Serum IL-23, IL-10, and TNF-α predict in-hospital mortality in COVID-19 patients.

Objective: The hyperinflammatory response, caused by severe acute respiratory syndrome-2 (SARS-CoV-2), is the most common cause of death in patients with coronavirus disease 2019 (COVID-19). The etiopathogenesis of this illness is not fully understood. Macrophages appear to play a key part in COVID-19's pathogenic effects. Therefore, this study aims to examine serum inflammatory cytokines associated with the activation state of macrophages in COVID-19 patients and attempt to find accurate predictive markers for disease severity and mortality risk in hospital. Methods: 180 patients with COVID-19 and 90 healthy controls (HCs) participated in this study. Patients were divided into three different subgroups, mild (n=81), severe (n=60), and critical groups (n=39). Serum samples were collected and IL (Interleukin)-10, IL-23, tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), IL-17, monocyte chemoattractant protein-1 (MCP-1) and chemokine ligand 3 (CCL3) were determined by ELISA. In parallel, myeloperoxidase (MPO) and C-reactive protein (CRP) were measured using colorimetric and electrochemiluminescence methods, respectively. Data were collected, and their associations with disease progression and mortality were assessed using regression models and receiver operating characteristic (ROC) curves. Results: Compared to HCs, a significant increase in IL-23, IL-10, TNF-α, IFN-γ and MCP-1, were observed in COVID-19 patients. Serum levels of IL-23, IL-10, and TNF-α were significantly higher in COVID-19 patients with critical cases compared to mild and severe cases, and correlated positively with CRP level. However, non-significant changes were found in serum MPO and CCL3 among the studied groups. Moreover, significant positive association has been observed among increased IL-10, IL-23 and TNF-α in serum of COVID-19 patients. Furthermore, a binary logistic regression model was applied to predict death's independent factors. Results showed that IL-10 alone or in combination with IL23 and TNF-α are strongly linked with non-survivors in COVID-19 patients. Finally, ROC curve results uncovered that IL-10, IL-23 and TNF-α were excellent predictors for prognosing COVID-19. Conclusion: The elevations of IL-10, IL-23, and TNF-α levels were seen in severe and critical cases of COVID-19 patients and their elevations were linked to the in-hospital mortality of the disease. A prediction model shows that the determination of these cytokines upon admission is important and should be done on COVID-19 patients as a way of evaluating the prognosis of the disease. COVID-19 Patients with high IL-10, IL-23, and TNF-α on admission are more likely to experience a severe form of the disease; therefore, those patients should be cautionary monitored and treated.

COVID-19 vaccination exacerbates ex vivo IL-6 release from isolated PBMCs.

Ex vivo culturing of isolated PBMCs from individuals vaccinated with the coronavirus disease 2019 (COVID-19) vaccine BNT162b1 revealed a pronounced T cell response in the presence of the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. The latter was 10-fold more pronounced than the ex vivo response of PBMCs from the same individuals to other common pathogen T cell epitope pools, suggesting COVID-19 vaccination to induce RBD-specific T cell responses and not to facilitate T cell (re)activity in general. In the current study we investigated whether COVID-19 vaccination long-lastingly affects plasma interleukin (IL)-6 concentrations, complete blood counts, ex vivo IL-6 and IL-10 secretion of PBMCs cultured under basal conditions or in the presence of concanavalin (Con) A and lipopolysaccharide (LPS), salivary cortisol and α-amylase, mean arterial pressure (MAP), heart rate (HR) as well as mental and physical health status. The study was initially designed to investigate whether the presence vs. absence of own pets during urban upbringing has protective effects against psychosocial stress-induced immune activation during adulthood. However, as COVID-19 vaccines were approved while the study was ongoing and as, therefore, both vaccinated and non-vaccinated individuals have been recruited, we were able to stratify our data set with respect to the COVID-19 vaccination status and to assess the long-lasting effects of COVID-19 vaccination on physiological immunological, cardiovascular and psychosomatic health parameters. This data is presented in the current study. We show that isolated PBMCs from individuals vaccinated against COVID-19 show a ~ 600-fold increase in basal and a ~ 6000-fold increase in ConA-induced proinflammatory IL-6 secretion, and a ~ 2-fold increase in basal and ConA-induced antiinflammatory IL-10 secretion, both in comparison with non-vaccinated individuals. In contrast, LPS-induced ex vivo IL-6 and IL-10 secretions were not affected by vaccination status, as were plasma IL-6 concentrations, complete blood counts, salivary cortisol and α-amylase, cardiovascular measures and psychosomatic health. In summary, our findings are of relevance for many clinical studies ran before/during the pandemic, clearly indicating that consideration of participants' vaccination status is critical, at least when assessing ex vivo PBMC functionality.

The Effect of Weekly 50,000 IU Vitamin D3 Supplements on the Serum Levels of Selected Cytokines Involved in Cytokine Storm: A Randomized Clinical Trial in Adults with Vitamin D Deficiency.

This research aimed to evaluate the effects of high-dose cholecalciferol (VD3) supplements (50,000 IU/week) on selected circulating cytokines associated with cytokine storms in adults with vitamin D deficiency. This clinical trial, based in Jordan, included 50 participants receiving vitamin D3 supplements (50,000 IU/week) for 8 weeks; the exact number was assigned to the control group. Interleukin-6 (IL-6), interleukin-1ß (IL-1ß), interleukin-10 (IL-10), tumor necrotic factor-α (TNF-α), and leptin were measured in serum at baseline and 10 weeks (wash out: 2 weeks). Our results revealed that vitamin D3 supplementation significantly increased the serum levels of 25OHD, IL-6, IL-10, IL-1ß, and leptin compared with baseline. In contrast, the serum level of TNF-α insignificantly increased in the group receiving vitamin D3 supplementation. Although the observations of this trial may refer to a potential negative effect of VD3 supplementation during cytokine storms, further trials are required to clarify the potential benefits of VD3 supplement during cytokine storms.

Adaptive immunity to SARS-CoV-2 infection: A systematic review.

Background: There is evidence that the adaptive or acquired immune system is one of the crucial variables in differentiating the course of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This work aimed to analyze the immunopathological aspects of adaptive immunity that are involved in the progression of this disease. Methods: This is a systematic review based on articles that included experimental evidence from in vitro assays, cohort studies, reviews, cross-sectional and case-control studies from PubMed, SciELO, MEDLINE, and Lilacs databases in English, Portuguese, or Spanish between January 2020 and July 2022. Results: Fifty-six articles were finalized for this review. CD4+ T cells were the most resolutive in the health-disease process compared with B cells and CD8+ T lymphocytes. The predominant subpopulations of T helper lymphocytes (Th) in critically ill patients are Th1, Th2, Th17 (without their main characteristics) and regulatory T cells (Treg), while in mild cases there is an influx of Th1, Th2, Th17 and follicular T helper cells (Tfh). These cells are responsible for the secretion of cytokines, including interleukin (IL) - 6, IL-4, IL-10, IL-7, IL-22, IL-21, IL-15, IL-1α, IL-23, IL-5, IL-13, IL-2, IL-17, tumor necrosis factor alpha (TNF-α), CXC motivating ligand (CXCL) 8, CXCL9 and tumor growth factor beta (TGF-ß), with the abovementioned first 8 inflammatory mediators related to clinical benefits, while the others to a poor prognosis. Some CD8+ T lymphocyte markers are associated with the severity of the disease, such as human leukocyte antigen (HLA-DR) and programmed cell death protein 1 (PD-1). Among the antibodies produced by SARS-CoV-2, Immunoglobulin (Ig) A stood out due to its potent release associated with a more severe clinical form. Conclusions: It is concluded that through this study it is possible to have a brief overview of the main immunological biomarkers and their function during SARS-CoV-2 infection in particular cell types. In critically ill individuals, adaptive immunity is varied, aberrantly compromised, and late. In particular, the T-cell response is also an essential and necessary component in immunological memory and therefore should be addressed in vaccine formulation strategies.

Prognostic peripheral blood biomarkers at ICU admission predict COVID-19 clinical outcomes.

The COVID-19 pandemic continues to challenge the capacities of hospital ICUs which currently lack the ability to identify prospectively those patients who may require extended management. In this study of 90 ICU COVID-19 patients, we evaluated serum levels of four cytokines (IL-1ß, IL-6, IL-10 and TNFα) as well as standard clinical and laboratory measurements. On 42 of these patients (binned into Initial and Replication Cohorts), we further performed CyTOF-based deep immunophenotyping of peripheral blood mononuclear cells with a panel of 38 antibodies. All measurements and patient samples were taken at time of ICU admission and retrospectively linked to patient clinical outcomes through statistical approaches. These analyses resulted in the definition of a new measure of patient clinical outcome: patients who will recover after short ICU stays (< 6 days) and those who will subsequently die or recover after long ICU stays (≥6 days). Based on these clinical outcome categories, we identified blood prognostic biomarkers that, at time of ICU admission, prospectively distinguish, with 91% sensitivity and 91% specificity (positive likelihood ratio 10.1), patients in the two clinical outcome groups. This is achieved through a tiered evaluation of serum IL-10 and targeted immunophenotyping of monocyte subsets, specifically, CD11clow classical monocytes. Both immune biomarkers were consistently elevated ( ≥15 pg/ml and ≥2.7 x107/L for serum IL-10 and CD11clow classical monocytes, respectively) in those patients who will subsequently die or recover after long ICU stays. This highly sensitive and specific prognostic test could prove useful in guiding clinical resource allocation.

Inflammatory profile of convalescent plasma to treat COVID: Impact of amotosalen/UVA pathogen reduction technology.

Blood products in therapeutic transfusion are now commonly acknowledged to contain biologically active constituents during the processes of preparation. In the midst of a worldwide COVID-19 pandemic, preliminary evidence suggests that convalescent plasma may lessen the severity of COVID-19 if administered early in the disease, particularly in patients with profound B-cell lymphopenia and prolonged COVID-19 symptoms. This study examined the influence of photochemical Pathogen Reduction Treatment (PRT) using amotosalen-HCl and UVA light in comparison with untreated control convalescent plasma (n= 72 - paired samples) - cFFP, regarding soluble inflammatory factors: sCD40L, IFN-alpha, IFN-beta, IFN-gamma, IL-1 beta, IL-6, IL-8, IL-10, IL-18, TNF-alpha and ex-vivo inflammatory bioactivity on endothelial cells. We didn't observe significant modulation of the majority of inflammatory soluble factors (8 of 10 molecules tested) pre- or post-PRT. We noted that IL-8 concentrations were significantly decreased in cFFP with PRT, whereas the IL-18 concentration was increased by PRT. In contrast, endothelial cell release of IL-6 was similar whether cFFP was pre-treated with or without PRT. Expression of CD54 and CD31 in the presence of cFFP were similar to control levels, and both were significant decreased in when cFFP had been pre-treated by PRT. It will be interesting to continue investigations of IL-18 and IL-8, and the physiopathological effect of PRT- treated convalescent plasma and in clinical trials. But overall, it appears that cFFP post-PRT were not excessively pro-inflammatory. Further research, including a careful clinical evaluation of CCP-treated patients, will be required to thoroughly define the clinical relevance of these findings.

The shed P2X7 receptor is an index of adverse clinical outcome in COVID-19 patients.

Introduction: The pathophysiology of the Corona Virus Disease 2019 (COVID-19) is incompletely known. A robust inflammatory response caused by viral replication is a main cause of the acute lung and multiorgan injury observed in critical patients. Inflammasomes are likely players in COVID-19 pathogenesis. The P2X7 receptor (P2X7R), a plasma membrane ATP-gated ion channel, is a main activator of the NLRP3 inflammasome, of the ensuing release of inflammatory cytokines and of cell death by pyroptosis. The P2X7R has been implicated in COVID-19-dependent hyperinflammation and in the associated multiorgan damage. Shed P2X7R (sP2X7R) and shed NLRP3 (sNLRP3) have been detected in plasma and other body fluids, especially during infection and inflammation. Methods: Blood samples from 96 patients with confirmed SARS-CoV-2 infection with various degrees of disease severity were tested at the time of diagnosis at hospital admission. Standard haematological parameters and IL-6, IL-10, IL-1ß, sP2X7R and sNLRP3 levels were measured, compared to reference values, statistically validated, and correlated to clinical outcome. Results: Most COVID-19 patients included in this study had lymphopenia, eosinopenia, neutrophilia, increased inflammatory and coagulation indexes, and augmented sNLRP3, IL-6 and IL-10 levels. Blood concentration of sP2X7R was also increased, and significantly positively correlated with lymphopenia, procalcitonin (PCT), IL-10, and alanine transaminase (ALT). Patients with increased sP2X7R levels at diagnosis also showed fever and respiratory symptoms, were more often transferred to Pneumology division, required mechanical ventilation, and had a higher likelihood to die during hospitalization. Conclusion: Blood sP2X7R was elevated in the early phases of COVID-19 and predicted an adverse clinical outcome. It is suggested that sP2X7R might be a useful marker of disease progression.

Autophagy Receptor p62 Regulates SARS-CoV-2-Induced Inflammation in COVID-19.

As autophagy can promote or inhibit inflammation, we examined autophagy-inflammation interplay in COVID-19. Autophagy markers in the blood of 19 control subjects and 26 COVID-19 patients at hospital admission and one week later were measured by ELISA, while cytokine levels were examined by flow cytometric bead immunoassay. The antiviral IFN-α and proinflammatory TNF, IL-6, IL-8, IL-17, IL-33, and IFN-γ were elevated in COVID-19 patients at both time points, while IL-10 and IL-1ß were increased at admission and one week later, respectively. Autophagy markers LC3 and ATG5 were unaltered in COVID-19. In contrast, the concentration of autophagic cargo receptor p62 was significantly lower and positively correlated with TNF, IL-10, IL-17, and IL-33 at hospital admission, returning to normal levels after one week. The expression of SARS-CoV-2 proteins NSP5 or ORF3a in THP-1 monocytes caused an autophagy-independent decrease or autophagy-inhibition-dependent increase, respectively, of intracellular/secreted p62, as confirmed by immunoblot/ELISA. This was associated with an NSP5-mediated decrease in TNF/IL-10 mRNA and an ORF3a-mediated increase in TNF/IL-1ß/IL-6/IL-10/IL-33 mRNA levels. A genetic knockdown of p62 mimicked the immunosuppressive effect of NSP5, and a p62 increase in autophagy-deficient cells mirrored the immunostimulatory action of ORF3a. In conclusion, the proinflammatory autophagy receptor p62 is reduced inacute COVID-19, and the balance between autophagy-independent decrease and autophagy blockade-dependent increase of p62 levels could affect SARS-CoV-induced inflammation.

The specialized pro-resolving lipid mediator Protectin D1 affects macrophages differentiation and activity in Adult-onset Still's disease and COVID-19, two hyperinflammatory diseases sharing similar transcriptomic profiles.

Introduction: COVID-19 and autoinflammatory diseases, such as Adult-onset Still's Disease (AOSD), are characterized by hyperinflammation, in which it is observed massive production and uncontrolled secretion of pro-inflammatory cytokines. The specialized pro-resolving lipid mediators (SPMs) family is one the most important processes counteracting hyperinflammation inducing tissue repair and homeostasis restoration. Among SPMs, Protectin D1 (PD1) is able to exert antiviral features, at least in animal models. The aim of this study was to compare the transcriptome of peripheral blood mononuclear cells (PBMCs) from patients with AOSD and COVID-19 and to evaluate the role of PD1 on those diseases, especially in modulating macrophages polarization. Methods: This study enrolled patients with AOSD, COVID-19, and healthy donors HDs, undergoing clinical assessment and blood sample collection. Next-generation deep sequencing was performed to identify differences in PBMCs transcripts profiles. Plasma levels of PD1 were assessed by commercial ELISA kits. Monocyte-derived macrophages were polarized into M1 and M2 phenotypes. We analyzed the effect of PD1 on macrophages differentiation. At 10 days, macrophages were analyzed for surface expression of subtypes markers by flow cytometry. Cytokines production was measured in supernatants by Bio-Plex Assays. Results: In the transcriptomes from AOSD patients and COVID-19 patients, genes involved in inflammation, lipid catabolism, and monocytes activation were specifically dysregulated in AOSD and COVID-19 patients when compared to HDs. Patients affected by COVID-19, hospitalized in intensive care unit (ICU), showed higher levels of PD1 when compared to not-ICU hospitalized patients and HDs (ICU COVID-19 vs not-ICU COVID-19, p= 0.02; HDs vs ICU COVID-19, p= 0.0006). PD1 levels were increased in AOSD patients with SS ≥1 compared to patients with SS=0 (p=0.028) and HDs (p=0.048). In vitro treatment with PD1 of monocytes-derived macrophages from AOSD and COVID-19 patients induced a significant increase of M2 polarization vs control (p<0.05). Furthermore, a significant release of IL-10 and MIP-1ß from M2 macrophages was observed when compared to controls (p<0.05). Discussion: PD1 is able to induce pro-resolutory programs in both AOSD and COVID-19 increasing M2 polarization and inducing their activity. In particular, PD1-treated M2 macrophages from AOSD and COVID-19 patients increased the production of IL-10 and enhanced homeostatic restoration through MIP-1ß production.

Mucosal immunization with lactiplantibacillus plantarum-displaying recombinant SARS-CoV-2 epitopes on the surface induces humoral and mucosal immune responses in mice.

BACKGROUND: The use of probiotic lactic acid bacteria as a mucosal vaccine vector is considered a promising alternative compared to the use of other microorganisms because of its "Generally Regarded as Safe" status, its potential adjuvant properties, and its tolerogenicity to the host. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), is highly transmissible and pathogenic. This study aimed to determine the potential of Lactiplantibacillus plantarum expressing SARS-CoV-2 epitopes as a mucosal vaccine against SARS-CoV-2. RESULTS: In this study, the possible antigenic determinants of the spike (S1-1, S1-2, S1-3, and S1-4), membrane (ME1 and ME2), and envelope (E) proteins of SARS-CoV-2 were predicted, and recombinant L. plantarum strains surface-displaying these epitopes were constructed. Subsequently, the immune responses induced by these recombinant strains were compared in vitro and in vivo. Most surface-displayed epitopes induced pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α and interleukin (IL)-6] and anti-inflammatory cytokines (IL-10) in lipopolysaccharide-induced RAW 264.7, with the highest anti-inflammatory to pro-inflammatory cytokine ratio in the S1-1 and S1-2 groups, followed by that in the S1-3 group. When orally administered of recombinant L. plantarum expressing SARS-CoV-2 epitopes in mice, all epitopes most increased the expression of IL-4, along with induced levels of TNF-α, interferon-gamma, and IL-10, specifically in spike protein groups. Thus, the surface expression of epitopes from the spike S1 protein in L. plantarum showed potential immunoregulatory effects, suggesting its ability to potentially circumvent hyperinflammatory states relevant to monocyte/macrophage cell activation. At 35 days post immunization (dpi), serum IgG levels showed a marked increase in the S1-1, S1-2, and S1-3 groups. Fecal IgA levels increased significantly from 21 dpi in all the antigen groups, but the boosting effect after 35 dpi was explicitly observed in the S1-1, S1-2, and S1-3 groups. Thus, the oral administration of SARS-CoV-2 antigens into mice induced significant humoral and mucosal immune responses. CONCLUSION: This study suggests that L. plantarum is a potential vector that can effectively deliver SARS-CoV-2 epitopes to intestinal mucosal sites and could serve as a novel approach for SARS-CoV-2 mucosal vaccine development.

Evaluation of the immunomodulatory effects of interleukin-10 on peripheral blood immune cells of COVID-19 patients: Implication for COVID-19 therapy.

Objective: Several therapies with immune-modulatory functions have been proposed to reduce the overwhelmed inflammation associated with COVID-19. Here we investigated the impact of IL-10 in COVID-19, through the ex-vivo assessment of the effects of exogenous IL-10 on SARS-CoV-2-specific-response using a whole-blood platform. Methods: Two cohorts were evaluated: in "study population A", plasma levels of 27 immune factors were measured by a multiplex (Luminex) assay in 39 hospitalized "COVID-19 patients" and 29 "NO COVID-19 controls" all unvaccinated. In "study population B", 29 COVID-19 patients and 30 NO COVID-19-Vaccinated Controls (NO COVID-19-VCs) were prospectively enrolled for the IL-10 study. Whole-blood was stimulated overnight with SARS-COV-2 antigens and then treated with IL-10. Plasma was collected and used for ELISA and multiplex assay. In parallel, whole-blood was stimulated and used for flow cytometry analysis. Results: Baseline levels of several immune factors, including IL-10, were significantly elevated in COVID-19 patients compared with NO COVID-19 subjects in "study population A". Among them, IL-2, FGF, IFN-γ, and MCP-1 reached their highest levels within the second week of infection and then decreased. To note that, MCP-1 levels remained significantly elevated compared with controls. IL-10, GM-CSF, and IL-6 increased later and showed an increasing trend over time. Moreover, exogenous addition of IL-10 significantly downregulated IFN-γ response and several other immune factors in both COVID-19 patients and NO COVID-19-VCs evaluated by ELISA and a multiplex analysis (Luminex) in "study population B". Importantly, IL-10 did not affect cell survival, but decreased the frequencies of T-cells producing IFN-γ, TNF-α, and IL-2 (p<0.05) and down-modulated HLA-DR expression on CD8+ and NK cells. Conclusion: This study provides important insights into immune modulating effects of IL-10 in COVID-19 and may provide valuable information regarding the further in vivo investigations.

Phosphate and IL-10 concentration as predictors of long-covid in hemodialysis patients: A Brazilian study.

Background: The global burden of persistent COVID-19 in hemodialysis (HD) patients is a worrisome scenario worth of investigation for the critical care of chronic kidney disease (CKD). We performed an exploratory post-hoc study from the trial U1111-1237-8231 with two specific aims: i) to investigate the prevalence of COVID-19 infection and long COVID symptoms from our Cohort of 178 Brazilians HD patients. ii) to identify whether baseline characteristics should predict long COVID in this sample. Methods: 247 community-dwelling older (>60 years) patients (Men and women) undergoing HD (glomerular filtration rate < 15 mL/min/1.73m2) with arteriovenous fistula volunteered for this study. All patients presented hypertension and diabetes. Patients were divided in two groups: without long-COVID and with long-COVID. Body composition, handgrip strength, functional performance, iron metabolism, phosphate, and inflammatory profile were assessed. Patients were screened for 11-months after COVID-19 infection. Results were considered significant at P < 0.05. Results: We found that more than 85% of the COVID-19 infected patients presented a severe condition during the infection. In our sample, the mortality rate over 11-month follow was relatively low (8.4%) when compared to worldwide (approximately 36%). Long COVID was highly prevalent in COVID-19 survivors representing more than 80% of all cases. Phosphate and IL-10 were higher in the long COVID group, but only phosphate higher than 5.35 mg/dL appears to present an increased prevalence of long COVID, dyspnea, and fatigue. Conclusion: There was a high prevalence of COVID-19 infection and long COVID in HD patients from the Brazilian trial 'U1111-1237-8231'. HD clinics should be aware with phosphate range in HD patients as a possible target for adverse post-COVID events.

Excessive IL-10 and IL-18 trigger hemophagocytic lymphohistiocytosis-like hyperinflammation and enhanced myelopoiesis.

BACKGROUND: Hyperinflammation is a life-threatening condition associated with various clinical disorders characterized by excessive immune activation and tissue damage. Multiple cytokines promote the development of hyperinflammation; however, the contribution of IL-10 remains unclear despite emerging speculations for a pathological role. Clinical observations from hemophagocytic lymphohistiocytosis (HLH), a prototypical hyperinflammatory disease, suggest that IL-18 and IL-10 may collectively promote the onset of a hyperinflammatory state. OBJECTIVE: We aimed to investigate the collaborative roles of IL-10 and IL-18 in hyperinflammation. METHODS: A comprehensive plasma cytokine profile for 87 secondary HLH patients was first depicted and analyzed. We then investigated the systemic and cellular effects of coelevated IL-10 and IL-18 in a transgenic mouse model and cultured macrophages. Single-cell RNA sequencing was performed on the monocytes/macrophages isolated from secondary HLH patients to explore the clinical relevance of IL-10/IL-18-mediated cellular signatures. The therapeutic efficacy of IL-10 blockade was tested in HLH mouse models. RESULTS: Excessive circulating IL-10 and IL-18 triggered a lethal hyperinflammatory disease recapitulating HLH-like phenotypes in mice, driving peripheral lymphopenia and a striking shift toward enhanced myelopoiesis in the bone marrow. IL-10 and IL-18 polarized cultured macrophages to a distinct proinflammatory state with pronounced expression of myeloid cell-recruiting chemokines. Transcriptional characterization suggested the IL-10/IL-18-mediated cellular features were clinically relevant with HLH, showing enhanced granzyme expression and proteasome activation in macrophages. IL-10 blockade protected against the lethal disease in HLH mouse models. CONCLUSION: Coelevated IL-10 and IL-18 are sufficient to drive HLH-like hyperinflammatory syndrome, and blocking IL-10 is protective in HLH models.

[Analyze the clinical characteristics of mild and severe SARS-CoV-2 infected patients based on the local Omicron variant epidemic].

OBJECTIVE: To analyze the epidemic characteristics and clinical key indicators of the patients infected with SARS-CoV-2 of the local Omicron variant epidemic, to understand the clinical characteristics of mild and severe patients, and to provide a scientific basis for the effective treatment and prevention of severe disease. METHODS: From January 2020 to March 2022, the clinical and laboratory data of COVID-19 patients admitted to the Fifth People's Hospital of Wuxi were retrospective analyzed, including virus gene subtypes, demographic information, clinical classification, main clinical symptoms, and key indicators of clinical testing, and the changes of clinical characteristics of the patients infected with SARS-CoV-2. RESULTS: A total of 150 patients with SARS-CoV-2 infection were admitted, 78, 52 and 20 in 2020, 2021 and 2022, including 10, 1 and 1 severe patient, and the main infected virus strains were L, Delta, and Omicron variants. The relapse rate of patients infected with the Omicron variant was as high as 15.0% (3/20), the incidence of diarrhea decreased to 10.0% (2/20), the incidence of severe disease decreased to 5.0% (1/20), and the number of hospitalization days of mild patients increased compared with 2020 (days: 20.43±1.78 vs. 15.84±1.12); respiratory symptoms were reduced, and the proportion of pulmonary lesions decreased to 10.5%; the virus titer of severely ill patients with SARS-CoV-2 Omicron variant infection (day 3) was higher than that of L-type strain (Ct value: 23.92±1.16 vs. 28.19±1.54). The acute plasma cytokines interleukin (IL-6, IL-10) and tumor necrosis factor-α (TNF-α) were significantly lower in patients with severe Omicron variant new coronavirus infection than those with mild disease [IL-6 (ng/L): 3.92±0.24 vs. 6.02±0.41, IL-10 (ng/L): 0.58±0.01 vs. 4.43±0.32, TNF-α (ng/L): 1.73±0.02 vs. 6.91±1.25, all P < 0.05], while γ-interferon (IFN-γ) and IL-17A were significantly higher than patients with mild disease [IFN-γ (ng/L): 23.07±0.17 vs. 13.52±2.34, IL-17A (ng/L): 35.58±0.08 vs. 26.39±1.37, both P < 0.05]. Compared with previous epidemics (2020 and 2021), the proportion of CD4/CD8 ratio, lymphocyte count, eosinophil and serum creatinine decreased in patients with mild Omicron infection in 2022 (36.8% vs. 22.1%, 9.8%; 36.8% vs. 23.5%, 7.8%; 42.1% vs. 41.2%, 15.7%; 42.1% vs. 19.1%, 9.8%), the proportion of patients with elevated monocyte count and procalcitonin was large (42.1% vs. 50.0%, 23.5%; 21.1% vs. 5.9%, 0). CONCLUSIONS: The incidences of severe disease in patients with SARS-CoV-2 Omicron variant infection was significantly lower than that of previous epidemics, and the occurrence of severe diseases was still related to the underlying diseases.

Inflammatory Response and Activation of Coagulation after COVID-19 Infection.

SARS-CoV-2 (COVID-19) infection is responsible for causing a disease with a wide spectrum of clinical presentations. Predisposition to thromboembolic disease due to excessive inflammation is also attributed to the disease. The objective of this study was to characterize the clinical and laboratory aspects of hospitalized patients, in addition to studying the pattern of serum cytokines, and associate them with the occurrence of thromboembolic events. METHODOLOGY: A retrospective cohort study with 97 COVID-19 patients hospitalized from April to August 2020 in the Triângulo Mineiro macro-region was carried out. A review of medical records was conducted to evaluate the clinical and laboratory aspects and the frequency of thrombosis, as well as the measurement of cytokines, in the groups that presented or did not present a thrombotic event. RESULTS: There were seven confirmed cases of thrombotic occurrence in the cohort. A reduction in the time of prothrombin activity was observed in the group with thrombosis. Further, 27.8% of all patients had thrombocytopenia. In the group that had thrombotic events, the levels of IL1b, IL-10, and IL2 were higher (p < 0.05). CONCLUSIONS: In the studied sample, there was an increase in the inflammatory response in patients with thrombotic events, confirmed by the increase in cytokines. Furthermore, in this cohort, a link was observed between the IL-10 percentage and an increased chance of a thrombotic event.

Correlation of Plasma 25(OH)D3 and Vitamin D Binding Protein Levels with COVID-19 Severity and Outcome in Hospitalized Patients.

BACKGROUND: The Coronavirus Disease-19 (COVID-19) caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) has been declared a worldwide pandemic. The severity of COVID-19 varies greatly across infected individuals. Possible factors may include plasma levels of 25(OH)D and vitamin D binding protein (DBP), as both are involved in the host immune response. Other possible nutrition-related factors include malnutrition and/or obesity which disrupt the optimal host immune response to infections. Current literature shows inconsistent evidence about the association of plasma 25(OH)D3 and DBP on infection severity and clinical outcomes. OBJECTIVES: This study aimed to measure plasma 25(OH)D3 and DBP in hospitalized COVID-19 cases and assess their correlation with infection severity, inflammatory markers, and clinical outcome. METHODS: 167 patients were included in this analytical cross-sectional study, of which 81 were critical and 86 were non-critical hospitalized COVID-19 patients. Plasma levels of 25(OH)D3, DBP, and the inflammatory cytokines, IL-6, IL-8, IL-10, and TNF-α were assessed using the Enzyme-linked Immunosorbent Assay (ELISA). Information regarding biochemical and anthropometrical indices, hospital length of stay (LoS), and illness outcome was obtained from the medical records. RESULTS: Plasma 25(OH)D3 level was found to be significantly lower in critical compared to non-critical patients (Median = 8.38 (IQR = 2.33) vs. 9.83 (IQR = 3.03) nmol/L, respectively; p < 0.001), and it positively correlated with hospital LoS. However, plasma 25(OH)D3 did not correlate with mortality or any of the inflammatory markers. DBP on the other hand correlated positively with mortality (rs = 0.188, p = 0.015) and hospital LoS (rs = 0.233, p = 0.002). DBP was significantly higher in critical than non-critical patients (Median = 1262.18 (IQR = 463.66) vs. 1153.35 (IQR = 418.46) ng/mL, respectively; p < 0.001). Furthermore, IL-6 and IL-8 were significantly higher in critical than non-critical patients. However, no differences were found in IL-10, TNF-α, IL-10/TNF-α, TNF-α/IL-10, IL-6/IL-10, or CRP between groups. CONCLUSION: The current study found that critical COVID-19 patients had lower 25(OH)D3 than non-critical patients, yet, levels were found to be suboptimal in both groups. Further, critical patients had higher DBP levels as compared to non-critical patients. This finding may encourage future research to unravel the effects of this understudied protein that appears to have significant associations with inflammation, even though the precise mechanism is unknown.

Characterisation of the pro-inflammatory cytokine signature in severe COVID-19.

Clinical outcomes from infection with SARS-CoV-2, the cause of the COVID-19 pandemic, are remarkably variable ranging from asymptomatic infection to severe pneumonia and death. One of the key drivers of this variability is differing trajectories in the immune response to SARS-CoV-2 infection. Many studies have noted markedly elevated cytokine levels in severe COVID-19, although results vary by cohort, cytokine studied and sensitivity of assay used. We assessed the immune response in acute COVID-19 by measuring 20 inflammatory markers in 118 unvaccinated patients with acute COVID-19 (median age: 70, IQR: 58-79 years; 48.3% female) recruited during the first year of the pandemic and 44 SARS-CoV-2 naïve healthy controls. Acute COVID-19 was associated with marked elevations in nearly all pro-inflammatory markers, whilst eleven markers (namely IL-1ß, IL-2, IL-6, IL-10, IL-18, IL-23, IL-33, TNF-α, IP-10, G-CSF and YKL-40) were associated with disease severity. We observed significant correlations between nearly all markers elevated in those infected with SARS-CoV-2 consistent with widespread immune dysregulation. Principal component analysis highlighted a pro-inflammatory cytokine signature (with strongest contributions from IL-1ß, IL-2, IL-6, IL-10, IL-33, G-CSF, TNF-α and IP-10) which was independently associated with severe COVID-19 (aOR: 1.40, 1.11-1.76, p=0.005), invasive mechanical ventilation (aOR: 1.61, 1.19-2.20, p=0.001) and mortality (aOR 1.57, 1.06-2.32, p = 0.02). Our findings demonstrate elevated cytokines and widespread immune dysregulation in severe COVID-19, adding further evidence for the role of a pro-inflammatory cytokine signature in severe and critical COVID-19.

IL-10 Promotes CXCL13 Expression in Macrophages Following Foot-and-Mouth Disease Virus Infection.

Foot-and-mouth disease (FMD) is one of the most contagious livestock diseases in the world, posing a constant global threat to the animal trade and national economies. The chemokine C-X-C motif chemokine ligand 13 (CXCL13), a biomarker for predicting disease progression in some diseases, was recently found to be increased in sera from mice infected with FMD virus (FMDV) and to be associated with the progression and severity of the disease. However, it has not yet been determined which cells are involved in producing CXCL13 and the signaling pathways controlling CXCL13 expression in these cells. In this study, the expression of CXCL13 was found in macrophages and T cells from mice infected with FMDV, and CXCL13 was produced in bone-marrow-derived macrophages (BMDMs) by activating the nuclear factor-kappaB (NF-κB) and JAK/STAT pathways following FMDV infection. Interestingly, CXCL13 concentration was decreased in sera from interleukin-10 knock out (IL-10-/-) mice or mice blocked IL-10/IL-10R signaling in vivo after FMDV infection. Furthermore, CXCL13 was also decreased in IL-10-/- BMDMs and BMDMs treated with anti-IL-10R antibody following FMDV infection in vitro. Lastly, it was demonstrated that IL-10 regulated CXCL13 expression via JAK/STAT rather than the NF-κB pathway. In conclusion, the study demonstrated for the first time that macrophages and T cells were the cellular sources of CXCL13 in mice infected with FMDV; CXCL13 was produced in BMDMs via NF-κB and JAK/STAT pathways; and IL-10 promoted CXCL13 expression in BMDMs via the JAK/STAT pathway.

Effect of Cytomegalovirus Reactivation on Inflammatory Status and Mortality of Older COVID-19 Patients.

Herpesviridae reactivation such as cytomegalovirus (CMV) has been described in severe COVID-19 (COronaVIrusDisease-2019). This study aimed to understand if CMV reactivation in older COVID-19 patients is associated with increased inflammation and in-hospital mortality. In an observational single-center cohort study, 156 geriatric COVID-19 patients were screened for CMV reactivation by RT-PCR. Participants underwent a comprehensive clinical investigation that included medical history, functional evaluation, laboratory tests and cytokine assays (TNF-α, IFN-α, IL-6, IL-10) at hospital admission. In 19 (12.2%) of 156 COVID-19 patients, CMV reactivation was detected. Multivariate Cox regression models showed that in-hospital mortality significantly increased among CMV positive patients younger than 87 years (HR: 9.94, 95% CI: 1.66-59.50). Other factors associated with in-hospital mortality were C-reactive protein (HR: 1.17, 95% CI: 1.05-1.30), neutrophil count (HR: 1.20, 95% CI: 1.01-1.42) and clinical frailty scale (HR:1.54, 95% CI: 1.04-2.28). In patients older than 87 years, neutrophil count (HR: 1.13, 95% CI: 1.05-1.21) and age (HR: 1.15, 95% CI: 1.01-1.31) were independently associated with in-hospital mortality. CMV reactivation was also correlated with increased IFN-α and TNF-α serum levels, but not with IL-6 and IL-10 serum changes. In conclusion, CMV reactivation was an independent risk factor for in-hospital mortality in COVID-19 patients younger than 87 years old, but not in nonagenarians.

IL-6 at the center of cytokine storm: Circulating inflammation mediators as biomarkers in hospitalized COVID-19 patients.

INTRODUCTION: The management of hospitalized COVID-19 patients depends largely on controlling the intensified inflammatory response known as the cytokine storm. Candidate inflammatory cytokines can serve as new biomarkers for the management of hospitalized COVID-19 patients. METHODS: Patients (80) were recruited into three groups: room air (RA), oxygen (OX) and mechanical ventilator (MV). Blood analysis was performed for RBC, WBC, Hb, Platelets, serum albumin and creatinine, INR, PTT, and hematocrit. ELISA was used to quantify a panel of inflammatory mediators including GM-SCF, IFN-α, IFNγ, IL-1ß, IL-1R, IL-2, IL-2Ra, IL-6, IL-8, IL-10, IL-12p70, IL-13, MCP-1, MIP-1a, and TNF-α. Correlations between laboratory results and the levels of circulating inflammation mediators were investigated. RESULTS: Patients on MV had low RBC, Hb, albumin, and HCT and high WBC count, PTT, and INR when compared to RA and OX groups. A statistical positive correlation was found between WBC and the levels of IL-6 and MCP-1. RBCs correlated negatively with IL-6 and IL-10 and positively with IL-8. Higher TNF-α correlated with lower platelet counts while higher levels of IL-1Rα and IL-10 were associated with lower Hb levels. Increases in IFN-γ and TNF-α were indicative of compromised kidney functions as creatinine levels increased significantly. Most significant correlations were found between IL-6 and lab results, showing positive correlation with WBC and INR, and negative correlation with RBC, albumin, and HCT. CONCLUSIONS: Having the most significant correlations, IL-6 high levels in mechanically ventilated patients were shown to affect laboratory results, and, therefore, is suggested as a severity biomarker of COVID-19.