Time Sensitive

Ordering Recommendation

Use to evaluate patients with suspected platelet dysfunction (inherited or acquired). Test includes ristocetin-induced platelet aggregation (RIPA). RIPA is not an initial test in the diagnosis of von Willebrand disease (VWD) and should be ordered in consultation with a coagulation specialist to distinguish between type 2 subtypes in patients diagnosed with VWD. A patient history form is required for testing; refer to Patient History for Platelet Aggregation Studies.

New York DOH Approval Status

This test is not New York state approved. There are no New York state-approved laboratories available. Submit a Non-Permitted Laboratory Request Form (NPL) to the NYDOH prior to collection of specimen. If NPL is approved by NYDOH, and sample is received at ARUP, testing will be performed.

Specimen Required

Patient Preparation

Instructions will be provided by the ARUP Hemostasis/Thrombosis lab upon receipt of Patient History for Platelet Aggregation Studies form.


Specimen collection to be scheduled by the ARUP Hemostasis/Thrombosis lab and performed at the ARUP Family Health Clinic.

Specimen Preparation

Performed by the ARUP Hemostasis/Thrombosis Lab.

Storage/Transport Temperature


Unacceptable Conditions

Specimens not scheduled by the ARUP Hemostasis/Thrombosis lab and not collected by ARUP.


A completed Patient History Form must be submitted and approved prior to scheduling specimen collection; refer to Ordering Recommendation section for Patient History Form link.


Ambient: 4 hours; Refrigerated: Unacceptable; Frozen: Unacceptable


Qualitative Aggregation




1-2 days

Reference Interval

Available Separately Components Reference Interval
No Platelet Aggregation Studies, ADP Normal
No Platelet Aggregation Studies, Collagen Normal
No Platelet Aggregation Studies, AA Normal
No Platelet Aggregation Studies, Ristocetin Normal

Interpretive Data

Compliance Category



Hotline History


CPT Codes

85576 x4


Component Test Code* Component Chart Name LOINC
0030001 Platelet Aggregation Studies, Additional 21027-8
0030005 Platelet Aggregation Studies, ADP 24377-4
0030020 Platelet Aggregation Studies, AA 24381-6
0030045 Platelet Aggregation Studies, Collagen 24379-0
0030255 Platelet Aggregation Studies, Ristocetin 24380-8
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • PFT
  • Platelet function assay
  • RIPA
  • Ristocetin Induced Platelet Aggregation
Platelet Aggregation Studies