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Test Code HEPPF4 Heparin Platelet Factor 4 (HIT Screen) with Reflex to (SRA)

Clinical Information

Detection of heparin-dependent platelet antibodies.

Synonym

  • PF4IGP

Specimen Required

Preferred Container/Tube: Red Top
Acceptable Container/Tube: Red Top
Specimen Volume: 2 - 2mL serum aliquots
Specimen Minimum Volume: 2 - 1mL serum aliquots

Specimen Collection Information

For Outreach other than OSU Patient Service Centers: Samples must be processed and received frozen/must remain frozen in transit.

For OSU Patient Service Centers: Send at 2-8° Celsius  

All Locations: When sending  serum, allow the sample to clot completely then centrifuge. Samples must be clearly marked as serum.

Specimen Stability Information

Ambient: Must be tested immediately
Refrigerated: 48 hours
Frozen: Serum: removed from the cells and frozen at -20°C or ideally -70°C.

Rejected Due To

  • Serum gel/SST not acceptable
  • Hemolysis

Testing Algorithm

If  PF4 IgG OD is >0.399 and % Heparin Inhibition is >50, then the Serotonin Release Assay (SRA), Unfractionated Heparin (LABYSRA) will be performed at an additional charge.

Reflex Tests

Reporting Name Available Separately Always Reported
Serotonin Release Assay (SRA), Unfractionated Heparin Yes No

Reference Values

PF4 IgG OD: <0.400
% Heparin Inhibition: <50

Cautions

The heparin antibody assay is intended as a screening test and should not be relied upon solely to establish the diagnosis of heparin-induced thrombocytopenia. The decision to discontinue heparin therapy is a clinical one and should not be delayed due to a pending HIT antibody test or serotonin-release assay.

Method Description

Enzyme-linked immunosorbent assay (ELISA), IgG

Performing Lab

Clinical Lab UH

Day(s) Performed

Monday through Friday (excludes OSU holidays)

Report Available

Same day/1 day

Reporting Name

Heparin Platelet Factor 4 (HIT Screen) With Reflex To SRA

CPT Code Information

86022