Mast Cell Tryptase (MCT)

Department of Immunology

Notes

• Mast Cell Tryptase (MCT) is a marker of mast cell degranulation. MCT measurement is of value in the assessment of anaphylactic reactions.
• Ideally three samples are required:
  • First sample: ASAP (ideally within 30 minutes of the reaction).
  • Second sample: 1-2 hours post reaction.
  • Third sample: 24 hours post reaction.
• Please state clearly on the request form the timing of the sample in relation to the reaction.
• If there are any abnormal findings, then the patient should be referred to Clinical Immunology. In the event of an anaesthetic drug reaction a referral by the Anaesthetist will need to be sent to Allergy in Bristol.
• MCT is also be used for the investigation chronic mast cell disorders, including systemic mastocytosis.
• Test performed at Southmead Hospital, Bristol.

Sample Requirements

Clotted blood. (No patient preparation or special handling required).

See information regarding sample timings in the Notes section above.

Adult

5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)

Paediatric

1ml Serum Sample

Time Limit for Add-ons

3 days

Turnaround Times

2 weeks

Reference Ranges

1 – 15 µg/l