Platelet AGGREGOMETRY

Question 1

Platelet Rich Plasma was measured using a specialized photometer

Answer 1

LIGHT TRANSMITTANCE AGGREGOMETER

Question 2

What anticoagulant used in Platelet rich plasma?

Answer 2

Sodium citrate-anticoagulated blood

Question 3

What is required to produce a sufficient PRP?

Answer 3

Requires 9-12mL of WHOLE BLOOD

Question 4

Normal Value of PRP

Answer 4

plasma with platelet count of 200,000-300,000/μL

Question 5

T/F. In PRP, Specimen must be test within 4 HOURS of collection to avoid IN VIVO platelet activation & loss of normal activity.

Answer 5

False, Specimen must be test within 4 HOURS of collection to avoid IN VITRO platelet activation & loss of normal activity.

Question 6

T/F. In PRP, If More clot/light pass through = More or high transmittance

Answer 6

True

Question 7

Whole Blood is measured by?

Answer 7

ELECTRICAL IMPEDANCE

Question 8

T/F. Increase impedance is DIRECTLY PROPORTIONAL to platelet aggregation (More blocking = High transmittance)

Answer 8

True

Question 9

What anticoagulant and temperature needed in Whole Blood?

Answer 9

Specimen is collected in 3.2% sodium citrate & held
at 15° C to 25° C until testing.

Question 10

T/F. In Whole blood, Aggregometry should be started immediately and must be completed within 4 hours of specimen collection (for undiminished ex vivo platelet activity).

Answer 10

True

Question 11

T/F. Most specimens for whole blood aggregometry are mixed 1:2 with normal saline before testing, although if the platelet count is less than 100,000/mL the specimen is tested undiluted.

Answer 11

False, Most specimens for whole blood aggregometry are mixed 1:1 with normal saline before testing, although if the platelet count is less than 100,000/mL the specimen is tested undiluted.

Question 12

Diagnosis of platelet dysfunction

Answer 12

Platelet Lumiaggregometry

Question 13

Simultaneous measurement of platelet aggregation & secretion of ATP from activated platelet dense granules

Answer 13

Platelet Lumiaggregometry

Question 14

Agonists used to activate platelets

Answer 14

Thrombin or Synthetic TRAP (Thrombin-Receptor-Activating Peptide),
ADP (Adenosine Diphosphate),
Epinephrine,
Collagen,
Arachidonic Acid &
Ristocetin

Question 15

These platelet agonists are used to test for abnormalities in specific membrane binding sites

Answer 15

Thrombin or Synthetic TRAP (Thrombin-Receptor-Activating Peptide),
ADP (Adenosine Diphosphate),
Epinephrine,
Collagen,
Arachidonic Acid &
Ristocetin

Question 16

used to check for deficiencies in the eicosanoid synthesis pathway

Answer 16

Arachidonic Acid

Question 17

used to check for abnormalities of plasma VWF in VWD

Answer 17

Ristocetin