Haemophilia

Summary of Haemophilias

Haemophilia definition: condition causing bleeding: 

1. Genetic 

   1. 1. Haemophilia A & B

      2. Von Willebrand Disease

2. Acquired 

   1. Secondary Causes of Bleeding

   2. Acquired Haemophilia (AH) - autoimmune 

Von WilleBrand Disease

• Commonest inherited bleeding disorder

• Mechanism of action: low levels of Von Willebrand Factor is unable to activate clotting ability of factor VIII

• Presents with platelet bleeding: bleeding gums, menorrhagia, bleeding ++ after minor procedures

• Management: desmopressin, tranexamic acid

Haemophilia A & B

• Haemophilia A- factor 8, 

• Haemophilia B- factor 9 (Christmas disease)

• X linked recessive

• 2nd most common bleeding disorder

• Presents with coagulopathic bleeding: hemarthrosis, normal PT and APTT

Acquired Haemophilia

• Acquired haemophlia is a rare autoimmune condition, associated with anti-factor VIII IgG antibodies

• Cause

  • Idiopathic (majority)

  • Secondary:

    •  Rheumatoid Arthritis, IBD

    • Drugs- phenytoin

• Investigations: prolonged PT & APTT

• Management: 

  • Low level of antibodies: factor VIII replacement

  • Bleeding: corticosteroids +- ciclosporin 

  • Refractory bleeding: recombinant factor VII

Secondary Causes of Bleeding 

• Iatrogenic: anticoagulants: DOACs, warfarin, heparin, fondaparinux; antiplatelets: clopidogrel > aspirin

• Thrombocytopenia: ITP, TTP, HUS, HIT, DIC

• Hypocalcemia- calcium integral to clotting cascade

• Sepsis/ infections, malignancy (particularly haematological)

• Trauma

Page written in 2024.