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Epic Code LAB318 Platelet Function Assay (PFA)

Important Note

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

Testing must be performed within 4 hours of collection.

  • PFAs for regional hospitals should be collected at hospital site draw station and not at offsight blood draw locations due to time constraints. Courier Schedules must be considered.

Lavender top must be refrigerated - Blue top must be ambient.

Test Name Alias

Platelet Function Assay | Plt Function Assay | PFA | 4323

Interface Order Alias

10766

Quick Collect

LOOK+LOOK

Clinical Information

The PFA-100® system is an instrument and test cartridge system in which the process of platelet adhesion and aggregation following a vascular injury is simulated in vitro. Platelet dysfunction detected by the PFA-100® may be acquired, inherited, or induced by platelet inhibiting agents. Common causes of platelet dysfunction include uremia, von Willebrand disease, and exposure to agents, such as acetyl salicylic acid (Aspirin).

 

Prolongation of closure times may be indicative of medication effect, such as aspirin (typically prolonged Collagen/EPI and normal or borderline prolonged Collagen/ADP), NSAIDS and others, (including antibiotics, cardiovascular drugs), recent fatty acid ingestion, uremia, low hematocrit (<35%), low platelet count (<150K), von Willebrand disease or platelet function disorders.  Von Willebrand factor testing and/or platelet aggregation studies may be indicated for further evaluation if both Collagen/EPI and Collagen/ADP are prolonged, correlate clinically.

Icons & Photos

x2 + 

Collection Instructions

Specimen Collection: Blood

 

Container(s): 3.2% Na Citrate Tube (blue top) AND 3.0 mL EDTA Lavender top

Preferred Volume to Collect: 2 x 2.7 mL tubes AND 3.0 mL (lav top)

Minimum Volume to Collect: 2 x 2.7 mL tubes AND 0.5 mL (lav top)

Capillary collect ok: No

Microtainer acceptable: No

 

Collection Instructions:

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

Processed Specimen: Whole Blood

 

Centrifuge/Spin: No

Aliquot: No

 

Processing Instructions:

  • Testing must be performed within 4 hours of collection
  • DO NOT refrigerate/freeze or centrifuge blue top specimen(s)
  • Lavender may be refrigerated to extend specimen stability 
  • Please call for STAT courier pick-up and direct specimen to Spectrum Health Regional Laboratory (35 Michigan, Grand Rapids)

Transport Temperature:

  • Ambient (blue top)
  • Ambient or Refrigerated (lavender top)

Rejection Criteria

  • Hemolysis
  • Refrigerated or frozen specimen (blue top)
  • Under/over filled tubes

  • Platelet Count <50,000/mL

  • HCT < 30 %

Specimen Stability

Blue top:

Ambient:  4 hours (whole blood state)

Refrigerate: not acceptable

Frozen: not acceptable

Laboratory Retention: 24 hours

Lavender top:

Ambient: 12 hours

Refrigerate: 24 hours

Laboratory Retention: 72 hours

Reflex Information

Link: Mandatory reflex approved by MEC

Test Frequency

Available 24 hours, usual TAT 4 hours.

Reference Range

PFA Collagen/ADP
60 – 120 second(s)

 

PFA Collagen/Epi
80 – 180 second(s)

 

Abnormally high results may be due to: medication effect, such as aspirin (typically prolonged Collagen/EPI and normal or borderline prolonged Collagen/ADP), NSAIDS and others, (including antibiotics, cardiovascular drugs), recent fatty acid ingestion, uremia, low hematocrit (<35%), low platelet count (<150K), von Willebrand disease or platelet function disorders.

Performing Department

Coagulation

Performing Department Laboratory Location

Corewell Health Reference Laboratory, Grand Rapids, MI

Methodology

The PFA-100® is an instrument and test cartridge system in which the process of platelet adhesion and aggregation is simulated in vitro mimicking injured endothelium. The time necessary to block a membrane coated with collagen and epinephrine or collagen and ADP is measured and called closure time.

CPT

85049, 85014, 85014, 85049

CDM Code

3058504901, 3058501401, 3058501401, 3058504901

Epic Test ID

1230101982

LOINC

PFA Collagen/Epi: 24471-5

PFA Collagen/ADP: 24472-3

PFA Hematocrit: 4544-3

PFA Platelet Cnt: 777-3

Mayo Access Code

SHO4323

Reviewed Date

3/23/2023