Abnormal Hemostasis

Question 1

What is APTT?

Answer 1

Activated partial thromboplastin time (APTT) is a medical test that characterizes blood coagulation. It is an indicator of the Intrinsic Pathway.

Question 2

What is PT/INR?

Answer 2

Prothrombin time (PT) and international normalized ratio (INR) are assays that evaluate the Extrinsic Pathway.

Question 3

Thrombocytosis

Answer 3

Increased platelet count

Question 4

Thrombocytopenia

Answer 4

Decreased platelet count

Question 5

Primary fibrinolysis

Answer 5

In primary fibrinolysis, fibrinogen is converted into fibrinogen degradation products.

Question 6

Secondary fibrinolysis

Answer 6

In secondary fibrinolysis both fibrin and fibrinogen are digested by plasmin.

Question 7

What are the categories of quantitative platelet disorders?

Answer 7

Thrombocytopenia

Thrombocytosis

Question 8

What are some of the common causes of thrombocytopenia?

Answer 8

• Bone marrow hypoplasia
• Hereditary thrombocytopenia
• Drug induced thrombocytopenia

Question 9

Immune thrombocytopenic purpura (ITP)

Answer 9

Presentation with purpura on the skin and increased bleeding due to IgG mediated autoimmunity resulting in low platelets

Question 10

Thrombotic thrombocytopenic purpura (TTP)

Answer 10

Cause formation of microscopic thrombi that can damage organs due to the inhibition of ADAMTS13 which results in multimers of vWF to increase in the blood and increase the amount of platelets in adhesion.

Question 11

How does aspirin alter platelets?

Answer 11

It blocks the formation of thromboxane A2 as it is a COX inhibitor which leads to the inhibition of platelet aggregation

Question 12

Glanzmann’s Thrombasthenia

Answer 12

Defect in GP IIb and IIIa that interferes with platelet aggregation and increases the bleeding time

Question 13

Bernard-Soulier Disease

Answer 13

Defect in GP Ib prevents platelet adhesion which will increase the bleeding time

Question 14

Storage Pool Disease

Answer 14

Decrease in the number of dense granules so aggregation is interfered with and bleeding is prolonged.

Question 15

What are some causes of thrombocytosis?

Answer 15

• Splenectomy
• Reaction to cancer/drugs/infection
• Autonomous increase in platelets (thrombocythemia)

Question 16

What are qualitative platelet disorders?

Answer 16

Platelet numbers are usually normal, however, platelet function is impaired.

Question 17

What are some causes of qualitative platelet disorders?

Answer 17

• Disease induced platelet defects
• Drug induced platelet defects
• Diet induced platelet defects

Question 18

What is the cause and manifestation of Gray Platelet Syndrome?

Answer 18

Lack of alpha granules. Present with purpura of unknown origin.

Question 19

How does Omega-3 affect platelet function?

Answer 19

Blocks generation of thromboxane A2

Question 20

Polycythemia Vera

Answer 20

Cancer of the red cell and there is a high production in the amount of RBCs

Question 21

What are the 3 categories of vascular disorders that lead to bleeding?

Answer 21

• Subendothelial
• Endothelial
• Mechanical

Question 22

What is an example of a congenital sub endothelial disorder?

Answer 22

Ehler Danlos Syndrome

Question 23

What are some symptoms of Ehler Danlos Syndrome?

Answer 23

Hypermobile joints. Hyperflexible skin, osteogenesis imperfecta, drugs, infections, amyloidosis.

Question 24

Telangiectasias

Answer 24

Small dilated blood vessels near surface of skin

Question 25

What are examples of congenital endothelial disorders?

Answer 25

Telangiectasia (HHT) Arteriovenous malformation Giant hemangioma (Kasaback- Merritt syndrome)

Question 26

What is a nutritional disorder that can affect bleeding?

Answer 26

Scurvy

Question 27

What are examples of bleeding disorders due to coagulation factor abnormalities?

Answer 27

Hemophilias | von Willebrand's Disease

Question 28

Hemophilia A

Answer 28

VIII coagulation factor deficiency

Question 29

Hemophilia B

Answer 29

IX coagulation factor deficiency

Question 30

What pathway does Hemophilia A and B affect?

Answer 30

Intrinsic

Question 31

What is the effect of hemophilia on APTT?

Answer 31

It is elevated

Question 32

What is the effect of hemophilia on platelet function?

Answer 32

Normal Platelet Function

Question 33

What is the effect of hemophilia on bleeding time?

Answer 33

Normal bleeding time

Question 34

von Willebrand's Disease with Types 1, 2 and 3

Answer 34

1. Type-1 and Type-3 von Willebrand’s diseases are characterized by a decrease in the circulating level of the factor. 2. Type-2 von Willebrand’s disease is characterized by a qualitative defect in the protein.

Question 35

What is the effect of vW's disease on APTT?

Answer 35

Slightly elevated

Question 36

What is the effect of vW's disease on platelet function?

Answer 36

Impaired platelet adhesion

Question 37

What is the effect of vW's disease on bleeding time?

Answer 37

Increased bleeding time

Question 38

What can excessive activation of the fibrinolytic system cause?

Answer 38

Bleeding

Question 39

What is the D-dimer test used for?

Answer 39

It tests for fibrin degradation products and is used to assess DIC/DVT states.

Question 40

What can lead to Disseminated Intravascular Coagulation (DIC)?

Answer 40

Sepsis Tissue Destruction Endothelial Injury

Question 41

What is DIC?

Answer 41

Disseminated Intravascular Coagulation. Occurs when both fibrinogen and fibrin are degraded by plasmin which consumes clotting factors and platelets leading to bleeding.

Question 42

What can α2-antiplasmin deficiency cause?

Answer 42

Increased fibrinolysis and bleeding

Question 43

Heparin Induced Thrombocytopenia

Answer 43

Platelet Factor 4 complexes with heparin and causes and antibody response which leads to HIT as platelets are targeted by antibodies

Question 44

What is bleeding in HIV mainly associated with?

Answer 44

Thrombocytopenia

Question 45

Which of the blood clotting tests is commonly used for the diagnosis of Hemophilias? A. Activated partial thromboplastin time B. Prothrombintime/INR C. Thrombin time D. Bleeding time E. Fibrinogenlevels

Answer 45

A. Activated partial thromboplastin time

Question 46

``` A patient was admitted to the hospital with an urinary tract infection. Two days later he developed fever and his coagulation parameters and platelet count became abnormal. Additional test showed D-dimer positive and positive blood cultures for E. Coli. What is the likely diagnosis of this patient? A. DIC B. Hemophilia B C. Hypercoagulable state D. APC Resistance E. Von Willebrand disease ```

Answer 46

A. DIC

Question 47

Factor V Leiden

Answer 47

Abnormal V is cleaved to Va and it is resistant to Protein C cleavage which leads to thrombophilia leading to increased clotting

Question 48

Prothrombin 20210A

Answer 48

Elevated plasma prothrombin levels leads to an increase in venous thrombosis.

Question 49

Hyperhomocysteinemia

Answer 49

Methylene tetrahydrofolate reductase mutation (mtHfr C677t) results in a moderate increase in serum homocysteine, which is associated with both arterial and venous thrombosis.