Increased blood [TAME]-esterase activity during exercise-induced asthma

Area of Science:

• Pediatric Allergy and Immunology
• Respiratory Medicine
• Biochemistry

Background:

• Exercise-induced asthma (E-IA) is a common condition in children.
• The underlying mechanisms of E-IA, particularly late asthmatic responses, require further elucidation.
• N-alpha-tosyl-L-arginine methyl ester [TAME]-esterase activity has been implicated in inflammatory processes.

Purpose of the Study:

• To investigate the association between [TAME]-esterase activity and E-IA in non-atopic asthmatic children.
• To explore the relationship between [TAME]-esterase activity and late asthmatic responses following exercise.
• To assess peripheral blood eosinophil levels in relation to E-IA.

Main Methods:

• Study included twelve non-atopic asthmatic children with E-IA and eight non-asthmatic children.
• Lung function tests and clinical examinations were conducted at rest, immediately, and 4 hours post-exercise (6-minute cycling).
• Blood samples were analyzed for [TAME]-esterase activity and eosinophil counts.

Main Results:

• Asthmatic children demonstrated consistently elevated [TAME]-esterase activity immediately post-exercise.
• Peripheral blood eosinophil levels were also elevated in asthmatic children following exercise.
• A correlation was observed between E-IA and a specific threshold of [TAME]-esterase activity.

Conclusions:

• E-IA in children is associated with increased [TAME]-esterase activity.
• A simple colorimetric method can effectively measure [TAME]-esterase activity relevant to E-IA.
• These findings suggest [TAME]-esterase activity as a potential biomarker for E-IA.