Pyridostigmine reduces mortality of patients with severe SARS-CoV-2 infection: A phase 2/3 randomized controlled trial.

BACKGROUND: Respiratory failure in severe coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Acetylcholine (ACh) reduces systemic inflammation in experimental bacterial and viral infections. Pyridostigmine increases the half-life of endogenous ACh, potentially reducing systemic inflammation. We aimed to determine if pyridostigmine decreases a composite outcome of invasive mechanical ventilation (IMV) and death in adult patients with severe COVID-19. METHODS: We performed a double-blinded, placebo-controlled, phase 2/3 randomized controlled trial of oral pyridostigmine (60 mg/day) or placebo as add-on therapy in adult patients admitted due to confirmed severe COVID-19 not requiring IMV at enrollment. The primary outcome was a composite of IMV or death by day 28. Secondary outcomes included reduction of inflammatory markers and circulating cytokines, and 90-day mortality. Adverse events (AEs) related to study treatment were documented and described. RESULTS: We recruited 188 participants (94 per group); 112 (59.6%) were men; the median (IQR) age was 52 (44-64) years. The study was terminated early due to a significant reduction in the primary outcome in the treatment arm and increased difficulty with recruitment. The primary outcome occurred in 22 (23.4%) participants in the placebo group vs. 11 (11.7%) in the pyridostigmine group (hazard ratio, 0.47, 95% confidence interval 0.24-0.9; P = 0.03). This effect was driven by a reduction in mortality (19 vs. 8 deaths, respectively). CONCLUSION: Our data indicate that adding pyridostigmine to standard care reduces mortality among patients hospitalized for severe COVID-19.

Zinc and selenium supplementation on treated HIV-infected individuals induces changes in body composition and on the expression of genes responsible of naïve CD8+ T cells function.

Background and aim: Deficiency of zinc and selenium is common in persons living with human immunodeficiency virus (PLWHIV) and has been associated with the development of non-AIDS related comorbidities, impaired immune system function and mortality. Micronutrient supplementation on long-term-treated PLWHIV could bring potential clinical and immunological benefits improving their health status and quality of life. The aim of the present study is to analyze the effect of zinc and selenium supplementation on body composition, bone mineral density, CD4+ T-cell counts, metabolic profile and immune system status on clinical stable PLWHIV on long-term antiretroviral therapy (ART). Methods: This is a randomized pilot clinical trial in which we recruited 60 PLWHIV on ART who were assigned to the intervention groups: zinc (30 mg of zinc gluconate), selenium (200 µg of selenium yeast), zinc + selenium (same doses and presentations) or to a control group (without nutritional supplementation) who received supplementation during 6 months. Primary outcome was defined as changes in body composition (weight, muscle and fat mass and bone mineral density) and secondary outcomes as changes in biochemical and immunological parameters (CD4+ T-cell count, cholesterol, glucose, triglycerides and seric zinc and selenium seric concentrations) before and after supplementation. Peripheral blood mononuclear cells (PBMCs) of one individual of each intervention group were analyzed for single cell transcriptomics before and after supplementation. Results: BMI (p = 0.03), fat mass (p = 0.03), and trunk fat (p = 0.01) decreased after 6 months of selenium supplementation. No changes were observed for cholesterol, glucose or triglycerides after supplementation (p > 0.05 in all cases). CD4+ T cells percentage increased after 6 months of selenium supplementation (p = 0.03). On the transcriptome analysis, zinc and selenium supplementation induced changes on de expression of genes associated with the function of naive and memory CD8+ T-cells (p < 0.05 in all cases). Conclusion: Zinc and selenium supplementation could represent a complementary intervention that may improve the health status and immune response of treated PLWHIV.

Antibody and Memory B-Cell Immunity in a Heterogeneously SARS-CoV-2-Infected and -Vaccinated Population.

Global population immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is accumulating through heterogeneous combinations of infection and vaccination. Vaccine distribution in low- and middle-income countries has been variable and reliant on diverse vaccine platforms. We studied B-cell immunity in Mexico, a middle-income country where five different vaccines have been deployed to populations with high SARS-CoV-2 incidences. Levels of antibodies that bound a stabilized prefusion spike trimer, neutralizing antibody titers, and memory B-cell expansion correlated with each other across vaccine platforms. Nevertheless, the vaccines elicited variable levels of B-cell immunity, and the majority of recipients had undetectable neutralizing activity against the recently emergent omicron variant. SARS-CoV-2 infection, experienced before or after vaccination, potentiated B-cell immune responses and enabled the generation of neutralizing activity against omicron and SARS-CoV for all vaccines in nearly all individuals. These findings suggest that broad population immunity to SARS-CoV-2 will eventually be achieved but by heterogeneous paths. IMPORTANCE The majority of studies on SARS-CoV-2 vaccine-elicited immunity and immune evasion have focused on single vaccines corresponding to those distributed in high-income countries. However, in low- and middle-income countries, vaccine deployment has been far less uniform. It is therefore important to determine the levels of immunity elicited by vaccines that have been deployed globally. Such data should help inform policy. Thus, this paper is very much a "real-world" study that focuses on a middle-income country, Mexico, in which five different vaccines based on mRNA, adenovirus, and inactivated-virus platforms have been extensively deployed, while (as documented in our study) SARS-CoV-2 variants with increasing degrees of immune evasiveness have propagated in the Mexican population, culminating in the recent emergence of B.1.1.529 (omicron).

Lymph nodes from HIV-infected individuals harbor mature dendritic cells and increased numbers of PD-L1+ conventional dendritic cells.

The immune response induced by dendritic cells (DC) during the HIV infection has been of remarkable interest because of the therapeutic potential of DC for vaccine development. However, their beneficial or detrimental contribution in HIV infection remains unclear. The activation state of DC in lymph nodes (LN) is essential to induce T cell responses against HIV. In the present study, we characterized the immunophenotype and function of conventional (cDC) and plasmacytoid (pDC) dendritic cells from peripheral blood (PB) and LN of HIV(+) individuals. We observed that the frequency of PB pDC was decreased and exhibited an immature phenotype; whereas in the LN, activated pDC accumulated (CD40(+) and CD83(+)). In addition, the frequency of PB cDC from HIV(+) individuals was decreased and exhibited an immature phenotype, whereas LN harbored activated and mature cDC (CD40(+), CD83(+), CD80(+) and CD86(+)). However, an increased number of PD-L1(+) cDC was also observed in the LN. Moreover, pDC and cDC were able to produce inflammatory cytokines (IFN-α, TNF-α and IL-12) after TLR stimulation. These findings suggests that LN cDC expressing PD-L1 from HIV(+) individuals may negatively impact the generation of HIV-specific T cells and that DC might be contributing to tissue chronic immune activation.