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Epic Code LAB2111147 Platelet Aggregation Studies

Important Note

Must be scheduled in advance by a healthcare provider by calling 616.267.2740, Monday - Friday, 8 a.m. - 3:30 p.m.

Patients for platelet aggregation tests should be resting, fasting, non-smoking, and should not be pregnant. Patients should avoid taking any prescription or over the counter medications known to affect platelet function for ten (10) days to two (2) weeks prior to the test. Click for a list of medications with known anti-platelet effects

Platelet aggregation testing is performed for scheduled patients on Monday - Thursday from 7:30 a.m. - 9:30 a.m. at the 35 Michigan Street Laboratory. Please click the link for directions to the lab.

COLLECTION NOTE: MULTIPLE TUBES FOR ONE TEST

There is currently a nationwide shortage of this tube. Please take steps to ensure specimen integrity to reduce recollection. Specimen Tube Shortage (link)

Test Name Alias

Platelet Aggregation Studies | Plt Aggregation Studies | 8429

Interface Order Alias

1230713

Quick Collect

LOOK + LOOK

Clinical Information

Useful for evaluating platelet dysfunction due to congenital, qualitative platelet disorders.  Platelet aggregation testing is optimized in this laboratory to detect congenital abnormalities such as Glanzmann thrombasthenia, Bernard Soulier disease, Wiscott Aldrich syndrome, aspirin-like defect, some subtypes of platelet storage pool disorders, and some types of von Willebrand disease.  It is not designed for medication effect monitoring or cardiovascular risk assessment.  Platelet aggregation is determined by measuring changes in the optical density of stirred platelet rich plasma after an aggregating agent is added.  The test employs the use of light transmission aggregometry and percent maximum aggregation as the quantitative measurement.  The slope and shape of the curve is interpreted as well.

 

Contraindications: Not indicated for patients taking medications that are known to inhibit platelet function. Medications which can inhibit platelet function include aspirin and anti-inflammatory drugs, anti-platelet drugs which include clopidogrel and imidazole. Yet, there are numerous other medications whose principal role is not to inhibit platelet function but nonetheless can do so e.g. antibiotics, anti-depressants, beta-blockers etc. Please contact the ordering physician before discontinuing any medications.

 

Platelet aggregation testing may require a coagulation consult with a pathologist prior to scheduling.

 

Testing recommendations:

  • Evaluation of Plavix or Aspirin order Verify Now P2Y12 assay for Antiplatelet Effect: LAB3326 or Verify Now Assay for Aspirin Effect: LAB3325
  • For platelet screening order Platelet Function Assay (PFA): LAB318

Ordering Instructions

Must be scheduled in advance by a healthcare provider.

Icons & Photos

 x8 Blue

Collection Instructions

Specimen Type: Whole Blood

Container/Tube:  8 x 2.7 mL blue top (3.2% Sodium Citrate) and 1 Lavender top (EDTA, 3 mL)

Collection Instructions:

 

Fasting specimen preferred, but not required.

 

Patients for platelet aggregation tests should be resting, fasting, non-smoking, and should not be pregnant. Patients should avoid taking any prescription or over the counter medications known to affect platelet function for ten (10) days to two (2) weeks prior to the test. 

 

Phlebotomy will draw syringes of venous blood from the patient using a 19-21 gauge needle.

  • A clean venipuncture should be performed and blood should not be drawn from indwelling needles or catheters.
  • Fill EIGHT 2.7 mL citrated (blue stoppered) tubes and ONE EDTA (lavender) tube for each patient being drawn.
  • Remove the stoppers from the citrate and EDTA tubes.
  • Remove the needle from the syringe.
  • Gently dispense 2.7 mL whole blood from the syringe into each of the citrated tubes and whole blood into the EDTA tube.
  • Replace stoppers tightly.
  • Mix all tubes gently by inversion 5 - 10 times.
  • Transport specimens to the lab immediately after collection.
  • Do not send through the pneumatic tube system.
  • Specimens must be hand delivered to the laboratory.

 

Detailed instructions (link): Anticoagulant Correction for High Hematocrit

Processing Instructions (Laboratory, Outpatient or Off-site collection)

Cannot be collected off-site.

Rejection Criteria

  • Hemolysis

Specimen Stability

Ambient: 4 hours post-collection

Refrigerated: Not acceptable

Frozen: Not acceptable

Laboratory Retention: 24 hours

Test Frequency

Available Monday through Thursday, Downtown Campus only. Usual TAT 3 - 5 days.

Performed for scheduled patients Monday - Thursday from 7:30 a.m. to 9:30 a.m.

Reference Range

Normal Platelet Aggregation response to platelet agonists.

 

If agonists are decreased (ADP 20 µm, ADP 2.5 µm, Ristocetin 1500 µg/mL, Epinephrine 300 µm, Collagen 10 µg/mL, Arachidonic Acid 500 µg/mL), or increased Ristocetin 500 µg/mL then a pathologist review of results with interpretation will be performed

Performing Department

Coagulation

Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI

Methodology

Human platelet aggregation measured by absorbance using platelet rich plasma.

CPT

Arachidonic Acid, aggregation: CPT Code: 85576
ADP, aggregation: CPT Code: 85576
ADP, aggregation: CPT Code: 85576
Collagen, aggregation: CPT Code: 85576
Epinephrine, aggregation CPT Code: 85576
Ristocetin, aggregation: CPT Code: 85576
Ristocetin, aggregation: CPT Code: 85576
Platelet Count: 85049
Hematocrit: 85014
Pathologist interpretation: CPT Code: 85576 -26

CDM Code

Unavailable

Epic Test ID

1230101991, 1230101991, 1230102115

LOINC

ADP 20 µM 33518-2

ADP 2.5 µM 33519-0

Ristocetin 1500 µg/mL 33522-4

Ristocetin 500 µg/mL 33523-2

Arachidonic Acid 500 µg/mL 24381-6

Collagen 10 µg/mL 24379-0

Epinephrine 300 µM 24378-2

Platelet: 777-3

Hct: 4544-3

Reviewed Date

3/23/2023