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Platelet Aggregation

Item Value
Approval req'd? No, but only run by appointment, Contact Hematology at x3-1747
Available Stat? No
Test code AGGR
Test group Platelet function
Performed by Parnassus Hematology
In House Availability Run as needed, Monday - Friday day shift only
Patient Preparation Patient should be rested, fasting since midnight, and no smoking before blood collection. No caffeine and no alcohol for 48 hours prior to testing. Take only medication as directed by physician before testing.
Collection Instructions By appointment only, contact Hematology at x3-1747

Samples are only collected by Hematology techs.

Note:If aggregation testing using less than the full set of agonists is desired, including limited testing for response to aspirin or ADP-receptor antagonists, see "Additional Information" and note specific requests on requisition.
Container type Blue tops (x6) and Lavender top
Amount to Collect 20 mL blood
Sample type Citrated and EDTA anticoagulated whole blood
Preferred volume 20 mL blood
Min. Volume 17 mL blood
Normal range
Synonyms lumi-aggregation; platelet aggregation with luminescence; clopidogrel; plavix; aspirin; ASA
Stability Room temperature 3 hours.
Turn around times 1-3 days
Additional information An interpretation of this test by a laboratory physician will automatically be performed and billed for separately.

Measures the release of ATP in the presence of thrombin, collagen and ATP and examines the aggregation response to Thrombin, ADP, arachidonic acid, collagen, and ristocetin at various concentrations:

Agonist Concentration
Thrombin 1 Unit
ADP 5 µM
ADP 10 µM
Collagen 1 µg/mL
Collagen 5 µg/mL
Arachidonic Acid 0.5 mM
Ristocetin 1.0 mg/mL

A platelet count and pathologist evaluation of platelet morphology on a stained blood smear are required for the performance of this assay and will be ordered and separately charged.

If platelet aggregation is ordered without further specification, a full panel of agonists will be run and interpreted:
- If assessment of clopidogrel response is desired, specify "platelet aggregation for clopidogrel response." A 5 micromolar ADP study will be performed and interpreted.
- If assessment of aspirin response is desired, specify "platelet aggregation for aspirin response." 1 microgram/mL collagen and 5 microgram/mL collagen studies will be performed and interpreted.
- Other combinations of particular agonists can be specifically requested when a full panel of agonists is not needed; conferring with a hematology laboratory physician is requested in this circumstance x3-1747
CPT coding 85576
LOINC code 48805-6
Last Updated 3/3/2014 12:02 PM
Entry Number 749
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