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.

[Multifocal Pulmonary Neuroendocrine Tumours: Genesis, Diagnostics and Treatment]

Multifocal neuroendocrine lung tumour is a rare diagnosis. Multiple lung foci of different sizes are usually apparent on chest CT scans. It is assumed that multifocal neuroendocrine lung tumours originally develop from diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH). This results in cell aggregations formed by proliferation of neuroendocrine cells that are already physiologically present in the bronchial system. If these cell proliferations break through the bronchial basement membrane, they are considered to constitute tumourlets if they measure ≤ 5 mm and carcinoid tumours if they are larger than 5 mm. The speed of proliferation of the cell hyperplasias appears to vary. Many of the patients are completely asymptomatic, the multifocal neuroendocrine lung tumours being diagnosed by chance. However, other patients complain of breathlessness, reduced physical capacity and cough. There may also be reduction of lung function. In these cases, chest HRCT often reveals peribronchial fibrosis or bronchiectasis in addition to the lung foci. Bronchoscopy is usually not helpful. Surgical lung biopsy is considered to be the diagnostic gold standard. Histological examination typically shows a mixture of cell hyperplasias, tumourlets and carcinoid tumours. There is no consensus on the treatment of multifocal neuroendocrine tumours. Taking the clinical situation and the chest HRCT findings as our starting point, we developed a stepwise approach that is guided by the success of the individual therapeutic procedures. The most favourable prognosis is found in affected people without clinical symptoms whose lung foci all measure less than 5 mm. In these cases the 5-year survival rate is over 90%.

Abstract P6-08-06: Sexual function, sexual activity and quality of life in women with breast cancer

Background: Breast cancer (BC) is generally assumed to have an impact on sexual function and activity. Although there are several studies addressing the issue, case control studies are currently limited.

Methods: We performed a cross-sectional investigation of sexual function and activity utilizing the sexual activity questionnaire, the female sexual function index, and parts of the EORTC QLQ C30. Patients with breast cancer (BC) were compared with a control group (C) of non-cancer patients. Inclusion of BC was only allowed if treatment was completed ≥ 12 months previously and patients were disease-free. This study was approved by the ethical committee of the Landesärztekammer Hessen. All consecutive patients with breast cancer who were treated at our hospital were prospectively documented in a clinical tumor registry since 2001. All patients’ records are updated annually. The control sample without any oncologic disease of 392 age-matched females was recruited in the Department of Prosthodontics, University Hospital Mainz.

Results: Between December 2009 and May 2010 the questionnaires were sent out to 790 women (398 x BC and 392 x C), 21.6% of which responded. Response rates in both groups were equivalent (84 patients with BC [21.2%] and 87 control subjects [22.2%]). Median age was 57 years (C) and 62 years (BC), respectively (p = 0.005). 51.5% (C) and 60% (BC) were not sexually active, mainly owing to lack of a partner (39%) or lack of interest (21%) in controls and lack of interest (48%, p<0.05), self-reported physical problems (34%, p<0.05), and physical problems of the partner (22%, p<0.05) in breast cancer patients. There were significant differences between both groups in the SAQ discomfort score (p<0.05). We did not observe significant differences in quality of life or other scores regarding sexuality.

Conclusions: About half of the women in both groups were not sexually active. However, reasons for non-activity differ. Quality of sexuality tends to be impaired in BC patients, but this seems not to influence quality of life. A shift of priority caused by substantial anxiety regarding cancer specific survival might explain our findings.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-08-06.

Novel inhibitors of Erm methyltransferases from NMR and parallel synthesis

The Erm family of methyltransferases confers resistance to the macrolide-lincosamide-streptogramin type B (MLS) antibiotics through the methylation of 23S ribosomal RNA. Upon the methylation of RNA, the MLS antibiotics lose their ability to bind to the ribosome and exhibit their antibiotic activity. Using an NMR-based screen, we identified a series of triazine-containing compounds that bind weakly to ErmAM. These initial lead compounds were optimized by the parallel synthesis of a large number of analogues, resulting in compounds which inhibit the Erm-mediated methylation of rRNA in the low micromolar range. NMR and X-ray structures of enzyme/inhibitor complexes reveal that the inhibitors bind to the S-adenosylmethionine binding site on the Erm protein. These compounds represent novel methyltransferase inhibitors that serve as new leads for the reversal of Erm-mediated MLS antibiotic resistance.