Sign in →

Test Code PFA Platelet Function Analysis, Blood

Important Note

Effective 1/6/2025:  Testing not available.

The PFA-100 analyzer is down and will require off-site repairs by our vendor. During this time an alternative test will not be available.

Specimen integrity requirements for platelet aggregometry and PFA-100 testing do not allow specimen transportation to reference labs. A similar screening assay for inherited platelet function disorders will not be available at Bronson until the analyzer is repaired by our vendor.

If there is strong pre-test probability for Glanzmann thrombasthenia, Bernard-Soulier syndrome, or collagen receptor deficiency then consider testing for Platelet Surface Glycoprotein by Flow Cytometry (Mayo test code: PLAFL). Please refer the Bronson Lab Test Catalog for additional information and forms required for this testing. Platelet Surface Glycoprotein by Flow Cytometry, Blood - Bronson Laboratory Services

The use of Thromboelastography (TEG) testing to assess inherited platelet disorders is not well-validated and is not recommended. TEG testing does provide valuable information on platelet function in select circumstances (trauma, post partum hemorrhage, surgery) and can detect platelet inhibitors (clopidogrel, aspiren) through a platelet mapping cartridge. We do not recommend the use of TEG to replace PFA-100.

Methodology

Siemens PFA Analyzer: Adhesion and aggregation response of platelets to Epinephrine and ADP 

 

Testing begins wtih the Collagen/Epinephrine (EPI) test, which can detect platelet dysfunction induced by intrinsic platelet defects, von Willebrand disease or exposure to platelet inhibiting medications.  If the EPI test is elevated,  the Collagen/ADP test is reflex ordered.   The ADP test is used to indicate if an abnormal result obtained with the EPI test may have been caused by the effect of acetyl salicylic acid (ASA) or medications containing (ASA).

Performing Laboratory

Bronson Methodist Hospital Laboratory-Coagulation Department

Specimen Requirements

Specimen must be tested within 4 hours of draw.

 

Specimen Type: Whole blood

 

Container/Tube:     2-mL Greiner Vacuette light blue citrate tubes

                                1.8 ml or 2.7 ml BD Vacutainer tubes are also acceptable

 

Specimen Volume:  2 full tubes

 

Collection Instructions:

  • Tubes must be full to fill line.
  • Gently invert 5 to 10 times to mix blood.
  • Do not centrifuge. 
  • Do not refrigerate or freeze specimen.
  • If collected through a blood collection set (butterfly), a discard tube must first be drawn to eliminate dead space from tubing.
  • Causes for rejection include tube not filled to line, clotted specimen, refrigerated or frozen specimen.

See "Important Note" at top of this page for additional information on laboratory site specific collection options. 

 

Specimen Transport Temperature

Ambient YES

Refrigerate NO

Frozen NO

Reference Values

Collagen/Epinephrine Reference Range:   70 - 170 seconds.   

If the result is <171 seconds, no further testing is indicted and the following comment is reported

Platelet function appears normal. If patient history or physical examination gives strong indication of a bleeding disorder, suggest repeat testing for confirmation. If repeat results remain normal, consider other causes of bleeding.

If the result is >170 seconds, the Collagen/ADP test is run.

 

Collagen/ADP Reference Range:  54-121 seconds.

If the result is <122 seconds the following comment is reported: 

Platelet function appears abnormal. This pattern is most commonly seen in patients with won Willebrand’s disease or congenital platelet defects. When evaluated in conjunction with clinical history and other test findings, this may indicate the need for further diagnostic testing.

If the result is <122, the following comment is reported:

Results suggest drug induced platelet dysfunction. This is most commonly seen after aspirin ingestion.

 

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

85576 X 1 if only EPI test is run

85576 x 2 if reflex to ADP test is also run