Sign in →

Test Code HITABM Heparin-PF4 IgG Antibody (HIT), Serum

Additional Codes



Secondary ID


Useful For

Detection of IgG antibodies directed against heparin/platelet factor 4 complexes that are implicated in the pathogenesis of immune-mediated type II heparin-induced thrombocytopenia (HIT-II).


Clinical picture of HIT type II:

-In patients not previously exposed to heparin

-Decrease in platelet count (thrombocytopenia) of 50% or more from baseline or postoperative peak

-Onset of thrombocytopenia beginning approximately 5 to 10 days after initiation of heparin this may or may not be associated with new or progressive thrombosis in patients treated with heparin


Patients previously exposed to heparin (especially within the preceding 100 days), in addition to the above findings, the onset of thrombocytopenia could occur within 24 to 48 hours after reexposure to heparin

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Reporting Name

Heparin-PF4 IgG Ab (HIT), S

Specimen Type

Serum Red

Specimen Required

Collection Container/Tube: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen (preferred) 14 days
  Refrigerated  48 hours

Reject Due To

Gross hemolysis Reject
Gross lipemia Reject

Reference Values




HIT Interpretation:


Day(s) and Time(s) Performed

Monday through Sunday, Varies

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
HITIG Heparin-PF4 IgG Ab (HIT), S In Process


Result ID Test Result Name Result LOINC Value
46915 HIT ELISA 73818-7
21468 Heparin Inhibition 73817-9
21469 HIT Interpretation 73819-5
21470 HIT Comment 73816-1