Tryptase (serum) | Laboratory research

General Information

Tryptase is an enzyme produced in mast cells, which are part of the immune system. It plays an important role in the development of the immune response. Determination of serum tryptase is important in the diagnostics of pathologies such as: anaphylaxis (severe allergic reaction), mastocytosis (excessive production of mast cells), and other disorders of mast cell activity.

Tryptase is released from activated mast cells along with histamine and other vasoactive mediators.

The α and β forms of tryptase are encoded by different genes. α tryptase is secreted into the blood mainly from mast cells and its level correlates with the number of mast cells.

Serum β-tryptase levels are an indicator of mast cell activity. Thus, α-tryptase levels are elevated primarily in systemic mastocytosis (increased mast cell count), while β-tryptase levels are elevated in anaphylaxis.

Anaphylaxis is a severe, potentially fatal reaction that affects multiple organs. Allergic anaphylaxis includes IgE-mediated reactions, while anaphylaxis following tissue transplantation or blood transfusion is associated with cytotoxic reactions.

Non-allergic anaphylactic reactions may develop:

• Direct release of mediators from mast cells and basophils (physical factors, or opiate-induced reactions)
• By activating contact systems (during dialysis)
• Disorders of arachidonic acid metabolism (reactions caused by aspirin or other nonsteroidal anti-inflammatory drugs)

The clinical picture is dominated by respiratory manifestations (breathing disorders, tachypnea, bronchospasm, pulmonary edema) and cardiovascular events (tachycardia, hypotension, arrhythmias, heart failure, angina), which are supplemented by digestive system manifestations (nausea-vomiting, abdominal pain, diarrhea) and skin manifestations (tissue edema, urticaria, itching).

Anaphylactic reactions result in degranulation of mast cells and basophils and release of mediators. The released tryptase activates the kallikrein system, the complement cascade, and fibrinogen degradation.

The symptoms of systemic mastocytosis are caused by the release of mediators from mast cells, the infiltration of organs and tissues with basophils and mast cells, and the resulting complications.

Mastocytosis is characterized by itching, nasal congestion, nausea, vomiting, diarrhea, abdominal pain, and vascular instability. The above-mentioned develops due to infiltration of tissues with mast cells and basophils in the skin, digestive tract, bone marrow, liver, lymphatic system, and others.

The test measures the total tryptase level (α and β together).

When is the survey conducted?

• Confirmation of anaphylactic reactions
• Confirmation of a positive allergen test in patients with urticaria
• Diagnosis of systemic mastocytosis

Patient preparation –  it is not necessary

Research material  – Venous blood

A normal tryptase level does not exclude the presence of anaphylaxis. In patients with cutaneous mastocytosis, tryptase elevation may not occur.