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