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Tryptase

Mast Cell Tryptase

Test Codes

EPIC: LAB6171, Beaker: XTRYP, Warde: TRYP

Department

Send Outs

Specimen Collection Criteria

Collect (preferred specimen): One Gold-top SST tube.
Also acceptable: One plain Red-top tube.

Physician Office/Draw Specimen Preparation

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Preparation for Courier Transport

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Rejection Criteria

Specimens not collected and processed as indicated.

In-Lab Processing

Let specimen clot 30-60 minutes then centrifuge to separate serum from cells. Transfer serum to a plastic transport tube and refrigerate (2-8°C or 36-46°F).

Transport: 1.0 mL serum, refrigerated (2-8°C or 36-46°F). (Minimum: 0.5 mL)

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): Unacceptable
Refrigerated (2-8°C or 36-46°F): 7 days
Frozen (-20°C/-4°F or below): 14 days

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Warde Medical Laboratories, Ann Arbor, MI.

Performed

Monday – Friday.
Results available in 1-3 days.

Reference Range

Less than 11 ng/L.

Test Methodology

Fluorescent Enzyme Immunoassay.

Interpretation

NORMAL LEVELS OF TRYPTASE DO NOT RULE OUT THE CLINICAL DIAGNOSIS OF ANAPHYLAXIS.

Tryptase values usually peak in the serum 30-60 minutes after an immediate hypersensitivity reaction (acute anaphylaxis) and decay with a half-life of 2 hours. Mast cell degranulation from localized allergic reactions do not result in significant serum levels of this enzyme.

This assay measures total Tryptase and does not distinguish between the alpha and beta protein types.

Samples should preferably be collected between 15 minutes and three hours after the suspected event causing mast cell activation.

Clinical Utility

This assay aids in the diagnosis of anaphylaxis, systemic mastocytosis and mast cell activation syndrome. Tryptase remains elevated in the blood for several hours following an anaphylactic reaction. The finding of an elevated tryptase which subsequently decays to background levels is evidence that the patient had experienced a systemic mast cell event. However, it should be noted that ß-tryptase levels may sometimes be elevated in postmortem sera in the absence of documented anaphylaxis. This assay also aids in the diagnosis of mastocytosis since this assay measures both forms of tryptase. Patients with mastocytosis have greatly elevated values (e.g., 30-700 ng/mL). This assay may be used to monitor allergen challenges. It has applications in various research projects where mast cell activity needs to be measured.

CPT Codes

83520
LOINC:  21582-2

Contacts

Last Updated

4/4/2023