Tryptase

TRPAS

Specimen Type: Serum

Collection Container/Type

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions: 

1. Samples should be obtained between 15 minutes and 3 hours after the event suspected of causing mast cell activation.
2. When sample is drawn, separate serum from cells within 3 hours of collection.

Samples should be obtained between 15 minutes and 3 hours after the event suspected of causing mast cell activation. When sample is drawn, separate serum from cells within 3 hours of collection.

Transport tube

Refrigerated (cold packs)

Room temperature: Unacceptable

Refrigerated: 7 days

Frozen: 30 days

Set up: Mon-Sat; Report available: 1-2 days

<11.0 mcg/L

This test may be used as a marker of mast cell activity. Tryptase is a serine protease released by mast cells constitutively (alpha-tryptase) and during activation (beta-tryptase). Serum measurement detects both forms and does not differentiate them [1]. Elevated basal tryptase levels are not uncommon and in most cases are due to hereditary alpha tryptasemia [2]. They are also seen in mastocytosis, other myeloid disorders, allergic disorders, chronic renal failure and some chronic infections [3]. Using tryptase to confirm anaphylaxis may require drawing the sample within 30 minutes - 6 hours of the suspected event and comparison with baseline levels drawn at least 24 hours after all signs and symptoms have resolved [4].

References
1. Schwartz LB. Immunol Allergy Clin N Am 2006; 26:451-463
2. Bonadonna P et al. Curr Opin Allergy Clin Immunol 2022; 22:277-282
3. Vitte J. Mol Immunol 2015; 63:18-24
4. Weiler CR et al. J All Clin Immunol 2019; 144:883-896