Inherited and acquired determinants of serum tryptase levels in humans.

Abstract Objective To aid the clinician in correctly interpreting serum tryptase levels. Data Sources Primary peer-reviewed literature. Study Selections Clinical and basic science peer-reviewed studies characterizing the genetic and physiological bases for tryptase generation, secretion, and elevation, including those describing serum tryptase levels in population-based cohort studies. Results Clinically measured basal serum tryptase (BST) consists of ostensibly inactive alpha- and beta-tryptase precursors. The autosomal dominant genetic trait hereditary alpha-tryptasemia is the most often cause for elevated BST levels, with other acquired causes, such as renal failure and clonal myeloid diseases being far less common. Acute increases in serum tryptase levels resulting from release of mature tryptase from secretory granules is specific to mast cell degranulation but is not detected in all cases of systemic anaphylaxis. Conclusion Understanding the differences and distinguishing between acute increases in serum tryptase and chronic elevations in BST owing to inherited or acquired conditions is critical in the correct interpretation of this useful clinical biomarker.