Home Test Search Results Heparin Antibody (HIT) Functional Confirmation
Heparin Antibody (HIT) Functional Confirmation


Up to 5 percent of patients receiving heparin develop heparin-induced thrombocytopenia (HIT), a life-threatening complication that can occur following exposure to heparin, regardless of the dose, schedule, or route of administration. The mortality rate can be as high as 20 percent; with early diagnosis, mortality rates have been reported as low as 2 percent. Ruling out HIT quickly can achieve both significant cost savings and experience better patient outcomes. Screening assays for HIT antibodies typically have high sensitivity, but low specificity, and positive results should be confirmed with a more specific functional assay to assess the ability of antibodies detected in screening tests to activate platelets.

STAT: < 24 hours (M-F)


Draw Tube: Red Top

Sample Type: Serum


Specimen Requirements

Sample Type Volume Required Minimum Volume Stability
PREFERRED Serum 1mL 0.5mL Room Temp.: 7 days
Refrigerated: 7 days
Frozen (-20C): 1 month
Frozen (-80C): 6 months
ALTERNATIVE Citrated Plasma 1mL - Frozen (-20C): 1 month
Frozen (-80C): 6 months
REJECTION CRITERIA Sample contamination; sample compromised

General Information

STAT TAT < 24 hours (M-F)
STAT TAT Performance > 90% of results released in 24 hours
ROUTINE TAT < 24 hours (M-F)
ALTERNATIVE NAMES Washed Platelet Heparin Induced Platelet Activation, WP-HIPA, Washed Platelet HIPA, SRA (equivalent)
DESCRIPTION Functional assay detecting antibodies in serum capable of activating platelets in the presence of heparin. Briefly, washed platelets from pre-screened donors are incubated with patient serum in the presence of various concentrations of heparin and platelet activation measured.
NORMAL RANGE Negative (< 20% activation)

1. Linkins LA et al. Treatment and prevention of heparin-induced thrombocytopenia: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012; 141(2 Suppl):e495S-530S.
2. Multz AS et al. The Management of Suspected Heparin-Induced Thrombocytopenia in US Hospitals. Clin Appl Thromb Hemost. 2012; 20(1):68-72.
3. Warkentin TE et al. Laboratory testing for the antibodies that cause heparin-induced thrombocytopenia: how much class do we need? J Lab Clin Med. 200; 146(6):341-346.
4. Hess CN et al. Antithrombotic therapy in heparin-induced thrombocytopenia: guidelines translated for the clinician. J Thromb Thrombolysis. 2012; 34(4):552-561.
5. Cuker A et al. Predictive value of the 4Ts scoring system for heparin-induced thrombocytopenia: a systematic review and meta-analysis. Blood. 2012; 120(20):4160-4167.

SAMPLE REPORT Upon request

Test Codes

CPT CODE 86022x2
LOINC CODE 50736-8, 77728-4