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In patients with severe or critical Coronavirus disease 2019 (COVID-19) manifestations, a thromboinflammatory syndrome, with diffuse microvascular thrombosis, is increasingly evident as the final step of pro-inflammatory cytokines storm. Actually, no proven effective therapies for novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection exist. Preliminary observations on anticoagulant therapy appear to be associated with better outcomes in moderate and severe COVID-19 patients with signs of coagulopathy and in those requiring mechanical ventilation. The pathophysiology underlying the prothrombotic state elicited by SARS-CoV-2 outlines possible protective mechanisms of antithrombotic therapy (in primis anticoagulants) for this viral illness. The indications for antiplatelet/anticoagulant use (prevention, prophylaxis, therapy) are guided by the clinical context and the COVID-19 severity. We provide a practical approach on antithrombotic therapy management for COVID-19 patients from a multidisciplinary point of view., Highlights • An endothelial thromboinflammatory syndrome is involved in severe COVID-19 manifestations. • A pathophysiological rationale (anti-inflammatory and direct antiviral effects) motivates the use of antithrombotic therapy • Anticoagulant therapy is associated with better outcomes in case of coagulopathy and mechanical ventilation. • A potential role for antithrombotic therapy in COVID-19 prevention and treatment needs further investigation.

The extremely rapid spread of the SARS-CoV-2 has already resulted in more than 1 million reported deaths of coronavirus disease 2019 (COVID-19). The ability of infectious particles to persist on environmental surfaces is potentially considered a factor for viral spreading. Therefore, limiting viral diffusion in public environments should be achieved with correct disinfection of objects, tissues, and clothes. This study proves how two widespread disinfection systems, short-wavelength ultraviolet light (UV-C) and ozone (O3), are active in vitro on different commonly used materials. The development of devices equipped with UV-C, or ozone generators, may prevent the virus from spreading in public places.

The dependence of development and homeostasis in animals on the interaction of hundreds of extracellular regulatory proteins with the peri- and extracellular glycosaminoglycan heparan sulfate (HS) is exploited by many microbial pathogens as a means of adherence and invasion. Heparin, a widely used anticoagulant drug, is structurally similar to HS and is a common experimental proxy. Exogenous heparin prevents infection by a range of viruses, including S-associated coronavirus isolate HSR1. Here, we show that heparin inhibits severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) invasion of Vero cells by up to 80% at doses achievable through prophylaxis and, particularly relevant, within the range deliverable by nebulisation. Surface plasmon resonance and circular dichroism spectroscopy demonstrate that heparin and enoxaparin, a low-molecular-weight heparin which is a clinical anticoagulant, bind and induce a conformational change in the spike (S1) protein receptor-binding domain (S1 RBD) of SARS-CoV-2. A library of heparin derivatives and size-defined fragments were used to probe the structural basis of this interaction. Binding to the RBD is more strongly dependent on the presence of 2-O or 6-O sulfate groups than on N-sulfation and a hexasaccharide is the minimum size required for secondary structural changes to be induced in the RBD. It is likely that inhibition of viral infection arises from an overlap between the binding sites of heparin/HS on S1 RBD and that of the angiotensin-converting enzyme 2. The results suggest a route for the rapid development of a first-line therapeutic by repurposing heparin and its derivatives as antiviral agents against SARS-CoV-2 and other members of the Coronaviridae.

The SARS-CoV-2 virus has a complex transcriptome characterised by multiple, nested subgenomic RNAsused to express structural and accessory proteins. Long-read sequencing technologies such as nanopore direct RNA sequencing can recover full-length transcripts, greatly simplifying the assembly of structurally complex RNAs. However, these techniques do not detect the 5′ cap, thus preventing reliable identification and quantification of full-length, coding transcript models. Here we used Nanopore ReCappable Sequencing (NRCeq), a new technique that can identify capped full-length RNAs, to assemble a complete annotation of SARS-CoV-2 sgRNAs and annotate the location of capping sites across the viral genome. We obtained robust estimates of sgRNA expression across cell lines and viral isolates and identified novel canonical and non-canonical sgRNAs, including one that uses a previously un-annotated leader-to-body junction site. The data generated in this work constitute a useful resource for the scientific community and provide important insights into the mechanisms that regulate the transcription of SARS-CoV-2 sgRNAs.

The E1 and E2 envelope proteins of hepatitis C virus (HCV) form a heterodimer that drives virus-host membrane fusion. Here, we analyze the role of each amino acid in E1E2 function, expressing 545 individual alanine mutants of E1E2 in human cells, incorporating them into infectious viral pseudoparticles, and testing them against 37 different monoclonal antibodies (MAbs) to ascertain full-length translation, folding, heterodimer assembly, CD81 binding, viral pseudoparticle incorporation, and infectivity. We propose a model describing the role of each critical residue in E1E2 functionality and use it to examine how MAbs neutralize infection by exploiting functionally critical sites of vulnerability on E1E2. Our results suggest that E1E2 is a surprisingly fragile protein complex where even a single alanine mutation at 92% of positions disrupts its function. The amino-acid-level targets identified are highly conserved and functionally critical and can be exploited for improved therapies and vaccines.

Background Biobanks are imperative infrastructures, particularly during outbreaks, when there is an obligation to acquire and share knowledge as quick as possible to allow for implementation of science-based preventive, diagnostic, prognostic and therapeutic strategies. Methods We established a COVID-19 biobank with the aim of collecting high-quality and well-annotated human biospecimens, in the effort to understand the pathogenic mechanisms underlying COVID-19 and identify therapeutic targets (COVID-BioB, NCT04318366). Here we describe our experience and briefly review the characteristics of the biobanks for COVID-19 that have been so far established. Results A total of 46,677 samples have been collected from 913 participants (63.3% males, median [IQR] age 62.2 [51.2 - 74.0] years) since the beginning of the program. Most patients (66.9%) had been admitted to hospital for COVID-19, with a median length of stay of 15.0 (9.0 - 27.0) days. A minority of patients (13.3% of the total) had been admitted for other reasons and subsequently tested positive for SARS-CoV-2. The remainder were managed at home after being seen at the Emergency Department. Conclusions Having a solid research infrastructure already in place, along with flexibility and adaptability to new requirements, allowed for the quick building of a COVID-19 biobank that will help expand and share the knowledge of SARS-CoV-2.

Both emerging viruses and well-known viral pathogens endowed with neurotropism can either impair directly the neuronal functions or induce physio-pathological changes by diffusing from the periphery through neurosensory-epithelial connections. However, the current lack of anin vitrosystem modeling the connectivity between human neurons and peripheral tissues excludes the analysis of viral latency and reactivation and the assessment of natural/artificial induced anti-viral immunity. In this study, we developed the first stable topographic neurosensory-epithelial connection on-a-chip using human stem cell derived dorsal root ganglia (DRG) sensory neurons. Bulk and single cell transcriptomics showed that different combinations of key receptors for Herpes Simplex Virus 1 (HSV-1) are expressed by each sensory neuronal cell type. This neuronal-epithelial circuitry enabled a detailed analysis of the HSV infectivity faithfully modeling its dynamics and cell type specificity. The reconstitution of an organized connectivity between human sensory neurons and keratinocytes into microfluidic chips provides for the first time a powerfulin vitroplatform to model viral latency and reactivation of human viral pathogens.

The SARS-CoV-2 virus has a complex transcriptome characterised by multiple, nested sub genomic RNAs used to express structural and accessory proteins. Long-read sequencing technologies such as nanopore direct RNA sequencing can recover full-length transcripts, greatly simplifying the assembly of structurally complex RNAs. However, these techniques do not detect the 5′ cap, thus preventing reliable identification and quantification of full-length, coding transcript models. Here we used Nanopore ReCappable Sequencing (NRCeq), a new technique that can identify capped full-length RNAs, to assemble a complete annotation of SARS-CoV-2 sgRNAs and annotate the location of capping sites across the viral genome. We obtained robust estimates of sgRNA expression across cell lines and viral isolates and identified novel canonical and non-canonical sgRNAs, including one that uses a previously un-annotated leader-to-body junction site. The data generated in this work constitute a useful resource for the scientific community and provide important insights into the mechanisms that regulate the transcription of SARS-CoV-2 sgRNAs.

This contribution explores in a new statistical perspective the antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 141 coronavirus disease 2019 (COVID-19) patients exhibiting a broad range of clinical manifestations. This cohort accurately reflects the characteristics of the first wave of the SARS-CoV-2 pandemic in Italy. We determined the IgM, IgA, and IgG levels towards SARS-CoV-2 S1, S2, and NP antigens, evaluating their neutralizing activity and relationship with clinical signatures. Moreover, we longitudinally followed 72 patients up to 9 months postsymptoms onset to study the persistence of the levels of antibodies. Our results showed that the majority of COVID-19 patients developed an early virus-specific antibody response. The magnitude and the neutralizing properties of the response were heterogeneous regardless of the severity of the disease. Antibody levels dropped over time, even though spike reactive IgG and IgA were still detectable up to 9 months. Early baseline antibody levels were key drivers of the subsequent antibody production and the long-lasting protection against SARS-CoV-2. Importantly, we identified anti-S1 IgA as a good surrogate marker to predict the clinical course of COVID-19. Characterizing the antibody response after SARS-CoV-2 infection is relevant for the early clinical management of patients as soon as they are diagnosed and for implementing the current vaccination strategies.

SARS-CoV-2 proximal origin is still unclear, limiting the possibility of foreseeing other spillover events with pandemic potential. Here we propose an evolutionary model based on the thorough dissection of SARS-CoV-2 and RaTG13 – the closest bat relative – spike dynamics, kinetics and binding to ACE2. Our results indicate that both spikes share nearly identical, high affinities for Rhinolophus affinis bat and human ACE2, pointing out to negligible species barriers directly related to receptor binding. Also, SARS-CoV-2 spike shows a higher degree of dynamics and kinetics optimization that favors ACE2 engagement. Therefore, we devise an affinity-independent evolutionary process that likely took place in R. affinis bats and limits the eventual involvement of other animal species in initiating the pandemic to the role of vector.

The COVID-19 pandemic caused by the β-coronavirus SARS-CoV-2 has made the development of safe and effective vaccines a critical global priority. To date, four vaccines have already been approved by European and American authorities for preventing COVID-19 but the development of additional vaccine platforms with improved supply and logistics profiles remains a pressing need. Here we report the preclinical evaluation of a novel COVID-19 vaccine candidate based on the electroporation of engineered, synthetic cDNA encoding a viral antigen in the skeletal muscle, a technology previously utilized for cancer vaccines. We constructed a set of prototype DNA vaccines expressing various forms of the SARS-CoV-2 Spike (S) protein and assessed their immunogenicity in animal models. Among them, COVID-eVax – a DNA plasmid encoding a secreted monomeric form of SARS-CoV-2 S protein RBD – induced the most potent anti-SARS-CoV-2 neutralizing antibody responses (including against the current most common variants of concern) and a robust T cell response. Upon challenge with SARS-CoV-2, immunized K18-hACE2 transgenic mice showed reduced weight loss, improved pulmonary function and significantly lower viral replication in the lungs and brain. COVID-eVax conferred significant protection to ferrets upon SARS-CoV-2 challenge. In summary, this study identifies COVID-eVax as an ideal COVID-19 vaccine candidate suitable for clinical development. Accordingly, a combined phase I-II trial has recently started in Italy.

SummaryThe humoral arm of innate immunity includes diverse molecules with antibody-like functions, some of which serve as disease severity biomarkers in COVID-19. The present study was designed to conduct a systematic investigation of the interaction of humoral fluid phase pattern recognition molecules (PRM) with SARS-CoV-2. Out of 10 PRM tested, the long pentraxin PTX3 and Mannose Binding Lectin (MBL) bound the viral Nucleoprotein and Spike, respectively. MBL bound trimeric Spike, including that of variants of concern, in a glycan- dependent way and inhibited SARS-CoV-2 in threein vitromodels. Moreover, upon binding to Spike, MBL activated the lectin pathway of complement activation. Genetic polymorphisms at the MBL locus were associated with disease severity. These results suggest that selected humoral fluid phase PRM can play an important role in resistance to, and pathogenesis of, COVID-19, a finding with translational implications.

SummaryThe COVID-19 outbreak driven by SARS-CoV-2 has caused more than 2.5 million deaths globally, with the most severe cases characterized by over-exuberant production of immune-mediators, the nature of which is not fully understood. Interferons of the type I (IFN-I) or type III (IFN-III) families are potent antivirals, but their role in COVID-19 remains debated. Our analysis of gene and protein expression along the respiratory tract shows that IFNs, especially IFN-III, are over-represented in the lower airways of patients with severe COVID-19, while high levels of IFN-III, and to a lesser extent IFN-I, characterize the upper airways of patients with high viral burden but reduced disease risk or severity; also, IFN expression varies with abundance of the cell types that produce them. Our data point to a dynamic process of inter- and intra-family production of IFNs in COVID-19, and suggest that IFNs play opposing roles at distinct anatomical sites.

Growing evidence suggests that conventional dendritic cells (cDCs) undergo aberrant maturation in COVID-19 and this negatively affects T cell activation. The presence of functional effector T cells in mild patients and dysfunctional T cells in severely ill patients suggests that adequate T cell responses are needed to limit disease severity. Therefore, understanding how cDCs cope with SARS-CoV-2 infections can help elucidate the mechanism of generation of protective immune responses. Here, we report that cDC2 subtypes exhibit similar infection-induced gene signatures with the up-regulation of interferon-stimulated genes and IL-6 signaling pathways. The main difference observed between DC2s and DC3s is the up-regulation of anti-apoptotic genes in DC3s, which explains their accumulation during infection. Furthermore, comparing cDCs between severe and mild patients, we find in the former a profound down-regulation of genes encoding molecules involved in antigen presentation, such as major histocompatibility complex class II (MHCII) molecules, β2 microglobulin, TAP and costimulatory proteins, while an opposite trend is observed for proinflammatory molecules, such as complement and coagulation factors. Therefore, as the severity of the disease increases, cDC2s enhance their inflammatory properties and lose their main function, which is the antigen presentation capacity. In vitro, direct exposure of cDC2s to the virus recapitulates the type of activation observed in vivo. Our findings provide evidence that SARS-CoV-2 can interact directly with cDC2s and, by inducing the down-regulation of crucial molecules required for T cell activation, implements an efficient immune escape mechanism that correlates with disease severity.

Several viruses target the human respiratory tract, causing different clinical manifestations spanning from mild upper airway involvement to life-threatening acute respiratory distress syndrome (ARDS). As dramatically evident in the ongoing SARS-CoV-2 pandemic, the clinical picture is not always easily predictable due to the combined effect of direct viral and indirect patient-specific immune-mediated damage., SUMMARY Several viruses target the human respiratory tract, causing different clinical manifestations spanning from mild upper airway involvement to life-threatening acute respiratory distress syndrome (ARDS). As dramatically evident in the ongoing SARS-CoV-2 pandemic, the clinical picture is not always easily predictable due to the combined effect of direct viral and indirect patient-specific immune-mediated damage. In this review, we discuss the main RNA (orthomyxoviruses, paramyxoviruses, and coronaviruses) and DNA (adenoviruses, herpesviruses, and bocaviruses) viruses with respiratory tropism and their mechanisms of direct and indirect cell damage. We analyze the thin line existing between a protective immune response, capable of limiting viral replication, and an unbalanced, dysregulated immune activation often leading to the most severe complication. Our comprehension of the molecular mechanisms involved is increasing and this should pave the way for the development and clinical use of new tailored immune-based antiviral strategies.

SARS-CoV-2 spike is evolving to maximize transmissibility and evade the humoral response. The massive genomic sequencing of SARS-CoV-2 isolates has led to the identification of single-point mutations and deletions, often having the recurrence of hotspots, associated with advantageous phenotypes. We report the isolation and molecular characterization of a SARS-CoV-2 strain, belonging to a lineage (C.36) not previously associated with concerning traits, which shows decreased susceptibility to vaccine sera neutralization.

Background Platelet activation and thrombotic events characterizes COVID‐19. Objectives To characterize platelet activation and determine if SARS‐CoV‐2 induces platelet activation. Patients/Methods We investigated platelet activation in 119 COVID‐19 patients at admission in a university hospital in Milan, Italy, between March 18 and May 5, 2020. Sixty‐nine subjects (36 healthy donors, 26 patients with coronary artery disease, coronary artery disease, and seven patients with sepsis) served as controls. Results COVID‐19 patients had activated platelets, as assessed by the expression and distribution of HMGB1 and von Willebrand factor, and by the accumulation of platelet‐derived (plt) extracellular vesicles (EVs) and HMGB1+ plt‐EVs in the plasma. P‐selectin upregulation was not detectable on the platelet surface in a fraction of patients (55%) and the concentration of soluble P‐selectin in the plasma was conversely increased. The plasma concentration of HMGB1+ plt‐EVs of patients at hospital admission remained in a multivariate analysis an independent predictor of the clinical outcome, as assessed using a 6‐point ordinal scale (from 1 = discharged to 6 = death). Platelets interacting in vitro with SARS‐CoV‐2 underwent activation, which was replicated using SARS‐CoV‐2 pseudo‐viral particles and purified recombinant SARS‐CoV‐2 spike protein S1 subunits. Human platelets express CD147, a putative coreceptor for SARS‐CoV‐2, and Spike‐dependent platelet activation, aggregation and granule release, release of soluble P‐selectin and HMGB1+ plt‐EVs abated in the presence of anti‐CD147 antibodies. Conclusions Hence, an early and intense platelet activation, which is reproduced by stimulating platelets in vitro with SARS‐CoV‐2, characterizes COVID‐19 and could contribute to the inflammatory and hemostatic manifestations of the disease.

Background The ongoing pandemic of COVID-19 has underlined the importance of adopting effective infection prevention and control (IPC) measures in hospital and community settings. UV-based technologies represent promising IPC tools: their effective application for sanitation has been extensively evaluated in the past but scant, heterogeneous and not conclusive evidence is available on their effect on SARS-CoV-2 transmission. Methods With the aim of pooling the available evidence on the efficacy of UV technologies against coronaviruses, we conducted a systematic review following PRISMA guidelines, searching Medline, Embase and Cochrane Library, and the main clinical trials’ registries (WHO ICTRP, ClinicalTrials.gov, Cochrane and EU Clinical Trial Register). Quantitative data on studies’ interventionS were summarized in tables, pooled by different coronavirus species and strain, UV source, characteristics of UV light exposure and outcomes. Findings Eighteen papers met our inclusion criteria, published between 1972 and 2020. Six focused on SARS-CoV-2, four on SARS-CoV-1, one on MERS-CoV, three on seasonal coronaviruses, and four on animal coronaviruses. All were experimental studies. Overall, despite wide heterocenicity within included studies, complete inactivation of coronaviruses on surfaces or aerosolized, including SARS-CoV-2, was reported to take a maximum exposure time of 15 minutes and to need a maximum distance from the UV emitter up to 1 meter. Conclusion Advances in UV-based technologies in the field of sanitation and their proved high virucidal potential against SARS-CoV-2 support their use for IPC in hospital and community settings and their contribution towards ending the COVID-19 pandemic. National and international guidelines are to be updated and identify parameters and conditions of use to ensure both efficacy and safety of UV technology application for effective infection prevention and control in both healthcare and non-healthcare settings.

Severe COVID-19 is characterized by overproduction of immune mediators, but the role of interferons (IFNs) of the type I (IFN-I) or type III (IFN-III) families remains debated. We scrutinized the production of IFNs along the respiratory tract of COVID-19 patients and found that high levels of IFN-III, and to a lesser extent IFN-I, characterize the upper airways of patients with high viral burden but reduced disease risk or severity. Production of specific IFN-III, but not IFN-I, members, denotes patients with a mild pathology and efficiently drives the transcription of genes that protect against SARS-CoV-2. In contrast, compared to subjects with other infectious or non-infectious lung pathologies, IFNs are over-represented in the lower airways of patients with severe COVID-19 that exhibit gene pathways associated with increased apoptosis and decreased proliferation. Our data demonstrate a dynamic production of IFNs in SARS-CoV-2-infected patients and show IFNs play opposing roles at distinct anatomical sites., An in-depth analysis of interferons in COVID-19 reveals differences in their roles based on anatomical location, viral load, age and disease severity. In the upper respiratory tract, high levels of IFN-III are protective and result in mild disease in spite of higher SARS-CoV-2 viral burden while the lower airways of patients with severe COVID-19 demonstrate elevated IFN-I and III, cell death and a reduction in interferon stimulated genes.

Growing evidence suggests that conventional dendritic cells (cDCs) undergo aberrant maturation in COVID‐19, which negatively affects T‐cell activation. The presence of effector T cells in patients with mild disease and dysfunctional T cells in severely ill patients suggests that adequate T‐cell responses limit disease severity. Understanding how cDCs cope with SARS‐CoV‐2 can help elucidate how protective immune responses are generated. Here, we report that cDC2 subtypes exhibit similar infection‐induced gene signatures, with the upregulation of interferon‐stimulated genes and interleukin (IL)‐6 signaling pathways. Furthermore, comparison of cDCs between patients with severe and mild disease showed severely ill patients to exhibit profound downregulation of genes encoding molecules involved in antigen presentation, such as MHCII, TAP, and costimulatory proteins, whereas we observed the opposite for proinflammatory molecules, such as complement and coagulation factors. Thus, as disease severity increases, cDC2s exhibit enhanced inflammatory properties and lose antigen presentation capacity. Moreover, DC3s showed upregulation of anti‐apoptotic genes and accumulated during infection. Direct exposure of cDC2s to the virus in vitro recapitulated the activation profile observed in vivo. Our findings suggest that SARS‐CoV‐2 interacts directly with cDC2s and implements an efficient immune escape mechanism that correlates with disease severity by downregulating crucial molecules required for T‐cell activation. This article is protected by copyright. All rights reserved

Hepatitis C virus (HCV) is a major causative agent of acute and chronic hepatitis. It is estimated that 400,000 people die every year from chronic HCV infection, mostly from severe liver-related diseases such as cirrhosis and liver cancer. Although HCV was discovered more than 30 years ago, an efficient prophylactic vaccine is still missing. The HCV glycoprotein complex, E1/E2, is the principal target of neutralizing antibodies (NAbs) and, thus, is an attractive antigen for B-cell vaccine design. However, the high genetic variability of the virus necessitates the identification of conserved epitopes. Moreover, the high intrinsic mutational capacity of HCV allows the virus to continually escape broadly NAbs (bNAbs), which is likely to cause issues with vaccine-resistant variants. Several studies have assessed the barrier-to-resistance of vaccine-relevant bNAbs in vivo and in vitro. Interestingly, recent studies have suggested that escape substitutions can confer antibody resistance not only by direct modification of the epitope but indirectly through allosteric effects, which can be grouped based on the breadth of these effects on antibody susceptibility. In this review, we summarize the current understanding of HCV-specific NAbs, with a special focus on vaccine-relevant bNAbs and their targets. We highlight antibody escape studies pointing out the different methodologies and the escape mutations identified thus far. Finally, we analyze the antibody escape mechanisms of envelope protein escape substitutions and polymorphisms according to the most recent evidence in the HCV field. The accumulated knowledge in identifying bNAb epitopes as well as assessing barriers to resistance and elucidating relevant escape mechanisms may prove critical in the successful development of an HCV B-cell vaccine.

Plenty of serologic tests for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) have been developed so far, thus documenting the importance of evaluating the relevant features of the immune response to this viral agent. The performance of these assays is currently under investigation. Amongst them, LIAISON® SARS‐CoV‐2 S1/S2 IgG by DiaSorin and Elecsys Anti‐SARS‐CoV‐2 cobas® by Roche are currently used by laboratory medicine hospital departments in Italy and many other countries. In the present study, we firstly compared two serologic tests on serum samples collected at two different time points from 46 laboratory‐confirmed coronavirus disease‐2019 (COVID‐19) subjects. Secondly, 85 negative serum samples collected before the SARS‐CoV‐2 pandemic were analyzed. Thirdly, possible correlations between antibody levels and the resulting neutralizing activity against a clinical isolate of SARS‐CoV‐2 were evaluated. Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased to 97.8% and 100% for samples collected after 15 days for DiaSorin and Roche tests, respectively. The specificity evaluated for the two tests ranges from 96.5% to 100%, respectively. Importantly, a poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study. These data further shed light on both potentials and possible limitations related to SARS‐CoV‐2 serology. In this context, great efforts are still necessary for investigating antibody kinetics to develop novel diagnostic algorithms. Moreover, further investigations on the role of neutralizing antibodies and their correlate of protection will be of paramount importance for the development of effective vaccines., Highlights A comparative analysis between two serologic assays for the detection of antibodies directed against SARS‐CoV‐2 was carried out on sera from subjects testing positive for SARS‐CoV‐2 nasopharyngeal swabs.Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased for samples collected after 15 days.A poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study.

Routine biochemical and hematological tests have been reported to be useful in the stratification and prognostication of pediatric and adult patients with diagnosed coronavirus disease (COVID-19), correlating with poor outcomes such as the need for mechanical ventilation or intensive care, progression to multisystem organ failure, and/or death. While these tests are already well established in most clinical laboratories, there is still debate regarding their clinical value in the management of COVID-19, particularly in pediatrics, as well as the value of composite clinical risk scores in COVID-19 prognostication. This document by the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 provides interim guidance on: (A) clinical indications for testing, (B) recommendations for test selection and interpretation, (C) considerations in test interpretation, and (D) current limitations of biochemical/hematological monitoring of COVID-19 patients. These evidence-based recommendations will provide practical guidance to clinical laboratories worldwide, underscoring the contribution of biochemical and hematological testing to our collective pandemic response.

Background: The role of microbiota in Lynch syndrome (LS) is still under debate. We compared oral and fecal microbiota of LS saliva and stool samples with normal healthy controls (NHC). Methods: Total DNA was purified from feces and saliva to amplify the V3–V4 region of the 16s rRNA gene. Sequences with a high-quality score and length >250 bp were used for taxonomic analysis with QIIME software. Results: Compared to NHC, LS fecal samples demonstrated a statistically significant increase of Bacteroidetes and Proteobacteria and a significant decrease of Firmicutes at the phylum level and of Ruminococcaceae at the family level. Moreover, LS oral samples exhibited a statistically significant increase of Veillonellaceae and Leptotrichiaceae and a statistically significant decrease of Pasteurellaceae. A beta-diversity index allowed differentiation of the two groups. Conclusions: A peculiar microbial signature is associated with LS, similar to that of sporadic colorectal cancer and Crohn’s disease. These data suggest a possible role of proinflammatory bacteria in tumor development in a condition of genetic predisposition, such as LS.

Plenty of serologic tests for SARS-CoV-2 have been developed so far, thus documenting the importance of evaluating the relevant features of the immune response to this viral agent. The performance of these assays is currently under investigation. Amongst them, LIAISON® SARS-CoV-2 S1/S2 IgG by DiaSorin and Elecsys Anti-SARS-CoV-2 cobas® by Roche are currently used by laboratory medicine hospital departments in Italy and many other countries. In the present study, we have firstly compared two serologic tests on serum samples collected at two different time points from forty-six laboratory-confirmed COVID-19 subjects. Secondly, eighty-five negative serum samples collected before the SARS-CoV-2 pandemic were analyzed. Thirdly, possible correlations between antibody levels and the resulting neutralizing activity against a clinical isolate of SARS-CoV-2 were evaluated. Results revealed that both tests are endowed with low sensitivity on the day of hospital admission, which increased to 97.8 and 100% for samples collected after 15 days for DiaSorin and Roche tests, respectively. The specificity of the two tests ranges from 96.5 to 100%, respectively. Importantly, a poor direct correlation between antibody titers and neutralizing activity levels was evidenced in the present study.

The ongoing coronavirus disease 2019 pandemic has forced the clinical and scientific community to try drug repurposing of existing antiviral agents as a quick option against severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2). Under this scenario, interferon (IFN) β-1a, whose antiviral potential is already known, and which is a drug currently used in the clinical management of multiple sclerosis, may represent as a potential candidate. In this report, we demonstrate that IFN-β-1a was highly effective in inhibiting in vitro SARS-CoV-2 replication at clinically achievable concentration when administered after virus infection., Interferon β-1a hampers severe acute respiratory syndrome–coronavirus 2 replication in a Vero E6 infection model when administered after virus infection in a dose-dependent manner. This observation could be useful in the set-up of clinical trials.

The global coronavirus disease 2019 (COVID-19) has presented major challenges for clinical laboratories, from initial diagnosis to patient monitoring and treatment. Initial response to this pandemic involved the development, production, and distribution of diagnostic molecular assays at an unprecedented rate, leading to minimal validation requirements and concerns regarding their diagnostic accuracy in clinical settings. In addition to molecular testing, serological assays to detect antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are now becoming available from numerous diagnostic manufacturers. In both cases, the lack of peer-reviewed data and regulatory oversight, combined with general misconceptions regarding their appropriate use, have highlighted the importance of laboratory professionals in robustly validating and evaluating these assays for appropriate clinical use. The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 has been established to synthesize up-to-date information on the epidemiology, pathogenesis, and laboratory diagnosis and monitoring of COVID-19, as well as to develop practical recommendations on the use of molecular, serological, and biochemical tests in disease diagnosis and management. This review summarizes the latest evidence and status of molecular, serological, and biochemical testing in COVID-19 and highlights some key considerations for clinical laboratories operating to support the global fight against this ongoing pandemic. Confidently this consolidated information provides a useful resource to laboratories and a reminder of the laboratory’s critical role as the world battles this unprecedented crisis.

Objectives The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Task Force on COVID-19 conducted a global survey to understand how biochemistry laboratories manage the operational challenges during the coronavirus disease 2019 (COVID-19) pandemic. Materials and methods An electronic survey was distributed globally to record the operational considerations to mitigate biosafety risks in the laboratory. Additionally, the laboratories were asked to indicate the operational challenges they faced. Results A total of 1210 valid submissions were included in this analysis. Most of the survey participants worked in hospital laboratories. Around 15% of laboratories restricted certain tests on patients with clinically suspected or confirmed COVID-19 over biosafety concerns. Just over 10% of the laboratories had to restrict their test menu or services due to resource constraints. Approximately a third of laboratories performed temperature monitoring, while two thirds of laboratories increased the frequency of disinfection. Just less than 50% of the laboratories split their teams. The greatest reported challenge faced by laboratories during the COVID-19 pandemic is securing sufficient supplies of personal protective equipment (PPE), analytical equipment, including those used at the point of care, as well as reagents, consumables and other laboratory materials. This was followed by having inadequate staff, managing their morale, anxiety and deployment. Conclusions The restriction of tests and services may have undesirable clinical consequences as clinicians are deprived of important information to deliver appropriate care to their patients. Staff rostering and biosafety concerns require longer-term solutions as they are crucial for the continued operation of the laboratory during what may well be a prolonged pandemic.

Objectives A global survey was conducted by the IFCC Task Force on COVID-19 to better understand how general biochemistry laboratories manage the pre-analytical, analytical and post-analytical processes to mitigate biohazard risks during the coronavirus disease 2019 (COVID-19) pandemic. Methods An electronic survey was developed to record the general characteristics of the laboratory, as well as the pre-analytical, analytical, post-analytical and operational practices of biochemistry laboratories that are managing clinical samples of patients with COVID-19. Results A total of 1210 submissions were included in the analysis. The majority of responses came from hospital central/core laboratories that serve hospital patient groups and handle moderate daily sample volumes. There has been a decrease in the use of pneumatic tube transport, increase in hand delivery and increase in number of layers of plastic bags for samples of patients with clinically suspected or confirmed COVID-19. Surgical face masks and gloves are the most commonly used personal protective equipment (PPE). Just >50% of the laboratories did not perform an additional decontamination step on the instrument after analysis of samples from patients with clinically suspected or confirmed COVID-19. A fifth of laboratories disallowed add-on testing on these samples. Less than a quarter of laboratories autoclaved their samples prior to disposal. Conclusions The survey responses showed wide variation in pre-analytical, analytical and post-analytical practices in terms of PPE adoption and biosafety processes. It is likely that many of the suboptimal biosafety practices are related to practical local factors, such as limited PPE availability and lack of automated instrumentation.

Interferons interfere with lung repair Interferons (IFNs) are central to antiviral immunity. Viral recognition elicits IFN production, which in turn triggers the transcription of IFN-stimulated genes (ISGs), which engage in various antiviral functions. Type I IFNs (IFN-α and IFN-β) are widely expressed and can result in immunopathology during viral infections. By contrast, type III IFN (IFN-λ) responses are primarily restricted to mucosal surfaces and are thought to confer antiviral protection without driving damaging proinflammatory responses. Accordingly, IFN-λ has been proposed as a therapeutic in coronavirus disease 2019 (COVID-19) and other such viral respiratory diseases (see the Perspective by Grajales-Reyes and Colonna). Broggi et al. report that COVID-19 patient morbidity correlates with the high expression of type I and III IFNs in the lung. Furthermore, IFN-λ secreted by dendritic cells in the lungs of mice exposed to synthetic viral RNA causes damage to the lung epithelium, which increases susceptibility to lethal bacterial superinfections. Similarly, using a mouse model of influenza infection, Major et al. found that IFN signaling (especially IFN-λ) hampers lung repair by inducing p53 and inhibiting epithelial proliferation and differentiation. Complicating this picture, Hadjadj et al. observed that peripheral blood immune cells from severe and critical COVID-19 patients have diminished type I IFN and enhanced proinflammatory interleukin-6– and tumor necrosis factor-α–fueled responses. This suggests that in contrast to local production, systemic production of IFNs may be beneficial. The results of this trio of studies suggest that the location, timing, and duration of IFN exposure are critical parameters underlying the success or failure of therapeutics for viral respiratory infections. Science , this issue p. 706 , p. 712 , p. 718 ; see also p. 626

The dependence of the host on the interaction of hundreds of extracellular proteins with the cell surface glycosaminoglycan heparan sulphate (HS) for the regulation of homeostasis is exploited by many microbial pathogens as a means of adherence and invasion. The closely related polysaccharide heparin, the widely used anticoagulant drug, which is structurally similar to HS and is a common experimental proxy, can be expected to mimic the properties of HS. Heparin prevents infection by a range of viruses if added exogenously, including S-associated coronavirus strain HSR1. Heparin prevents infection by a range of viruses if added exogenously, including S-associated coronavirus strain HSR1. Here, we show that the addition of heparin to Vero cells between 6.25 - 200 μg.ml−1, which spans the concentration of heparin in therapeutic use, and inhibits invasion by SARS-CoV-2 at between 44 and 80%. We also demonstrate that heparin binds to the Spike (S1) protein receptor binding domain and induces a conformational change, illustrated by surface plasmon resonance and circular dichroism spectroscopy studies. The structural features of heparin on which this interaction depends were investigated using a library of heparin derivatives and size-defined fragments. Binding is more strongly dependent on the presence of 2-O or 6-O sulphation, and the consequent conformational consequences in the heparin structure, than on N-sulphation. A hexasaccharide is required for conformational changes to be induced in the secondary structure that are comparable to those that arise from heparin binding. Enoxaparin, a low molecular weight clinical anticoagulant, also binds the S1 RBD protein and induces conformational change. These findings have implications for the rapid development of a first-line therapeutic by repurposing heparin as well as for next-generation, tailor-made, GAG-based antiviral agents against SARS-CoV-2 and other members of the Coronaviridae.

While the SARS-CoV-2 pandemic is hardly hitting the world, it is of extreme importance that significant in vitro observations guide the quick set up of clinical trials. In this study, we evidence that the anti-SARS-CoV2 activity of a clinically achievable hydroxychloroquine concentration is maximized only when administered before and after the infection of Vero E6 cells. This strongly suggests that only a combined prophylactic and therapeutic use of hydroxychloroquine may be effective in limiting viral replication in patients.

Comprehensive characterization of the urinary and urothelium-bound microbiomes in bladder cancer (BCa) and healthy state is essential to understand how these local microbiomes may play a role in BCa tumorigenesis and response to therapy, as well as to explain sex-based differences in BCa pathobiology. Performing 16 s rDNA microbiome analysis on 166 samples (urine and paired bladder tissues) from therapy-naive BCa patients undergoing radical cystectomy and healthy controls, we defined (1) sex-specific microbiome differences in the urine and bladder tissue, and (2) representativeness of the tissue microenvironment by the voided urinary microbiome. The genus Klebsiella was more common in the urine of female BCa patients versus healthy controls, while no clinically relevant bacteria were found differently enriched in men. In tissues, the genus Burkholderia was more abundant in the neoplastic versus the non-neoplastic tissue in both sexes, suggesting a potential role in BCa pathobiology. Lastly, we found that the urinary microbiome shares >80% of the bacterial families present in the paired bladder tissue, making the urinary microbiome a fair proxy of the tissue bacterial environment. Patient summary We identified specific bacteria present in the urine and tissues of male and female bladder cancer patients. These novel data represent a first step toward understanding the influence of the bladder microbiome on the development of bladder cancer and on the response to intravesical and systemic therapies.

Next-generation sequencing techniques have enabled identification of the microorganisms colonizing mucosal tissues. The International Congress "MicrobiotaMi 2020" (Milan, February 2020) will focus on the mechanisms of microbiota-related functions in health and disease and their clinical application.

New insights into hepatitis C virus evasion from neutralizing antibodies have important implications for vaccine development., Broad antibody sensitivity differences of hepatitis C virus (HCV) isolates and their ability to persist in the presence of neutralizing antibodies (NAbs) remain poorly understood. Here, we show that polymorphisms within glycoprotein E2, including hypervariable region 1 (HVR1) and antigenic site 412 (AS412), broadly affect NAb sensitivity by shifting global envelope protein conformation dynamics between theoretical “closed,” neutralization-resistant and “open,” neutralization-sensitive states. The conformational space of AS412 was skewed toward β-hairpin–like conformations in closed states, which also depended on HVR1, assigning function to these enigmatic E2 regions. Scavenger receptor class B, type I entry dependency of HCV was associated with NAb resistance and correlated perfectly with decreased virus propensity to interact with HCV co-receptor CD81, indicating that decreased NAb sensitivity resulted in a more complex entry pathway. This link between global E1/E2 states and functionally distinct AS412 conformations has important implications for targeting AS412 in rational HCV vaccine designs.

Background Pharmacological therapies of proven efficacy in coronavirus disease 2019 (COVID-19) are still lacking. We have identified IFNβ-1a as the most promising drug to be repurposed for COVID-19. The rationale relies on the evidence of IFNβ anti-viral activity in vitro against SARS-CoV-2 and animal models resembling SARS-CoV-2 infection and on a recent clinical trial where IFNβ was indicated as the key component of a successful therapeutic combination. Methods This is a randomized, controlled, open-label, monocentric, phase II trial (INTERCOP trial). One hundred twenty-six patients with positive swab detection of SARS-CoV-2, radiological signs of pneumonia, and mild-to-moderate disease will be randomized 2:1 to IFNβ-1a in addition to standard of care vs standard of care alone. No other anti-viral drugs will be used as part of the regimens, both in the control and the intervention arms. IFNβ-1a will be administered subcutaneously at the dose of 44 mcg (equivalent to 12 million international units) three times per week, at least 48 h apart, for a total of 2 weeks. The primary outcome is the time to negative conversion of SARS-CoV-2 nasopharyngeal swabs. Secondary outcomes include improvement or worsening in a clinical severity score measured on a 7-point ordinal scale (including transfer to intensive care unit and death), oxygen- and ventilator-free days, mortality, changes in pulmonary computed tomography severity score, hospital stay duration, reduction of viral load measured on nasopharyngeal swabs, number of serious adverse events, and changes in biochemical markers of organ dysfunction. Exploratory outcomes include blood cell counts, cytokine and inflammatory profile, peripheral mRNA expression profiles of interferon-stimulated genes, and antibodies to SARS-CoV-2 and to IFNβ-1a. INTERCOP is the first study to specifically investigate the clinical benefits of IFNβ-1a in COVID-19 patients. Discussion Potential implications of this trial are multifaceted: should the primary outcome be fulfilled and the treatment be safe, one may envisage that IFNβ-1a be used to reduce the infectivity of patients with mild-to moderate disease. In case IFNβ-1a reduced the duration of hospital stay and/or ameliorated the clinical status, it may become a cornerstone of COVID-19 treatment. Trial registration EudraCT 2020-002458-25. Registered on May 11, 2020 ClinicalTrials.gov Identifier: NCT04449380

Objectives A milder clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been anecdotally reported over the latest phase of COVID-19 pandemic in Italy. Several factors may contribute to this observation, including the effect of lockdown, social distancing, lower humidity, lower air pollution, and potential changes in the intrinsic pathogenicity of the virus. In this regard, the clinical severity of COVID-19 could be attenuated by mutations in SARS-CoV-2 genome that decrease its virulence, as well as by lower virus inocula. Methods In this pilot study, we compared the reverse transcription polymerase chain reaction (RT-PCR) amplification profile of 100 nasopharyngeal swabs consecutively collected in April, during the peak of SARS-CoV-2 epidemic, to that of 100 swabs collected using the same procedure in May. Results The mean Ct value of positive samples collected in May was significantly higher than that of samples collected in the previous period (ORF 1a/b gene: 31.85 ± 0.32 vs. 28.37 ± 0.5, pE gene: 33.76 ± 0.38 vs. 29.79 ± 0.63, p Conclusions This pilot study prompts further investigation on the correlation between SARS-CoV-2 load and different clinical manifestation of COVID-19 during different phases of the pandemic. Laboratories should consider reporting quantitative viral load data in the molecular diagnosis of SARS-CoV-2 infection.

Objective: To study the impact of asymptomatic semen infections on seminal parameters in men presenting for primary couple's infertility. Design: Cross-sectional study. Setting: Academic center. Patients: Socio-demographic, clinical, and laboratory data from 1689 infertile men were analyzed. Intervention(s): Semen analysis was based on 2010 World Health Organization reference criteria. Each patient underwent semen culture test to identify common urogenital pathogens. Infections by Mycoplasma, Ureaplasma, and Chlamydia spp. were evaluated through a real time polymerase chain reaction platform. Descriptive statistics and linear and logistic regression models were used to test the association between semen infections and clinical, seminal, and hormonal parameters. Main Outcome Measure(s): Prevalence of asymptomatic semen infection and impact of semen infection on sperm parameters. Results: Of 1689 men, 354 (21.0%) had an asymptomatic positive semen culture. Ureaplasma urealyticum (37.6%) was the most frequent single pathogen, followed by Enterobacteriaceae (any type; 24.8%), other pathogens (20.3%), Chlamydia trachomatis (3.4%) and Mycoplasma spp (3.4%). Positive semen cultures were associated with lower sperm concentrations (P

Background Vaginal and seminal microbiomes have gained increasing interest for their involvement in reproductive health and fertility. However, their role in reproductive outcome is not fully understood yet. In this study, we aimed to correlate the vaginal and the seminal microbiome of 23 couples with idiopathic infertility to the clinical pregnancy rate after intrauterine insemination (IUI). Methods Vaginal swabs and seminal fluids were collected on the day of IUI procedure and analyzed through polymerase chain reaction amplification of variable regions 3 and 4 (V3–V4) of 16S ribosomal ribonucleic acid genes and Illumina MiSeq sequencing. The taxonomic data were then correlated to IUI success. Results Idiopathic infertile women showed a different average composition of vaginal microbiome compared with control sequences, whereas for seminal counterpart no relevant differences were observed. Furthermore, among idiopathic infertile women, different patterns of Lactobacillus species dominations were observed, with a predominance either of Lactobacillus crispatus, a marker of a healthy vaginal ecosystem, or of Lactobacillus iners and Lactobacillus gasseri, associated with a more dysbiosis-prone environment. More important, considering all investigated variables, vaginal L crispatus domination was the only factor strongly associated to IUI success (P = .0002). Conclusions Our results strengthen the potential role of L crispatus in promoting a favorable environment for pregnancy and suggest that microbiome characterization could be useful, together with standard clinical and laboratory assessments, in the pre-IUI evaluation of infertile couples.

Infections are a major cause of morbidity and mortality in hematological patients. We prospectively tested a new molecular assay (Verigene®) in 79 consecutive hematological patients, with sepsis by gram-negative bacteria. A total of 82 gram-negative microorganisms were isolated by blood cultures, of which 76 cases were mono-microbial. Considering the bacteria detectable by the system, the concordance with standard blood cultures was 100%. Resistance genes were detected in 20 of the isolates and 100% were concordant with the phenotypic antibiotic resistance. Overall, this new assay correctly identified 66/82 of all the gram-negative pathogens, yielding a general sensitivity of 80.5%, and providing information on genetic antibiotic resistance in a few hours. This new molecular assay could ameliorate patient management, resulting in a more rational use of antibiotics.

A 74-year old woman presented to the emergency room with difficulties in speaking and standing. The patient was not able to answer the clinicians’ questions, but her husband explained that she had been ill with a fever and a worsening cough for the last 2 weeks and had taken a fall 2 days before

Answer: Streptococcus pneumoniae. The figure in the photo quiz shows an uncommon Gram stain of a Streptococcus pneumoniae isolate. The subcultured isolate did not grow either on blood agar (BBL Columbia agar with 5% sheep blood; Becton Dickinson) or on chocolate agar (chocolate agar-PolyViteX; bioM