion requirements and reverse cytologic and cytogenic abnormalities.
What is the HASFORD prognostic score?
Measures the response post interferon a Tx in CML. Prognostic score for survivial. APS BEB Age Platelets Slpeen size Basophils Eosinophils Blasts
What is the Tx for chronic phase CML?
Imatinib
Hydroxyurea bulk reduction
IFNa +/- ARA-C
Bone marrow transplant remains the only known curative therapy=sibling allograft (ALLOGENIC)
What are the features of complete haematological response in the Tx of CML?
Complete normalization of peripheral blood
No immature cells in peripheral blood
No S&S of disease including disappearance of splenomegaly
No Philadelphia chromosome
What are the AE of imatinib?
Weight gain Odema Muscle cramps Nausea Deranged LFTs Porphyria-rash
What is the main mechanism of imatinib resistance in CML?
Mutations of BCR-ABL kinase domain.
Outgrowth of leukemic subclones secondary to BCR-ABL mutation.
What is the next line of Tx if a pt with CML is intolerant to Imatinib?
Dasatinib.
Induces cytogenic and haematoligcal response in pts with CML or Philadelphia +ve ALL who cannot tolerate or are resistant to Imatinib.
What is Hodgkin’s lymphoma? Histological classification and prognosis of each?
A malignant proliferation of lymphocytes characterised by the presence of Reed Sternberg cell.
Lymphocyte predominant – best prognosis
Lymphocyte deplete – worst prognosis
Mixed cellular –good prognosis
Nodular sclerosing – most common, good prognosis
What are the poor prognostic factors for Hodgkin’s lymphoma?
Lymphocyte deplete B symptoms Weight loss > 10% in last 6 months Age> 45y Stage IV Hb 15, 000/uL
What is the most common inherited bleeding disorder?
Von Willebrand’s disease
AD
What are the types of VWD?
Type 1-partial reduction in vWF (80% of pts)
Type 2- abnormal form of vWF
Type 3 – total lack of von willebrand factor (AR)
What is the role of vWF?
Large glycoprotein which forms massive multimers up to 1, 000, 000 Da in size and promotes platelet adhesion to damaged endothelium.
Carrier molecule for factor VIII.
What is the treatment for vWD?
Tranexamic acid for mild bleeding
Desmopressin (DDAVP) to raise levels of vWF by inducing release of vWF from Weibel-Palade bodies in endothelial cells
Factor VIII concentrate
What is the main AE of DDVAP (vasopressin)?
Hyponatraemia
What is a leukamoid reaction?
Describes the presence of immature cells such as myeloblasts, promyelocytes and nucleated red cells in the peripheral blood. May be due to infiltration of the bone marrow causing the immature cells to be pushed out or sudden demand for new cells.
Causes are severe infection, severe haemolysis, massive haemmorhage, metsatic can with bone marrow infiltration.
How can you differentiate leukamoid reaction from CML?
Leukamoid reaction
-high leucocyte alkaline phosphatase score
toxic granulation (Dohle bodies) in the white cells
Left shift of neutrophils i.e. three or less segments of the nucleus.
CML
-low leucocyte alkaline phosphatase score.
What are the features of amyloid light chain amyloidosis?
Nephrotic range proteinuria Acquired factor X def leading to high INR Postural hypotension Macroglossia Low grade plasma dyscrasia
What is the purpose of a mixing study?
To asses if the pt has a factor def or an clotting factor inhibitor present.
If the mixing study corrects, pt has factor def.
If it does not correct, pt has a clotting factor inhibitor present.
What factors are involved in the extrinsic pathway?
Tissue factor III
VII
PT checks extrinsic pathway.
What factors are involved in the intrinsic pathway?
XII (Prekallikrein) HMWK VIII IX XI XII APTT checks intrinsic pathway
Which pathway does the thrombin clotting time check?
The common pathway (Factor X)
What is romiplostim?
A fusion protein analogue of thrombopoietin, a hormone that regulates platelet production.
Romiplostim stimulates the patient’s megakaryocytes to produce platelets at a more rapid than normal rate thus overwhelming the immune system’s ability to destroy them.
what are the AE of romiplostim?
Myalgia
Joint and extremity discomfort
Insomnia
Thrombocytosis ->clots and bone marrow fibrosis