Abnormalities of Haemostasis

Question 1

What is the fibrinolytic pathway?

Answer 1

Removes the clot after the vasculature is repaired
ALSO degrades clots that form in the bloodstream.

Plasminogen is converted to plasmin by tissue plasminogen activator (tPA) which breaks down fibrin-based clots.

Question 2

What basic laboratory test are used to investigate the haemostatic system?

Answer 2

1) Platelet Count
2) Prothrombin Time
3) Activated Partial Thromboplastin Time
4) Fibrinogen level

Question 3

What is von Willebrand disease?

Answer 3

Quantitative deficiency of von Willebrand factor
(blood glycoprotein involved in hemostasis).

Type 1 –> Partial
Type 2 –> Different variations (A, B, M, N)
Type 3 –> Virtually complete

Question 4

What is Thrombotic Thrombocytopenic Purpura (TTP)?

Answer 4

A rare blood disorder leading to clot formation in small blood vessels.

Based on ADAMTS13 gene –> Severe deficiency of ADAMTS13 means vwf is not cleaved leading to accumulation of platelets.

Can be inherited or acquired.

Question 5

What is haemophilia?

Answer 5

Inherited bleeding disorder where the blood does not clot effectively.

Autosomal recessive x-linked gene –> Females are typically carriers and males mainly get the disease.

Haemophilia A –> Not enough clotting factor VIII
Haemophilia B –> Not enough clotting factor IX
Haemophilia C –> Not enough clotting factor XI
Parahaemophilia –> Not enough clotting factor V