Tryptase (EC3.4.21.59) is the most abundant secretory granule-derivedserine proteinase contained inmast cells and has been used as a marker for mast cell activation.[1][2][3][4][5]Club cells contain tryptase, which is believed to be responsible for cleaving thehemagglutinin surface protein ofinfluenza A virus, thereby activating it and causing the symptoms of flu.[6]
Tryptase is also known by mast cell tryptase, mast cell protease II, skin tryptase, lung tryptase, pituitary tryptase, mast cell neutral proteinase, mast cell serine proteinase II, mast cell proteinase II, mast cell serine proteinase tryptase, rat mast cell protease II, and tryptase M.
Serum levels are normally less than 11.5 ng/mL.[7] Elevated levels of serum tryptase occur in bothanaphylactic and anaphylactoid reactions, but a negative test does not excludeanaphylaxis. Tryptase is less likely to be elevated in food allergy reactions as opposed to other causes of anaphylaxis. Serum tryptase levels are also elevated in and used as one indication suggesting the presence ofeosinophilic leukemias due to genetic mutations resulting in the formation ofFIP1L1-PDGFRA fusion genes or the presence ofsystemic mastocytosis.[8][9]
^Kido H, Fukusen N, Katunuma N (June 1985). "Chymotrypsin- and trypsin-type serine proteases in rat mast cells: properties and functions".Archives of Biochemistry and Biophysics.239 (2):436–43.doi:10.1016/0003-9861(85)90709-X.PMID3890754.
^Harvima IT, Schechter NM, Harvima RJ, Fräki JE (November 1988). "Human skin tryptase: purification, partial characterization and comparison with human lung tryptase".Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology.957 (1):71–80.doi:10.1016/0167-4838(88)90158-6.PMID3140898.
