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INTRODUCTION: This study aimed to determine whether the introduction of anti-SARS-CoV-2 vaccines and the dominance of the omicron variant had a significant impact on the outcome of COVID-19 in patients with systemic autoimmune rheumatic diseases (SAIRDs). METHODS: Using data entered to the Greek Rheumatology Society COVID-19 registry, we investigated the incidence of hospitalization and death due to COVID-19, during the successive periods of the pandemic according to the prevalent strain (wild-type, Alpha, Delta, Omicron) in vaccinated and unvaccinated patients. Variables independently associated with hospitalization and death were explored using multivariate regression analyses, while Kaplan-Meier curves were used to depict survival data. RESULTS: From August 2020 until June 30, 2022, 456 cases (70.2% females) of COVID-19 with a mean age (± SD) of 51.4 ± 14.0 years were reported. In unvaccinated patients, the proportions of hospitalization and death were 24.5% and 4%, compared to 12.5% and 0.8% in the vaccinated group (p < 0.001 for both comparisons). The rates of hospitalization for the wild-type, Alpha, Delta, and Omicron periods were 24.7%, 31.3%, 25.9%, and 8.1% respectively (p < 0.0001), while the case fatality rates were 2.7%, 4%, 7%, and 0%, respectively (p = 0.001). Using multivariable regression analysis, factors independently associated with hospitalization were infection by a non-Omicron variant, being non-vaccinated, exposure to rituximab, older age, and respiratory and cardiovascular disease. Independent predictors for death were contracting COVID-19 during the Alpha or Delta period, pulmonary disease, and older age, while being vaccinated was protective. CONCLUSIONS: In this 2-year analysis, the rates of hospitalization and death among patients with SAIRDs have declined significantly. Vaccination and the dominance of the Omicron variant appear to be the major determinants for this shift. Key points ⢠During the late phase of the pandemic, the proportion of severe COVID-19 cases, defined as requiring hospitalization or resulting in death, in patients with systemic autoimmune rheumatic diseases has declined. ⢠Anti-SARS-CoV-2 vaccination and the dominance of the Omicron strain are the key factors that have independently contributed to this shift.
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COVID-19 , Enfermedades Reumáticas , Femenino , Humanos , Adulto , Persona de Mediana Edad , Anciano , Masculino , COVID-19/epidemiología , COVID-19/prevención & control , SARS-CoV-2 , Vacunación , Enfermedades Reumáticas/epidemiologíaRESUMEN
Ice-binding proteins (IBPs) from extremophile organisms can modulate ice formation and growth. There are many (bio)technological applications of IBPs, from cryopreservation to mitigating freeze-thaw damage in concrete to frozen food texture modifiers. Extraction or expression of IBPs can be challenging to scale up, and hence polymeric biomimetics have emerged. It is, however, desirable to use biosourced monomers and heteroatom-containing backbones in polymers for in vivo or environmental applications to allow degradation. Here we investigate high molecular weight polyproline as an ice recrystallization inhibitor (IRI). Low molecular weight polyproline is known to be a weak IRI. Its activity is hypothesized to be due to the unique PPI helix it adopts, but it has not been thoroughly investigated. Here an open-to-air aqueous N-carboxyanhydride polymerization is employed to obtain polyproline with molecular weights of up to 50000 g mol-1. These polymers were found to have IRI activity down to 5 mg mL-1, unlike a control peptide of polysarcosine, which did not inhibit all ice growth at up to 40 mg mL-1. The polyprolines exhibited lower critical solution temperature behavior and assembly/aggregation observed at room temperature, which may contribute to its activity. Single ice crystal assays with polyproline led to faceting, consistent with specific ice-face binding. This work shows that non-vinyl-based polymers can be designed to inhibit ice recrystallization and may offer a more sustainable or environmentally acceptable, while synthetically scalable, route to large-scale applications.
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Hielo , Péptidos , Peso Molecular , Inhibidores de CrecimientoRESUMEN
To evaluate the effect of the phosphodiesterase 4 inhibitor apremilast in biologic-naïve patients with early peripheral PsA in terms of disease activity, clinical manifestations, patient-perceived outcomes, as well as apremilast's safety profile in routine care settings of Greece. Non-interventional, multicenter, 52-week prospective cohort study, enrolling biologic-naïve patients with early active peripheral PsA who started apremilast after intolerance or inadequate response (within the first 12 months of treatment) to an initial conventional synthetic (cs)DMARD treatment. Non-responder imputation was applied for missing data.In total, 167 consecutive patients (mean age: 52.5 years; median PsA duration: 0.9 years) were analyzed. At baseline, the median (interquartile range) clinical Disease Activity in Psoriatic Arthritis (cDAPSA) score was 22.0 (16.0-29.0), with 86.8% of patients having at least moderate (29.3% high) disease activity; 87.4% had skin psoriasis, 37.7% nail psoriasis, 30.7% enthesitis, and 12.4% dactylitis. At 16, 24, and 52 weeks, 28.7, 42.5, and 48.5% of patients, achieved ≥ 50% improvement in their baseline cDAPSA score, respectively. At week 52, 55.6, 50, and 26.8% of evaluable patients achieved complete resolution of enthesitis, dactylitis and nail psoriasis, respectively. Improvements were also observed in patient's health state assessed by the Psoriatic Arthritis Impact of Disease 12-item questionnaire, and health-related quality of life. The 52-week drug survival rate was 75%, while 13.8% of patients experienced at least one adverse drug reaction.Biologic-naïve patients with early PsA, treated with apremilast experienced significant improvements in disease activity, extra-articular manifestations and patient-centered outcomes, accompanied by a favorable tolerability profile.
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Antiinflamatorios no Esteroideos , Artritis Psoriásica , Productos Biológicos , Psoriasis , Humanos , Persona de Mediana Edad , Artritis Psoriásica/tratamiento farmacológico , Productos Biológicos/uso terapéutico , Entesopatía , Estudios Prospectivos , Psoriasis/tratamiento farmacológico , Calidad de VidaRESUMEN
Glycoforms (and other post-translational modifications) of otherwise identical proteins can indicate pathogenesis/disease state and hence new tools to detect and sense a protein's glycosylation status are essential. Antibody-based assays against specific protein sequences do not typically discriminate between glycoforms. Here we demonstrate a 'sandwich' bio-assay approach, whereby antibodies immobilised onto biolayer interferometry sensors first select proteins, and then the specific glycoform is identified using gold nanoparticles functionalised with lectins which provide signal enhancement. The nanoparticles significantly enhance the signal relative to lectins alone, allowing glycoform specific detection as low as 0.04 µg mL-1 (1.4 nM) in buffer, and crucially there is no need for an enrichment step and all steps can be automated. Proof of concept is demonstrated using prostate specific antigen: a biomarker for prostate cancer, where glycoform analysis could distinguish between cancerous and non-cancerous status, rather than only detecting overall protein concentration.
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Lectinas , Nanopartículas del Metal , Humanos , Masculino , Anticuerpos , Glicosilación , Oro , Lectinas/metabolismo , Neoplasias de la Próstata/diagnóstico , Antígeno Prostático Específico/análisisRESUMEN
Conventional cryopreservation solutions rely on the addition of organic solvents such as DMSO or glycerol, but these do not give full recovery for all cell types, and innovative cryoprotectants may address damage pathways which these solvents do not protect against. Macromolecular cryoprotectants are emerging, but there is a need to understand their structure-property relationships and mechanisms of action. Here we synthesized and investigated the cryoprotective behavior of sulfoxide (i.e., "DMSO-like") side-chain polymers, which have been reported to be cryoprotective using poly(ethylene glycol)-based polymers. We also wanted to determine if the polarized sulfoxide bond (S+O- character) introduces cryoprotective effects, as this has been seen for mixed-charge cryoprotective polyampholytes, whose mechanism of action is not yet understood. Poly(2-(methylsulfinyl)ethyl methacrylate) was synthesized by RAFT polymerization of 2-(methylthio)ethyl methacrylate and subsequent oxidation to sulfoxide. A corresponding N-oxide polymer was also prepared and characterized: (poly(2-(dimethylamineoxide)ethyl methacrylate). Ice recrystallization inhibition assays and differential scanning calorimetry analysis show that the sulfoxide side chains do not modulate the frozen components during cryopreservation. In cytotoxicity assays, it was found that long-term (24 h) exposure of the polymers was not tolerated by cells, but shorter (30 min) incubation times, which are relevant for cryopreservation, were tolerated. It was also observed that overoxidation to the sulfone significantly increased the cytotoxicity, and hence, these materials require a precision oxidation step to be deployed. In suspension cell cryopreservation investigations, the polysulfoxides did not increase cell recovery 24 h post-thaw. These results show that unlike hydrophilic backboned polysulfides, which can aid cryopreservation, the installation of the sulfoxide group onto a polymer does not necessarily bring cryoprotective properties, highlighting the challenges of developing and discovering macromolecular cryoprotectants.
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Ice binding proteins (IBP) have evolved to limit the growth of ice but also to promote ice formation by ice-nucleating proteins (INPs). IBPs, which modulate these seemingly distinct processes, often have high sequence similarities, and molecular size/assembly is hypothesized to be a crucial determinant. There are only a few synthetic materials that reproduce INP function, and rational design of ice nucleators has not been achieved due to outstanding questions about the mechanisms of ice binding. Poly(vinyl alcohol) (PVA) is a water-soluble synthetic polymer well known to effectively block ice recrystallization, by binding to ice. Here, we report the synthesis of a polymeric ice nucleator, which mimics the dense assembly of IBPs, using confined ice-binding polymers in a high-molar-mass molecular bottlebrush. Poly(vinyl alcohol)-based molecular bottlebrushes with different side-chain densities were synthesized via a combination of ring-opening metathesis polymerization (ROMP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization, using "grafting-to" and "grafting-through" approaches. The facile preparation of the PVA bottlebrushes was performed via selective hydrolysis of the acetate of the poly(vinyl acetate) (PVAc) side chains of the PVAc bottlebrush precursors. Ice-binding polymer side-chain density was shown to be crucial for nucleation activity, with less dense brushes resulting in colder nucleation than denser brushes. This bio-inspired approach provides a synthetic framework for probing heterogeneous ice nucleation and a route toward defined synthetic nucleators for biotechnological applications.
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Hielo , Alcohol Polivinílico , Alcohol Polivinílico/química , Polimerizacion , Polímeros/química , Peso MolecularRESUMEN
Glycan-lectin interactions play essential roles in biology; as the site of attachment for pathogens, cell-cell communication, and as crucial players in the immune system. Identifying if a new glycan (natural or unnatural) binds a protein partner, or if a new protein (or mutant) binds a glycan remains a non-trivial problem, with few accessible or low-cost tools available. Micro-arrays allow for the interrogation of 100's of glycans but are not widely available in individual laboratories. Biophysical techniques such as isothermal titration calorimetry, surface plasmon resonance spectrometry, biolayer interferometry and nuclear magnetic resonance spectroscopy all provide detailed understanding of glycan binding but are relatively expensive. Glycosylated plasmonic nanoparticles based on gold cores with polymeric tethers have emerged as biosensors to detect glycan-protein binding, based on colourimetric (red to blue) outputs which can be easily interpreted by a simple UV-visible spectrometer or by eye. Despite the large number of reports there are no standard protocols for each system or recommended start points, to allow a new user to deploy this technology. Here we explore the key parameters of nanoparticle size, polymeric tether length and gold concentration to provide some guidelines for how polymer-tethered glycosylated gold nanoparticles can be used to probe a new glycan/protein interactions, with minimal optimisation barriers. This work aimed to remove the need to explore chemical and nanoparticle space and hence remove a barrier for other users when deploying this system. We show that the concentration of the gold core is crucial to balance strong responses versus false positives and recommend a gold core size and polymer tether length which balances sufficient colloidal stability and output. Whilst subtle differences between glycans/lectins will impact the outcomes, these parameters should enable a lab user to quickly evaluate binding using minimal quantities of the glycan and lectin, to select candidates for further study.
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Upon exposure to biological fluids, the fouling of nanomaterial surfaces results in non-specific capture of proteins, which is particularly important when in contact with blood for in vivo and ex vivo applications. It is crucial to evaluate not just the protein components but also the glycans attached to those proteins. Polymer-tethered glycosylated gold nanoparticles have shown promise for use in biosensing/diagnostics, but the impact of the glycoprotein corona has not been established. Here we investigate how polymer-tethered glycosylated gold nanoparticles interact with serum proteins and demonstrate that the protein corona introduces new glycans and hence off-specific targeting capability. Using a panel of RAFT-derived polymers grafted to the gold surface, we show that the extent of corona formation is not dependent on the type of polymer. In lectin-binding assays, a glycan (galactose) installed on the chain-end of the polymer was available for binding even after protein corona formation. However, using sialic-acid binding lectins, it was found that there was significant off-target binding due to the large density of sialic acids introduced in the corona, confirmed by western blotting. To demonstrate the importance, we show that the nanoparticles can bind Siglec-2, an immune-relevant lectin post-corona formation. Pre-coating with (non-glycosylated) bovine serum albumin led to a significant reduction in the total glycoprotein corona. However, sufficient sialic acids were still present in the residual corona to lead to off-target binding. These results demonstrate the importance of the glycans when considering the protein corona and how 'retention of the desired function' does not rule out 'installation of undesired function' when considering the performance of glyco-nanomaterials.
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Nanopartículas del Metal , Nanopartículas , Corona de Proteínas , Galactosa , Glicoproteínas , Oro , Lectinas , Nanopartículas/metabolismo , Polímeros/metabolismo , Polisacáridos , Unión Proteica , Corona de Proteínas/metabolismo , Albúmina Sérica Bovina/metabolismo , Lectina 2 Similar a Ig de Unión al Ácido Siálico/metabolismo , Ácidos Siálicos/metabolismoRESUMEN
Objectives: We report the effectiveness and safety of certolizumab pegol (CZP) treatment in a real-world Greek axial spondyloarthritis (axSpA) population, including patients with radiographic (r-axSpA) and non-radiographic (nr-axSpA) disease. Methods: We performed a sub-analysis of the Greek cohort from CIMAX (NCT02354105), a multicentre, non-interventional cohort study that prospectively investigated CZP treatment in patients with axSpA. The primary outcome was change from baseline (CfB) in Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) to Week 52. Results: Across 12 sites in Greece, 126 patients (r-axSpA: 91; nr-axSpA: 35) received ≥1 dose of CZP and were included in the Safety Set (SS), with 120 patients (r-axSpA: 86; nr-axSpA: 34) included in the Full Analysis Set (FAS). The mean (standard deviation [SD]) CfB in BASDAI at Week 52 was -3.8 (2.0) in the overall axSpA population, with numerically greater improvements observed for nr-axSpA patients compared with r-axSpA (nr-axSpA: -4.2 [2.1]; r-axSpA: -3.7 [2.0]). Improvements in the axSpA population, including r-axSpA and nr-axSpA subpopulations, were observed in key secondary and additional outcomes at Week 52. Overall, 14.3% (18/126) of patients in the axSpA population experienced ≥1 adverse event (AE). There were no serious AEs or deaths reported during the study. Conclusions: Patients with r-axSpA and nr-axSpA treated with CZP in clinical practice in Greece showed improvements in disease activity and key symptoms. CZP treatment may therefore help address the substantial health burden associated with axSpA in Greece.
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Current point-of-care lateral flow immunoassays, such as the home pregnancy test, rely on proteins as detection units (e.g. antibodies) to sense for analytes. Glycans play a fundamental role in biological signalling and recognition events such as pathogen adhesion and hence they are promising future alternatives to antibody-based biosensing and diagnostics. Here we introduce the potential of glycans coupled to gold nanoparticles as recognition agents for lateral flow diagnostics. We first introduce the concept of lateral flow, including a case study of lateral flow use in the field compared to other diagnostic tools. We then introduce glycosylated materials, the affinity gains achieved by the cluster glycoside effect and the current use of these in aggregation based assays. Finally, the potential role of glycans in lateral flow are explained, and examples of their successful use given.
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Técnicas Biosensibles , Nanopartículas del Metal , Anticuerpos , Oro , Inmunoensayo , Sistemas de Atención de PuntoRESUMEN
The COVID-19 pandemic has highlighted the need for innovative biosensing, diagnostic, and surveillance platforms. Here we report that glycosylated, polymer-stabilized, gold nanorods can bind the SARS-CoV-2 spike protein and show correlation to the presence of SARS-CoV-2 in primary COVID-19 clinical samples. Telechelic polymers were prepared by reversible addition-fragmentation chain-transfer polymerization, enabling the capture of 2,3-sialyllactose and immobilization onto gold nanorods. Control experiments with a panel of lectins and a galactosamine-terminated polymer confirmed the selective binding. The glycosylated rods were shown to give dose-dependent responses against recombinant truncated SARS-CoV-2 spike protein, and the responses were further correlated using primary patient swab samples. The essentiality of the anisotropic particles for reducing the background interference is demonstrated. This highlights the utility of polymer tethering of glycans for plasmonic biosensors of infection.
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COVID-19 , Nanotubos , COVID-19/diagnóstico , Oro , Humanos , Pandemias , Polímeros , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/metabolismoRESUMEN
Objectives: SENSE was an international, non-interventional cross-sectional study that assessed treatment satisfaction in patients with suboptimally controlled active rheumatoid arthritis (RA) who were under treatment with any approved agent exposed to ≤ 2 biological disease-modifying anti-rheumatic drugs (DMARDs) at the time of enrolment. The current publication concerns the subanalysis of the results from the Greek cohort. Methods: Treatment satisfaction was assessed with Treatment Satisfaction Questionnaire for Medication (TSQM), with good treatment satisfaction defined as TSQM global ≥80. Adherence to therapy was recorded on a visual analogue scale (VAS) and treatment expectations were assessed on a 7-point numerical rating scale. Results: Of 121 patients, 82.6% were women, of mean age 64.8 years and mean time from diagnosis 8.4 years. Patients had active disease (mean DAS28-ESR 4.5) and compromised functional status (mean [SD] HAQ-DI 1.1 [0.7]) while on treatment (43.8% on biologics and 5% on steroids). The mean TSQM global was 66.9. Treatment expectations were "general improvement of arthritis" and "less joint pain" (mean score [SD], 4.9 [1.8] each), "more joint flexibility" (4.8 [1.9]), and "lasting relief of RA symptoms" (4.8 [2.1]). Oral administration was preferred by 65.3% of patients. Good self-reported adherence (≥80%) was recorded in 93.4% of the patients. Treatment switch to another DMARD was planned by treating rheumatologist for only 49.6% of the participants, despite suboptimal RA control. Conclusion: Patients with suboptimally controlled RA in Greece have low treatment satisfaction and poor self-reported outcomes, albeit high self-reported treatment adherence. Similarly to the global SENSE study results, the need for patient-centric treatment approaches in order to improve disease outcomes is emphasised.
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Lateral flow devices are rapid (and often low cost) point-of-care diagnostics-the classic example being the home pregnancy test. A test line (the stationary phase) is typically prepared by the physisorption of an antibody, which binds to analytes/antigens such as viruses, toxins, or hormones. However, there is no intrinsic requirement for the detection unit to be an antibody, and incorporating other ligand classes may bring new functionalities or detection capabilities. To enable other (nonprotein) ligands to be deployed in lateral flow devices, they must be physiosorbed to the stationary phase as a conjugate, which currently would be a high-molecular-weight carrier protein, which requires (challenging) chemoselective modifications and purification. Here, we demonstrate that poly(vinylpyrrolidone), PVP, is a candidate for a polymeric, protein-free test line, owing to its unique balance of water solubility (for printing) and adhesion to the nitrocellulose stationary phase. End-functionalized PVPs were prepared by RAFT polymerization, and the model capture ligands of biotin and galactosamine were installed on PVP and subsequently immobilized on nitrocellulose. This polymeric test line was validated in both flow-through and full lateral flow formats using streptavidin and soybean agglutinin and is the first demonstration of an "all-polymer" approach for installation of capture units. This work illustrates the potential of polymeric scaffolds as anchoring agents for small-molecule capture agents in the next generation of robust and modular lateral flow devices and that macromolecular engineering may provide real benefit.
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The management of acute gout in the hospital setting may be challenging since most patients are elderly with multiple unstable comorbidities. However, there are no prospective clinical trials for hospitalized patients with gout to guide optimal management. Evidence indicates that steroids or adrenocorticotropic hormone (ACTH) may be effective and safe therapeutic options for these patients. This study aimed at directly comparing the efficacy and safety of ACTH vs betamethasone for the treatment of gout in hospitalized patients. This is the first prospective clinical trial for hospitalized patients with gout. We designed a randomized, open label study to assess the efficacy and safety of a single intramuscular injection of either ACTH or betamethasone in hospitalized patients with acute gout. Primary efficacy endpoints were the change in intensity of pain as recorded using a Visual Analogue Scale (VAS) at baseline compared to 24 h (ΔVAS24h), and 48 h. Moreover, we assessed safety and effects on the hypothalamic-pituitary-adrenal (HPA) axis, glucose and lipid homeostasis, bone metabolism, electrolytes and renal function. 38 patients were recruited. Both treatments were highly effective. The mean ± SE ΔVAS24h and ΔVAS48h for ACTH was 4.48 ± 0.29 and 5.58 ± 0.26, respectively. The mean ± SE ΔVAS24h and ΔVAS48h for betamethasone was 4.67 ± 0.32 and 5.67 ± 0.28, respectively. Direct comparison between the two groups at 24 h and 48 h did not show statistically significant differences. Both treatments were well tolerated and safe. The effects on all metabolic parameters were mostly minimal and transient for both treatments. However, ACTH may affect less the HPA axis and bone metabolism compared to betamethasone, thus leading to the conclusion that. ACTH and betamethasone are effective and safe for the management of acute gout in hospitalized patients but that ACTH may associate with less disturbance of the HPA axis and bone metabolism. Our data support the use of both drugs as first line treatments for hospitalized patients with gout.Clinical trial registration: ClinicalTrials.gov NCT04306653.
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Artritis Gotosa , Gota , Hormona Adrenocorticotrópica/efectos adversos , Anciano , Artritis Gotosa/tratamiento farmacológico , Betametasona , Gota/tratamiento farmacológico , Humanos , Sistema Hipotálamo-Hipofisario , Sistema Hipófiso-Suprarrenal , Estudios Prospectivos , Esteroides/uso terapéuticoRESUMEN
Introduction: Patients with rheumatoid arthritis (RA) are at increased risk for serious infections. Pneumococcal vaccination is among the most important preventive measures, however, vaccine uptake is suboptimal. We explored the rate and factors associated with pneumococcal vaccination in a contemporary RA cohort. Materials and methods: Multi-center, prospective, RA cohort study in Greece. Patient and disease characteristics and influenza and pneumococcal vaccinations were documented at baseline and 3 years later. Results: One thousand six hundred and ninety-seven patients were included and 34.5% had already received at least one pneumococcal vaccine at baseline. Among 1,111 non-vaccinated patients, 40.1% received pneumococcal vaccination during follow-up, increasing the vaccine coverage to 60.8%. By multivariate analysis, positive predictors for pneumococcal vaccination included prescription of influenza vaccine (OR = 33.35, 95% CI: 18.58-59.85), history of cancer (OR = 2.35, 95% CI: 1.09-5.06), bDMARD use (OR = 1.85, 95% CI: 1.29-2.65), seropositivity (OR = 1.47, 95% CI: 1.05-2.05), and high disease activity (DAS28-ESR, OR = 1.33, 95% CI: 1.17-1.51). Male sex (OR = 0.65, 95% CI: 0.43-0.99) was a negative predictor for pneumococcal vaccination during follow-up. Discussion: Despite increasing rates of pneumococcal vaccine coverage, 40% of RA patients remain unvaccinated. Severe disease, bDMARD use, comorbidities, and more importantly flu vaccination were the most significant factors associated with pneumococcal vaccination, emphasizing the currently unmet need for cultivating a "vaccination culture" in RA patients.
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Lateral flow immuno-assays, such as the home pregnancy test, are rapid point-of-care diagnostics that use antibody-coated nanoparticles to bind antigens/analytes (e.g., viruses, toxins or hormones). Ease of use, no need for centralized infrastructure and low-cost, makes these devices appealing for rapid disease identification, especially in low-resource environments. Here glycosylated polymer-coated nanoparticles are demonstrated for the sensitive, label-free detection of lectins in lateral flow and flow-through. The systems introduced here use glycans, not antibodies, to provide recognition: a "lateral flow glyco-assay," providing unique biosensing opportunities. Glycans are installed onto polymer termini and immobilized onto gold nanoparticles, providing colloidal stability but crucially also introducing assay tunability and selectivity. Using soybean agglutinin and Ricinus communis agglutinin I (RCA120 ) as model analytes, the impact of polymer chain length and nanoparticle core size are evaluated, with chain length found to have a significant effect on signal generation-highlighting the need to control the macromolecular architecture to tune response. With optimized systems, lectins are detectable at subnanomolar concentrations, comparable to antibody-based systems. Complete lateral flow devices are also assembled to show how these devices can be deployed in the "real world." This work shows that glycan-binding can be a valuable tool in rapid diagnostics.
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Oro , Nanopartículas del Metal , Bioensayo , Oro/química , Lectinas/metabolismo , PolímerosRESUMEN
OBJECTIVE: Τo report outcomes of breakthrough COVID-19 in comparison with COVID-19 in unvaccinated patients with systemic rheumatic diseases (SRDs). METHODS: Patients with SRD with COVID-19 (vaccinated and unvaccinated) were included by their rheumatologists in a registry operated by the Greek Rheumatology Society in a voluntarily basis. Type, date and doses of SARS-CoV-2 vaccines were recorded, and demographics, type of SRD, concurrent treatment, comorbidities and COVID-19 outcomes (hospitalisation, need for oxygen supplementation and death) were compared between vaccinated and unvaccinated patients. RESULTS: Between 1 March 2020 and 31 August 2021, 195 patients with SRD with COVID-19 were included; 147 unvaccinated and 48 vaccinated with at least one dose of a SARS-CoV-2 vaccine (Pfizer n=38 or AstraZeneca n=10). Among vaccinated patients, 29 developed breakthrough COVID-19 >14 days after the second vaccine dose (fully vaccinated), while 19 between the first and <14 days after the second vaccine dose (partially vaccinated). Despite no differences in demographics, SRD type, treatment or comorbidities between unvaccinated and vaccinated patients, hospitalisation and mortality rates were higher in unvaccinated (29.3% and 4.1%, respectively) compared with partially vaccinated (21% and 0%) or fully vaccinated (10.3% and 0%) patients. CONCLUSIONS: Vaccinated patients with SRD with breakthrough COVID-19 have better outcomes compared with unvaccinated counterparts with similar disease/treatment characteristics.
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COVID-19 , Enfermedades Reumáticas , COVID-19/prevención & control , Vacunas contra la COVID-19 , Hospitalización , Humanos , Enfermedades Reumáticas/tratamiento farmacológico , SARS-CoV-2RESUMEN
The COVID-19 pandemic, and future pandemics, require diagnostic tools to track disease spread and guide the isolation of (a)symptomatic individuals. Lateral-flow diagnostics (LFDs) are rapid and of lower cost than molecular (genetic) tests, with current LFDs using antibodies as their recognition units. Herein, we develop a prototype flow-through device (related, but distinct to LFDs), utilizing N-acetyl neuraminic acid-functionalized, polymer-coated, gold nanoparticles as the detection/capture unit for SARS-COV-2, by targeting the sialic acid-binding site of the spike protein. The prototype device can give rapid results, with higher viral loads being faster than lower viral loads. The prototype's effectiveness is demonstrated using spike protein, lentiviral models, and a panel of heat-inactivated primary patient nasal swabs. The device was also shown to retain detection capability toward recombinant spike proteins from several variants (mutants) of concern. This study provides the proof of principle that glyco-lateral-flow devices could be developed to be used in the tracking monitoring of infectious agents, to complement, or as alternatives to antibody-based systems.
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COVID-19 , Nanopartículas del Metal , Oro , Humanos , Pandemias , Polisacáridos , SARS-CoV-2RESUMEN
A new comprehensive analytical approach based on single-particle inductively coupled plasma-sector field mass spectrometry (spICP-SFMS) and electrical asymmetric-flow field-flow-fractionation combined with multi-angle light scattering detection (EAF4-MALS) has been examined for the characterization of galactosamine-terminated poly(N-hydroxyethyl acrylamide)-coated gold nanorods (GNRs) in two different degrees of polymerization (DP) by tuning the feed ratio (short: DP 35; long: DP 60). spICP-SFMS provided information on the particle number concentration, size and size distribution of the GNRs, and was found to be useful as an orthogonal method for fast characterization of GNRs. Glycoconjugated GNRs were separated and characterized via EAF4-MALS in terms of their size and charge and compared to the bare GNRs. In contrast to spICP-SFMS, EAF4-MALS was also able of providing an estimate of the thickness of the glycopolymer coating on the GNRs surface.
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Gold nanorods (GNRs) are a promising platform for nanoplasmonic biosensing. The localised surface plasmon resonance (LSPR) peak of GNRs is located in the near-infrared optical window and is sensitive to local binding events, enabling label-free detection of biomarkers in complex biological fluids. A key challenge in the development of such sensors is achieving target affinity and selectivity, while both minimizing non-specific binding and maintaining colloidal stability. Herein, we reveal how GNRs decorated with galactosamine-terminated polymer ligands display significantly different binding responses in buffer compared to serum, due to biocorona formation, and how biocorona displacement due to lectin binding plays a key role in their optical responses. GNRs were coated with either poly(N-(2-hydroxypropyl)methacrylamide) (PHPMA) or poly(N-hydroxyethyl acrylamide) (PHEA) prepared via reversible addition-fragmentation chain-transfer (RAFT) polymerisation and end-functionalised with galactosamine (Gal) as the lectin-targeting unit. In buffer Gal-PHEA-coated GNRs aggregated upon soybean agglutinin (SBA) addition, whereas Gal-PHPMA-coated GNRs exhibited a red-shift of the LSPR spectrum without aggregation. In contrast, when incubated in serum Gal-PHPMA-coated nanorods showed no binding response, while Gal-PHEA GNRs exhibited a dose-dependent blue-shift of the LSPR peak, which is the opposite direction (red-shift) to what was observed in buffer. This differential behaviour was attributed to biocorona formation onto both polymer-coated GNRs, shown by differential centrifugal sedimentation and nanoparticle tracking analysis. Upon addition of SBA to the Gal-PHEA coated nanorods, signal was generated due to displacement of weakly-bound biocorona components by lectin binding. However, in the case of Gal-PHPMA which had a thicker corona, attributed to lower polymer grafting densities, addition of SBA did not lead to biocorona displacement and there was no signal output. These results show that plasmonic optical responses in complex biological media can be significantly affected by biocorona formation, and that biocorona formation itself does not prevent sensing so long as its exact nature (e.g. 'hard versus soft') is tuned.