Test Code LAB5387 Heparin-PF4 IgG Antibody, Serum
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, spontaneous heparin platelet-factor 4 IgG antibody, and thrombocytopenia and thrombosis occurring after SARS-CoV2 adenovirus vector vaccine
Reporting Name
Heparin-PF4 IgG Ab (HIT), SSpecimen Type
Serum RedSpecimen Required
Patient Preparation: Fasting is preferred but not required
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Stability Information: Frozen (preferred) 2 years/Refrigerate 7 days
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Frozen (preferred) | ||
Refrigerated | 7 days |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Reference Values
HIT ELISA:
<0.400
HIT Interpretation:
Negative
Supportive Data
The IgG human platelet factor 4 (H/PF4) enzyme-linked immunosorbent assay (ELISA) was compared with both the IgGAM H/PF4 ELISA (GTI Immucor) and the heparin-dependent platelet serotonin release assay (SRA) (Quest Diagnostics and Wisconsin Blood Center) in 208 patients. Assuming the SRA as the gold standard, the data were analyzed to determine the sensitivity of the ELISA assays for a positive SRA. Of the 208 patients tested, 49 had a positive SRA. With the IgGAM H/PF4 ELISA, 47/49 were positive (sensitivity 96%); with the IgG H/PF4 ELISA, 45 were positive (sensitivity 92%). Of those that tested negative with the SRA (n=159), 67 (42%) tested positive with the IgGAM H/PF4 ELISA, 37 (23%) tested positive with the IgG H/PF4 ELISA. (Mayo validation data)
In order to determine possible cross-reactivity between the target antigen and antibodies other than heparin-associated antibodies, 68 samples containing a variety of antibodies that included known antibodies to platelet alloantigens, platelet autoantibodies, antibodies to HLA class I and antirheumatoid factor were tested in this assay and none were found to cross react with the target antigen immobilized in the microwells.
Day(s) Performed
Monday through Sunday
Report Available
1 to 3 daysSpecimen Retention Time
7 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
86022
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
HITIG | Heparin-PF4 IgG Ab (HIT), S | 73818-7 |
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 |
Forms
If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.