[W7] Bleeding disorders

Question 1

What are primary haemostatic disorders?

Answer 1

Disorders affecting platelets (number/function).

Question 2

What is a secondary haemostatic disorder?

Answer 2

Disorders affecting the coagulation cascade.

Question 3

What is thrombocytopenia?

Answer 3

Platelet count <150×10⁹/L.

Question 4

Name immune and non-immune causes of thrombocytopenia.

Answer 4

• Immune: ITP
• Non-immune: TTP, DIC

Question 5

What antibody is found in ITP?

Answer 5

Anti-αIIbβ3.

Question 6

What is first-line treatment for chronic ITP?

Answer 6

• Corticosteroids
• IVIG
• Splenectomy

Question 7

What enzyme is deficient in TTP?

Answer 7

ADAMTS13.

Question 8

What is the classic blood film finding in TTP?

Answer 8

Schistocytes (fragmented RBCs).

Question 9

What lab features indicate DIC?

Answer 9

• ↓ platelets
• ↑ D-dimer
• Prolonged PT/aPTT

Question 10

Name 2 DIC triggers.

Answer 10

• Sepsis
• Malignancy

Question 11

What is the most common inherited platelet disorder?

Answer 11

von Willebrand Disease (VWD).

Question 12

What test is abnormal in VWD?

Answer 12

Platelet aggregation to ristocetin.

Question 13

What causes Glanzmann’s thrombasthenia?

Answer 13

GPIIb/IIIa defect → no fibrinogen binding.

Question 14

How does aspirin affect platelets?

Answer 14

Irreversibly inhibits cyclooxygenase (COX-1).

Question 15

Why does renal failure cause bleeding?

Answer 15

Uraemia impairs platelet-vessel wall interaction.

Question 16

What factor is deficient in Haemophilia A?

Answer 16

Factor VIII.

Question 17

How is Haemophilia A inherited?

Answer 17

X-linked recessive.

Question 18

What is the treatment for mild Haemophilia A?

Answer 18

• DDAVP
• FVIII concentrate

Question 19

What disorder is common in Ashkenazi Jews?

Answer 19

Factor XI deficiency.

Question 20

What vitamin is essential for coagulation?

Answer 20

Vitamin K.

Question 21

What drug inhibits Vitamin K recycling?

Answer 21

Warfarin.

Question 22

What causes acquired haemophilia?

Answer 22

Autoantibody against FVIII.

Question 24

↓ Platelets + Normal PT/aPTT + large platelets = ?

Answer 24

ITP (Immune thrombocytopenia)

Immune thrombocytopenia is a condition characterized by a low platelet count due to immune-mediated destruction.

Question 25

↓ Platelets + Schistocytes + Normal PT/aPTT = ?

Answer 25

TTP (Thrombotic thrombocytopenic purpura) ## Footnote TTP is a rare blood disorder characterized by the formation of microthrombi, leading to low platelet counts and schistocytes.

Question 26

↓ Platelets + ↑ PT/aPTT + D-dimer = ?

Answer 26

DIC (Disseminated intravascular coagulation) ## Footnote DIC is a serious condition that involves the widespread activation of the clotting cascade, leading to the formation of blood clots and subsequent bleeding.

Question 27

↑ aPTT only = ?

Answer 27

Haemophilia A or B, or VWD ## Footnote The increase in activated partial thromboplastin time (aPTT) suggests a problem with the intrinsic pathway of coagulation, associated with these bleeding disorders.