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

Efficacy of Alkaline Phosphatase in Critically Ill Patients with COVID-19: A Multicentre Investigator-Initiated Double-Blind Randomised Placebo-Controlled Trial

BACKGROUND

Efforts to identify therapies to treat hospitalised patients with COVID-19 are being continued. Alkaline phosphatase (AP) dephosphorylates pro-inflammatory adenosine triphosphate (ATP) into anti-inflammatory adenosine.

METHODS

In a randomised controlled trial, we investigated the safety and efficacy of AP in patients with SARS-CoV-2 infection admitted to the ICU. AP or a placebo was administered for four days following admission to the ICU. The primary outcome was the duration of mechanical ventilation. Mortality in 28 days, acute kidney injury, need for reintubation, safety, and inflammatory markers relevant to the described high cytokine release associated with SARS-CoV-2 infection were the secondary outcomes.

RESULTS

Between December 2020 and March 2022, 97 patients (of the intended 132) were included, of which 51 were randomised to AP. The trial was terminated prematurely based on meeting the threshold for futility. Compared to the placebo, AP did not affect the duration of mechanical ventilation (9.0 days vs. 9.3 days, p = 1.0). No safety issues were observed. After 28 days, mortality was 9 (18%) in the AP group versus 6 (13%) in the placebo group (p = 0.531). Additionally, no statistically significant differences between the AP and the placebo were observed for the other secondary outcomes.

CONCLUSIONS

Alkaline phosphatase (AP) therapy in COVID-19 ICU patients showed no significant benefits in this trial.

The Glycan Ectodomain of SARS-CoV-2 Spike Protein Modulates Cytokine Production and Expression of CD206 Mannose Receptor in PBMC Cultures of Pre-COVID-19 Healthy Subjects

The ability of recombinant, SARS-CoV-2 Spike (S) protein to modulate the production of two COVID-19 relevant, pro-inflammatory cytokines (IL-6 and IFN-γ) in PBMC cultures of healthy, pre-COVID-19 subjects was investigated. We observed that cytokine production was largely and diversely modulated by the S protein depending on antigen or mitogen stimulation, as well as on the protein source, insect (S-in) or human (S-hu) cells. While both proteins co-stimulated cytokine production by polyclonally CD3-activated T cells, PBMC activation by the mitogenic lectin Concanavalin A (Con A) was up-modulated by S-hu protein and down-modulated by S-in protein. These modulatory effects were likely mediated by the S glycans, as demonstrated by direct Con A-S binding experiments and use of yeast mannan as Con A binder. While being ineffective in modulating memory antigenic T cell responses, the S proteins and mannan were able to induce IL-6 production in unstimulated PBMC cultures and upregulate the expression of the mannose receptor (CD206), a marker of anti-inflammatory M2 macrophage. Our data point to a relevant role of N-glycans, particularly N-mannosidic chains, decorating the S protein in the immunomodulatory effects here reported. These novel biological activities of the S glycan ectodomain may add to the comprehension of COVID-19 pathology and immunity to SARS-CoV-2.

A clinically attenuated double-mutant of porcine reproductive and respiratory syndrome virus-2 that does not prompt overexpression of proinflammatory cytokines during co-infection with a secondary pathogen

Porcine reproductive and respiratory syndrome virus (PRRSV) is known to suppress the type I interferon (IFNs-α/β) response during infection. PRRSV also activates the NF-κB signaling pathway, leading to the production of proinflammatory cytokines during infection. In swine farms, co-infections of PRRSV and other secondary bacterial pathogens are common and exacerbate the production of proinflammatory cytokines, contributing to the porcine respiratory disease complex (PRDC) which is clinically a severe disease. Previous studies identified the non-structural protein 1β (nsp1β) of PRRSV-2 as an IFN antagonist and the nucleocapsid (N) protein as the NF-κB activator. Further studies showed the leucine at position 126 (L126) of nsp1β as the essential residue for IFN suppression and the region spanning the nuclear localization signal (NLS) of N as the NF-κB activation domain. In the present study, we generated a double-mutant PRRSV-2 that contained the L126A mutation in the nsp1β gene and the NLS mutation (ΔNLS) in the N gene using reverse genetics. The immunological phenotype of this mutant PRRSV-2 was examined in porcine alveolar macrophages (PAMs) in vitro and in young pigs in vivo. In PAMs, the double-mutant virus did not suppress IFN-β expression but decreased the NF-κB-dependent inflammatory cytokine productions compared to those for wild-type PRRSV-2. Co-infection of PAMs with the mutant PRRSV-2 and Streptococcus suis (S. suis) also reduced the production of NF-κB-directed inflammatory cytokines. To further examine the cytokine profiles and the disease severity by the mutant virus in natural host animals, 6 groups of pigs, 7 animals per group, were used for co-infection with the mutant PRRSV-2 and S. suis. The double-mutant PRRSV-2 was clinically attenuated, and the expressions of proinflammatory cytokines and chemokines were significantly reduced in pigs after bacterial co-infection. Compared to the wild-type PRRSV-2 and S. suis co-infection control, pigs coinfected with the double-mutant PRRSV-2 exhibited milder clinical signs, lower titers and shorter duration of viremia, and lower expression of proinflammatory cytokines. In conclusion, our study demonstrates that genetic modification of the type I IFN suppression and NF-κB activation functions of PRRSV-2 may allow us to design a novel vaccine candidate to alleviate the clinical severity of PRRS-2 and PRDC during bacterial co-infection.

Effect of Anti-Interleukin-6 Agents on Psychopathology in a Sample of Patients with Post-COVID-19 Syndrome: An Observational Study

Interleukin 6 (IL-6) receptor inhibitors tocilizumab and sarilumab have recently been approved for severe coronavirus disease 2019 (COVID-19). They also affect mood, even though their effect on the post-COVID-19 syndrome-related psychopathology still has to be investigated. The aim of this study was to investigate their effect on psychopathology in a sample of patients with post-COVID-19 syndrome. We included 246 patients (34% female, 66% male) aged 18-75 years who had been hospitalized for COVID. Patients were split into those who received anti-IL-6 receptor agents (Anti-IL-6-R, N = 88) and those who did not (Ctrl, N = 158). The former group was further split into those receiving tocilizumab (TOC, N = 67) and those receiving sarilumab (SAR, N = 21). Groups were compared based on clinical characteristics before and during COVID-19 as well as on physical and psychiatric symptoms after COVID-19. Ctrl had less psychiatric and physical symptoms during hospitalization and more post-COVID-19 diarrhea, headache, cough, and dyspnea upon exertion than those receiving IL-6-receptor inhibitors. Ctrl also showed greater difficulties in emotion regulation. These differences were driven by TOC vs. Ctrl, whereas differences between SAR and Ctrl or TOC did not reach significance. IL-6 receptor inhibitors are related to a lower post-COVID-19 illness burden and seem to be effective in emotion regulation. Further research is needed to confirm these findings.

Blood circulating bacterial DNA in hospitalized old COVID-19 patients

BACKGROUND

Coronavirus disease COVID-19 is a heterogeneous condition caused by SARS-CoV-2 infection. Generally, it is characterized by interstitial pneumonia that can lead to impaired gas-exchange, acute respiratory failure, and death, although a complex disorder of multi-organ dysfunction has also been described. The pathogenesis is complex, and a variable combination of factors has been described in critically ill patients. COVID-19 is a particular risk for older persons, particularly those with frailty and comorbidities. Blood bacterial DNA has been reported in both physiological and pathological conditions and has been associated with some haematological and laboratory parameters but, to date, no study has characterized it in hospitalized old COVID-19 patients The present study aimed to establish an association between blood bacterial DNA (BB-DNA) and clinical severity in old COVID-19 patients.

RESULTS

BB-DNA levels were determined, by quantitative real-time PCRs targeting the 16S rRNA gene, in 149 hospitalized older patients (age range 65-99 years) with COVID-19. Clinical data, including symptoms and signs of infection, frailty status, and comorbidities, were assessed. BB-DNA was increased in deceased patients compared to discharged ones, and Cox regression analysis confirmed an association between BB-DNA and in-hospital mortality. Furthermore, BB-DNA was positively associated with the neutrophil count and negatively associated with plasma IFN-alpha. Additionally, BB-DNA was associated with diabetes.

CONCLUSIONS

The association of BB-DNA with mortality, immune-inflammatory parameters and diabetes in hospitalized COVID-19 patients suggests its potential role as a biomarker of unfavourable outcomes of the disease, thus it could be proposed as a novel prognostic marker in the assessment of acute COVID-19 disease.

Comparison of plasma mitochondrial DNA copy number in asymptomatic and symptomatic COVID-19 patients

Introduction

Since the beginning of the COVID-19 pandemic, a wide clinical spectrum, from asymptomatic infection to mild or severe disease and death, have been reported in COVID-19 patients. Studies have suggested several possible factors, which may affect the clinical outcome of COVID-19. A pro-inflammatory state and impaired antiviral response have been suggested as major contributing factors in severe COVID-19. Considering that mitochondria have an important role in regulating the immune responses to pathogens, pro-inflammatory signaling, and cell death, it has received much attention in SARS-CoV-2 infection. Recent studies have demonstrated that high levels of cell-free mitochondrial DNA (cf-mtDNA) are associated with an increased risk of COVID-19 intensive care unit (ICU) admission and mortality. However, there have been few studies on cf-mtDNA in SARS-CoV-2 infection, mainly focusing on critically ill COVID-19 cases. In the present study, we investigated cf-mtDNA copy number in COVID-19 patients and compared between asymptomatic and symptomatic cases, and assessed the clinical values. We also determined the cf-nuclear DNA (cf-nDNA) copy number and mitochondrial transcription factor A (TFAM) mRNA level in the studied groups.

Materials and methods

Plasma and buffy coat samples were collected from 37 COVID-19 patients and 33 controls. Briefly, after total DNA extraction, plasma cf-mtDNA, and cf-nDNA copy numbers were measured by absolute qPCR using a standard curve method. Furthermore, after total RNA extraction from buffy coat and cDNA synthesis, TFAM mRNA levels were evaluated by qPCR.

Results

The results showed that cf-mtDNA levels in asymptomatic COVID-19 patients were statistically significantly higher than in symptomatic cases (p value = 0.01). However, cf-nDNA levels were higher in symptomatic patients than in asymptomatic cases (p value = 0.00). There was no significant difference between TFAM levels in the buffy coat of these two groups (p value > 0.05). Also, cf-mtDNA levels showed good diagnostic potential in COVID-19 subgroups.

Conclusion

cf-mtDNA is probably important in the outcome of SARS-CoV-2 infection due to its role in inflammation and immune response. It can also be a promising candidate biomarker for the diagnosis of COVID-19 subgroups. Further investigation will help understanding the COVID-19 pathophysiology and effective diagnostic and therapeutic strategies.

Optimizing the use of vilobelimab for the treatment of COVID-19

INTRODUCTION

On 4 April 2023i4 April 2023, the United States Food and Drug Administration issued an emergency use authorization for the use of vilobelimab (GohibicTM) for the treatment of COVID-19 in hospitalized adults when initiated within 48 hours of receiving invasive mechanical ventilation or extracorporeal membrane oxygenation.

AREAS COVERED

Vilobelimab is a human-mouse chimeric IgG4 kappa antibody that targets human complement component 5a, a part of the immune system that is thought to play an important role in the systemic inflammation due to SARS-CoV-2 infection that leads to COVID-19 disease progression.

EXPERT OPINION

A pragmatic, adaptive, randomized, multicenter phase II/III study evaluating vilobelimab for the treatment of severe COVID-19 found that patients receiving invasive mechanical ventilation and usual care who were treated with vilobelimab had a lower risk of death by day 28 and day 60 compared to those receiving placebo. This manuscript explores what is known about vilobelimab and explores how this treatment may be used in the future to treat severe COVID-19.

Quality of Life (QoL) in Patients with Chronic Inflammatory Bowel Diseases: How Much Better with Biological Drugs?

BACKGROUND

Inflammatory bowel diseases (IBDs), including ulcerative colitis (UC) and Crohn's disease (CD), are chronic and disabling diseases that affect patient health-related quality of life (HRQoL). IBD patients are frequently exposed to high levels of stress and psychological distress. Biological drugs have been proven to reduce inflammation, hospitalization, and most of the complications that characterize IBDs; their potential contribution to patients' HRQoL remains to be explored.

AIM

To evaluate and compare any change in the HRQoL and markers of inflammation in IBD patients undergoing biological drugs (infliximab or vedolizumab).

MATERIAL AND METHODS

A prospective observational study was conducted on a cohort of IBD patients, aged >18 years, who were prescribed with infliximab or vedolizumab. Demographic and disease-related data at baseline were collected. Standard hematological and clinical biochemistry parameters, including C-reactive protein (CRP), white blood cells count (WBC), erythrocytes sedimentation rate (ESR), and α1 and α2 globulins were measured after a 12-h fast at baseline (T0), after 6 weeks (T1), and at 14 weeks (T2) of biological treatment. Steroid use, disease activity as measured by the Harvey-Bradshaw index (HBI) and partial Mayo score (pMS) for the CD and UC, respectively, were also recorded at each timepoint. The Short Form 36 Health Survey (SF-36), Functional Assessment of Chronic Illness Therapy (FACIT-F), and Work Productivity and Activity Impairment-General Health Questionnaire (WPAI:GH) were administered to each patient at baseline, T1, and T2 to address the study aims.

RESULTS

Fifty eligible consecutive patients (52% with CD and 48% with UC) were included in the study. Twenty-two patients received infliximab and twenty-eight received vedolizumab. We noted a significant reduction in the CRP, WBC, α1, and α2 globulins from T0 to T2 (p = 0.046, p = 0.002, p = 0.008, and p = 0.002, respectively). Participants showed a significant decrease in steroid administration during the observation period. A significant reduction in the HBI of CD patients at all three timepoints and a similarly significant decrease in the pMS of UC patients from baseline to T1 were recorded. Statistically significant changes were observed in all questionnaires during follow-up as well as an overall improvement in the HRQoL. The interdependence analysis carried out between the biomarkers and the scores of the individual subscales showed a significant correlation between the variation (Δ) of the CRP, Hb, MCH, and MCV with physical and emotional dimensions of the SF-36 and FACIT-F tools; work productivity loss expressed by some of the WPAI:GH items negatively correlated with the ΔWBC and positively with the ΔMCV, ΔMCH, and Δ α1 globulins. A sub-analysis according to the type of treatment showed that patients receiving infliximab experienced a more pronounced improvement in their HRQoL (according to both SF-36 and FACIT-F) compared with patients receiving vedolizumab.

CONCLUSIONS

Both infliximab and vedolizumab played an important role in contributing to the improvement of the HRQoL in IBD patients by also reducing inflammation and, consequently, steroid use in patients with an active disease. HRQoL, being one of the treatment goals, should also be assessed when taking charge of IBD patients to assess their clinical response and remission. The specific correlation between the biomarkers of inflammation and life's spheres, as well as their possible role as clinical markers of HRQoL, should be further investigated.

Interferon lambda as a potential treatment for COVID-19

INTRODUCTION

Pegylated interferon lambda substantially reduced the risk of COVID-19-related hospitalizations or emergency room visits in a recent phase 3, multi-center, randomized, double-blind, placebo-controlled study of high-risk, non-hospitalized adult patients with SARS-CoV-2 infection compared to treatment with placebo.

AREAS COVERED

Interferons are a family of signaling molecules produced as part of the innate immune response to viral infections. The administration of exogenous interferon may limit disease progression in patients with COVID-19.

EXPERT OPINION

Interferons have been used to treat viral infections, including hepatitis B and hepatitis C, and malignancies such as non-Hodgkin's lymphoma, as well as the autoimmune condition multiple sclerosis. This manuscript examines what is known about the role of interferon lambda in the treatment of COVID-19, including potential limitations, and explores how this approach may be used in the future.