Clinical Haematology Flashcards

(40 cards)

1
Q

What is Pancytopenia?

A

Condition characterised by a decrease in all three blood cell types : RBCs, WBCs, Platelets

Patients may present with symptoms related to anaemia, bleeding or infections

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2
Q

What are the potential causes of Pancytopenia?

A
  • Most common underlying causes of pancytopenia are bone marrow disorders such as aplastic anaemia or myelodysplastic syndrome
  • Medications, such as chemo or immunosuppressants
  • Drug interaction between azathioprine and allopurinol can cause bone marrow suppression
  • Nutritional deficiencies such as B12 or Folate
  • Autoimmune disorders, such as SLE or RA
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3
Q

H&E of Pancytopenia

A

Symptoms of Anaemia
- Fatigue
- Weakness
- Pallor
- SOB

Symptoms of low platelets + WBCs
- Easy bruising
- Bleeding gums
- Frequent infections

Exam may reveal pallor, petechiae or purpura

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4
Q

Investigations for Pancytopenia

A

FBC is first-line and will reveal low levels of all blood cell types

Bone marrow biopsy may be necessary to determine underlying cause

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5
Q

Management of Pancytopenia

A
  • Treat underlying cause
  • In cases of severe pancytopenia, blood transfusions and/or bone marrow transplant may be needed
  • Referral to specialist for further evaluation and management
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6
Q

What is Polycythaemia?

A

Condition where body produces too many RBCs
OR
There is a relative excess of RBCs

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7
Q

What are the causes of Polycythaemia?

A

Primary: (Polycythaemia rubra vera)

Relative causes:
- dehydration
- stress (Gaisbock syndrome)

Secondary:
- COPD
- Altitude
- Obstructive sleep apnoea
- Excessive EPO (cerebellar haemangioma, hypernephroma, hepatoma, uterine fibroids)

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8
Q

How can true and relative Polycythaemia be distinguished?

A

To differentiate between true (primary or secondary) polycythaemia and relative polycythaemia 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

  • uterine fibroids may cause menorrhagia which in turn leads to blood loss - polycythaemia is rarely a clinical problem
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9
Q

What is Polycythaemia rubra vera?

A
  • Mutation in JAK2 gene
  • Too many RBCs made by bone marrow
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10
Q

H&E of Polycythaemia

A
  • Itchiness (especially after warm bath)
  • Burning/tingling in hands
  • Blurry vision
  • Headaches
  • Plethoric - red nose
  • Splenomegaly
  • Thrombosis
  • Gout
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11
Q

Investigations of Polycythaemia

A
  • Examine for DVT
  • FBC
    • high Hb
    • Hct >0.52 in males and >0.48 in females is DIAGNOSTIC
  • EPO levels (low in primary and high in EPO tumour)
  • CXR, Renal scan
  • Bone Marrow biopsy
  • Gene panel for JAK2 Mutation
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12
Q

Management of Polycythaemia

A
  • First line - Venesection (maintain Hct <0.45)
  • Aspirin
  • Hydroxycarbamide if high risk of thrombosis
  • JAK2 inhibitors
  • Annual follow ups to check for signs of myelofibrosis
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13
Q

What is Haemophilia A?

A

Factor 8 deficiency

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14
Q

What is Haemophilia B?

A

Factor 9 deficiency

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15
Q

Genetics of Haemophilia

A

X-linked recessive disorder

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16
Q

H&E of Haemophilia

A
  • Haemarthrosis (bleeding into joints - swollen and painful)
  • Haematoma

Severe will present within 2 years and bleeding into joints

Milder cases will present later in life after surgery or trauma

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17
Q

Investigations for Haemophilia

A

Blood tests

  • Prolonged APTT (factors 8 and 9 are part of the intrinsic pathway)
  • Factor assay
  • PT/INR and platelet count will be normal
18
Q

Management of Haemophilia

A
  • Avoid high impact sports
  • Avoid blood thinning medication
  • Desmopressin - release of stored factor 8 and VWF
  • Recombinant factor 8/9
19
Q

What is Disseminated Intravascular Coagulation?

A

DIC

  • Widespread activation of clotting leading to clotting factors and platelets being consumed = increased risk of bleeding
  • Tissue factor mediated
  • Risk factors include malignancy, sepsis, trauma/surgery/burns, pregnancy complications
20
Q

Investigations of DIC

A

Bloods
- Low platelets and fibrinogen
- Increased fibrin degradation products
- Long PT and APTT
- Schistocytes
- High D-dimer

21
Q

Management of DIC

A
  • Treat cause
  • Give transfusions
  • Up to 4 units of FFP and 10 units of cryoprecipitate whilst waiting for coagulation studies
22
Q

What is Essential Thrombocytopaenia?

A

Proliferation of megakaryocytes and overproduction of platelets

Mutation in JAK2 gene

23
Q

H&E of Essential thrombocythaemia

A

Hyperviscosity
- Headaches, dizziness
- Arterial and venous thrombosis

Splenomegaly

Haemorrhage

Burning sensation in hand

24
Q

Investigations for Essential thrombocythaemia

A

Examine for DVT

Bloods
- FBC = raised platelets
- CRP/ESR to rule out infection/inflammation

Bone marrow biopsy
- inc. megakaryocytes

Gene panel for JAK2 mutation

25
Management of Essential thrombocythaemia
- Low dose aspirin - Hydroxycarbamide (hydroxyurea)
26
What is Polycythaemia rubra vera?
Too many RBCs made by bone marrow Mutation in JAK2 gene
27
H&E of Polycythaemia rubra vera
- Itchiness especially after warm bath - Hyperviscosity = headaches, dizziness, thrombosis - Splenomegaly - Haemorrhage due to abnormal platelet function - Burning/tingling in hands - Blurry vision - Plethoric - red nose - Gout
28
Investigations for Polycythaemia rubra vera
- Examine for DVT - FBC = high Hb, Hct > 0.52 M, > 0.48 F is DIAGNOSTIC - Low EPO level (high in EPO secreting tumour) - CXR, Renal scan - Bone marrow biopsy - Gene panel for JAK2 mutation
29
Management of Polycythaemia rubra vera
- Venesection (maintain Hct < 0.45) - Aspirin - Hydroxycarbamide if high risk of thrombosis - JAK2 inhibitors - Annual follow up to check for signs of Acute leukaemia or myelofibrosis
30
What is Myelofibrosis?
Clonal proliferation of stem cells = cytokine release = fibrosis Bone marrow failure JAK2 mutation RF = polycythaemia rubra vera and essential thrombocytopaenia
31
H&E of Myelofibrosis
- Usually elderly - Pancytopenia - Massive splenomegaly - Can present with Budd-Chiari syndrome - portal vein thrombosis
32
Investigations for Myelofibrosis
- Bone marrow aspiration = dry tap = trephine biopsy - Blood film = tear drop poikilocytes (dacrocytes) - Molecular tests for JAK2 - FBC = anaemia, high urate, high LDH
33
Management of Myelofibrosis
- Support with blood products - JAK2 inhibitors - Stem cell transplant
34
Causes of Hyposplenism
- Splenectomy - Sickle-cell - Coeliac disease, dermatitis herpetiformis - Graves’ - SLE - Amyloid
35
Features of Hyposplenism
- Howell-Jolly bodies - Siderocytes - Radionucleotide labelled red cell scan
36
Management after Splenectomy
- Pneumococcal vaccine, haemophilus B, meningococcal type C vaccinations 2 weeks before or after procedure - Annual influenza vaccination - Antibiotic prophylaxis for post-splenectomy sepsis - Penicillin V 500mg BD - Amoxicillin 250mg BD
37
Indications for Splenectomy
Trauma : 1/4 are iatrogenic Spontaneous rupture : EBV Hypersplenism : spherocytosis or elliptocytosis etc Malignancy : lymphoma or leukaemia Splenic cysts, hyatid cysts or splenic abscess
38
Complications of Splenectomy
Haemorrhage Pancreatic fistula Thrombocytosis : prophylactic aspirin Encapsulated bacteria infection e.g. Strep. pneumoniae, Haemophilus influenzae and Neisseria meningitidis
39
Post-splenectomy changes
Platelets will rise first (therefore ITP given after splenic artery clamped) Blood film will change over following weeks, Howell-Jolly bodies will appear so will Target cells and Pappenheimer bodies Inc. risk of sepsis so prophylactic Abx and vaccine should be given
40
Post-splenectomy Sepsis
Typically occurs with encapsulated organisms Opsonisation occurs but then not recognised Usually form dog bites