Direct comparison of Altona-SARS-CoV-2 dual target RT-qPCR Assay with commercial LAMP Assay using throat washes in health care staff testing.

Background: Rapid molecular diagnostics by PCR has a crucial role in handling the global SARS-CoV-2 pandemic. As diagnoses are time-sensitive and global supply chains are susceptible to various factors alternative detection methods would be an important backup. Objectives: During the study the performance of a commercially available isothermal LAMP method for SARS-CoV-2 detection was compared to a IVD RT-PCR Assays using throat wash specimens that were routinely taken in our hospital setting. Study design: Throat wash specimens of hospital staff (n = 174) previously tested positive for SARS-CoV-2 by the Altona Diagnostics RealStar SARS-CoV-2 RT-PCR (Altona Diagnostics, Hamburg, Germany) was tested for SARS-CoV-2 also by the SARS-CoV-2 Rapid Colorimetric LAMP Assay (NEB Germany GmbH, Frankfurt a.M., Germany). Results: The sensitivity of the colorimetric LAMP Assay compared to RT-qPCR was 78.74%, and the specificity was determined to 88.24% with a positive predictive value of 0.986 and a negative predicitve value of 0.882. The positive and negative likelihood ratio for LAMP was 6.693 and 0.241, respectively, while the diagnostic odds ratio was 27.77. Conclusions: In times of limited PCR test ressources and in settings with limited PCR capacities, the colorimetric LAMP Assay could serve as an alternative, if a calculable loss of sensitivity is acceptable from the Public Health perspective in certain settings.

Comparison of Biocartis IDYLLA ™ cartridge assay with Qiagen GeneReader NGS for detection of targetable mutations in EGFR, KRAS/NRAS, and BRAF genes.

Lung and colorectal cancers (CRC) have two of the highest mortality rates among all cancer types, and their occurrence and the need for personalized diagnostics and subsequent therapy were not influenced by the COVID-19 pandemics. However, due to the disruption of established delivery chains, standard assays for in vitro diagnostics of those cancers were temporarily not available, forcing us to implement alternative testing methods that enabled at least basic therapy decision making. For this reason, we evaluated rapid testing on the Biocartis Idylla™ platform (Biocartis, Mechelen, Belgium) for four important genes commonly mutated in lung and colorectal cancers, namely EGFR, NRAS, KRAS, and BRAF. Clinical specimens from which the mutation status has previously been determined using Next Generation Sequencing (NGS), were retested to determine whether Idylla™ can offer accurate results. To compare the results, the sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) are calculated for each of the mutation types and then combined to determine the values of the Idylla™ system in total, while setting NGS as the gold-standard basis the assays were compared with. Idylla testing thereby displayed acceptable sensitivity and specificity and delivered reliable results for initial therapy decisions.

Differential cytology profiles in bronchoalveolar lavage (BAL) in COVID-19 patients: A descriptive observation and comparison with other corona viruses, Influenza virus, Haemophilus influenzae, and Pneumocystis jirovecii.

ABSTRACT: Brochoalvelolar lavages (BALs) from patients suffering from hospitalized infections with SARS-CoV-2, other corona viruses (human coronavirus (HCoV)-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1), Influenza virus type A and B, Haemophilus influenzae and Pneumocystis jirovecii were compared cytopathologically.The aim of the study was to evaluate if the cellular profile detectable in BAL may be specific for the respective pathogens and could lead to diagnosis of COVID-19 even in the absence of PCR results.Differential cytology and flow cytometry datasets of 62 patients were observed and compared.We observed a significant association between individual cell pattern changes and the causing pathogen, but no general cell distribution pattern.The cytology pattern of the BAL fluid in COVID-19 is not specific enough to use it as a sole diagnostic criterion, although it may support clinical decision making.

Limits and Opportunities of SARS-CoV-2 Antigen Rapid Tests: An Experienced-Based Perspective.

BACKGROUND: Due to the steadily rising case numbers of SARS-CoV-2 infections worldwide, there is an increasing need for reliable rapid diagnostic devices in addition to existing gold standard PCR methods. Actually, public attention is focused on antigen assays including lateral flow tests (LFTs) as a diagnostic alternative. Therefore, different LFTs were analyzed regarding their performance in a clinical setting. MATERIAL AND METHODS: A pilot sample panel of 13 bronchoalveolar fluids (BALFs) and 60 throat washing (TW) samples with confirmed PCR results, as well as eight throat washes invalid by PCR, were tested with the BIOCREDIT test (RapiGEN), the PanbioTM assay (Abbott), and the SARS-CoV-2 rapid antigen test (Roche). CONCLUSION: The analyzed antigen test showed an interassay correlation of 27.4%, with overall specificities ranging from 19.4% to 87.1%, while sensitivities of the respective tests ranged between 33.3% and 88.1%. Because these assays did not entirely meet all high expectations, their benefit has to be carefully evaluated for the respective test strategy and setting.

NGS-dataset of putative driver mutations associated with benign peritoneal strumosis.

A rare case of benign peritoneal strumosis was screened for driver mutations in genes relevant to currently approved cancer therapies. Therefore, three formalin fixed paraffin embedded issue sections were screened with the GeneReader Actionable Insights NGS panel (Qiagen, Hilden, Germany) for the occurrence of driver mutations. Several mutations were identified in drug-targetable genes, such as ALK, EGFR, and BRAF. The majority of identified mutations were single nucleotide variant, but also a insertion/deletion mutation was identified. The presented dataset is the first NGS dataset available from a patient with benign peritoneal strumosis.

Detailed overview on the mutations detected by and the sensitivity of the GeneReader NGS sequencing platform.

This article presents additional next generation data from our pre-clinical validation study. In total 121 samples (clinical specimen and interlaboratory test samples) were tested successfully with next generation sequencing. 38 different mutations in six different genes were detected. Next to the detection of different mutations, the reproducibility of the NGS test was analyzed. Three samples were analyzed five times and the results were compared. Several mutations classified as non-pathogenic so far, have been detected repeatedly.

Pre-clinical validation of a next generation sequencing testing panel.

OBJECTIVE: Next Generation Sequencing (NGS) has become a useful tool for gene mutation testing which is required for targeted therapies. The aim of this study was to validate the GeneRead QIAact Actionable Insights Tumor Panel (Qiagen) on the GeneReader System in a diagnostic laboratory setting. METHODS: The GeneRead QIAact Actionable Insights Tumor Panel allows the analysis of 773 variant positions in 12 genes (ALK, BRAF, EGFR, ERBB2, ERBB3, ESR1, KIT, KRAS, NRAS, PDGFRA, PIK3CA and RAF1). For the validation of the panel we used a commercial available multiplex reference standard carrying 11 mutations in defined positions, samples from interlaboratory tests, and FFPE tumor samples from patients which were tested previously for mutations in KRAS, NRAS, BRAF, EGFR, KIT, and/or PDGFRA with pyrosequencing. RESULTS: Among the 122 tested samples, 121 samples (99.2%) were successfully sequenced. The sensitivity and specificity for detecting variants was 100% and results proved to be reproducible and precise. 119 (98.3%) results were concordant to the expected results. The differences between NGS and pyrosequencing observed in two samples were due to a wrong analysis by the pyrosequencing software which did not cover the present mutations. CONCLUSION: Overall, the GeneRead QIAact Actionable Insights Tumor Panel was specific and sensitive for mutation analysis for targeted therapies and can be incorporated into laboratory diagnostics' daily practice.

Epidemiology of driver mutations in lung cancer in a German tertiary hospital in patients with testing indication.

BACKGROUND: KRAS, BRAF, EGFR and ALK-mutation testing is a prerequisite for non-small-cell lung cancer treatments, but there remains limited epidemiological information about such mutations in German cohorts. MATERIALS & METHODS: Between February 2010 and June 2015, a total of 1080 tumor samples from 1019 non-small-cell lung cancer patients were analyzed for KRAS, BRAF, EGFR and ALK-mutations by Therascreen-pyrosequencing and FISH. RESULTS: Mutation patterns differed dependent on the histological subtype and sex. Mainly, adenocarcinomas were mutated and formed the major histological group. Double mutations were observed also not explicitly screened for. In our German cohort, female adenocarcinoma patients had statistically significantly higher rates EGFR mutations than male patients. DISCUSSION: The different mutation patterns dependent on histological phenotypes warrant further epidemiological studies while suggesting different mechanisms of cancerogenesis.

Low Titer Pneumocystis jirovecii Infections: More than Just Colonization?

Non-pneumonia Pneumocystis jirovecii colonization is thought to occur frequently in immunocompetent individuals. The aim was to analyze if P. jirovecii low-titer detections have more impact than just colonization. From our total cohort of patients for which P. jirovecii testing by qPCR was requested, we selected exclusively those that were fully immunocompetent. Patients were defined as fully immunocompetent if they did not receive immunosuppressive therapy, displayed regular antibody titers, and did not suffer from acquired, inherited or autoimmune diseases. Only those patients with complete medical records available were included. A retrospective analysis identified patients with P. jirovecii colonization and successful antibiotic therapy in response to laboratory pathogen detection. We identified 30 fully immunocompetent patients with P. jirovecii colonization suspected to suffer from infection with the pathogen, but with milder symptoms than pneumonia. All patients were successfully treated with cotrimoxazole against P. jirovecii and resolved from chronic cough and recurrent pulmonary infections. The fact that all patients displayed recovery from their clinical symptoms gives raise to the hypothesis that P. jirovecii infections may also occur in immunocompetent patients but with milder symptoms.

Low frequency of EGFR mutations in pleural mesothelioma patients, Cologne, Germany.

EGFR mutations were previously found in patients suffering from peritoneal mesothelioma but have not yet been described in pleural mesothelioma. The aim of the present study was the identification of EGFR mutations in patients suffering from pleural mesothelioma. Pleural mesothelioma tissue from 31 patients was used to analyze possible mutations in the EGFR gene comprising the exons 18-21 with the codons 719, 768, 790, 858+861, 731+734, 785, 797+801, 831, and 868 with pyrosequencing. The results indicate that 31 pleural mesothelioma patients show a wild-type EGFR gene when analyzing the codons D19, 768, 790, 858+861, 731+734, 785, 797+801, 831, and 868, whereas 2 patients have a mutation in the EGFR gene in codon 719. Sanger sequencing of the EGFR codon 785 was used for the determination of a polymorphism in the sequencing of tumor-free patients and pleural mesothelioma patients with a distribution of a wild-type homozygous sequence with guanine, a wild-type heterozygous sequence having guanine and adenine, a wild-type homozygous sequence with adenine, and a wild-type heterozygous sequence with adenine and guanine. Next, the identification of less EGFR mutations in the EGFR gene of the pleural mesothelioma an up to this time unknown polymorphism in the EGFR gene was identified which could be wrongly interpreted as a mutation.

Pneumocystis jirovecii can be productively cultured in differentiated CuFi-8 airway cells.

UNLABELLED: Although Pneumocystis jirovecii is a well-known and serious pathogen, all previous attempts to isolate, cultivate, and propagate this fungus have failed. This serious challenge in microbiology was addressed in the present study. We examined whether P. jirovecii could be cultured in a permanent three-dimensional air-liquid interface culture system formed by CuFi-8 cells, a differentiated pseudostratified airway epithelial cell line. Cultured pseudostratified cells were inoculated with bronchoalveolar fluid that had been confirmed to be positive for P. jirovecii using PCR. Five days later, the cells and basal medium were harvested and tested for P. jirovecii using quantitative PCR (qPCR), commercially available immunofluorescence detection assays, and Grocott staining of formalin-fixed, paraffin-embedded thin sections of infected-cell cultures. We successfully productively cultivated and propagated P. jirovecii from these P. jirovecii-positive bronchoalveolar lavage fluid (BALF) samples. Furthermore, we provide evidence that P. jirovecii induced cytopathic effects on lung epithelial cells and was even invasive in cell culture. To the best of our knowledge, the cell culture system developed herein represents the first methodology to enable molecular analyses of this pathogen's life cycle and further in vitro studies of P. jirovecii, such as assessments of drug sensitivity and resistance as well as investigations of the pathogen's stability against environmental factors and disinfectants. IMPORTANCE: This is the first report of the successful productive cultivation and propagation of Pneumocystis jirovecii, a human-pathogenic fungus of major clinical significance. These findings are groundbreaking because they will influence the field of diagnostic microbiology, facilitate the testing of antibiotics against P. jirovecii, and enable stability studies of this pathogen when exposed to the environmental factors and chemicals that hospitals are required to use for disinfection. Because productively culturing P. jirovecii has been attempted unsuccessfully for several decades, this study represents a breakthrough in this field.

Identification of uncommon PIK3CA mutations in lung cancer by using pyrosequencing.

INTRODUCTION: Phospatidylinositol-3-kinases (PI3K) play an important role in various cell processes. Oncogenic mutations in the PIK3CA gene, which codes for the catalytic subunit, have been identified in various malignancies and activate the PI3K/AKT/mTOR pathway, which is a critical driver of tumorigenesis. METHODS: We tested 41 tumor samples with known KRAS, BRAF, and EGFR mutation status for the occurrence of mutations in the PIK3CA gene, using a pyrosequencing assay. RESULTS: Pyrosequencing revealed 2 mutations (4.9%) in the PIK3CA gene, one in exon 9 and the other in exon 20. Both mutations have not been identified yet in lung tumor tissue. DISCUSSION: The screening of our small patient cohort by pyrosequencing identified 2 mutations (4.9%) in PIK3CA, one in exon 9 (Q546H) and the other in exon 20 (M1043T). Both mutations have not been described in lung tumors yet and seem to be rather uncommon mutations. Future screening of large patient cohorts with pyrosequencing may contribute to the detection of more mutations in lung cancer because of the low limit of detections of this method and may contribute to a better understanding of the interaction of mutations and tumorigenesis.

Combination of Pyrosequencing® and Sanger sequencing reveals alleged novel mutation in exon 18 of EGFR.

BACKGROUND: EGFR sequencing is crucial for therapeutic decisions in treatment regimens of lung cancer patients. Several mutations have been identified in the past, of which some were confirmed as activating or resistance mutations by in vitro phenotyping. In this study, novel mutations of so far unknown relevance were identified by a combination of Sanger and Pyrosequencing®. MATERIALS & METHODS: Formalin-fixed paraffin-embedded lung biopsies from 20 randomly selected patients suffering from non-small-cell lung cancer with previous external EGFR mutation analyses were reanalyzed by Sanger sequencing according to a previous study, and Pyrosequencing with the EGFR Pyro Kit (Qiagen, Hilden, Germany). Sensitivity and specificity were determined in comparison with the results of an external supplier for all relevant mutations in exons 18, 19, 20 and 21. RESULTS: Our analyses revealed that Pyrosequencing is faster and more sensitive for the common mutations compared with Sanger sequencing and the results of the external supplier. A new mutation, c.2160delC, in exon 18 in 40% of patients leading to a frameshift was identified. Another two frameshift mutations were detected in exon 18 in 10% of patients; c.2168delT in combination with c.2160delC, and c.2163insG alone. CONCLUSION: Divergences regarding the detection of the common mutations could be traced back to inhomogeneous or insufficient tumor material. Surprisingly, none of the newly identified mutations have been previously described, although they occurred in total in up to 40% of randomly selected cases. A possible explanation may be that commercial assays did not cover these deletions that are located nearby but not in the known mutation hotspot of exon 18, or that Sanger sequencing produced serious artifacts.

Comparison of two commercial PCR methods for methicillin-resistant Staphylococcus aureus (MRSA) screening in a tertiary care hospital.

Nose/throat-swabs from 1049 patients were screened for MRSA using CHROMagar MRSA, LightCycler Advanced MRSA, and Detect-Ready MRSA. Results were compared to the CHROMagar MRSA results, which was set as reference system. MRSA was detected in 3.05% of the patients with CHROMagar MRSA. LightCycler MRSA Advanced showed a higher clinical sensitivity (84.38%) than Detect-Ready MRSA (57.69%).The negative predictive values were high for both tests (>98%). The specificity and the positive predictive value were higher for the Detect-Ready MRSA test than for the LightCycler MRSA test (99.59% and 78.95% versus 98.52% and 64.29%). For routine screening LightCycler MRSA Advanced proved to be more efficient in our clinical setting as the clinical sensitivity was much higher than the sensitivity of Detect-Ready MRSA. CHROMagar MRSA detected more MRSA positive samples than both PCR methods, leading to the conclusion that the combination of PCR with cultural screening is still the most reliable way for the detection of MRSA. LightCycler MRSA Advanced was faster and needed less hands-on time. The advantage of Detect-Ready MRSA was the additional identification of methicillin-sensitive S.aureus (here in 34.63% of the samples), an information which can be possibly used for reducing the risk of postoperative infections in surgical patients in future.