Cardiac Adipose Tissue Volume assessed by Computed Tomography is a specific and independent Predictor of Early Mortality and Critical Illness in COVID-19 in type 2-Diabetic Patients (preprint)

Background Patients with type 2-diabetes mellitus (T2D), are characterized by visceral and ectopic adipose tissue expansion, leading to systemic chronic low-grade inflammation. As visceral adiposity is associated with severe COVID-19 irrespective of obesity, we aimed to evaluate and compare the predictive value for early intensive care or death of three fat depots (cardiac, visceral and subcutaneous) using computed tomography (CT) at admission for COVID-19 in consecutive patients with and without T2D.Methods Two hundred and two patients admitted for COVID-19 were retrospectively included between February and June 2020 and distributed in two groups: T2D or non-diabetic controls. Chest CT with cardiac (CATi), visceral (VATi) and subcutaneous adipose tissue (SATi) volume measurements were performed at admission. The primary endpoint was a composite outcome criteria including death or ICU admission at day 21 after admission. Threshold values of adipose tissue components predicting adverse outcome were determined.Results One hundred and eight controls (median age: 76[IQR:59–83], 61% male, median BMI: 24[22–27]) and ninety-four T2D patients (median age: 70[IQR:61–77], 70% male, median BMI: 27[24–31]), were enrolled in this study. At day 21 after admission, 42 patients (21%) had died from COVID-19, 48 (24%) required intensive care and 112 (55%) were admitted to a conventional care unit (CMU). In T2D, CATi was associated with early death or ICU independently from age, sex, BMI, dyslipidemia, CRP and coronary calcium (CAC). (p = 0.005). Concerning T2D patients, the cut-point for CATi was > 100 mL/m² with a sensitivity of 0.83 and a specificity of 0.50 (AUC = 0.67, p = 0.004) and an OR of 4.71 for early ICU admission or mortality (p = 0.002) in the fully adjusted model. Other adipose tissues SATi or VATi were not significantly associated with early adverse outcomes. In control patients, age and male sex (OR = 1.03, p = 0.04) were the only predictors of ICU or death.Conclusions Cardiac adipose tissue volume measured in CT at admission was independently predictive of early intensive care or death in T2D patients with COVID-19 but not in non-diabetics. Such automated CT measurement could be used in routine in diabetic patients presenting with moderate to severe COVID-19 illness to optimize individual management and prevent critical evolution.

BNT162b2 vaccine-induced humoral and cellular responses against SARS-CoV-2 variants in Systemic Lupus Erythematosus (preprint)

Objectives: Our aims were to evaluate Systemic Lupus Erythematosus (SLE) disease activity and SARS-CoV-2 specific immune responses after BNT162b2 vaccination. Methods: In this prospective study, disease activity and clinical assessments were recorded from the first dose of vaccine, until day 15 after the second dose in 126 SLE patients. SARS-CoV-2 antibody responses were measured against wild-type spike antigen while serum-neutralizing activity was assessed against the SARS-CoV-2 historical strain and variants of concerns (VOCs). Vaccine-specific T-cell responses were quantified by Interferon (IFN)-gamma; release assay after the second dose. Results: BNT162b2 was well tolerated and no statistically significant variations of BILAG and SLEDAI scores were observed throughout the study in SLE patients with active and inactive disease at baseline. Mycophenolate Mofetil (MMF) and Methotrexate (MTX) treatments were associated with drastically reduced BNT162b2 antibody-response (beta=-78; p=0.007, beta=-122; p<0.001, respectively). Anti-spike antibody response was positively associated with baseline total IgG serum levels, naive B cell frequencies (beta=2; p=0.018, beta=2.5; p=0.003) and SARS-CoV-2-specific T cell response (r=0.462; p=0.003). In responders, serum neutralization activity decreased against VOCs bearing the E484K mutation but remained detectable in a majority of patients. Conclusion: MMF, MTX and poor baseline humoral immune status, particularly: low naive B cell frequencies, are independently associated with impaired BNT162b2 mRNA antibody response, delineating SLE patients who might need adapted vaccine regimens and follow-up.

LOX-1+ immature neutrophils predict severe COVID-19 patients at risk of thrombotic complications (preprint)

Rational: Lymphopenia and neutrophil/lymphocyte ratio may have prognostic value in coronavirus disease 2019 (COVID-19) severity. Objective: We sought to investigate the representation of neutrophil subsets in severe and critical COVID-19 patients based on Intensive Care Units (ICU) and non-ICU admission. Methods: We developed a multi-parametric neutrophil profiling strategy based on known neutrophil markers to distinguish COVID-19 phenotypes in critical and severe patients. Results: Our results showed that 80 percent of ICU patients develop strong myelemia with CD10-CD64+ immature neutrophils. Cellular profiling revealed two distinct neutrophil subsets expressing either the lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) or the Interleukin-3 receptor alpha (CD123), both significantly overrepresented in ICU patients compared to non-ICU patients. The proportion of LOX-1-expressing immature neutrophils positively correlated with clinical severity, with the cytokine storm (IL-1{beta}, IL-6, IL-8, TNF), and with intravascular coagulation. Importantly, high proportions of LOX-1+-immature neutrophils are associated with high risks of severe thrombosis. Conclusions: Together these data suggest that point of care enumeration of LOX-1-immature neutrophils might help distinguish patients at risk of thrombosis complication and most likely to benefit from intensified anticoagulant therapy.

Rational design of a new class of protease inhibitors for the potential treatment of coronavirus diseases (preprint)

The main protease, Mpro, of SARSCoV2 is a key protein in the coronavirus life cycle and a major drug target. Based on crystal structures of SARSCoV2 Mpro complexed with peptidomimetic inhibitors, we recognized a structural motif shared with approved inhibitors of hepatitis C virus protease. Initial tests showed that several HCV protease inhibitors could indeed also inhibit Mpro. Based on the identified molecular scaffolds we designed a new generation of ketoamide-based Mpro inhibitors with a preorganized backbone conformation. One of the designed inhibitors, ML1000, shows particularly high affinity towards Mpro and inhibits SARSCoV2 viral replication in human cells at sub-micromolar concentrations. Our findings identify ML1000 as a promising new scaffold for the development of anti-coronavirus drugs.

Pre-COVID-19 humoral immunity to common coronaviruses does not confer cross-protection against SARS-CoV-2 (preprint)

It is currently unknown whether acquired immunity to common alpha- and beta-coronaviruses provides cross-protection against SARS-CoV-2. In this study, we found that certain patient sera and intravenous immunoglobulins (IVIG) collected prior to the COVID-19 outbreak were cross-reactive to SARS-CoV-2 full-length Spike, S2 domain, and nucleoprotein. However, their presence did not translate into neutralizing activity against SARS-CoV-2 in vitro. Importantly, we detected serum IgG reactivity to common coronaviruses in the early sera of patients with severe COVID-19 before the appearance of anti-SARS-CoV-2 antibodies. Collectively, the results of our study indicate that pre-existing immunity to common coronaviruses does not confer cross-protection against SARS-CoV-2 in vivo.

Low rate of daily smokers in patients with symptomatic COVID-19 (preprint)

Background: Identification of prognostic factors in COVID-19 remains a global challenge. The role of smoking is still controversial. Objective: To evaluate the rate of daily smokers in patients with COVID-19. Methods: COVID-19 in-and outpatients from a large French university hospital were systematically interviewed for their smoking status, use of e-cigarette and nicotinic substitutes. The rates of daily smokers in in-and outpatients were compared to those in the 2019 French general population, after standardization for sex and age. Results: The inpatient group was composed of 340 patients, median age 66 years: 203 men (59.7%) and 137 women (40.3%), median age for both 66 years, with a daily smokers rate of 4.1 % CI95% [2.3-6.9] (5.4% of men, 2.2% of women). The outpatient group was composed of 139 patients, median age 44 years: 62 men (44.6%, median age 43 years), and 77 women (55.4%, median age 44 years). The daily smoker rate was 6.1 % CI 95% [2.7-11.6] (5.1% of men, 6.8% of women). In the 2019 French population, the daily smoker rate was 24.0% (27.5% of men, 20.7% of women). Among inpatients, daily smokers represented 2.2% and 3.4% of the 45 dead patients and of the 29 patients transferred to ICU, respectively. The rate of daily smokers was significantly lower in COVID-19 patients, as compared to that in the French general population after standardization by age and sex, with Standardized Incidence Ratios of 0.24 [0.12-0.48] for outpatients and 0.24 [0.14-0.40] for inpatients. Conclusion: Daily smokers rate in patients with symptomatic COVID-19 is lower as compared to the general population

IgA dominates the early neutralizing antibody response to SARS-CoV-2 (preprint)

A major dogma in immunology has it that the IgM antibody response precedes secondary memory responses built on the production of IgG, IgA and, occasionaly, IgE. Here, we measured acute humoral responses to SARS-CoV-2, including the frequency of antibody-secreting cells and the presence of specific, neutralizing, antibodies in serum and broncho-alveolar fluid of 145 patients with COVID-19. Surprisingly, early SARS-CoV-2-specific humoral responses were found to be typically dominated by antibodies of the IgA isotype. Peripheral expansion of IgA-plasmablasts with mucosal-homing potential was detected shortly after the onset of symptoms and peaked during the third week of the disease. While the specific antibody response included IgG, IgM and IgA, the latter contributed to a much larger extent to virus neutralization, as compared to IgG. However, specific IgA serum levels notably decrease after one month of evolution. These results represent a challenging observation given the present uncertainty as to which kind of humoral response would optimally protect against re-infection, and whether vaccine regimens should consider boosting a potent, although, at least in blood, fading IgA response. One sentence SummaryWhile early specific antibody response included IgG, IgM and IgA, the latter contributed to a much larger extent to virus neutralization.