BLEEDING AND THROMBOTIC DISORDERS Flashcards

This deck covers bleeding and thrombotic disorders

1
Q

What’s your diagnosis?

Child

Abrupt onset of petechiae/ecchymoses around 1-2 weeks after viral illness

BT-Prolonged

Platelet count- low

PT- normal

PTT- normal

The bone marrow aspirate shows an increase in immature megakaryocytes

Deborah Dalmeida MD

A

Acute immune thrombocytopenic purpura (ITP)

Deborah Dalmeida MD

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2
Q

Vitamin K dependent coagulation factors

Deborah Dalmeida MD

A

II, VII, IX and X

Deborah Dalmeida MD

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3
Q
  1. Inherited thrombotic disorder caused by replacement of arginine by glutamine at position 506.
  2. Which coagulation factor levels are increased in this disorder as a result of the single base change?

Deborah Dalmeida MD

A
  1. Factor V Leiden
  2. Factor Va

Deborah Dalmeida MD

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4
Q

List the causes for DIC

Deborah Dalmeida MD

A

STOP Making Thrombi

  • Sepsis (gram negative)
  • Trauma
  • Obstetric complications
  • Pancreatitis
  • Malignancy
  • Transfusion

Deborah Dalmeida MD

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5
Q

List some antiphospholipid antibodies

Deborah Dalmeida MD

A

anticardiolipin antibodies

anti-β2-glycoprotein antibodies

lupus anticoagulants

Deborah Dalmeida MD

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6
Q
  1. Does heparin prolong PT or PTT ?
  2. How?

Deborah Dalmeida MD

A
  1. Prolongation of PT and PTT

Gotcha ;)

  1. Heparin activates ATIII- this in turn inhibits both sides of the coagulation cascade – VIIa, IXa, Xa, XIa and thrombin

Deborah Dalmeida MD

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7
Q

A 56 year old female with atrial fibrillation is started on a drug. 2 days later , she develops a lesion on her left lower limb as seen below. PT is prolonged.

1. What is the reason for the development of the lesion?

2. If this woman had an inherited Protein C deficiency, would she have a greater risk of developing this lesion?

Deborah Dalmeida MD

A
  1. Warfarin induced skin necrosis
  2. Protein C together with Factor VII has the shortest half life (6 and 14 hours respectively). In normal individuals, the fall in protein C activity following the start of warfarin is generally not of clinical significance, but in heterozygotes with levels of protein C that are about half of normal, a further drop in protein C activity during the first day of therapy can trigger thrombosis in the skin.

Deborah Dalmeida MD

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8
Q

Following platelet activation, Glycoprotein IIb/IIIa located on the surface of a platelet is able to cross link with another platelet via binding to which substance?

Deborah Dalmeida MD

A

Fibrinogen

Deborah Dalmeida MD

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9
Q

dyspnea, acute renal failure

BT-prolonged

Platelet count- Low

PT- Prolonged

PTT-Prolonged

Fibrinogen- decreased1.

1.Diagnosis?

2. Most sensitive screen?

Deborah Dalmeida MD

A
  1. DIC
  2. Elevated D-Dimers

Deborah Dalmeida MD

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10
Q

1. Diagnosis?

Neurologic symptoms
Fever
Kidney Failure

BT-Prolonged

Platelet count- Low

PT- Normal

PTT- Normal

2. Etiology?

Deborah Dalmeida MD

A
  1. Thrombotic Thrombocytopenic Purpura (TTP)
  2. Deficiency of ADAMTS13

Deborah Dalmeida MD

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11
Q

How does heparin cause life threatening thrombosis?

Deborah Dalmeida MD

A
  1. large complexes of IgG, PF4, and heparin detach from platelets, , attach to endothelial cells, and damage the endothelial cells, causing activation of the coagulation system
  2. Enhances AT III’s affinity for thrombin, IXa,Xa, XIa and XIIa

Deborah Dalmeida MD

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12
Q

glomerular capillaries occluded by microthrombi

renal failure

Schistocytes on a peripheral smear

BT- Prolonged

Platelet count- Low

PT- Normal

PTT- Normal

history of bloody diarrhea after eating an undercooked hamburger at a restaurant

Deborah Dalmeida MD

A

HUS

Deborah Dalmeida MD

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13
Q

2 properties of antiphospholipid antibodies

Deborah Dalmeida MD

A

a. Bind to phospholipid surface
b. bind to the phospholipid part of the PTT reagent

Deborah Dalmeida MD

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14
Q

Bernard Soulier/ vW disease?

BT- Prolonged

Platelet count-Low

PT- Normal

PTT- Normal

reduced ristocetin cofactor activity which does not normalize after the addition of normal plasma

Deborah Dalmeida MD

A

Bernard-Soulier syndrome

Deborah Dalmeida MD

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15
Q

superficial bleeding localized to skin and mucous membranes

Deborah Dalmeida MD

A

Purpura

Deborah Dalmeida MD

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16
Q

3 examples of malignancy associated with thromboses

Deborah Dalmeida MD

A

Trousseau Syndrome i.e migratory superficial thrombophlebitis

Thrombosis with chronic DIC

Nonbacterial thrombotic (marantic) endocarditis

Deborah Dalmeida MD

17
Q

Mechanism of heparin induced thrombocytopenia

Deborah Dalmeida MD

A

Drug + PF 4 = antigenic complex which reacts with antibodies–> immune complex–> bind to platelet Fc receptor –>platelet activation

Deborah Dalmeida MD

18
Q
  1. One test that you will perform to distinguish decreased production from increased destruction of a coagulation factor
  2. Explain the steps and interpretation of mixing studies.

Deborah Dalmeida MD

A
  1. Mixing studies

2.

Procedure: Normal plasma mixed with patient plasma

Interpretation:

a. Correction of the PT and/or PTT indicates decreased production of coagulation factors.
b. No correction of the PT and/or the PTT indicates immune destruction of coagulation factors is present. Antibody is also destroying the coagulation factor in the normal plasma that is added to the test tube.

Deborah Dalmeida MD

19
Q

easy bruising

recurrent joint bleeds

BT- Normal

Platelet count- Normal

PT- Normal

PTT- Prolonged

What are the chances of a female heterozygous carrier with a normal male partner, conceiving an affected son?

Deborah Dalmeida MD

A

50%

The diseases is Hemophilia A , X-linked recessive

Deborah Dalmeida MD

20
Q

Defect assoc with Bernard Soulier?

Deborah Dalmeida MD

A

inherited deficiency of the platelet membrane glyco­protein complex Ib-IX.

Deborah Dalmeida MD

21
Q

Consequence of a single base substitution in the 3′ untranslated region of the prothrombin gene

Deborah Dalmeida MD

A

30% higher plasma levels of structurally normal prothrombin

Deborah Dalmeida MD

22
Q

Young female

malar rash, renal failure

PS- Thrombocytopenia

PTT – Prolonged

Mixing study – does not correct the PTT

Kidney biopsy- Glomeruli show multiple capillary and arterial thromboses

Diagnosis?

Deborah Dalmeida MD

A

ANTIPHOSPHOLIPID ANTIBODY SYNDROME

Deborah Dalmeida MD

23
Q

2 to 5-mm mm, red or purple macules (spots); in the distal lower extremities ,conjunctiva and palate

Deborah Dalmeida MD

A

Petechiae

Deborah Dalmeida MD

24
Q

Can you recall 2 examples of “inhibitors”

Deborah Dalmeida MD

A

Factor VIII antibodies (most common)

antiphospholipid antibodies

Deborah Dalmeida MD

25
Q

Consequence of microthrombi formation in DIC

Deborah Dalmeida MD

A

tissue hypoxia and infarction

Deborah Dalmeida MD

26
Q

Give one word that describes this :

Circulating antibodies that destroy specific coagulation factors

Deborah Dalmeida MD

A

Inhibitors

Deborah Dalmeida MD

27
Q

Why do women with APLA have recurrent miscarriages?

Deborah Dalmeida MD

A

Due to antibody-mediated inhibition of t-PA activity necessary for trophoblastic invasion of the uterus

Deborah Dalmeida MD

28
Q

1. What’s your diagnosis?

Young adult, female

Insidious onset of petechiae, ecchymoses

BT- Prolonged

Platelet count- Low

PT - Normal

PTT- Normal

The bone marrow aspirate shows an increase in immature megakaryocytes

  1. What are the antibodies detected?

Deborah Dalmeida MD

A
  1. Chronic Immune Thrombocytopenic Purpura (ITP)
  2. autoantibodies directed against platelet membrane glycoproteins IIb-IIIa or Ib-IX

Deborah Dalmeida MD

29
Q

Why is PT/INR used to monitor patients on warfarin?

Deborah Dalmeida MD

A

Among all Vit K dependent coag factors Factor VII has the shortest half life.

So if you give a patient Coumadin, the first factor to show a decrease in activity will be factor VII (the others will drop off too, but not until later on).

it’s best to monitor therapy by taking a look at the extrinsic pathway (using the PT/INR), since that’s the pathway that will be affected first.

Deborah Dalmeida MD

30
Q

Defect assoc with Glanzmann thrombasthenia

Deborah Dalmeida MD

A

deficiency or dysfunction of glycoprotein IIb-IIIa

Deborah Dalmeida MD

31
Q

cause of hemorrhage in DIC

Deborah Dalmeida MD

A

depletion of factors required for hemostasis and the activation of fibrinolytic mechanisms

Deborah Dalmeida MD

32
Q

Primary versus secondary antiphospholipid syndrome

Deborah Dalmeida MD

A

Primary antiphospholipid syndrome :

  • manifestations of a hypercoagulable state
  • No evidence of other autoimmune disorders;
  • happens in association with certain drugs or infections.

Secondary antiphospholipid syndrome : seen in individuals with a well-defined autoimmune disease, such as systemic lupus erythematosus

Deborah Dalmeida MD

33
Q

Bernard Soulier/ vW disease?

BT- Prolonged

Platelet count-Normal

PT- Normal

PTT- Prolonged

reduced ristocetin cofactor activity which normalizes after the addition of normal plasma

Deborah Dalmeida MD

A

vW disease

Deborah Dalmeida MD

34
Q

Individual with known parenchymal liver disease

ecchymoses, easy bruisability

BT- Normal

Platelet count- Normal

PT- Prolonged

PTT- Prolonged

Fibrinogen - Normal

1. Diagnosis?

  1. Name the special poikilocyte seen on the peripheral smear. What history given above explains its appearance on the smear?

Deborah Dalmeida MD

A
  1. Vitamin K deficiency
  2. Acanthocyte- if due to severe liver disease

Deborah Dalmeida MD

35
Q

Very large, purpuric lesions

Deborah Dalmeida MD

A

Ecchymoses

Deborah Dalmeida MD

36
Q

Why do individuals with antiphospholipid antibodies exhibit prolonged PTT?

Deborah Dalmeida MD

A

The autoantibodies also just happen to bind to the phospholipid part of the PTT reagent . Then there’s not enough usable reagent in the test tube, and the patient’s specimen doesn’t clot! The coagulation tests are therefore falsely prolonged.

Deborah Dalmeida MD