Tryptase [TPSAB1/1961]

Tryptases comprise a family of trypsin-like serine proteases, the peptidase family S1. Tryptases are stored in mast cell secretory granules and basophils. These enzymes are released into the extracellular environment, and are resistant to all known endogenous proteinase inhibitors. Several tryptase genes are clustered on chromosome 16p13.3. There are two separate genes: alpha and beta 1. Beta tryptases appear to be the main isoenzymes expressed in mast cells whereas in basophils, alpha tryptases predominate. Tryptases have been implicated as mediators in the pathogenesis of asthma and other allergic and inflammatory disorders. Anti-tryptase is a good marker for mast cells, basophils, and their derivatives. Mastocytosis is a term collectively used for a group of disorders in which there is abnormal accumulation of mast cells in one or multiple organs. Anti-tryptase, combined with anti-CD2, anti-CD25, and anti-CD117, can be useful in the differential diagnosis of reactive mast cell hyperplasia, myelogenous neoplasms, mast cell leukemia, and mastocytosis.