Congenital Coagulopathies (Part II)

Question 1

Causes VWF activity to rise

Answer 1

Physical stress such as cold, exertion, or a child’s cry- ing or struggling during venipuncture

Question 2

T/F: vWF activity rises when the phlebotomist allows the tourniquet to remain tied for more than 1 minute before venipuncture and descends if the specimen is stored in the refrigerator before testing.

Answer 2

TRUE

Question 3

Concern over the poor reproducibility of results of the VWF:RCo assay has led to development of the

Answer 3

VWF collagen- binding (VWF:CB) assay.

Question 4

Rheumatoid factor and heterophile antibodies interfere to cause

Answer 4

False positive

Question 5

Specimen mishandling such as prolonged tourniquet application, plasma refrigeration, filtration, or ultracentrifugation lead to

Answer 5

False positives, false negatives, or false phenotypes such as misidentifying a type 1 as a type 2 VWD

Question 6

Mild bleeding may resolve with the use of localized measures, such as

Answer 6

Limb elevation, pressure, and application of ice packs

Question 7

PRICE is an athlete’s acronym for

Answer 7

for protection, rest, ice, compression, and elevation

Question 8

May respond to estrogen and desmopressin acetate, which trigger the release of VWF from storage organelles

Answer 8

Moderate bleeding

Question 9

is an antidiuretic hormone analog used to control incontinence in diabetes mellitus and bedwetting; release of VWF from storage organelles is a side effect

Answer 9

Desmopressin acetate

Question 10

Is consistently effective for type 1 and subtype 2M VWD and generally useful for subtype 2A.

Answer 10

DDAVP, or oral spray form, Stimate

Question 11

inhibit fibrinolysis and may help control bleeding when used alone or in conjunction with desmopressin acetate.

Answer 11

Lysine analogs e-aminocaproic acid and tranexamic acid

Question 12

For treatment of severe VWD (type 3) and subtype 2B, three commercially prepared human plasma-derived high- purity preparations are available that provide a mixture of VWF and coagulation FVIII:

Answer 12

Humate-P, Alphanate, and Wilate.

Question 13

Essential to determine whether the given amount produced the target level of VWF and to follow its degradation between doses

Answer 13

VWF:Ag assay

Question 14

Is a recombinant VWF that provides no accompanying factor VIII.

Answer 14

Vonvendi

Question 14

Are congenital single-factor deficiencies marked by anatomic soft tissue bleeding.

Answer 14

Hemophilias

Question 15

Congenital deficiency of factor VIII is called

Answer 15

Classic hemophilia or hemophilia A.

Question 16

Is two-chain, 285,000-Dalton protein translated from the X chromosome.

Answer 16

Factor VIII

Question 17

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

Answer 17

B domain

Question 18

Sometimes called the tenase complex, cleaves and activates coagulation factor X at a rate 10,000 times faster than free factor IXa can cleave factor X

Answer 18

VIIIA/IXa complex

Question 18

Sometimes called the tenase complex, cleaves and activates coagulation factor X at a rate 10,000 times faster than free factor IXa can cleave factor X

Answer 18

VIIIA/IXa complex

Question 19

T/F: VIII deteriorates in storage. Donor blood collected in standard citrate-dextrose-phosphate preservative provides 30 units/dL FVIII activity after 28 days’ storage or approximately 50 units/dL in leukodepleted donor blood.

Answer 19

TRUE

Question 20

Are exquisitely painful and cause temporary immobilization.

Answer 20

Acute joint bleeds

Question 21

Cause inflammation and eventual permanent loss of mobility, whereas bleeding into muscles may cause nerve compression injury, with first tempo- rary and then lasting disability

Answer 21

Chronic joint bleeds

Question 21

T/F: The severity of hemophilia A symptoms is inversely proportional to FVIII activity.

Answer 21

TRUE

Question 22

May transmit non-lipid viruses such as parvovirus B19 and hepatitis A virus

Answer 22

Human plasma-derived FVIII (pdFVIII)

Question 23

contain VWF, fibrinogen, and noncoagulant proteins in addition to FVIII and are used to treat VWD

Answer 23

Alphanate, Humate-P, and Wilate

Question 24

is used in many drug applications; it extends the rFVIII half-life to approximately 20 hours and reduces the infusion rate to approximately twice weekly.

Answer 24

PEGylation

Question 25

Generate inhibitor titers of 5 NBUs or less and their inhibitor titers do not increase significantly after FVIII administration

Answer 25

Low responders

Question 26

Generates inhibitor titers that exceed 5 NBUs ad their antibody titers

Answer 26

High responders

Question 27

Often experience cessation of bleeding on administration of large doses of FVIII concentrate and may be so maintained

Answer 27

Low responders

Question 28

May gain no benefit from FVIII concentrates and instead are treated with activated PCC (Auto-plex T or FEIBA), or rFVIIa (NovoSeven), all of which generate thrombin despite the presence of FVIII inhibitors

Answer 28

High responders

Question 29

Is caused by deficiency of factor IX (FIX), one of the vitamin K-dependent serine proteases

Answer 29

Hemophilia B, also called Christmas disease

Question 30

Is a substrate for both factors XIa and VIIa because it is cleaved by either to form dimeric factor IXa

Answer 30

Factor IX

Question 31

Reduces thrombin production and causes soft tissue anatomic bleeding that is indistinguishable from that in hemophilia A.

Answer 31

Factor IX deficiency

Question 32

Lab result for Hemophilia B:
PTT:
PT, TT, Fibrinogen:

Answer 32

PTT: Prolonged
PT, TT and Fibrinogen: Normal

Question 33

is a recombinant FIX concentrate (rFIX) grown in CHO cells in the absence of human or animal protein

Answer 33

BEnefix

Question 34

An autosomal dominant hemophilia with mild to moderate bleeding symptoms.

Answer 34

Factor XI deficiency

Question 35

T/F: The frequency and severity of bleeding episodes do not correlate with factor XI levels, and laboratory monitoring of treatment serves little pur- pose after the diagnosis is established

Answer 35

TRUE