RBC II Putthoff, Bleeding Disorders from defective platelet functions

Question 1

What are the classes of inherited disorders of platelet function

Answer 1

defects of adhesion
defects of aggregation
disorders of platelet secretion

Question 2

What is Bernard Soulier syndrome

Answer 2

defective adhesion of platelets to subendothelial matrix

Question 3

Where is the defect in Bernard Soulier

Answer 3

glycoprotein complex Ib-IX

R for vWF

Question 4

What is disorder has bleeding from defective platelet aggregation

Answer 4

Glanzmann thrombasthenia

Question 5

inheritance of glanzmann thrombasthenia

Answer 5

autosomal recessive

Question 6

Where is the defect in glanzmann thrombasthenia

Answer 6

dysfunction of glycoprotein IIb IIIA

does not aggregate in response to ADP, collagen, epinephrine, thrombin

Question 7

disorders of platelet secretion are chanracterized by what

Answer 7

defective release of certain mediators of platelet activation like thromboxane and ADP

Question 8

what are the 2 significant types of acquired defects of platelet function

Answer 8

aspirin and NSAID caused

related to uremia

Question 9

what activates fibrinogen to form clots

Answer 9

thrombin

Question 10

What factors are involved in intrinsic clotting pathyway

Answer 10

XII XI IX
X
thrombin and fibrin

Question 11

what factors are involved in extrinsic clotting pathway

Answer 11

VII TF
X
thrombin, fibrin

Question 12

how do most patients with from coagulation factor defects present?

Answer 12

large post-traumatic ecchymoses or hematomas or prolonged bleeding

Question 13

where are sites of bleeding from factor defect

Answer 13

GI and urinary tracts

weight bearing joints

Question 14

What are the most common inherited disorders of coagulation pathway

Answer 14

VIII (hemophilia A)
IX (hemophilia B)
vWF

Question 15

what is characteristic of acquired deficiencies of coagulation factors

Answer 15

multiple factors

decreased protein synthesis or shortened half life

Question 16

vit K deficiency affects coagulation how

Answer 16

impaired synthesis of factors II, VII IX X and protein C

Question 17

how does liver disease affect coagulation factors

Answer 17

many are made in the liver

Question 18

how are coagulation factors affected in DIC

Answer 18

multiple coagulation factors are consumed and deficient

Question 19

what cause single factor acquired deficiency

Answer 19

autoAb

very rare

Question 20

Where is factor VIII made

Answer 20

sinusoidal endothelial cells and kupffer cells in the liver

Question 21

where is vWF produced

Answer 21

endothelial cells and megakaryocytes

Question 22

what is the role of vWF

Answer 22

binds factor VIII and increases its circulation half life

promotes adhesion of platelets to subendothelial matrix thorugh GpIb-IX

Question 23

where is vWF stored

Answer 23

alpha granules of megakaryocyts

Question 24

what is the most common inherited bleeding disorder of humans in US

Answer 24

vWF disease

Question 25

what are signs of vw disease

Answer 25

mild bleeding

spontaneous bleeding from mucous membranes, excessive wound bleeding or menorrhagia

Question 26

what is inheritance pattern of vw disease

Answer 26

autosomal dominant but some are autosomal recessive

Question 27

what else can vWF bind to besides VIII

Answer 27

GpIIb IIIa intefrins

Question 28

how is vwF measured

Answer 28

ristocetin agglutination test

measured with aggregaometer

Question 29

What types vw are assoc with quantitative defects in vwF

Answer 29

type I and III

Question 30

characteristics type I VW disease

Answer 30

autosomal dominant

mild to mod deficiency

Question 31

describe type III VW disease

Answer 31

autosomal recessive with very low levels vWF and severe manifestations

Question 32

what causes type 3 VW disease

Answer 32

deletions or frameshift mutations involving both alleles

Question 33

is type 2 VW disease characterized by quantitative or qualitative defects

Answer 33

qualitative

Question 34

what is most common subtype type 2 VW disease

Answer 34

2A

Question 35

inheritance 2A VW disease

Answer 35

autosomal dominant

missense mutations

Question 36

how common is type 2 VW disease

Answer 36

25% of all cases assoc with mild-moderate bleeding

Question 37

are platelet counts low in VW disease

Answer 37

no

Question 38

what will vwD cause a deficiency in

Answer 38

factor VIII levels

Question 39

are PT and PTT normal in vw D

Answer 39

prolonged PTT in type I and 3

Question 40

what is Tx for mild vwD

Answer 40

desmospressin which stimulates vWF release

or infusions of VIII and vWF