scholarly journals Alternative detection of SARS-CoV-2 RNA by a new assay based on mass spectrometry

Author(s):  
Evelyn Stelzl ◽  
Harald H. Kessler ◽  
Hans G. Mustafa ◽  
Maria E. Mustafa ◽  
Brigitte I. Santner ◽  
...  

Abstract Objectives Accurate detection of SARS-CoV-2 RNA is essential to stopping the spread of SARS-CoV-2. The aim of this study was to evaluate the performance of the recently introduced MassARRAY® SARS-CoV-2 Panel and to compare it to the cobas® SARS-CoV-2 Test. Methods The MassARRAY® SARS-CoV-2 Panel consists of five assays targeting different sequences of the SARS-CoV-2 genome. Accuracy was determined using national and international proficiency panels including 27 samples. For clinical evaluation, 101 residual clinical samples were analyzed and results compared. Samples had been tested for SARS-CoV-2 RNA with the cobas® SARS-CoV-2 Test. Results When accuracy was tested with the MassARRAY® SARS-CoV-2 Panel, 25 of 27 (92.6%) samples revealed correct results. When clinical samples were analyzed with the MassARRAY® SARS-CoV-2 Panel and compared to the cobas® SARS-CoV-2 Test, 100 samples showed concordant results. One sample was found to be inconclusive with the MassARRAY® SARS-CoV-2 Panel. When time-to-results were compared, the new assay showed longer total and hands-on times. Conclusions The MassARRAY® SARS-CoV-2 Panel showed a good performance and proved to be suitable for use in the routine diagnostic laboratory. Especially during phases of shortage of reagents and/or disposables, the new test system appears as beneficial alternative to standard assays used for detection of SARS-CoV-2 RNA.

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 849 ◽  
Author(s):  
Petra Wandernoth ◽  
Katharina Kriegsmann ◽  
Cristina Groh-Mohanu ◽  
Martin Daeumer ◽  
Peter Gohl ◽  
...  

Background: Amplification of viral ribonucleic acid (RNA) by real-time reverse transcriptase polymerase chain reaction (rRT-PCR) is the gold standard to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the initial outbreak, strategies to detect and isolate patients have been important to avoid uncontrolled viral spread. Although testing capacities have been upscaled, there is still a need for reliable high throughput test systems, specifically those that require alternative consumables. Therefore, we tested and compared two different methods for the detection of viral PCR products: rRT-PCR and mass spectrometry (MS). Methods: Viral RNA was isolated and amplified from oro- or nasopharyngeal swabs. A total of 22 samples that tested positive and 22 samples that tested negative for SARS-CoV-2 by rRT-PCR were analyzed by MS. Results of the rRT-PCR and the MS protocol were compared. Results: Results of rRT-PCR and the MS test system were in concordance in all samples. Time-to-results was faster for rRT-PCR. Hands-on-time was comparable in both assays. Conclusions: MS is a fast, reliable and cost-effective alternative for the detection of SARS-CoV-2 from oral and nasopharyngeal swabs.


2000 ◽  
Author(s):  
Tibor I. Kesztyues ◽  
M. Mehlitz ◽  
E. Schilken ◽  
G. Weniger ◽  
S. Wolf ◽  
...  

2020 ◽  
Vol 21 (19) ◽  
pp. 7330
Author(s):  
Roberta Noberini ◽  
Cristina Morales Torres ◽  
Evelyn Oliva Savoia ◽  
Stefania Brandini ◽  
Maria Giovanna Jodice ◽  
...  

Epigenetic aberrations have been recognized as important contributors to cancer onset and development, and increasing evidence suggests that linker histone H1 variants may serve as biomarkers useful for patient stratification, as well as play an important role as drivers in cancer. Although traditionally histone H1 levels have been studied using antibody-based methods and RNA expression, these approaches suffer from limitations. Mass spectrometry (MS)-based proteomics represents the ideal tool to accurately quantify relative changes in protein abundance within complex samples. In this study, we used a label-free quantification approach to simultaneously analyze all somatic histone H1 variants in clinical samples and verified its applicability to laser micro-dissected tissue areas containing as low as 1000 cells. We then applied it to breast cancer patient samples, identifying differences in linker histone variants patters in primary triple-negative breast tumors with and without relapse after chemotherapy. This study highlights how label-free quantitation by MS is a valuable option to accurately quantitate histone H1 levels in different types of clinical samples, including very low-abundance patient tissues.


2004 ◽  
Vol 50 (2) ◽  
pp. 306-312 ◽  
Author(s):  
Stefan S Biel ◽  
Andreas Nitsche ◽  
Andreas Kurth ◽  
Wolfgang Siegert ◽  
Muhsin Özel ◽  
...  

Abstract Background: We studied electron microscopy (EM) as an appropriate test system for the detection of polyomavirus in urine samples from bone marrow transplant patients. Methods: We evaluated direct EM, ultracentrifugation (UC) before EM, and solid-phase immuno-EM (SPIEM). The diagnostic accuracy of EM was studied by comparison with a real-time PCR assay on 531 clinical samples. Results: The detection rate of EM was increased by UC and SPIEM. On 531 clinical urine samples, the diagnostic sensitivity of EM was 47% (70 of 149) with a specificity of 100%. We observed a linear relationship between viral genome concentration and the proportion of urine samples positive by EM, with a 50% probability for a positive EM result for urine samples with a polyomavirus concentration of 106 genome-equivalents (GE)/mL; the probability of a positive EM result was 0% for urine samples with <103 GE/mL and 100% for urine samples containing 109 GE/mL. Conclusions: UC/EM is rapid and highly specific for polyomavirus in urine. Unlike real-time PCR, EM has low sensitivity and cannot quantify the viral load.


Resuscitation ◽  
2015 ◽  
Vol 90 ◽  
pp. 163-167 ◽  
Author(s):  
Charles D. Deakin ◽  
Jakob E. Thomsen ◽  
Bo Løfgren ◽  
Graham W. Petley

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012893
Author(s):  
Makoto Ohno ◽  
Yoshiharu Hayashi ◽  
Hiroaki Aikawa ◽  
Mitsuhiro Hayashi ◽  
Yasuji Miyakita ◽  
...  

ObjectiveMutant isocitrate dehydrogenase (IDH) 1/2 gene products gain a new ability to produce D-2-hydroxyglutarate (D2HG). IDH1/2 mutations are thought to be associated with seizures owing to the structural similarity between D2HG and glutamate. However, the effects of D2HG on seizures in clinical settings are not fully understood. We, therefore, sought to investigate the relationship between tissue 2-hydroxyglutarate (2HG) concentration and preoperative seizures using clinical samples.MethodsWe included consecutive 104 patients with diffuse glioma who underwent surgery from August 2008 to May 2016 and whose clinical presentation and IDH1/2 status were identified. The presence of preoperative seizures, tumor location, histopathological diagnosis, IDH1/2 status, and 1p/19q codeletion were assessed from the patient charts. Tissue 2HG concentration was measured using liquid chromatography–tandem mass spectrometry. To evaluate 2HG distribution without artefactual tissue disruption, we applied matrix-assisted laser desorption/ionization high resolution mass spectrometry imaging (MALDI–MSI) in 12 patients’ surgically resected samples. We assessed the correlation of preoperative seizures with tissue 2HG concentration, IDH1/2 status, WHO grade, and 1p/19q codeletion.ResultsTissue 2HG concentration was higher in IDH1/2 mutant tumors (IDH-Mut) than in IDH1/2 wildtype tumors (IDH-WT) (median: 4860 ng/mg vs 75 ng/mg) (p < 0.0001). MALDI–MSI could detect 2HG signals in IDH-Mut, but not in IDH-WT. Preoperative seizures were observed in 64.3% patients with IDH-Mut and 21.0% patients with IDH-WT (p < 0.0001). The optimal cutoff value of tissue 2HG concentration for predicting preoperative seizures was 1190 ng/mg, as calculated by the receiver operating characteristic curve. Increased preoperative seizure risk was only observed in tumors with 2HG concentration above the cutoff value among IDH-Mut (IDH-Mut with above the cutoff value: 71.4 % vs IDH-Mut with below the cutoff value: 28.6 %, p = 0.031). Multivariate analysis, including IDH1/2 mutation status, tissue 2HG concentration, WHO grade and 1p/19q codeletion, revealed that only increased tissue 2HG concentration was associated with preoperative seizures (odds ratio 5.86, 95% confidence interval 1.02–48.5, p = 0.048).ConclusionsWe showed that high tissue 2HG concentration was associated with preoperative seizures, suggesting that excess 2HG increases risk of preoperative seizures in IDH1/2 mutant tumors.


Author(s):  
Scott Wilschefski ◽  
Matthew Baxter ◽  
Gertruida Pool

Background The measurement of selenium in human plasma is useful to assess deficiency or toxicity. The presence of gadolinium in clinical samples following administration of certain contrast agents used for magnetic resonance imaging can cause a significant positive bias in selenium results when measured using quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS). Methods A mathematical equation to correct for gadolinium interference was assessed using both patient samples and commercial quality control/external quality assurance (QC/EQA) materials spiked with gadolinium. Samples were analysed using an Agilent 7900 ICP-MS operated in ‘narrow peak’ (half-mass) mode. Accuracy was evaluated by comparing corrected selenium results with target concentrations. Results Corrected results were found to be accurate at all gadolinium concentrations tested (2, 4, 10 and 20 mg/L). Average recoveries ranged from 97.4 to 106.5%. Results for QC/EQA materials were within specified target ranges. Within-run imprecision was <3%, and between-run imprecision was <4.3%, demonstrating robustness. Conclusions The correction equation described here is a simple method to correct for gadolinium interference on plasma selenium measurement using ICP-MS. This approach eliminates the need for specimen recollections, and improves patient care by reducing laboratory turnaround times and preventing delays in diagnosis/treatment.


Viruses ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1054 ◽  
Author(s):  
Mohamed S. H. Hassan ◽  
Davor Ojkic ◽  
Carla S. Coffin ◽  
Susan C. Cork ◽  
Frank van der Meer ◽  
...  

Infectious bronchitis virus (IBV) infection in chickens can lead to an economically important disease, namely, infectious bronchitis (IB). New IBV variants are continuously emerging, which complicates vaccination-based IB control. In this study, five IBVs were isolated from clinical samples submitted to a diagnostic laboratory in Ontario, Canada, and subjected to detailed molecular characterization. Analysis of the spike (S)1 gene showed that these five IBVs were highly related to the Delmarva (DMV/1639) strain (~97.0% nucleotide sequence similarity) that was firstly isolated from an IB outbreak in the Delmarva peninsula, United States of America (USA), in 2011. However, the complete genomic sequence analysis showed a 93.5–93.7% similarity with the Connecticut (Conn) vaccine strain, suggesting that Conn-like viruses contributed to the evolution of the five Canadian IBV/DMV isolates. A SimPlot analysis of the complete genomic sequence showed evidence of recombination for at least three different IBV strains, including a Conn vaccine-like strain, a 4/91 vaccine-like strain, and one strain that is yet-unidentified. The unidentified strain may have contributed the genomic regions of the S, 3, and membrane (M) genes of the five Canadian IBV/DMV isolates. The study outcomes add to the existing knowledge about involvement of recombination in IBV evolution.


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