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Test Code LAB2225 Heparin Associated Anti-Platelet IgG Antibody with Reflex to Serotonin Release Assay (SRA)

Important Note

Specimens must be received in labortatory prior to 9AM to be resulted that day.

Additional Codes:

PF4/Reflex

Includes:

Heparin Associated Anti-Platelet Antibody (PF4 antibody) with reflex to Serotonin Release Assay (SRA). If the PF4 antibody is positive, SRA is performed at an additional charge.

For orders from MUSC and Non-MUSC providers, the SRA will automatically be sent to a reference lab when the PF4 Antibody is positive (>0.500 OD). Specimens received Monday – Friday will be sent out same day. Specimens received on Saturday and Sunday will be sent out on Monday. 

For orders from MUSC providers, a follow-up consultation from the Anticoagulation and Bleeding Management Group will be provided when the PF4 Antibody is positive (>0.500 OD).

Notes:

Do not draw from a heparinized line. Samples anticoagulated with heparin are not suitable for testing with this assay.

Include Heparin type and date/time of last dose.

Hemolyzed specimens are unacceptable.

Collection:

Specimen: Blood

Container: Two 4 ml Serum Separators or one 7 ml Plain Red Top Tube

Volume: 7 mL; Minimum 5 mL

 

Rejection Criteria: Gross helolysis, lipemia, icteric serum.

Storage Instructions:

Serum should be separated from red cells when stored or shipped. Samples that cannot be tested immediately should be stored at 2-8 o C for up to 48 hours. For storage beyond 48 hours, freeze specimen -80 o C.

Turnaround Time (TAT):

Reported same day as performed.

Test Availability:

Performed at 9 AM daily (Sun-Sat).

Assay:

2.0 mL serum

Request Form:

Routine Laboratory Request Form

Send To:

UMC MAIN LABORATORY Specimen Receiving – EH319 Extension Hospital

Reference Interval:

Interpretation Range
Negative <0.400 OD
Borderline 0.400 - 0.500 OD
Positive >0.500 OD

Interpretive Data:

Negative (<0.400 OD)

Borderline (0.400 - 0.500 OD) - Repeat in 24-48 hours if clinically indicated

Equivocal (>0.500 OD and <50% inhibition) - Specimen will not be sent to a reference lab for confirmation. Results show reactivity in the presence of heparin, however there is no inhibition of reactivity when excess heparin is added. These results do not support a diagnosis of HIT-related antibody but can be seen in the presence of either HLA or platelet-specific autoantibodies.

Positive (>0.500 OD and >50% inhibition) - Specimen will be sent to a reference lab for confirmatory testing at an additional charge.