Hemorrhagic Disorders and Laboratory Asssessment

Question 1

Bleeding from a single location

Answer 1

localized bleeding or localized hemorrhage

Question 2

Bleeding from multiple sites, spontaneous and recurring bleeds, or a hemorrhage that requires physical intervention

Answer 2

generalized bleeding

Question 3

skin may appear as petechiae, red pinpoint spots (Figure 38.1A); purpura, purple skin lesions greater than 3 mm diameter (Figure 38.1B); or ecchymoses (bruises) greater than 1 cm, typically seen after trauma

Answer 3

mucocutaneous bleeding

Question 4

Anemia associated with chronic bleeding or a hemolytic anemia; bone marrow response

Answer 4

Hemoglobin, hematocrit; reticulocyte count

Question 5

assess Thrombocytopenia

Answer 5

platelet count

Question 6

assess Clotting time prolonged in deficiencies of factors II (prothrombin), V, VII, or X

Answer 6

PROTHROMBIN TIME

Question 7

Clotting time prolonged in deficiencies of all factors except VII and XIII

Answer 7

Partial thromboplastin time (PTT)

Question 8

Prolonged by unfractionated heparin therapy, dysfibrinogenemia, hypofibrinogenemia, and afibrinogenemia; qualitative

Answer 8

Thrombin time (TT)

Question 9

Reduced in dysfibrinogenemia, hypofibrinogenemia, and afibrinogenemia; quantitative result

Answer 9

Fibrinogen assay (FG)

Question 10

If a patient’s bleeding episodes begin after childhood, are associated with some disease or physical trauma, and are not duplicated in relatives

Answer 10

ACQUIRED

Question 11

uncommon, occur- ring in fewer than 1 per 100 people, and are usually diagnosed in infancy or during the first years of life.

Answer 11

Congenital hemorrhagic disorders

Question 12

Defined as any single or multiple coagulation factor or platelet deficiency, and TIC is triggered by the combination of injury-related acute inflammation, hypo- thermia, acidosis, and hypoperfusion (poor distribution of blood to tissues associated with low blood pressure), all of which are elements of systemic shock

Answer 12

Coagulopathy

Question 13

ADAMTS13

Answer 13

a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13;

Question 14

15 to 20 mL cryoprecipitate unit provide

Answer 14

150-250 mg of fibrinogen

Question 15

A target fibrinogen level of should be maintained,

Answer 15

100 mg/dL

Question 16

Enlarged and collat- eral esophageal vessels called

Answer 16

esophageal varices

Question 17

unaffected by standard unfractionated heparin therapy and can be used to assess fibrinogen function even when there is heparin in the specimen.

Answer 17

reptilase time test

Question 18

Acquired autoantibodies that specifically inhibit factors

Answer 18

II (pro- thrombin), V, VIII, IX, and XIII and VWF

Question 19

confirm the presence of the inhibitor.

Answer 19

Clot-based mixing studies

Question 20

early rapid loss of factor VIII activity, residual activity remains, which indicates that the reaction has reached equilibrium.

Answer 20

type II kinetics

Question 21

Quantitation of autoanti-VIII inhibitor is accomplished us- ing the

Answer 21

Nijmegen-Bethesda assay

Question 22

Autoanti-factor XIII has been documented in patients receiving isoniazid treatment

Answer 22

tuberculosis

Question 23

most prevalent inherited mucocutaneous bleed- ing disorder

Answer 23

VWD

Question 24

Domain A supports a receptor site for collagen and a binding site (ligand) for platelet receptor

Answer 24

Glycoprotein (GP) Ib/IX/V and heparin

Question 25

Domain C provides a site that binds platelet receptor

Answer 25

GPIIb/IIIa

Question 26

domain D provides the carrier site for

Answer 26

factor VIII

Question 27

D'D3

Answer 27

FVIII

Question 28

A1

Answer 28

GP1B

Question 29

A2

Answer 29

ADAMTS13

Question 30

A3

Answer 30

COLLAGEN

Question 31

C1-C6

Answer 31

GPIIB/IIIA

Question 32

Customary designation for the combination of factor VIII and VWF.

Answer 32

FVIII/VWF

Question 33

Procoagulant factor VIII, transported on VWF. Factor VIII binds activated factor IX to form the complex of VIIIa-IXa, which digests and activates factor X. Factor VIII deficiency is called

Answer 33

HEMOPHILIA A

Question 34

Epitope that is the antigenic target for the VWF immunoassay.

Answer 34

VWF:Ag

Question 35

Factor VIII coagulant activity as measured in a clot- based factor assay.

Answer 35

FVIII:C

Question 36

Quantitative ristocetin cofactor activity, also called

Answer 36

VWF activity

Question 37

quantitative VWF deficiency caused by one of several autosomal domi- nant frameshifts, nonsense mutations, or deletions that may occur anywhere in the VWF gene.

Answer 37

type 1

Question 38

qualitative VWF abnormalities. VWF levels may be normal or moderately decreased, but VWF function is consistently reduced.

Answer 38

type 2

Question 39

which arises from well-characterized autosomal dominant point mutations in the A2 and D1 structural domains of the VWF molecule.

Answer 39

subtype 2a

Question 40

mutations render VWF susceptible to increased proteoly- sis by ADAMTS13, which leads to a predominance of small- molecular-weight plasma multimers

Answer 40

subtype 2a

Question 41

mutations within the A1 domain raise the affinity of VWF for platelet GPIb/IX/V, its customary binding site; these are hence “gain-of-function” muta- tions.

Answer 41

subtype 2b

Question 42

A platelet mutation that raises GPIb affinity for normal HMW-VWF multimers creates a clinically similar disorder called

Answer 42

platelet-type VWD (PT-VWD) or pseudo-VWD.

Question 43

qualitative VWF variant that possesses poor platelet receptor binding despite generating a normal multimeric distri- bution pattern in electrophoresis

Answer 43

subtype 2m

Question 44

autosomal VWF gene missense mutation in the D9 domain impairs the protein’s factor VIII binding site function.

Answer 44

subtype 2N

Question 45

“Nullallele”VWFgenetrans- lation or deletion mutations that may occur anywhere on the gene produce severe mucocutaneous and anatomic hemorrhage in compound heterozygotes or, in consanguinity, homozygotes.

Answer 45

type 3

Question 46

most prominent mem- ber of the primary VWD laboratory profile

Answer 46

quantitative VWF:Ag assay

Question 47

The traditional VWF:RCo assay employs

Answer 47

ristocetin

Question 48

added to in vitro patient plasma where it unfolds the VWF molecule and reduces repelling negative charges, enabling HMW-VWF multimers to bind reagent platelet membrane GPIb/IX/V re- ceptors.

Answer 48

ristocetin

Question 49

The VWF:RCo assay, typically performed using a

Answer 49

platelet aggregometer,

Question 50

PRICE

Answer 50

protection, rest, ice, com- pression, and elevation

Question 51

When the coagulation cascade is activated, thrombin cleaves plasma FVIII and releases a large polypeptide called the

Answer 51

B domain