Skip to contentSkip to navigation
Trypsin, Mast Cell Tryptase


Tryptase is an enzyme (protein) that is released along with histamine and other chemical substances by mast cells, the white blood cells responsible for allergic reactions. Histamine and other chemical substances are responsible for the sometimes very severe symptoms of an allergic reaction (anaphylactic shock). Results are expressed in micrograms of tryptase per litre of blood (µg/L).

Normal levels of tryptase indicate that the individual’s symptoms are probably not due to mast cell activation. Levels of tryptase typically reach their maximum level one to two hours after the onset of symptoms. The time of collection is therefore important to prevent false negative results. High levels found intermittently or acutely in an individual with anaphylaxis symptoms indicate that an allergic reaction is most likely the cause. Chronically high levels of tryptase suggest either a mast cell activation disorder or mastocytosis, a rare disease associated with an abnormal increase in the number of mast cells. They can accumulate in the skin (cutaneous mastocytosis) leading to urticaria pigmentosa, or in all organs (systemic or malignant mastocytosis, mast cell leukemia).

Term of the Week

Creatine Kinase MM (CK-MM)

CK (creatine kinase) is an enzyme (protein) found in several tissues, including muscles and the heart. Depending on the tissue, different forms of CK are present: CK-MM is primarily present in skeletal muscles, CK-MB represents 30% of CK from the heart, while CK-BB comes from the brain and smooth muscle, such as the intestinal walls. Atypical forms of CK (macro CK1 and macro CK2) can also be present. CK electrophoresis is most useful when muscular or cardiac disease does not seem to be responsible for the increased level of total CK.