Serum tryptase
Immunology and Allergy Overview / Directory
Purpose of the test
Elevated concentrations of serum tryptase are found in patients with mastocytosis and those who have recently undergone anaphylaxis. The assay measures both alpha and beta subunits of tryptase. The investigation of suspected anaphylaxis requires that 3 blood samples are taken;
- As soon as possible after onset of anaphylaxis, within one hour
- Between 3 and 6 hours post onset
- At least 24 hours after onset
This timescale allows the differentiation of true anaphylaxis and mastocytosis. In anaphylaxis the tryptase concentration will return to baseline post 24 hours whereas in mastocytosis the concentrations remain high.
Sample Requirements
See above for suspected anaphylaxis. 2 ml of freshly separated serum.
Storage and Transport
Serum stored at 4°C should be sent by first class post as soon as possible.
Turnaround Time
10 working days
Time Limit for Extra Tests
10 working days
Factors affecting results or interpretation
All tests are compromised by long transit times. For this reason the date of bleed and of postage must be provided with each request. This is an absolute requirement in the case of suspected anaphylaxis.
Price
Price available on application - please contact adrianturner1@nhs.net. Discounts could be available for significant workloads.
Contacts
John Cazabon or Rosemary Ebling, Lead Biomedical Scientists
T 020 3299 1559
Dr Ted Davies, Consultant Clinical Scientist
T 020 3299 9000 Ex 8752
Rosy Ebling, Lead BMS
T 020 3299 1559
