Disorders of Primary Hemostasis

Question 1

Vascular Disorder

Answer 1

Manifests with superficial bleeding
Lab tests are normal
Diagnosis requires histological evaluation of blood vessel/genetic tests
Suspected after other major causes of bleeding are ruled out

Question 2

Acquired Vascular Disorders

Answer 2

Loss of connective tissue
Dysproteinemia
Vascular inflammation
Mechanical purpura
Easy bruising syndrome

Question 3

Loss of Connective Tissue

Answer 3

Senile purpura: loss associated with age
Cushing syndrome: excess glucocorticoids breakdown collagen
Vitamin C deficiency (scurvy): vitamin C is needed to make collagen

Question 4

Dysproteinemia

Answer 4

Cryoproteins that precipitate in the circulation (cold agglutinin syndrome)
Amyloidosis
Multiple myeloma and Waldenstrom’s macroglobulinemia

Question 5

Vascular Inflammation

Answer 5

Antibodies against endothelial cells or subendothelial layers
Neutrophils release oxygen radicals that damage the vacular tissue
Factor XII can also activate, forming a clot and initiating inflam

Question 6

Miscellaneous

Answer 6

Mechanical purpura: increased internal capillary pressure

Easy bruising syndrome (purpura simplex): spontaneous ecchymoses that appear on the thighs and upper arms

Question 7

Quantitative Platelet Disorders

Answer 7

Thrombocytopenia
Caused by immune destruction, non immune destruction, decreased production, dilutional thrombocytopenia
Thrombocytosis

Question 8

Thrombocytopenia Immune Destruction

Answer 8

Autoimmune response against plt by B cells
Can also damage megakaryocytes
Plt won’t be able to aggregate and be crosslinked since they keep getting destroyed
Drug induced thrombocytopenia and heparin induced (HIT) common

Question 9

Thrombocytopenia Non-Immune Destruction

Answer 9

MAHA (DIC, TTP, HUS)
Mechanical destruction (artificial heart valve)

Question 10

Thrombocytopenia Decreased Production

Answer 10

Can be caused by lots of things

Question 11

Dilutional Thrombocytopenia

Answer 11

Massive blood transfusion can significantly decrease plt counts
Platelet transfusions should be given to maintain count at 75

Question 12

Thrombocytosis

Answer 12

Myeloproliferative disorder
IDA
Vigorous exercise
Myelodysplastic syndrome

Question 13

Qualitative Platelet Disorders

Answer 13

Bernard Soulier Syndrome
Glanzmann's Thrombasthenia
Dense Granule Deficiency 
Grey Plt Syndrome
Defective Thromboxane A2 Synthesis

Question 14

Bernard Soulier Syndrome

Answer 14

Caused by a GPIb deficiency (symptoms identical to vWF disease)
Plts show abnormal aggregation reponse to ristocetin

Question 15

Glanzmann’s Thrombasthenia

Answer 15

Caused by lack of GPIIb/IIIa

Platelet aggregation absent except for ristocetin

Question 16

Dense Granule Deficiency

Answer 16

Heterogeneous group of disorders that all manifest with a lack of dense granules
Lack of ADP from dense granules impairs secondary platelet aggregation
Abnormal aggreagation because collagen is just flat

Question 17

Grey Platelet Syndrome

Answer 17

Characterized by a lack of alpha granules

Question 18

Defective Thromboxane A2 Synthesis

Answer 18

Can be caused by inhibition of COX-1 or defects in phospholipase A2
Similar platelet aggregation pattern to dense granule deficiency