Mast cell tryptase changes within Unity

February 2, 2024

When a mast cell tryptase is requested electronically there will be a new question on the order form where the user has to answer ‘time taken after start of symptoms?’ from a selection of answers:

• <1 hour
• 1 – 3 hours
• 3 – 6 hours
• 6 – 12 hours
• 12 – 24 hours
• >24 hours/baseline
• Not available

This information will also be available on Unity along with the result.

If a tryptase is requested manually the time the sample was taken after the start of the symptoms should also been included on the request form.

Clinical guidance: In case of anaphylaxis, tryptase will raise with peak level around one hour, returning to baseline in about 6 – 8 hours. Accurate time of sample collection and time of onset of reaction is required to assess for anaphylaxis. Sample should be taken as soon as possible after reaction; Second sample between 1 – 2 hours and third sample 24 hours or later would be ideal. As a minimum, one sample around 1 hour should be obtained to assess for anaphylaxis.

For more information, please call Immunology laboratory on 01902 695279 or email rwh-tr.ImmunologyLab@nhs.net.