Bleeding Disorders

Question 1

Normal hemostasis requires a balance between what 3 elements?

Answer 1

Platelets, coagulation factors, and endothelial cells

Question 2

Senile purpura, purpura simplex, and scurvy are all hemostatic dysfunctions that occur in what compartment of the body?

Answer 2

Extravascular compartment

Question 3

What event causes the vessel wall weakness and purpura of amyloidosis, cyroglobulinemia, other paraproteinemias, and arteritis?

Answer 3

Immunoglobulin fragment deposition

Question 4

What platelet disease, also known as Rendu-Osler-Weber Syndrome, is characterized by dilation and thinning of venule and capillary walls, arteriovenous malformations of multiple solid organs, and telangiectasias of the mucous membranes and dermis?

Answer 4

Hereditary hemorrhagic telangiectasia

Question 5

What platelet disease, also known as allergic purpura, is characterized by IgA and complement mediated vascular damage, platelet plugs, and leukocytoclastic vasculitis?

Answer 5

Henoch Schonlein purpura

Question 6

How does the presentation of Henoch Schonlein purpura differ between kids and adults?

Answer 6

In kids: follows viral infections, self-limited

In adults: often from drug exposure, chronic

Question 7

What term describes an inflammation of blood vessels that destroys WBCs?

Answer 7

Leukocytoclastic vasculitis

Question 8

The congenital thrombocytopenias or MYH9-related platelets disorders (May-Hegglin anomaly, Epstein syndrome, Fechtner syndrome and Sebastian platelet syndrome) are due to what cause of thrombocytopenia?

Answer 8

Decreased platelet production

Question 9

What kind of thrombocytopenia is an autoimmune disease due to antibodies directed against platelet or megakaryocyte antigens?

Answer 9

ITP (idiopathic thrombocytopenic purpura)

Question 10

HIT (heparin-induced thrombocytopenia) type I and II belong to what category of thrombocytopenia? Which type is immune mediated, and which type is more dangerous?

Answer 10

Drug-induced thrombocytopenia; type II is autoimmune and more dangerous

Question 11

Which type of HIT involves IgG antibodies against platelet factor 4–heparin complexes, leading to a hypercoagulable state?

Answer 11

HIT type II

Question 12

List 2 conditions that can follow the increased platelet destruction of pregnancy-associated thrombocytopenia.

Answer 12

Preeclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelets)

Question 13

GIve 3 kinds of neonatal thrombocytopenias associated with increased platelet destruction.

Answer 13

X-linked (ex. Wiskott-Aldrich syndrome), Fanconi anemia, NAIT (neonatal alloimmune thrombocytopenia)

Question 14

Posttransfusion purpura involves platelet destruction because of antibodies against what platelet antigen?

Answer 14

HPA-1

Question 15

List the 5 features that unite the thrombotic microangiopathies.

Answer 15

Thrombocytopenia, microangiopathic hemolytic anemia, neurologic symptoms, fever, and renal impairment

Question 16

The pathology of what 2 disorders result from widespread platelet aggregation and hyaline thrombi deposition in the microcirculation?

Answer 16

TTP (thrombotic thrombocytopenic purpura) and HUS (hemolytic uremic syndrome) - the thrombotic microangiopathies

Question 17

The pathogenesis of TTP is believed to involve a deficiency in what metalloprotease that normally cleaves von Willebrand factor?

Answer 17

ADAMTS13

Question 18

What hemostatic disorder of platelets features PAS (periodic acid-Schiff) positive microthrombi and no inflammation in the microvasculature?

Answer 18

TTP (thrombotic thrombocytopenic purpura)

Question 19

While TTP can be seen in all ages and has a variety of causes, HUS is generally seen in what age group and caused by what 2 infectious diseases?

Answer 19

Children; follows E. coli or Shigella infection

Question 20

Comparing TTP vs. HUS: In which one is platelet aggregation due to lack of ADAMTS13 metalloprotease and large vWF multimers, and in which one is it due to endothelium damage?

Answer 20

TTP; HUS

Question 21

Contrast the 4 causes of reactive thrombocytosis and the 1 main cause of clonal thrombocytosis.

Answer 21

Reactive can be due to iron-deficiency anemia, splenectomy, cancer, or chronic inflammation.
Clonal is due to myeloproliferative neoplasms.

Question 22

What coagulation factors are mutated in hemophilia A and B?

Answer 22

VIII; IX

Question 23

Which coagulopathy is the most common X-linked inherited bleeding disorder, seen in every 5,000-10,000 males?

Answer 23

Hemophilia A

Question 24

Of the 3 types of von Willebrand disease, which involves qualitative defects, which involves quantitiative defects, and which involves complete absence of vWF?

Answer 24

Type I is quantitative deficiency (all multimers decreased)
Type II is qualitative deficiency (IIa, missing high MW multimers; IIb, increased platelet affinity)
Type III is no vWF activity (and often low factor VIII, too)

Question 25

Which type of von WIllebrand disease is the rarest and most severe?

Answer 25

Type III (complete absence of vWF activity and only 10% of normal factor VIII)

Question 26

Liver disease or malabsorption due to antibiotics can lead to a deficiency in what vitamin, which is needed to make factors II, V, VII, IX, and X and to carboxylate their Glu residues? Which factor does not need carboxylation in order to be active?

Answer 26

Vitamin K; factor V

Question 27

List 3 stages in disseminated intravascular coagulation.

Answer 27

1. Uncontrolled thrombin generation forms fibrin clots in the microvasculature
2. Fibrinolysis consumes platelets and coagulation factors
3. Hemorrhagic diathesis (tendency to bleed) results

Question 28

What molecule is the main trigger of DIC because it initiates thrombin formation/activation?

Answer 28

Tissue factor

Question 29

How does microangiopathic hemolytic anemia occur in DIC?

Answer 29

Webs of intravascular fibrin degrade RBCs

Question 30

What is the most common genetic disorder associated with hypercoagulability? What enzyme does the body become resistant to?

Answer 30

Factor V Leiden mutation; Activated protein C resistance

Question 31

What hypercoagulability disorder features thrombosis of arteries and veins, spontaneous abortions, and IgG mediated thrombocytopenia and anemia?

Answer 31

Antiphospholipid antibody syndrome

Question 32

Describe the effect of lupus anticoagulant antiphospholipid antibodies on blood clotting in vitro and in vivo.

Answer 32

In vitro - prolongs PTT, but in vivo - causes hypercoagulation