Mast cell tryptase, serum/plasma (24-hour profile)

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like severe allergic reactions (e.g., anaphylaxis), chronic hives, gastrointestinal issues, or unexplained skin rashes. It may also be used to monitor mastocytosis, a rare blood disorder where too many mast cells are present, or to evaluate mast cell-related conditions like mast cell activation syndrome (MCAS).

What to Expect Before the Test

No special preparation is needed. You may have blood drawn from a vein in your arm, similar to other blood tests. If you’re taking medications that could affect tryptase levels (like certain antihistamines or mast cell stabilizers), let your provider know. Avoid strenuous activity or excessive stress before the test, as these may influence results temporarily.

What the Test Results Mean

Tryptase levels in this profile can show baseline activity and spikes that occur over 24 hours. Elevated baseline levels may indicate chronic mast cell activation, while spikes could suggest acute triggers like allergens, infections, or medications. Your results will be interpreted by a healthcare provider based on your symptoms and medical history.

Common Conditions Monitored

This test is particularly useful for diagnosing or managing mastocytosis, MCAS, or other conditions where mast cells release excessive tryptase. It helps track disease progression or response to treatment by measuring changes in tryptase levels over time.