Clinical Significance of Micronutrient Supplementation in Critically Ill COVID-19 Patients with Severe ARDS.

The interplay between inflammation and oxidative stress is a vicious circle, potentially resulting in organ damage. Essential micronutrients such as selenium (Se) and zinc (Zn) support anti-oxidative defense systems and are commonly depleted in severe disease. This single-center retrospective study investigated micronutrient levels under Se and Zn supplementation in critically ill patients with COVID-19 induced acute respiratory distress syndrome (ARDS) and explored potential relationships with immunological and clinical parameters. According to intensive care unit (ICU) standard operating procedures, patients received 1.0 mg of intravenous Se daily on top of artificial nutrition, which contained various amounts of Se and Zn. Micronutrients, inflammatory cytokines, lymphocyte subsets and clinical data were extracted from the patient data management system on admission and after 10 to 14 days of treatment. Forty-six patients were screened for eligibility and 22 patients were included in the study. Twenty-one patients (95%) suffered from severe ARDS and 14 patients (64%) survived to ICU discharge. On admission, the majority of patients had low Se status biomarkers and Zn levels, along with elevated inflammatory parameters. Se supplementation significantly elevated Se (p = 0.027) and selenoprotein P levels (SELENOP; p = 0.016) to normal range. Accordingly, glutathione peroxidase 3 (GPx3) activity increased over time (p = 0.021). Se biomarkers, most notably SELENOP, were inversely correlated with CRP (rs = -0.495), PCT (rs = -0.413), IL-6 (rs = -0.429), IL-1ß (rs = -0.440) and IL-10 (rs = -0.461). Positive associations were found for CD8+ T cells (rs = 0.636), NK cells (rs = 0.772), total IgG (rs = 0.493) and PaO2/FiO2 ratios (rs = 0.504). In addition, survivors tended to have higher Se levels after 10 to 14 days compared to non-survivors (p = 0.075). Sufficient Se and Zn levels may potentially be of clinical significance for an adequate immune response in critically ill patients with severe COVID-19 ARDS.

Effects of Bacillus firmus e volumine ex muris cellulae 6x on cytolytic activity of natural killer cells in vitro

Natural killer (NK) cells are among the first in defense of the innate immune system by eliminating a variety of abnormal or stressed cells such as cancer cells or virus-infected cells. Individuals who exhibit low cytolytic NK cell activity are believed to be at higher risk of viral infection, tumorigenesis, and various other diseases of the immune system. Therefore, restoration of impaired NK cell function might be an essential step in immunostimulatory therapy of immunocompromised patients. Bacillus firmus is a non-pathogenic gram-positive bacterium of the environment, which possesses various immunomodulatory properties in vitro and in vivo. This retrospective study reports on the effect of B. firmus on the activity of NK cells in vitro. Basal cytolytic NK cell activity against tumor cells among peripheral blood mononuclear cells (PBMCs) of routine patients was determined in a standardized NK cell cytotoxicity assay. The impact of cultivation of PBMCs with B. firmus preparation Bacillus firmus e volumine ex muris cellulae (Bacillus firmus (evc)) 6x on tumor cell killing by NK cells was monitored in relation to basal NK cell activity. This study showed that stimulation of PBMCs with Bacillus firmus (evc) 6x in vitro led to a significant increase in NK cell function. Substantial improvement in cytolytic NK cell activity (more than 1.3-fold of basal activity) was much more pronounced for patients with compromised NK cell function. Due to its immunostimulatory mode of action, Bacillus firmus (evc) may be of particular importance in therapy of patients with NK cell deficiency.

Allergen-induced IgE-dependent gut inflammation in a human PBMC-engrafted murine model of allergy.

BACKGROUND: Humanized murine models comprise a new tool to analyze novel therapeutic strategies for allergic diseases of the intestine. OBJECTIVE: In this study we developed a human PBMC-engrafted murine model of allergen-driven gut inflammation and analyzed the underlying immunologic mechanisms. METHODS: Nonobese diabetic (NOD)-scid-γc(-/-) mice were injected intraperitoneally with human PBMCs from allergic donors together with the respective allergen or not. Three weeks later, mice were challenged with the allergen orally or rectally, and gut inflammation was monitored with a high-resolution video miniendoscopic system, as well as histologically. RESULTS: Using the aeroallergens birch or grass pollen as model allergens and, for some donors, also hazelnut allergen, we show that allergen-specific human IgE in murine sera and allergen-specific proliferation and cytokine production of human CD4(+) T cells recovered from spleens after 3 weeks could only be measured in mice treated with PBMCs plus allergen. Importantly, these mice had the highest endoscopic scores evaluating translucent structure, granularity, fibrin, vascularity, and stool after oral or rectal allergen challenge and a strong histologic inflammation of the colon. Analyzing the underlying mechanisms, we demonstrate that allergen-associated colitis was dependent on IgE, human IgE receptor-expressing effector cells, and the mediators histamine and platelet-activating factor. CONCLUSION: These results demonstrate that allergic gut inflammation can be induced in human PBMC-engrafted mice, allowing the investigation of pathophysiologic mechanisms of allergic diseases of the intestine and evaluation of therapeutic interventions.