From nicotine to the cholinergic anti-inflammatory reflex - Can nicotine alleviate the dysregulated inflammation in COVID-19?

Alpha-7 Nicotinic Receptor Agonist Protects Mice Against Pulmonary Emphysema Induced by Elastase

Pulmonary emphysema is a primary component of chronic obstructive pulmonary disease (COPD), a life-threatening disorder characterized by lung inflammation and restricted airflow, primarily resulting from the destruction of small airways and alveolar walls. Cumulative evidence suggests that nicotinic receptors, especially the α7 subtype (α7nAChR), is required for anti-inflammatory cholinergic responses. We postulated that the stimulation of α7nAChR could offer therapeutic benefits in the context of pulmonary emphysema. To investigate this, we assessed the potential protective effects of PNU-282987, a selective α7nAChR agonist, using an experimental emphysema model. Male mice (C57BL/6) were submitted to a nasal instillation of porcine pancreatic elastase (PPE) (50 µl, 0.667 IU) to induce emphysema. Treatment with PNU-282987 (2.0 mg/kg, ip) was performed pre and post-emphysema induction by measuring anti-inflammatory effects (inflammatory cells, cytokines) as well as anti-remodeling and anti-oxidant effects. Elastase-induced emphysema led to an increase in the number of α7nAChR-positive cells in the lungs. Notably, both groups treated with PNU-282987 (prior to and following emphysema induction) exhibited a significant decrease in the number of α7nAChR-positive cells. Furthermore, both groups treated with PNU-282987 demonstrated decreased levels of macrophages, IL-6, IL-1β, collagen, and elastic fiber deposition. Additionally, both groups exhibited reduced STAT3 phosphorylation and lower levels of SOCS3. Of particular note, in the post-treated group, PNU-282987 successfully attenuated alveolar enlargement, decreased IL-17 and TNF-α levels, and reduced the recruitment of polymorphonuclear cells to the lung parenchyma. Significantly, it is worth noting that MLA, an antagonist of α7nAChR, counteracted the protective effects of PNU-282987 in relation to certain crucial inflammatory parameters. In summary, these findings unequivocally demonstrate the protective abilities of α7nAChR against elastase-induced emphysema, strongly supporting α7nAChR as a pivotal therapeutic target for ameliorating pulmonary emphysema.

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.

Nicotinic acetylcholine receptors: Therapeutic targets for novel ligands to treat pain and inflammation

Nicotinic acetylcholine receptors (nAChRs) have been historically defined as ligand-gated ion channels and function as such in the central and peripheral nervous systems. Recently, however, non-ionic signaling mechanisms via nAChRs have been demonstrated in immune cells. Furthermore, the signaling pathways where nAChRs are expressed can be activated by endogenous ligands other than the canonical agonists acetylcholine and choline. In this review, we discuss the involvement of a subset of nAChRs containing α7, α9, and/or α10 subunits in the modulation of pain and inflammation via the cholinergic anti-inflammatory pathway. Additionally, we review the most recent advances in the development of novel ligands and their potential as therapeutics.

Association between serum HMGB1 elevation and early pediatric acute respiratory distress syndrome: a retrospective study of pediatric living donor liver transplant recipients with biliary atresia in China

BACKGROUND

High mobility group box 1 (HMGB1) protein is one of the main risk factors for pediatric acute respiratory distress syndrome (PARDS) after living donor liver transplantation (LDLT). However, studies of the relationship between HMGB1 and PARDS are lacking. We evaluated the link between anomalies of intraoperative serum HMGB1 and PARDS in pediatric LDLT recipients with biliary atresia during the first week after transplant.

METHODS

Data for 210 pediatric patients with biliary atresia who underwent LDLT between January 2018 and December 2021 were reviewed retrospectively. The main measure was serum HMGB1 levels 30 min after reperfusion, while the outcome was early PARDS after LDLT. Data including pretransplant conditions, laboratory indexes, variables of intraoperation, clinical complications, and outcomes after LDLT were analyzed for each patient. Univariate analysis of PARDS and multivariate logistic regression analyses of serum HMGB1 levels at 30 min in the neohepatic phase in the presence of PARDS were conducted to examine the potential associations. Subgroup interaction analyses and linear relationships between intraoperative serum HMGB1 levels and PARDS were also performed.

RESULTS

Among the participants, 55 had PARDS during 7 days after LDLT, including four in the first HMGB1 tertile (4.3-8.1 pg/mL), 18 in the second tertile (8.2-10.6 pg/mL), and 33 in the third tertile (10.6-18.8 pg/mL). The nonadjusted association between intraoperative HMGB1 levels and PARDS was positive (odds ratio 1.41, 95% confidence intervals 1.24-1.61, P < 0.0001). The association remained unchanged after adjustment for age, weight, pretransplant total bilirubin, albumin, graft cold ischemia time, and intraoperative blood loss volume (odds ratio 1.28, 95% confidence interval 1.10-1.49, P = 0.0017). After controlling for potential confounders, the association between intraoperative HMGB1 levels and PARDS remained positive, as well as in the subgroup analyses.

CONCLUSIONS

Serum HMGB1 levels at 30 min after reperfusion were positively associated with early PARDS among pediatric patients with biliary atresia who had undergone LDLT. Identifying such patients early may increase the efficacy of perioperative respiratory management.

The Role of the Acetylcholine System in Common Respiratory Diseases and COVID-19

As an indispensable component in human beings, the acetylcholine system regulates multiple physiological processes not only in neuronal tissues but also in nonneuronal tissues. However, since the concept of the "Nonneuronal cholinergic system (NNCS)" has been proposed, the role of the acetylcholine system in nonneuronal tissues has received increasing attention. A growing body of research shows that the acetylcholine system also participates in modulating inflammatory responses, regulating contraction and mucus secretion of respiratory tracts, and influencing the metastasis and invasion of lung cancer. In addition, the susceptibility and severity of respiratory tract infections caused by pathogens such as Mycobacterium Tuberculosis and the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) can also correlate with the regulation of the acetylcholine system. In this review, we summarized the major roles of the acetylcholine system in respiratory diseases. Despite existing achievements in the field of the acetylcholine system, we hope that more in-depth investigations on this topic will be conducted to unearth more possible pharmaceutical applications for the treatment of diverse respiratory diseases.

Current tobacco use and COVID-19 diagnoses in a cohort of adult clients of public dental clinics in Sweden

Smoking has been linked with both increased and decreased risk of COVID-19, prompting the hypothesis of a protective role of nicotine in the pathogenesis of the disease. Studies of the association between use of smokeless tobacco and COVID-19 would help refining this hypothesis. We analysed data from 424,386 residents in the Stockholm Region, Sweden, with information on smoking and smokeless tobacco (snus) use prior to the pandemic obtained from dental records. Diagnoses of COVID-19 between February and October 2020 were obtained from health-care registers. We estimated the risk of receiving a diagnosis of COVID-19 for current smokers and for current snus users relative to non-users of tobacco, adjusting for potential confounders (aRR). The aRR of COVID -19 was elevated for current snus users (1.09 ;95%CI = 0.99-1.21 among men and 1.15; 95%CI = 1.00-1.33 among women). The risk for women consuming more than 1 can/day was twice as high as among non-users of tobacco. Current smoking was negatively associated with risk of COVID-19 (aRR = 0.68; 95% CI = 0.61-0.75); including hospital admission (aRR = 0.60; 95% CI = 0.47-0.76) and intensive care (aRR = 0.43; 95% CI = 0.21-0.89). The hypothesis of a protective effect of tobacco nicotine on COVID-19 was not supported by the findings. The negative association between smoking and COVID-19 remains unexplained.

GAT107-mediated α7 nicotinic acetylcholine receptor signaling attenuates inflammatory lung injury and mortality in a mouse model of ventilator-associated pneumonia by alleviating macrophage mitochondrial oxidative stress via reducing MnSOD-S-glutathionylation

Supraphysiological concentrations of oxygen (hyperoxia) can compromise host defense and increase susceptibility to bacterial and viral infections, causing ventilator-associated pneumonia (VAP). Compromised host defense and inflammatory lung injury are mediated, in part, by high extracellular concentrations of HMGB1, which can be decreased by GTS-21, a partial agonist of α7 nicotinic acetylcholine receptor (α7nAChR). Here, we report that a novel α7nAChR agonistic positive allosteric modulator (ago-PAM), GAT107, at 3.3 mg/kg, i.p., significantly decreased animal mortality and markers of inflammatory injury in mice exposed to hyperoxia and subsequently infected with Pseudomonas aeruginosa. The incubation of macrophages with 3.3 μM of GAT107 significantly decreased hyperoxia-induced extracellular HMGB1 accumulation and HMGB1-induced macrophage phagocytic dysfunction. Hyperoxia-compromised macrophage function was correlated with impaired mitochondrial membrane integrity, increased superoxide levels, and decreased manganese superoxide dismutase (MnSOD) activity. This compromised MnSOD activity is due to a significant increase in its level of glutathionylation. The incubation of hyperoxic macrophages with 3.3 μM of GAT107 significantly decreases the levels of glutathionylated MnSOD, and restores MnSOD activity and mitochondrial membrane integrity. Thus, GAT107 restored hyperoxia-compromised phagocytic functions by decreasing HMGB1 release, most likely via a mitochondrial-directed pathway. Overall, our results suggest that GAT107 may be a potential treatment to decrease acute inflammatory lung injury by increasing host defense in patients with VAP.

Medications Associated with Lower Mortality in a SARS-CoV-2 Positive Cohort of 26,508 Veterans

BACKGROUND

Many severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) positive patients take commonly prescribed medications with properties which may affect mortality.

OBJECTIVE

Assess if common medications postulated to affect clinical outcomes are associated with mortality in SARS-CoV-2 positive patients in the Veterans Health Administration (VHA).

DESIGN

Observational national cohort analysis.

PARTICIPANTS

Consecutive 26,508 SARS-CoV-2 positive Veterans (7% of 399,290 tested from March 1 to September 10, 2020) constitute the study cohort.

MAIN MEASURES

The primary outcome was 30-day mortality from the first positive SARS-CoV-2 test date. In patients receiving medications or drug pairs within 2 weeks post-SARS-CoV-2 positive test, 30-day mortality was estimated as relative risk (RR) on the log-binomial scale or using multinomial models with and without adjusting for covariates.

KEY RESULTS

The 26,508 SARS-CoV-2 positive patients were predominantly male (89%) and White (59%), and 82% were overweight/obese. Medications associated with decreased 30-day mortality risk included the following: metformin (aRR, 0.33; 95% CI, 0.25-0.43), colchicine, angiotensin-converting-enzyme inhibitors (ACEi), angiotensin II receptor blockers, statins, vitamin D, antihistamines, alpha-blockers, anti-androgens, and nonsteroidal anti-inflammatory drugs (aRR, 0.69; 95% CI, 0.61-0.78). The effect of co-prescribed medications on 30-day mortality risk revealed the lowest risk for combined statins and metformin (aRR, 0.21; 95% CI, 0.15-0.31), followed by ACEi and statins (aRR, 0.25; 95% CI, 0.18-0.35), ACEi and metformin (aRR, 0.26; 95% CI, 0.17-0.40), antihistamines and NSAIDs (aRR, 0.41; 95% CI, 0.32-0.52), and in men, combined alpha-blockers and anti-androgens (aRR, 0.51; 95% CI, 0.42-0.64).

CONCLUSIONS

In this large national cohort, treatment of SARS-CoV-2 positive patients with individual or co-prescribed metformin and statins, ACEi and statins (or metformin) and other medications was associated with a markedly decreased 30-day mortality and can likely be continued safely. Clinical trials may assess their therapeutic benefit.

Smoking Status, Nicotine Medication, Vaccination, and COVID-19 Hospital Outcomes: Findings from the COVID EHR Cohort at the University of Wisconsin (CEC-UW) Study

INTRODUCTION

Available evidence is mixed concerning associations between smoking status and COVID-19 clinical outcomes. Effects of nicotine replacement therapy (NRT) and vaccination status on COVID-19 outcomes in smokers are unknown.

METHODS

Electronic health record data from 104 590 COVID-19 patients hospitalized February 1, 2020 to September 30, 2021 in 21 U.S. health systems were analyzed to assess associations of smoking status, in-hospital NRT prescription, and vaccination status with in-hospital death and ICU admission.

RESULTS

Current (n = 7764) and never smokers (n = 57 454) did not differ on outcomes after adjustment for age, sex, race, ethnicity, insurance, body mass index, and comorbidities. Former (vs never) smokers (n = 33 101) had higher adjusted odds of death (aOR, 1.11; 95% CI, 1.06-1.17) and ICU admission (aOR, 1.07; 95% CI, 1.04-1.11). Among current smokers, NRT prescription was associated with reduced mortality (aOR, 0.64; 95% CI, 0.50-0.82). Vaccination effects were significantly moderated by smoking status; vaccination was more strongly associated with reduced mortality among current (aOR, 0.29; 95% CI, 0.16-0.66) and former smokers (aOR, 0.47; 95% CI, 0.39-0.57) than for never smokers (aOR, 0.67; 95% CI, 0.57, 0.79). Vaccination was associated with reduced ICU admission more strongly among former (aOR, 0.74; 95% CI, 0.66-0.83) than never smokers (aOR, 0.87; 95% CI, 0.79-0.97).

CONCLUSIONS

Former but not current smokers hospitalized with COVID-19 are at higher risk for severe outcomes. SARS-CoV-2 vaccination is associated with better hospital outcomes in COVID-19 patients, especially current and former smokers. NRT during COVID-19 hospitalization may reduce mortality for current smokers.

IMPLICATIONS

Prior findings regarding associations between smoking and severe COVID-19 disease outcomes have been inconsistent. This large cohort study suggests potential beneficial effects of nicotine replacement therapy on COVID-19 outcomes in current smokers and outsized benefits of SARS-CoV-2 vaccination in current and former smokers. Such findings may influence clinical practice and prevention efforts and motivate additional research that explores mechanisms for these effects.

Dual effects of supplemental oxygen on pulmonary infection, inflammatory lung injury, and neuromodulation in aging and COVID-19

Clinical studies have shown a significant positive correlation between age and the likelihood of being infected with SARS-CoV-2. This increased susceptibility is positively correlated with chronic inflammation and compromised neurocognitive functions. Postmortem analyses suggest that acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), with systemic and lung hyperinflammation, can cause significant morbidity and mortality in COVID-19 patients. Supraphysiological supplemental oxygen, also known as hyperoxia, is commonly used to treat decreased blood oxygen saturation in COVID-19 patients. However, prolonged exposure to hyperoxia alone can cause oxygen toxicity, due to an excessive increase in the levels of reactive oxygen species (ROS), which can overwhelm the cellular antioxidant capacity. Subsequently, this causes oxidative cellular damage and increased levels of aging biomarkers, such as telomere shortening and inflammaging. The oxidative stress in the lungs and brain can compromise innate immunity, resulting in an increased susceptibility to secondary lung infections, impaired neurocognitive functions, and dysregulated hyperinflammation, which can lead to ALI/ARDS, and even death. Studies indicate that lung inflammation is regulated by the central nervous system, notably, the cholinergic anti-inflammatory pathway (CAIP), which is innervated by the vagus nerve and α7 nicotinic acetylcholine receptors (α7nAChRs) on lung cells, particularly lung macrophages. The activation of α7nAChRs attenuates oxygen toxicity in the lungs and improves clinical outcomes by restoring hyperoxia-compromised innate immunity. Mechanistically, α7nAChR agonist (e.g., GAT 107 and GTS-21) can regulate redox signaling by 1) activating Nrf2, a master regulator of the antioxidant response and a cytoprotective defense system, which can decrease cellular damage caused by ROS and 2) inhibiting the activation of the NF-κB-mediated inflammatory response. Notably, GTS-21 has been shown to be safe and it improves neurocognitive functions in humans. Therefore, targeting the α7nAChR may represent a viable therapeutic approach for attenuating dysregulated hyperinflammation-mediated ARDS and sepsis in COVID-19 patients receiving prolonged oxygen therapy.

Association between smoking and COVID-19 severity: A multicentre retrospective observational study

The relationship between smoking and coronavirus disease 2019 (COVID-19) severity remains unclear. This study aimed to investigate the effect of smoking status (current smoking and a smoking history) on the clinical severity of COVID-19. Data of all enrolled 588 patients, who were referred to 25 hospitals in Jiangsu province between January 10, 2020 and March 14, 2020, were retrospectively reviewed. Univariate and multivariate regression, random forest algorithms, and additive interaction were used to estimate the importance of selective predictor variables in the relationship between smoking and COVID-19 severity. In the univariate analysis, the proportion of patients with a current smoking status in the severe group was significantly higher than that in the non-severe group. In the multivariate analysis, current smoking remained a risk factor for severe COVID-19. Data from the interaction analysis showed a strong interaction between the number of comorbidities in patients with COVID-19 and smoking. However, no significant interaction was found between smoking and specific comorbidities, such as hypertension, diabetes, etc. In the random forest model, smoking history was ranked sixth in mean decrease accuracy. Active smoking may be significantly associated with an enhanced risk of COVID-19 progression towards severe disease. However, additional prospective studies are needed to clarify the complex relationship between smoking and COVID-19 severity.

Famotidine activates the vagus nerve inflammatory reflex to attenuate cytokine storm

BACKGROUND

Severe COVID-19 is characterized by pro-inflammatory cytokine release syndrome (cytokine storm) which causes high morbidity and mortality. Recent observational and clinical studies suggest famotidine, a histamine 2 receptor (H2R) antagonist widely used to treat gastroesophageal reflux disease, attenuates the clinical course of COVID-19. Because evidence is lacking for a direct antiviral activity of famotidine, a proposed mechanism of action is blocking the effects of histamine released by mast cells. Here we hypothesized that famotidine activates the inflammatory reflex, a brain-integrated vagus nerve mechanism which inhibits inflammation via alpha 7 nicotinic acetylcholine receptor (α7nAChR) signal transduction, to prevent cytokine storm.

METHODS

The potential anti-inflammatory effects of famotidine and other H2R antagonists were assessed in mice exposed to lipopolysaccharide (LPS)-induced cytokine storm. As the inflammatory reflex is integrated and can be stimulated in the brain, and H2R antagonists penetrate the blood brain barrier poorly, famotidine was administered by intracerebroventricular (ICV) or intraperitoneal (IP) routes.

RESULTS

Famotidine administered IP significantly reduced serum and splenic LPS-stimulated tumor necrosis factor (TNF) and IL-6 concentrations, significantly improving survival. The effects of ICV famotidine were significantly more potent as compared to the peripheral route. Mice lacking mast cells by genetic deletion also responded to famotidine, indicating the anti-inflammatory effects are not mast cell-dependent. Either bilateral sub-diaphragmatic vagotomy or genetic knock-out of α7nAChR abolished the anti-inflammatory effects of famotidine, indicating the inflammatory reflex as famotidine's mechanism of action. While the structurally similar H2R antagonist tiotidine displayed equivalent anti-inflammatory activity, the H2R antagonists cimetidine or ranitidine were ineffective even at very high dosages.

CONCLUSIONS

These observations reveal a previously unidentified vagus nerve-dependent anti-inflammatory effect of famotidine in the setting of cytokine storm which is not replicated by high dosages of other H2R antagonists in clinical use. Because famotidine is more potent when administered intrathecally, these findings are also consistent with a primarily central nervous system mechanism of action.

Inflammatory reflex disruption in COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was identified in Wuhan, China, in late 2019 and caused coronavirus disease 2019 (COVID-19), which is still a global pandemic. In most infected people, SARS-CoV-2 can only cause moderate symptoms, while in other patients, it leads to severe illness and eventually death. Although the main clinical manifestation of COVID-19 is often seen in the lungs, this disease affects almost all body organs. The excessive and prolonged release of inflammatory cytokines that may occur in COVID-19 patients, known as cytokine storms, stimulates undesired immune responses and can cause various tissues damage. In the current review article, we focus on the potential advantages of the intrinsic cholinergic anti-inflammatory pathway (CAP) as the efferent arm of inflammatory reflex in COVID-19 management. Considering this endogenous protective mechanism against chronic inflammation, we focused on the effects of SARS-CoV-2 in the destruction of this anti-inflammatory system. Several studies indicated the interaction of SARS-CoV-2 with the alpha7 subtype of the nicotinic acetylcholine receptor as the effector molecule of the inflammatory reflex. On the other hand, neurological manifestations have increasingly been identified as significant extrapulmonary manifestations of COVID-19. The rational connection between these findings and COVID-19 pathogenesis may be an important issue in both our understanding and dealing with this disease. COVID-19 is deeply rooted in our daily life and requires an urgent need for the establishment of effective therapeutic options, and all the possible treatments must be considered for the control of such inflammatory conditions.

Oxigenación con membrana extracorpórea en el paciente COVID-19: resultados del Registro Español ECMO-COVID de la Sociedad Española de Cirugía Cardiovascular y Endovascular (SECCE)

Introducción y objetivos

La oxigenación con membrana extracorpórea (ECMO) ha resultado ser una opción terapéutica en los pacientes con insuficiencia respiratoria o cardiaca severa por COVID-19. Las indicaciones y manejo de estos pacientes están aún por determinar. Nuestro objetivo es evaluar los resultados de la terapia ECMO en pacientes con COVID-19 incluidos en un registro prospectivo e intentar optimizar los resultados.

Métodos

En marzo de 2020 se inició un registro multicéntrico anónimo prospectivo de pacientes con COVID-19 tratados mediante ECMO veno-arterial (V-A) o veno-venosa (V-V). Se registraron las variables clínicas, analíticas y respiratorias preimplante, datos de implante y evolución de la terapia. El evento primario fue la mortalidad hospitalaria de cualquier causa y los eventos secundarios fueron la recuperación funcional y el evento combinado de recuperación funcional y mortalidad de cualquier causa a partir de los 3 meses de seguimiento tras el alta.

Resultados

Se analizó a un total de 365 pacientes procedentes de 25 hospitales, 347 V-V y 18 V-A (edad media de 52,7 y 49,4 años, respectivamente). Los pacientes con ECMO V-V fueron más obesos, presentaban menos fracaso orgánico diferente al pulmonar y precisaron menos terapia inotrópica previa al implante. El 33,3% y el 34,9% de los pacientes con ECMO V-A y V-V, respectivamente, fueron dados de alta del hospital (p = NS) y la mortalidad fue similar, del 56,2% y 50,9% de los casos respectivamente, la inmensa mayoría durante la ECMO y sobre todo por fracaso multiorgánico. El 14,0% (51 pacientes) permanecían ingresados. El seguimiento medio fue de 196 ± 101,7 días. En el análisis multivariante, resultaron protectores de evento primario en pacientes con ECMO V-V el peso corporal (OR 0,967; IC 95%: 0,95-0,99; p = 0,004) y la procedencia del propio hospital (OR 0,48; IC 95%: 0,27-0,88; p = 0,018), mientras que la edad (OR 1,063; IC 95%: 1,005-1,12; p = 0,032), la hipertensión arterial (3,593; IC 95%: 1,06-12,19; p = 0,04) y las complicaciones en ECMO globales (2,44; IC 95%: 0,27-0,88; p = 0,019), digestivas (OR 4,23, IC 95%: 1,27-14,07; p = 0,019) y neurológicas (OR 4,66; IC 95%: 1,39-15,62; p = 0,013) fueron predictores independientes de mortalidad. El único predictor independiente de aparición de los eventos secundarios resultó el momento de seguimiento del paciente.

Conclusiones

La terapia con ECMO permite supervivencias hospitalarias hasta del 50% en pacientes con COVID-19 grave. La edad, la hipertensión arterial y las complicaciones en ECMO son los predictores de mortalidad hospitalaria en pacientes con ECMO V-V. Un mayor peso corporal y la procedencia del propio hospital son factores protectores. La recuperación funcional solo se ve influida por el tiempo de seguimiento transcurrido tras el alta. La estandarización de los criterios de implante y manejo del paciente con COVID grave mejoraría los resultados y la futura investigación clínica.

COVID-19 in Joint Ageing and Osteoarthritis: Current Status and Perspectives

COVID-19 is a trending topic worldwide due to its immense impact on society. Recent trends have shifted from acute effects towards the long-term morbidity of COVID-19. In this review, we hypothesize that SARS-CoV-2 contributes to age-related perturbations in endothelial and adipose tissue, which are known to characterize the early aging process. This would explain the long-lasting symptoms of SARS-CoV-2 as the result of an accelerated aging process. Connective tissues such as adipose tissue and musculoskeletal tissue are the primary sites of aging. Therefore, current literature was analyzed focusing on the musculoskeletal symptoms in COVID-19 patients. Hypovitaminosis D, increased fragility, and calcium deficiency point towards bone aging, while joint and muscle pain are typical for joint and muscle aging, respectively. These characteristics could be classified as early osteoarthritis-like phenotype. Exploration of the impact of SARS-CoV-2 and osteoarthritis on endothelial and adipose tissue, as well as neuronal function, showed similar perturbations. At a molecular level, this could be attributed to the angiotensin-converting enzyme 2 expression, renin-angiotensin system dysfunction, and inflammation. Finally, the influence of the nicotinic cholinergic system is being evaluated as a new treatment strategy. This is combined with the current knowledge of musculoskeletal aging to pave the road towards the treatment of long-term COVID-19.

Risk Factors Associated with the Clinical Outcomes of COVID-19 and Its Variants in the Context of Cytokine Storm and Therapeutics/Vaccine Development Challenges

The recent appearance of SARS-CoV-2 is responsible for the ongoing coronavirus disease 2019 (COVID-19) pandemic and has brought to light the importance of understanding this highly pathogenic agent to prevent future pandemics. This virus is from the same single-stranded positive-sense RNA family, Coronaviridae, as two other epidemic-causing viruses, SARS-CoV-1 and MERS-CoV. During this pandemic, one crucial focus highlighted by WHO has been to understand the risk factors that may contribute to disease severity and predict COVID-19 outcomes. In doing so, it is imperative to understand the virology of SARS-CoV-2 and the immunological response eliciting the clinical manifestation and progression of COVID-19. In this review, we provide clinical data-based analyses of how multiple risk factors (such as sex, race, HLA genotypes, blood groups, vitamin D deficiency, obesity, smoking, and asthma) contribute to the inflammatory overactivation and cytokine storm (frequently seen in COVID-19 patients) with a focus on the IL-6 pathway. We also draw comparisons to the virulence and pathophysiology of SARS and MERS to establish parallels in immune response and discuss the potential for therapeutic approaches that may limit disease progression in patients with higher risk profiles than others. Moreover, we cover the latest information on approved or upcoming COVID-19 vaccines. This paper also provides perspective on emerging variants and associated opportunistic infections such as black molds and fungus that have added to mortality in some parts of the world, such as India. This compilation of existing COVID-19 studies and data will provide an excellent referencing tool for the research, clinical, and public health communities.

COVID-19-Associated Mortality in US Veterans with and without SARS-CoV-2 Infection

Background: We performed an observational Veterans Health Administration cohort analysis to assess how risk factors affect 30-day mortality in SARS-CoV-2-infected subjects relative to those uninfected. While the risk factors for coronavirus disease 2019 (COVID-19) have been extensively studied, these have been seldom compared with uninfected referents. Methods: We analyzed 341,166 White/Black male veterans tested for SARS-CoV-2 from March 1 to September 10, 2020. The relative risk of 30-day mortality was computed for age, race, ethnicity, BMI, smoking status, and alcohol use disorder in infected and uninfected subjects separately. The difference in relative risk was then evaluated between infected and uninfected subjects. All the analyses were performed considering clinical confounders. Results: In this cohort, 7% were SARS-CoV-2-positive. Age >60 and overweight/obesity were associated with a dose-related increased mortality risk among infected patients relative to those uninfected. In contrast, relative to never smoking, current smoking was associated with a decreased mortality among infected and an increased mortality in uninfected, yielding a reduced mortality risk among infected relative to uninfected. Alcohol use disorder was also associated with decreased mortality risk in infected relative to the uninfected. Conclusions: Age, BMI, smoking, and alcohol use disorder affect 30-day mortality in SARS-CoV-2-infected subjects differently from uninfected referents. Advanced age and overweight/obesity were associated with increased mortality risk among infected men, while current smoking and alcohol use disorder were associated with lower mortality risk among infected men, when compared with those uninfected.

The Positive Allosteric Modulation of alpha7-Nicotinic Cholinergic Receptors by GAT107 Increases Bacterial Lung Clearance in Hyperoxic Mice by Decreasing Oxidative Stress in Macrophages

Supplemental oxygen therapy with supraphysiological concentrations of oxygen (hyperoxia; >21% O2) is a life-saving intervention for patients experiencing respiratory distress. However, prolonged exposure to hyperoxia can compromise bacterial clearance processes, due to oxidative stress-mediated impairment of macrophages, contributing to the increased susceptibility to pulmonary infections. This study reports that the activation of the α7 nicotinic acetylcholine receptor (α7nAChR) with the delete allosteric agonistic-positive allosteric modulator, GAT107, decreases the bacterial burden in mouse lungs by improving hyperoxia-induced lung redox imbalance. The incubation of RAW 264.7 cells with GAT107 (3.3 µM) rescues hyperoxia-compromised phagocytic functions in cultured macrophages, RAW 264.7 cells, and primary bone marrow-derived macrophages. Similarly, GAT107 (3.3 µM) also attenuated oxidative stress in hyperoxia-exposed macrophages, which prevents oxidation and hyper-polymerization of phagosome filamentous actin (F-actin) from oxidation. Furthermore, GAT107 (3.3 µM) increases the (1) activity of superoxide dismutase 1; (2) activation of Nrf2 and (3) the expression of heme oxygenase-1 (HO-1) in macrophages exposed to hyperoxia. Overall, these data suggest that the novel α7nAChR compound, GAT107, could be used to improve host defense functions in patients, such as those with COVID-19, who are exposed to prolonged periods of hyperoxia.