Heparin-PF4 IgG Antibody, Serum
Use
This test is useful for detecting IgG antibodies against heparin/platelet factor 4 complexes involved in the pathogenesis of immune-mediated type II heparin-induced thrombocytopenia (HIT). It is also used for the detection of thrombocytopenia and thrombosis occurring after SARS-CoV-2 adenovirus vector vaccine. Recognizing these antibodies can aid in the diagnosis of HIT, autoimmune HIT, and HIT-like syndromes following specific surgeries or infections.
Special Instructions
Fasting for 8 hours is preferred but not required for the patient prior to specimen collection. The specimen should be centrifuged, and serum aliquoted into a plastic vial. Electronic ordering is preferable; if unavailable, use the Coagulation Test Request (T753) form.
Limitations
The specificity of positive results for clinical HIT diagnosis is low. A positive result indicates the presence of H/PF4 complex antibodies, but does not confirm HIT. Up to 10% of patients with clinical HIT may have a negative result, thus clinical findings should guide diagnosis. The presence of H/PF4 antibodies increases the risk of HIT, but data on relative risk is limited.
New York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 73818-7
- 73817-9
- 73819-5
- 73816-1
- 73818-7
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red top, Plastic vial
Collection Instructions
Centrifuge, aliquot serum into a plastic vial.
Patient Preparation
Fasting: 8 hours, preferred but not required
Causes for Rejection
Gross hemolysis, Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Refrigerated | 7 days |
| Frozen | 2 years |