Heparin Induced Thrombocytopenia

Label Mnemonic:	HIT
Epic code:	LAB1088
Order form:	Laboratory Requisition
Supply order:	Supply Order Form
Billing:	Billing Policies
CPT code:	86022

Specimen(s):

Serum

Collection Medium:

Red top tube 5 mL (Clot Activator)

Minimum:

1 mL serum

Testing Schedule:

HIT testing is performed daily (holidays and weekends included) at 1200. Sample must be in the lab at that time to be included in the run for that day.

Reference Range:

Negative

Critical value: Positive

Comments:

For pediatric patients <18 years of age, a Pediatric Hematology/Oncology Service Consult is required for testing approval.

It is highly recommended to use the 4T calculator to estimate risk of heparin-induced thrombocytopenia (HIT). Ordering of HIT testing is highly discouraged when the 4T score is 0-3.

Please refer to the Guidelines for Recognition and Management of Heparin Induced Thrombocytopenia which also provides the 4T scoring system.

Methodology:

Enzyme Linked Immunosorbent Assay (ELISA) used to detect antibodies to Platelet Factor 4

Sample Processing:

Centrifuge at a speed and time necessary to get barrier separation of plasma/serum and cells.
Separate serum/plasma into plastic container and cap (glass is not acceptable).
Label transport tube with two patient identifiers, date and time of collection.

Sample Storage:

Freeze specimen immediately.

Transport Instructions:

Place labeled specimen into zip-lock type biohazard bag; seal bag.
Place requisition into outside pocket of bag.
Place dry ice on top of specimen in Styrofoam container to maintain frozen temperature.