COVID-19: the role of excessive cytokine release and potential ACE2 down-regulation in promoting hypercoagulable state associated with severe illness

Narrative Review Explaining the Role of HLA-A, -B, and -C Molecules in COVID-19 Disease in and around Africa

The coronavirus disease 2019 (COVID-19) has left a devasting effect on various regions globally. Africa has exceptionally high rates of other infectious diseases, such as tuberculosis (TB), human immunodeficiency virus (HIV), and malaria, and was not impacted by COVID-19 to the extent of other continents Globally, COVID-19 has caused approximately 7 million deaths and 700 million infections thus far. COVID-19 disease severity and susceptibility vary among individuals and populations, which could be attributed to various factors, including the viral strain, host genetics, environment, lifespan, and co-existing conditions. Host genetics play a substantial part in COVID-19 disease severity among individuals. Human leukocyte antigen (HLA) was previously been shown to be very important across host immune responses against viruses. HLA has been a widely studied gene region for various disease associations that have been identified. HLA proteins present peptides to the cytotoxic lymphocytes, which causes an immune response to kill infected cells. The HLA molecule serves as the central region for infectious disease association; therefore, we expect HLA disease association with COVID-19. Therefore, in this narrative review, we look at the HLA gene region, particularly, HLA class I, to understand its role in COVID-19 disease.

Modulations of Homeostatic ACE2, CD147, GRP78 Pathways Correlate with Vascular and Endothelial Performance Markers during Pulmonary SARS-CoV-2 Infection

The pathologic consequences of Coronavirus Disease-2019 (COVID-19) include elevated inflammation and dysregulated vascular functions associated with thrombosis. In general, disruption of vascular homeostasis and ensuing prothrombotic events are driven by activated platelets, monocytes, and macrophages, which form aggregates (thrombi) attached to the endothelium lining of vessel walls. However, molecular pathways underpinning the pathological interactions between myeloid cells and endothelium during COVID-19 remain undefined. Here, we tested the hypothesis that modulations in the expression of cellular receptors angiotensin-converting enzyme 2 (ACE2), CD147, and glucose-regulated protein 78 (GRP78), which are involved in homeostasis and endothelial performance, are the hallmark responses induced by SARS-CoV-2 infection. Cultured macrophages and lungs of hamster model systems were used to test this hypothesis. The results indicate that while macrophages and endothelial cells are less likely to support SARS-CoV-2 proliferation, these cells may readily respond to inflammatory stimuli generated by the infected lung epithelium. SARS-CoV-2 induced modulations of tested cellular receptors correlated with corresponding changes in the mRNA expression of coagulation cascade regulators and endothelial integrity components in infected hamster lungs. Among these markers, tissue factor (TF) had the best correlation for prothrombotic events during SARS-CoV-2 infection. Furthermore, the single-molecule fluorescence in situ hybridization (smFISH) method alone was sufficient to determine the peak and resolution phases of SARS-CoV-2 infection and enabled screening for cellular markers co-expressed with the virus. These findings suggest possible molecular pathways for exploration of novel drugs capable of blocking the prothrombotic shift events that exacerbate COVID-19 pathophysiology and control the disease.

Estimated plasma volume status in COVID-19 patients and its relation to comorbidities and clinical outcomes

Blood plasma is a large reservoir of circulating mediators of inflammation and its expansion has been associated with unfavorable outcomes in patients with inflammatory and cardiovascular diseases. The aim of this study was to determine clinical and prognostic value of estimated plasma volume status (ePVS) in hospitalized patients with COVID-19. We retrospectively investigated 5871 consecutive COVID-19 patient hospitalized in our tertiary-level institution in period 3/2020-6/2021. ePVS was determined using the Strauss-derived Duarte formula and was correlated with clinical characteristics and unwanted outcomes. Median ePVS was 4.77 dl/g with interquartile range 4.11-5.74. Higher ePVS was significantly associated with older age, female sex, higher comorbidity burden, worse functional status, less severe COVID-19 clinical presentation with lower severity and longer duration of symptoms, but more pronounced inflammatory profile with higher C-reactive protein, interleukin-6 and D-dimer levels (P < 0.05 for all analyses). In the multivariate regression analysis U shaped relationship of ePVS with mortality was revealed, present independently of age, sex, COVID-19 severity and comorbidity burden. In addition, higher ePVS was independently associated with higher tendency for mechanical ventilation, intensive care unit treatment, venous thromboembolism, major bleeding and bacteriemia and lower ePVS was independently associated with tendency for arterial thrombotic events. Higher ePVS, indicative of plasma volume expansion and inflammatory cytokine accumulation, may predispose respiratory deterioration and venous thromboembolism, despite less severe initial clinical presentation. Lower ePVS, indicative of hemoconcentration, may predispose arterial thrombotic events. Both may be associated with higher mortality in hospitalized COVID-19 patients.

Assessing the gene expression of the adenosine 5'-monophosphate-activated protein kinase (AMPK) and its relation with the IL-6 and IL-10 plasma levels in COVID-19 patients

BACKGROUND

Metabolic dysregulation and excessive inflammation are implicated in the pathogenesis of the highly infectious disease of coronavirus disease 2019 (COVID-19), which is caused by a newly emerging coronavirus (i.e., severe acute respiratory syndrome-coronavirus 2; SARS-CoV-2). The adenosine 5'-monophosphate-activated protein kinase (AMPK), an energy sensor regulating the metabolic pathways in diverse cells, exerts a regulatory role in the immune system. This study aims to examine the mRNA expression level of AMPK and the plasma levels of interleukin-6 (IL-6) and IL-10 cytokines in patients with different grades of COVID-19.

METHODS

Peripheral blood was collected from 60 patients with COVID-19 (Moderate, severe, and critical). The plasma levels of IL-6 and IL-10 were quantified by enzyme-linked immunosorbent assay (ELISA), and the mRNA expression level of AMPK was determined using real-time PCR.

RESULTS

The results showed that the plasma levels of IL-6 increased significantly in critical and severe patients compared to moderate cases of COVID-19 (P < 0.001). Moreover, IL-10 plasma concentrations were significantly higher in critical and severe cases than in moderate cases of COVID-19 (P < 0.01 and P < 0.05, respectively). Also, the gene expression of AMPK was meaningfully enhanced in critical patients relative to moderate and severe cases of COVID-19, in order (P < 0.001 and P < 0.01, respectively). There was a positive association between AMPK gene expression and plasma levels of IL-6 and IL-10 (P = 0.006, r = 0.348, P = 0.028, r = 0.283, respectively).

CONCLUSION

Increasing AMPK gene expression is likely a necessary effort of the immune system to inhibit inflammation in critical COVID-19. However, this effort seems to be inadequate, probably due to factors that induce inflammation, like erythrocyte sedimentation rate (ESR) and IL-6.

The use of Tocilizumab in COVID-19 critically ill patients with renal impairment: a multicenter, cohort study

Tocilizumab (TCZ) is recommended in patients with COVID-19 who require oxygen therapy or ventilatory support. Despite the wide use of TCZ, little is known about its safety and effectiveness in patients with COVID-19 and renal impairment. Therefore, this study evaluated the safety and effectiveness of TCZ in critically ill patients with COVID-19 and renal impairment. A multicenter retrospective cohort study included all adult COVID-19 patients with renal impairment (eGFR˂60 mL/min) admitted to the ICUs between March 2020 and July 2021. Patients were categorized into two groups based on TCZ use (Control vs. TCZ). The primary endpoint was the development of acute kidney injury (AKI) during ICU stay. We screened 1599 patients for eligibility; 394 patients were eligible, and 225 patients were included after PS matching (1:2 ratio); there were 75 TCZ-treated subjects and 150 controls. The rate of AKI was higher in the TCZ group compared with the control group (72.2% versus 57.4%; p = 0.03; OR: 1.83; 95% CI: 1.01, 3.34; p = 0.04). Additionally, the ICU length of stay was significantly longer in patients who received TCZ (17.5 days versus 12.5 days; p = 0.006, Beta coefficient: 0.30 days, 95% CI: 0.09, 0.50; p = 0.005). On the other hand, the 30-day and in-hospital mortality were lower in patients who received TCZ compared to the control group (HR: 0.45, 95% CI: 0.27, 0.73; p = 0.01 and HR: 0.63, 95% CI: 0.41, 0.96; p = 0.03, respectively). The use of TCZ in this population was associated with a statistically significantly higher rate of AKI while improving the overall survival on the other hand. Further research is needed to assess the risks and benefits of TCZ treatment in critically ill COVID-19 patients with renal impairment.

Targeting IL-6 trans-signalling: past, present and future prospects

Interleukin-6 (IL-6) is a key immunomodulatory cytokine that affects the pathogenesis of diverse diseases, including autoimmune diseases, chronic inflammatory conditions and cancer. Classical IL-6 signalling involves the binding of IL-6 to the membrane-bound IL-6 receptor α-subunit (hereafter termed 'mIL-6R') and glycoprotein 130 (gp130) signal-transducing subunit. By contrast, in IL-6 trans-signalling, complexes of IL-6 and the soluble form of IL-6 receptor (sIL-6R) signal via membrane-bound gp130. A third mode of IL-6 signalling - known as cluster signalling - involves preformed complexes of membrane-bound IL-6-mIL-6R on one cell activating gp130 subunits on target cells. Antibodies and small molecules have been developed that block all three forms of IL-6 signalling, but in the past decade, IL-6 trans-signalling has emerged as the predominant pathway by which IL-6 promotes disease pathogenesis. The first selective inhibitor of IL-6 trans-signalling, sgp130, has shown therapeutic potential in various preclinical models of disease and olamkicept, a sgp130Fc variant, had promising results in phase II clinical studies for inflammatory bowel disease. Technological developments have already led to next-generation sgp130 variants with increased affinity and selectivity towards IL-6 trans-signalling, along with indirect strategies to block IL-6 trans-signalling. Here, we summarize our current understanding of the biological outcomes of IL-6-mediated signalling and the potential for targeting this pathway in the clinic.

Early treatment with low-molecular-weight heparin reduces mortality rate in SARS-CoV-2 patients

BACKGROUND

Since the beginning of the SARS-CoV-2 pandemic, millions of people have been infected and died. Different therapeutic approaches have been recommended, but only a few have shown clinical advantages. Low-molecular-weight heparin (LMWH) has been recommended to prevent COVID-19-related thrombo-embolic events. We aimed to evaluate the impact of early treatment with LMWH on hospital admission and death in patients with SARS-CoV-2 infection.

METHODS

We conducted an observational monocentric retrospective study to evaluate the preventive role of LMWH on the mortality rate of COVID-19 patients. SARS-CoV-2 infected patients were recruited from the beginning of the Italian epidemic to March 31, 2021. We excluded patients with missing data and those chronically exposed to LMWH. Treatment prescription was based on international and national guidelines and modified depending on clinical presentation and drug-drug interactions.

RESULTS

Seven hundred thirty-four SARS-CoV-2 infected patients were recruited, with 357 (48.6%) males and a median (IQR) age of 77.9 (65-85.7) years. 77.5% of people developed SARS-CoV-2-related symptoms and 62.8% were admitted to the hospital, and 20.2% died. Four hundred ninety-two (67%) started LMWH. In particular, 296 (40.3%) were treated within five days since symptoms onset. At logistic regression, early LMWH therapy was associated with lower mortality. Furthermore, remdesivir treatment showed a lower risk of death. On the contrary, age, BMI>30 kg/m2, neurological diseases, fever or dyspnea were associated with an increased risk of death.

CONCLUSIONS

Early treatment with LMWH was associated with lower mortality in our cohort. Further studies are needed to better assess the role of wider LMWH administration in terms of timing and regimen dose.

Unraveling Acute and Post-COVID Cytokine Patterns to Anticipate Future Challenges

The aims of this study were to analyze cytokine profiles in patients with COVID-19, gain insights into the immune response during acute infection, identify cytokines associated with disease severity and post-COVID complications, and explore potential biomarkers for prognosis and therapeutic targets. Using a multiplex analysis, we studied the cytokine pattern in 294 acute COVID-19 and post-COVID patients with varying severities of infection. Our findings revealed that disease severity was associated with elevated levels of IL-15, IL-8, and fractalkine. Severe/extremely severe forms in comparison with mild/moderate disease were associated with MCP-1, IFNa2, IL-7, IL-15, EGF, IP-10, IL-8, Eotaxin, FGF-2, GROa, sCD40L, and IL-10. The key cytokines of post-COVID are FGF-2, VEGF-A, EGF, IL-12(p70), IL-13, and IL-6. By the sixth month after recovering from a coronavirus infection, regardless of disease severity, some patients may develop complications such as arterial hypertension, type 2 diabetes mellitus, glucose intolerance, thyrotoxicosis, atherosclerosis, and rapid progression of previously diagnosed conditions. Each complication is characterized by distinct cytokine profiles. Importantly, these complications can also be predicted during the acute phase of the coronavirus infection. Understanding cytokine patterns can aid in predicting disease progression, identifying high-risk patients, and developing targeted interventions to improve the outcomes of COVID-19.

Impact of the Angiotensin-Converting Enzyme (ACE) Inhibitors on the Course of the Acute Respiratory Distress Syndrome (ARDS) Developed During COVID-19 and Other Severe Respiratory Infections Under Hyperferritinemia Conditions: A Cohort Study

Background

Angiotensin-converting enzyme 2 (ACE2) is not only the entry route of SARS-CoV-2 infection but also triggers a major mechanism of COVID-19 aggravation by promoting a hyperinflammatory state, leading to lung injury, hematological and immunological dysregulation. The impact of ACE2 inhibitors on the course of COVID-19 is still unclear. The effect of ACE2 inhibitors on the course of acute respiratory distress syndrome (ARDS) during COVID-19 and other severe respiratory infections in conditions of hyperferritinemia (HF) was investigated.

Methods

A cohort study of critically ill patients with COVID-19 and other respiratory diseases (widespread infection, pneumonia) who underwent treatment in The Critical Care Unit of the First University Clinic (Tbilisi, Georgia) during the 2020-2021 years was conducted. The impact of the ACE2 inhibitors on the course of the ARDS developed during COVID-19 and other severe respiratory infections in conditions of different severity of HF was evaluated.

Results

In COVID-19-infected (I) and uninfected (II) patients with ARDS, ACE2 inhibitors reduce the levels of Ang II, C reactive protein (CRP) and D-dimer (I: from 1508.07  ±  26.68 to 48.51  ±  24.35, from 233.92  ±  13.02 to 198.12  ±  11.88, from 7.88  ±  0.47 to 6.28  ±  0.43; II: from 1000.14  ±  149.49 to 46.23  ±  88.21, 226.48  ±  13.81 to 183.52  ±  17.32, from 6.39  ±  0.58 to 5.48  ±  0.69) at moderate HF and Ang II, CRP levels (I: from 1845.89  ±  89.37 to 49.64  ±  51.05, from 209.28  ±  14.41 to 175.37  ±  9.84; II: from 1753.29  ±  65.95 to 49.76  ±  55.74, 287.10  ±  20.50 to 214.71  ±  17.32) at severe HF, reduce interleukin-6 (IL-6) expression at moderate HF (I: from 1977.23  ±  354.66 to 899.36  ±  323.76) and cause reduction of pCO2 index at severe HF (I: from 69.80  ±  3.22 to 60.44  ±  2.20) in COVID-19-infected patients.

Conclusion

Study results show that the ACE2 inhibitors play an important role in the regulation of inflammatory processes in both COVID-19-infected and uninfected patients with ARDS. ACE2 inhibitors decrease immunological disorders, inflammation, and lung alveoli dysfunction, especially in COVID-19-infected patients.

The controversial effect of smoking and nicotine in SARS-CoV-2 infection

The effects of nicotine and cigarette smoke in many diseases, notably COVID-19 infection, are being debated more frequently. The current basic data for COVID-19 is increasing and indicating the higher risk of COVID-19 infections in smokers due to the overexpression of corresponding host receptors to viral entry. However, current multi-national epidemiological reports indicate a lower incidence of COVID-19 disease in smokers. Current data indicates that smokers are more susceptible to some diseases and more protective of some other. Interestingly, nicotine is also reported to play a dual role, being both inflammatory and anti-inflammatory. In the present study, we tried to investigate the effect of pure nicotine on various cells involved in COVID-19 infection. We followed an organ-based systematic approach to decipher the effect of nicotine in damaged organs corresponding to COVID-19 pathogenesis (12 related diseases). Considering that the effects of nicotine and cigarette smoke are different from each other, it is necessary to be careful in generalizing the effects of nicotine and cigarette to each other in the conducted researches. The generalization and the undifferentiation of nicotine from smoke is a significant bias. Moreover, different doses of nicotine stimulate different effects (dose-dependent response). In addition to further assessing the role of nicotine in COVID-19 infection and any other cases, a clever assessment of underlying diseases should also be considered to achieve a guideline for health providers and a personalized approach to treatment.

Potential Benefits of Omega-3 Polyunsaturated Fatty Acids (N3PUFAs) on Cardiovascular Health Associated with COVID-19: An Update for 2023

The accumulating literature demonstrates that omega-3 polyunsaturated fatty acid (n-3 polyunsaturated fatty acid, N3PUFA) can be incorporated into the phospholipid bilayer of cell membranes in the human body to positively affect the cardiovascular system, including improving epithelial function, decreasing coagulopathy, and attenuating uncontrolled inflammatory responses and oxidative stress. Moreover, it has been proven that the N3PUFAs, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are precursors of some potent endogenous bioactive lipid mediators that mediate some favorable effects attributed to their parent substances. A dose-response relationship between increased EPA and DHA intake and reduced thrombotic outcomes has been reported. The excellent safety profile of dietary N3PUFAs makes them a prospective adjuvant treatment for people exposed to a higher risk of cardiovascular problems associated with COVID-19. This review presented the potential mechanisms that might contribute to the beneficial effects of N3PUFA and the optimal form and dose applied.

Neutrophil activation and neutrophil extracellular traps (NETs) in COVID-19 ARDS and immunothrombosis

Acute respiratory distress syndrome (ARDS) is an acute inflammatory condition with a dramatic increase in incidence since the beginning of the coronavirus disease 19 (COVID-19) pandemic. Neutrophils play a vital role in the immunopathology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by triggering the formation of neutrophil extracellular traps (NETs), producing cytokines including interleukin-8 (CXCL8), and mediating the recruitment of other immune cells to regulate processes such as acute and chronic inflammation, which can lead to ARDS. CXCL8 is involved in the recruitment, activation, and degranulation of neutrophils, and therefore contributes to inflammation amplification and severity of disease. Furthermore, activation of neutrophils also supports a prothrombotic phenotype, which may explain the development of immunothrombosis observed in COVID-19 ARDS. This review aims to describe hyperinflammatory ARDS due to SARS-CoV-2 infection. In addition, we address the critical role of polymorphonuclear neutrophils, inflammatory cytokines, and the potential targeting of CXCL8 in treating the hyperinflammatory ARDS population.

Interleukin 6: A biomarker for COVID-19 progression

COVID-19 was discovered in China for the first time in December 2019 and was declared a pandemic by the World Health Organization on March 11, 2020. Due to its rapid geographic expansion over the last three years, it has now become a global health issue. The infection is caused by SARS-CoV-2, which is obtained from a zoonotic source and transmitted directly or through contact. Following exposure, the immune system becomes hyperactive resulting in the production of pro-inflammatory cytokines, particularly interleukin-6 (IL-6), a naturally occurring pleiotropic cytokine that plays a significant role in respiratory failure and multi-organ dysfunction. This massive inflammatory phenomenon is reminiscent of cytokine release syndrome (CRS) or "cytokine storm", which may be at the root of many severe complications. In fact, serum IL-6 levels are significantly high in patients with severe Covid-19 disease. The goal of treatment is to change the cytokine's concentration or activity. Interleukin-6 production could be inhibited, reducing inflammation and so serving as a therapeutic target. anti-interleukin-6 receptor monoclonal antibodies have been proven to reduce the severity of COVID-19 in clinical trials aimed at clarifying the function of immunoregulation. As a result, the Il-6 assay is a reliable predictor of morbidity and mortality at the time of infection diagnosis. The aim of our study is to highlight the role of interleukin 6 as biomarker of the COVID- 19 progression.

Potential long-term effects of SARS-CoV-2 infection on the pulmonary vasculature: Multilayered cross-talks in the setting of coinfections and comorbidities

The Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and its sublineages pose a new challenge to healthcare systems worldwide due to its ability to efficiently spread in immunized populations and its resistance to currently available therapies. COVID-19, although targeting primarily the respiratory system, is also now well established that later affects every organ in the body. Most importantly, despite the available therapy and vaccine-elicited protection, the long-term consequences of viral infection in breakthrough and asymptomatic individuals are areas of concern. In the past two years, investigators accumulated evidence on how the virus triggers our immune system and the molecular signals involved in the cross-talk between immune cells and structural cells in the pulmonary vasculature to drive pathological lung complications such as endothelial dysfunction and thrombosis. In the review, we emphasize recent updates on the pathophysiological inflammatory and immune responses associated with SARS-CoV-2 infection and their potential long-term consequences that may consequently lead to the development of pulmonary vascular diseases.

The suboptimal fibrinolytic response in COVID-19 is dictated by high PAI-1

BACKGROUND

Severe COVID-19 disease is associated with thrombotic complications and extensive fibrin deposition. This study investigates whether the hemostatic complications in COVID-19 disease arise due to dysregulation of the fibrinolytic system.

METHODS

This prospective study analyzed fibrinolytic profiles of 113 patients hospitalized with COVID-19 disease with 24 patients with non-COVID-19 respiratory infection and healthy controls. Antigens were quantified by Ella system or ELISA, clot lysis by turbidimetric assay, and plasminogen activator inhibitor-1 (PAI-1)/plasmin activity using chromogenic substrates. Clot structure was visualized by confocal microscopy.

RESULTS

PAI-1 and its cofactor, vitronectin, are significantly elevated in patients with COVID-19 disease compared with those with non-COVID-19 respiratory infection and healthy control groups. Thrombin activatable fibrinolysis inhibitor and tissue plasminogen activator were elevated in patients with COVID-19 disease relative to healthy controls. PAI-1 and tissue plasminogen activator (tPA) were associated with more severe COVID-19 disease severity. Clots formed from COVID-19 plasma demonstrate an altered fibrin network, with attenuated fiber length and increased branching. Functional studies reveal that plasmin generation and clot lysis were markedly attenuated in COVID-19 disease, while PAI-1 activity was elevated. Clot lysis time significantly correlated with PAI-1 levels. Stratification of COVID-19 samples according to PAI-1 levels reveals significantly faster lysis when using the PAI-1 resistant (tPA) variant, tenecteplase, over alteplase lysis.

CONCLUSION

This study shows that the suboptimal fibrinolytic response in COVID-19 disease is directly attributable to elevated levels of PAI-1, which attenuate plasmin generation. These data highlight the important prognostic potential of PAI-1 and the possibility of using pre-existing drugs, such as tenecteplase, to treat COVID-19 disease and potentially other respiratory diseases.

Aseptic osteonecrosis of the maxilla after severe COVID-19 infection and its treatment

The course of the new SARS-CoV-2 (COVID-19) is unpredictable and is still being investigated. Although the majority of complications are expected to affect the respiratory system, there have been reports in literature concerning the adverse effects of the infection on bone and joint tissue. Several complications have been observed in the maxillofacial area in people who suffered from the infection, including osteonecrosis and osteomyelitis of the jaw. These complications have been subject to various hypotheses. They may result either from the disease pathogenetic mechanism or from a response to the therapeutic modalities used to treat the underlying disease, and overuse of particular medications – glucocorticoids, antirheumatics, interleukin-6 inhibitors, and antibiotics. This article presents a case of osteonecrosis of the maxilla after severe COVID-19 infection.

Association between use of novel glucose-lowering drugs and COVID-19 hospitalization and death in patients with type 2 diabetes: a nationwide registry analysis

AIMS

Type 2 diabetes (T2DM) in patients with coronavirus disease-19 (COVID-19) is associated with a worse prognosis. We separately investigated the associations between the use of sodium-glucose cotransporter 2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1 RA), and dipeptidyl peptidase-4 inhibitors (DPP-4i), and the risk of COVID-19 hospitalization and death.

METHODS AND RESULTS

Patients with T2DM registered in the Swedish National Patient Registry and alive on 1 February 2020 were included. 'Incident severe COVID-19' was defined as the first hospitalization and/or death from COVID-19. A modified Poisson regression approach was applied to a 1:1 propensity score-matched population receiving vs. not receiving SGLT2i, GLP-1 RA, and DPP-4i to analyse the associations between their use and (I) incident severe COVID-19 and (II) risk of 30-day mortality in patients hospitalized for COVID-19.Among 344 413 patients, 39 172 (11%) were treated with SGLT2i, 34 290 (10%) with GLP-1 RA, and 53 044 (15%) with DPP-4i; 9538 (2.8%) had incident severe COVID-19 by 15 May 2021. SGLT2i and DPP-4i were associated with a 10% and 11% higher risk of incident severe COVID-19, respectively, whereas there was no association for GLP-1 RA. DPP-4i was also associated with a 10% higher 30-day mortality in patients hospitalized for COVID-19, whereas there was no association for SGLT2i and GLP-1 RA.

CONCLUSION

SGLT2i and DPP-4i use were associated with a higher risk of incident severe COVID-19. DPP-4i use was associated with higher 30-day mortality in patients with COVID-19, whereas SGLT2i use was not. No increased risk for any outcome was observed with GLP-1 RA.

Risk stratification and prognostic value of prothrombin time and activated partial thromboplastin time among COVID-19 patients

Background

COVID-19 is a viral disease caused by a new strain of corona virus. Currently, prognosis and risk stratification of COVID-19 patients is done by the disease’s clinical presentation. Therefore, identifying laboratory biomarkers for disease prognosis and risk stratification of COVID-19 patients is critical for prompt treatment. Therefore, the main objective of this study was to assess the risk stratification and prognostic value of basic coagulation parameters and factors associated with disease severity among COVID-19 patients at the Tibebe Ghion Specialized Hospital, COVID-19 treatment center, Northwest Ethiopia.

Methods

A follow-up study was conducted among conveniently recruited COVID-19 patients attended from March to June 2021. Socio-demographic and clinical data were collected using a structured questionnaire and checklist, respectively. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were analyzed by the HUMACLOT DUE PLUS^® machine. Descriptive statistics were used to summarize the socio-demographic and clinical characteristics of study participants. Kruskal Wallis tests were used to compare the difference between parametric and non-parametric continuous variables, respectively. The area under the receiver operating characteristic curve (AUC) was used to evaluate the value of PT and APTT in the risk stratification and disease prognosis of COVID-19 patients. Ordinal logistic regression was used to identify the factors associated with disease severity and prognosis. A P-value < 0.05 was defined as statistically significant for all results.

Result

Baseline PT at a cut-off value ≥ 16.25 seconds differentiated severe COVID-19 patients from mild and moderate patients (AUC: 0.89, 95% CI: 0.83–0.95). PT also differentiated mild COVID-19 patients from moderate and severe patients at a cut-off value ≤ 15.35 seconds (AUC: 0.90, 95% CI: 0.84–0.96). Moreover, alcohol drinkers were a 3.52 times more likely chance of having severe disease than non-drinkers (95% CI: 1.41–8.81). A one-year increment in age also increased the odds of disease severity by 6% (95% CI: 3–9%). An increment of ≥ 0.65 seconds from the baseline PT predicted poor prognosis (AUC: 0.93, 0.87–0.99).

Conclusions and recommendations

Prolonged baseline PT was observed in severe COVID-19 patients. Prolonged baseline PT was also predicted to worsen prognosis. An increase from the baseline PT was associated with worsen prognosis. Therefore, PT can be used as a risk stratification and prognostic marker in COVID-19 patients.

Renin-angiotensin system modulation and outcomes in patients hospitalized for interstitial SARS-CoV2 pneumonia: a cohort study

AIM

The role of cardiovascular (CV) pharmacotherapies in patients with severe COVID-19 pneumonia remains controversial. This study aims to assess the impact of renin-angiotensin system modulation (RASi) (either angiotensin-converting enzymes (ACEIs) or angiotensin-receptor blockers (ARBs)) on COVID-19 outcome.

METHODS

We performed a cohort study on consecutive patients admitted for COVID-19 pneumonia at the Internal Medicine Unit of Sant'Orsola-Malpighi Hospital in Bologna, Italy. Patients with a possible alternative cause of respiratory failure other than COVID-19 were excluded. Clinical, pharmacological and laboratory data at admission and during the hospitalization were collected. Patients were treated with intravenous dexamethasone, low molecular weight heparin and nasal flow or Venturi mask oxygen. Subjects were followed until discharge, Intensive Care Unit (ICU) admission or death. Severe cases were defined by acute respiratory distress syndrome (arterial oxygen partial pressure and the fraction of inhaled oxygen ratio (P/F) ≤ 100 mmHg/%, or P/F ≤ 150 mmHg/% and respiratory rate ≥ 26/min). Patients with chronic use of RAS modulation were compared with those without for the composite outcome of in-hospital mortality or ICU admission. Hazard ratios (HR) were obtained by Cox regression, adjusted for several clinical factors.

RESULTS

Of the 268 patients enrolled in the study, 93 (35%, mean age 68 ± 13 years, 67% males) were treated with RASi (58% ACEIs and 42% ARBs). There were no meaningful differences between the RASI and no RASI group regarding clinical and laboratory parameters at admission. As expected, patients in the RASi group had a higher prevalence of hypertension, diabetes mellitus, atrial fibrillation, and ischemic heart disease. One hundred eight patients (40%) were admitted to ICU during hospitalization due to severe respiratory failure, and 24 (9%) died. The risk of in-hospital death or ICU admission was lower in the RASI group than in the non-RASI group (age and sex-adjusted HR 0.57, 95% CI 0.37-0.8), even after adjustment for several comorbidities (fully adjusted HR 0.44, 95% CI 0.26-0.74). Seven (7.5%) patients died in the RASi group vs 17 (9.7%) in the non-RASi group, leading to a non-statistically significant mortality risk reduction (fully adjusted HR 0.69, 95% CI 0.18-1.90). The lower risk in the RASi group was primarily related to ARBs use compared to ACEIs (HR 0.5, 95% CI 0.28-0.92 and HR 0.82, 95% CI 0.51-1.32, respectively).

CONCLUSIONS

Our study showed an inverse association between the chronic use of RASi and COVID-19 pneumonia severity (either ICU admissions or in-hospital death), even when significant comorbidities are considered.

Immune Targeted Therapies for COVID-19 Infection: A Narrative Review

In December 2019, the coronavirus disease-2019 (COVID-19) outbreak emerged in Wuhan, China. The World Health Organization officially declared it a pandemic on March 11, 2020. Reports indicated that the associated mortality of the infection is quite higher in the elderly, individuals with specific comorbidities (such as diabetes mellitus), and generally the ones with a compromised immune system. A cohort study in Wuhan, China, reported a dysregulated immune response in 452 patients with laboratory-confirmed COVID-19. As a result of this suppressed immune response, an increase in neutrophil to lymphocyte ratio, T lymphopenia, and a decrease in CD4⁺ T cells were all common laboratory findings, especially in severe cases. On the other hand, there is substantial evidence of T cell exhaustion in critically ill patients. Accordingly, the immune system seems to play an important role in the prognosis and pathogenesis of the disease. Therefore, this study aims to review the evidence on the immune response dysregulation in COVID-19 infection and the potential role of immunoregulatory treatments such as immune checkpoint inhibitors, interferons, and CD200 inhibitors in altering disease prognosis, especially in critically ill patients.

Tangled quest of post-COVID-19 infection-caused neuropathology and what 3P nano-bio-medicine can solve?

COVID-19-caused neurological problems are the important post-CoV-2 infection complications, which are recorded in ~ 40% of critically ill COVID-19 patients. Neurodegeneration (ND) is one of the most serious complications. It is necessary to understand its molecular mechanism(s), define research gaps to direct research to, hopefully, design new treatment modalities, for predictive diagnosis, patient stratification, targeted prevention, prognostic assessment, and personalized medical services for this type of complication. Individualized nano-bio-medicine combines nano-medicine (NM) with clinical and molecular biomarkers based on omics data to improve during- and post-illness management or post-infection prognosis, in addition to personalized dosage profiling and drug selection for maximum treatment efficacy, safety with least side-effects. This review will enumerate proteins, receptors, and enzymes involved in CoV-2 entrance into the central nervous system (CNS) via the blood–brain barrier (BBB), and list the repercussions after that entry, ranging from neuroinflammation to neurological symptoms disruption mechanism. Moreover, molecular mechanisms that mediate the host effect or viral detrimental effect on the host are discussed here, including autophagy, non-coding RNAs, inflammasome, and other molecular mechanisms of CoV-2 infection neuro-affection that are defined here as hallmarks of neuropathology related to COVID-19 infection. Thus, a couple of questions are raised; for example, “What are the hallmarks of neurodegeneration during COVID-19 infection?” and “Are epigenetics promising solution against post-COVID-19 neurodegeneration?” In addition, nano-formulas might be a better novel treatment for COVID-19 neurological complications, which raises one more question, “What are the challenges of nano-bio-based nanocarriers pre- or post-COVID-19 infection?” especially in the light of omics-based changes/challenges, research, and clinical practice in the framework of predictive preventive personalized medicine (PPPM / 3P medicine).

Analgesics Induce Alterations in the Expression of SARS-CoV-2 Entry and Arachidonic-Acid-Metabolizing Genes in the Mouse Lungs

Paracetamol and nonsteroidal anti-inflammatory drugs are widely used in the management of respiratory viral infections. This study aimed to determine the effects of the most commonly used analgesics (paracetamol, ibuprofen, and diclofenac) on the mRNA expression of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry and arachidonic-acid-metabolizing genes in mouse lungs. A total of twenty eight Balb/c mice were divided into four groups and treated separately with vehicle, paracetamol, ibuprofen, and diclofenac in clinically equivalent doses for 14 days. Then, the expressions of SARS-CoV-2 entry, ACE2, TMPRSS2, and Ctsl genes, in addition to the arachidonic-acid-metabolizing cyp450, cox, and alox genes, were analyzed using real-time PCR. Paracetamol increased the expressions of TMPRSS2 and Ctsl genes by 8.5 and 5.6 folds, respectively, while ibuprofen and diclofenac significantly decreased the expression of the ACE2 gene by more than 2.5 folds. In addition, all tested drugs downregulated (p < 0.05) cox2 gene expression, and paracetamol reduced the mRNA levels of cyp4a12 and 2j5. These molecular alterations in diclofenac and ibuprofen were associated with pathohistological alterations, where both analgesics induced the infiltration of inflammatory cells and airway wall thickening. It is concluded that analgesics such as paracetamol, ibuprofen, and diclofenac alter the expression of SARS-CoV-2 entry and arachidonic-acid-metabolizing genes in mouse lungs.

Platelet Distribution Width and Increased D-Dimer at Admission Predicts Subsequent Development of ARDS in COVID-19 Patients

In the current pandemic of coronavirus disease (COVID-19), the identification of the patients admitted with severe infection–who are disposed to a high risk of acute respiratory distress syndrome (ARDS) development, is of a major significance for the determination of the appropriate therapeutic strategy. Laboratory records in admission were retrospectively reviewed from 493 cases of severe COVID-19 divided into two groups: Group 1 with ARDS and Group 2 without ARDS. The platelet distribution width (PDW) difference between Group 1 and Group 2 is significant–15.10 ± 2.08 fl for those who developed ARDS versus 12.94 ± 2.12 fl for those without ARDS. The sensitivity and the specificity of this parameter is lower than that of D-dimer. After grouping of the PDW values into intervals and combining them with the rate of increase in D-dimer (D-PDWf index) to form a forecasting index, a significant increase in the specificity and sensitivity of the two parameters is identified–area under the ROC curve (AUC) is 0.874 for D-PDWf index, with respective AUC for PDW 0.768 and AUC for D-dimer 0.777. Conclusion: PDW is a significant predictive parameter at admission for subsequent development of ARDS in patients, with increased significance in combination with the degree of increase in D-dimer.

Possible Role of Matrix Metalloproteinases and TGF-β in COVID-19 Severity and Sequelae

The costs of coronavirus disease 2019 (COVID-19) are devastating. With millions of deaths worldwide, specific serological biomarkers, antiviral agents, and novel therapies are urgently required to reduce the disease burden. For these purposes, a profound understanding of the pathobiology of COVID-19 is mandatory. Notably, the study of immunity against other respiratory infections has generated reference knowledge to comprehend the paradox of the COVID-19 pathogenesis. Past studies point to a complex interplay between cytokines and other factors mediating wound healing and extracellular matrix (ECM) remodeling that results in exacerbated inflammation, tissue injury, severe manifestations, and a sequela of respiratory infections. This review provides an overview of the immunological process elicited after severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Also, we analyzed available data about the participation of matrix metalloproteinases (MMPs) and transforming growth factor-beta (TGF-β) in immune responses of the lungs. Furthermore, we discuss their possible implications in severe COVID-19 and sequela, including pulmonary fibrosis, and remark on the potential of these molecules as biomarkers for diagnosis, prognosis, and treatment of convalescent COVID-19 patients. Our review provides a theoretical framework for future research aimed to discover molecular hallmarks that, combined with clinical features, could serve as therapeutic targets and reliable biomarkers of the different clinical forms of COVID-19, including convalescence.

Debulking SARS-CoV-2 in saliva using angiotensin converting enzyme 2 in chewing gum to decrease oral virus transmission and infection

To advance a novel concept of debulking virus in the oral cavity, the primary site of viral replication, virus-trapping proteins CTB-ACE2 were expressed in chloroplasts and clinical-grade plant material was developed to meet FDA requirements. Chewing gum (2 g) containing plant cells expressed CTB-ACE2 up to 17.2 mg ACE2/g dry weight (11.7% leaf protein), have physical characteristics and taste/flavor like conventional gums, and no protein was lost during gum compression. CTB-ACE2 gum efficiently (>95%) inhibited entry of lentivirus spike or VSV-spike pseudovirus into Vero/CHO cells when quantified by luciferase or red fluorescence. Incubation of CTB-ACE2 microparticles reduced SARS-CoV-2 virus count in COVID-19 swab/saliva samples by >95% when evaluated by microbubbles (femtomolar concentration) or qPCR, demonstrating both virus trapping and blocking of cellular entry. COVID-19 saliva samples showed low or undetectable ACE2 activity when compared with healthy individuals (2,582 versus 50,126 ΔRFU; 27 versus 225 enzyme units), confirming greater susceptibility of infected patients for viral entry. CTB-ACE2 activity was completely inhibited by pre-incubation with SARS-CoV-2 receptor-binding domain, offering an explanation for reduced saliva ACE2 activity among COVID-19 patients. Chewing gum with virus-trapping proteins offers a general affordable strategy to protect patients from most oral virus re-infections through debulking or minimizing transmission to others.

Evaluation of the relationship between IL-6 gene single nucleotide polymorphisms and the severity of COVID-19 in an Iranian population

Background

Emerged coronavirus disease 2019 (COVID-19) is a pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2). Disease severity is associated with elevated levels of proinflammatory cytokines, such as interleukin-6 (IL-6). Genetic polymorphisms in the regulatory regions of cytokine genes may be associated with differential cytokine production in COVID-19 patients. This study aimed to investigate the association between three potentially functional single-nucleotide polymorphisms (SNPs) in the promoter region of IL-6 and the severity of susceptibility to COVID-19 in an Iranian population.

Methods

In total, 346 individuals (175 patients with severe COVID-19 and 171 patients with mild COVID-19) were recruited for this cohort study. Genomic DNA was extracted from peripheral blood leukocytes of patients to determine the genotypes of three selected SNPs (rs1800795 (−174 G > C), rs1800796 (−572 G > C), and rs1800797 (−597 G > A)) in the promoter region of the IL-6 gene using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method.

Results

There were no significant differences in the genotype or allele distribution of selected SNPs (rs1800795 (−174 G > C), rs1800796 (−572 G > C), and rs1800797 (−597 G > A)) in the promoter region of the IL-6 gene in patients with severe COVID-19 and patients with mild COVID-19.

Discussion

Our study indicated that these SNPs are not associated with COVID-19 severity in the Kurdish population from Kermanshah, Iran.

[Anticoagulation in coronavirus disease 2019 (COVID-19): confirmed and controversial aspects]

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is associated with a high risk of microvascular immunothrombosis as well as symptomatic and incidental thromboembolisms, predominantly in the venous system but also in the arterial system. This explains among other things the high cardiovascular morbidity and mortality of the patients. The present state of knowledge on the pathophysiology of immunothrombosis and the strategies of anticoagulation in patients with coronavirus disease 2019 (COVID-19) are summarized and illuminated in this article. According to the current guidelines moderately to severely ill patients who are being treated in hospital should receive thrombosis prophylaxis with low molecular weight or unfractionated heparin or alternatively with fondaparinux, as long as there is no clearly increased risk of bleeding. Apart from the established indications for treatment, an intensified or therapeutic dose prophylaxis should be considered very cautiously in these critically ill patients, also due to the increased bleeding complications. The routine continuation of prophylactic anticoagulation after discharge from hospital is currently not recommended.

Mitochondrial hijacking: A potential mechanism for SARS-CoV-2 to impair female fertility

As well as causing respiratory lesions, the multi-organ complications caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are also well known. Combined with the epidemiological characteristics of SARS-CoV-2 with high transmission rate and low lethality, the impact of complications caused by its infection on infected individuals seems to be of greater concern. There has been evidence that viral infection is complicated by female reproductive impairment, but the mechanism by which SARS-CoV-2 impairs female fertility is unclear. In addition, RNA-GPS technology has revealed that the SARS-CoV-2 genome resides in mitochondria of the host cells and affects mitochondrial function. Considering the close relationship between mitochondria and female fertility, this paper takes mitochondrial hijacking as an entry point to elucidate the possible mechanisms by which SARS-CoV-2 affects female fertility through the mitochondrial hijacking pathway, which will be important for timely preventive measures and identification of therapeutic targets for infected women with reproductive needs, especially those with asymptomatic infection.

Real world data on cardiometabolic diseases in U.S. adults during the SARS-CoV-2 pandemic: a decentralized registry study

Background

Pre-existing cardiometabolic comorbidities place SARS-CoV-2 positive patients at a greater risk for poorer clinical course and mortality than those without it. We aimed to analyze real-world registry data focused primarily on participants with cardiometabolic diseases (CMD), which were remotely obtained via a digital platform.

Methods

Participants were divided into two groups: CMD or no cardiometabolic disease (non-CMD). They were evaluated based on their medical history, current medications/supplements, COVID-19 status, demographics, and baseline characteristics. The frequency of medications/supplements for CMD were compared using relative risks and 95% confidence intervals. The WHO (Five) Well-Being Index (WHO-5) were collected monthly for 6 months to assess psychological well-being which included cheerfulness, calmness, vigor, rest, and engagement with daily activities of interest.

Results

The 791 enrollees represented 49 U.S. states. The CMD group had significantly higher (p < 0.0001) BMI (mean + 3.04 kg/m²) and age (mean + 9.15 years) compared to non-CMD group. In the CMD group, participants who tested positive for COVID-19 had lower (p < 0.0001) well-being scores than those without COVID-19. For the 274 participants on CMD medications/supplements, there was no statistical difference in risk of COVID-19 contracture based on medication/supplement type; however, all six participants who were not being treated for CMD were COVID-19 positive (RR ~ 104). For 89 participants who were on treatment for diabetes or insulin resistance, there was a 90% reduced risk of COVID-19 incidence (p = 0.0187).

Conclusion

The well-being score of the CMD group was dependent on whether they tested positive for COVID-19. Type of CMD treatment did not impact COVID-19 status, but absence of treatment significantly increased COVID-19 incidence. With respect to SARS-CoV-2, our analysis supports continued use of the statins, ACE-I, ARBs, and diabetes medications in CMD patients.

Trial registration: ClinicalTrials.gov Identifier: NCT04348942.

COVID-19 and dengue infection in Bangladesh: A case of coinfection where hemoptysis as first presentation

Bangladesh recently faced large outbreaks of both COVID-19 and dengue. We present a case of COVID-19 and dengue coinfection in a patient who presented with hemoptysis. Our results demonstrate that COVID-19 and dengue fever are both public health issues in Bangladesh and other dengue-endemic nations and that they can coexist.

Are platelet volume indices of clinical use in COVID-19? A systematic review

Background

The incidence of thrombotic complications is high in COVID-19 patients with severe disease. As key regulators of thrombus formation, platelets likely play a crucial role as mediators of severe acute respiratory syndrome coronavirus 2 associated pathogenesis. Studies have reported that parameters reflecting platelet size, known as platelet volume indices (PVI), are raised in patients with thrombosis and can predict poor outcomes. This systematic review evaluates the potential for PVI to be used as a predictor of COVID-19 morbidity and mortality.

Methods

English and Chinese databases were searched electronically to identify studies reporting data on mean platelet volume, platelet distribution width or platelet-large cell ratio in COVID-19 patients. Included articles underwent a quality rating and descriptive narrative analysis.

Results

Thirty-two studies were included in the systematic review. The results show a general trend for PVI to be raised in severe COVID-19 patients and non-survivors, with 14 studies reporting significant differences of baseline PVI between severe and mild disease. Nonetheless, longitudinal studies showed varying PVI trends over the course of the disease and evidence for PVI to be associated with disease progression was limited. The quality rating of 12 studies was poor, 16 were rated fair and four were good. Most studies were retrospective in design, used small study populations and did not consider confounding factors that influence platelet volume. Studies also contained technical flaws in PVI measurement, limiting the reliability of the results.

Conclusion

The evidence on the clinical usefulness of PVI is greatly limited by the lack of prospective evaluation, together with technical problems in measuring PVI. Carefully designed prospective studies are warranted.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=304305, identifier CRD42022304305.

Thromboinflammation as a Driver of Venous Thromboembolism

Thrombus formation has been identified as an integral part in innate immunity, termed immunothrombosis. Activation of host defense systems is known to result in a procoagulant environment. In this system, cellular players as well as soluble mediators interact with each other and their dysregulation can lead to the pathological process of thromboinflammation. These mechanisms have been under intensified investigation during the COVID-19 pandemic. In this review, we focus on the underlying mechanisms leading to thromboinflammation as one trigger of venous thromboembolism.

COVID-19 and Venous Thromboembolism: From Pathological Mechanisms to Clinical Management

Coronavirus disease 2019 (COVID-19), which is becoming a global pandemic, is caused by SARS-CoV-2 infection. In COVID-19, thrombotic events occur frequently, mainly venous thromboembolism (VTE), which is closely related to disease severity and clinical prognosis. Compared with historical controls, the occurrence of VTE in hospitalized and critical COVID-19 patients is incredibly high. However, the pathophysiology of thrombosis and the best strategies for thrombosis prevention in COVID-19 remain unclear, thus needing further exploration. Virchow’s triad elements have been proposed as important risk factors for thrombotic diseases. Therefore, the three factors outlined by Virchow can also be applied to the formation of venous thrombosis in the COVID-19 setting. A thorough understanding of the complex interactions in these processes is important in the search for effective treatments for COVID-19. In this work, we focus on the pathological mechanisms of VTE in COVID-19 from the aspects of endothelial dysfunction, hypercoagulability, abnormal blood flow. We also discuss the treatment of VTE as well as the ongoing clinical trials of heparin anticoagulant therapy. In addition, according to the pathophysiological mechanism of COVID-19-associated thrombosis, we extended the range of antithrombotic drugs including antiplatelet drugs, antifibrinolytic drugs, and anti-inflammatory drugs, hoping to find effective drug therapy and improve the prognosis of VTE in COVID-19 patients.

Targeting Inflammasome Activation in COVID-19: Delivery of RNA Interference-Based Therapeutic Molecules

Mortality and morbidity associated with COVID-19 continue to be significantly high worldwide, owing to the absence of effective treatment strategies. The emergence of different variants of SARS-CoV-2 is also a considerable source of concern and has led to challenges in the development of better prevention and treatment strategies, including vaccines. Immune dysregulation due to pro-inflammatory mediators has worsened the situation in COVID-19 patients. Inflammasomes play a critical role in modulating pro-inflammatory cytokines in the pathogenesis of COVID-19 and their activation is associated with poor clinical outcomes. Numerous preclinical and clinical trials for COVID-19 treatment using different approaches are currently underway. Targeting different inflammasomes to reduce the cytokine storm, and its associated complications, in COVID-19 patients is a new area of research. Non-coding RNAs, targeting inflammasome activation, may serve as an effective treatment strategy. However, the efficacy of these therapeutic agents is highly dependent on the delivery system. MicroRNAs and long non-coding RNAs, in conjunction with an efficient delivery vehicle, present a potential strategy for regulating NLRP3 activity through various RNA interference (RNAi) mechanisms. In this regard, the use of nanomaterials and other vehicle types for the delivery of RNAi-based therapeutic molecules for COVID-19 may serve as a novel approach for enhancing drug efficacy. The present review briefly summarizes immune dysregulation and its consequences, the roles of different non-coding RNAs in regulating the NLRP3 inflammasome, distinct types of vectors for their delivery, and potential therapeutic targets of microRNA for treatment of COVID-19.

Is there any relationship between serum zinc levels and angiotensin-converting enzyme 2 gene expression in patients with coronavirus disease 2019?

Background

The level of angiotensin-converting enzyme 2 (ACE2) expression in different tissues is essential in the sensitivity, symptoms and consequences of COVID-19 infection. It seems that zinc is involved in the structure of the ACE2 enzyme has been identified; nonetheless, the relationship between ACE2 expression and zinc serum levels in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected patients is still unclear. This study aimed to evaluate the expression of ACE2 in peripheral blood-derived immune cells of COVID-19 patients and its relationship with serum zinc levels.

Methods

Thirty healthy subjects and thirty patients with COVID-19 were enrolled in this study. The COVID-19 infection was confirmed by positive real-time polymerase chain reaction (RT-PCR) and radiological data. Peripheral blood samples were taken from healthy subjects and COVID-19 patients. Whole blood samples were also used to measure ACE2 gene expression by RT-PCR technique. The correlation matrix evaluated the relationship between ACE2 expression, serum zinc levels, and other related variables.

Results

The outcomes showed no considerable alteration in serum zinc levels between patients and the control group. Likewise, the ACE2 gene expression results showed a significant decrease in this receptor's expression in COVID-19 patients compared with the healthy subjects. A significant positive correlation was observed between serum zinc level and ACE2 gene expression in patients with COVID-19.

Conclusion

The immune system seems to reduce the mRNA expression of the ACE2 in the peripheral blood leukocytes following SARS-CoV-2 infection. Moreover, zinc deficiency can make patients more susceptible to SARS-CoV-2 infection.

Pulmonary Toxicities Associated With the Use of Immune Checkpoint Inhibitors: An Update From the Immuno-Oncology Subgroup of the Neutropenia, Infection & Myelosuppression Study Group of the Multinational Association for Supportive Care in Cancer

The development of immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, with agents such as nivolumab, pembrolizumab, and cemiplimab targeting programmed cell death protein-1 (PD-1) and durvalumab, avelumab, and atezolizumab targeting PD-ligand 1 (PD-L1). Ipilimumab targets cytotoxic T lymphocyte-associated antigen-4 (CTLA-4). These inhibitors have shown remarkable efficacy in melanoma, lung cancer, urothelial cancer, and a variety of solid tumors, either as single agents or in combination with other anticancer modalities. Additional indications are continuing to evolve. Checkpoint inhibitors are associated with less toxicity when compared to chemotherapy. These agents enhance the antitumor immune response and produce side- effects known as immune-related adverse events (irAEs). Although the incidence of immune checkpoint inhibitor pneumonitis (ICI-Pneumonitis) is relatively low, this complication is likely to cause the delay or cessation of immunotherapy and, in severe cases, may be associated with treatment-related mortality. The primary mechanism of ICI-Pneumonitis remains unclear, but it is believed to be associated with the immune dysregulation caused by ICIs. The development of irAEs may be related to increased T cell activity against cross-antigens expressed in tumor and normal tissues. Treatment with ICIs is associated with an increased number of activated alveolar T cells and reduced activity of the anti-inflammatory Treg phenotype, leading to dysregulation of T cell activity. This review discusses the pathogenesis of alveolar pneumonitis and the incidence, diagnosis, and clinical management of pulmonary toxicity, as well as the pulmonary complications of ICIs, either as monotherapy or in combination with other anticancer modalities, such as thoracic radiotherapy.

Interleukin-6 Perpetrator of the COVID-19 Cytokine Storm

COVID-19 has emerged as a global pandemic. It is mainly manifested as pneumonia which may deteriorate into severe respiratory failure. The major hallmark of the disease is the systemic inflammatory immune response characterized by Cytokine Storm (CS). CS is marked by elevated levels of inflammatory cytokines, mainly interleukin-6 (IL-6), IL-8, IL-10, tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ). Of these, IL-6 is found to be significantly associated with higher mortality. IL-6 is also a robust marker for predicting disease prognosis and deterioration of clinical profile. In this review, the pivotal role played by IL-6 in the immuno-pathology of COVID-19 has been illustrated. The role of IL-6 as a pleiotropic cytokine executing both pro and anti-inflammatory activities has been reviewed. ADAM 10, a metalloproteinase switches the anti-inflammatory pathway of IL-6 to pro inflammatory hence blocking the action of ADAM 10 could be a new therapeutic strategy to mitigate the proinflammatory action of IL-6. Furthermore, we explore the role of anti-IL6 agents, IL-6 receptor antibodies which were being used for autoimmune diseases but now are being repurposed for the therapy of COVID-19.

Thrombotic and Hypercoagulability Complications of COVID-19: An Update

The current COVID-19 pandemic emerged in December 2019, in China, affecting millions of people worldwide. COVID-19 is mainly a disease of the respiratory system, yet systematic complications have also been reported among SARS-CoV-2 infected patients. Thrombotic complications are one of the severe clinical outcomes of COVID-19, especially among critically ill patients, and are associated with poor prognosis. To date, many studies have concluded that COVID-19 increases the incidence of thrombotic events and coagulopathies; however, the exact mechanism behind such a disease outcome is not well known. Various pathophysiological mechanisms for thrombotic events in COVID-19 have been proposed, these include virus-induced endothelial cell damage, inflammation, and excess production of pro-inflammatory cytokines. As a result, most critically diseased COVID-19 patients are managed with prophylactic anticoagulant, yet some still develop thrombotic episodes. Therefore, better understanding of the mechanisms behind the thrombotic complications is needed to develop treatments that specifically target such pathways, which may aid in better disease management and improve the prognosis.

COVID-19 Immunobiology: Lessons Learned, New Questions Arise

There is strong evidence that COVID-19 pathophysiology is mainly driven by a spatiotemporal immune deregulation. Both its phenotypic heterogeneity, spanning from asymptomatic to severe disease/death, and its associated mortality, are dictated by and linked to maladaptive innate and adaptive immune responses against SARS-CoV-2, the etiologic factor of the disease. Deregulated interferon and cytokine responses, with the contribution of immune and cellular stress-response mediators (like cellular senescence or uncontrolled inflammatory cell death), result in innate and adaptive immune system malfunction, endothelial activation and inflammation (endothelitis), as well as immunothrombosis (with enhanced platelet activation, NET production/release and complement hyper-activation). All these factors play key roles in the development of severe COVID-19. Interestingly, another consequence of this immune deregulation, is the production of autoantibodies and the subsequent development of autoimmune phenomena observed in some COVID-19 patients with severe disease. These new aspects of the disease that are now emerging (like autoimmunity and cellular senescence), could offer us new opportunities in the field of disease prevention and treatment. Simultaneously, lessons already learned from the immunobiology of COVID-19 could offer new insights, not only for this disease, but also for a variety of chronic inflammatory responses observed in autoimmune and (auto)inflammatory diseases.

The Impact of Angiotensin-Converting Enzyme 2 (ACE2) Expression Levels in Patients with Comorbidities on COVID-19 Severity: A Comprehensive Review

Angiotensin-Converting Enzyme 2 (ACE2) has been proved to be the main host cell receptor for the binding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the COVID-19 pandemic. The SARS-CoV-2 spike (S) protein binds to ACE2 to initiate the process of replication. This enzyme is widely present in human organ tissues, such as the heart and lung. The pathophysiology of ACE2 in SARS-CoV-2 infection is complex and may be associated with several factors and conditions that are more severe in COVID-19 patients, such as age, male gender, and comorbidities, namely, cardiovascular diseases, chronic respiratory diseases, obesity, and diabetes. Here we present a comprehensive review that aims to correlate the levels of expression of the ACE2 in patients with comorbidities and with a poor outcome in COVID-19 disease. Significantly higher levels of expression of ACE2 were observed in myocardial and lung tissues in heart failure and COPD patients, respectively. An age-dependent increase in SARS2-CoV-2 receptors in the respiratory epithelium may be also responsible for the increased severity of COVID-19 lung disease in elderly people. Although the role of ACE2 is highlighted regarding the damage that can arise upon the SARS-CoV-2 invasion, there was no association observed between renin-angiotensin-aldosterone system (RAAS) inhibitors and the severity of COVID-19.

Course of COVID-19 Based on Admission D-Dimer Levels and Its Influence on Thrombosis and Mortality

Background

Arterial and venous thrombosis is one of the major complications of coronavirus disease 2019 (COVID-19) infection. Studies have not assessed the difference in D-dimer levels between patients who develop thrombosis and those who do not.

Methods

Our study retrospectively assessed D-dimer levels in all virus confirmed hospitalized patients between May to September, 2020. Patients were divided into three groups: group 1 with normal D-dimer of < 0.5 µg/mL, group 2 with elevation up to six folds, and group 3 with more than six-fold elevation. Statistical analysis was done using SPSS software 23.0.

Results

Seven hundred twenty patients (group1 (n = 414), group 2 (n = 284) and group 3 (n = 22)) were studied. Eight thrombotic events were observed. Events were two with stroke, two non-ST elevation myocardial infarction and one each of ST elevation myocardial infarction, superior mesenteric artery thrombosis with bowel gangrene, arteriovenous fistula thrombus and unstable angina. No significant difference (P = 0.11) was observed between median D-dimer levels among patients who developed thrombosis (1.34) and those who did not develop thrombosis (0.91). Twenty-nine patients died. The adjusted odds of death among those with a six-fold or higher elevation in D-dimer was 128.4 (95% confidence interval (CI): 14.2 - 446.3, P < 0.001), while adjusted odds of developing clinical thrombosis was 1.96 (95% CI: 0.82 - 18.2, P = 0.18).

Conclusions

Our study observed a 1.1% in-hospital incidence of clinical thrombosis. While, a six-fold elevation in D-dimer was significantly associated with death; the same was not a strong predictor of thrombosis; an observation which implies that dose of anticoagulation should not be based on absolute D-dimer level.

Inflammation in COVID-19: from pathogenesis to treatment

The coronavirus disease 2019 (COVID-19) was declared a pandemic in March 2020 by the World Health Organization (WHO). To date, there were > 163 million confirmed cases of COVID-19 and the disease has claimed > 3.3 million lives globally. As with many other diseases, inflammation is a key feature of COVID-19. When inflammation is overwhelming, it may lead to unfavorable outcomes or even death. Scientists all over the world are working tirelessly in search of therapeutic strategies to suppress or modulate inflammation in COVID-19. This review gives an overview of the role of inflammation in COVID-19. It also critically examines the various treatment approaches that target the immune system and inflammation in COVID-19, as well as highlights the key findings in the numerous studies conducted thus far.

The SARS-CoV-2/Receptor Axis in Heart and Blood Vessels: A Crisp Update on COVID-19 Disease with Cardiovascular Complications

The SARS-CoV-2 virus causing COVID-19 disease has emerged expeditiously in the world and has been declared pandemic since March 2020, by World Health Organization (WHO). The destructive effects of SARS-CoV-2 infection are increased among the patients with pre-existing chronic conditions and, in particular, this review focuses on patients with underlying cardiovascular complications. The expression pattern and potential functions of SARS-CoV-2 binding receptors and the attributes of SARS-CoV-2 virus tropism in a physio-pathological state of heart and blood vessel are precisely described. Of note, the atheroprotective role of ACE2 receptors is reviewed. A detailed description of the possible detrimental role of SARS-CoV-2 infection in terms of vascular leakage, including endothelial glycocalyx dysfunction and bradykinin 1 receptor stimulation is concisely stated. Furthermore, the potential molecular mechanisms underlying SARS-CoV-2 induced clot formation in association with host defense components, including activation of FXIIa, complements and platelets, endothelial dysfunction, immune cell responses with cytokine-mediated action are well elaborated. Moreover, a brief clinical update on patient with COVID-19 disease with underlying cardiovascular complications and those who had new onset of cardiovascular complications post-COVID-19 disease was also discussed. Taken together, this review provides an overview of the mechanistic aspects of SARS-CoV-2 induced devastating effects, in vital organs such as the heart and vessels.

Endothelium Activation Markers in Severe Hospitalized COVID-19 Patients: Role in Mortality Risk Prediction

Introduction  Endothelial damage and hypercoagulability are major players behind the hemostatic derangement of SARS-CoV-2 infection.

Aim  In this prospective study we assessed endothelial and inflammatory biomarkers in a cohort of COVID-19 patients, aiming to identify predictive factors of in-hospital mortality.

Methods  COVID-19 patients hospitalized in intensive care (ICU) and non-ICU units at 2 Bergamo (Italy) hospitals from March 23 to May 30, 2020, were enrolled. Markers of endothelium activation including von-Willebrand factor (vWF), soluble thrombomodulin (sTM), and fibrinolytic proteins (t-PA and PAI-1) were measured. Additionally, D-dimer, Fibrinogen, FVIII, nucleosomes, C reactive protein (CRP) and procalcitonin were assessed.

Results  Sixty-three (45 ICU, and 18 non-ICU) patients, with a median age of 62 years were analyzed. Increased plasma levels of D-dimer, FVIII, fibrinogen, nucleosomes, CRP, and procalcitonin were observed in the whole cohort. Extremely elevated vWF levels characterized all patients (highest values in ICU-subjects). After a median time of 30 days, death occurred in 13 (21%) patients. By multivariable analysis, vWF-activity, neutrophil-count and PaO2/FiO2 were significantly associated with death. Using these variables, a linear score with 3-risk groups was generated that provided a cumulative incidence of death of 0% in the low-, 32% in the intermediate-, and 78% in the high-risk group.

Conclusions  COVID-19-induced hemostatic abnormalities are exacerbated by the severity of the disease and strongly correlate with the inflammatory status, underlying the link between coagulation, endothelial activation, and inflammation. Our study provides evidence for a role of vWF, together with neutrophils and PaO2/FiO2, as a significant predictor of in-hospital mortality by SARSCoV-2 infection.

Genetic and epigenetic control of ACE2 expression and its possible role in COVID-19

Coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2), is a pandemic that is claiming hundreds of thousands of lives around the world. Angiotensin‐converting enzyme‐2 (ACE2) is a key player in COVID‐19 due to its pivotal role in the SARS‐CoV‐2 infection. This enzyme is expressed throughout the body and the studies conducted so far have shown that its expression varies according to several factors, including cell type, sex, age, disease states and probably SARS‐CoV‐2 infection. Single‐nucleotide polymorphisms (SNPs) and epigenetic mechanisms, including DNA methylation, histone post‐translational modifications and microRNAs, impact ACE2 expression and may explain structural variation. The understanding of how genetic variants and epigenetic markers act to control ACE2 expression in health and disease states may contribute to comprehend several aspects of COVID‐19 that are puzzling researchers and clinicians. This review collects and appraises the literature regarding some aspects in the ACE2 biology, the expression patterns of this molecule, SNPs of the ACE2 gene and epigenetic mechanisms that may impact ACE2 expression in the context of COVID‐19.

The role of IL-6 and IL-6 blockade in COVID-19

INTRODUCTION

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces a dysregulated hyperinflammatory response.

AREAS COVERED

Authors review evidence on IL-6 and IL-6 blockade in coronavirus disease 2019 (COVID-19) and discuss the pathophysiological and prognostic roles of this cytokine and the clinical impact of pharmacological blockade of IL-6 . The material includes original articles and reviews published from March 2020 to March 2021 and searched on PubMed, medRxiv, and bioRxiv.

EXPERT OPINION

IL-6 is one of the most prominent pro-inflammatory cytokines. Increased levels are recorded in COVID-19 patients, especially those with severe-to-critical disease. Evidence is accumulating on the relevance of IL-6 as a prognostic marker in COVID-19. Since IL-6 is a druggable target for several inflammatory diseases, pharmacological blockers of the IL-6 signaling pathway were repurposed to blunt the abnormal SARS-CoV-2-induced cytokine release. Data are limited to few randomized controlled trials that reported encouraging, though not conclusive, results, indicating the usefulness of IL-6 blockade early in the course of the disease in patients with hyperinflammation and no or limited organ damage. Further research is warranted to explore the role of IL-6 in different COVID-19 phenotypes and identify subgroups of patients who may mostly benefit from IL-6 pathway inhibition.

COVID-19 and HIV infection co-pandemics and their impact: a review of the literature

Coronavirus disease 2019 (COVID-19) was first detected in December 2019. In March 2020, the World Health Organization declared COVID-19 a pandemic. People with underlying medical conditions may be at greater risk of infection and experience complications from COVID-19. COVID-19 has the potential to affect People living with HIV (PLWH) in various ways, including be increased risk of COVID-19 acquisition and interruptions of HIV treatment and care. The purpose of this review article is to evaluate the impact of COVID-19 among PLWH. The contents focus on 4 topics: (1) the pathophysiology and host immune response of people infected with both SARS-CoV-2 and HIV, (2) present the clinical manifestations and treatment outcomes of persons with co-infection, (3) assess the impact of antiretroviral HIV drugs among PLWH infected with COVID-19 and (4) evaluate the impact of the COVID-19 pandemic on HIV services.

Endothelial Dysfunction in the Brain: Setting the Stage for Stroke and Other Cerebrovascular Complications of COVID-19

The Coronavirus disease 2019 (COVID)-19 pandemic has already affected millions worldwide, with a current mortality rate of 2.2%. While it is well-established that severe acute respiratory syndrome-coronavirus-2 causes upper and lower respiratory tract infections, a number of neurological sequelae have now been reported in a large proportion of cases. Additionally, the disease causes arterial and venous thromboses including pulmonary embolism, myocardial infarction, and a significant number of cerebrovascular complications. The increasing incidence of large vessel ischemic strokes as well as intracranial hemorrhages, frequently in younger individuals, and associated with increased morbidity and mortality, has raised questions as to why the brain is a major target of the disease. COVID-19 is characterized by hypercoagulability with alterations in hemostatic markers including high D-dimer levels, which are a prognosticator of poor outcome. Together with findings of fibrin-rich microthrombi, widespread extracellular fibrin deposition in affected various organs and hypercytokinemia, this suggests that COVID-19 is more than a pulmonary viral infection. Evidently, COVID-19 is a thrombo-inflammatory disease. Endothelial cells that constitute the lining of blood vessels are the primary targets of a thrombo-inflammatory response, and severe acute respiratory syndrome coronavirus 2 also directly infects endothelial cells through the ACE2 (angiotensin-converting enzyme 2) receptor. Being highly heterogeneous in their structure and function, differences in the endothelial cells may govern the susceptibility of organs to COVID-19. Here, we have explored how the unique characteristics of the cerebral endothelium may be the underlying reason for the increased rates of cerebrovascular pathology associated with COVID-19.