Tryptase
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Assay |
Tryptase |
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Key Words |
Mast cell tryptase |
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Specimen Collection |
Serum (brown) Post Mortum: 20mL universal using blood from a femoral source. |
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Turnaround time |
5 days This test is referred to another centre: Department of Clinical Chemistry and Immunology
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Test indications |
Tryptase is released from mast cells during anaphylaxis. It has a half-life of approximately 3 hours, and serum levels peak at approximately 2-4 hours after systemic anaphylaxis, and usually return to normal by 24 hours. Persistently elevated levels may be seen in mastocytosis and urticaria pigmentosum. Tryptase measurements are particularly helpful in patients with suspected atypical allergic reactions, and in anaphylaxis during general anaesthesia. It is reasonable to take a sample 3 and 24 hours post reaction, occasionally intermediate samples may also be helpful. Anaphylaxis samples are required at immediately post event, 1-2hrs and > 24 hours post reaction. The time should be stated on the request. This is in line with BSACI guidelines for the investigation of suspected anaphylaxis during general anaesthesia Clinical & Experimental Allergy, 40, 15–31. For mastocytosis one sample is required, if positive a second will be requested. |
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Methodology |
Enzyme immunoassay |
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Interferences |
No known methodological interferences |
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Reference Range |
2.0 – 14.0 ng/mL |
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Analytical error |
Contact referral laboratory |
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Reference change value |
N/A |
