Alpha-Tryptase Overexpression as a Modifier of Mast Cell-Mediated Reactions

In the decade since its first description, our understanding of hereditary alpha-tryptasemia (HαT) and its clinical impact on the field of allergy has continued to evolve. We now know that HαT is a common genetic trait that impacts the frequency and/or severity of systemic mast cell-mediated reactions. Moreover, as a natural overexpression model of α-tryptase, HαT brought our attention to the importance of tryptase isoform composition in health and disease, the implications of which we are still working to fully understand. In this review, we will summarize the data examining the importance of HαT and α-tryptase more generally on the prevalence and severity of anaphylaxis in patients with venom allergy, drug allergy, food allergy, clonal mast cell disease, and idiopathic anaphylaxis.