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.

[Impact of a Senso-Motoric Intervention in COPD-Patients Participating in an Outpatient Pulmonary Rehabilitation Program: A Randomized Controlled Trial]

Objective Exercise training provides a cornerstone of pulmonary rehabilitation (PR) in COPD-patients. However, the components of the training are not yet fully investigated. We conducted a randomized controlled trial to investigate the effectiveness of a sensory-motoric training (SMT) in comparison to a conventional strength training (KT) according to the physical performance. Patients and Methods: 43 COPD patients were randomized and participated either in the intervention group (SMT = 30 minutes SMT per day) or in the control group (KT = 30 minutes KT per day). The SMT was performed as circuit training with five stations. The primary endpoint was the difference between T1 (start of the PR) and T2 (end of the PR) in 5-Times Sit-to-stand test (5-STST) in the intergroup comparison. Secondary endpoints were the intra- and intergroup comparisons of T1 and T2 in the 6-Minute Walk Test (6-MWT), COPD Assessment Test (CAT), St. George Respiratory Questionnaire (SGRQ), Hospital Anxiety- and Depression Scale (HADS) and in lung function. Results No significant differences were seen in the results of the 5-STST between the groups. Likewise, in the 6-MWT, SGRQ, CAT, HADS and lung function. The intragroup comparison between T1 and T2 showed significant differences in 5-STST, 6-MWT, SGRQ, CAT and HADS in both groups. The differences in lung function were not significantly, neither in the inter- nor in the intragroup comparison. Conclusion Similarly to a conventional strength training improvements in exercise capacity could be achieved with a SMT during PR in COPD patients. Further studies are necessary to define the role of the SMT in regards to postural control.

[Outcome predictors for COPD patients hospitalized for acute exacerbation]

BACKGROUND

Prognostic factors for clinical failure of acute exacerbation in patients with COPD (AECOPD) are of special importance in order to choose an adequate therapy and resources during inpatient treatment. Our database was analyzed to identify predictors for a negative outcome.

MATERIALS AND METHODS

In a retrospective analysis medical records of 616 patients (299 women; 317 men) hospitalized for AECOPD between January 2011 and January 2016 were analyzed in order to evaluate demographic and clinical parameters leading to adverse events. Only the first admission was considered. Logistic regression analysis was performed to determine the relative risk (odds ratio (OR) leading to severe adverse events such as intensive care unit (ICU) admission, mechanical ventilation (invasive or noninvasive), early readmission to ICU and hospital and death).

RESULTS

An increased risk of an ICU admission was found for patients with a coronary heart disease (OR = 5.734; p = 0.009) and for patients requiring an antibiotic therapy (OR = 11.721; p = 0.003). An increased risk for rehospitalisation and mortality was found for age (OR = 1.034; p = 0.028) and a longer duration of the hospital stay (OR = 1.063; p = 0.042). A lower C‑reactive protein (CRP) level was associated with a lower risk of readmission to the hospital (OR = 0.991; p = 0.03). An increased risk of ventilator therapy was found for patients with chronic heart failure (OR = 6.166; p = 0.02) and sleep apnea syndrome (OR = 6.698; p = 0.003), diabetes (OR = 3.754; p = 0.041) and a long stay in the ICU (OR = 2.018; p = 0.000).

CONCLUSIONS

Comorbidities in patients with AECOPD were found to be a major risk factor for ICU admission and mechanical ventilation. Elderly patients and patients with prolonged hospital stay showed a higher risk for readmission and mortality. Patients with a low CRP blood level seemed to have a lower risk for rehospitalisation.

A dual center study to compare breath volatile organic compounds from smokers and non-smokers with and without COPD

There is increasing evidence that breath volatile organic compounds (VOC) have the potential to support the diagnosis and management of inflammatory diseases such as COPD. In this study we used a novel breath sampling device to search for COPD related VOCs. We included a large number of healthy controls and patients with mild to moderate COPD, recruited subjects at two different sites and carefully controlled for smoking. 222 subjects were recruited in Hannover and Marburg, and inhaled cleaned room air before exhaling into a stainless steel reservoir under exhalation flow control. Breath samples (2.5 l) were continuously drawn onto two Tenax(®) TA adsorption tubes and analyzed in Hannover using thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Data of 134 identified VOCs from 190 subjects (52 healthy non-smokers, 52 COPD ex-smokers, 49 healthy smokers, 37 smokers with COPD) were included into the analysis. Active smokers could be clearly discriminated by higher values for combustion products and smoking related VOCs correlated with exhaled carbon monoxide (CO), indicating the validity of our data. Subjects from the study sites could be discriminated even after exclusion of cleaning related VOCs. Linear discriminant analysis correctly classified 89.4% of COPD patients in the non/ex-smoking group (cross validation (CV): 85.6%), and 82.6% of COPD patients in the actively smoking group (CV: 77.9%). We extensively characterized 134 breath VOCs and provide evidence for 14 COPD related VOCs of which 10 have not been reported before. Our results show that, for the utilization of breath VOCs for diagnosis and disease management of COPD, not only the known effects of smoking but also site specific differences need to be considered. We detected novel COPD related breath VOCs that now need to be tested in longitudinal studies for reproducibility, response to treatment and changes in disease severity.

[Cheyne-Stokes respiration in patients with chronic heart failure: only a diagnostic marker or also a cardiovascular risk factor?]

Sleep disordered breathing with predominant obstructive or central apnea is an under-recognized but highly prevalent comorbidity in patients with chronic heart failure. As the severity of heart failure increases the prevalence of central sleep apnea (CSA) and Cheyne-Stokes respiration (CSR) is also much more frequent. Cheyne-Stokes respiration is characterized by alternating periods of crescendo and decrescendo respiration followed by central apnea. Present data indicate that CSA-CSR is not only a compensatory response to severe heart failure but also a predictor of worse prognosis. However the results on long-term mortality are not consistent. The prognostic importance of night- and daytime CSR has to be further elucidated. Increased sympathetic nervous activity has been proposed to play a mayor role concerning progression and outcome of chronic heart failure by CSA-CSR.

Prospective evaluation of duodenogastroesophageal reflux in gastroesophageal reflux disease patients refractory to proton pump inhibitor therapy

BACKGROUND

Duodenogastroesophageal reflux (DGER) is considered an independent risk factor for complicated reflux disease (gastroesophageal reflux disease; GERD). However, the role of DGER in GERD patients refractory to proton pump inhibitors (PPI) remains poorly understood.

METHODS

85 patients with clinical reflux symptoms and a history of ineffective response to PPIs were enrolled in the study. Patients with elevated reflux measurement (pH and/or Bilitec measurement; n = 47) received pantoprazole 80 mg for 8 weeks. Clinical outcome was defined as response (≤2 symptoms/week) or nonresponse (≥3 symptoms/week).

RESULTS

Of the 47 patients with elevated reflux measurement, 30 were classified as responders and 17 as nonresponders. Treatment with pantoprazole resulted in a significant reduction of acidic reflux in both PPI responders and PPI nonresponders. In contrast, DGER was only significantly reduced in the PPI responder group (22.8 ± 22.8 vs. 6.6 ± 10.8%; p < 0.05) but not in the PPI nonresponder group (24.5 ± 18.6 vs. 22.2 ± 12.7%; p > 0.05).

CONCLUSIONS

The presented study firstly describes that nonresponsiveness to PPI is associated with a limited effect of PPIs on reducing DGER. Thus, persistent DGER may play a key role in mediating reflux symptoms refractory to high-dose PPIs.

[Special training therapy to reduce inflammation in Anti-Jo-1 syndrome]

A 46-year-old patient was frequently seen with a medically treated Anti-Jo-1 syndrome. The patient had already been treated with azathioprine and oral corticosteroids on account of decreasing lung function, dyspnoea, fatigue, and beginning signs of myositis. Although high doses of steroids and azathioprine were administered, the muscleskeletal syndromes increased steadily. The patient used to be an active long-distance runner (20 km), but now was unable to perform that kind of physical exercise. It was decided to start a treatment with the GalileoTM training device for active muscle training of the lower extremities. Before and after three months of training the following assessment was performed: measurement of health-related quality of life (St. Georges respiratory questionnaire, SGRQ), ultrasound measurement of the cross-sectional area of the quadriceps muscle, 6 minute walk test (6 MWT), lung function testing, and assessment of serum markers of inflammation (TNF-alpha, interleukin-8, CRP, CK, myoglobin). After only two months, training with the GalileoTM five times a week has improved the patient's conditions dramatically. The training will be continued.

Combined lung-sound and reflux-monitoring: a pilot study of a novel approach to detect nocturnal respiratory symptoms in gastro-oesophageal reflux disease

BACKGROUND

Increased prevalence of respiratory symptoms has been commonly reported in patients with gastro-oesophageal reflux disease (GERD).

AIM

To introduce a novel Lung-Sound-Monitoring device that allows simultaneous measurement of both nocturnal respiratory symptoms and episodes of acidic and biliary refluxes.

METHODS

Nocturnal respiratory symptoms (coughing and wheezing) were continuously recorded in 20 healthy subjects and 30 reflux patients with respiratory symptoms in parallel to combined pH-monitoring and Bilitec measurement.

RESULTS

Analysis could be completed in 20 healthy subjects and in 25 patients with reflux. A clear temporal correlation to reflux phases was detected in 49% of coughing and 41% of wheezing events, respectively. Moreover, 89% of the coughing and 100% of the wheezing events succeeded reflux episodes. Finally, the technique was capable of assessing a statistically significant difference between patients and controls regarding the occurrence of these symptoms.

CONCLUSIONS

Our pilot study establishes the Lung-Sound-Monitoring system as a unique tool to measure objectively the temporal correlation between gastroesophageal reflux and the appearance of respiratory symptoms. It represents a useful technique to identify patients with respiratory symptoms due to reflux, and therefore allows one to determine and quantify the impact of therapeutic interventions such as antireflux therapy on respiratory symptoms.

[Nocturnal long-term monitoring of lung sounds in patients with gastro-oesophageal reflux disease]

Gastro-oesophageal reflux disease (GERD) is one of the most common clinical conditions in the developed countries. Particular interest in pulmonary manifestations of this disease has arisen over the last few years. Although the high coincidence between reflux and chronic cough is unquestioned, the proof of a causal correlation is still lacking. In this paper we present the Marburger Lung-Sound-Monitoring as a new method for the detection of nocturnal respiratory symptoms such as cough, wheezing and throat clearing and their temporal correlation with reflux. This method will in future allow us to precisely record and to evaluate the extent and duration of reflux events and their correlation with respiratory symptoms.

Gene regulation of HBP 23 by metalloporphyrins and protoporphyrin IX in liver and hepatocyte cultures

Heme-binding protein 23 kDa (HBP23) belongs to the antioxidant family of peroxiredoxins and binds heme with high affinity. In vivo treatment of rats with heme induced expression of HBP23 mRNA levels in liver coordinately with that of the heme degrading enzyme heme oxygenase-1 (HO-1). In primary rat hepatocyte cultures Sn-, Co-, and Zn-metalloprotoporphyrin as well as the heme precursor protoporphyrin IX increased the HBP23 mRNA expression to a level similar to that elicited by heme. Heme-dependent induction of HBP23 mRNA was prevented by pretreatment with actinomycin D, indicating a transcriptional mechanism of gene induction. The results suggest that the coordinate gene regulation pattern of HBP23 and HO-1 plays a physiological role against oxidative stress.

Expression of the mRNA of heme-binding protein 23 is coordinated with that of heme oxygenase-1 by heme and heavy metals in primary rat hepatocytes and hepatoma cells

A 23-kDa protein with high affinity for heme (KD = 55 nM), therefore termed heme-binding protein 23 kDa (HBP23), was purified from rat liver cytosol [Iwahara, S., et al. (1995) Biochemistry 34, 13398-13406]. Homology search of the cloned HBP23 cDNA revealed that this protein belongs to a recently recognized class of thiol peroxidases, the antioxidant peroxiredoxin family. Since HBP23 gene expression was highest in the liver, HBP23 mRNA regulation by heme and heavy metals was investigated in cultures of primary rat hepatocytes and mouse hepatoma Hepa 1-6 cells. In both cell cultures HBP23 mRNA levels were upregulated in a time- and dose-dependent manner by heme. Heme-dependent induction of HBP23 mRNA occurred coordinately with that of the heme-metabolizing enzyme heme oxygenase-1, which was recently identified as inducible by oxidative stress. Treatment of primary rat hepatocyte or hepatoma cell cultures with the heavy metals CdCl2 (10 microM) and CoCl2 (300 microM) induced in parallel HBP23 and HO-1 mRNA levels, in the case of CdCl2 to even higher levels than heme. By contrast, mRNA expression of another heme binding protein, hemopexin, was not induced in hepatocyte cell cultures by heme or heavy metals. The data suggest that the expression of HBP23 and HO-1 mRNA is regulated by (a) similar mechanism(s) in liver and that both genes could play a common physiological role as antioxidants and/or in heme metabolism.