Cytokine Storm Signature in Patients with Moderate and Severe COVID-19

Longitudinal Changes in Peripheral and Alveolar Monocyte and Inflammatory Biomarkers are Distinct in Hypercapnia Patients Following Pulmonary Sepsis-Induced ARDS

Background

Hypercapnia, an Acute Respiratory Distress Syndrome (ARDS) complication after pulmonary sepsis, remains enigmatic in terms of its immunological mechanisms. Our study was designed to compare initial values and longitudinal changes in cellular composition and inflammatory biomarkers between pneumonia sepsis-induced ARDS patients without hypercapnia and hypercapnia patients.

Methods

Between Dec 2022-Apr 2023, we prospectively studied 61 severe pneumonia patients. Eleven non-sepsis pneumonia patients were controls; 50 patients with pulmonary sepsis met ARDS criteria, 26 among them developed hypercapnia. We collected clinical data, respiratory parameters, peripheral blood mononuclear cells (PBMCs), and bronchoalveolar lavage fluid (BALF) at Day 1 and Day 7 post-intubation. Single-cell RNA sequencing (ScRNA-seq) was performed between selected hypercapnia and non-hypercapnia patients to characterize immune and cellular profiles. Specimens were analyzed via flow cytometry and cytokine panel.

Results

By compiling clinical data and specimens, we found that hypercapnia patients with ARDS had poorer outcomes and higher mortality. At day 1, ScRNA-seq and cytometric analysis revealed increase in monocytes and activation of cytokine storm genes with elevated interleukin (IL) -1β, IL-12p40, and IL-23 in peripheral blood. In hypercapnia patients, percentage of CD14+CD16- classical monocyte and concentrations of IL-12p40 and IL-23 increased from day 1 to day 7 in both circulation and airways. However, these alterations of cellular phenotype and cytokine decreased during seven-treatment period in non-hypercapnia patients.

Conclusion

We offer novel perspectives on monocyte-centered clusters and associated biomarkers, which play a pivotal role in driving hypercapnia after pulmonary sepsis-induced ARDS. Our study provides fresh insights into the immunological mechanisms underlying hypercapnia in ARDS, laying the foundation for useful therapeutic targets to improve patient outcomes.

Elevated Levels of IL-1Ra, IL-1β, and Oxidative Stress in COVID-19: Implications for Inflammatory Pathogenesis

Background: The coronavirus-caused disease (COVID-19), first identified in China in December 2019, has spread worldwide becoming a global pandemic. Although people infected with the SARS-CoV-2 virus presented mainly respiratory and gastrointestinal symptoms, an increase in cardiovascular incidents was observed in several scientific studies. SARS-CoV-2 virus has been shown to disrupt the normal immune response leading to a dysregulation of immune system function and massive production of inflammatory cytokines commonly known as "cytokine storm". Methods: 57 patients eventually participated in the study, assigned to non-COVID (24 patients) and COVID (33 patients) groups. After signing consent to participate in the study, each patient was given a self-administered questionnaire to fill out prior to specimen collection, anthropometric measurements were taken and venous blood was collected for the following determinations: pro- and anti-inflammatory cytokines using a Bio-Plex 200 system, oxidative stress markers and basic hematological blood parameters. Results: showed statistically significant higher values of IL-1Ra and IL-1β in the COVID-19 group. Of the oxidative stress markers, only MDA levels were higher in the COVID-19 group. Conclusions: the results of our study provide evidence and support the occurrence of elevated levels of IL-1Ra, IL-1β and MDA in the COVID-19 group of patients, which are associated with a worse course and prognosis of COVID-19. A better understanding of the pathophysiology and dysregulation of the immune system associated with the cytokine storm is essential to select patients at risk and develop effective drugs and vaccines.

Long-term mitochondrial and metabolic impairment in lymphocytes of subjects who recovered after severe COVID-19

The underlying mechanisms explaining the differential course of SARS-CoV-2 infection and the potential clinical consequences after COVID-19 resolution have not been fully elucidated. As a dysregulated mitochondrial activity could impair the immune response, we explored long-lasting changes in mitochondrial functionality, circulating cytokine levels, and metabolomic profiles of infected individuals after symptoms resolution, to evaluate whether a complete recovery could be achieved. Results of this pilot study evidenced that different parameters of aerobic respiration in lymphocytes of individuals recuperated from a severe course lagged behind those shown upon mild COVID-19 recovery, in basal conditions and after simulated reinfection, and they also showed altered glycolytic capacity. The severe groups showed trends to enhanced superoxide production in parallel to lower OPA1-S levels. Unbalance of pivotal mitochondrial fusion (MFN2, OPA1) and fission (DRP1, FIS1) proteins was detected, suggesting a disruption in mitochondrial dynamics, as well as a lack of structural integrity in the electron transport chain. In serum, altered cytokine levels of IL-1β, IFN-α2, and IL-27 persisted long after clinical recovery, and growing amounts of the latter after severe infection correlated with lower basal and maximal respiration, ATP production, and glycolytic capacity. Finally, a trend for higher circulating levels of 3-hydroxybutyrate was found in individuals recovered after severe compared to mild course. In summary, long after acute infection, mitochondrial and metabolic changes seem to differ in a situation of full recovery after mild infection versus the one evolving from severe infection.

Differences in Plasma Extracellular Vesicles of Different Origin in On-Pump Versus Off-Pump Cardiac Surgery

Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) causes a systemic inflammatory response that can worsen patient outcomes. Off-pump surgery has been associated with a reduced inflammatory response. The precise mechanisms and the role of extracellular vesicles (EVs) in this context are not fully understood. This study aimed to investigate the early immune response, including main T- and B-lymphocyte subsets, cytokine profiles, and plasma EVs, in patients undergoing off-pump (n = 18) and on-pump (n = 18) CABG. Thirty-six patients undergoing isolated CABG were enrolled in this randomized control study. Pre- and 24 h postoperative blood samples were analyzed for immune cell populations, cytokine levels, and plasma EV phenotyping. Off-pump CABG triggered a milder immune response than on-pump surgery. On-pump surgery led to greater changes in circulating EVs, particularly platelet- (CD62P+), endothelial- (CD31+), and B-cell-derived (CD19+), as well as platelet- and erythrocyte-derived aggregates (CD41+CD235a+). Levels of platelet-derived EVs, expressing both constitutional and activation markers (CD41+CD62P+) decreased in both groups of patients 24 h after surgery. On-pump cardiac procedures led to an increase in T-regulatory cell-derived EVs (CD73+CD39+), suggesting a potential mechanism for immune suppression compared to off-pump surgery. There were numerous correlations between EV levels and cytokine profiles following on-pump surgery, hinting at a close relationship. Leucocyte-derived EVs exhibited positive correlations with each other and with GRO but showed negative correlations with endothelial-derived EVs (CD90+ and CD31+). Additionally, CD73+ EVs demonstrated positive correlations with platelet counts and with erythrocyte-derived CD235a+ EVs. EV changes were significantly greater after on-pump surgery, highlighting a more pronounced response to this type of surgery and emphasizing the role of EVs as regulators of post-surgical inflammation.

Tracking inflammation resolution signatures in lungs after SARS-CoV-2 omicron BA.1 infection of K18-hACE2 mice

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19), which can result in severe disease, often characterised by a 'cytokine storm' and the associated acute respiratory distress syndrome. However, many infections with SARS-CoV-2 are mild or asymptomatic throughout the course of infection. Although blood biomarkers of severe disease are well studied, less well understood are the inflammatory signatures in lung tissues associated with mild disease or silent infections, wherein infection and inflammation are rapidly resolved leading to sequelae-free recovery. Herein we described RNA-Seq and histological analyses of lungs over time in an omicron BA.1/K18-hACE2 mouse infection model, which displays these latter features. Although robust infection was evident at 2 days post infection (dpi), viral RNA was largely cleared by 10 dpi. Acute inflammatory signatures showed a slightly different pattern of cytokine signatures compared with severe infection models, and where much diminished 30 dpi and absent by 66 dpi. Cellular deconvolution identified significantly increased abundance scores for a number of anti-inflammatory pro-resolution cell types at 5/10 dpi. These included type II innate lymphoid cells, T regulatory cells, and interstitial macrophages. Genes whose expression trended downwards over 2-66 dpi included biomarkers of severe disease and were associated with 'cytokine storm' pathways. Genes whose expression trended upward during this period were associated with recovery of ciliated cells, AT2 to AT1 transition, reticular fibroblasts and innate lymphoid cells, indicating a return to homeostasis. Very few differentially expressed host genes were identified at 66 dpi, suggesting near complete recovery. The parallels between mild or subclinical infections in humans and those observed in this BA.1/K18-hACE2 mouse model are discussed with reference to the concept of "protective inflammation".

COVID-19 inflammatory signature in a Mozambican cohort: unchanged red blood series and reduced levels of IL-6 and other proinflammatory cytokines

BACKGROUND

Alterations in haematological, biochemical parameters and cytokine levels, were reported in patients with COVID-19, however, there is an underrepresentation of the African population, which could provide evidence for understanding SARS-CoV-2 pathogenesis and useful tools for clinical management of cases. In this study, we aimed to determine the haematological, biochemical and cytokine profile in Mozambican individuals with SARS-CoV-2.

METHODS

A cohort of 85 Mozambican individuals with RT-PCR SARS-CoV-2 results, was stratified into negative, asymptomatic, mild, moderate, and severe categories. Haematological, biochemical and cytokines measurement were performed on samples from the study participants. Principal component analysis (PCA) was performed to identify similar patterns among the study cases. Comparisons between groups were performed using the Kruskal-Wallis test. Receiver operating characteristic (ROC) and area under the curve (AUC) analysis were conducted to evaluate the ability of these parameters to distinguish severe from non-severe cases of SARS-CoV-2 infection.

RESULTS

SARS-CoV-2 infection was associated with a significant (p < 0.05) decrease in peripheral blood absolute counts of total lymphocytes and eosinophils, below the reference values along with no abnormal change (p > 0.05) in red blood cell count, haemoglobin, platelets and other red series parameters. At the serum level, SARS-CoV-2 infection was associated with an increase in serum levels of C-reactive protein (C-RP) and glucose above the reference values and to a significant reduction a significant (p < 0.05) reduction in levels of interferon-gamma (INF-γ), Tumour Necrosis Factor alfa (TNF-α) and the interleukin 1 beta (IL-1β) and IL-6 in severe cases, when compared to negative cases. Haematological, biochemical and cytokine profiles segregate severe from non-severe cases of COVID-19 with an excellent performance of C-RP (AUC = 0.95; p < 0.001) and good performance of lymphocytes (AUC = 0.88; p < 0.001) and IL-15 (AUC = 0.86; p < 0.001).

CONCLUSION

The lack of variation in red and platelet series, coupled with a decrease in the levels of classical pro-inflammatory in severe cases, deviates from what has been reported in other contexts suggesting, that there may be peculiarities in COVID-19 manifestation within the context of this study population. Furthermore, these results identify parameters with potential for clinical management of COVID-19 and therefore good resource allocation, particularly for severe cases.

T Regulatory Cell Subsets Do Not Restore for One Year After Acute COVID-19

COVID-19, caused by SARS-CoV-2, triggers a complex immune response, with T regulatory cells (Tregs) playing a crucial role in maintaining immune homeostasis and preventing excessive inflammation. The current study investigates the function of T regulatory cells during COVID-19 infection and the subsequent recovery period, emphasizing their impact on immune regulation and inflammation control. We conducted a comprehensive analysis of Treg subpopulations in peripheral blood samples from COVID-19 patients at different stages: acute infection, early convalescence, and long-term recovery. Flow cytometry was employed to quantify Tregs including "naïve", central memory (CM), effector memory (EM), and terminally differentiated CD45RA+ effector cells (TEMRA). Additionally, the functional state of the Tregs was assessed by the expression of purinergic signaling molecules (CD39, CD73). Cytokine profiles were assessed through multiplex analysis. Our findings indicate a significant decrease in the number of Tregs during the acute phase of COVID-19, which correlates with heightened inflammatory markers and increased disease severity. Specifically, we found a decrease in the relative numbers of "naïve" and an increase in EM Tregs, as well as a decrease in the absolute numbers of "naïve" and CM Tregs. During the early convalescent period, the absolute counts of all Treg populations tended to increase, accompanied by a reduction in pro-inflammatory cytokines. Despite this, one year after recovery, the decreased subpopulations of regulatory T cells had not yet reached the levels observed in healthy donors. Finally, we observed the re-establishment of CD39 expression in all Treg subsets; however, there was no change in CD73 expression among Tregs. Understanding these immunological changes across different T regulatory subsets and adenosine signaling pathways offers important insights into the disease's pathogenesis and provides a broader view of immune system dynamics during recovery.

Cytokine Storm in COVID-19: Exploring IL-6 Signaling and Cytokine-Microbiome Interactions as Emerging Therapeutic Approaches

IL-6 remains a key molecule of the cytokine storms characterizing COVID-19, exerting both proinflammatory and anti-inflammatory effects. Emerging research underscores the significance of IL-6 trans-signaling over classical signaling pathways, which has shifted the focus of therapeutic strategies. Additionally, the synergistic action of TNF-α and IFN-γ has been found to induce inflammatory cell death through PANoptosis, further amplifying the severity of cytokine storms. Long COVID-19 patients, as well as those with cytokine storms triggered by other conditions, exhibit distinct laboratory profiles, indicating the need for targeted approaches to diagnosis and management. Growing evidence also highlights the gut microbiota's crucial role in modulating the immune response during COVID-19 by affecting cytokine production, adding further complexity to the disease's immunological landscape. Targeted intervention strategies should focus on specific cytokine cutoffs, though accurate cytokine quantification remains a clinical challenge. Current treatment strategies are increasingly focused on inhibiting IL-6 trans-signaling, which offers promise for more precise therapeutic approaches to manage hyperinflammatory responses in COVID-19. In light of recent discoveries, this review summarizes key research findings on cytokine storms, particularly their role in COVID-19 and other inflammatory conditions. It explores emerging therapeutic strategies targeting cytokines like IL-6, TNF-α, and IFN-γ, while also addressing open questions, such as the need for better biomarkers to detect and manage cytokine storms. Additionally, the review highlights ongoing challenges in developing targeted treatments that mitigate hyperinflammation without compromising immune function, emphasizing the importance of continued research in this field.

Prospective Variation of Cytokine Trends during COVID-19: A Progressive Approach from Disease Onset until Outcome

COVID-19 is characterized by pronounced hypercytokinemia. The cytokine switch, marked by an imbalance between pro-inflammatory and anti-inflammatory cytokines, emerged as a focal point of investigation throughout the COVID-19 pandemic. However, the kinetics and temporal dynamics of cytokine release remain contradictory, making the development of new therapeutics difficult, especially in severe cases. This study collected serum samples from SARS-CoV-2 infected patients at 72 h intervals and monitored them for various cytokines at each timepoint until hospital discharge or death. Cytokine levels were analyzed based on time since symptom onset and patient outcomes. All cytokines studied prospectively were strong predictors of mortality, particularly IL-4 (AUC = 0.98) and IL-1β (AUC = 0.96). First-timepoint evaluations showed elevated cytokine levels in the mortality group (p < 0.001). Interestingly, IFN-γ levels decreased over time in the death group but increased in the survival group. Patients who died exhibited sustained levels of IL-1β and IL-4 and increased IL-6 levels over time. These findings suggest cytokine elevation is crucial in predicting COVID-19 mortality. The dynamic interplay between IFN-γ and IL-4 highlights the balance between Th1/Th2 immune responses and underscores IFN-γ as a powerful indicator of immune dysregulation throughout the infection.

Alpha-1 adrenergic antagonists and the risk of hospitalization or death in non-hospitalized patients with COVID-19: A population-based study

BACKGROUND

Alpha-1 receptor antagonists may interfere with IL-6 signaling and could therefore be a potential treatment for COVID-19. However, the effectiveness of these drugs in mitigating the risk of clinical deterioration among non-hospitalized patients with COVID-19 is unknown.

OBJECTIVES

The aim of this study is to examine the association between alpha-1 antagonist exposure and the 30-day risk of a hospital encounter or death in nonhospitalized patients with COVID-19.

METHODS

We conducted a population-based cohort study of Ontario residents aged 35 years and older who were eligible for public drug coverage and who had a positive test for SARS-CoV-2 between January 1, 2020, and March 1, 2021. We matched each individual receiving an alpha-1 antagonist at the time of their positive test with two non-exposed individuals using propensity scores. Our outcome was a composite of a hospital admission, emergency department visit, or death, 1 to 30 days following the positive test.

RESULTS

We matched 3289 alpha-1 antagonist exposed patients to 6189 unexposed patients. Overall, there was no difference in the 30-day risk of the primary outcome among patients exposed to alpha-1 antagonists at the time of their diagnosis relative to unexposed individuals (28.8% vs. 28.0%; OR 1.00, 95% CI 0.91 to 1.11). In a secondary analysis, individuals exposed to alpha-1 antagonists had a lower risk of death in the 30 days following a COVID diagnosis (OR 0.79; 95% CI 0.66 to 0.93).

CONCLUSION

Alpha-1 antagonists did not mitigate the 30-day risk of clinical deterioration in non-hospitalized patients with COVID-19. Our findings do not support the general repurposing of alpha-1 antagonists as a treatment for such patients, although there may be subgroups of patients in whom further research is warranted.

The unique metabolic and lipid profiles of patients with severe COVID-19 compared to severe community-acquired pneumonia: a potential prognostic and therapeutic target

BACKGROUND

Compare the changes and differences in metabolome and lipidome profiles among severe COVID-19 and CAP patients with ARF to identify biomarkers that could be used for personalized diagnosis, prognosis, and treatment.

RESEARCH DESIGN AND METHODS

Plasma samples were taken at hospital admission (baseline) and on the 5th day of hospitalization (follow-up) and examined by RP-LC-QTOF-MS and HILIC-LC-QTOF-MS.

RESULTS

127 patients, 17 with CAP and 110 with COVID-19, were included. The analysis revealed 87 altered metabolites, suggesting changes in the metabolism of arachidonic acid, glycerolipids, glycerophospholipids, linoleic acid, pyruvate, glycolysis, among others. Most of these metabolites are involved in inflammatory, hypoxic, and thrombotic processes. At baseline, the greatest differences were found in phosphatidylcholine (PC) 31:4 (p < 0.001), phosphoserine (PS) 34:3 (p < 0.001), and phosphatidylcholine (PC) 36:5 (p < 0.001), all of which were notably decreased in COVID-19 patients. At follow-up, the most dysregulated metabolites were monomethyl-phosphatidylethanolamine (PE-Nme) 40:5 (p < 0.001) and phosphatidylcholine (PC) 38:4 (p < 0.001).

CONCLUSIONS

Metabolic and lipidic alterations suggest inhibition of innate anti-inflammatory and anti-thrombotic mechanisms in COVID-19 patients, which might lead to increased viral proliferation, uncontrolled inflammation, and thrombi formation. Results provide novel targets for predictive biomarkers against CAP and COVID-19.

TRIAL REGISTRATION

Not applicable.

IFN Lambda Deficiency Contributes to Severe COVID-19 Outcomes

Interferons (IFNs) produced by airway epithelial cells are crucial in defending against pathogens. Fluctuations in IFN-λ levels may influence coronavirus disease 19 (COVID-19) severity. However, conflicting data have been reported regarding serum IFN-λ concentrations in COVID-19 patients. To address this, we evaluated serum IFN-λ levels over time in moderate and severe COVID-19 patients and their association with cytokine production and clinical parameters using the enzyme-linked immunosorbent assay (ELISA) and the Bio-Plex Pro Human Cytokine 17-plex Assay. Results from testing 51 COVID-19 patients showed that 68% lacked detectable serum IFN-λ. Among non-IFN-λ secretors, severe COVID-19 predominated. In contrast, IFN-λ secretors displayed stable IFN-λ levels in moderate cases, while severe cases showed a decline over time, which persisted even after recovery. A negative correlation was observed between IFN-λ levels and inflammatory markers. This, combined with an increase in tumor necrosis factor alpha (TNF-α) and clinical improvement, suggests a regulatory role for IFN-λ in promoting faster recovery. Despite this, survival rates were similar between the groups, indicating that while IFN-λ influences the course of the disease, it does not directly affect overall survival. In conclusion, IFN-λ is vital, but not unique, for the antiviral response and COVID-19 recovery. Simultaneously, serum IFN-λ deficiency signifies severe COVID-19.

Outcomes of COVID-19 in 24 hospitalized liver transplant recipients: an observational study

BACKGROUND

Although liver transplant (LT) recipients are considered a population at risk of severe features of coronavirus disease 2019 (COVID-19), data in this regard are scarce and controversial. In this study, we reported the outcome of 24 cases of LT recipients who were hospitalized due to COVID-19 and investigated the role-playing factors in the severity of the disease.

METHODS

In this single-center, analytic case-series study, eligible patients were among LT recipients who were hospitalized due to the diagnosis of COVID-19 based on positive results of polymerase chain reaction. Participants were categorized as severe COVID-19 if they were admitted to the intensive care unit, experienced respiratory failure demanding mechanical ventilation, or eventually died. Demographic and clinical data, COVID-19 symptoms and specific treatments, laboratory biomarkers, and immunosuppressive regimens and their alteration during the admission were recorded. Analysis was done using SPSS software.

RESULTS

Twenty-four hospitalized LT patients were included, of which nine had severe and fifteen had non-severe COVID-19. Out of 9 patients with severe COVID-19, four sadly died. The analysis and comparison between the two groups revealed longer hospital stays (P = 0.02), lower lymphocyte counts (P = 0.002), and higher levels of C-reactive protein (CRP) (P = 0.006) in patients with severe COVID-19. Patients with non-severe COVID-19 had higher doses of tacrolimus and mycophenolate in their baseline immunosuppressive regimen (both P = 0.02).

CONCLUSION

Lymphopenia and high CRP levels are associated with more severe forms of COVID-19 in LT patients. Mycophenolate may have protective properties against severe COVID-19. The role of severity indicators in LT patients with COVID-19 needs to be systematically recognized.

Notable correlation between serum epidermal growth factor values and inflammatory status in patients with COVID-19

INTRODUCTION

Despite its crucial role in Epidermal Growth Factor Receptor (EGFR) activation, and the resulting impact on the health-disease process, epidermal growth factor (EGF) is an underexplored molecule in relation to how its serum concentrations relate to other analytes and clinical variables in pathological contexts.

OBJECTIVE

To clarify the possible correlation between EGF and clinical and analytical variables in the context of COVID-19.

METHODS

Cross-sectional observational and analytical study, in patients with virological and clinical diagnosis of COVID-19, selected by simple random sampling, admitted between August and September 2021. UMELISA-EGF commercial kits were used.

RESULTS

Differences in overall EGF values were observed between groups (566.04 vs. 910.53 pg/ml, p = .0430). In COVID-19 patients, no notable correlations were observed for neutrophil, platelet, triglyceride or liver enzyme values (p > .05). Significant correlations were observed with the neutrophil-lymphocyte indicator (r = 0.4711, p = .0128) as well as with the platelet-lymphocyte index (r = 0.4553, p = .0155). Statistical results of multivariate regression analysis suggest NLR (β = .2232, p = .0353) and PLR (β = .2117, p = .0411) are predictors of inflammation in patients with COVID-19.

CONCLUSIONS

Serum EGF concentrations in COVID-19 correlate positively with prognostic inflammatory markers of severity and could presumably act as an independent risk factor for the development of inflammation in response to new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

COVID-19 and Long COVID: Disruption of the Neurovascular Unit, Blood-Brain Barrier, and Tight Junctions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), could affect brain structure and function. SARS-CoV-2 can enter the brain through different routes, including the olfactory, trigeminal, and vagus nerves, and through blood and immunocytes. SARS-CoV-2 may also enter the brain from the peripheral blood through a disrupted blood-brain barrier (BBB). The neurovascular unit in the brain, composed of neurons, astrocytes, endothelial cells, and pericytes, protects brain parenchyma by regulating the entry of substances from the blood. The endothelial cells, pericytes, and astrocytes highly express angiotensin converting enzyme 2 (ACE2), indicating that the BBB can be disturbed by SARS-CoV-2 and lead to derangements of tight junction and adherens junction proteins. This leads to increased BBB permeability, leakage of blood components, and movement of immune cells into the brain parenchyma. SARS-CoV-2 may also cross microvascular endothelial cells through an ACE2 receptor-associated pathway. The exact mechanism of BBB dysregulation in COVID-19/neuro-COVID is not clearly known, nor is the development of long COVID. Various blood biomarkers could indicate disease severity and neurologic complications in COVID-19 and help objectively diagnose those developing long COVID. This review highlights the importance of neurovascular and BBB disruption, as well as some potentially useful biomarkers in COVID-19, and long COVID/neuro-COVID.

Bronchial Asthma and COVID-19: Etiology, Pathological Triggers, and Therapeutic Considerations

Bronchial asthma (BA) continues to be a difficult disease to diagnose. Various factors have been described in the development of BA, but to date, there is no clear evidence for the etiology of this chronic disease. The emergence of COVID-19 has contributed to the pandemic course of asthma and immunologic features. However, there are no unambiguous data on asthma on the background and after COVID-19. There is correlation between various trigger factors that provoke the development of bronchial asthma. It is now obvious that the SARS-CoV-2 virus is one of the provoking factors. COVID-19 has affected the course of asthma. Currently, there is no clear understanding of whether asthma progresses during or after COVID-19 infection. According to the results of some studies, a significant difference was identified between the development of asthma in people after COVID-19. Mild asthma and moderate asthma do not increase the severity of COVID-19 infection. Nevertheless, oral steroid treatment and hospitalization for severe BA were associated with higher COVID-19 severity. The influence of SARS-CoV-2 infection is one of the protective factors. It causes the development of severe bronchial asthma. The accumulated experience with omalizumab in patients with severe asthma during COVID-19, who received omalizumab during the pandemic, has strongly suggested that continued treatment with omalizumab is safe and may help prevent the severe course of COVID-19. Targeted therapy for asthma with the use of omalizumab may also help to reduce severe asthma associated with COVID-19. However, further studies are needed to prove the effect of omalizumab. Data analysis should persist, based on the results of the course of asthma after COVID-19 with varying degrees of severity.

Immunomodulation of adipose-derived mesenchymal stem cells on peripheral blood mononuclear cells in colorectal cancer patients with COVID-19

BACKGROUND

Accumulating evidence has shown that adipose tissue-derived mesenchymal stem cells (ADSCs) are an effective therapeutic approach for managing coronavirus disease 2019 (COVID-19); however, further elucidation is required to determine their underlying immunomodulatory effect on the mRNA expression of T helper cell-related transcription factors (TFs) and cytokine release in peripheral blood mononuclear cells (PBMCs).

AIM

To investigate the impact of ADSCs on the mRNA expression of TFs and cytokine release in PBMCs from colorectal cancer (CRC) patients with severe COVID-19 (CRC+ patients).

METHODS

PBMCs from CRC+ patients (PBMCs-C+) and age-matched CRC patients (PBMCs-C) were stimulated and cultured in the presence/absence of ADSCs. The mRNA levels of T-box TF TBX21 (T-bet), GATA binding protein 3 (GATA-3), RAR-related orphan receptor C (RORC), and forkhead box P3 (FoxP3) in the PBMCs were determined by reverse transcriptase-polymerase chain reaction. Culture supernatants were evaluated for levels of interferon gamma (IFN-γ), interleukin 4 (IL-4), IL-17A, and transforming growth factor beta 1 (TGF-β1) using an enzyme-linked immunosorbent assay.

RESULTS

Compared with PBMCs-C, PBMCs-C+ exhibited higher mRNA levels of T-bet and RORC, and increased levels of IFN-γ and IL-17A. Additionally, a significant decrease in FoxP3 mRNA and TGF-β1, as well as an increase in T-bet/GATA-3, RORC/FoxP3, IFN-γ/IL-4, and IL-17A/TGF-β1 ratios were observed in PBMCs-C+. Furthermore, ADSCs significantly induced a functional regulatory T cell (Treg) subset, as evidenced by an increase in FoxP3 mRNA and TGF-β1 release levels. This was accompanied by a significant decrease in the mRNA levels of T-bet and RORC, release of IFN-γ and IL-17A, and T-bet/GATA-3, RORC/FoxP3, IFN-γ/IL-4, and IL-17A/TGF-β1 ratios, compared with the PBMCs-C+alone.

CONCLUSION

The present in vitro studies showed that ADSCs contributed to the immunosuppressive effects on PBMCs-C+, favoring Treg responses. Thus, ADSC-based cell therapy could be a beneficial approach for patients with severe COVID-19 who fail to respond to conventional therapies.

Multi-cohort study on cytokine and chemokine profiles in the progression of COVID-19

Various substances in the blood plasma serve as prognostic indicators of the progression of COVID-19. Consequently, multi-omics studies, such as proteomic and metabolomics, are ongoing to identify accurate biomarkers. Cytokines and chemokines, which are crucial components of immune and inflammatory responses, play pivotal roles in the transition from mild to severe illness. To determine the relationship between plasma cytokines and the progression of COVID-19, we used four study cohorts to perform a systematic study of cytokine levels in patients with different disease stages. We observed differential cytokine expression between patients with persistent-mild disease and patients with mild-to-severe transformation. For instance, IL-4 and IL-17 levels significantly increased in patients with mild-to-severe transformation, indicating differences within the mild disease group. Subsequently, we analysed the changes in cytokine and chemokine expression in the plasma of patients undergoing two opposing processes: the transition from mild to severe illness and the transition from severe to mild illness. We identified several factors, such as reduced expression of IL-16 and IL-18 during the severe phase of the disease and up-regulated expression of IL-10, IP-10, and SCGF-β during the same period, indicative of the deterioration or improvement of patients' conditions. These factors obtained from fine-tuned research cohorts could provide auxiliary indications for changes in the condition of COVID-19 patients.

Lymphocyte B Subtypes in Peripheral Blood: A Prognostic Biomarker for COVID-19 Patients

BACKGROUND

In view of the scientific gap in knowledge of the involvement of the B-cell compartment and clinical prognostic in SARS-CoV-2 infection, this work aims to evaluate the B-cell subsets and the presence of specific IgM and IgG, as well as neutralizing antibodies against SARS-CoV-2, in unvaccinated patients diagnosed with COVID-19.

METHODS

This study included 133 patients with COVID-19. Cellular components were assessed by flow cytometry, and immunoglobulin levels and reactivity were measured by indirect enzyme-linked immunosorbent assay.

RESULTS

Our results showed no changes in less differentiated B cells. However, non-switched memory B cells (NS-MBCs) and class-switched memory B cells (CS-MBCs) were reduced in the patients with moderate disease. Also, plasmablasts and double-negative (DN) or "atypical" memory B cells were increased in groups of patients with moderate to critical conditions. In addition, the production of IgM, IgG, and neutralizing antibodies against SARS-CoV-2 demonstrated a positive correlation between the positivity of antibodies against SARS-CoV-2 and disease severity. Besides being related to the development of a more severe course of the disease, the increase in DN B-cell count also contributed to a poorer disease outcome in patients with a higher percentage of these cells. On the other hand, we observed an increase in the absolute number of CS-MBCs in patients with greater chances of survival.

CONCLUSIONS

This study demonstrates that the B-cell compartment may contribute to the development of clinical symptoms of COVID-19, with changes in B-cell subset counts linked to disease course and patient prognosis.

Characteristics of innate, humoral and cellular immunity in children with non-severe SARS-CoV-2 infection

The symptoms of children infected with SARS-CoV-2 are mainly asymptomatic, mild, moderate, and a few severe cases. To understand the immune response characteristics of children infected with SARS-COV-2 who do not develop severe cases, 82 children infected with the SARS-CoV-2 delta strain were recruited in this study. Our results showed that high levels of IgG, IgM, and neutralization antibodies appeared in children infected with SARS-CoV-2. SARS-CoV-2 induced upregulation of both pro-inflammatory factors including TNF-α and anti-inflammatory factors including IL-4 and IL-13 in the children, even IL-10. The expression of INF-α in infected children also showed a significant increase compared to healthy children. However, IL-6, one of the important inflammatory factors, did not show an increase in infected children. It is worth noting that a large number of chemokines reduced in the SARS-CoV-2-infected children. Subsequently, TCR Repertoire, TCRβ bias, and preferential usage were analyzed on data of TCR next-generation sequencing from 8 SARS-CoV-2-infected children and 8 healthy controls. We found a significant decrease in TCR clonal diversity and a significant increase in TCR clonal expansion in SARS-CoV-2-infected children compared to healthy children. The most frequent V and J genes in SARS-CoV-2 children were TRBV28 and TRBJ2-1. The most frequently VβJ gene pairing in SARS-CoV-2 infected children was TRBV20-1-TRBJ2-1. The strong antiviral antibody levels, low expression of key pro-inflammatory factors, significant elevation of anti-inflammatory factors, and downregulation of many chemokines jointly determine that SARS-CoV-2-infected children rarely develop severe cases. Overall, our findings shed a light on the immune response of non-severe children infected with SARS-CoV-2.

COVID-19 Pneumonia and Cytokine Storm Syndrome

Virus-associated cytokine storm syndrome (CSS) has been recognized for a long time and the classic viruses associated are the herpes viruses EBV, CMV, and HHV-8 as described in chapters IVa,b. In addition, pandemic viruses such as influenza, SARS, and MERS can result in severe CSS that might ultimately lead to severe acute respiratory distress syndrome (ARDS) and death [1-3]. A new pandemic caused by SARS-CoV-2 that started in 2019 has defined another chapter in the virus-associated CSS. The clinical spectrum of SARS-CoV-2 infection has many faces. In most people, it will be asymptomatic, but it can also result in severe COVID-19 pneumonia, ARDS, and multiorgan failure depending on age, comorbidities, and immune status [4]. In addition, this pandemic has known many different stages and developed in a unique way in the first 2 years. It started in a setting where there was no immunity to the virus and after a year, highly effective vaccines were introduced and herd immunity built up over time. However, vaccine effectiveness was waning over time depending on multiple factors, and novel variant strains of the virus circulated across different areas in the world. Antiviral therapy was developed and introduced, and treatment changed from giving no immunomodulatory treatment, followed by the introduction of corticosteroids [5], and later the addition of more targeted strategies such as JAK inhibitors [6] and blocking IL-6 signaling [7]. Therefore, the scientific literature published on COVID-19 must be seen in the context of a highly dynamic and rapidly changing pandemic, making it difficult to compare results from early studies to more recent reports even within 2 years. Still, a lot has been learned over a very short period. It has become apparent that severe COVID-19 is predominantly a disease of immune dysregulation with components that can be defined as CSS. It has unique features and overlapping characteristics with other CSSs, and immunological treatment addressing the CSS has been extensively explored, which will be described here.

Sarcoidosis-related autoimmune inflammation in COVID-19 convalescent patients

Currently, there are a large number of reports about the development of autoimmune conditions after COVID-19. Also, there have been cases of sarcoid-like granulomas in convalescents as a part of the post-COVID-19 syndrome. Since one of the etiological theories of sarcoidosis considers it to be an autoimmune disease, we decided to study changes in the adaptive humoral immune response in sarcoidosis and SARS-CoV-2 infection and to find out whether COVID-19 can provoke the development of sarcoidosis. This review discusses histological changes in lymphoid organs in sarcoidosis and COVID-19, changes in B cell subpopulations, T-follicular helper cells (Tfh), and T-follicular regulatory cells (Tfr), and analyzes various autoantibodies detected in these pathologies. Based on the data studied, we concluded that SARS-CoV-2 infection may cause the development of autoimmune pathologies, in particular contributing to the onset of sarcoidosis in convalescents.

Ventilatory support and inflammatory peptides in hospitalised patients with COVID-19: A prospective cohort trial

PURPOSE

Several studies have shown that SARS-CoV-2 can induce a massive release of cytokines which contributes to disease severity and mortality. Therefore, cytokine levels in the serum may help to predict disease severity and survival in COVID-19 patients.

METHODS

In this prospective trial, 88 patients who were hospitalised for COVID-19 were enrolled. Blood samples for serum peptide measurements were taken at the time closest to hospitalisation, at day 5, 9 and 13 (±1). The concentrations of cytokines (IL-1α, IL-1β, IL-1RA, IL-6, L-7, L-10, IFN-γ and TNF-α), chemokines (CCL-3, CCL-4 and CCL-7) and growth factors (G-CSF, GM-CSF and VEGF) were assessed and correlated with the type of ventilation, occurrence of consolidations on imaging and the level of care.

RESULTS

COVID-19 patients (median age 68 years, IQR 55-77) stayed in hospital between 5-171 days. Compared to patients in the general care unit, patients in the intermediate care unit (IMCU) and intensive care unit (ICU) presented significantly elevated serum IL-6 (p = 0.004) and lower IFN-γ levels (p = 0.005), respectively. The peak inspiratory pressure in ventilated patients correlated positively with IL-1RA, G-CSF and inversely with IFN-γ serum levels (all p<0.05). VEGF serum levels inversely correlated with the fraction of inspired oxygen in patients receiving high-flow nasal canula oxygen therapy (p = 0.047). No significant correlation between serum concentrations of the measured peptides and the type of ventilation, occurrence of radiological consolidations or in-hospital mortality has been observed.

CONCLUSION

IL1-RA, IL-6, IFN-γ, G-CSF, CCL-7 and VEGF serum levels could prove helpful as biomarkers to assess disease severity and the need for intensive care in COVID-19 patients.

Chronic alcohol use primes bronchial cells for altered inflammatory response and barrier dysfunction during SARS-CoV-2 infection

Alcohol use disorder (AUD) is a significant public health concern and people with AUD are more likely to develop severe acute respiratory distress syndrome (ARDS) in response to respiratory infections. To examine whether AUD was a risk factor for more severe outcome in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we examined early responses to infection using cultured differentiated bronchial epithelial cells derived from brushings obtained from people with AUD or without AUD. RNA-seq analysis of uninfected cells determined that AUD cells were enriched for expression of epidermal genes as compared with non-AUD cells. Bronchial epithelial cells from patients with AUD showed a significant decrease in barrier function 72 h postinfection, as determined by transepithelial electrical resistance. In contrast, barrier function of non-AUD cells was enhanced 72 h after SARS-CoV-2 infection. AUD cells showed claudin-7 that did not colocalize with zonula occludens-1 (ZO-1), indicative of disorganized tight junctions. However, both AUD and non-AUD cells showed decreased β-catenin expression following SARS-CoV-2 infection. To determine the impact of AUD on the inflammatory response to SARS-CoV-2 infection, cytokine secretion was measured by multiplex analysis. SARS-CoV-2-infected AUD bronchial cells had enhanced secretion of multiple proinflammatory cytokines including TNFα, IL-1β, and IFNγ as opposed to non-AUD cells. In contrast, secretion of the barrier-protective cytokines epidermal growth factor (EGF) and granulocyte macrophage-colony stimulating factor (GM-CSF) was enhanced for non-AUD bronchial cells. Taken together, these data support the hypothesis that AUD is a risk factor for COVID-19, where alcohol primes airway epithelial cells for increased inflammation and increased barrier dysfunction and increased inflammation in response to infection by SARS-CoV-2.NEW & NOTEWORTHY Alcohol use disorder (AUD) is a significant risk factor for severe acute respiratory distress syndrome. We found that AUD causes a phenotypic shift in gene expression in human bronchial epithelial cells, enhancing expression of epidermal genes. AUD cells infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had higher levels of proinflammatory cytokine secretion and barrier dysfunction not present in infected non-AUD cells, consistent with increased early COVID-19 severity due to AUD.

CXCL10 May Be Responsible for Susceptibility to Pulmonary Embolism in COVID-19 Patients

Background

Although the potential of coronavirus disease 2019 (COVID-19) patients to develop pulmonary embolism (PE) is widely recognized, the underlying mechanism has not been completely elucidated. This study aimed to identify genes common to COVID-19 and PE to reveal the underlying pathogenesis of susceptibility to PE in COVID-19 patients.

Methods

COVID-19 genes were obtained from the GEO database and the OMIM, CTD, GeneCards, and DisGeNET databases; PE genes were obtained from the OMIM, CTD, GeneCards, and DisGeNET databases. We overlapped the genes of COVID-19 and PE to obtain common genes for additional analysis, including functional enrichment, protein-protein interaction, and immune infiltration analysis. Hub genes were identified using cytoHubba, a plugin of Cytoscape, and validated using the independent datasets GSE167000 and GSE13535. The genes validated by the above datasets were further validated in clinical samples.

Results

We obtained 36 genes shared by PE and COVID-19. Functional enrichment and immune infiltration analyses revealed the involvement of cytokines and immune activation. Five genes (CCL2, CXCL10, ALB, EGF, and MKI67) were identified as hub genes common to COVID-19 and PE. CXCL10 was validated in both independent datasets (GSE167000 and GSE13535). Serum levels of CXCL10 in the COVID-19 group and the COVID-19 combined with PE group were significantly higher than those in the healthy control group (P<0.001). In addition, there were significant differences between the COVID-19 group and the COVID-19 combined with PE group (P<0.01).

Conclusion

Our study reveals common genes shared by PE and COVID-19 and identifies CXCL10 as a possible cause of susceptibility to PE in COVID-19 patients.

Cognitive, behavioral, neuroimaging and inflammatory biomarkers after hospitalization for covid-19 in Brazil

Post-COVID-19 Condition (PCC) refers to a multisystemic syndrome that persists for months after SARS-CoV-2 infection. Cognitive deficits, fatigue, depression, and anxiety are common manifestations of the condition, but the underlying mechanisms driving these long-lasting neuropsychiatric features are still unclear. We conducted a prospective multi-method investigation of post-hospitalization COVID-19 patients in Rio de Janeiro, Brazil. After months from hospital admission (mean = 168.45 ± 90.31 days; range = 75.00-365.00 days), COVID-19 survivors (n = 72) presented significant difficulties in tests tapping global cognition, episodic memory, working memory and inhibitory control relative to controls and to validated normative scores. A considerable proportion of participants suffered from fatigue (36.1 %), anxiety (27.8 %), and depressive symptoms (43.1 %). Elevated blood levels of TNF-α, during hospitalization, and TNF-α and IL-1β, at follow-up, correlated with changes in brain microstructural diffusion indices (β = 0.144, p = 0.005). These neuroimaging markers were associated with decreased episodic memory (β = -0.221, p = 0.027), working memory (β = -0.209, p = 0.034) and inhibitory control (β = -0.183, p = 0.010) at follow-up. Severity of depressive symptoms correlated with deficits in global cognition in post-COVID-19 cases (β = -0.366, p = 0.038). Our study provides preliminary evidence that long-term cognitive dysfunction following COVID-19 may be mediated by brain microstructural damage, triggered by persistent neuroinflammation. In addition, depressive symptoms may contribute to prolongated global cognitive impairments in those cases.

Dexamethasone impairs the expression of antimicrobial mediators in lipopolysaccharide-activated primary macrophages by inhibiting both expression and function of interferon β

Glucocorticoids potently inhibit expression of many inflammatory mediators, and have been widely used to treat both acute and chronic inflammatory diseases for more than seventy years. However, they can have several unwanted effects, amongst which immunosuppression is one of the most common. Here we used microarrays and proteomic approaches to characterise the effect of dexamethasone (a synthetic glucocorticoid) on the responses of primary mouse macrophages to a potent pro-inflammatory agonist, lipopolysaccharide (LPS). Gene ontology analysis revealed that dexamethasone strongly impaired the lipopolysaccharide-induced antimicrobial response, which is thought to be driven by an autocrine feedback loop involving the type I interferon IFNβ. Indeed, dexamethasone strongly and dose-dependently inhibited the expression of IFNβ by LPS-activated macrophages. Unbiased proteomic data also revealed an inhibitory effect of dexamethasone on the IFNβ-dependent program of gene expression, with strong down-regulation of several interferon-induced antimicrobial factors. Surprisingly, dexamethasone also inhibited the expression of several antimicrobial genes in response to direct stimulation of macrophages with IFNβ. We tested a number of hypotheses based on previous publications, but found that no single mechanism could account for more than a small fraction of the broad suppressive impact of dexamethasone on macrophage type I interferon signaling, underlining the complexity of this pathway. Preliminary experiments indicated that dexamethasone exerted similar inhibitory effects on primary human monocyte-derived or alveolar macrophages.

Circulating CD8+ T Cell Subsets in Primary Sjögren's Syndrome

Currently, multiple studies have indicated that CD8+ T lymphocytes play a role in causing damage to the exocrine glands through acinar injury in primary Sjögren's syndrome (pSS). The aim of this research was to assess the imbalance of circulating CD8+ T cell subsets. We analyzed blood samples from 34 pSS patients and 34 healthy individuals as controls. We used flow cytometry to enumerate CD8+ T cell maturation stages, using as markers CD62L, CD28, CD27, CD4, CD8, CD3, CD45RA and CD45. For immunophenotyping of 'polarized' CD8+ T cell subsets, we used the following monoclonal antibodies: CXCR5, CCR6, CXCR3 and CCR4. The findings revealed that both the relative and absolute numbers of 'naïve' CD8+ T cells were higher in pSS patients compared to the healthy volunteers. Conversely, the proportions of effector memory CD8+ T cells were notably lower. Furthermore, our data suggested that among patients with pSS, the levels of cytotoxic Tc1 CD8+ T cells were reduced, while the frequencies of regulatory cytokine-producing Tc2 and Tc17 CD8+ T cells were significantly elevated. Simultaneously, the Tc1 cell subsets displayed a negative correlation with immunoglobulin G, rheumatoid factor, the Schirmer test and unstimulated saliva flow. On the other hand, the Tc2 cell subsets exhibited a positive correlation with these parameters. In summary, our study indicated that immune dysfunction within CD8+ T cells, including alterations in Tc1 cells, plays a significant role in the development of pSS.

Disrupted epithelial permeability as a predictor of severe COVID-19 development

BACKGROUND

An impaired epithelial barrier integrity in the gastrointestinal tract is important to the pathogenesis of many inflammatory diseases. Accordingly, we assessed the potential of biomarkers of epithelial barrier dysfunction as predictive of severe COVID-19.

METHODS

Levels of bacterial DNA and zonulin family peptides (ZFP) as markers of bacterial translocation and intestinal permeability and a total of 180 immune and inflammatory proteins were analyzed from the sera of 328 COVID-19 patients and 49 healthy controls.

RESULTS

Significantly high levels of circulating bacterial DNA were detected in severe COVID-19 cases. In mild COVID-19 cases, serum bacterial DNA levels were significantly lower than in healthy controls suggesting epithelial barrier tightness as a predictor of a mild disease course. COVID-19 patients were characterized by significantly elevated levels of circulating ZFP. We identified 36 proteins as potential early biomarkers of COVID-19, and six of them (AREG, AXIN1, CLEC4C, CXCL10, CXCL11, and TRANCE) correlated strongly with bacterial translocation and can be used to predict and discriminate severe cases from healthy controls and mild cases (area under the curve (AUC): 1 and 0.88, respectively). Proteomic analysis of the serum of 21 patients with moderate disease at admission which progressed to severe disease revealed 10 proteins associated with disease progression and mortality (AUC: 0.88), including CLEC7A, EIF4EBP1, TRANCE, CXCL10, HGF, KRT19, LAMP3, CKAP4, CXADR, and ITGB6.

CONCLUSION

Our results demonstrate that biomarkers of intact or defective epithelial barriers are associated with disease severity and can provide early information on the prediction at the time of hospital admission.

Elevated Levels of Cytotoxicity, Cytokines, and Anti-SARS-CoV-2 Antibodies in Mild Cases of COVID-19

Current evidence shows higher production of cytokines and antibodies against severe acute respiratory coronavirus 2 (SARS-CoV-2) in severe and critical cases of Coronavirus Disease 2019 (COVID-19) in comparison with patients with moderate or mild disease. A recent hypothesis proposes an important role of genotoxicity and cytotoxicity in the induction of the cytokine storm observed in some patients at later stages of the disease. Interestingly, in this study, we report significantly higher levels of interleukin (IL)-1β, IL-6, MCP-1, and IL-4 cytokines in mild COVID-19 patients versus severe cases, as well as a high frequency of karyorrhexis (median [Me] = 364 vs. 20 cells) and karyolysis (Me = 266 vs. 52 cells) in the mucosal epithelial cells of both groups of patients compared with uninfected individuals. Although we observed higher levels of anti-SARS-CoV-2 IgM and IgG antibodies in COVID-19 patients, IgM antibodies were significantly higher only in mild cases, for the N and the S viral antigens. High levels of IgG antibodies were observed in both mild and severe cases. Our results showed elevated concentrations of proinflammatory and anti-inflammatory cytokines in mild cases, which may reflect an active innate immune response and could be related to the higher IgM and IgG antibody levels found in those patients. In addition, we found that SARS-CoV-2 infection induces cytotoxic damage in the oral mucosa, highlighting the importance of studying the genotoxic and cytotoxic events induced by infection and its role in the pathophysiology of COVID-19.

SARS-CoV-2 specific T-cell humoral response assessment after COVID-19 vaccination using a rapid direct real-time PCR amplification

OBJECTIVES

The SARS-CoV-2 immune response is mediated by both humoral and cellular immunity. In this study, SARS-CoV-2 specific cellular immunity was tested by a novel direct real-time PCR (dRT-PCR) assay, targeting mRNA of CXCL10, and compared with respect to an ELISA measuring interferon gamma (IFN-γ) release.

METHODS

Whole blood (Li-He) and serum samples were collected from 92 healthcare workers (HCW), with three doses of homologous (Pfizer/BioNTech, n=74) or heterologous (Pfizer/BioNTech and Vaxzevria or Moderna, n=18) vaccinations. Li-He samples were incubated with SCV2 PANEL-1-T-ACTIVATION (Hyris srl, Lodi, Italy), or CoV-2 IGRA TUBE ELISA (Euroimmune, Lubeck, Germany). CXCL10 mRNA expression was analyzed by bCube/bApp (Hyris), while IFN-γ was evaluated by quant-T-Cell SARS-CoV-2 ELISA (Euroimmune). Anti-SARS-CoV-2 S-RBD IgG levels were measured in sera using a CLIA assay (Snibe, Shenzen, China).

RESULTS

Imprecision of dRT-PCR assay was found to be satisfactory, and the two methods for measuring T cell immunity to SARS-CoV-2 peptides agreed in 82/87 (94.2%) of results. At qualitative dRT-PCR analyses, 81 subjects (93.2%) resulted as reactive to SARS-CoV-2 peptides, 3 (3.4%) were borderline and 3 were negative (3.4%). At univariate and multivariate analyses of quantitative dRT-PCR mRNA of CXCL10 and IFN-γ release results showed no difference between HCW with previous infection, homologous/heterologous vaccination, or demographical features. Anti-SARS-CoV-2 S-RBD IgG was associated with the previous infection and the time between the last vaccination or positivity.

CONCLUSIONS

Direct RT-PCR appeared accurate for determining the presence or absence of immunoreactivity of SARS-CoV-2 specific T cells, especially when rapid analyses are required, such as for organ transplantation.

Tuberculosis and COVID-19 Dually Affect Human Th17 Cell Immune Response

COVID-19 infection not only profoundly impacts the detection of tuberculosis infection (Tbc) but also affects modality in tuberculosis patient immune response. It is important to determine immune response alterations in latent tuberculosis infection as well as in SARS-CoV-2-infected tuberculosis patients. Such changes may have underlying effects on the development and course of further tuberculosis. Here, we aimed to review the characteristics of immune response in TB patients or convalescent COVID-19 patients with latent TB infection (LTBI).

MATERIALS AND METHODS

We analyzed the features of immune response in tuberculosis and COVID-19 patients. For this, we analyzed publications released from December 2019 to March 2023; those which were published in accessible international databases ("Medline", "PubMed", "Scopus") and with keywords such as "COVID-19", "SARS-CoV-2", "tuberculosis", "pulmonary tuberculosis", "latent tuberculosis infection", "Treg", "follicular Treg", and "Treg subsets", we considered.

RESULTS

Through our analysis, we found that tuberculosis patients who had been infected with COVID-19 previously and elevated Th1 and Th2 cell levels. High levels of Th1 and Th2 cells may serve as a positive marker, characterizing activated immune response during TB infection. COVID-19 or post-COVID-19 subjects showed decreased Th17 levels, indicating a lack of tuberculosis development. Moreover, the typical course of tuberculosis is associated with an increase in Treg level, but COVID-19 contributes to a hyperinflammatory response.

CONCLUSION

According to the data obtained, the course of tuberculosis proceeds in a dissimilar way due to the distinct immune response, elicited by SARS-CoV-2. Importantly, the development of active tuberculosis with a severe course is associated with a decline in Treg levels. Both pathogens lead to disturbed immune responses, increasing the risk of developing severe TB. The insights and findings of this paper may be used to improve the future management of individuals with latent and active tuberculosis.

Early Cytokine Signatures of Hospitalized Mild and Severe COVID-19 Patients: A Prospective Observational Study

Background

The severe manifestation of coronavirus disease 2019 (COVID-19) is known to be mediated by several cytokines and chemokines. The study aimed to compare the early cytokine profile of mild and severe COVID-19 patients to that with COVID-19-like symptoms and tested negative for Severe Acute Respiratory Syndrome Coronavirus-2 in the Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) test.

Methods

This was a prospective, observational study on COVID-19 patients admitted to King Khalid University Hospital, King Saud University Medical City from June to November 2020. Clinical and biochemical data were collected from hospital charts. Blood samples were collected at the time of hospital admission to measure cytokines. A Cytokine and Growth Factor High-Sensitivity Array was used to quantitatively measure cytokines.

Results

The study included 202 RT-PCR-positive individuals and 61 RT-PCR-negative individuals. C-Reactive protein (CRP) and Interleukin-10 (IL-10) levels were found significantly elevated in the RT-PCR positive group compared to the RT-PCR negative group (p=0.001). Patients with severe COVID-19 had significantly longer median hospital stays than those with mild COVID-19 cases (7 vs 6 days). They also had higher CRP and Vascular Endothelial Growth Factor (VEGF) levels and lower Interleukin-4 (IL-4) levels compared to the mild cases. CRP, interleukin-6, IL-10, VEGF, and Monocyte Chemoattractant Protein-1 (MCP-1) levels were significantly elevated in men and IL-10 was significantly higher and interleukin-8 was significantly lower in women compared to negative controls. Elevated Interferon-ɣ (IFN-γ) and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital.

Conclusion

CRP and IL-10 levels were elevated in the RT-PCR positive group. People with severe COVID-19 had higher CRP and VEGF levels and lower IL-4 levels. Elevated IFN-γ and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital.

Temporal and Spatial Patterns of Inflammation and Tissue Injury in Patients with Postoperative Respiratory Failure after Lung Resection Surgery: A Nested Case-Control Study

Thoracic surgeries involving resection of lung tissue pose a risk of severe postoperative pulmonary complications, including acute respiratory distress syndrome (ARDS) and respiratory failure. Lung resections require one-lung ventilation (OLV) and, thus, are at higher risk of ventilator-induced lung injury (VILI) attributable to barotrauma and volutrauma in the one ventilated lung, as well as hypoxemia and reperfusion injury on the operated lung. Further, we also aimed to assess the differences in localized and systemic markers of tissue injury/inflammation in those who developed respiratory failure after lung surgery versus matched controls who did not develop respiratory failure. We aimed to assess the different inflammatory/injury marker patterns induced in the operated and ventilated lung and how this compared to the systemic circulating inflammatory/injury marker pattern. A case-control study nested within a prospective cohort study was performed. Patients with postoperative respiratory failure after lung surgery (n = 5) were matched with control patients (n = 6) who did not develop postoperative respiratory failure. Biospecimens (arterial plasma, bronchoalveolar lavage separately from ventilated and operated lungs) were obtained from patients undergoing lung surgery at two timepoints: (1) just prior to initiation of OLV and (2) after lung resection was completed and OLV stopped. Multiplex electrochemiluminescent immunoassays were performed for these biospecimen. We quantified 50 protein biomarkers of inflammation and tissue injury and identified significant differences between those who did and did not develop postoperative respiratory failure. The three biospecimen types also display unique biomarker patterns.

Clinical Characteristics and Serum Cytokines Profiling in Hospitalized COVID-19 Patients in Lebanon

Since its emergence, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains a public health threat worldwide. While the majority of patients recover in 3-4 weeks, complications in severely ill patients, including acute respiratory distress syndrome, cardiac injury, thrombosis, and sepsis, can lead to death. Several biomarkers, in addition to cytokine release syndrome (CRS), have been associated with severe and fatal outcomes in coronavirus disease 2019 (COVID-19) patients. The aim of this study is to assess clinical characteristics and cytokines profiles in hospitalized COVID-19 patients in Lebanon. A total of 51 hospitalized COVID-19 patients were recruited between February 2021 and May 2022. Clinical data and sera were collected at two time points: at hospital presentation (T0) and last collected results during hospitalization (T1). Our results showed that 49% of participants were >60 years with males accounting for the majority (72.5%). Hypertension, followed by diabetes and dyslipidemia, were the most frequent comorbid conditions among study participants accounting for 56.9% and 31.4%, respectively. Chronic obstructive pulmonary disease (COPD) was the only significantly different comorbid condition between intensive care unit (ICU) and non-ICU patients. Our results also showed that the median level of D-dimer was significantly elevated among patients in ICU and those who died compared to non-ICU patients and those who survived. Moreover, C-reactive protein (CRP) levels were significantly higher at T0 compared to T1 in ICU and non-ICU patients. The median level of IL-12p70 was significantly higher in patients >60 years compared to those ≤60 years (p = 0.0209). Our data are in agreement with previous reports suggesting the importance of IL-6, CRP, and IL-12p70 in the assessment of risk of severe disease and mortality.

SARS-CoV-2 Systemic Effects: New Clues

To date, much discussion has been had on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lung infection associated with COVID-19 onset, of which the major manifestation is characterized by a "cytokine storm" [...].

Explanatory predictive model for COVID-19 severity risk employing machine learning, shapley addition, and LIME

The rapid spread of SARS-CoV-2 threatens global public health and impedes the operation of healthcare systems. Several studies have been conducted to confirm SARS-CoV-2 infection and examine its risk factors. To produce more effective treatment options and vaccines, it is still necessary to investigate biomarkers and immune responses in order to gain a deeper understanding of disease pathophysiology. This study aims to determine how cytokines influence the severity of SARS-CoV-2 infection. We measured the plasma levels of 48 cytokines in the blood of 87 participants in the COVID-19 study. Several Classifiers were trained and evaluated using Machine Learning and Deep Learning to complete missing data, generate synthetic data, and fill in any gaps. To examine the relationship between cytokine storm and COVID-19 severity in patients, the Shapley additive explanation (SHAP) and the LIME (Local Interpretable Model-agnostic Explanations) model were applied. Individuals with severe SARS-CoV-2 infection had elevated plasma levels of VEGF-A, MIP-1b, and IL-17. RANTES and TNF were associated with healthy individuals, whereas IL-27, IL-9, IL-12p40, and MCP-3 were associated with non-Severity. These findings suggest that these cytokines may promote the development of novel preventive and therapeutic pathways for disease management. In this study, the use of artificial intelligence is intended to support clinical diagnoses of patients to determine how each cytokine may be responsible for the severity of COVID-19, which could lead to the identification of several cytokines that could aid in treatment decision-making and vaccine development.

A specific anti‐COVID‐19 BNT162b2 vaccine‐induced early innate immune signature positively correlates with the humoral protective response in healthy and multiple sclerosis vaccine recipients

Objectives

The very rapidly approved mRNA‐based vaccines against SARS‐CoV‐2 spike glycoprotein, including Pfizer‐BioNTech BNT162b2, are effective in protecting from severe coronavirus disease 2019 (COVID‐19) in immunocompetent population. However, establishing the duration and identifying correlates of vaccine‐induced protection will be crucial to optimise future immunisation strategies. Here, we studied in healthy vaccine recipients and people with multiple sclerosis (pwMS), undergoing different therapies, the regulation of innate immune response by mRNA vaccination in order to correlate it with the magnitude of vaccine‐induced protective humoral responses.

Methods

Healthy subjects (n = 20) and matched pwMS (n = 22) were longitudinally sampled before and after mRNA vaccination. Peripheral blood mononuclear cell (PBMC)‐associated type I and II interferon (IFN)‐inducible gene expression, serum innate cytokine/chemokine profile as well as binding and neutralising anti‐SARS‐COV‐2 antibodies (Abs) were measured.

Results

We identified an early immune module composed of the IFN‐inducible genes Mx1, OAS1 and IRF1, the serum cytokines IL‐15, IL‐6, TNF‐α and IFN‐γ and the chemokines IP‐10, MCP‐1 and MIG, induced 1 day post second and third BNT162b2 vaccine doses, strongly correlating with magnitude of humoral response to vaccination in healthy and MS vaccinees. Moreover, induction of the early immune module was dramatically affected in pwMS treated with fingolimod and ocrelizumab, both groups unable to induce a protective humoral response to COVID‐19 vaccine.

Conclusion

Overall, this study suggests that the vaccine‐induced early regulation of innate immunity is mediated by IFN signalling, impacts on the magnitude of adaptive responses and it might be indicative of vaccine‐induced humoral protection.

Using Real-Time PCR Fluorescence Reaction Values to Improve SARS-CoV-2 Virus Detection and Benefit Clinical Decision-Making

This study aimed to compare the SARS-CoV-2 nucleic acid detection results of the BD MAX™ System and other platforms to formulate an optimized laboratory verification process. The re-examination of 400 samples determined as positive by BD MAX™ indicated that the inconsistency rate between BD MAX™ and the other platforms was 65.8%; the inconsistency rate of single-gene-positive results was as high as 99.2%. A receiver operating characteristic curve was drawn for the relative light unit (RLU) values of samples positive for a single gene, and RLU 800 was used as the cutoff. After setting the retest standard as single-gene positive and RLU ≥ 800, the number of the 260 BD MAX™ single-gene positives that needed to be confirmed again was 36 (13.8%) and the number that could be directly reported as negative was 224 (86.2%). This verification process can shorten the reporting period and speed up the epidemic adjustment time and turnover rate of special wards, thereby improving SARS-CoV-2 detection efficiency and clinical decision-making.

Antagonisms of ASFV towards Host Defense Mechanisms: Knowledge Gaps in Viral Immune Evasion and Pathogenesis

African swine fever (ASF) causes high morbidity and mortality of both domestic pigs and wild boars and severely impacts the swine industry worldwide. ASF virus (ASFV), the etiologic agent of ASF epidemics, mainly infects myeloid cells in swine mononuclear phagocyte system (MPS), including blood-circulating monocytes, tissue-resident macrophages, and dendritic cells (DCs). Since their significant roles in bridging host innate and adaptive immunity, these cells provide ASFV with favorable targets to manipulate and block their antiviral activities, leading to immune escape and immunosuppression. To date, vaccines are still being regarded as the most promising measure to prevent and control ASF outbreaks. However, ASF vaccine development is delayed and limited by existing knowledge gaps in viral immune evasion, pathogenesis, etc. Recent studies have revealed that ASFV can employ diverse strategies to interrupt the host defense mechanisms via abundant self-encoded proteins. Thus, this review mainly focuses on the antagonisms of ASFV-encoded proteins towards IFN-I production, IFN-induced antiviral response, NLRP3 inflammasome activation, and GSDMD-mediated pyroptosis. Additionally, we also make a brief discussion concerning the potential challenges in future development of ASF vaccine.

Prognostic Value of Magnesium in COVID-19: Findings from the COMEPA Study

Magnesium (Mg) plays a key role in infections. However, its role in coronavirus disease 2019 (COVID-19) is still underexplored, particularly in long-term sequelae. The aim of the present study was to examine the prognostic value of serum Mg levels in older people affected by COVID-19. Patients were divided into those with serum Mg levels ≤1.96 vs. >1.96 mg/dL, according to the Youden index. A total of 260 participants (mean age 65 years, 53.8% males) had valid Mg measurements. Serum Mg had a good accuracy in predicting in-hospital mortality (area under the curve = 0.83; 95% CI: 0.74-0.91). Low serum Mg at admission significantly predicted in-hospital death (HR = 1.29; 95% CI: 1.03-2.68) after adjusting for several confounders. A value of Mg ≤ 1.96 mg/dL was associated with a longer mean length of stay compared to those with a serum Mg > 1.96 (15.2 vs. 12.7 days). Low serum Mg was associated with a higher incidence of long COVID symptomatology (OR = 2.14; 95% CI: 1.30-4.31), particularly post-traumatic stress disorder (OR = 2.00; 95% CI: 1.24-16.40). In conclusion, low serum Mg levels were significant predictors of mortality, length of stay, and onset of long COVID symptoms, indicating that measuring serum Mg in COVID-19 may be helpful in the prediction of complications related to the disease.

The Influence of Comorbidities on Chemokine and Cytokine Profile in Obstructive Sleep Apnea Patients: Preliminary Results

INTRODUCTION

Obstructive sleep apnea (OSA) is frequently associated with a chronic inflammatory state and cardiovascular/metabolic complications. The aim of this study was to evaluate the influence of certain comorbidities on a panel of 45 chemokines and cytokines in OSA patients with special regard to their possible association with cardiovascular diseases.

MATERIAL AND METHODS

This cross-sectional study was performed on 61 newly diagnosed OSA patients. For the measurement of the plasma concentration of chemokines and cytokines, the magnetic bead-based multiplex assay for the Luminex^® platform was used.

RESULTS

In the patients with concomitant COPD, there were increased levels of pro-inflammatory cytokines (CCL11, CD-40 ligand) and decreased anti-inflammatory cytokine (IL-10), while in diabetes, there were increased levels of pro-inflammatory cytokines (IL-6, TRIAL). Obesity was associated with increased levels of both pro-inflammatory (IL-13) and anti-inflammatory (IL-1RA) cytokines. Hypertension was associated with increased levels of both pro-inflammatory (CCL3) and anti-inflammatory (IL-10) cytokines. Increased daytime pCO₂, low mean nocturnal SaO₂, and the oxygen desaturation index were associated with increased levels of pro-inflammatory cytokines (CXCL1, PDGF-AB, TNF-α, and IL-15).

CONCLUSIONS

In OSA patients with concomitant diabetes and COPD, elevated levels of certain pro-inflammatory and decreased levels of certain anti-inflammatory cytokines may favor the persistence of a chronic inflammatory state with further consequences. Nocturnal hypoxemia, frequent episodes of desaturation, and increased daytime pCO₂ are factors contributing to the chronic inflammatory state in OSA patients.

COVID-19 Heart Lesions in Children: Clinical, Diagnostic and Immunological Changes

In the beginning of COVID-19, the proportion of confirmed cases in the pediatric population was relatively small and there was an opinion that children often had a mild or asymptomatic course of infection. Our understanding of the immune response, diagnosis and treatment of COVID-19 is highly oriented towards the adult population. At the same time, despite the fact that COVID-19 in children usually occurs in a mild form, there is an incomplete understanding of the course as an acute infection and its subsequent manifestations such as Long-COVID-19 or Post-COVID-19, PASC in the pediatric population, correlations with comorbidities and immunological changes. In mild COVID-19 in childhood, some authors explain the absence of population decreasing T and B lymphocytes. Regardless of the patient's condition, they can have the second phase, related to the exacerbation of inflammation in the heart tissue even if the viral infection was completely eliminated-post infectious myocarditis. Mechanism of myocardial dysfunction development in MIS-C are not fully understood. It is known that various immunocompetent cells, including both resident inflammatory cells of peripheral tissues (for example macrophages, dendritic cells, resident memory T-lymphocytes and so on) and also circulating in the peripheral blood immune cells play an important role in the immunopathogenesis of myocarditis. It is expected that hyperproduction of interferons and the enhanced cytokine response of T cells 1 and 2 types contribute to dysfunction of the myocardium. However, the role of Th1 in the pathogenesis of myocarditis remains highly controversial. At the same time, the clinical manifestations and mechanisms of damage, including the heart, both against the background and after COVID-19, in children differ from adults. Further studies are needed to evaluate whether transient or persistent cardiac complications are associated with long-term adverse cardiac events.

Assessing Biomarkers in Viral Infection

Current biomarkers to assess the risk of complications of both acute and chronic viral infection are suboptimal. Prevalent viral infections like human immunodeficiency virus (HIV), hepatitis B and C virus, herpes viruses, and, more recently, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may be associated with significant sequelae including the risk of cardiovascular disease, other end-organ diseases, and malignancies. This review considers some biomarkers which have been investigated in diagnosis and prognosis of key viral infections including inflammatory cytokines, markers of endothelial dysfunction and activation and coagulation, and the role that more conventional diagnostic markers, such as C-reactive protein and procalcitonin, can play in predicting these secondary complications, as markers of severity and to distinguish viral and bacterial infection. Although many of these are still only available in the research setting, these markers show promise for incorporation in diagnostic algorithms which may assist to predict adverse outcomes and to guide therapy.

Cytokine Profiling in Different SARS-CoV-2 Genetic Variants

This study is a successor of our previous work concerning changes in the chemokine profile in infection that are associated with different SARS-CoV-2 genetic variants. The goal of our study was to take into account both the virus and the host immune system by assessing concentrations of cytokines in patients infected with different SARS-CoV-2 variants (ancestral Wuhan strain, Alpha, Delta and Omicron). Our study was performed on 340 biological samples taken from COVID-19 patients and healthy donors in the timespan between May 2020 and April 2022. We performed genotyping of the virus in nasopharyngeal swabs, which was followed by assessment of cytokines' concentration in blood plasma. We noted that out of nearly 30 cytokines, only four showed stable elevation independently of the variant (IL-6, IL-10, IL-18 and IL-27), and we believe them to be 'constant' markers for COVID-19 infection. Cytokines that were studied as potential biomarkers lose their diagnostic value as the virus evolves, and the specter of potential targets for predictive models is narrowing. So far, only four cytokines (IL-6, IL-10, IL-18, and IL-27) showed a consistent rise in concentrations independently of the genetic variant of the virus. Although we believe our findings to be of scientific interest, we still consider them inconclusive; further investigation and comparison of immune responses to different variants of SARS-CoV-2 is required.