Tryptase Blood Test

This test measures the tryptase levels in the blood to diagnose the cause of anaphylaxis, mast cell activation, or mastocytosis. In addition, this test helps monitor patients with diagnosed mast cell disorders to see whether their condition is stable or worsening.

Tryptase is an enzyme found in activated mast cells, along with histamine and other chemicals, often as part of an allergic reaction. Mast cells are tissue cells found throughout the body, specifically in the skin, the lining of the intestines, and air pathways. Mast cells are essential to the immune system's response to antigens and allergens. When these antigens and allergens come in contact with the skin, intestines, or air pathways, they activate the mast cells, prompting them to release chemicals such as tryptase and histamine. These chemicals trigger the symptoms related to an allergic reaction, and elevated tryptase levels may cause a severe allergic reaction, also known as anaphylaxis.

Usually, there are low traces of tryptase in the blood. However, activated mast cells cause a rapid increase in tryptase levels within a few minutes to a few hours. Allergy symptoms may range from mild to moderate. However, for individuals suffering from anaphylaxis, the symptoms may be life-threatening. Common symptoms of anaphylaxis may include:

• Abdominal pain
• Anxiety
• Chest tightness
• Difficulty breathing
• Difficulty swallowing
• Lightheadedness or dizziness
• Loss of consciousness
• Low blood pressure
• Narrowing of air pathways
• Nausea and vomiting
• Skin redness, itching, or hives
• Swelling of the face or tongue

In some cases, mast cells may become activated without apparent allergies or other reasons. An individual may have a mast cell disorder that causes abnormally high levels of tryptase in their blood. Mast cell disorders are rare conditions characterized by the overgrowth of mast cells in the skin (cutaneous mastocytosis) and organ tissues throughout the body (systemic mastocytosis).

Individuals may order this test if they have experienced symptoms of anaphylaxis or to diagnose or monitor a mast cell disorder. Contact your doctor or healthcare provider if you have significant concerns or questions about your recent lab results.