Writing Committee for the REMAP-CAP Investigators IMPORTANCE The evidence for benefit of convalescent plasma for critically ill patients with COVID-19 is inconclusive.OBJECTIVE To determine whether convalescent plasma would improve outcomes for critically ill adults with COVID-19. DESIGN, SETTING, AND PARTICIPANTSThe ongoing Randomized, Embedded, Multifactorial, Adaptive Platform Trial for Community-Acquired Pneumonia (REMAP-CAP) enrolled and randomized 4763 adults with suspected or confirmed COVID-19 between March 9, 2020, and January 18, 2021, within at least 1 domain; 2011 critically ill adults were randomized to open-label interventions in the immunoglobulin domain at 129 sites in 4 countries. Follow-up ended on April 19, 2021. INTERVENTIONSThe immunoglobulin domain randomized participants to receive 2 units of high-titer, ABO-compatible convalescent plasma (total volume of 550 mL ± 150 mL) within 48 hours of randomization (n = 1084) or no convalescent plasma (n = 916). MAIN OUTCOMES AND MEASURESThe primary ordinal end point was organ support-free days (days alive and free of intensive care unit-based organ support) up to day 21 (range, −1 to 21 days; patients who died were assigned -1 day). The primary analysis was an adjusted bayesian cumulative logistic model. Superiority was defined as the posterior probability of an odds ratio (OR) greater than 1 (threshold for trial conclusion of superiority >99%). Futility was defined as the posterior probability of an OR less than 1.2 (threshold for trial conclusion of futility >95%). An OR greater than 1 represented improved survival, more organ support-free days, or both. The prespecified secondary outcomes included in-hospital survival; 28-day survival; 90-day survival; respiratory support-free days; cardiovascular support-free days; progression to invasive mechanical ventilation, extracorporeal mechanical oxygenation, or death; intensive care unit length of stay; hospital length of stay; World Health Organization ordinal scale score at day 14; venous thromboembolic events at 90 days; and serious adverse events. RESULTS Among the 2011 participants who were randomized (median age, 61 [IQR, 52 to 70] years and 645/1998 [32.3%] women), 1990 (99%) completed the trial. The convalescent plasma intervention was stopped after the prespecified criterion for futility was met. The median number of organ support-free days was 0 (IQR, -1 to 16) in the convalescent plasma group and 3 (IQR, -1 to 16) in the no convalescent plasma group. The in-hospital mortality rate was 37.3% (401/1075) for the convalescent plasma group and 38.4% (347/904) for the no convalescent plasma group and the median number of days alive and free of organ support was 14 (IQR, 3 to 18) and 14 (IQR, 7 to 18), respectively. The median-adjusted OR was 0.97 (95% credible interval, 0.83 to 1.15) and the posterior probability of futility (OR <1.2) was 99.4% for the convalescent plasma group compared with the no convalescent plasma group. The treatment effects were consistent across the primary outcome and the 11...

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Parkia javanica is a well-known ethno-botanical plant of the north-east region of India. Ethnic communities of the region use several parts, including fruits, of this plant for the treatment of various ailments like diarrhoea, dysentery, cholera, food poisoning etc. In addition fruits are consumed by the local tribes of the north-east as food supplements. With this background we have performed chemical characterisation, and investigated the antimicrobial and antibiofilm potentiality of ethyl acetate fraction of Parkia javanica fruit extract (PJE) against model biofilm-causing microorganism Pseudomonas aeruginosa. PJE was initially prepared from fruit extract, and assayed by IR and UV spectroscopy and HPLC to confirm the presence of compounds. HPLC and NMR analysis reveals that PJE contains flavone compounds baicalein, quercetin and chrysin. PJE, baicalein, quercetin and chrysin were then tested for antimicrobial and antibiofilm activity against P. aeruginosa. PJE showed very significant antimicrobial activity against P. aeruginosa wherein the minimum inhibitory concentration was found at 180 mg mL À1. Interestingly, the antibiofilm study illustrates that minimum concentration of PJE (30 mg mL À1 ) exhibited maximum activity whereas maximum concentration of PJE (90 mg mL À1 ) exhibited minimum antibiofilm activity. It was also observed that compounds baicalein, quercetin and chrysin separately show lower to moderate antibiofilm activity in comparison to PJE. Molecular docking study indicates that baicalein, quercetin and chrysin have good binding affinity with bacterial quorum sensing and motility associated proteins. Furthermore, we have also observed that in comparison with higher concentration, lower concentration of PJE exhibited better attenuation in swarming motility, secretion of proteases and virulence factors like pyoverdin and pyocyanin. AFM study reveals that aggregates in PJE are smaller in size at low concentrations than at higher concentrations. Observations in the present study suggest that PJE as a whole shows higher antibiofilm activity at low concentration whereas individual compounds have comparatively lower antibiofilm activity. This validates the phytomedicinal significance of Parkia javanica against bacterial biofilms.

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Rationale Lymphopenia is common in severe coronavirus disease (COVID-19), yet the immune mechanisms are poorly understood. As inflammatory cytokines are increased in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we hypothesized a role in contributing to reduced T-cell numbers. Objectives We sought to characterize the functional SARS-CoV-2 T-cell responses in patients with severe versus recovered, mild COVID-19 to determine whether differences were detectable. Methods Using flow cytometry and single-cell RNA sequence analyses, we assessed SARS-CoV-2-specific responses in our cohort. Measurements and Main Results In 148 patients with severe COVID-19, we found lymphopenia was associated with worse survival. CD4 + lymphopenia predominated, with lower CD4 + /CD8 + ratios in severe COVID-19 compared with patients with mild disease ( P < 0.0001). In severe disease, immunodominant CD4 + T-cell responses to Spike-1 (S1) produced increased in vitro TNF-α (tumor necrosis factor-α) but demonstrated impaired S1-specific proliferation and increased susceptibility to activation-induced cell death after antigen exposure. CD4 + TNF-α + T-cell responses inversely correlated with absolute CD4 + counts from patients with severe COVID-19 ( n = 76; R = −0.797; P < 0.0001). In vitro TNF-α blockade, including infliximab or anti-TNF receptor 1 antibodies, strikingly rescued S1-specific CD4 + T-cell proliferation and abrogated S1-specific activation-induced cell death in peripheral blood mononuclear cells from patients with severe COVID-19 ( P < 0.001). Single-cell RNA sequencing demonstrated marked downregulation of type-1 cytokines and NFκB signaling in S1-stimulated CD4 + cells with infliximab treatment. We also evaluated BAL and lung explant CD4 + T cells recovered from patients with severe COVID-19 and observed that lung T cells produced higher TNF-α compared with peripheral blood mononuclear cells. Conclusions Together, our findings show CD4 + dysfunction in severe COVID-19 is TNF-α/TNF receptor 1–dependent through immune mechanisms that may contribute to lymphopenia. TNF-α blockade may be beneficial in severe COVID-19.

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(which was not peer-reviewed) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.

Context: Visceral leishmaniasis is a protozoan disease caused by Leishmania donovani parasite. The genus Sterculia (Malvaceae) possesses ethnobotanical potential against this protozoan infection. Objective: Determining the potential role of methanol bark extracts from Sterculia villosa Roxb (SVE) and its phytoconstituents against Leishmania donovani promastigotes. Materials and methods: SVE was analysed by TLC, UV–Vis, IR spectroscopy and biochemical assays. Antileishmanial potential of SVE (0.5–130 μg/mL for 72 h) was characterized by MTT assay. Fluorescent microscopy was performed to validate the IC50 dose. To determine the effect of SVE on promastigotes, reactive oxygen species (ROS) and superoxide generation, lipid peroxidation and DNA fragmentation assays were performed. Molecular aggregation of compounds was determined by atomic force microscopy (AFM). Extent of cytotoxicity of SVE at IC50 dose was determined against RAW 264.7 macrophages, peritoneal macrophages and murine RBCs. In vivo cytotoxicity of SVE was evaluated in BALB/c mice. Result: SVE exhibited reverse dose dependent antileishmanial activity when 130–0 μg/mL doses were tested against promastigotes. The IC50 and IC70 values were found to be 17.5 and 10 μg/mL, respectively. SVE at IC50 dose demonstrated elevated level of ROS, superoxide, lipid peroxidation and DNA fragmentation against promastigotes with no cytotoxicity. AFM analysis suggested increasing size of molecular aggregation (31.3 nm < 35.2 nm < 2.93 μm) with increase in concentration (10 μg < 17.5 μg < 130 μg). Discussion and conclusions: The study elucidates the antileishmanial potential of SVE against Leishmania donovani promastigotes by exerting oxidative stress and DNA damage. In sum, SVE can be explored as an immunotherapeutic candidate against leishmaniasis and other infectious diseases.