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.

Alpha1-antitrypsin deficiency in Greece: Focus on rare variants

PURPOSE

A1Antitrypsin deficiency (AATD) pathogenic mutations are expanding beyond the PI*Z and PI*S to a multitude of rare variants.

AIM

to investigate genotype and clinical profile of Greeks with AATD.

METHODS

Symptomatic adult-patients with early-emphysema defined by fixed airway obstruction and computerized-tomography scan and lower than normal serum AAT levels were enrolled from reference centers all over Greece. Samples were analyzed in the AAT Laboratory, University of Marburg-Germany.

RESULTS

Included are 45 adults, 38 homozygous or compound heterozygous for pathogenic variants and 7 heterozygous. Homozygous were 57.9% male, 65.8% ever-smokers, median (IQR) age 49.0(42.5-58.5) years, AAT-levels 0.20(0.08-0.26) g/L, FEV1(%predicted) 41.5(28.8-64.5). PI*Z, PI*Q0, and rare deficient allele's frequency was 51.3%, 32.9%,15.8%, respectively. PI*ZZ genotype was 36.8%, PI*Q0Q0 21.1%, PI*MdeficientMdeficient 7.9%, PI*ZQ0 18.4%, PI*Q0Mdeficient 5.3% and PI*Zrare-deficient 10.5%. Genotyping by Luminex detected: p.(Pro393Leu) associated with MHeerlen (M1Ala/M1Val); p.(Leu65Pro) with MProcida; p.(Lys241Ter) with Q0Bellingham; p.(Leu377Phefs*24) with Q0Mattawa (M1Val) and Q0Ourem (M3); p.(Phe76del) with MMalton (M2), MPalermo (M1Val), MNichinan (V) and Q0LaPalma (S); p.(Asp280Val) with PLowell (M1Val); PDuarte (M4), YBarcelona (p.Pro39His). Gene-sequencing (46.7%) detected Q0GraniteFalls, Q0Saint-Etienne, Q0Amersfoort(M1Ala), MWürzburg, NHartfordcity and one novel-variant (c.1A>G) named Q0Attikon.Heterozygous included PI*MQ0Amersfoort(M1Ala), PI*MMProcida, PI*Mp.(Asp280Val), PI*MOFeyzin. AAT-levels were significantly different between genotypes (p = 0.002).

CONCLUSION

Genotyping AATD in Greece, a multiplicity of rare variants and a diversity of rare combinations, including unique ones were observed in two thirds of patients, expanding knowledge regarding European geographical trend in rare variants. Gene sequencing was necessary for genetic diagnosis. In the future the detection of rare genotypes may add to personalize preventive and therapeutic measures.

[Guideline for the Diagnosis and Treatment of Asthma - Addendum 2020 - Guideline of the German Respiratory Society and the German Atemwegsliga in Cooperation with the Paediatric Respiratory Society and the Austrian Society of Pneumology]

The present addendum of the guideline for the diagnosis and treatment of asthma (2017) complements new insights into the diagnosis and management of asthma as well as for the newly approved drugs for the treatment of asthma. Current, evidence-based recommendations on diagnostic and therapeutic approaches are presented for children and adolescents as well as for adults with asthma.

COPD in Germany: Use of Diagnostic Measures Including Blood Eosinophil Counts in Daily Practice

BACKGROUND

 Accumulating evidence on the role of blood eosinophils as a biomarker prompted the Global Initiative for Chronic Obstructive Lung Disease (GOLD) committee to refine the existing treatment algorithm by incorporating eosinophil counts into treatment recommendations. However, there is a lack of data on when, why and how frequently such blood tests and other measures are being performed by German private respiratory specialists.

METHODS

 A questionnaire evaluating doctors' opinions on the use of diagnostic measures at initial diagnosis and during follow-up, including blood eosinophil count in patients with COPD, was completed by 27 respiratory specialists. Medical records from the past 12 months of 251 patients treated by the same physicians were reviewed retrospectively to investigate the use of these measures.

RESULTS

 Body plethysmography (100 % of doctors) and chest X-ray (96.3 %) were the most commonly used measures according to the doctor's questionnaire; other measures were COPD assessment test (CAT; 85.2 %) and blood eosinophil count (81.5 %). The evaluation of patients' medical records revealed that body plethysmography was performed in 72.7 %, the CAT in 61.8 % and chest X-ray in 40.6 % of patients. Blood eosinophil count was measured in 7.2 %.

CONCLUSIONS

 In line with the GOLD recommendations, these results confirm that lung function, imaging and patient-reported outcome questionnaires play a crucial role in managing COPD. Our analyses reveal that measurement of the blood eosinophil count gained importance due to physicians' increased awareness of these cells as a useful biomarker. However, this test seems to be performed mainly for initial diagnosis and not on a regular basis.

[Guideline for the Diagnosis and Treatment of Asthma - Guideline of the German Respiratory Society and the German Atemwegsliga in Cooperation with the Paediatric Respiratory Society and the Austrian Society of Pneumology]

The present guideline is a new version and an update of the guideline for the diagnosis and treatment of asthma, which replaces the previous version for german speaking countries from the year 2006. The wealth of new data on the pathophysiology and the phenotypes of asthma, and the expanded spectrum of diagnostic and therapeutic options necessitated a new version and an update. This guideline presents the current, evidence-based recommendations for the diagnosis and treatment of asthma, for children and adolescents as well as for adults with asthma.

Altered blood levels of vitamin D, cathelicidin and parathyroid hormone in patients with sepsis-a pilot study

It has been recognised that vitamin D (VitD) has a potential role in the regulation of inflammation and protection from infection. In a prospective clinical observational pilot study, we investigated the serum levels of 25-hydroxyvitamin-D3 (25(OH)D3), 1,25-hydroxyvitamin-D3 (1,25(OH)2D3), parathyroid hormone (PTH), and cathelicidin in intensive care unit (ICU) patients with or without systemic inflammatory response syndrome (SIRS). We included 32 patients with SIRS (septic patients), 16 ICU patients without SIRS, and 16 healthy controls. To substantiate the findings of the clinical study, we stimulated monocyte-derived macrophages with microbial patterns and analysed the impact of VitD on release of cytokines and antimicrobial activity. We found that patients with or without SIRS had relatively low levels of 25(OH)D3 and 1,25(OH)2D3. Patients with sepsis had significantly lower levels of 25(OH)D3 as compared to ICU control patients and healthy controls (10.53 ± 11.3 µg/l versus 16.46 ± 12.58 µg/l versus 24.04 ± 12.07 µg/l); the same was true for 1,25(OH)2D3. Serum levels of PTH and cathelicidin were significantly increased in sepsis patients, as compared to the other groups. In vitro, VitD significantly decreased the release of pro-inflammatory cytokines from macrophages and increased the antimicrobial activity of the cells. We concluded that patients with sepsis have significantly lower VitD levels. In vitro, VitD modulates inflammation and increases the antibacterial activity of innate immune cells. These findings suggest that VitD insufficiency is mechanistically related to increased susceptibility to SIRS and sepsis.

[Expert statement for augmentation therapy in patients with alpha-1 antitrypsin deficiency]

Augmentation therapy in Alpha-1 Antitrypsin Deficiency aims to reduce the progression of lung emphysema, to reduce exacerbation frequency, and to improve quality of life. This expert statement briefly summarizes the most important treatment studies performed in patients with Alpha-1 Antitrypsin Deficiency and severe lung emphysema. Indications and contraindications for long-term intravenous augmentation therapy with human Alpha-1 Antitrypsin are derived from the available study results. Safety issues and the controversies of this topic are discussed in detail.

[Chronic obstructive pulmonary disease : new pharmacotherapeutic options]

Data about the clinical presentation of chronic obstructive pulmonary disease (COPD) have resulted in a new classification of the disease. The degree of airflow limitation has been amended by symptoms and exacerbation rate. The standard pharmacotherapy of stable COPD is in transition, as fixed combinations of long acting beta agonists and long acting anticholinergics are in the late stages of clinical development. On this background inhaled corticosteroids will need to be re-evaluated. Roflumilast is a recently approved therapeutic option that primarily diminishes exacerbation frequency in patients with chronic bronchitis and severe airflow obstruction (FEV(1) < 50%). In COPD patients with acute exacerbations procalcitonin levels can be used to guide antibiotic therapy. Comparable clinical outcomes can be achieved while using significantly less amounts of antibiotics.

The effects of weekly augmentation therapy in patients with PiZZ α1-antitrypsin deficiency

Background

The major concept behind augmentation therapy with human α₁-antitrypsin (AAT) is to raise the levels of AAT in patients with protease inhibitor phenotype ZZ (Glu342Lys)-inherited AAT deficiency and to protect lung tissues from proteolysis and progression of emphysema.

Objective

To evaluate the short-term effects of augmentation therapy (Prolastin^®) on plasma levels of AAT, C-reactive protein, and chemokines/cytokines.

Materials and methods

Serum and exhaled breath condensate were collected from individuals with protease inhibitor phenotype ZZ AAT deficiency-related emphysema (n = 12) on the first, third, and seventh day after the infusion of intravenous Prolastin. Concentrations of total and polymeric AAT, interleukin-8 (IL-8), monocyte chemotactic protein-1, IL-6, tumor necrosis factor-α, vascular endothelial growth factor, and C-reactive protein were determined. Blood neutrophils and primary epithelial cells were also exposed to Prolastin (1 mg/mL).

Results

There were significant fluctuations in serum (but not in exhaled breath condensate) levels of AAT polymers, IL-8, monocyte chemotactic protein-1, IL-6, tumor necrosis factor-α, and vascular endothelial growth factor within a week of augmentation therapy. In general, augmented individuals had higher AAT and lower serum levels of IL-8 than nonaugmented subjects. Prolastin added for 3 hours to neutrophils from protease inhibitor phenotype ZZ individuals in vitro reduced IL-8 release but showed no effect on cytokine/chemokine release from human bronchial epithelial cells.

Conclusion

Within a week, augmentation with Prolastin induced fluctuations in serum levels of AAT polymers and cytokine/chemokines but specifically lowered IL-8 levels. It remains to be determined whether these effects are related to the Prolastin preparation per se or to the therapeutic efficacy of augmentation with AAT.