Impaired flow-mediated dilation in hospitalized patients with community-acquired pneumonia

Hypoalbuminemia as predictor of thrombotic events in patients with community-acquired pneumonia

BACKGROUND

Hypoalbuminemia complicates acute diseases and infections and is associated with a worst prognosis. The aim is to evaluate whether hypoalbuminemia is associated with higher incidence and risk of thrombotic events in community-acquired pneumonia.

METHODS

We retrospectively collected data from a prospective study investigating the incidence of thrombotic events in community-acquired pneumonia hospitalized patients from 2011 to 2016 at University-Hospital Policlinico Umberto I. Baseline characteristics and outcomes were collected. Incidence of outcomes were calculated. Kaplan-Meier curves were created, Cox model used to identify predictors for the outcomes, and competing risk analysis performed.

RESULTS

From a total of 231 patients, 130 (56.3%) and 101 (43.7%) had or not hypoalbuminemia. Age, proportion of female, BMI, major comorbidities, and severity of pneumonia were similar between two subgroups. A less proportion of patients with hypoalbuminemia received antithrombotic and statin therapy. Median hospital stay was 11 days in both subgroups. Patients with hypoalbuminemia had higher D-dimer and high- sensitivity C-reactive-protein values with an inverse relation between albumin values and these markers. Incidence of thrombotic events was 26 and 11 per 1000 patient-days in patient with and without hypoalbuminemia. At Cox model, hypoalbuminemia was associated with thrombotic events development in univariable (hazard ratio; 2.67, 95% confidence intervals, 1.30-5.40) and multivariable (hazard ratio 3.19; 95% confidence intervals, 1.48-6.89) analysis.

CONCLUSIONS

More than a half of patients with community acquired pneumonia had hypoalbuminemia that is associated with a doubled incidence and a three-fold increased risk of thrombotic events. The inverse relation between baseline albumin and D-dimer values confirms this association.

Recovery of Endothelium-dependent vascular relaxation impairment in convalescent COVID-19 patients: Insight from a pilot study

BACKGROUND

Endothelial dysfunction is a key-feature in acute COVID-19. However, follow-up data regarding endothelial dysfunction and injury after COVID-19 infection are lacking. We aimed to investigate the changes in endothelium-dependent vasorelaxation at baseline and four months after hospital discharge in COVID-19 patients.

METHODS

Twenty COVID-19 patients were compared to 24 healthy controls. Clinical and morphological data were collected after hospital admission for SARS-CoV-2 infection and reactive hyperaemia index (RHI) measurement was performed with a delay between 24 and 48 h after hospital admission and four months after hospital discharge in the outpatient clinics. Blood tests including inflammatory markers and measurement of post-occlusive vasorelaxation by digital peripheral arterial tonometry were performed at both visits.

RESULTS

At baseline, COVID-19 patients exhibited reduced RHI compared to controls (p < 0.001), in line with an endothelial dysfunction. At four months follow-up, there was a 51% increase in the RHI (1.69 ± 0.32 to 2.51 ± 0.91; p < 0.01) in favor of endothelium-dependent vascular relaxation recovery. RHI changes were positively correlated with baseline C-reactive protein (r = 0.68; p = 0.02). Compared to COVID-19 patients with a decrease in RHI, COVID-19 patients with an increase in RHI beyond the day-to-day variability (i.e. >11%) had less severe systemic inflammation at baseline.

CONCLUSION

Convalescent COVID-19 patients showed a recovery of systemic artery endothelial dysfunction, in particular patients with lower inflammation at baseline. Further studies are needed to decipher the interplay between inflammation and endothelial dysfunction in COVID-19 patients.

Endothelial dysfunction, oxidative stress and low-grade endotoxemia in COVID-19 patients hospitalised in medical wards

BACKGROUND

Endothelial dysfunction, assessed by flow-mediated dilation (FMD), is related to poor prognosis in patients with COVID-19 pneumonia (CP). In this study, we explored the interplay among FMD, NADPH oxidase type 2 (NOX-2) and lipopolysaccharides (LPS) in hospitalised patients with CP, community acquired pneumonia (CAP) and controls (CT).

METHODS

We enrolled 20 consecutive patients with CP, 20 hospitalised patients with CAP and 20 CT matched for sex, age, and main cardiovascular risk factors. In all subjects we performed FMD and collected blood samples to analyse markers of oxidative stress (soluble Nox2-derived peptide (sNOX2-dp), hydrogen peroxide breakdown activity (HBA), nitric oxide (NO), hydrogen peroxide (H2O2)), inflammation (TNF-α and IL-6), LPS and zonulin levels.

RESULTS

Compared with controls, CP had significant higher values of LPS, sNOX-2-dp, H2O2,TNF-α, IL-6 and zonulin; conversely FMD, HBA and NO bioavailability were significantly lower in CP. Compared to CAP patients, CP had significantly higher levels of sNOX2-dp, H2O2, TNF-α, IL-6, LPS, zonulin and lower HBA. Simple linear regression analysis showed that FMD inversely correlated with sNOX2-dp, H2O2, TNF-α, IL-6, LPS and zonulin; conversely FMD was directly correlated with NO bioavailability and HBA. Multiple linear regression analysis highlighted LPS as the only predictor of FMD.

CONCLUSION

This study shows that patients with COVID-19 have low-grade endotoxemia that could activate NOX-2, generating increased oxidative stress and endothelial dysfunction.

Carotid intima-media thickness and flow-mediated dilation do not predict acute in-hospital outcomes in hospitalized patients with COVID-19

Studies have suggested a potential role of endothelial dysfunction and atherosclerosis in the pathophysiology of COVID-19. Herein we tested whether brachial flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) measured upon hospital admission are associated with acute in-hospital outcomes in hospitalized COVID-19 patients. A total of 211 hospitalized patients with COVID-19 were submitted to assessments of FMD and mean and maximum cIMT (cIMT_mean and cIMT_max) within the first 72 hours of hospital admission. Study primary outcome was a composite of intensive care unit admission, mechanical ventilation, or death during the hospitalization. These outcomes were also considered independently. Thrombotic events were included as a secondary outcome. Odds ratios (OR) and confidence intervals (CI) were calculated using unadjusted and adjusted multivariable logistic regression models. Eighty-eight (42%) participants demonstrated at least one of the composite outcomes. cIMT_mean and cIMT_max were predictors of mortality and thrombotic events in the univariate analysis (cIMT_mean and mortality: unadjusted OR 13.0[95%CI 1.7-105], P=0.015; cIMT_mean and thrombotic events: unadjusted OR 13.0[95%CI 1.7-93]; P=0.013; cIMT_max and mortality: unadjusted OR 8.3[95%CI 1.3-53]; P=0.026; cIMT_max and thrombotic events: unadjusted OR 12.0[95%CI 2.0-74]; P=0.007). However, these associations were no longer present after adjustment for potential confounders (P=0.06-0.79). Additionally, FMD% was not associated with any outcome. In conclusion, cIMT and FMD are not independent predictors of clinical outcomes in hospitalized patients with COVID-19. These results suggest that subclinical atherosclerosis and endothelial dysfunction may not be the main drivers of COVID-19 complications in hospitalized COVID-19 patients.

Diet Supplementation, Probiotics, and Nutraceuticals in SARS-CoV-2 Infection: A Scoping Review

The severe acute respiratory syndrome coronavirus 2 (Sars-CoV-2) global pandemic is a devastating event that is causing thousands of victims every day around the world. One of the main reasons of the great impact of coronavirus disease 2019 (COVID-19) on society is its unexpected spread, which has not allowed an adequate preparation. The scientific community is fighting against time for the production of a vaccine, but it is difficult to place a safe and effective product on the market as fast as the virus is spreading. Similarly, for drugs that can directly interfere with viral pathways, their production times are long, despite the great efforts made. For these reasons, we analyzed the possible role of non-pharmacological substances such as supplements, probiotics, and nutraceuticals in reducing the risk of Sars-CoV-2 infection or mitigating the symptoms of COVID-19. These substances could have numerous advantages in the current circumstances, are generally easily available, and have negligible side effects if administered at the already used and tested dosages. Large scientific evidence supports the benefits that some bacterial and molecular products may exert on the immune response to respiratory viruses. These could also have a regulatory role in systemic inflammation or endothelial damage, which are two crucial aspects of COVID-19. However, there are no specific data available, and rigorous clinical trials should be conducted to confirm the putative benefits of diet supplementation, probiotics, and nutraceuticals in the current pandemic.

Hypercoagulation and Antithrombotic Treatment in Coronavirus 2019: A New Challenge

The novel coronavirus 2019 (COVID-19) is clinically characterized by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is responsible for a high number of patients needing mechanical ventilation or intensive care units treatment and for the elevated mortality risk. A link between COVID-19 and multiorgan failure may be dependent on the fact that most COVID-19 patients are complicated by pneumonia, which is known to be associated with early changes of clotting and platelet activation and artery dysfunction; these changes may implicate in thrombotic-related events such as myocardial infarction and ischemic stroke. Recent data showed that myocardial injury compatible with coronary ischemia may be detectable in SARS-CoV-2 patients and laboratory data exploring clotting system suggest the presence of a hypercoagulation state. Thus, we performed a systematic review of COVID-19 literature reporting measures of clotting activation to assess if changes are detectable in this setting and their relationship with clinical severity. Furthermore, we discussed the biologic plausibility of the thrombotic risk in SARS-CoV-2 and the potential use of an antithrombotic treatment.

Corticosteroid Use and Incident Myocardial Infarction in Adults Hospitalized for Community-acquired Pneumonia

RATIONALE

Adults hospitalized for community-acquired pneumonia (CAP) have an increased risk of myocardial infarction. Corticosteroid treatment lowers CAP morbidity and mortality, but it is not known whether it influences in-hospital myocardial infarction.

OBJECTIVES

The aim of the present study was to investigate the potential interplay between corticosteroid treatment and in-hospital myocardial infarction in adults with CAP.

METHODS

We retrospectively analyzed adults with CAP referred to the University Hospital Policlinico Umberto I (Rome, Italy), consecutively recruited, and prospectively followed until discharge. The primary outcome was the occurrence of myocardial infarction during hospitalization. We used propensity score-adjusted Cox models to examine the association between corticosteroid use and myocardial infarction.

RESULTS

Seven hundred fifty-eight patients (493 males, 265 females; mean ± standard deviation age, 71.7 ± 14.4 yr) were included in the study. Of these, 241 (32%) were treated with systemic corticosteroids (methylprednisolone, betamethasone, or prednisone). During follow-up, 62 (8.2%) had a myocardial infarction during their hospitalization (incidence, 0.72 per 100 person-days; 95% confidence interval [CI], 0.55 to 0.92). Those treated with corticosteroids had a lower incidence of myocardial infarction (0.42 per 100 person-days) than those not treated with corticosteroids (0.89 per 100 person-days; absolute rate difference, -0.48 per 100 person-days; 95% CI, -0.85 to -0.10). In a propensity score-adjusted Cox model, corticosteroid use was associated with a lower incidence of myocardial infarction (hazard ratio, 0.46; 95% CI, 0.24 to 0.88; P = 0.02).

CONCLUSIONS

We found that in-hospital corticosteroid treatment was associated with a lower incidence of myocardial infarction in adults hospitalized with CAP.

Fisiopatología de la enfermedad cardiovascular en pacientes con COVID-19. Isquemia, trombosis y disfunción cardiaca

Las complicaciones cardiovasculares tienen una alta prevalencia en los pacientes con COVID-19 y son motivo frecuente de hospitalización, mortalidad y secuelas. En está revisión se describen los principales mecanismos fisiopatológicos implicados en la aparición de estas complicaciones. Tras la viremia inicial, se produce una infiltración y reproducción en los pulmónes, con activación del sistema inmunitario, liberación de citocinas y generación de un estado proinflamatorio con sepsis y fallo multiorgánico. El daño miocárdico puede deberse a una afección viral directa con respuesta inflamatoria local, o indirectamente a una inflamación sistémica inapropiada con marcada liberación de citocinas. Además, se genera un estado protrombótico que, junto con la afección viral vascular, pueden desencadenar eventos trombóticos e isquémicos secundarios a daño microvascular o inestabilización de placas de ateroma previas. Son necesarios nuevos estudios para esclarecer la fisiopatología tras estos eventos cardiovasculares y contribuir al desarrollo de nuevos tratamientos efectivos.

Vitamin C deficiency in Australian hospitalised patients: an observational study

BACKGROUND

Vitamin C has anti-oxidant properties and acts as a cofactor for several enzymes. Hypovitaminosis C has been associated with bleeding, endothelial dysfunction and death. The prevalence of hypovitaminosis C is unknown in Australian hospitalised patients, and its clinical relevance is uncertain.

AIMS

To determine the prevalence, characteristics and clinical outcomes of hospitalised patients with hypovitaminosis C.

METHODS

This observational study included general-medical inpatients in a tertiary-level hospital in Australia. High-performance liquid chromatography (HPLC) was used to determine plasma vitamin C levels. As per Johnston's criteria, vitamin C levels of ≥28 μmol/L were classified as normal and <28 μmol/L as low. Clinical outcomes determined included length of hospital stay (LOS), nosocomial complications, intensive care unit admission and in-hospital mortality.

RESULTS

A total of 200 patients participated in this study, and vitamin C levels were available for 149 patients, of whom 35 (23.5%) had normal vitamin C levels, and 114 (76.5%) had hypovitaminosis C. Patients with hypovitaminosis C were older and had higher C-reactive protein (CRP) levels. Median LOS was 2 days longer in patients with hypovitaminosis C (6 days (interquartile range (IQR) 4, 8) vs 4 days (IQR 3, 6), P = 0.02), and they had fourfold higher odds of staying in hospital for >5 days than those with normal vitamin C levels. Other clinical outcomes were similar between the two groups.

CONCLUSIONS

Hypovitaminosis C is common in hospitalised patients and is associated with prolonged LOS. Further research is needed to ascertain the benefits of vitamin C supplementation in vitamin C-depleted patients.

Fatal community-acquired Bacillus cereus pneumonia in an immunocompetent adult man: a case report

BACKGROUND

Bacillus cereus is a gram-positive rod bacterium that is responsible for food poisoning. It is naturally widely distributed, and thus often contaminates cultures. Although it is rarely considered responsible, it can cause serious infections under certain conditions. However, lethal infections, especially in immunocompetent patients, are rare.

CASE PRESENTATION

A healthy 60-year-old man developed community-acquired B. cereus pneumonia and alveolar hemorrhage unveiled by abrupt chest pain and hemoptysis with no other advance symptoms. B. cereus induced silent alveolar destruction without any local or systemic inflammatory response. Although the lesion resembled lung anthrax, there was no evidence of Bacillus anthracis toxin.

CONCLUSIONS

Some isolates of B. cereus can cause anthrax-like fulminant necrotizing pneumonia in immunocompetent patients. If this type of B. cereus were used as a means of bioterrorism, it may be quite difficult to recognize as bioterrorism. We should keep B. cereus in mind as a potential pathogen of fulminant human infectious disease.

Isoprostanes, neuroprostanes and phytoprostanes: An overview of 25years of research in chemistry and biology

Since the beginning of the 1990's diverse types of metabolites originating from polyunsaturated fatty acids, formed under autooxidative conditions were discovered. Known as prostaglandin isomers (or isoprostanoids) originating from arachidonic acid, neuroprostanes from docosahexaenoic acid, and phytoprostanes from α-linolenic acid proved to be prevalent in biology. The syntheses of these compounds by organic chemists and the development of sophisticated mass spectrometry methods has boosted our understanding of the isoprostanoid biology. In recent years, it has become accepted that these molecules not only serve as markers of oxidative damage but also exhibit a wide range of bioactivities. In addition, isoprostanoids have emerged as indicators of oxidative stress in humans and their environment. This review explores in detail the isoprostanoid chemistry and biology that has been achieved in the past three decades.

Lipopolysaccharide as trigger of platelet aggregation via eicosanoid over-production

The effect of lipopolysaccharide (LPS) on platelet aggregation is still controversial. We performed in vitro and ex vivo studies in controls and in patients with community-acquired pneumonia (CAP) to assess the effect of LPS on platelet activation (PA). LPS (15-100 pg/ml) significantly increased PA only if combined with sub-threshold concentrations (STC) of collagen or ADP; this effect was associated with increased platelet H₂O₂ production, Nox2 activation, PLA2 phosphorylation, thromboxane (Tx)A₂ and 8-iso-PGF2α-III, and was inhibited by aspirin, TxA2 receptor antagonist or by Toll-like receptor 4 blocking peptide (TLR4bp). Analysis of up-stream signalling potentially responsible for Nox2 and PLA2 activation demonstrated that LPS-mediated PA was associated with phosphorylation of AKT, p38 and p47phox translocation. In 10 consecutive CAP patients serum endotoxins were significantly higher compared to 10 controls (145 [115-187] vs 18 [6-21] pg/ml; p<0.01). Ex vivo study showed that agonist-stimulated platelets were associated with enhanced PA (p<0.01), Toll-like receptor 4 (TLR4) expression (p<0.05), TxA₂ (p<0.01) and 8-iso-PGF2α-III (p<0.01) production in CAP patients compared to controls. The study provides evidence that LPS amplifies the platelet response to common agonists via TLR4-mediated eicosanoid production and suggests LPS as a potential trigger for PA in CAP.