Assembly of SARS-CoV-2 nucleocapsid protein with nucleic acid

The viral genome of SARS-CoV-2 is packaged by the nucleocapsid (N-)protein into ribonucleoprotein particles (RNPs), 38 ± 10 of which are contained in each virion. Their architecture has remained unclear due to the pleomorphism of RNPs, the high flexibility of N-protein intrinsically disordered regions, and highly multivalent interactions between viral RNA and N-protein binding sites in both N-terminal (NTD) and C-terminal domain (CTD). Here we explore critical interaction motifs of RNPs by applying a combination of biophysical techniques to ancestral and mutant proteins binding different nucleic acids in an in vitro assay for RNP formation, and by examining nucleocapsid protein variants in a viral assembly assay. We find that nucleic acid-bound N-protein dimers oligomerize via a recently described protein-protein interface presented by a transient helix in its long disordered linker region between NTD and CTD. The resulting hexameric complexes are stabilized by multivalent protein-nucleic acid interactions that establish crosslinks between dimeric subunits. Assemblies are stabilized by the dimeric CTD of N-protein offering more than one binding site for stem-loop RNA. Our study suggests a model for RNP assembly where N-protein scaffolding at high density on viral RNA is followed by cooperative multimerization through protein-protein interactions in the disordered linker.

Dynamics of magnetization at infinite temperature in a Heisenberg spin chain

Understanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text]. The first two moments of [Formula: see text] show superdiffusive behavior, a hallmark of KPZ universality. However, the third and fourth moments ruled out the KPZ conjecture and allow for evaluating other theories. Our results highlight the importance of studying higher moments in determining dynamic universality classes and provide insights into universal behavior in quantum systems.

A multicenter, randomized phase 2 study to establish combinations of CBP501, cisplatin and nivolumab for ≥3rd-line treatment of patients with advanced pancreatic adenocarcinoma

BACKGROUND

There is no standard of care for ≥ 3rd-line treatment of metastatic pancreatic adenocarcinoma (PDAC). CBP501 is a novel calmodulin-binding peptide that has been shown to enhance the influx of platinum agents into tumor cells and tumor immunogenicity. This study aimed to (1) confirm efficacy of CBP501/cisplatin/nivolumab for metastatic PDAC observed in a previous phase 1 study, (2) identify combinations that yield 35% 3-month progression-free survival rate (3MPFS) and (3) define the contribution of CBP501 to the effects of combination therapy.

METHODS

CBP501 16 or 25 mg/m2 (CBP(16) or CBP(25)) was combined with 60 mg/m2 cisplatin (CDDP) and 240 mg nivolumab (nivo), administered at 3-week intervals. Patients were randomized 1:1:1:1 to (1) CBP(25)/CDDP/nivo, (2) CBP(16)/CDDP/nivo, (3) CBP(25)/CDDP and (4) CDDP/nivo, with randomization stratified by ECOG PS and liver metastases. A Fleming two-stage design was used, yielding a one-sided type I error rate of 2.5% and 80% power when the true 3MPFS is 35%.

RESULTS

Among 36 patients, 3MPFS was 44.4% in arms 1 and 2, 11.1% in arm 3% and 33.3% in arm 4. Two patients achieved a partial response in arm 1 (ORR 22.2%; none in other arms). Median PFS and OS were 2.4, 2.1, 1.5 and 1.5 months and 6.3, 5.3, 3.7 and 4.9 months, respectively. Overall, all treatment combinations were well tolerated. Most treatment-related adverse events were grade 1-2.

CONCLUSIONS

The combination CBP(25)/(16)/CDDP/nivo demonstrated promising signs of efficacy and a manageable safety profile for the treatment of advanced PDAC.

CLINICAL TRIAL REGISTRATION

NCT04953962.

Stable quantum-correlated many-body states through engineered dissipation

Engineered dissipative reservoirs have the potential to steer many-body quantum systems toward correlated steady states useful for quantum simulation of high-temperature superconductivity or quantum magnetism. Using up to 49 superconducting qubits, we prepared low-energy states of the transverse-field Ising model through coupling to dissipative auxiliary qubits. In one dimension, we observed long-range quantum correlations and a ground-state fidelity of 0.86 for 18 qubits at the critical point. In two dimensions, we found mutual information that extends beyond nearest neighbors. Lastly, by coupling the system to auxiliaries emulating reservoirs with different chemical potentials, we explored transport in the quantum Heisenberg model. Our results establish engineered dissipation as a scalable alternative to unitary evolution for preparing entangled many-body states on noisy quantum processors.

Modulation of Biophysical Properties of Nucleocapsid Protein in the Mutant Spectrum of SARS-CoV-2

Genetic diversity is a hallmark of RNA viruses and the basis for their evolutionary success. Taking advantage of the uniquely large genomic database of SARS-CoV-2, we examine the impact of mutations across the spectrum of viable amino acid sequences on the biophysical phenotypes of the highly expressed and multifunctional nucleocapsid protein. We find variation in the physicochemical parameters of its extended intrinsically disordered regions (IDRs) sufficient to allow local plasticity, but also exhibiting functional constraints that similarly occur in related coronaviruses. In biophysical experiments with several N-protein species carrying mutations associated with major variants, we find that point mutations in the IDRs can have nonlocal impact and modulate thermodynamic stability, secondary structure, protein oligomeric state, particle formation, and liquid-liquid phase separation. In the Omicron variant, distant mutations in different IDRs have compensatory effects in shifting a delicate balance of interactions controlling protein assembly properties, and include the creation of a new protein-protein interaction interface in the N-terminal IDR through the defining P13L mutation. A picture emerges where genetic diversity is accompanied by significant variation in biophysical characteristics of functional N-protein species, in particular in the IDRs.

OFF episode quality of life impact scale (OFFELIA): A new measure of quality of life for off episodes in Parkinson's disease

INTRODUCTION

OFF Episodes occur in people with Parkinson's disease when their medication wears off, and motor and/or non-motor symptoms emerge. Existing measures used to assess OFF Episodes focus on the time spent in OFF Episodes through diaries or by identifying symptoms, but they are limited in their ability to capture the severity and functional impact of OFF episodes. The aim of this study was to develop and validate a new instrument, called "OFFELIA," that measures the impact of OFF episodes on the quality of life of individuals with Parkinson's disease.

METHODS

Participants completed a cross-sectional questionnaire, "Impact and Communication on OFF Periods," while enrolled in the online clinical study Fox Insights. The data collected was used to develop OFFELIA. Psychometric testing was performed on 18 candidate items using classical, exploratory factor analysis, and item response theory methods.

RESULTS

569 individuals with Parkinson's disease completed the questionnaire. All items were retained for the final measure, with 17 items aggregated into two multi-item scales (functioning and psychological well-being) and one item reported separately as it did not function well with the other items (employment). Known group comparisons based on average duration, frequency and unpredictability of OFF episodes indicated that OFFELIA subscales were more sensitive than existing generic and condition-specific measures.

CONCLUSION

Initial evidence supports the validity of OFFELIA, a new instrument that assesses the impact of OFF periods on daily life. This instrument can be used in assessing clinical therapeutic strategies targeting OFF episodes in Parkinson's disease.

Pesticides as a potential independent childhood leukemia risk factor and as a potential confounder for electromagnetic fields exposure

BACKGROUND

Both pesticides and high magnetic fields are suspected to be childhood leukemia risk factors. Pesticides are utilized at commercial plant nurseries, which sometimes occupy the areas underneath high-voltage powerlines.

OBJECTIVES

To evaluate whether potential pesticide exposures (intended use, chemical class, active ingredient) utilized at plant nurseries act as an independent childhood leukemia risk factor or as a confounder for proximity to, or magnetic fields exposure from, high-voltage powerlines.

METHODS

We conducted a state-wide records-based case-control study for California with 5788 childhood leukemia cases and 5788 controls that examined specific pesticide use, magnetic field exposures and distances to both powerlines and plant nurseries. Exposure assessment incorporated geographic information systems, aerial satellite images, and other historical information.

RESULTS

Childhood leukemia risk was potentially elevated for several active pesticide ingredients: permethrin (odds ratio (OR) 1.49, 95% confidence interval (CI) (0.83-2.67), chlorpyrifos (OR 1.29, 95% CI 0.89-1.87), dimethoate (OR 1.79, 95% CI 0.85-3.76), mancozeb (OR 1.41, 95% CI 0.85-2.33), oxyfluorfen (OR 1.41, 95% CI 0.75-2.66), oryzalin (OR 1.60, 95% CI 0.97-2.63), and pendimethalin (OR 1.82, 95% CI 0.81-2.25). Rodenticide (OR 1.42, 95% CI 0.78-2.56) and molluscicide (OR 1.22, 95% CI 0.82-1.81) exposure also presented potentially elevated childhood leukemia risks. Childhood leukemia associations with calculated fields or powerline proximity did not materially change after adjusting for pesticide exposure. Childhood leukemia risks with powerline proximity remained similar when pesticide exposures were excluded.

DISCUSSION

Pesticide exposure may be an independent childhood leukemia risk factor. Childhood leukemia risks for powerline proximity and magnetic fields exposure were not explained by pesticide exposure.

Assembly reactions of SARS-CoV-2 nucleocapsid protein with nucleic acid

The viral genome of SARS-CoV-2 is packaged by the nucleocapsid (N-) protein into ribonucleoprotein particles (RNPs), 38±10 of which are contained in each virion. Their architecture has remained unclear due to the pleomorphism of RNPs, the high flexibility of N-protein intrinsically disordered regions, and highly multivalent interactions between viral RNA and N-protein binding sites in both N-terminal (NTD) and C-terminal domain (CTD). Here we explore critical interaction motifs of RNPs by applying a combination of biophysical techniques to mutant proteins binding different nucleic acids in an in vitro assay for RNP formation, and by examining mutant proteins in a viral assembly assay. We find that nucleic acid-bound N-protein dimers oligomerize via a recently described protein-protein interface presented by a transient helix in its long disordered linker region between NTD and CTD. The resulting hexameric complexes are stabilized by multi-valent protein-nucleic acid interactions that establish crosslinks between dimeric subunits. Assemblies are stabilized by the dimeric CTD of N-protein offering more than one binding site for stem-loop RNA. Our study suggests a model for RNP assembly where N-protein scaffolding at high density on viral RNA is followed by cooperative multimerization through protein-protein interactions in the disordered linker.

Anti-thrombotics and major adverse cardiovascular events in anti-phospholipid syndrome: a cross-sectional study using the 2016-2018 National Inpatient Sample database

OBJECTIVE

This study assessed the relationship between anti-thrombotics and major adverse cardiovascular events (MACE) in patients with anti-phospholipid syndrome (APS).

METHOD

We included 13 947 subjects with APS from the National (Nationwide) Inpatient Sample (NIS) database for 2016-2018, and collected relevant covariates and demographic data using ICD-10 codes. Our two primary outcomes were MACE and death. We performed multivariate logistic regression analysis to assess the impact of various anti-thrombotic regimens on MACE/death in our primary cohort and high-risk subgroups.

RESULTS

Patients on anti-coagulants had significantly reduced odds of MACE [odds ratio (OR) 0.68, 95% confidence interval (CI) 0.62-0.76, p < 0.001] as well as each of its subcomponents. Those not on any anti-coagulants had significantly increased odds of MACE (OR 1.47, 95% CI 1.24-1.72, p < 0.001). No significant association was found between anti-platelet use and the odds of MACE (p > 0.05). Patients on anti-coagulants were the only class that appeared to have a mortality benefit with reduced odds for death (OR 0.64, 95% CI 0.49-0.84, p = 0.001). In the subgroups at higher risk for MACE (those with atrial fibrillation and thrombocytopenia), full anti-coagulation therapy was also the only anti-thrombotic class that significantly affected the odds of MACE, with a protective effect on MACE, but had no mortality benefit.

CONCLUSION

Patients with APS are most likely to benefit from anti-coagulant therapy in reducing MACE. Furthermore, anti-platelets alone or in combination with anti-coagulants are probably not beneficial in MACE reduction and may even increase risk.

Quantification of rare earth elements in Australian and imported rice samples from different origins using ICP-MS

Rare earth elements (REEs) are also known as lanthanides and are comprised of seventeen elements including lanthanum to lutetium in the periodic table. Despite their increased utilization, little attention is given to them as emerging environmental contaminants and their associated health risks. The concentration of these elements in urban and agronomic soil may trigger bioaccumulation in plants and may enter the food chain. Also, the consumption of fertilizers in agricultural practices on a larger scale is a significant challenge. The REEs enriched fertilizers are a risk factor for contamination in soil and food. However, there is very limited data in the literature regarding the occurrence of these elements in a staple food such as rice. Thus, this study is aimed at quantification of rare earth elements in Australian and imported rice samples from different countries by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The developed analytical method was validated by using two certified reference materials (CRMs) for precision and accuracy. The method was applied for analysing rice samples (including polished, brown, and parboiled) imported from different countries and sourced locally and consumed by the Australian population. The average concentration of REEs in Australian, Thailand and Vietnamese rice samples were quantified as 0.013-2.974 μg/kg, 0.012-3.113 μg/kg, 0.009-0.919 μg/kg respectively and were lower than other countries. The highest average concentrations of REEs were found in Pakistan (0.299-128.2 μg/kg), India (0.063-20.574 μg/kg), and Sri Lankan (0.022-11.522 μg/kg) rice samples imported to Australia. Scandium and yttrium were found in the range of 107.463-85.961 μg/kg. The pattern of Light rare earth elements (LREE) was more abundant than heavy rare earth elements (HREE). This study did not include field experiments to find the translocation factors of REEs from soil to different parts of plant bodies, thus cannot establish the correlation between fertilizers and REEs concentration in rice grains. However, this study presented the general interpretation of REEs quantification in rice grains from different Countries. The outcome of this study includes filling the subsequent knowledge gaps in analysing REEs in rice. This study indicated the need to establish a monitoring program for this type of staple cereals, aiming at promoting public health.

Association between allergic rhinitis and despair, suicidal ideation, and suicide attempts in Korean adolescents: a nationally representative study of one million adolescents

OBJECTIVE

There is a lack of studies establishing the association between allergic rhinitis (AR) and despair, suicidal thinking, and suicide attempts in adolescents and children at a population level. This study aimed to investigate whether there are associations between allergic rhinitis and despair, suicidal thinking, and suicide attempts.

PATIENTS AND METHODS

The study utilized data from middle through high school adolescents from 2005-2021 who enrolled in the Korea Youth Risk Behavior Web-based Survey (KYRBS; 1,067,169). We assessed despair, suicidal thinking, and suicide attempts in the context of both non-atopic and atopic AR. Multivariable analysis was used to determine the association of variables.

RESULTS

The prevalence of allergic rhinitis was 28.0%. 1,067,169 enrolled participants were included in the final analysis. There were 299,468 individuals with allergic rhinitis and 767,701 without. In the context of AR, adolescents were more likely to have despair [adjusted odds ratio (aOR), 1.16; 95% CI, 1.15-1.17], suicidal thoughts (aOR, 1.12; 95% CI, 1.11-1.13 for model 2), and suicide attempts (aOR, 1.13; 95% CI, 1.10-1.15 for model 2). Individuals with atopic AR were more likely in almost all measures to have despair, suicidal thinking, and suicide attempts than individuals with non-atopic AR. Females with AR were more likely to have suicide attempts and middle school students were more likely to have despair, suicidal thoughts, and suicide attempts.

CONCLUSIONS

The results of this study warrant future studies investigating why AR is so closely associated with despair, suicidal ideation, and suicide attempts, with the goal of establishing suicide prevention strategies as well as improving overall mental health for adolescents.

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory1: by collapsing the wavefunction, it can enable phenomena such as teleportation2 and thereby alter the 'arrow of time' that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time3-10 that go beyond the established paradigms for characterizing phases, either in or out of equilibrium11-13. For present-day noisy intermediate-scale quantum (NISQ) processors14, the experimental realization of such physics can be problematic because of hardware limitations and the stochastic nature of quantum measurement. Here we address these experimental challenges and study measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping9,15-17 to avoid mid-circuit measurement and access different manifestations of the underlying phases, from entanglement scaling3,4 to measurement-induced teleportation18. We obtain finite-sized signatures of a phase transition with a decoding protocol that correlates the experimental measurement with classical simulation data. The phases display remarkably different sensitivity to noise, and we use this disparity to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realizing measurement-induced physics at scales that are at the limits of current NISQ processors.

First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment

The LUX-ZEPLIN experiment is a dark matter detector centered on a dual-phase xenon time projection chamber operating at the Sanford Underground Research Facility in Lead, South Dakota, USA. This Letter reports results from LUX-ZEPLIN's first search for weakly interacting massive particles (WIMPs) with an exposure of 60 live days using a fiducial mass of 5.5 t. A profile-likelihood ratio analysis shows the data to be consistent with a background-only hypothesis, setting new limits on spin-independent WIMP-nucleon, spin-dependent WIMP-neutron, and spin-dependent WIMP-proton cross sections for WIMP masses above 9  GeV/c^{2}. The most stringent limit is set for spin-independent scattering at 36  GeV/c^{2}, rejecting cross sections above 9.2×10^{-48}  cm at the 90% confidence level.

Non-Abelian braiding of graph vertices in a superconducting processor

Indistinguishability of particles is a fundamental principle of quantum mechanics¹. For all elementary and quasiparticles observed to date-including fermions, bosons and Abelian anyons-this principle guarantees that the braiding of identical particles leaves the system unchanged^2,3. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions^4-8. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well-developed mathematical description of non-Abelian anyons and numerous theoretical proposals^9-22, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. Whereas efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasiparticles, superconducting quantum processors allow for directly manipulating the many-body wavefunction by means of unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons^9,10, we implement a generalized stabilizer code and unitary protocol²³ to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of using the anyons for quantum computation and use braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and, through the future inclusion of error correction to achieve topological protection, could open a path towards fault-tolerant quantum computing.

A conserved oligomerization domain in the disordered linker of coronavirus nucleocapsid proteins

The nucleocapsid (N-)protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a key role in viral assembly and scaffolding of the viral RNA. It promotes liquid-liquid phase separation (LLPS), forming dense droplets that support the assembly of ribonucleoprotein particles with as-of-yet unknown macromolecular architecture. Combining biophysical experiments, molecular dynamics simulations, and analysis of the mutational landscape, we describe a heretofore unknown oligomerization site that contributes to LLPS, is required for the assembly of higher-order protein-nucleic acid complexes, and is coupled to large-scale conformational changes of N-protein upon nucleic acid binding. The self-association interface is located in a leucine-rich sequence of the intrinsically disordered linker between N-protein folded domains and formed by transient helices assembling into trimeric coiled-coils. Critical residues stabilizing hydrophobic and electrostatic interactions between adjacent helices are highly protected against mutations in viable SARS-CoV-2 genomes, and the oligomerization motif is conserved across related coronaviruses, thus presenting a target for antiviral therapeutics.

Soft Tissue Sarcomas in Octogenarian Patients: Are Treatment Options and Oncological Outcomes Different? A SEER Retrospective Study

AIMS

As the US population continues to age, oncological strategies and outcomes for soft tissue sarcomas (STSs) should continue to be examined for varying age groups. The aim of this study was analyse and compare treatment strategies and oncological outcomes for octogenarian patients with STSs.

MATERIALS AND METHODS

Data from the Surveillance, Epidemiology and End Results (SEER) national database were used. Varying treatment modalities were studied when utilised for specific tumour staging with respect to the eighth edition of the American Joint Committee on Cancer.

RESULTS

In total, 24 666 patients were included for analysis, where 3341 (14%) were 80 years old or older. The octogenarian group was diagnosed with more advanced disease (stages II-IV), relative to their younger counterparts (85% versus 75%, P < 0.001). However, a smaller proportion of the older patients underwent surgical resection (74% versus 86%, P < 0.001). Likewise, the octogenarians received less chemotherapy (4% versus 21%, P < 0.001) and radiotherapy (29% versus 42%, P = 0.010). Surgical resection and chemotherapy significantly improved overall survival for those older patients with stage II STS, whereas surgical resection and radiotherapy improved mortality in this cohort with both stage III and IV STS. Overall survival at 1 and 5 years of follow-up was lower within the octogenarian group compared with the younger group (1 year: 68% versus 88%, P < 0.001 and 5 years: 7% versus 58%, P < 0.001).

CONCLUSIONS

Octogenarian patients, in most cases, are diagnosed with stage III or metastatic disease. Surgical resection of the primary tumour was beneficial in both age cohorts, with radiotherapy correlating to better overall survival when used in those patients with higher stage STS. Chemotherapy was associated with better mortality in the younger cohort with respect to tumour stage. The octogenarian overall survival at 1 and 5 years was lower than for younger patients.

A Scoping Review of Adverse Incidents Research in Aged Care Homes: Learnings, Gaps, and Challenges

Background: Adverse incidents are well studied within acute care settings, less so within aged care homes. The aim of this scoping review was to define the types of adverse incidents studied in aged care homes and highlight strengths, gaps, and challenges of this research. Methods: An expanded definition of adverse incidents including physical, social, and environmental impacts was used in a scoping review based on the PRISMA Extension for Scoping Reviews Checklist. MEDLINE, CINAHL, and EBSCOhost were searched for English language, peer-reviewed studies conducted in aged care home settings between 2000 and 2020. Forty six articles across 12 countries were identified, charted, and analyzed using descriptive statistics and narrative summary methods. Results: Quantitative studies (n = 42, 91%) dominated adverse incidents literature. The majority of studies focused on physical injuries (n = 29, 63%), with fewer examining personal/interpersonal (15%) and environmental factors (22%). Many studies did not describe the country's aged care system (n = 26, 56%). Only five studies (11%) included residents' voices. Discussion: This review highlights a need for greater focus on resident voices, qualitative research, and interpersonal/environmental perspectives in adverse event research in aged care homes. Addressing these gaps, future research may contribute to better understanding of adverse incidents within this setting.

Formation of robust bound states of interacting microwave photons

Systems of correlated particles appear in many fields of modern science and represent some of the most intractable computational problems in nature. The computational challenge in these systems arises when interactions become comparable to other energy scales, which makes the state of each particle depend on all other particles1. The lack of general solutions for the three-body problem and acceptable theory for strongly correlated electrons shows that our understanding of correlated systems fades when the particle number or the interaction strength increases. One of the hallmarks of interacting systems is the formation of multiparticle bound states2-9. Here we develop a high-fidelity parameterizable fSim gate and implement the periodic quantum circuit of the spin-½ XXZ model in a ring of 24 superconducting qubits. We study the propagation of these excitations and observe their bound nature for up to five photons. We devise a phase-sensitive method for constructing the few-body spectrum of the bound states and extract their pseudo-charge by introducing a synthetic flux. By introducing interactions between the ring and additional qubits, we observe an unexpected resilience of the bound states to integrability breaking. This finding goes against the idea that bound states in non-integrable systems are unstable when their energies overlap with the continuum spectrum. Our work provides experimental evidence for bound states of interacting photons and discovers their stability beyond the integrability limit.

Comparative Sensitivity of Solid-Phase Versus PEG Enhancement Assays for Detection and Identification of Red Blood Cell Antibodies

Introduction/Objective

Identifying antibodies to red blood cell (RBC) antigens is one of transfusion medicine’s most critical and challenging issues. There are 354 RBC antigens recognized by the International Society of Blood Transfusion. Accurate identification of clinically significant alloantibodies is imperative for identifying and preventing hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. We compared the performance of the tube (polyethylene glycol–indirect antiglobulin test [PEG-IAT]) and solid-phase techniques for antibody identification.

Methods/Case Report

We performed a retrospective study on all antibody screens and identifications performed between 2007–2021 at Stanford Hospital. Over this period, 631,535 antibody screens were performed predominantly using an automated solid-phase technique. Subsequent antibody identification studies were performed using manual tube testing (PEG-IAT) and automated solid-phase techniques.

Results (if a Case Study enter NA)

Antibody screening resulted in 28,316 (4.5%) positive samples with at least one antibody. Antibody identification performed on both platforms identified 50 discordant [DMH1] samples. 8 anti-Jka, 2 anti-Jkb, 1 anti-S, and 1 anti-M were detected by automatic solid-phase technique but were not detected by PEG-IAT. 20 anti-E, 6 anti-K, 2 anti-Fya, 2 anti-c , 2 anti-C, 2 anti-Fyb, 1 anti-cE[DMH2] , 1 anti-e,1 anti-M, and 1 anti-S were detected by PEG-IAT but were negative by automated solid-phase technique. Anti-E had the least sensitivity (98.99%) in the automated solid-phase technique, while anti-Jkb had the least sensitivity (98.78%) in PEG-IAT.

Conclusion

This is the first robust 15-year study comparing methodologic sensitivity to detect clinically significant alloantibodies. The incidence of discordant results between the PEG-IAT and solid-phase technique was low. Among discordant samples, anti-Jka was commonly detected by solid-phase but not by PEG-IAT. In contrast, anti-E was commonly detected by PEG-IAT but not by the solid phase.

Workflow Improvement after Implementing Remote Blood Allocation Devices at an Academic Medical Center Blood Bank

Introduction/Objective

Patients with hematological cancer routinely receive red blood cell (RBC) transfusions in the outpatient infusion clinical setting as part of their clinical therapy. Typically, RBCs are delivered to the outpatient infusion clinic via the pneumatic tube (P-tube). However, due to the recent expansion of the hospital footprint and the new location of the transfusion services, the P-tube encountered challenges that impacted the reliability of the delivery of RBC, which can delay patient care and affect patient satisfaction. This study’s purpose is to evaluate the pre-and post-implementation of the Haemobank-20 (HB20), remote blood storage and dispensing device, by reviewing the turn-around time (TAT) and the number of orders fulfilled outside of the transfusion service.

Methods/Case Report

Blood products are stocked to the HB in the infusion center. An electronic transfusion schedule is reviewed the night before scheduled transfusions to ensure appropriate inventory. When a patient is ready for the transfusion, the clinical nurse will use the device to retrieve blood products for the patient from the HB20. The average timed delivery time from the transfusion service to the outpatient infusion center is about 11 minutes. Data was retrospectively gathered from a 10-month interval before and after HB20 implementation to evaluate the number of orders fulfilled by the HB20.

Results (if a Case Study enter NA)

The HB has helped maintain nurse-to-patient ratios, reduced traffic at the blood bank issue window, and significantly sped up the turnaround time of RBCs from 11 minutes to less than 60 seconds. Before HB implementation, staff at the blood bank received 2853 units of RBCs through the blood bank window. This has been decreased by 61.2 percent to 1136 RBCs.

Conclusion

Implementing the Haemobank-20 in the outpatient infusion center has successfully reduced the turnaround time and the workload within the Transfusion Services. The current results study demonstrate that the remote blood-release system is safe and helpful in improving the efficiency of blood issue for patients in remote outpatient locations.

Localized recharge processes in the NE Mekong Delta and implications for groundwater quality

Understanding recharge in the Mekong Delta is critical for the delta's groundwater resources, and requires the investigation of recharge processes at the local scale. In this study of the north eastern area of the Mekong Delta, time-series of environmental tracer data (δ¹⁸O, δ²H, major ions and ³H) and markers of rural pollution (NH₄ and NO₃) were used to highlight localized recharge and impacts on groundwater quality. Results highlighted new hydrological insights into recharge processes, including that the Pleistocene aquifer receives recent recharge (< 60 years), predominantly during high rainfall months (> 100 mm/month). However, due to shallow clay layers there are significant spatial variations in these recharge processes, which were observed in the seasonal fluctuation of groundwater δ¹⁸O values in groundwater. Wet season δ¹⁸O changes ranged from below analytical uncertainty (≤ 0.10 ‰) to up to 0.56 ‰, and the calculated fraction of rainfall contribution to the aquifer is ≤5 % to 16 %. Rainfall recharge via the acrisol soils results in low groundwater EC (20-55 μS/cm), acidic groundwater (pH 3.6-5.6), and may also have resulted in the low groundwater NO₃ concentrations (≤ 5.3 mg NO₃/L) at many sites due to adsorption, therefore delaying not reducing NO₃ contamination. Site specific variations in nitrogen processes includes increased NO₃ (to 29.7 mg/L) from fertiliser transfers or nitrification, and increased NH₄ (to 1.4 mg/L) likely due to the recharge of irrigation waters. Unlike other recharge areas across the northern Mekong Delta, this north-eastern region provides a groundwater resource unaffected by arsenic contamination. Therefore, these results should inform on priority areas for protection from further contamination by rural anthropogenic activities.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

Commercial outdoor plant nurseries as a confounder for electromagnetic fields and childhood leukemia risk

BACKGROUND

Close residential proximity to powerlines and high magnetic fields exposure may be associated with elevated childhood leukemia risks as reported by prior studies and pooled analyses. Magnetic fields exposure from high-voltage powerlines is associated with proximity to these powerlines and consequently with any factor varying with distance. Areas underneath powerlines in California may be sites for commercial plant nurseries that can use pesticides, a potential childhood leukemia risk factor.

OBJECTIVES

Assess if potential pesticide exposure from commercial plant nurseries is a confounder or interacts with proximity or magnetic fields exposure from high-voltage powerlines to increase childhood leukemia risk.

METHODS

A comprehensive childhood leukemia record-based case-control study with 5788 cases and 5788 controls (born and diagnosed in California, 1986-2008) was conducted. Pesticide, powerline, and magnetic field exposure assessment utilized models that incorporated geographical information systems, aerial satellite images, site visits and other historical information.

RESULTS

The relationship for calculated fields with childhood leukemia (odds ratio (OR) 1.51, 95% confidence interval (CI) 0.70-3.23) slightly attenuated when controlling for nursery proximity (OR 1.43, 95% CI 0.65-3.16) or restricting analysis to subjects living far (>300 m) from nurseries (OR 1.43, 95% CI 0.79-2.60). A similar association pattern was observed between distance to high-voltage powerlines and childhood leukemia. The association between nursery proximity and childhood leukemia was unchanged or only slightly attenuated when controlling for calculated fields or powerline distance; ORs remained above 2 when excluding subjects with high calculated fields or close powerline proximity (OR 2.16, 95% CI 0.82-5.67 and OR 2.15, 95% CI 0.82-5.64, respectively). The observed relationships were robust to different time periods, reference categories, and cut points.

DISCUSSION

Close residential proximity to nurseries is suggested as an independent childhood leukemia risk factor. Our results do not support plant nurseries as an explanation for observed childhood leukemia risks for powerline proximity and magnetic fields exposure, although small numbers of subjects concurrently exposed to high magnetic fields, close powerline proximity and plant nurseries limited our ability to fully assess potential confounding.

P-580 Cumulative live birth rate of oocyte in-vitro maturation with a pre-maturation step in women with polycystic ovary syndrome or high antral follicle count

Study question

What is the cumulative live birth rate (CLBR) at 24 months of women undergoing oocyte in vitro maturation (IVM) a with pre-maturation step (CAPA-IVM)?

Summary answer

The CLBR at 24 months with CAPA-IVM was 38.2%.

What is known already

IVM with a pre-maturation step, known as capacitation IVM (CAPA-IVM) improves the competence of oocytes matured in-vitro by sustaining meiotic arrest to allow the synchronization of cytoplasmic and genetic maturation of the oocytes. Results from a randomized controlled trial showed that CAPA-IVM resulted in a live birth rate after the first transfer of 35.2% which was non-inferior to IVF. There is a lack of data on cumulative live birth following CAPA-IVM.

Study design, size, duration

A multi-center, retrospective study, performed at IVFMD, My Duc Hospital and IVFMD Phu Nhuan, My Duc Phu Nhuan Hospital from 1 January 2017 to 31 December 2019.

Participants/materials, setting, methods

All women with polycystic ovary syndrome (PCOS) or high antral follicle count (AFC) treated with a CAPA-IVM cycle were recruited to the study. All embryos were frozen at day 3. Cumulative live birth was difined as at least one live birth resulting from initiated CAPA-IVM cycle. If the women did not return for embryo transfer, outcomes were followed up until 24 months from aspiration day. Logistic regression was performed to assess which factors predicted CLBR.

Main results and the role of chance

Between 1 January 2019 and 31 December 2019, there were 374 eligible women included in the study, among them, 368 patients had embryos for transfer (98.4%) and six patients had no embryo for transfer (1.6%). A total of 496 frozen embryo transfer (FET) cycles from 368 patients were performed. Mean age and body max index (BMI) were 29.5±3.21 years and 22.3±3.09, respectively. The maturation rate was 63.2%. The median number of embryos was 4.0 [2.00; 6.00]. The cumulative clinical pregnancy rate was 60.4%, cumulative ongoing pregnancy rate was 51.6%. At 24 months after starting the treatment, the CLBR of CAPA-IVM was 38.2%. Multivariate analysis showed that patient age and number of metaphase II oocytes were the predictive factors for cumulative live birth after CAPA-IVM.

Limitations, reasons for caution

The study limitation derives from its retrospective nature. The generalizability of the study may be limited due to the single ethnicity group.

Wider implications of the findings

In patients with PCOS or high AFC, CAPA-IVM was viable and resulted in acceptable CLBR. CAPA-IVM may be the first-line treatment for women with PCOS or high AFC requiring assisted reproduction.

Trial registration number

not applicable

POS0658 TUMOR NECROSIS FACTOR BLOCKERS INDUCED SARCOIDOSIS: DESCRIPTION OF 31 CASES FROM THE FRENCH PHARMACOVIGILANCE DATABASE

Background

Development of Tumor Necrosis Factor blockers (TNFb) whose drug class has several mechanistic and pharmacologic sub-classes, have improved the management of autoimmune and inflammatory diseases, including sarcoidosis. With their increasing use, paradoxical reactions are described and one of the most frequent is sarcoidosis. However, the description of TNFb-induced sarcoidosis (TIS) remains poor, because reported in few and only short case-series.

Objectives

We aimed to better describe the clinical spectrum of TIS, and the differential involvement of TNFb sub-classes.

Methods

French pharmacovigilance database was used to collect data on TIS, excluding patients with previous idiopathic sarcoidosis. Statistical analyses were performed using the Mann-Whitney test for quantitative data and Fisher test for qualitative data. A p value < 0.05 was considered statistically significant.

Results

Data were obtained from 2002 to 2019 for infliximab, adalimumab, golimumab, certolizumab and etanercept. Thirty-one TIS patients were collected from the database, including 12 women (38.7%). In most cases, TNFb was introduced for ankylosing spondylitis (58%), psoriasis (19.3%) or rheumatoid arthritis (16.1%). Median age at TIS occurrence was 54 [43.5; 61.5] years, with a median time to onset of 24 [6.0; 72.0] months. The most frequent involved TNFb was etanercept (n=21, 67.8%). The two mains clinical TIS manifestations were lymph node (n=27, 87.1%) and lung involvement (n=16, 51.6%). The culprit drug was discontinued in 26 (84%) patients, and a double-barreled inflammatory gun to control both initial and induced disorders was proposed in 19 of them (90.5 %), mostly glucocorticoids (n=13, 68.4%) alone or combined with methotrexate (n=3, 15,8%). Among the 14 patients with the available data, the TIS had completely resolved in 11 (78.6%); for all these lasts, the TNFb was discontinued. No significant differences were observed between the TNFb sub-classes of monoclonal antibodies or fusion proteins, regarding clinical presentation, median time to onset or outcome.

Conclusion

This second largest case-series shows that TIS are mostly encountered with etanercept, but without any difference in clinical or prognostic implications with the other TNFb-subclasses.

References

[1]Aggarwal BB, Gupta SC, Kim JH. Historical perspectives on tumor necrosis factor and its superfamily: 25 years later, a golden journey. Blood. 2012 Jan 19;119(3):651–65.

[2]Cohen Aubart F, Lhote R, Amoura A, Valeyre D, Haroche J, Amoura Z, et al. Drug-induced sarcoidosis: an overview of the WHO pharmacovigilance database. J Intern Med. 2019 Oct 15;

[3]Daïen CI, Monnier A, Claudepierre P, Constantin A, Eschard J-P, Houvenagel E, et al. Sarcoid-like granulomatosis in patients treated with tumor necrosis factor blockers: 10 cases. Rheumatology (Oxford). 2009 Aug;48(8):883–6.

[4]Javot L, Tala S, Scala-Bertola J, Massy N, Trenque T, Baldin B, et al. [Sarcoïdosis and anti-TNF: a paradoxical class effect? Analysis of the French Pharmacovigilance system database and literature review]. Therapie. 2011 Apr;66(2):149–54.

[5]Massara A, Cavazzini L, La Corte R, Trotta F. Sarcoidosis appearing during anti-tumor necrosis factor alpha therapy: a new ‘class effect’ paradoxical phenomenon. Two case reports and literature review. Semin Arthritis Rheum. 2010 Feb;39(4):313–9.

[6]Valeyre D, Prasse A, Nunes H, Uzunhan Y, Brillet P-Y, Müller-Quernheim J. Sarcoidosis. Lancet. 2014 Mar;383(9923):1155–67.

Disclosure of Interests

None declared

AB0615 Clinical impact of ceruloplasmin levels at ANCA-associated vasculitis diagnosis

Background

Myeloperoxidase (MPO) plays a major role in loss of immunological tolerance leading to tissue destruction in ANCA-associated vasculitis (AAV). Ceruloplasmin is a protein with antiproteinase and antioxidant properties that inhibits MPO activity. Whether serum level of ceruloplasmin at AAV diagnosis has an impact is unknown.

Objectives

The objective of this study was to evaluate the prognostic impact of serum level of ceruloplasmin at diagnosis in patients with granulomatosis with polyangiitis or microscopic polyangiitis.

Methods

We conducted a retrospective unicentric study at Caen University Hospital, involving consecutive adult patients with granulomatosis with polyangiitis or microscopic polyangiitis between 2010 and 2021 who had available serum at diagnosis. Data was collected using the health records.

Ceruloplasmin was measured by standardized nephelometry (normal values: 0.15 – 0.50 g/L). Patients in each subgroup (whole cohort, microscopic polyangiitis and anti-MPO patients) were divided into two groups based on the median serum level of ceruloplasmin.

We estimated survival using the Kaplan-Meier survival curve, and between-group differences were evaluated by the log-rank test. The study was approved by the local ethics committee of Caen University Hospital (n° 1947).

Results

Ninety-two patients were included, 46 (50%) granulomatosis with polyangiitis (41 anti-proteinase 3 and 5 anti-MPO) and 46 (50%) microscopic polyangiitis (45 anti-MPO and 1 anti-proteinase 3). The median level of ceruloplasmin was 0.44 g/L. No significant differences in the clinical presentation were observed between patients in the two groups (p>0.05). We observed 9 (19.6%) deaths in the low ceruloplasmin group and 5 (10.9%) in the high ceruloplasmin group (p=0.39). Vasculitis relapse occurred in 10/46 patients (22%) and 11/46 patients (24%) (p=1), renal failure leading to dialysis and/or renal transplant in 6/46 patients (13%) and 8/46 patients (17%) (p=0.77), respectively. No significant difference in survival was found (p=0.07). The same analyses were performed between the low and the high ceruloplasmin group with the microscopic polyangiitis subgroup (n=46), and no significant differences were found (p>0.05). However, within the anti-MPO subgroup (n=50), the survival was worse in the low ceruloplasmin group (p=0.03).

Conclusion

In anti-MPO AAV patients, serum level of ceruloplasmin at diagnosis seems to be associated with a significant impact on survival.

References

[1]Baskin E, et al. Ceruloplasmin levels in antineutrophil cytoplasmic antibody-positive patients. Pediatr Nephrol. 2002;17(11):917–9.

[2]Ara J, et al. Ceruloplasmin in small vessel vasculitis. Nephrol Dial Transplant. févr 1999;14(2):515-7.

isclosure of Interests: None declared

POS0425 METABOLIC ALTERATIONS IN ACTIVATED FIBROBLAST-LIKE SYNOVIOCYTES FROM NON-INFLAMED SUBJECTS - MIMICKING EARLY STAGE OF RHEUMATOID ARTHRITIS

Background

Proliferative cells, such as inflamed cells, depend on altered metabolic pathways to support their active proliferation. Synovial samples from patients with rheumatoid arthritis (RA) show reprogramming of different metabolic pathways such as glucose and glutamine metabolism [1]. However, it is unknown which metabolic pathways are altered in the early phases of RA pathogenesis, when non-inflamed fibroblast-like synoviocytes (FLS) are activated to a pro-inflammatory state. Our group has created an in-vitro cell model using FLS from subjects without inflammatory arthritis (non-inflamed FLS) after activation with adiponectin and tumour necrosis factor (TNF) to mimic the early stage of RA [2].

Objectives

We aim to determine if the stimulation of non-inflamed FLS upregulates the expression of key-enzymes involved in glucose and glutamine metabolism and how the inhibition of those enzymes affects FLS activation.

Methods

FLS (passage 6-8) were isolated from synovial tissues of patients without inflammatory arthritis or osteoarthritis who underwent diagnostic arthroscopy due to a previous injury. FLS were cultured in DMEM medium (high glucose and GlutaMAX) containing 10% FBS and stimulated by known FLS-activators, i.e. TNF, interleukin 1 beta (IL-1 β), or adiponectin. For the inhibition experiments, cells were pre-treated with 25 mM 2-DG or 300 nM CB-839 for 4 hours before stimulation. Expressions of the enzymes were measured by western blot in whole-cell lysates and IL-6 was measured using ELISA in cell culture supernatants at 24 hours after stimulation. Cell proliferation was determined using MTT assay after 48 hours of stimulation.

Results

First, we compared the expression of hexokinase 2 (HK2), glutaminase C (GAC), and PFKFB3 in non-inflamed FLS before and after activation with adiponectin, TNF, and IL-1β. Expression of HK2 and GAC were upregulated in adiponectin- and TNF-activated FLS compared to unstimulated FLS. PFKFB3 was not affected by any of the stimuli. IL-1β did not affect the expression of the analysed enzymes (Figure 1A-C). As IL-1β did not affect the expression of metabolic enzymes, we continued stimulation only with adiponectin and TNF. TNF but not adiponectin significantly enhanced the proliferation of FLS without inhibition (Figure 1D). However, FLS proliferation was significantly reduced by pre-treatment with 2-DG, a glycolysis inhibitor, in unstimulated as well as TNF- and adiponectin-stimulated cells. CB-839, a glutaminase inhibitor, did not affect the proliferation of FLS (Figure 1D). Both TNF and adiponectin significantly upregulated the production of IL-6 in FLS. Pre-treatment with 2-DG significantly reduced the production of IL-6. CB-839 pre-treatment significantly reduced the production of IL-6 only in unstimulated FLS (Figure 1E).

Figure 1.

Metabolic alterations in non-inflamed FLS. Expression of hexokinase 2 (HK2; A), glutaminase C (GAC; B) and PFKFB3 (C) in non-inflamed FLS measured by western blot. Proliferation assay (MTT assay; D) and production of IL-6 (ELISA; E) was performed using cells treated with HK2 inhibitor 2-DG and glutaminase inhibitor CB-839. Statistical significance was determined as by one sample t test (A-C; n=7) or paired t test (D-E; n=4-6).

Conclusion

Our results show that the expression of key-enzymes regulating metabolic pathways can be enhanced by adiponectin and TNF in non-inflamed FLS. Moreover, we also show that inhibition of specific metabolic pathways can affect FLS activation differently depending on the cytokine stimulation. These results provide a deeper understanding of metabolic reprogramming in FLS in early RA.

References

[1]Bustamante, M.F., et al., Fibroblast-like synoviocyte metabolism in the pathogenesis of rheumatoid arthritis. Arthritis Res Ther, 2017. 19(1): p. 110.

[2]Zhang, Y., et al., Recombinant Adiponectin Induces the Production of Pro-Inflammatory Chemokines and Cytokines in Circulating Mononuclear Cells and Fibroblast-Like Synoviocytes From Non-Inflamed Subjects. Front Immunol, 2020. 11: p. 569883.

Disclosure of Interests

None declared.

Plasticity in structure and assembly of SARS-CoV-2 nucleocapsid protein

Worldwide SARS-CoV-2 sequencing efforts track emerging mutations in its spike protein, as well as characteristic mutations in other viral proteins. Besides their epidemiological importance, the observed SARS-CoV-2 sequences present an ensemble of viable protein variants, and thereby a source of information on viral protein structure and function. Charting the mutational landscape of the nucleocapsid (N) protein that facilitates viral assembly, we observe variability exceeding that of the spike protein, with more than 86% of residues that can be substituted, on average by three to four different amino acids. However, mutations exhibit an uneven distribution that tracks known structural features but also reveals highly protected stretches of unknown function. One of these conserved regions is in the central disordered linker proximal to the N-G215C mutation that has become dominant in the Delta variant, outcompeting G215 variants without further spike or N-protein substitutions. Structural models suggest that the G215C mutation stabilizes conserved transient helices in the disordered linker serving as protein-protein interaction interfaces. Comparing Delta variant N-protein to its ancestral version in biophysical experiments, we find a significantly more compact and less disordered structure. N-G215C exhibits substantially stronger self-association, shifting the unliganded protein from a dimeric to a tetrameric oligomeric state, which leads to enhanced coassembly with nucleic acids. This suggests that the sequence variability of N-protein is mirrored by high plasticity of N-protein biophysical properties, which we hypothesize can be exploited by SARS-CoV-2 to achieve greater efficiency of viral assembly, and thereby enhanced infectivity.