Assessing Humoral Immuno-Inflammatory Pathways Associated with Respiratory Failure in COVID-19 Patients

All severe cases of SARS-CoV-2 infections are characterized by a high risk of disease progression towards ARDS, leading to a bad outcome. Respiratory symptoms in COVID-19 patients often do not correspond to disease's worsening. In our sample, median age was 74 years (72-75) and 54% were men. The median period of hospitalization was 9 days. Firstly, we observed a significant asynchronous trend of neutrophil-to-lymphocyte ratio (NLR) and C-reactive protein (CRP) in 764 selected among 963 patients, who were consecutively recruited in two hospitals (Cannizzaro, S. Marco) in Catania, Italy. NLR values in deceased patients showed an increase from baseline over time. By contrast, CRP tended to fall from baseline to median day of hospitalization in all three subgroups, but steeply increased at the end of hospitalization only in ICU-admitted patients. Then, we evaluated the relationships between NLR and CRP as continuous variables with PaO₂/FiO₂ ratio (P/F). NLR was an independent predictor of mortality (HR: 1.77, p < 0.0001), while ICU admission was more significantly associated with CRP (HR: 1.70, p < 0.0001). Finally, age, neutrophils, CRP, and lymphocytes are significantly and directly linked to P/F, while the influence of inflammation on P/F, reflected by CRP, was also mediated by neutrophils.

X-ray-imaging spectrometer (XRIS) for studies of residual kinetic energy and low-mode asymmetries in inertial confinement fusion implosions at OMEGA (invited)

A system of x-ray imaging spectrometer (XRIS) has been implemented at the OMEGA Laser Facility and is capable of spatially and spectrally resolving x-ray self-emission from 5 to 40 keV. The system consists of three independent imagers with nearly orthogonal lines of sight for 3D reconstructions of the x-ray emission region. The distinct advantage of the XRIS system is its large dynamic range, which is enabled by the use of tantalum apertures with radii ranging from 50 μm to 1 mm, magnifications of 4 to 35×, and image plates with any filtration level. In addition, XRIS is capable of recording 1-100's images along a single line of sight, facilitating advanced statistical inference on the detailed structure of the x-ray emitting regions. Properties such as P0 and P2 of an implosion are measured to 1% and 10% precision, respectively. Furthermore, T_e can be determined with 5% accuracy.

The phase-2 particle x-ray temporal diagnostic for simultaneous measurement of multiple x-ray and nuclear emission histories from OMEGA implosions (invited)

Electron-temperature (T_e) measurements in implosions provide valuable diagnostic information, as T_e is negligibly affected by residual flows and other non-thermal effects unlike ion-temperature inferred from a fusion product spectrum. In OMEGA cryogenic implosions, measurement of T_e(t) can be used to investigate effects related to time-resolved hot-spot energy balance. The newly implemented phase-2 Particle X-ray Temporal Diagnostic (PXTD) utilizes four fast-rise (∼15 ps) scintillator-channels with distinct x-ray filtering. Titanium and stepped aluminum filtering were chosen to maximize detector sensitivity in the 10-20 keV range, as it has been shown that these x rays have similar density and temperature weighting to the emitted deuterium-tritium fusion neutrons (DTn) from OMEGA Cryo-DT implosions. High quality data have been collected from warm implosions at OMEGA. These data have been used to infer spatially integrated T_e(t) with <10% uncertainty at peak emission. Nuclear and x-ray emission histories are measured with 10 ps relative timing uncertainty for x rays and DTn and 12 ps for x rays and deuterium-He3 protons (D³Hep). A future upgrade to the system will enable spatially integrated T_e(t) with 40 ps time-resolution from cryogenic DT implosions.

Should reduction of increased short-term blood pressure variability be a target of antihypertensive therapy?

It has long been known that blood pressure (BP) is characterized by marked short-term fluctuations occurring within a 24-h period and also by long-term oscillations occurring over more prolonged periods of time. An increased short-term blood pressure variability (BPV) appears to importantly contribute to target organ damage and to the enhanced cardiovascular risk of hypertensive patients, over and above the effect of an increase in mean BP levels. Reducing 24-h mean BP is the main aim of antihypertensive therapy, but initial data are available that additional cardiovascular protection can be achieved by reducing BPV. However, to definitively prove the prognostic role of short-term BPV and the need for its control by treatment, evidence is still needed from intervention trials aimed at demonstrating that by reducing BPV through administration of antihypertensive drugs, a reduction in organ damage and in the rate of cardiovascular events can be obtained.

A multi-channel x-ray temporal diagnostic for measurement of time-resolved electron temperature in cryogenic deuterium-tritium implosions at OMEGA

Electron-temperature (T_e) measurements in implosions provide valuable diagnostic information, as T_e is unaffected by residual flows and other non-thermal effects unlike ion temperature inferred from a fusion product spectrum. In OMEGA cryogenic implosions, measurement of T_e(t) can be used to investigate effects related to time-resolved hot-spot energy balance. The proposed diagnostic utilizes five fast-rise (∼15 ps) scintillator channels with distinct x-ray filtering. Titanium and stepped aluminum filtering were chosen to maximize detector sensitivity in the 10 keV-20 keV range, as it has been shown that these x rays have similar density and temperature weighting to the emitted deuterium-tritium fusion neutrons. Initial data collected using a prototype nosecone on the existing neutron temporal diagnostic demonstrate the validity of this diagnostic technique. The proposed system will be capable of measuring spatially integrated T_e(t) with 20 ps time resolution and <10% uncertainty at peak emission in cryogenic DT implosions.

Relationship of choroidal thickness with pulsatile hemodynamics in essential hypertensive patients

Controversy exists about the association of choroidal thickness (CTh) with blood pressure (BP) values. There is some evidence suggesting that central hemodynamics changes are associated with microvascular disease. Our study was aimed to assess the relationships between CTh and clinic and 24‐h BP and between CTh and estimated 24‐h aortic pulse pressure (aPP), 24‐h aortic systolic BP (aSBP), and 24‐h aortic augmentation index (aAIx) in a group of hypertensive patients. We enrolled 158 hypertensive subjects (mean age 48 ± 13 years) all of which underwent evaluation of the choroidal district by Swept‐Source optical coherence tomography (SS‐OCT) and 24‐h BP monitoring, in order to measure peripheral BP and to estimate central hemodynamic parameters. Inverse significant correlations of clinic PP, 24‐h aPP, 24‐h aSBP, and 24‐h aAIx with thicknesses of central ring, inner ring, and outer ring of the choroid and its overall average were found. The strongest of these correlations was that relating 24‐h aPP with overall average choroidal thickness (r = −.531; P < .001). When we divided the study population in subjects with 24‐h aPP above and below the median value (35 mm Hg), CTh were thinner in subjects with higher values of 24‐aPP as compared to those with lower ones, even after adjustment for age, and other potential confounders. The relationships of CTh with 24‐h aPP remained significant also taking into account the effects of various covariates in linear multiple regression analyses. Our findings support the concept of a cross‐talk between macro‐ and microcirculation.

SAT0231 MULTIDIRECTIONAL DYSFUNCTION OF THE IMMUNE RESPONSE IN SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Systemic lupus erythematosus (SLE) is a multi-organ immune-mediated disease characterised by autoimmunity. Dysfunction in immune tolerance towards allergens and protection from infections has less been studied. Human leukocyte antigen (HLA) genotype affects the risk of developing SLE. Little is known on the role of HLA in shaping SLE phenotype.

Objectives:

To test for potential associations among active SLE, occurrence of infections and hypersensitivity reactions (HyR) at a clinical level and assess whether these events segregate with patients’ HLA-DRB1 typing.

Methods:

224 patients with SLE were prospectively followed up over the course of 1267 consecutive visits with a median interval of five months between each visit. HyR occurring within one month before or after each visit and occurrence of at least one infection leading to antimicrobial treatment and/or absence from work in the interval between each visit were recorded. Disease activity was estimated through the systemic lupus erythematosus disease activity index 2000 (SLEDAI-2K). Remission was surrogated by the Lupus Low Disease Activity State (LLDAS). Demographics and general disease features including a previous history of allergy were retrospectively assessed. HLA-DRB1 genotype was obtained from 188 patients. Data are expressed as median [interquartile range], unless otherwise specified.

Results:

Incidence rates for HyR and infections were 80/1000 person-years and 45/100 person-years. Culprit agents for HyR were drugs in 61% of cases, inhalants, food or other allergens in the remainder 42%. Most frequent sites for infections were the airways (55%), skin and mucosae (16%), the genital and/or urinary tracts (14%) and the gastrointestinal tract (7%). LLDAS was inversely associated with HyR (χ2=20.912; p<0.0001) or infections (χ2=8.234; p=0.005). patients with a recent HyR had a shorter disease duration (9 [2-15] vs 13 [8-22] years; p=0.006) and higher SLEDAI-2K scores (4 [3.5-11] vs 3 [2-4]; p<0.001) compared to patients without recent HyR. HyR were more frequently observed close to recent infections (χ2=15.509; p<0.0001). Patients with HLA-DRB1*11:01 (n=28/188) had more frequently a history of allergy than patients with other HLA-DRB1 genotypes (χ2=4.944; p=0.035). Among patients with at least four prospective visits, HLA-DRB1*11:01 carriers reported a recent infection more frequently (25% [13-40%] vs 14% [0-29%]; p=0.044) and HLA-DRB1*07:01 carriers less frequently (0% [0-17%] vs 18% [11-33%]; p=0.026) compared to patients with other HLA-DRB1 genotypes.

Conclusion:

These data suggest that immune dysfunction in SLE not only affects tolerance to self antigens but also antimicrobial and allergic responses and that genetically determined HLA-restricted mechanisms of antigen presentation might influence the shape of this dysfunctional immune response in patients with SLE.

References:

[1]Teruel M et al. Curr Opin Rheumatol, 2016

[2]Sequeira JF et al., Lupus, 1993

[3]Danza A et al, Lupus, 2013

[4]Park H et al., Allergy Asthma Immunol Res, 2012

[5]Quiralte J et al., J Allergy Clin Immunol, 1999

Disclosure of Interests:

Giuseppe Alvise Ramirez: None declared, Andrea Sorce: None declared, Benedetta Allegra Mazzi: None declared, Luca Moroni: None declared, Emanuel Della Torre: None declared, Giselda Colombo: None declared, Mona-Rita Yacoub: None declared, Enrica Bozzolo: None declared, Lorenzo Dagna Grant/research support from: The Unit of Immunology, Rheumatology, Allergy and Rare Diseases (UnIRAR) received unresctricted research/educational grants from Abbvie, Bristol-Myers Squibb, Celgene, Janssen, Merk Sharp & Dohme, Mundipharma Pharmaceuticals, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Consultant of: Prof Lorenzo Dagna received consultation honoraria from Abbvie, Amgen, Biogen, Bristol-Myers Squibb, Celltrion, Novartis, Pfizer, Roche, Sanofi-Genzyme, and SOBI., Angelo Manfredi: None declared

A rate-doubled 10-GHz fiducial comb generator for precision optical timing calibration

Solid-state optical fiducial timing pulse generators provide a convenient and accurate method to include timing fiducials in a streak-camera image for time-base correction. Current commercially available vertical-cavity surface-emitting lasers (VCSELs) emitting in the visible range can be amplitude modulated up to 5 GHz. An optically passive method is utilized to interleave a time-delayed path of the 5-GHz pulsed light with itself, producing a 10-GHz pulsed fiducial, or comb. Comb pulse rates at 0.5, 1.0, and 2.5 GHz can also be selected. The instrument presented is a self-contained and portable generator with primary use for streak-camera temporal calibration. Applications can also be extended to many other optical timing needs. The VCSEL output is fiber optic coupled at a wavelength of 680 nm (visible red) with a nearly Gaussian pulse shape. The peak power of each ∼50-ps full width at half maximum (FWHM) comb pulse at 5-GHz operation, or picket, is approximately 5 mW. The low phase noise of the internal microwave modulation drive source provides low pulse to pulse jitter. An external reference frequency standard can be utilized to synchronize the output to external timing equipment. A selectable internal reference frequency crystal oscillator is incorporated for stand-alone operation.

First measurements of remaining shell areal density on the OMEGA laser using the Diagnostic for Areal Density (DAD)

A glass Cherenkov detector, called the Diagnostic for Areal Density (DAD), has been built and implemented at the OMEGA laser facility for measuring fusion gammas above 430 keV, from which remaining shell ⟨ρR⟩ _abl can be determined. A proof-of-principle experiment is discussed, where signals from a surrogate gas Cherenkov detector are compared with reported values from the wedge range filter and charged particle spectrometer and found to correlate strongly. The design of the more compact port-based DAD diagnostic and results from the commissioning shots are then presented. Once absolutely calibrated, the DAD will be capable of reporting remaining shell ⟨ρR⟩ _abl for plastic and glass capsules within minutes of a shot and with potentially higher precision than existing techniques.

Absolute calibration of the OMEGA streaked optical pyrometer for temperature measurements of compressed materials

Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) and temperatures (T > 0.5 eV). This paper reports on the absolute calibration of the streaked optical pyrometer (SOP) at the Omega Laser Facility. The wavelength-dependent system response was determined by measuring the optical emission from a National Institute of Standards and Technology-traceable tungsten-filament lamp through various narrowband (40-nm-wide) filters. The integrated signal over the SOP's ∼250-nm operating range is then related to that of a blackbody radiator using the calibrated response. We present a simple closed-form equation for the brightness temperature as a function of streak-camera signal derived from this calibration. Error estimates indicate that brightness temperature can be inferred to a precision of <5%.

Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments-a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ∼16 m to a streak camera in a well-shielded location. An ∼200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ∼40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

Comparative analysis of the structure of temporomandibular joint in human and rabbit

In order to increase knowledge on the morphology and structure of the articular disc of the TMJ for a better understanding of the functional role of the same, it proceeded with an investigation on histological samples in the block of 'TMJ and periarticular tissues of adult rabbits and human fetuses at different stage of development.