Vaccine breakthrough hypoxemic COVID-19 pneumonia in patients with auto-Abs neutralizing type I IFNs

Life-threatening `breakthrough' cases of critical COVID-19 are attributed to poor or waning antibody response to the SARS- CoV-2 vaccine in individuals already at risk. Pre-existing autoantibodies (auto-Abs) neutralizing type I IFNs underlie at least 15% of critical COVID-19 pneumonia cases in unvaccinated individuals; however, their contribution to hypoxemic breakthrough cases in vaccinated people remains unknown. Here, we studied a cohort of 48 individuals ( age 20-86 years) who received 2 doses of an mRNA vaccine and developed a breakthrough infection with hypoxemic COVID-19 pneumonia 2 weeks to 4 months later. Antibody levels to the vaccine, neutralization of the virus, and auto- Abs to type I IFNs were measured in the plasma. Forty-two individuals had no known deficiency of B cell immunity and a normal antibody response to the vaccine. Among them, ten (24%) had auto-Abs neutralizing type I IFNs (aged 43-86 years). Eight of these ten patients had auto-Abs neutralizing both IFN-a2 and IFN-., while two neutralized IFN-omega only. No patient neutralized IFN-ss. Seven neutralized 10 ng/mL of type I IFNs, and three 100 pg/mL only. Seven patients neutralized SARS-CoV-2 D614G and the Delta variant (B.1.617.2) efficiently, while one patient neutralized Delta slightly less efficiently. Two of the three patients neutralizing only 100 pg/mL of type I IFNs neutralized both D61G and Delta less efficiently. Despite two mRNA vaccine inoculations and the presence of circulating antibodies capable of neutralizing SARS-CoV-2, auto-Abs neutralizing type I IFNs may underlie a significant proportion of hypoxemic COVID-19 pneumonia cases, highlighting the importance of this particularly vulnerable population

NMR structural investigations and conformational analysis of condensed tannins. A continuing challenge due to the restricted rotation about the interflavanoid linkage

International audienc

Influence of stainless steel surface treatment on the oxygen reduction reaction in seawater

cited By 105International audienceThe oxygen reduction reaction on stainless steels (SSs) was studied in natural seawater with a rotating disk electrode and a rotating ring-disk electrode. Different surface treatments have been performed: prereduction, polishing, passivation and chemical treatment. X-ray photoelectron spectroscopy has been used to characterize the oxide films. The processes of O2 reduction are markedly influenced by the surface oxides and the reduction rate increases in the following order: chemically treated surface<passivated surface<mechanically polished surface<prereduced surface. An effect of the content of iron (FeII) in the oxide films and of Ni are suggested. On prereduced surfaces, O2 is reduced mainly through the four electron pathway, whereas the 2e- and 4e- occur on polished SS. On prereduced and on polished surfaces, O2 reduction is limited by the mass transport in the solution. On passivated surfaces, the oxygen reduction is not limited by the mass transport in the solution. It may be due to a limited access of oxygen to the metal surface and/or to a modification of the electronic conductivity of the oxide film. In both cases, about 10% and 20% of oxygen is reduced to hydrogen peroxide. On passivated surfaces, O2 reduction occurs simultaneously with the reduction of ferric oxide

Acces aux logiciels CBDS (Circuit Board Design System) sur une console graphique IBM 5080

SIGLECNRS RP 252 (343) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Essai de placement et de routage d'une carte de circuit imprime mixte, circuits integres conventionnels et composants montes en surface (CMS) avec CBDS (Circuit Board Design System)

SIGLECNRS RP 252 (346) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Detection and quantification of the toxic microalgae Karenia brevis using lab on a chip mRNA sequence-based amplification

Now and again, the rapid proliferation of certain species of phytoplankton can give rise to Harmful Algal Blooms, which pose a serious threat to marine life and human health. Current methods of monitoring phytoplankton are limited by poor specificity or by the requirement to return samples to a highly resourced, centralised lab. The Lab Card is a small, microfluidic cassette which, when used in tandem with a portable Lab Card Reader can be used to sensitively and specifically quantify harmful algae in the field, from nucleic acid extracts using RNA amplification; a sensitive and specific method for the enumeration of potentially any species based on their unique genetic signatures. This study reports the culmination of work to develop a Lab Card-based genetic assay to quantify the harmful algae Karenia brevis using mRNA amplification by the Nucleic Acid Sequence Based Amplification (NASBA) method. K. brevis cells were quantified by amplification of the rbcL gene transcript in nucleic acid extracts of K. brevis cell samples. A novel enzyme dehydration and preservation method was combined with a pre-existing reagent Gelification method to prepare fully preserved Lab Cards with a shelf-life of at least six weeks prior to use. Using an internal control (IC), the Lab Card-based rbcL NASBA was demonstrated for the quantification of K. brevis from cell extracts containing between 50 and 5000 cells. This is the first demonstration of quantitation of K. brevis using IC-NASBA on a Lab Card

Real-time isothermal RNA amplification of toxic marine microalgae using preserved reagents on an integrated microfluidic platform

Quantitation of specific RNA sequences is a useful technique in marine biology that can elucidate cell abundance, speciation and viability, especially for early detection of harmful algal blooms. We are thus developing an integrated microfluidic system for cell concentration and lysis, RNA extraction/purification and quantitative RNA detection for environmental applications. The portable system is based on a microfluidic cartridge, or “lab-card”, using a low-cost injection moulded device, with a laminated lid. Here we present real-time isothermal RNA amplification using reagent master-mixes preserved on-chip in a gel at 4 °C for up to eight months. We demonstrate quantitation by reference to an internal control in a competitive assay with 500 cell equivalents of the toxic microalga Karenia brevis. Annealing of primers, amplification at 41 °C and real-time fluorescence detection of the internal control and target using sequence-specific molecular beacons were all performed on-chi