Serum tryptase levels and correlation with severity of anaphylaxis in allergic patients

• Grant number: 16/10642-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2016
• End date: August 31, 2017
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Luisa Karla de Paula Arruda
• Grantee: Vinícius Aniceto
• Host Institution: Faculdade de Medicina de Ribeirão Preto (FMRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Anaphylaxis is a severe, potentially fatal, allergic reaction, which generally occurs after exposure to a trigger. This clinical condition is more common than most people realize, and there is evidence that anaphylaxis is underdiagnosed and undertreated. Most common triggers include foods, drugs and venom of Hymenoptera insects (wasps, bees and ants), with variable prevalence, depending of the patient's age and geographical location. One of the main events in the pathogenesis anaphylaxis is the degranulation of mast cells, leading to release of many substances such as tryptase, an enzyme which can be measured in peripheral blood. The increase of tryptase concentration is a very specific marker of mast cells' activation. Moderately high serum levels of tryptase (over than 11.4 ng/mL) are related to greater risk of anaphylaxis, and, if it occurs, to a greater risk of more serious anaphylaxis (grades III and IV). Besides, very high serum levels of tryptase (over than 20.0 ng/mL) may indicate presence of mastocytosis, warranting further investigation to diagnose this medical condition.In the present study, we intend to measure serum levels of tryptase in patients attending the Allergy and Immunology Clinics of HCFMRP-USP who have already had at least one episode of anaphylaxis, and characterize their clinical condition, as well their signs and symptoms, and the treatment they received at their first episode of anaphylaxis. Correlations of serum levels of tryptase and severity of anaphylaxis, as well as other demographical and clinical parameters including the type of triggering factors will be carried out in these patients.