Thrombocytopenia

Question 1

Causes

Answer 1

• Problems with production:
  
  • Sepsis
  • B12 or folate deficiency
  • Liver failure causing thrombopoietin production
  • Leukaemia
  • MDS
• Problems with destruction:
  
  • Medications (sodium valproate, methotrexate, irotretinoin, antihistamines, PPIs)
  • Alcohol
  • Immune thrombocytopenic purpura
  • Thrombotic induced thrombocytopenia
  • Heparin induced thrombocytopenia
  • HUS

Question 2

Immune thrombocytopenia purpura (ITP)

Answer 2

• Antibodies are created against platelets
• Management includes:
  
  • Prednisolone
  • IVIG
  • Riturimab
  • Splenectomy

Question 3

Thrombotic thrombocytopenia purpura

Answer 3

• Blood clots develop throughout the small vessels using up platelets
• Problem with protein ADAMTS13 that normally inactivates vWF and reduces platelet adhesion to vessel walls and clot formation
• Treatment involves:
  
  • Plasma exchange
  • Steroids
  • Rituximab

Question 4

Heparin induced thrombocytopenia (HIT)

Answer 4

• Development of antibodies against platelets in response to heparin
• Target protein on platelets called platelet factor 4
• HIT antibodies bind to platelets and activate clotting mechanisms leading to a hypercoagulable state
• Management is stopping heparin