Haematology/ Oncology Flashcards
what is the most common thrombophilia?
Activated protein C resistance aka Factor V Leiden
- heterozygotes - 5 x risk thrombosis
- homozygotes - 50 x risk
MOA of docetaxel?
Acts on microtubules:
prevents microtubule depolymerisation & disassembly -> decreasing free tubulin
SE of docetaxel?
Neutropenia
What are the different types of cryoglobulinaemia?
3 Types: Type I (25%): monoclonal Type II (25%): mixed monoclonal and polyclonal, usually with rheumatoid factor. Type III (50%): polyclonal: usually with rheumatoid factor
What is cryoglobulinaemia?
immunoglobulins which undergo reversible precipitation at 4 deg, dissolve when warmed to 37 deg.
Type 1 Cryoglobulinaemia assoc?
- monoclonal
- > Waldenstrom macroglobulinaemia, Multiple myeloma
Type II Cryoglobulinaemia assoc w?
mixed monoclonal/ polyclonal (usually with RF)
-> Hep C, Rheumatoid arthritis, Sjogren’s, lymphoma
Type III Cryoglobulinaemia assoc with?
- polyclonal: usually with RF.
- > Rheumatoid arthritis, Sjogrens
Symptoms/ signs of Cryoglobulinaemia?
- Raynauds (type I)
- Cutaneous: purpura, distal ulceration
- arthralgia
- Renal - diffuse glomerulonephritis
Ix of Cryoglobulinaemia?
- Low complement (esp C4)
- High ESR
Mx of cryoglobulinaemia?
Immunosuppression, plasmapheresis
Management of SVCO?
- endovascular stenting usually to provide symptom relief
- often given steroids e.g. dexamethasone
most reliable lab test to screen for hereditary angioedema inbetween attacks?
C4 levels
- characteristically low
*C2 also low but serum C4 most reliable and widely used screening tool
best diagnostic test to send during acute attack of hereditary angioedema?
C1 inhibitor levels- low
Management of acute attack of hereditary angioedema?
IV C1-inhibitor concentrate,
2nd line: FFP
- HAE does not respond to adrenaline, antihistamines or steroids.
Prophylaxis of attacks in hereditary angioedema?
anabolic steroid - Danazol
Or tranexamic acid
Diagnosis of hereditary spherocytosis?
- typical clinical features (FHx) + lab Ix (spherocytes)
- if equivocal: EMA binding test and Cryohaemolysis test
Diagnosis of atypical presentations of hereditary spherocytosis?
electrophoresis analysis of erythrocyte membranes
Management of acute haemolytic crisis in hereditary spherocytosis?
- supportive
- transfusion if necessary
Long term management of hereditary spherocytosis?
folate replacement, splenectomy
t(9;22) - Philadelphia chromosome
- CML (present in >95%)
- poor prognostic indicator in ALL
t(15;17) - fusion of PML and RAR-alpha genes
Acute promyelocytic leukaemia
t(8;14) - MYC oncogene
Burkitt’s lymphoma
t(11;14) - deregulation of the cyclin D1 (BCL-1) gene
Mantle cell lymphoma
t(14;18) - increased BCL-2 transcription
follicular lymphoma
causes of warm AIHA?
- autoimmune disease: e.g. systemic lupus erythematosus*
- neoplasia: e.g. lymphoma, CLL
- drugs: e.g. methyldopa
Features of warm AIHA?
- usually IgG antibody
- haemolysis at extravascular sites e.g. spleen
Management of warm AIHA?
steroids, immunosuppression, splenectomy
causes of cold AIHA?
- neoplasia: e.g. lymphoma
- infections: e.g. mycoplasma, EBV
features of cold AIHA?
- usually igM antibody
- commonly intravascular haemolysis
- Raynauds/ acrocynanosis
- responds less well to steroids
clinical features of myelofibrosis?
- symptoms of anaemia
- massive splenomegaly
- hyper metabolic symptoms: weight loss, night sweats
lab findings of myelofibrosis?
- anaemia
- high WBC, Pl count
- blood film: tear drop poikilocytes
- dry tap on BM biopsy-> trephine biopsy needed
- high LDH and urate (increased cell turnover)
What chemical mediator is mainly responsible for the tissue oedema seen in patients in hereditary angioedema?
bradykinin
- uncontrolled release of bradykinin-> oedema of tissues
features of thrombotic thrombocytopenic purpura?
- fever
- fluctuating neuro signs (microemboli)
- microangiopathic haemolytic anaemia
- thrombocytopenia
- renal failure
pathogenesis of Thrombotic thrombocytopenic purpura?
- deficiency of ADAMTS13 (a metalloprotease enzyme) that breaks down large multimers of vWF
- abnormally large and sticky multimers of vWF cause platelets to clump within vessels
Causes of thrombotic thrombocytopenic purpura?
post-infection e.g. urinary, gastrointestinal
pregnancy
drugs: ciclosporin, oral contraceptive pill, penicillin, clopidogrel, aciclovir
tumours
SLE
HIV
features of Waldenstrom’s macroglobulinaemia?
- monoclonal IgM paraproteinaemia
- systemic upset: weight loss, lethargy
- hyperviscosity syndrome e.g. visual disturbance
- hepatosplenomegaly
- lymphadenopathy
- cryoglobulinaemia e.g. Raynaud’s
features of lead poisoning?
- abdo pain
- peripheral neuropathy (mainly motor)
- fatigue
- constipation
- blue lines on gum margin (only 20% of adult patients, very rare in children)
Ix of lead poisoning?
- Blood lead level
- FBC: microcytic anaemia
- blood film: basophilic stippling, clover leaf morphology
- raised serum/ urine lvls of delta aminolaevulinic acid (similar to acute intermittent porphyria)
- urinary coproporphyrin raised
management of lead poisoning?
various chelating agents are currently used: dimercaptosuccinic acid (DMSA) D-penicillamine EDTA dimercaprol
Sickle cell: what medication is taken long term to reduce incidence of complications and acute crises?
Hydroxycarbamide
- increases HbF
- makes cells less likely to sickle
- advised to not be taken in pregnancy
features of essential thrombocytosis?
- Pl count >600
- thrombosis and haemorrhage
- characteristic symptom is burning sensation in the hands
- JAK2 mutation in 50%
Management of essential thrombocytosis?
- Hydroxyurea (hydroxycarbamide) to reduce pl count
- IFN-a in younger patients
- low dose aspirin to reduce thrombotic risk
how to prevent haemorrhagic cystitis in those on cyclophosphamide?
Mesna (2-mercaptoethane sultanate sodium)
- binds to and neutralises acrolein
what type of cancer does cyclophosphamide increase risk of?
transitional cell carcinoma
a Leukaemoid reaction vs leukaemia causing high WBC
- high leucocyte alkaline phosphatase score
- toxic granulation (Dohle bodies) in the white cells
- left shift of neutrophils
Blood film features of hyposplenism e.g. post-splenectomy, coeliac disease?
target cells Howell-Jolly bodies Pappenheimer bodies siderotic granules acanthocytes
1st line management of idiopathic thrombocytopenic purpura?
oral prednisolone
management of idiopathic thrombocytopenic purpura?
oral pred (80% of patients respond)
- splenectomy if platelets < 30 after 3 months of steroid therapy
- IV immunoglobulins
- immunosuppressive drugs e.g. cyclophosphamide
features of acute intermittent porphyria?
- abdominal: abdominal pain, vomiting
- neurological: motor neuropathy
- psychiatric: e.g. depression
- hypertension and tachycardia common
genetics of acute intermittent porphyria?
- autosomal dominant
- defect in porphobilinogen deaminase
what are the toxic elements accumulated in acute intermittent porphyria?
delta aminolaevulinic acid
porphobilinogen
diagnosis of acute intermittent porphyria?
- urine: raised urinary porphobilinogen + urine turns deep red in sunlight
- assay of red cells for porphobilinogen deaminase
- raised serum levels of delta aminolaevulinic acid and porphobilinogen
lead poisoning: what is raised in urine?
coproporphyrin level
what drugs may precipitate haemolysis in G6PD deficiency?
- anti-malarials: primaquine
- ciprofloxacin
- sulph- group drugs: sulphonamides, sulphasalazine, sulfonylureas
pathophysiology of G6PD deficiency?
↓ G6PD → ↓ reduced NADPH → ↓ reduced glutathione → increased red cell susceptibility to oxidative stress
- reduced glutathione protects RBCs from oxidative damage
Features of G6PD deficiency?
- neonatal jaundice is often seen
- intravascular haemolysis
- gallstones are common
- splenomegaly may be present
- Heinz bodies on blood films. Bite and blister cells may also be seen
diagnosis of G6PD deficiency?
G6PD enzyme assay
- levels should be checked around 3 months after an acute episode of hemolysis to avoid false -ve result
IX of choice in CLL diagnosis?
Flow cytometry for immunophenotyping
- to reveal cell surface markers typical of CLL, including CD5, CD19 and CD20.
Defect in Chronic granulomatous disease?
lack of NADPH oxidase -> reduces ability of neutrophils to produce reactive oxygen species
-> susceptibility to catalase-positive bacteria e.g. staph aureus and fungi e.g. aspergillus
features of chronic granulomatous disease?
recurrent pneumonias and abscesses
diagnosis of chronic granulomatous disease?
abnormal dihydrorhodamine flow cytometry test
negative nitroblue-tetrazolium test
features of Chediak-Higashi syndrome?
- partial albinism
- peripheral neuropathy
- recurrent bacterial infections
- giant granules in neutrophils and platelets
defect in Chediak-Higashi syndrome
Microtubule polymerization defect which leads to a decrease in neutrophil phagocytosis
features of Leukocyte adhesion deficiency?
recurrent bacterial infections,
delay in umbilical sloughing,
absence of neutrophil/ pus at sites of infection
defect in Leukocyte Adhesion deficiency?
LAD1: deficiency of the (LFA-1) B-2 integrin subunit (CD18) of the Leukocyte adhesion molecule
Features of common variable immunodeficiency?
hypogammaglobulinaemia: Low IgG, IgE and IgA.
- FTT, recurrent infections, autoimmune and granulomatous diseases
- may predispose to lymphoma
Features of Bruton’s Agammaglobulinaemia?
- X linked recessive
- recurrent bacterial infections
- failed maturation of B cells with low IG (No antibodies)
Genetic defect of Bruton’s Agammaglobulinaemia?
X-linked defect in Bruton’s tyrosine kinase gene -> block in B cell development
Features of Selective IgA deficiency
- most common primary antibody deficiency
- recurrent gastro/ resp infections
- assoc w coeliac disease (may cause false -ve coeliac screen)
- severe reactions to blood transfusions (anti-IgA abs-> anaphylaxis)
Features of DiGeorge’s Syndrome?
CATCH - 22
Congenital heart disease - tetralogy of fallot
Abnormal facies - low set ears, cleft lip
Thymus - absent, low lvls of mature T cells -> recurrent viral/ fungal infections
Cleft palate
Hypocalcaemia
22q11.2 deletion
Defect in Wiskott-Aldrich syndrome?
Defect in WASP gene, X linked recessive
Features of Wiskott-Aldrich syndrome?
X linked recessive
- recurrent bacterial infections
- eczema
- thrombocytopenia
- Low IgM levels
- Increased risk of autoimmune disorders/ malignancy
CLL: Indications for treatment
- progressive marrow failure
- massive (>10 cm) or progressive lymphadenopathy
- massive (>6 cm) or progressive splenomegaly
- progressive lymphocytosis: > 50% increase over 2 months or lymphocyte doubling time < 6 months
- FLAWS: weight loss > 10% in previous 6 months, fever >38ºC for > 2 weeks, extreme fatigue, night sweats
- autoimmune cytopaenias e.g. ITP
CLL: Management if treatment is indicated
- fludarabine, cyclophosphamide and rituximab (FCR)
- Ibrutinib (2nd line)
1st line management of thrombotic thrombocytopenic purpura?
plasma exchange
Microscopy findings of Burkitt’s lymphoma?
‘starry sky’ appearance: lymphocyte sheets interspersed with macrophages containing dead apoptotic tumour cells
Mx of Burkitt’s lymphoma?
chemotherapy
what medication is given before chemotherapy to reduce risk of tumour lysis syndrome?
rasburicase (a recombinant version of urate oxidase, an enzyme which catalyses the conversion of uric acid to allantoin*)
what medication is given before chemotherapy to reduce risk of tumour lysis syndrome?
rasburicase (a recombinant version of urate oxidase, an enzyme which catalyses the conversion of uric acid to allantoin, which is 5-10x more soluble than uric acid)
Haptoglobin levels in haemolytic anaemia?
- LOW haptoglobin levels
Haptoglobin binds to free haemoglobin released from lysed erythrocytes. The complexes are then removed from the plasma by the hepatic reticulo-endothelial cells. Haptoglobin levels decrease if the rate of haemolysis is greater than the rate of haptoglobin production.
rare drug cause of B12 deficiency?
Metformin
MOA of cyclophosphamide?
alkylating agent- causes cross linking in DNA
gold standard investigation in Paroxysmal nocturnal haemoglobinuria?
flow cytometry of blood to detect low levels of CD59 and CD55
- has now replaced Ham’s test
features of Paroxysmal nocturnal haemoglobinuria?
- haemolytic anaemia +/- aplastic anaemia
- pancytopaenia may be present
- haemoglobinuria: classically dark-coloured urine in the morning (can occur throughout the day)
- thrombosis e.g. Budd-Chiari syndrome
Management of Paroxysmal nocturnal haemoglobinuria?
- blood product replacement
- anticoagulation
- eculizumab, a monoclonal antibody directed against terminal protein C5, being trialled
- stem cell transplantation
Cisplatin: what electrolyte abnormality as SE?
Hypomagnesaemia
Chemotherapy related N+V?
low risk - metoclopramide 1st line
high risk - 5HT3R antagonists eg. ondansetron +/- dexamethasone
Aflatoxin (produced by Aspergillus) - increased risk of which ca?
HCC
Aniline dyes - increased risk of which ca?
Bladder (Transitional cell ca)
Asbestos - increased risk of which ca?
Mestothelioma, bronchial ca
Nitrosamines - increased risk of which ca?
Oesophageal and gastric ca
Vinyl chloride - increased risk of which ca?
Hepatic angiosarcoma
Ix in multiple myeloma?
- monoclonal proteins in serum and urine (bence jones proteins)
- Whole body MRI
- XR: “rain drop skull”
Diagnostic criteria for multiple myeloma?
1 major, 1 minor OR 3 minor
Major criteria
- Plasmacytoma
- 30% plasma cells in a bone marrow sample
- Elevated levels of M protein in the blood or urine
Minor criteria
- 10% to 30% plasma cells in a bone marrow sample.
- Minor elevations in the level of M protein in the blood or urine.
- Osteolytic lesions.
- Low levels of antibodies (not produced by the cancer cells) in the blood.
MX of antiphospholipid syndrome in pregnancy?
aspirin + LMWH (until 34/40 gestation)