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Serum or plasma mass concentration of mast cell tryptase

Published: August 9, 2026Updated: August 17, 2026

This test measures the amount of tryptase, a protein released by mast cells, which are immune cells involved in allergic reactions and inflammation.

Quick summary

["Helps diagnose conditions linked to mast cell activation, such as anaphylaxis or mast cell disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
36839-9
Short code
XR Mastoid 4V
Synonyms
XR Mastoid 4V
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Ref low
10
Ref high
40
Critical range
— – 500 N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
xr
CPT
84484
SNOMED
302774002
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What Is Mast Cell Tryptase Used For?

Mast cell tryptase is primarily used to identify and monitor conditions where mast cells release excessive amounts of tryptase, such as severe allergic reactions (anaphylaxis) or rare disorders like mastocytosis. It can also help assess the effectiveness of treatment in these conditions.

How Is the Test Performed?

A blood sample is drawn from a vein, typically in the arm. The sample is then processed to separate serum or plasma, where tryptase levels are measured using a specialized laboratory technique.

What Does a High or Low Level Mean?

Elevated tryptase levels may indicate recent or ongoing mast cell activation, which can occur in allergic reactions, anaphylaxis, or certain blood disorders. Low levels generally suggest normal mast cell function or absence of significant activation.

Common Conditions Monitored

This test is often used to diagnose or evaluate conditions such as hereditary angioedema, mastocytosis, or severe allergic reactions. It may also be part of a broader assessment for unexplained symptoms like chronic urticaria or gastrointestinal issues linked to mast cell dysfunction.

Reference range

Adult: 10-40 U/LN/A

Specimen: serum

No special preparation required. Avoid fatty meals before the test if possible.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Mast Cell Tryptase

Frequently asked questions

Why might my doctor order this test?
Your doctor may recommend this test if you have symptoms like severe allergic reactions, unexplained skin rashes, digestive issues, or if you have a suspected mast cell disorder. It’s also used in research or specialized care for conditions like hereditary angioedema or mastocytosis.
What should I expect during or after the test?
You’ll typically have a small needle inserted to draw blood, which may cause a brief pinch or discomfort. Afterward, you can resume normal activities, though you may experience mild bruising or soreness at the site. Results are usually ready within a few days to a week, depending on lab processing times.
Can lifestyle changes affect tryptase levels?
While lifestyle factors like diet, stress, or certain medications can influence overall health, they do not directly alter tryptase levels in the same way other biomarkers do. However, managing conditions like allergies or mastocytosis with prescribed treatments may help stabilize tryptase levels over time.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy