Oxylipin concentration shift in exhaled breath condensate (EBC) of SARS-CoV-2 infected patients

Abstract

Infection of airway epithelial cells with severe acute respiratory coronavirus 2 (SARS-CoV-2) can lead to severe respiratory tract damage and lung injury with hypoxia. It is challenging to sample the lower airways non-invasively and the capability to identify a highly representative specimen that can be collected in a non-invasive way would provide opportunities to investigate metabolomic consequences of COVID-19 disease. In the present study, we performed a targeted metabolomic approach using liquid chromatography coupled with high resolution chromatography (LC-MS) on exhaled breath condensate (EBC) collected from hospitalized COVID-19 patients (COVID+) and negative controls, both non-hospitalized and hospitalized for other reasons (COVID-). We were able to noninvasively identify and quantify inflammatory oxylipin shifts and dysregulation that may ultimately be used to monitor COVID-19 disease progression or severity and response to therapy. 
The results indicate ten targeted oxylipins with significant differences between SAR-CoV-2 infected EBC samples and negative control samples. These compounds were prostaglandins A2 and D2, LXA4, 5-HETE, 12-HETE, 15-HETE, 5-HEPE, 9-HODE, 13-oxoODE and 19(20)-EpDPA, which are associated with specific pathways (i.e. P450, COX, 15-LOX) related to inflammatory and oxidative stress processes. Moreover, all these compounds were up-regulated in the COVID+ group, meaning their concentrations were higher in subjects with SAR-CoV-2 infection. Given that many COVID symptoms are inflammatory in nature, this is interesting insight into the pathophysiology of the disease. Breath monitoring of these and other EBC metabolites presents an interesting opportunity to monitor key indicators of disease progression and severity.

Cannabinoids detected in exhaled breath condensate after cannabis use

“…EBC is collected by condensing exhaled breath components with pre-chilled metal collars, cooling material such as dry ice pellets [ 18 ], or active cooling systems [ 19 ], providing an aqueous sample that contains condensed water vapor, water-soluble volatile organic compounds, semi-volatiles, non-volatiles, and aerosols trapped by sedimentation. EBC was used historically to explore respiratory diseases like asthma [ 20 , 21 ] and recently was used to detect oxylipin levels in Covid-19 patients [ 22 ]. EBC has also been used to detect metabolites resulting from infused opioid drugs [ 23 ] and has the potential for collecting exhaled cannabinoids as well.…”