Bleeding disorders
Causes:
Haemophilia A and B - Genetic disorders caused by deficiencies in clotting factors VIII (Haemophilia A) and IX (Haemophilia B).
Thrombocytopaenia - A reduction in platelet count, with Immune Thrombocytopaenic Purpura (ITP) being the most common form.
Von Willebrand Disease (vWD) - A hereditary condition affecting the von Willebrand factor, which is involved in platelet adhesion and binds factor VIII in the clotting cascade.
Vitamin Deficiencies - Deficiencies in vitamins A8 and B9 (factors VIII and IX) can also contribute to clotting issues.
Pathophysiology:
Symptoms:
Easy bruising (purpura)
Bleeding from gums and nosebleeds (epistaxis)
Prolonged bleeding from small cuts
Blood in urine (haematuria)
Heavy menstrual bleeding (menorrhagia)
Joint bleeds (haemarthrosis), often seen in haemophilia
Postoperative bleeding
Differential Diagnosis:
Liver disease (affects clotting factor production)
Vitamin K deficiency (required for clotting factor synthesis)
Disseminated Intravascular Coagulation (DIC)
Investigations:
Haemophilia Screen - Measures levels of factor VIII and factor IX to diagnose haemophilia A and B.
Von Willebrand Screen - Includes tests for von Willebrand factor antigen, factor VIII activity, and ristocetin cofactor activity to diagnose vWD.
Platelet Count - Helps assess for thrombocytopaenia. Diagnosis of ITP is usually by exclusion.
Management:
Replacement Therapy - Infusion of deficient clotting factors (e.g., factor VIII or IX for haemophilia).
Desmopressin (DDAVP) - For mild cases of vWD and haemophilia A; it helps to release stored factor VIII and von Willebrand factor.
Antifibrinolytics (e.g., Tranexamic Acid) - Used to reduce bleeding during surgery or after injury.
Platelet Transfusions - In cases of severe thrombocytopaenia or bleeding episodes.
Hormonal Therapy - For managing menorrhagia in patients with bleeding disorders.
Complications:
Chronic joint damage due to recurrent haemarthrosis in haemophilia
Increased risk of bleeding complications during surgical or dental procedures
Anaemia due to chronic blood loss
Prognosis:
With appropriate management and preventive care, individuals with bleeding disorders can maintain a good quality of life. However, they remain at risk for bleeding complications, especially in cases of trauma or surgery.
Hereditary thrombophilia
Note: Von Willebrand Disease (vWD)
Prevalence: vWD is the most common inherited bleeding disorder, affecting around 0.1% (1 in 1,000) of the general population.
Types of vWD:
Type 1: The most common form (75-85% of cases), characterised by a quantitative reduction in von Willebrand factor (VWF) levels.
Type 2: Caused by dysfunctional VWF with defects in specific protein functions.
Type 3: The rarest and most severe form, with little to no detectable VWF.
Transmission is generally autosomal dominant, except for some cases of Types 2N, 2A, and 2M, which can be autosomal recessive.
Common Manifestations:
Frequent bruising and mucocutaneous bleeding, which can occur at any age.
Women with vWD often experience heavy menstrual and postpartum bleeding.
Joint and soft tissue bleeding is uncommon in vWD but may appear in Types 2N and 3.
Some individuals have prolonged activated partial thromboplastin time (aPTT) due to low factor VIII levels.
Lab Testing:
Initial evaluation should include a CBC with platelet count and coagulation studies.
Screening tests for vWD, if required, should measure:
VWF protein levels (VWF antigen, VWF)
VWF functional activity (VWF activity, VWF)
Factor VIII activity level
A positive family history or a personal history of bleeding may prompt screening for VWD if VWF activity is <30%.
Hormonal Influence: VWF levels can increase with age, inflammation, and oestrogen, which may affect the presentation and diagnosis in certain populations.
