Referred to Berkshire & Surrey Pathology Services, Frimley Park Hospital Frimley Park Hospital NHS Foundation Trust, Portsmouth Road, Frimley, Surrey GU16 7UJ

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Samples required

Clotted blood (gold cap, 5 mL tube). Smaller tubes are available for paediatric samples.

3 samples requested in suspected anaphylaxis:

1. as soon as possible after first symptoms

2. 1 to 2 hours after onset of symptoms. Samples taken more than 4h post event will be unhelpful due to short half life of tryptase.

3. 24h post onset of symptoms.

Samples and request forms must be clearly labelled with dates and times. Clinical information regarding onset of symptoms is essential for interpretation.

Test indications

Evaluation of mastocytosis or suspected anaphylaxis.

Reference range

0.0 - 11.0 µg/L

Tryptase is chronically raised in mastocytosis. In anaphylaxis, tryptase will be increased during the reaction, then return to baseline.

Turnaround time

Referral lab quotes turnaround time of 6 days, however additional time must be allowed for packing, dispatch and delivery of sample, and return and processing of results.


Immunology (Referrals)