Physiological and Immunological Causes of the Susceptibility of Chronic Inflammatory Patients to COVID-19 Infection: Focus on Diabetes

The Impact of Comorbidities and Obesity on the Severity and Outcome of COVID-19 in Hospitalized Patients-A Retrospective Study in a Hungarian Hospital

Patients with comorbidities and obesity are more likely to be hospitalized with coronavirus disease 2019 (COVID-19), to have a higher incidence of severe pneumonia and to also show higher mortality rates. Between 15 March 2020 and 31 December 2021, a retrospective, single-center, observational study was conducted among patients requiring hospitalization for COVID-19 infection. Our aim was to investigate the impact of comorbidities and lifestyle risk factors on mortality, the need for intensive care unit (ICU) admission and the severity of the disease among these patients. Our results demonstrated that comorbidities and obesity increased the risk for all investigated endpoints. Age over 65 years and male sex were identified as independent risk factors, and cardiovascular diseases, cancer, endocrine and metabolic diseases, chronic kidney disease and obesity were identified as significant risk factors. Obesity was found to be the most significant risk factor, associated with considerable odds of COVID-19 mortality and the need for ICU admission in the under-65 age group (aOR: 2.95; p < 0.001 and aOR: 3.49, p < 0.001). In our study, risk factors that increased mortality and morbidity among hospitalized patients were identified. Detailed information on such factors may support therapeutic decision making, the proper targeting of vaccination campaigns and the effective overall management of the COVID-19 epidemic, hence reducing the burden on the healthcare system.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

New insights on circular RNAs and their potential applications as biomarkers, therapeutic agents, and preventive vaccines in viral infections: with a glance at SARS-CoV-2

The occurrence of viral infections and approaches to handling them are very challenging and require prompt diagnosis and timely treatment. Recently, genomic medicine approaches have come up with the discovery of the competing endogenous RNA (ceRNA) network, including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs) on the basis of gene silencing. CircRNAs, as a group of non-encoded RNAs, make a loop-like structure by back-splicing through 3' and 5' ends. They are stable, abundant, specific, and highly conserved and can be quickly generated at large scales in vitro. CircRNAs have the potential to contribute in several cellular processes in a way that some serve as microRNA sponges, cellular transporters, protein-binding RNAs, transcriptional regulators, and immune system modulators. CircRNAs can even play an important role in modulating antiviral immune responses. In the present review, circRNAs' biogenesis, function, and biomarker and therapeutic potential as well as their prospective applications as vaccines against viral infections such as SARS-CoV-2 are explained. By considering their unique properties, their potential to be used as novel vaccines, biomarkers, and a therapeutic approach appears possible.

The impact of obesity and dyslipidemia on Remdesivir effectiveness in hospitalized patients with SARS-CoV-2-related pneumonia: An observational study

BACKGROUND AND AIMS

Remdesivir (GS-5734), an inhibitor of the viral RNA-dependent, RNA polymerase was early identified as a promising therapeutic candidate against COVID-19. Our aim was to evaluate the impact of several metabolic parameters on Remdesivir effectiveness among hospitalized COVID-19 patients.

METHODS AND RESULTS

We conducted an observational study on patients with SARS-CoV-2-related pneumonia admitted between May 2020 and September 2021 to the COVID-19 Units of Internal Medicine, Pneumology and Intensive Care of Garibaldi Hospital, Catania, Italy, and treated with Remdesivir. The "Ordinal Scale For Clinical Improvement" was used to assess patients' clinical improvement within 28 days of hospitalization. Short-term mortality rate was also evaluated. A total of 142 patients with SARS-CoV-2-related pneumonia were studied. The prevalence of obesity (20.7% vs. 41.9%, p = 0.03), the average BMI (27.1 ± 4.4 vs. 31.1 ± 6.1, p < 0.01) and the mean LDL-C levels (78 ± 19 mg/dl vs. 103 ± 18 mg/dl, p = 0.03) were significantly lower in early-improved (EI) compared to not-improved (NI) individuals. Obesity was negatively associated to clinical improvement after Remdesivir (OR 0.48, 95%CI 0.17-0.97, p = 0.04). Both obesity (OR 2.82, 95% CI 1.05-7.71, p = 0.04) and dyslipidemia (OR 2.78, 95%CI 1.17-7.16, p = 0.03) were significantly related to patients' mortality. Dyslipidemic subjects experienced a slower clinical improvement than non-dyslipidemic ones (Long-Rank p = 0.04).

CONCLUSION

Our study showed that unfavorable metabolic conditions such as obesity and dyslipidemia could predict a worse clinical response to Remdesivir as well as the mortality in hospitalized COVID-19 patients. Further prospective and larger-scale studies are needed to confirm these preliminary findings.

CD8+ T Cells in SARS-CoV-2 Induced Disease and Cancer-Clinical Perspectives

Dysregulated innate and adaptive immunity is a sign of SARS-CoV-2-induced disease and cancer. CD8+ T cells are important cells of the immune system. The cells belong to the adaptive immunity and take a front-line defense against viral infections and cancer. Extreme CD8+ T-cell activities in the lung of patients with a SARS-CoV-2-induced disease and within the tumor microenvironment (TME) will change their functionality into exhausted state and undergo apoptosis. Such diminished immunity will put cancer cases at a high-risk group for SARS-CoV-2-induced disease, rendering viral sepsis and a more severe condition which will finally cause a higher rate of mortality. Recovering responses from CD8+ T cells is a purpose of vaccination against SARS-CoV-2. The aim of this review is to discuss the CD8+ T cellular state in SARS-CoV-2-induced disease and in cancer and to present some strategies for recovering the functionality of these critical cells.

Hyperlipidemia and Obesity's Role in Immune Dysregulation Underlying the Severity of COVID-19 Infection

Obesity and hyperlipidemia are known to be risk factors for various pathological disorders, including various forms of infectious respiratory disease, including the current Coronavirus outbreak termed Coronavirus Disease 19 (COVID-19). This review studies the effects of hyperlipidemia and obesity on enhancing the inflammatory response seen in COVID-19 and potential therapeutic pathways related to these processes. In order to better understand the underlying processes of cytokine and chemokine-induced inflammation, we must further investigate the immunomodulatory effects of agents such as Vitamin D and the reduced form of glutathione as adjunctive therapies for COVID-19 disease.