Search

Contains fulltext : 238214.pdf (Publisher’s version ) (Open Access) Rapid diagnostics for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are paramount for reducing the spread of the current pandemic. During additional seasonal epidemics with influenza A/B and respiratory syncytial virus (RSV), the clinical signs and symptoms cannot be distinguished easily from SARS-CoV-2. Therefore, a new assay combining four targets in the form of the new Xpert Xpress SARS-CoV-2/Flu/RSV assay was evaluated. The assay was compared to the Xpert Xpress SARS-CoV-2, Xpert Xpress Flu/RSV, Seegene Flu/RSV, influenza A/B r-gene® and RSV/hMPV r-gene®. A total of 295 nasopharyngeal and throat swabs were tested at four institutes throughout Europe including 72 samples positive for SARS-CoV-2, 65 for influenza A, 47 for influenza B, and 77 for RSV. The sensitivity of the new assay was above 95% for all targets, with the highest for SARS-CoV-2 (97.2%). The overall correlation of SARS-CoV-2 Ct values between Xpert Xpress SARS-CoV-2 assay and Xpert Xpress SARS-CoV-2/Flu/RSV assay was high. The agreement between Ct values above 30 showed the multiplex giving higher Ct values for SARS-CoV-2 on average than the singleplex assay. In conclusion, the new assay is a rapid and reliable alternative with less hands-on time for the detection of not one, but four upper respiratory tract pathogens that may circulate at the same time.

Contains fulltext : 220114.pdf (Publisher’s version ) (Closed access) BACKGROUND: With the outbreak of SARS-CoV-2, rapid diagnostics are paramount to contain the current pandemic. The routinely used realtime RT-PCR is sensitive, specific and able to process large batches of samples. However, turnaround time is long and in cases where fast obtained results are critical, molecular point of care tests (POCT) can be an alternative. Here we report on a multicenter evaluation of the Cepheid Xpert Xpress SARS-CoV-2 point-of-care test. STUDY DESIGN: The Xpert Xpress SARS-CoV-2 assay was evaluated against the routine in-house real-time RT-PCR assays in three medical microbiology laboratories in The Netherlands. A sensitivity and specificity panel was tested consisting of a dilution series of SARS-CoV-2 and ten samples containing SARS-CoV-2 and a range of other seasonal respiratory viruses. Additionally, 58 samples of patients positive for SARS-CoV-2 with different viral loads and 30 tested negative samples in all three Dutch laboratories using an in-house RT-PCR, were evaluated using Cepheids Xpert Xpress SARS-CoV-2 cartridges. RESULTS: Xpert Xpress SARS-CoV-2 point of care test showed equal performance compared to routine in-house testing with a limit of detection (LOD) of 8.26 copies/mL. Other seasonal respiratory viruses were not detected. In clinical samples Xpert Xpress SARS-CoV-2 reaches an agreement of 100 % compared to all in-house RT-PCRs CONCLUSION: Cepheids GeneXpert Xpert Xpress SARS-CoV-2 is a valuable addition for laboratories in situations where rapid and accurate diagnostics are of the essence.

OBJECTIVE: Plasmacytoid dendritic cells (PDCs) are a critical source of type I interferons (IFNs) that can contribute to the onset and maintenance of autoimmunity. Molecular mechanisms leading to PDC dysregulation and a persistent type I IFN signature are largely unexplored, especially in patients with systemic sclerosis (SSc), a disease in which PDCs infiltrate fibrotic skin lesions and produce higher levels of IFNalpha than those in healthy controls. This study was undertaken to investigate potential microRNA (miRNA)-mediated epigenetic mechanisms underlying PDC dysregulation and type I IFN production in SSc. METHODS: We performed miRNA expression profiling and validation in highly purified PDCs obtained from the peripheral blood of 3 independent cohorts of healthy controls and SSc patients. Possible functions of miRNA-618 (miR-618) on PDC biology were identified by overexpression in healthy PDCs. RESULTS: Expression of miR-618 was up-regulated in PDCs from SSc patients, including those with early disease who did not present with skin fibrosis. IFN regulatory factor 8, a crucial transcription factor for PDC development and activation, was identified as a target of miR-618. Overexpression of miR-618 reduced the development of PDCs from CD34+ cells in vitro and enhanced their ability to secrete IFNalpha, mimicking the PDC phenotype observed in SSc patients. CONCLUSION: Up-regulation of miR-618 suppresses the development of PDCs and increases their ability to secrete IFNalpha, potentially contributing to the type I IFN signature observed in SSc patients. Considering the importance of PDCs in the pathogenesis of SSc and other diseases characterized by a type I IFN signature, miR-618 potentially represents an important epigenetic target to regulate immune system homeostasis in these conditions.

HIV presents one of the highest evolutionary rates ever detected and combination antiretroviral therapy is needed to overcome the plasticity of the virus population and control viral replication. Conventional treatments lack the ability to clear the latent reservoir, which remains the major obstacle towards a cure. Novel strategies, such as CRISPR/Cas9 gRNA-based genome-editing, can permanently disrupt the HIV genome. However, HIV genome-editing may accelerate viral escape, questioning the feasibility of the approach. Here, we demonstrate that CRISPR/Cas9 targeting of single HIV loci, only partially inhibits HIV replication and facilitates rapid viral escape at the target site. A combinatorial approach of two strong gRNAs targeting different regions of the HIV genome can completely abrogate viral replication and prevent viral escape. Our data shows that the accelerating effect of gene-editing on viral escape can be overcome and as such gene-editing may provide a future alternative for control of HIV-infection.