Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

COVID-19; Biosensor plasmónico; SerologíaCOVID-19; Biosensor plasmònic; SerologiaCOVID-19; Plasmonic biosensor; SerologySerological tests are essential for the control and management of COVID-19 pandemic (diagnostics and surveillance, and epidemiological and immunity studies). We introduce a direct serological biosensor assay employing proprietary technology based on plasmonics, which offers rapid (<15 min) identification and quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in clinical samples, without signal amplification. The portable plasmonic device employs a custom-designed multiantigen (RBD peptide and N protein) sensor biochip and reaches detection limits in the low ng mL–1 range employing polyclonal antibodies. It has also been implemented employing the WHO-approved anti-SARS-CoV-2 immunoglobulin standard. A clinical validation with COVID-19 positive and negative samples (n = 120) demonstrates its excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor as an accurate and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the disease management and for the evaluation of immunological status during vaccination or treatment.ICN2 and UVE acknowledge financial support from H2020 Research and Innovation Programme of the European Commission (H202-SC1-PHE-Coronavirus-2020, CONVAT Project, No. 101003544). The ICN2 is funded by the CERCA program/Generalitat de Catalunya and supported by the Severo Ochoa Centres of Excellence program funded by the Spanish Research Agency (AEI, grant no. SEV-2017-0706). ICN2 group is very grateful to EPI Industries (Barcelona, Spain) for its kind donation supporting our research in COVID-19. O.C.-L. acknowledges the economic support from the Spanish Ministry of Science and Innovation and the Spanish Research Agency and the European Social Fund (ESF) (ref. BES-2017-080527) linked to the TEC 2016-78515-R project Predict. A part of the work was supported by the European Virus Archive GLOBAL (EVA-GLOBAL) project that has received funding from the EU Horizon 2020 (grant agreement No. 871029). A.T. and L.F.-B. acknowledge financial support from GENCAT-DGRIS COVID. We are indebted to all the patients who accepted to participate contributing to science advancement. We are indebted to the HCB-IDIBAPS Biobank for the human samples and data procurement and to the Fundació Glòria Soler for its support to the COVIDBANK collection. We thank the IDIBAPS Biobank for its valuable contribution to sample processing and storage. The authors acknowledge the EU Horizon 2020 Program under grant agreement no. 644956 (RAIS project) for funding the Hospital Vall d’Hebron Biobank. The VHIR-HUVH is supported by Plan Nacional de I + D + i 2013-2016 and ISCIII-Ministerio de Ciencia e Innovación, and Spanish Network for Research in Infectious Diseases (REIPI RD16/0016/0003)─cofinanced by European Development Regional Fund “A way to achieve Europe,” Operative program Intelligent Growth 2014. Part of the samples and data from patients included in this study were provided by the Vall d’Hebron University Hospital Biobank (PT17/0015/0047), integrated in the Spanish National Biobanks Network, and they were processed following standard operating procedures with the appropriate approval of the Ethical and Scientific Committee. The authors kindly appreciate the generous donation of samples and clinical data of the donors of the Sepsis Bank of HUVH Biobank and COVID-19 patients attended at HUVH

Use of Biomarkers to Improve 28-Day Mortality Stratification in Patients with Sepsis and SOFA ≤ 6

Molecular diagnosis; Mortality; Sepsis biomarkersDiagnóstico molecular; Mortalidad; Biomarcadores de sepsisDiagnòstic molecular; Mortalitat; Biomarcadors de sèpsiaEarly diagnosis and appropriate treatments are crucial to reducing mortality risk in septic patients. Low SOFA scores and current biomarkers may not adequately discern patients that could develop severe organ dysfunction or have an elevated mortality risk. The aim of this prospective observational study was to evaluate the predictive value of the biomarkers mid-regional pro-adrenomedullin (MR-proADM), procalcitonin (PCT), C-reactive protein (CRP), and lactate for 28-day mortality in patients with sepsis, and patients with a SOFA score ≤6. 284 were included, with a 28-day all-cause mortality of 8.45% (n = 24). Non-survivors were older (p = 0.003), required mechanical ventilation (p = 0.04), were ventilated for longer (p = 0.02), and had higher APACHE II (p = 0.015) and SOFA (p = 0.027) scores. Lactate showed the highest predictive ability for all-cause 28-day mortality, with an area under the receiver-operating characteristic curve (AUROC) of 0.67 (0.55–0.79). The AUROC for all-cause 28-day mortality in patients with community-acquired infection was 0.69 (0.57–0.84) for SOFA and 0.70 (0.58–0.82) for MR-proADM. A 2.1 nmol/L cut-off point for this biomarker in this subgroup of patients discerned, with 100% sensibility, survivors from non-survivors at 28 days. In patients with community-acquired sepsis and initial SOFA score ≤ 6, MR-proADM could help identify patients at risk of 28-day mortality.This research was funded by a restricted grant from Thermo Fisher (Hennigsdorf, Germany), consisting of free-of-charge kits. However, the funding organization had no role in the collection, management, analysis, or interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication

Vitamin C deficiency in critically ill COVID-19 patients admitted to intensive care unit

COVID-19; SARS-CoV-2 pneumonia; Vitamin CCOVID-19; Neumonía por SARS-CoV-2; Vitamina CCOVID-19; Pneumònia per SARS-CoV-2; Vitamina CObjectives: To determine vitamin C plasma kinetics, through the measurement of vitamin C plasma concentrations, in critically ill Coronavirus infectious disease 2019 (COVID-19) patients, identifying eventually the onset of vitamin C deficiency. Design: Prospective, observational, single-center study. Setting: Intensive Care Unit (ICU), Vall d’Hebron University Hospital, Barcelona. Study period from November 12th, 2020, to February 24th, 2021. Patients: Patients who had a severe hypoxemic acute respiratory failure due to COVID-19 were included. Interventions: Plasma vitamin C concentrations were measured on days 1, 5, and 10 of ICU admission. There were no vitamin C enteral nor parenteral supplementation. The supportive treatment was performed following the standard of care or acute respiratory distress syndrome (ARDS) patients. Measurement: Plasma vitamin C concentrations were analyzed using an ultra-performance liquid chromatography (UPLC) system with a photodiode array detector (wavelength set to 245 nm). We categorized plasmatic levels of vitamin C as follows: undetectable: 5 mg/L). Main results: Forty-three patients were included (65% men; mean age 62 ± 10 years). The median Sequential Organ Failure Assessment (SOFA) score was 3 (1–4), and the Acute Physiology and Chronic Health disease Classification System (APACHE II) score was 13 (10–22). Five patients had shock. Bacterial coinfection was documented in 7 patients (16%). Initially all patients required high-flow oxygen therapy, and 23 (53%) further needed invasive mechanical ventilation during 21 (± 10) days. The worst PaO2/FIO2 registered was 93 (± 29). ICU and hospital survival were 77 and 74%, respectively. Low or undetectable levels remained constant throughout the study period in the vast majority of patients. Conclusion: This observational study showed vitamin C plasma levels were undetectable on ICU admission in 86% of patients with acute respiratory failure due to COVID-19 pneumonia requiring respiratory support. This finding remained consistent throughout the study period

Pulmonary Air Embolism in a Patient with COVID-19 with Extracorporeal Membrane Oxygenation Support

Embòlia aèria pulmonar; COVID-19Embolia aérea pulmonar; COVID-19Pulmonary air embolism; COVID-1

Case report: Cytokine hemoadsorption in a case of hemophagocytic lymphohistiocytosis secondary to extranodal NK/T-cell lymphoma

Cytokine hemoadsorption; Hemophagocytic lymphohistiocytosis; Multiorgan dysfunctionHemoadsorció de citocines; Limfohistiocitosi hemofagocítica; Disfunció multiorgànicaHemoadsorción de citoquinas; Linfohistiocitosis hemofagocítica; Disfunción multiorgánicaWe discuss a single case of Hemophagocytic lymphohistiocytosis (HLH) due to NK-type non-Hodgkin lymphoma and Epstein-Barr virus reactivation with multiorgan dysfunction and distributive shock in which we performed cytokine hemoadsorption with Cytosorb ®. A full microbiological panel was carried out, including screening for imported disease, standard serologies and cultures for bacterial and fungal infection. A liver biopsy and bone marrow aspirate were performed, confirming the diagnosis. The patients fulfilled the HLH-2004 diagnostic criteria, and according to the 2018 Consensus Statements by the HLH Steering Committee of the Histiocyte Society, dexamethasone and etoposide were started. There was an associated hypercytokinemia and, due to refractory distributive shock, rescue therapy with cytokine hemoadsorption was performed during 24 h (within day 2 and 3 from ICU admission). After starting this procedure, rapid hemodynamic control was achieved with a significant reduction in vasopressor support requirements. This case report highlights that cytokine hemoadsorption can be an effective since rapid decrease in IL-10 levels and a significant hemodynamic improvement was achieved

Label-Free Plasmonic Biosensor for Rapid, Quantitative, and Highly Sensitive COVID-19 Serology: Implementation and Clinical Validation

Serological tests are essential for the control and management of COVID-19 pandemic, not only for current and historical diagnostics but especially for surveillance, epidemiological, and acquired immunity studies. Clinical COVID-19 serology is routinely performed by enzymatic or chemiluminescence immunoassays (i.e., ELISA or CLIA), which provide good sensitivities at the expense of relatively long turnaround times and specialized laboratory settings. Rapid serological tests, based on lateral flow assays, have also been developed and widely commercialized, but they suffer from limited reliability due to relatively low sensitivity and specificity. We have developed and validated a direct serological biosensor assay employing proprietary technology based on Surface Plasmon Resonance (SPR). The biosensor offers a rapid -less than 15 min- identification and quantification of SARS-CoV-2 antibodies directly in clinical samples, without the need of any signal amplification. The portable plasmonic biosensor device employs a custom-designed multi-antigen sensor biochip, combining the two main viral antigens (RBD peptide and N protein), for simultaneous detection of human antibodies targeting both antigens. The SPR serology assay reaches detection limits in the low ng mL-1 range employing polyclonal antibodies as standard, which are well below the commonly detected antibody levels in COVID-19 patients. The assay has also been implemented employing the first WHO approved anti-SARS-CoV-2 immunoglobulin standard. We have carried out a clinical validation with COVID-19 positive and negative samples (n=120) that demonstrates the excellent diagnostic sensitivity (99%) and specificity (100%). This positions our biosensor device as an accurate, robust, and easy-to-use diagnostics tool for rapid and reliable COVID-19 serology to be employed both at laboratory and decentralized settings for the management of COVID-19 patients and for the evaluation of immunological status during vaccination, treatment or in front of emerging variants.<br /

Comparative outcomes of extracorporeal membrane oxygenation for COVID-19 delivered in experienced European centres during successive SARS-CoV-2 variant outbreaksan international multicentre retrospective cohort study

International audienc

Comparative outcomes of extracorporeal membrane oxygenation for COVID-19 delivered in experienced European centres during successive SARS-CoV-2 variant outbreaksan international multicentre retrospective cohort study

International audienc