Heritable bleeding disorders Flashcards Preview

Clinical Pathology > Heritable bleeding disorders > Flashcards

Flashcards in Heritable bleeding disorders Deck (43):
1

What is the process by which platelets AGGREGATE to the injury site?

-Damage to vascular wall
-Platelets adhere to point of injury
-Sticks to vWf (activates platelets) and then collagen
- Platelet plugs holes
- Require fibrin formation to stabilise clot

2

What intracellular processes are involved in the positive activation of more platelets?

Thromboxin release - constricts blood vessels and activates platelets

Alpha granules - coagulation factors, adhesion proteins, firbonolytics factors etc

3

What is the platelet receptor for fibrinogen?

Glycoprotein 2B3A

4

What is the platelet receptor for vWf?

Glycoprotein 1B9

5

How does aspirin mediate its function?

COX inhibitor - enzyme which synthesis thromboxin in platelet

6

What are the action of 2B3A antagonists?

Prevent platelet fibrinogen adhesion

7

What factors are activated by thrombin?

V, VIII, XI, XIII

8

What comprises the extrinsic coagulation cascade?

TF, VII

9

What comprises the extrinsic coagulation cascade?

TF, VII, X (along with factor V)

10

What comprises the intrinsic tissue cascade?

XII, XI, IX, VIII

11

What comprises the common pathway of the coagulation cascade?

X, V and prothrombin

12

What is the pathway that prothrombin time is timing?

Extrinsic/common pathway

TF substitute (fibroplatin) see how long it takes for fibrin to form)

13

What is the activated partial thromboplastin time counting?

Intrinsic pathway

foreign regents added e.g. silica based - activated factor 12

14

If prothrombin time is high, where do the deficiencies i.e.?

Factors in the extrinsic and common pathway

15

During activated partial thromboplastin timing, what is added to the mixture and why?

Calcium and phospholipids

Platelet substitute and some factors are calcium dependent

16

What effects the activated partial thromboplastin time?

Abnormalities in the INTRINSIC or common pathway

17

What 3 investigations that comprise a coagulation screen?

-Prothrombin time
-Activated partial thromboplastin time
-Thrombin clotting Time

18

What is the thrombin clotting time timing?

Time from thrombin added to plasma to formation of fibrin clot

19

What factors are involved in anticoagulation?

Protein C/S
Anti-thrombin III
Fibrinolytic system

20

What does the fibrinolytic system comprise?

Activation of plasminogen to plasmin (T-PA; tissue plasmin activation factor)

Breakdown of fibrin to fibrinogen degradation products (by plasmin)

21

How is this fibrinolytic system taken advantage of with an MI?

Use of T-PA to break down clot!

22

How are bleeding disorders characterised?

-Acquired
-Congenital
-Coagulation disorgers
-Aggregation/adhesion disorders

23

What sort of bleeding patters would you observe for secondary bleeding/coagulation defects?

Deep muscular and joint bleeds (haemarthitris)

Deep spreading haematomas

Retroperitoneal bleeding

Prolonged, recurrentbleeding

24

What sort of patterns of bleeding would you observe with primary bleeding/platelet aggregation disorders? e.g. vWf

-Mucocutaneous bleeding inc heavy periods

Petechiae/superficial bleeds

- Nose bleeds

- Immediate, prolonged bleeds, non-recurrent

25

What are the main types of defects you observe with platelet/vessel wall defects?

Reduced platelet number

Abnormal platelet function - e.g. production of thromboxane, dysfunctional receptors

Abnormal vessel wall e.g. collagen and survey

Abnormal interaction between platelet and vessel wall e.g. vW disease

26

What do all platelet/vessel or coagulation defects all end up causing?

Prolonged bleeding

27

What are the three types of vW disease?

Type I - some proteins absent but maintains multimeric structure - mild bleeding

Type 2 - right number of proteins but abnormal multimeric structure - mild bleeding

Type 3 - no vWf at all - severe bleeding

28

What are the vW disease types inheritance patterns?

Type1/2 - autosomal dominant

Type 3 - autosomal recessive

29

What is the other function for vWf?

Carrier protein for factor VIII

Therefore, reduced VIII level

Defects of coagulative disorders may present e.g. deep bleeding/haemoarthiritis

30

For vWd are male or females more effected?

F=M (autosomal dominant inheritance)

31

What is the treatment for vW disease/

Antifibrinolytics - tranexamic acid

Factor concentrates containing vWf

Blood donation with vWf

32

What factor is associated with haemophilia A?

Factor 8

33

What factor is associated with haemophilia B?

Factor 9

34

What is the inheritance pattern for haemophilia A/B

Sex linked recessive

35

What factor is von villibrand factor associated with?

Factor 8 - transport protein

36

What is the inheritance patterns for factors I, II, V, VII, X, XIII

Autosomal recessive

37

What is the inheritance pattern for factors XII and XI?

Autosomal dominant

38

What are the chances of a son/daughter being a carrier/suffer for Haemophilia A/B if mother is carrier?

50% for son to be suffers, females being carrier

39

What are the chances of the sons being suffers and daughters being carriers if father has haemophilia A/B

All Daughters will be carriers

No sons will be suffers

40

What is the degree of haemophilia dependent on?

Family severity - sons will not be more/less effected - the same

41

What are the degrees of severity of haemophilia?

Normal 50-150%
Mild 6- 50%
Moderate 1 -5%
Severe

42

What are the types of bleeds you get with haemophilia? What are the types of bleeds dependent on?

- Spontaneous
-Traumatic bleeds

Severity of haemophilia - i.e. more severe, easily bleeding!

Haemoarthiritis
Muscle bleeds
Soft tissue bleeds
Life threatening e.g. cranial/airway

43

What are the treatment options for haemophilia A/B

Replacement of clotting factors

Antifibrinolytics e.g. tranexamic acid

Decks in Clinical Pathology Class (50):