Bleeding Disorders

Question 1

What is a bleeding disorder?

Answer 1

A bleeding disorder refers to an issue with the blood clotting process, leading to abnormally heavy and prolonged bleeding. It can sometimes occur spontaneously.

Question 2

What are the causes of abnormal bleeding?

Answer 2

Blood vessel/vascular disorders, platelet disorders, or coagulation pathway disorders can cause abnormal bleeding.

Question 3

What are some examples of inherited blood vessel/vascular disorders?

Answer 3

Two examples of inherited blood vessel/vascular disorders are hereditary haemorrhagic telangiectasia and collagen abnormalities.

Question 4

What are the characteristics of hereditary haemorrhagic telangiectasia?

Answer 4

• It is an uncommon disorder.

It is inherited in an autosomal dominant manner.
It is characterized by dilated microvascular swellings in various parts of the body, including the skin (hands and fingertips), mucous membranes, and internal organs.
Symptoms may include nose bleeds and gastrointestinal bleeds.

Question 5

What are the features of collagen abnormalities?

Answer 5

• Collagen abnormalities result in the fragility of the skin, ligaments, blood vessels, and perivascular connective tissue.

Individuals with collagen abnormalities may experience easy bleeding and bruising.

Question 6

What are some acquired causes of bleeding disorders related to blood vessel/vascular disorders?

Answer 6

Acquired causes include scurvy (vitamin C deficiency), which can lead to bleeding gums, peri-follicular hemorrhages, and bruises. Other causes are steroid Rx (associated with Cushing’s syndrome) and old age.

Question 7

What are the characteristics of hereditary haemorrhagic telangiectasia?

Answer 7

• It is an uncommon disorder.

It is inherited in an autosomal dominant manner.
It is characterized by dilated microvascular swellings in various parts of the body, including the skin (hands and fingertips), mucous membranes, and internal organs.
Symptoms may include nose bleeds and gastrointestinal bleeds.

Question 8

What are some platelet disorders related to abnormalities in platelet numbers?

Answer 8

Platelet disorders related to abnormalities in platelet numbers include thrombocytopenia (platelet count < 150 x 109/L). Symptoms of low platelet counts may include epistaxis (nosebleeds), gastrointestinal bleeds, menorrhagia (excessive menstrual bleeding), bruising, and petechiae/purpura.

Question 9

Are inherited causes of platelet disorders common?

Answer 9

No, inherited causes of platelet disorders are rare. However, when present, they are often associated with other congenital abnormalities, and many individuals show both numerical and functional platelet abnormalities.

Question 10

Are acquired causes of platelet disorders common?

Answer 10

Yes, acquired causes of platelet disorders are common. These causes can vary and may include various medical conditions or factors.

Question 11

What is Immune thrombocytopenic purpura (ITP)?

Answer 11

ITP is an autoimmune condition characterized by acute or chronic low platelet counts. In children, it is often acute and follows an infection, resolving on its own. In adults, it can be acute or chronic with various triggers, and the patient’s medical history is important to identify potential causes.

Question 12

What are some key features of ITP?

Answer 12

ITP can affect both men and women equally. It involves the production of auto-antibodies against platelets, leading to their removal by the spleen. Treatment may be necessary if there is bleeding or if platelet counts drop below 30. Treatment options include steroids, IV immunoglobulins, TPO agonists, monoclonal antibodies, and occasionally splenectomy.

Question 13

What are some inherited platelet function disorders?

Answer 13

Mutations in membrane glycoproteins or defects in platelet storage organelles or granules can cause inherited platelet function disorders.

Question 14

What are some acquired platelet function disorders?

Answer 14

Certain drugs, such as aspirin, clopidogrel, and NSAIDs can cause acquired platelet function disorders. Herbal remedies and acquired von Willebrand’s syndrome can also contribute to platelet function abnormalities.

Question 15

What is haemophilia?

Answer 15

Haemophilia is a bleeding disorder that affects the body’s ability to control blood clotting, which is necessary to stop bleeding. It is often a serious condition.

Question 16

What are the types of haemophilia based on the affected clotting factor?

Answer 16

Haemophilia A is caused by factor VIII deficiency, while haemophilia B, also known as Christmas disease, is caused by factor IX deficiency.

Question 17

What are the clinical features of haemophilia?

Answer 17

Clinical features of haemophilia include spontaneous bleeding into joints and muscles, chronic debilitating joint disease, and unexpected post-operative bleeding. Most cases have a family history, although around one-third of cases are due to spontaneous mutations. Haemophilia is carried on the X chromosome.

Question 18

What are some tests used for coagulation disorders?

Answer 18

Tests for coagulation disorders include APTT (activated partial thromboplastin time), which tests the intrinsic pathway, and PT (prothrombin time), which tests the extrinsic pathway. Other tests include INR (international normalized ratio), TT (thrombin time), fibrinogen level, factor level assay, and bleeding time.

Question 19

What are the typical blood test results in haemophilia A and B?

Answer 19

In haemophilia A and B, the APTT is prolonged, indicating impairment in factors VII, IX, XI, and XII of the intrinsic pathway. The PT is normal, indicating normal function of factors II, VII, and X in the extrinsic pathway. Haemophilia A shows low factor VIII levels, while haemophilia B shows low factor IX levels. The severity is determined by the percentage of factor levels, with less than 1% being classified as severe, 1-5% as moderate, and greater than 5% as mild.

Question 20

What are the treatment options for haemophilia?

Answer 20

The treatment of haemophilia involves the use of recombinant DNA to produce products. Infusions of recombinant factor VIII or factor IX are administered to replace the deficient clotting factors. Treatment can be prophylactic, aiming for a level of 50-100% of normal, and administered every 2-3 days. Prophylactic treatment has significantly improved the management of haemophilia patients. On-demand treatment is used only when bleeding occurs or when there is a need to prevent bleeding, such as during surgery.

Question 21

What is von Willebrand’s factor (vWF)?

Answer 21

Von Willebrand’s factor is a large multimeric glycoprotein synthesized by endothelial cells and megakaryocytes. It acts as a bridging molecule between platelets and collagen at sites of vascular injury, promoting platelet aggregation. Von Willebrand’s disease (vWD) is characterized by a deficiency of vWF and Factor VIII in the plasma. It is the most common inherited clotting abnormality, with several subtypes involving quantitative and qualitative issues with vWF.

Question 22

What are some common symptoms of von Willebrand’s disease?

Answer 22

Von Willebrand’s disease can lead to mucocutaneous bleeds, nosebleeds, and menorrhagia (excessive menstrual bleeding) due to the deficiency or quality problem of von Willebrand factor.

Question 23

What are the typical blood test results in von Willebrand’s disease (vWD)?

Answer 23

In vWD, the APTT is either normal or prolonged, the PT is normal, and there is a low vWF level. There may also be vWF function abnormalities and low factor VIII level. Platelet numbers are typically normal or low, and there may be defective platelet function. The bleeding time is often prolonged.

Question 24

What are the treatment options for von Willebrand’s disease (vWD)?

Answer 24

Treatment of vWD may include the use of desmopressin (DDAVP), which increases the synthesis and release of vWF. Anti-fibrinolytics, such as tranexamic acid, can be used to reduce thrombus breakdown. In more severe cases, plasma products containing vWF and Factor VIII may be administered to replace the deficient components.

Question 25

What is acquired haemophilia?

Answer 25

Acquired haemophilia is a rare condition characterized by the presence of auto-antibodies (inhibitors) to clotting factors, effectively rendering the affected clotting factor deficient. Acquired Haemophilia A is the most common form. It is important to identify the underlying driver that has led to antibody formation, which can include malignancy, autoimmune disorders, viral infections, or pregnancy. Treatment of acquired haemophilia is complex and may involve the use of bypassing agents and immunosuppression.

Question 26

How does liver disease affect coagulation?

Answer 26

Liver disease can lead to defects in the synthesis of clotting proteins, resulting in a deficiency of these proteins. It can also cause a degree of “auto-anticoagulation,” meaning a decreased ability to form blood clots. Bleeding disorders and thrombotic disorders can both occur in liver disease. Additionally, liver disease can impair platelet number and function, further affecting coagulation.

Question 27

What are the factors dependent on vitamin K?

Answer 27

The vitamin K-dependent factors include Factors X, IX, VII, and II (also known as proteins S and C). These factors are required for gamma carboxylation. A mnemonic to remember them is “1972 was the diSCo era.”

Question 28

What can cause vitamin K deficiency?

Answer 28

Vitamin K deficiency can occur due to fat malabsorption, biliary obstruction (jaundice), or in the newborn state, leading to haemorrhagic disease of the newborn. Warfarin acts as a vitamin K antagonist, interfering with the function of vitamin K-dependent factors.

Question 29

What is disseminated intravascular coagulation (DIC)?

Answer 29

DIC is a condition characterized by the breakdown of the balance between coagulation and fibrinolysis. It can occur in various situations, such as septicemia (e.g., meningococcal infection), acute promyelocytic leukemia, cancer, trauma, and pregnancy complications. It involves the widespread activation of coagulation, leading to the consumption of clotting factors and platelets.

Question 30

What are the typical blood test results in DIC?

Answer 30

In DIC, there is a prolonged PT (prothrombin time) and APTT (activated partial thromboplastin time), low fibrinogen levels, low platelet counts, and elevated D-dimer and fibrin degradation products (FDPs). Additionally, red cell fragments may be observed on a blood film.

Question 31

How is DIC treated?

Answer 31

Treatment of DIC involves addressing the underlying cause, such as administering antibiotics for sepsis. Supportive treatment with blood products may be necessary to correct coagulation abnormalities if bleeding is present. Vitamin K may also be given.