521 Serum NT-3 and NT-4 Levels are Associated with Clinical Severity in Asthmatic Children

BACKGROUND: Neuronal modulation of inflammation and airway hyperresponsiveness has been well described in asthma and neurotrophins provide the link between inflammation and neuronal dysfunction. In humans, elevated BDNF, NGF and NT-3 levels have been found in bronchoalveolar lavage fluid (BALF) following allergen provocation. Moreover, BDNF levels are significantly higher in untreated asthmatic patients in comparison to those treated with inhaled glucocorticoids and non asthmatic controls. It has also been shown that allergic inflammation increases local all 4 neurotrophins production that are important mediators of eosinophil survival in BALF. The aim of this study was to analyze if levels of neurotrophins in serum of asthmatic pediatric patients are altered in the course of disease (exacerbation and asymptomatic period) and therefore may serve as potential biomarkers for disease activity or symptoms severity. METHODS: In the study we included 98 children diagnosed with asthma. The blood was collected twice: during exacerbation and in the asymptomatic period. The serum levels of 4 neurotrophins (BDNF, NGF, NT-3, NT-4) were analyzed with use of DuoSet ELISA Development Kit (R&D). Statistical analysis was performed with Statistica v. 9.0. RESULTS: Analysis revealed no significant differences in neurotrophins levels in serum between asthmatic patients during asthma exacerbation and asymptomatic period. However, we found that serum levels of NT-3 and NT4 correlate with disease severity, being significantly lower in mild asthmatics as compared to patients with moderate and severe asthma (P < 0.01). CONCLUSIONS: Our results suggest that neurotrophins levels do not seem to correlate with the clinical symptoms activity in the course of asthma, however 2 of them (NT-3 and NT-4) correlate with disease severity.