Coagulation disorders

Question 1

What are coagulation disorders?

Answer 1

Disorders that stop the ability of blood to coagulate

They can be hereditary or acquired.

Question 2

List the types of coagulation disorders.

Answer 2

• Hereditary
• Acquired

Examples include hemophilias and von Willebrand disease for hereditary, and vitamin K deficiency for acquired.

Question 3

What is hemophilia A?

Answer 3

Genetic factor VIII deficiency, X-linked recessive

Predominantly affects males due to one X chromosome.

Question 4

What is the clinical significance of the severity of hemophilia A?

Answer 4

Depends on the degree of deficiency

More severe deficiencies lead to more significant bleeding.

Question 5

What are the laboratory findings for hemophilia A?

Answer 5

• Elevated PTT
• Normal PT
• Decreased factor VIII
• Normal platelet count and bleeding time

PTT examines the intrinsic pathway while PT examines the extrinsic pathway.

Question 6

What is the treatment for hemophilia A?

Answer 6

Recombinant FVIII

This helps to replace the deficient factor VIII.

Question 7

What is von Willebrand disease?

Answer 7

Deficiency of von Willebrand factor, synthesized by endothelium

It is the most common inherited coagulation disorder.

Question 8

What are the main functions of von Willebrand factor?

Answer 8

• Stability of factor VIII
• Role in platelet adhesion to vessel wall

Its deficiency leads to faster breakdown of factor VIII.

Question 9

What are the laboratory findings for von Willebrand disease?

Answer 9

• Decreased factor VIII
• Prolonged bleeding time
• Normal PT
• Abnormal Ristocetin test

The Ristocetin test assesses platelet aggregation.

Question 10

What is the treatment for von Willebrand disease?

Answer 10

Desmopressin (ADH analog)

It increases vWF release from endothelial cells.

Question 11

What is hemophilia B?

Answer 11

Genetic factor IX deficiency

It is also X-linked.

Question 12

List common symptoms of hemophilia A and B.

Answer 12

• Ecchymosis
• Easy bruising
• Hematomas
• Prolonged bleeding
• Gastrointestinal bleeding
• Hematuria
• Epistaxis
• Hemarthrosis

These symptoms are due to deficiencies in clotting factors.

Question 13

What is hemophilia C?

Answer 13

Factor XI deficiency

It is less common than hemophilia A and B.

Question 14

What is Factor V Leiden?

Answer 14

Mutated form of human factor V causing hypercoagulability

It lacks the cleavage site for deactivation by proteins C and S.

Question 15

What is the pathogenesis of Factor V Leiden?

Answer 15

Mutated factor V lacks the cleavage site for protein C, leading to no limitation on clotting

This results in abnormal recurrent venous thrombosis.