Respiratory metabolites in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) can differentiate horses affected by severe equine asthma from healthy horses

Marilena Bazzano,Beniamino Tesei,Chenglin Zhu,Gian Enrico Magi,Fulvio Laus,Luca Laghi

doi:10.1186/s12917-020-02446-9

Marilena Bazzano, Beniamino Tesei + Show 4 more

Open Access

https://doi.org/10.1186/s12917-020-02446-9

Copy DOI

Abstract

BackgroundThe use of an untargeted metabolomic approach to investigate biofluids of respiratory origin is of increasing interest in human and veterinary lung research. Considering the high incidence of equine asthma (> 14%) within horse population and the importance of this animal model for human disease, we aimed to investigate the metabolomic profile of bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) in healthy and asthmatic horses.ResultsOn the basis of clinical, endoscopic and BALF cytology findings, 6 horses with severe asthma (Group A) and 6 healthy horses (Group C) were included in the study. 1H-NMR analysis was used to identified metabolites in BALF and EBC samples. Metabolomic analysis allowed to identify and quantify 12 metabolites in BALF and seven metabolites in EBC. Among respiratory metabolites, myo-inositol, formate, glycerol and isopropanol in BALF, and methanol and ethanol in EBC, differed between groups (p < 0.05).ConclusionsThe application of metabolomic studies to investigate equine asthma using minimally invasive diagnostic methods, such as EBC metabolomics, provided promising results. According to our research, the study of selective profiles of BALF and EBC metabolites might be useful for identifying molecules like myo-inositol and methanol as possible biomarkers for airways diseases in horses.

Highlights

The use of an untargeted metabolomic approach to investigate biofluids of respiratory origin is of increasing interest in human and veterinary lung research
In the current study we aimed to evaluate the respiratory metabolites in bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) of healthy horses and horses affected by severe equine asthma
Endoscopic evaluation of airways during BALF collection revealed the presence of tracheal mucus [22] and thickening of tracheal septum in horses from group A, whereas normal airways aspect was found in control group

Summary

Introduction

The use of an untargeted metabolomic approach to investigate biofluids of respiratory origin is of increasing interest in human and veterinary lung research. Considering the high incidence of equine asthma (> 14%) within horse population and the importance of this animal model for human disease, we aimed to investigate the metabolomic profile of bronchoalveolar lavage fluid (BALF) and exhaled breath condensate (EBC) in healthy and asthmatic horses. Despite the fact that the respiratory cytological reaction is predominantly eosinophilic in men and neutrophilic in horses, equine asthma is a recognized model for human disease [14, 15]. In horses showing respiratory symptoms compatible with asthma, the diagnosis is currently based on the presence of abnormal bronchoalveolar lavage fluid (BALF) cytology [19], but molecular biomarkers of lung inflammation would offer new insight for pathogenetic and diagnostic advances. Previous studies investigated biomarkers of oxidative stress [21], hydrogen peroxide content and pH variations in EBC of horses [20], and only one study performed the metabolomic analysis of equine EBC [11]

Objectives

Methods

Results

Conclusion