Haematology Flashcards
What 2 groups can macrocytic anaemia be split into and what are examples of each?
- megaloblastic: B12 deficiency (pernicious), folate deficiency, drugs (sulfonamides), gastrectomy, terminal ileum resection
- normoblastic: liver disease, alcoholism, hypothyroidism, myelodysplasia, anticonvulsants
What are 5 blood test abnormalities that may be seen in anti-phospholipid syndrome?
- Anti-cardiolipin antibodies
- Lupus anticoagulant
- Anti beta2 glycoprotein 1 antibody
- Prolonged APTT (paradoxical)
- Low platelets
What are the criteria for diagnosing hereditary haemorrhagic telangiectasia?
2 criteria - possible diagnosis
3 or more - definite diagnosis
the criteria:
1. epistaxis
2. telangiectases multiple at characteristic sites (lips, oral cavity, fingers, nose)
3. visceral lesions e.g. GI telangiectasia (+/- bleeding), pulmonary AVMs, hepatic AVM, cerebral AVM, spinal AVM
4. family history first-degree relative with HHT
What is the key histological finding in Hodgkin’s lymphoma?
Reed-Sternberg cells (cells of B cell origin, unable to express antibodies)
What are the 5 types of Hodkin’s lymphoma and which has a different treatment paradigm?
- nodular sclerosis
- mixed cellularity
- lymphocyte-depleted
- lymphocyte-rich
- nodular lymphocyte predominant Hodgkin disease (different treatment, unique entity)
What is Pel-Ebstein fever in Hodgkin’s lymphoma?
high fever for 1-2 weeks followed by afebrile period of 1-2 weeks
What is alcohol induced pain with lymphadenopathy specific for?
Hodgkin’s disease
What system is sued to stage Hodgkin’s disease?
Ann Arbor system
What is the treatment for Hodgkin’s lymphoma?
radiotherapy and/or chemotherapy
What is the commonest inherited theombophilia?
Factor V Leiden
What are 5 examples of inherited thrombiphilias?
- Factor V Leiden
- Prothrombin gene mutation
- Anthrombin III deficiency
- Protein S deficiency
- Protein C deficiency
What is an example of an acquired thrombophilia?
Antiphospholipid syndrome
What are 4 features of polycythaemia?
- Pruritus - particularly after warm bath
- Ruddy complexion
- Gout
- Peptic ulcer disease
What is the commonest secondary cause of antiphospholipid syndrome?
SLE
Why does antiphospholipid syndrome cause a paradoxical rise in APTT?
ex-vivo reaction of lupus anticoagulant antibodies with phospholipids involved in the coagulation cascade
What are 4 diseases associated with anti-phospholipid syndrome?
- SLE
- other autoimmune disorders
- lymphoproliferative disorders
- phenothiazindes (rare)
What is a key dermatological manifestation of antiphospholipid syndrome?
livedo reticularis
What is the primary thromboprophylaxis management for antiphospholipid syndrome?
low-dose aspirin
What is the secondary thromboprophylaxis given in antiphospholipid syndrome?
- initial VTE event: lifelong warfarin, target INR 2-3
- recurrent VTE: lifelong warfarin; if whilst taking warfarin add low dose aspirin, target 3-4
- arterial thrombosis: lifelong warfarin target INR 2-3
What is immune (idiopathic) thrombocytopenic purpura?
immune-mediated reduction in platelet count; antibodies are directed against glycoprotein IIb/IIIa or Ib-V-IX complex
What type of hypersensitivity reaction is immune thrombotuopenic purpura?
type II
What are the key features of immune thrombocytopenia in children?
- bruising, petechial or purpuric rash, bleeding less common (if occurs - epistaxis or gingival bleeding)
- more acute than in adult
What will investigations show in immune thrombocytopenic purpura in children in children?
FBC - isolated thrombocytopenia
bone marrow examination - only required if atypical features e.g. LN enlargement/splenomegaly, high/low WCC, failure to resolve/respond to treatment
What is the management of immune thrombocytopenic purpura in chidlren?
- resolves spontaneously in 80% of children within 6 months with or without treatment
- avoid activties that may result in trauma e.g. team sports
- if platelet count <10 or significant bleeding, options: oral/IV corticosteroid, IVIG, platelet transfusion in emergency
What should be administered during cardiac arrest if pulmonary embolism is suspected & how does this cahnge the CPR algorithm?
thrombolytic drugs e.g. alteplase - if given, CPR should be continued for extended period 60-90 min
What is the classical genetic abnormality in chronic myeloid leukaemia?
- Philadelphia chromosome
- = translocation between long arm of chromosome 9 and 22
- results in ABL proto-oncogene being fused with BCR gene - BCR-ABL gene codes for fusion protein with increased tyrosine kinase activity
At what age does chronic myeloid leukaemia present?
60-70 years
What are the key presenting clinical features of chronic myeloid leukaemia?
- anaemia: lethargy
- weight loss and sweating
- splenomegaly → abdo discomfort
- increase in granulocytes at different stages of maturation +/- thrombocytosis
- decreased leukocyte alkaline phosphatase
- may undergo blast transformation (AML in 80%, ALL in 20%)
What is the first-line management of chronic myeloid leukaemia?
imatinib - inhibits tyrosine kinase associated with BCR-ABL defect
What are 4 options for treatment of chronic myeloid leukaemia?
- imatinib
- hydroxyurea
- interferon-alpha
- allogenic bone marrow transplant
What are 2 types of acute leukaemia and when do they classically present?
- Acute myeloid leukaemia - adulthood
- Acute lymphoblastic leukaemia - childhood (2-5 years)
What is the most common type of childhood malignancy?
acute lymphoblastic leukaemia (ALL)
What are the clinical features of acute lymphoblastic leukaemia?
- anaemia - lethargy and pallor
- neutrophenia - infections
- thrombocytopenia - bruising, petechiae
- bone pain
- splenomegaly
- hepatosplenomegaly
- fever
- testicular swelling
What are 3 types of acute lymphoblastic leukaemia?
- common ALL (75%) - CD10 present, pre-B phenotype
- T-cell ALL
- B-cell ALL
What are 5 poor prognostic factors for ALL?
- age < 2 years or >10 years
- WBC <20 at diagnosis
- T or B cell surface markers
- non-Caucasian
- male sex
Which patient group does haemolytic uraemic syndrome usually present in?
young children
What is the triad of symptoms seen in haemolytic uraemic syndrome?
- acute kidney injury
- microangiopathic haemolytic anaemia
- thrombocytopenia
What is the class cause of primary haemolytic uraemic syndrome?
- Shiga toxin-producing E coli (STEC) 0157:H7
In addition to STEC, what are 3 other causes of secondary haemolytic uraemic syndrome?
- pneumococcal infection
- HIV
- SLE, drugs, cancer
What causes primary (atypical) HUS?
complement dysregulation
What are 3 investigations to perform in haemolytic uraemic syndrome?
- FBC - anaemia (microangiopathic haemolytic anaemia), thrombocytopenia, fragmented blood film
- U+E - AKI
- stool culture - PCR for Shiga toxins, looking for STEC
What will blood film show in haemolytic uraemic syndrome?
fragmented: schistocytes and helmet cells
What will Coombs test show in haemolytic uraemic syndrome?
negative
What is the management of haemolytic uraemic syndrome?
- supportive - fluids, blood transfusion, dialysis if required
- plasma exchanged in severe cases NOT associated with diarrhoea
- eculizumab in adult atypical HUS
What are 4 types of crises in sickle cell anaemia?
- thrombotic a.k.a. ‘vaso-occlusive’ ‘painful crises’
- acute chest syndrome
- anaemic aplastic or sequestration
- infection
What are 3 things that can precipitate a vaso-occlusive / thrombotic sickle cell crisis?
- infection
- dehydration
- deoxygenation e.g. high altitude
What are 5 sites where infarction can occur in a sickle cell vaso-occlusive (thrombotic) crisis?
- avascular necrosis of hip
- hand-foot syndrome (children)
- lungs
- spleen
- brain
What is acute chest syndrome in sickle cell disease?
vaso-occlusion within the pulmonary microvasculature leading to infarction in the lung parenchuma
What is the management of acute chest syndrome in sickle cell disease?
- pain relief
- respiratory support e.g. oxygen therapy
- antibiotics
- transfusion - improves oxygenation
What causes aplastic crises in sickle cell disease?
infection with parvovirus
How will aplastic crises in sickle cell disease manifest on blood tests?
- sudden fall in Hb
- reduced reticulocyte count (bone marrow suppression)
What is a sequestration crisis in sickle cell disease?
- sickling within organs such as spleen or lungs causing pooling of blood with worsening of the anaemia
- may present with splenomegaly, abdominal pain, clinical anaemia
How will a sequestration crisis in sickle cell disease manifest on blood tests?
worsening of anaemia, INCREASED reticulocyte count
How can aplastic and sequestration crises be differentiated in sickle cell disease, on the basis of blood tests?
reticulocyte count increased in sequestration, reduced in aplastic
What are 6 PRC transfusion reactions?
- Non-haemolytic febrile reaction
- Minor allergic reaction
- Anaphylaxis
- Acute haemolytic reaction
- Transfusion-associated circulatory overload (TACO)
- Transfusion-related acute lung injury (TRALI)
What are the features of non-haemolytic febrile reaction in response to blood transfusion?
fever, chills
10-30% caused by platelet transfusion
What is the management of a non-haemolytic febrile reaction?
slow or stop transfusion, paracetamol, monitor
What is thought to cause non-haemolytic febrile transfusion reaction?
HLA antibodies reacting with white cell fragments in the blood product and cytokines that have leaked from the blood cell durting storage - often due to sensitisation by previous pregnancies / transfusions
What is thought to cause minor allergic reactions to blood transfusion?
foreign plasma proteins
What are the features of a minor allergic reaction to blood transfusion?
pruritis, urticaria
What is the management of minor allergic reaction to blood transfusion?
- temporarily stop transfusion
- antihistamine
- monitor
- once symptoms resolve, transfusion may be continued
What can cause anaphylaxis in response to blood transfusion?
patients with IgA deficiency who have anti-IgA antibodies
What is the management of anaphylaxis in response to blood transfusion?
permanently discontinue - administer IM adrenaline - supportive care; antihistamine, steroids and bronchodilators, IVF
What causes an acute haemolytic transfusion reaction?
mismatch of blood group (ABO) causng massive intravascular haemolysis - usually result of red blood cell destruction by IgM type antibodies
How quickly do acute haemolytic transfusion reaction symptoms develop and what are they?
- within minutes
- fever, abdominal / chest pain, agitation, hypotension
What is the management of acute haemolytic transfusion reaction?
- stop transfusion
- confirm diagnosis - check patient ID / blood product
- send blood for direct Coomns test, repeat typing and cross-matching
- IVF resuscitation
- inform lab
What are 2 possible complications of acute haemolytic transfusion reaction?
- intravascular coagulation
- renal failure
What are 2 things that can pre-dispose to transfusion-associated circulatory overload?
- excessive rate of transfusion
- pre-exisitng heart failure
What is a key difference in TACO that is not seen in TRALI?
patients may be hypertensive in TACO
What is the management of TACO?
slow or stop transfusion
consider IV loop diuretic and O2
What is transfusion-related acute lung injury (TRALI)?
- non-cardiogenic pulmonary oedema
- thought secondary to increased vascular permeabiliy caused by host neutrophils
- activated by substances in donated blood
- develop hgypoxaemia / acute respiratory distress syndrome
How quickly does TRALI develop?
within 6 hours of transfusion
What are 4 key features of TRALI?
- hypoxia
- pulmonary infiltrates on CXR
- fever
- hypotension
What is the management of TRALI?
stop transfusion, oxygen, supportive care
What are 4 ways that the risk of vCJD from blood transfusion has been reduced?
- leucodepletion to reduce vCJD infectivity
- plasma derivated have been fractionated from imported plasma (not UK donors)
- FFP for children / certain adult groups imported
- recipients of blood transfusion excluded from donating blood
What are 4 secondary causes of polycythaemia which are due to excessive erythropoietin?
- cerebellar haemangioma
- hypernephroma
- hepatoma
- uterine fibroids
How can you differentiate between true (primary or secondary) polycythaemia and relative polycythaemia (dehydration / stress)?
red cell mass studies are sometimes used. In true polycythaemia the total red cell mass in males > 35 ml/kg and in women > 32 ml/kg (not in relative PC)
What are 2 relative causes of polycythaemia?
- dehydration
- stress (Gaisbock syndrome)
What is primary polycythaemia called?
polycythaemia rubra vera
What are 4 secondary causes of polycythaemia?
- COPD
- altitude
- OSA
- excessive EPO
What is a cause of episodic RUQ pain in a patient with hereditary spherocytosis?
biliary colic - chronic haemolysis -> gallstone formation (differential - splenic rupture)
What is the inheritance pattern of hereditary spherocytosis?
autosomal dominant
What are 7 aspects of the presentation of hereditary spherocytosis?
- failure to thrive
- jaundice
- gallstones
- splenomegaly
- aplastic crisis precipitated by parvovirus infection
- degree of haemolysis variable
- MCHC elevated
When are no additional tests required for a diagnosis of hereditary spherocytosis?
- patients with family history of HS
- typical clinical features
- typical laboratory investigations: spherocytes, raised mean corpuscular haemoglobin concentration (MCHC), high reticuloctes
If diagnosis is equivocal based on initial presentation and lab tests, what is the diagnostic test for hereditary spherocytosis?
EMA binding test and cryohaemolysis test
What is the method of choice for diagnosing hereditary spherocytosis with atypical presentations?
electrophoresis analysis of erythrocyte membranes
What is the management of an acute haemolytic crisis in hereditary spherocytosis?
supportive, transfuse if necessary
What are 2 aspects of the long term management of hereditary spherocytosis?
- folate replacement
- splenectomy
Which region of the world is hereditary spherocytosis more common?
North European
What are 4 types of Hodgkin’s lymphoma and their relative frequencies?
- Nodular sclerosing - 70% (commonest)
- Mixed cellularity (20%)
- Lymphocyte predominant (5%)
- Lymphocyte depleted (rare)
What is the order of prognosis of the 4 types of Hodgkin’s lymphoma from best to worst?
- Best: Lymphocyte predominant
- Good: nodular sclerosing
- Good: mixed cellularity
- Worst: lymphocyte depleted
Which type of Hodgkin’s lymphoma is associated with lacunar cells?
nodular sclerosing
Which type of Hodgkin’s lymphoma is associated with a large number of Reed-Sternberg cells?
mixed cellularity
What symptoms imply a poor prognosis in Hodgkin’s lymphoma?
B symptoms - weight loss >10% in last 6 months, fever >38, night sweats
What are 7 factors associated with a poor prongosis in Hodgkin’s lymphoma other than b symptoms?
- age > 45 years
- stage IV disease
- Hb <10.5
- lymphocytes < 600 or 8%
- male
- albumin < 40
- WCC < 15 000
Of blood transfusion and exchange transfusion in sickle cell crises, which can rapidly reduce the percentage of Hb S containing cells?
exchange transfusion (not blood)
When should you admit patients with features of a sickle cell crisis?
- all children with fever - particularly if unexplained
- low threshold for all children
- temperature over 38
- any chest symptoms
What are 4 blood test findings in iron deficiency anaemia?
- low ferritin (can be raised during inflammatory states)
- increased total iron binding capacity (TIBC)
- low serum iron
- reduced transferrin saturation (but increased transferrin)
What type of anaemia is IDA?
hypochromic microcytic anaemia
For how long should patients continue taking iron after iron deficiency has been corrected?
3 months
How can you differentiate between CLL and CML?
- chronic lymphocytic leukaemia - lymphocytosis with mature lymphocytes and smudge cells on peripheral smear
- chronic myeloid leukaemia - increased numbers of granulocytes at all stages of development, splenomegaly + high platelets
What is the inheritance pattern of beta-thalassaemia?
autosomal recessive
What are 2 features on blood tests of beta-thalassaemia trait?
- mild hypochromic, microcytic anaemia - microcytosis disproportionate to anaemia
- HbA2 raised (>3.5%)
What is the mechanism of action of dabigatran?
direct thrombin inhibitor
What is the reversal agent for dabigatran?
idarucizumab
Which drugs can andexanet alfa be used as the reversal agent?
rivaroxaban + apixaban
What is the mechanism of action of rivaroxaban / apixaban / edoxaban?
direct factor Xa inhibitor
What is the excretion of different DOACs?
- dabigatran: renal
- rivaroxaban: liver
- apixaban: faecal
- edoxaban: faecal
At what partial pressure of oxygen do patients with HbAS (one normal, one abnormal chain) RBCs sickle?
2.5-4 kPa
At what partial pressure of oxygen do patients with HbSS (two abnormal chains) RBCs sickle?
pO2 5-6 kPa
How is a definitive diagnosis of sickle cell disease made?
haemoglobin electrophoresis
What are 2 causes of benign paraproteinaemia?
- monoclonal gammopathy of undetermined significance (MGUS)
- transient paraproteinaemia (e.g. after infection)
What are 4 malignant causes of paraproteinaemia?
- multiple myeloma
- Waldenstrom macroglobulinaemia
- primary amyloidosis
- B-cell lymphoproliferative disorders e.g. CLL, non-Hodgkin lymphoma
What are 5 clinical features of paraproteinaemia?
- hyperviscosity syndrome
- neuropathy e.g. sensory, motor, autonomic
- renal dysfunction
- haematologic abnormalities e.g. anaemia, thrombocytopenia, leukopenia
- bone pain or pathologic fractures
What are 3 key aspects of the management of polycythaemia vera?
- aspirin - reduces risk of thrombotic events
- venesection - first line to normalise Hb
- chemotherapy - hydroxyurea, phosphorus-32 therapy
What are 2 options for chemotherapy for polycythaemia rubra vera?
- hydroxyurea
- phosphorus-32 therapy
What are 3 key risks in polycythaemia vera?
- thrombotic events
- progression to myelofibrosis
- progression to acute leukaemia (chemotherapy increases risk)
What are 5 features of post-thrombotic syndrome after DVT?
- painful, heavy calves
- pruritus
- swelling
- varicose veins
- venous ulceration
What is the advice regarding compression stockings and post-thrombotic syndrome?
NICE advise do not offer elastic compression stockings to prevent PTS or VTE recurrence - but recommended once PTS has developed
What are 5 causes of microcytic anaemia?
- iron-deficiency anaemia
- thalassaemia
- congenital sideroblastic anaemia
- anaemia of chronic disease (but more commonly normocytic)
- lead poisoning
What does normal Hb with microcytosis raise the possibility of?
polycythaemia rubra vera
In which condition can a microcytosis be disproportionate to the anaemia?
beta thalassaemia
In which condition are ‘tear drop’ poikilocytes generally seen?
myelofibrosis (flat, elongated RBCs)
In which condition are smear cells generally seen on a blood film?
chronic lymphocytic leukaemia (CLL)
In what 2 conditions are spherocytes seen on a blood film?
- hereditary spherocytosis
- autoimmune haemolytic anaemia
What are 2 conditions in which target cells (RBCs) are seen on blood film?
- iron-deficiency anaemia
- hyposplenism
In which condition are Auer rods classically seen?
acute promyelocytic leukaemia
What is the more common form of acute leukaemia in adults?
acute myeloid leukaemia
What are 5 features of acute myeloid leukaemia?
- Anaemia
- Neutropenia - may be high WCCs, low functioning neutrophils
- thrombocytopenia + bleeding
- splenomegaly
- bone pain
What are 3 poor prognostic features in AML?
- > 60 years
- > 20% blasts after first course of chemo
- cytogenetics: deletions of chromosome 5 or 7
What causes acute promyelocytic leukaemia M3 genetically?
associated with t(15;17), fusion of PML and RAR-alpha genes
What is the prognosis of acute promyelocytic leukaemia M3 compared with other AML?
good prognosis
What age group is commonly affected by acute promeylocytic leukaemia M3?
younger than other AML types - avg 25 years
What is often seen at presentation of Acute promyelocytic leukaemia M3?
DIC or thrombocytopenia
What classification is used for AML?
French-American-British (FAB) classification, M0-M7
When does WHO recommend platelet transfusion is given?
platelet count < 30 with clinically significant bleeding (haematemesis, melaena, prolonged epistaxis)
When is a platelet threshold > 30 used?
maximum <100 for patients with severe bleeding or critical sites e.g. CNS
Which type of blood product has the highest risk of bacterial contamination?
platelet transfusion
What are the platelet thresholds that are aimed for before surgery / invasive procedure?
- most patients: > 50
- high risk of bleeding: 50-75
- surgery at critical site: > 100
What is the target level of platelets in someone without active bleeding or any planned procedure?
threshold of 10 (except if platelet transfusion CI / there are alternative treatments)
What are 4 conditions when platelet transfusion should not be performed?
- chronic bone marrow failure
- autoimmune thrombocytopenia
- heparin-induced thrombocytopenia
- thrombotic thrombocytopenic purpura
What is the most common inherited bleeding disorder?
von Willebrand’s disease
What is the inheritance pattern of von Willebrand’s disease?
most commonly autosomal dominant (type 3, total lack of vWF = autosomal recessive)
What type of bleeding does von Willebrand’s disease cause?
behaves like platelet disorder - epistaxis and menorrhagia common, haemarthroses and muscle haematomas rare
What is the role of von Willebrand factor?
large glycoprotein which forms massive multimers; promotes platelet adhesion to damaged endothelium. also carrier molecule for factor VIII
What are 3 types of von Willebrand’s disease?
- type 1: partial reduction in vWF (80% of patients)
- type 2: abnormal form of vWF
- type 3: total lack of vWF
What are 4 blood test findings in von Willebrand’s disease?
- prolonged bleeding time
- prolonged APTT
- factor VIII levels may be moderately reduced
- defective platelet aggregation with ristocetin
What are 3 aspects of the treatment of von Willebrand’s disease?
- TXA - mild bleeding
- desmopressin (DDAVP) - raises vWF levels by induced release from Weibel-Palade bodies in endothelial cells
- factor VIII ceoncentrate
What is seen on a blood film in DIC and why?
schistocytes - microangiopathic haemolytic anaemia
What are 4 things seen on FBC / clotting profile in DIC?
- reduced platelets
- reduced fibrinogen
- raised PT and APTT
- raised fibrinogen degradation products
How can you distinguish between liver failure and DIC as causes for coagulopathy on blood tests?
- liver failure: all clotting factors low except factor VIII, which is supranormal
- DIC: all clotting factors depleted
What are 3 causes why there is a paradoxical increased risk of venous thromboembolism in liver failure despite prolonged PT and APTT?
- supranormal levels of factor VIII
- reduced synthesis of protein c and protein s (vitamin K dependent)
- reduced anti-thrombin synthesis (non-vtamin K dependent)
What is the management with antiplatlets/anticoagulation in someone with a history of stable CVD + indication for anticoagulation e.g. AF?
anticoagulant monotherapy without antiplatelets
What is the antiplatelet/anticoagulant management of a patient post-ACS / PCI?
- initially give 2 antiplatelets + 1 anticoagulant for 4 weeks - 6 months
- then 1 antiplatelet + 1 anticoagulant for 12 months
What is anti-streptolysin O antibody associated with in children?
Henoch-Schonlein purpura