Specific molecular peak analysis by ion mobility spectrometry of volatile organic compounds in urine of COVID-19 patients: A novel diagnostic approach

INTRODUCTION

SARS-CoV-2 is usually diagnosed from naso-/oropharyngeal swabs which are uncomfortable and prone to false results. This study investigated a novel diagnostic approach to Covid-19 measuring volatile organic compounds (VOC) from patients' urine.

METHODS

Between June 2020 and February 2021, 84 patients with positive RT-PCR for SARS-CoV-2 were recruited as well as 54 symptomatic individuals with negative RT-PCR. Midstream urine samples were obtained for VOC analysis using ion mobility spectrometry (IMS) which detects individual molecular components of a gas sample based on their size, configuration, and charge after ionization.

RESULTS

Peak analysis of the 84 Covid and 54 control samples showed good group separation. In total, 37 individual specific peaks were identified, 5 of which (P134, 198, 135, 75, 136) accounted for significant differences between groups, resulting in sensitivities of 89-94% and specificities of 82-94%. A decision tree was generated from the relevant peaks, leading to a combined sensitivity and specificity of 98% each.

DISCUSSION

VOC-based diagnosis can establish a reliable separation between urine samples of Covid-19 patients and negative controls. Molecular peaks which apparently are disease-specific were identified. IMS is an additional non-invasive and cheap device for the diagnosis of this ongoing endemic infection. Further studies are needed to validate sensitivity and specificity.

[Asthma Control in Adults and Children Must be Improved!]

Medication management of asthma is based on level of asthma control. GINA defined criteria for asthma control include asking about daytime symptoms, limitation of activity, nocturnal symptoms/awakenings and need for reliever treatment. Effective asthma control is necessary for preventing exacerbations and worsening of lung function. Standardized and validated questionnaires such as asthma control test (ACT) help to assess the level of asthma control. Asthma control is classified as controlled, partially controlled or uncontrolled. Multicenter studies like REALISE and AIRE give health care professionals information about effectiveness and adherence to medication over nearly 15 years. Asthma is still poorly controlled in more than 50 % of patients despite the availability of very effective drugs. Low adherence to the treatment, fear of systemic side effects related to long term treatment with inhaled corticosteroids, inadequate knowledge of the disease may be responsible factors for bad asthma control. Optimized tools for disease management and intensified education are necessary for therapeutic success.