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Test Code SRAU Serotonin Release Assay, Unfractionated Heparin, Mass Spectrometry, Serum

Additional Codes

CNE Order Code = SRA


Shipping Instructions


Specimen should be frozen if shipped or stored for longer than 48 hours.



Specimen Required


Patient Preparation:

1. Specimen should be collected from a fasting (preferred, but not required) patient during an episode of suspected heparin-induced thrombocytopenia.

2. Patient should not be on ticagrelor (Brilinta) as this may interfere with the assay, yielding a false-negative result.

Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube: Red top (serum gel/SST are not acceptable)

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. After collection, specimen should sit at ambient temperature for a minimum of 1 hour in order to clot completely.

2. Centrifuge and aliquot serum into a plastic vial.

Specimen Stability Information: Frozen (preferred) 2 years/Refrigerate 7 days


Useful For

Detecting heparin-dependent platelet activating antibodies implicated in the pathogenesis of heparin-induced thrombocytopenia

Method Name

Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Serotonin Release Assay, UFH, MS, S

Specimen Type

Serum Red

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Frozen (preferred)
  Refrigerated  7 days

Reject Due To

Gross lipemia Reject

Reference Values

Low Heparin Serotonin Release: <20%

High Heparin Serotonin Release: <20%

Serotonin Release Assay Result: Negative

Interpretation

In a negative serotonin release assay (SRA), patient serum induced serotonin release of below 20% from normal donor platelets in presence of low concentration of unfractionated heparin (UFH) (0.1U/mL) regardless of the serotonin release with high concentration of UFH (100 U/mL).

 

In a positive SRA, patient serum induced serotonin release of 20% or more from normal donor platelets in presence of low concentration of UFH (0.1U/mL). This release is inhibited in presence of high concentration of UFH (100 U/mL) and falls below 20%.

 

In an indeterminate SRA, patient serum induced serotonin release of 20% or more from normal donor platelets in presence of low concentration of UFH (0.1U/mL) and high concentration of UFH (100 U/mL). Indeterminate results can occur due to non-heparin dependent antibodies (eg, human leukocyte antigen antibodies). Occasionally some indeterminate results may show greater than 50% inhibition of serotonin release from normal donor platelets in presence of high concentration of UFH (100 U/mL) compared to low concentration of UFH (0.1U/mL), which is suggestive for heparin-induced thrombocytopenia in the right clinical context.

 

Table. Results and Interpretation

Low heparin release %

High heparin release %

Interpretation

<20%

<20%

Negative

<20%

≥20%

Negative

≥20%

<20%

Positive

Day(s) Performed

Monday through Friday

Report Available

1 to 3 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
SRAU Serotonin Release Assay, UFH, MS, S 50736-8

 

Result ID Test Result Name Result LOINC Value
616230 Low Heparin Serotonin Release 50728-5
616231 High Heparin Serotonin Release 50727-7
616232 Serotonin Release Assay Result 66488-8
616233 Interpretation 50733-5
616234 Comment 77202-0
616235 Disclaimer 62364-5

Forms

If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.