Association between PaO2/FiO2 ratio and thrombotic events in COVID-19 patients.

PaO2/FiO2 (P/F ratio) is considered a marker of hypoxia/hypoxemia and mortality. Several prothrombotic changes are associated with the decrease of P/F ratio. The role of P/F ratio in patients with arterial and venous thrombosis remains unclear. The aim of this study was to assess in patients with coronavirus disease 2019 (COVID-19), the association between P/F ratio and arterial/venous thrombosis. One thousand and four hundred and six COVID-19 patients were recruited; 289 (21%) patients had P/F ratio < 200 and 1117 (79%) ≥ 200. Compared to the patients with P/F ratio ≥ 200, those with P/F ratio < 200 were older and with higher levels of glycemia, D-dimer and lower levels of albumin. Multiple linear regression analysis showed that albumin (standardized coefficient ß:  0.156; SE: 0.001; p = 0.0001) and D-dimer (standardized coefficient ß: -0.135; SE: 0.0001; p = 0.0001) were associated with P/F ratio. During the hospitalization 159 patients were transferred in intensive care unit (ICU), 253 patients died, 156 patients had arterial or venous thrombotic events. A bivariate logistic analysis was performed to analyze the predictors of thrombosis in COVID-19 patients; P/F ratio < 200 (Odds Ratio: [OR] 1.718, 95% Confidence Interval [CI] 1.085-2.718, p = 0.021), albumin (OR 1.693, 95% CI 1.055-2.716, p = 0.029), D-dimer (OR 3.469, 95% CI 2.110-5.703, p < 0.0001), coronary artery disease (CAD) (OR 1.800, 95% CI 1.086-2.984, p = 0.023) and heart failure (OR 2.410 95% CI 1.385-4.193, p = 0.002) independently predicted thrombotic events in this population. This study suggests that the P/F ratio is associated with thrombotic events by promoting a hypercoagulation state in patients hospitalized for COVID-19.

Infection prevention and control programme and COVID-19 measures: Effects on hospital-acquired infections in patients with cirrhosis.

Background & Aims: Bacterial infections affect survival of patients with cirrhosis. Hospital-acquired bacterial infections present a growing healthcare problem because of the increasing prevalence of multidrug-resistant organisms. This study aimed to investigate the impact of an infection prevention and control programme and coronavirus disease 2019 (COVID-19) measures on the incidence of hospital-acquired infections and a set of secondary outcomes, including the prevalence of multidrug-resistant organisms, empiric antibiotic treatment failure, and development of septic states in patients with cirrhosis. Methods: The infection prevention and control programme was a complex strategy based on antimicrobial stewardship and the reduction of patient's exposure to risk factors. The COVID-19 measures presented further behavioural and hygiene restrictions imposed by the Hospital and Health Italian Sanitary System recommendations. We performed a combined retrospective and prospective study in which we compared the impact of extra measures against the hospital standard. Results: We analysed data from 941 patients. The infection prevention and control programme was associated with a reduction in the incidence of hospital-acquired infections (17 vs. 8.9%, p <0.01). No further reduction was present after the COVID-19 measures had been imposed. The impact of the infection prevention and control programme remained significant even after controlling for the effects of confounding variables (odds ratio 0.44, 95% CI 0.26-0.73, p = 0.002). Furthermore, the adoption of the programme reduced the prevalence of multidrug-resistant organisms and decreased rates of empiric antibiotic treatment failure and the development of septic states. Conclusions: The infection prevention and control programme decreased the incidence of hospital-acquired infections by nearly 50%. Furthermore, the programme also reduced the prevalence of most of the secondary outcomes. Based on the results of this study, we encourage other liver centres to adopt infection prevention and control programmes. Impact and implications: Infections are a life-threatening problem for patients with liver cirrhosis. Moreover, hospital-acquired infections are even more alarming owing to the high prevalence of multidrug-resistant bacteria. This study analysed a large cohort of hospitalised patients with cirrhosis from three different periods. Unlike in the first period, an infection prevention programme was applied in the second period, reducing the number of hospital-acquired infections and containing multidrug-resistant bacteria. In the third period, we imposed even more stringent measures to minimise the impact of the COVID-19 outbreak. However, these measures did not result in a further reduction in hospital-acquired infections.

Increased Von Willebrand factor platelet-binding capacity is related to poor prognosis in COVID-19 patients.

None.

Toll-Like Receptor 4-Dependent Platelet-Related Thrombosis in SARS-CoV-2 Infection.

BACKGROUND: SARS-CoV-2 is associated with an increased risk of venous and arterial thrombosis, but the underlying mechanism is still unclear. METHODS: We performed a cross-sectional analysis of platelet function in 25 SARS-CoV-2 and 10 healthy subjects by measuring Nox2 (NADPH oxidase 2)-derived oxidative stress and thromboxane B2, and investigated if administration of monoclonal antibodies against the S protein (Spike protein) of SARS-CoV-2 affects platelet activation. Furthermore, we investigated in vitro if the S protein of SARS-CoV-2 or plasma from SARS-CoV-2 enhanced platelet activation. RESULTS: Ex vivo studies showed enhanced platelet Nox2-derived oxidative stress and thromboxane B2 biosynthesis and under laminar flow platelet-dependent thrombus growth in SARS-CoV-2 compared with controls; both effects were lowered by Nox2 and TLR4 (Toll-like receptor 4) inhibitors. Two hours after administration of monoclonal antibodies, a significant inhibition of platelet activation was observed in patients with SARS-CoV-2 compared with untreated ones. In vitro study showed that S protein per se did not elicit platelet activation but amplified the platelet response to subthreshold concentrations of agonists and functionally interacted with platelet TLR4. A docking simulation analysis suggested that TLR4 binds to S protein via three receptor-binding domains; furthermore, immunoprecipitation and immunofluorescence showed S protein-TLR4 colocalization in platelets from SARS-CoV-2. Plasma from patients with SARS-CoV-2 enhanced platelet activation and Nox2-related oxidative stress, an effect blunted by TNF (tumor necrosis factor) α inhibitor; this effect was recapitulated by an in vitro study documenting that TNFα alone promoted platelet activation and amplified the platelet response to S protein via p47phox (phagocyte oxidase) upregulation. CONCLUSIONS: The study identifies 2 TLR4-dependent and independent pathways promoting platelet-dependent thrombus growth and suggests inhibition of TLR4. or p47phox as a tool to counteract thrombosis in SARS-CoV-2.

Association between PaO2/FiO2 ratio and thrombotic events in COVID-19 patients.

PaO2/FiO2 (P/F ratio) is considered a marker of hypoxia/hypoxemia and mortality. Several prothrombotic changes are associated with the decrease of P/F ratio. The role of P/F ratio in patients with arterial and venous thrombosis remains unclear. The aim of this study was to assess in patients with coronavirus disease 2019 (COVID-19), the association between P/F ratio and arterial/venous thrombosis. One thousand and four hundred and six COVID-19 patients were recruited; 289 (21%) patients had P/F ratio < 200 and 1117 (79%) ≥ 200. Compared to the patients with P/F ratio ≥ 200, those with P/F ratio < 200 were older and with higher levels of glycemia, D-dimer and lower levels of albumin. Multiple linear regression analysis showed that albumin (standardized coefficient ß:  0.156; SE: 0.001; p = 0.0001) and D-dimer (standardized coefficient ß: -0.135; SE: 0.0001; p = 0.0001) were associated with P/F ratio. During the hospitalization 159 patients were transferred in intensive care unit (ICU), 253 patients died, 156 patients had arterial or venous thrombotic events. A bivariate logistic analysis was performed to analyze the predictors of thrombosis in COVID-19 patients; P/F ratio < 200 (Odds Ratio: [OR] 1.718, 95% Confidence Interval [CI] 1.085-2.718, p = 0.021), albumin (OR 1.693, 95% CI 1.055-2.716, p = 0.029), D-dimer (OR 3.469, 95% CI 2.110-5.703, p < 0.0001), coronary artery disease (CAD) (OR 1.800, 95% CI 1.086-2.984, p = 0.023) and heart failure (OR 2.410 95% CI 1.385-4.193, p = 0.002) independently predicted thrombotic events in this population. This study suggests that the P/F ratio is associated with thrombotic events by promoting a hypercoagulation state in patients hospitalized for COVID-19.

Health-related quality of life in survivors of severe COVID-19 infection.

BACKGROUND: Long-term effects of Coronavirus Disease 2019 (COVID-19) are increasingly recognized as having a significant impact on Health-Related Quality of Life (HRQoL). Understanding HRQoL status for each patient affected by long COVID-19 and its determinants may have a key role to prevent and treat this condition. METHODS: In this prospective observational study conducted in a large academic COVID-19 hospital in Rome, participants were contacted 2 years after hospital admission for severe COVID-19. To assess HRQoL, EQ-5D-5L and Visual analog scale (EQ VAS) standard questionnaires were administered by interview. Logistic regression model was used to the five health dimensions as dependent variables (0 = no problem, 1 = some/extreme problem). KEY RESULTS: In 137 enrolled patients, the mean pre-COVID and post-COVID EQ-5D-5L index and EQ-VAS score were 0.97 (SD 0.06), 0.79 (SD 0.26) and 72.38 (SD 15.18), respectively. After subdivision of the participants for clinical and social variables, the EQ-5D-5L index resulted significantly lower than in the pre-COVID-19 period. Female gender, unemployed status, and chronic comorbidities were the most common predictors for having any problems in each EQ-5D-5L domain, while also older age and higher Body Mass Index (BMI) showed to be related to a lower EQ-VAS score. CONCLUSION: HRQoL showed to be still low in patients 2 years after acute severe COVID-19. Given the significant impact of SARS-CoV-2 on long-term chronic symptoms, predictors of poor outcomes must be considered during the acute phase of illness to plan a tailored follow-up path for each patient.

Increased Von Willebrand factor platelet-binding capacity is related to poor prognosis in COVID-19 patients.

None.

Gut Microbiota and COVID-19: Potential Implications for Disease Severity.

The SARS-CoV-2 pandemic resulted in an unprecedented global crisis. SARS-CoV-2 primarily causes lung infection trough the binding of the virus with the ACE-2 cell receptor located on the surface of the alveolar epithelial cells. Notably, ACE-2 cell receptors are also expressed in the epithelial cells of the intestinal tract (GI). Recent data showed that the microbial communities of the GI might act as local and systematic inflammatory modulators. Gastrointestinal symptoms, including diarrhea, are frequently observed in infected individuals, and recent released data indicate that SARS-CoV-2 may also spread by fecal-oral transmission. Moreover, the gut microbiota's ecosystem can regulate and be regulated by invading pathogens, including viruses, facilitating an effective immune response, which in turn results in less severe diseases. In this regard, increased SARS-CoV-2 mortality and morbidities appear to be frequently observed in elderly immunocompromised patients and in people with essential health problems, such as diabetes, who, indeed, tend to have a less diverse gut microbiota (dysbiosis). Therefore, it is important to understand how the interaction between the gut microbiota and SARS-CoV-2 might shape the intensity of the infection and different clinical outcomes. Here, we provide insights into the current knowledge of dysbiosis during SARS-CoV-2 infection and methods that may be used to re-establish a more correct microbiota composition.

Comparison by Age of the Local Interferon Response to SARS-CoV-2 Suggests a Role for IFN-ε and -ω.

Children generally develop a mild disease after SARS-CoV-2 infection whereas older adults are at risk of developing severe COVID-19. Recent transcriptomic analysis showed pre-activated innate immunity in children, resulting in a more effective anti-SARS-CoV-2 response upon infection. To further characterize age-related differences, we studied type I and III interferon (IFN) response in SARS-CoV-2 infected and non-infected individuals of different ages. Specifically, levels of expression of type I (IFN-α, -ß, -ε and -ω), type III (IFN-λ1, -λ2 and -λ3) IFNs and of the IFN-stimulated genes, ISG15 and ISG56 were quantified in nasopharyngeal cells from diagnostic swabs. Basal transcription of type I/III IFN genes was highest among children and decreased with age. Among SARS-CoV-2-infected individuals, only IFN-ε and -ω levels were significantly higher in children and young adults whereas ISGs were overexpressed in infected adults. The occurrence of symptoms in children and the need for hospitalization in adults were associated to higher transcription of several IFN genes. Starting from a pre-activated transcription level, the expression of type I and III IFNs was not highly up-regulated in children upon SARS-CoV-2 infection; young adults activated IFNs' transcription at intermediate levels whereas older adults were characterized by higher ISGs and lower IFN-ε and -ω relative expression levels. Overall, our findings contribute to recognize components of a protective IFN response as a function of age, in the context of SARS-CoV-2 infection.

Superinfections caused by carbapenem-resistant Enterobacterales in hospitalized patients with COVID-19: a multicentre observational study from Italy (CREVID Study).

Objectives: To describe clinical characteristics and outcomes of COVID-19 patients who developed secondary infections due to carbapenem-resistant Enterobacterales (CRE). Methods: Retrospective observational study including COVID-19 patients admitted to 12 Italian hospitals from March to December 2020 who developed a superinfection by CRE. Superinfection was defined as the occurrence of documented bacterial infection >48 h from admission. Patients with polymicrobial infections were excluded. Demographic, clinical characteristics and outcome were collected. Isolates were classified as KPC, metallo-ß-lactamase (MBL) and OXA-48-producing CRE. A Cox regression analysis was performed to identify factors independently associated with 30 day mortality. Results: Overall, 123 patients (median age 66 years, IQR 59-75) were included. The majority of infections occurred in the ICU (81, 65.9%), while 42 (34.1%) in medical wards. The most common types of infection were bloodstream infections (BSI) (n = 64, 52%), followed by urinary-tract infections (UTI) (n = 28, 22.8%), hospital-acquired/ventilator-associated pneumonia (HAP/VAP) (n = 28, 22.8%), intra-abdominal infections (n = 2, 1.6%) and skin infections (n = 1, 0.8%). Sixty-three (51.2%) infections were caused by KPC-, 54 (43.9%) by MBL-, and 6 (4.8%) by OXA-48-producing CRE. Thirty-day mortality was 33.3% (41/123). On Cox regression analysis, HAP/VAP compared with UTI (HR 7.23, 95% CI 2.09-24.97, P = 0.004), BSI compared with UTI (HR 3.96, 95% CI, 1.33-11.77, P = 0.004), lymphopenia on admission (HR 3, 95% CI 1.44-6.26, P = 0.003) and age (HR 1.05, 95% CI 1.02-1.08, P = 0.002) were predictors of 30 day mortality. Conclusions: Superinfections by CRE were associated with high risk of 30 day mortality in patients with COVID-19. HAP/VAP was the strongest predictor of death in these patients.

Acinetobacter baumannii Isolates from COVID-19 Patients in a Hospital Intensive Care Unit: Molecular Typing and Risk Factors.

Infections caused by Acinetobacter baumannii represent a major concern for intensive care unit (ICU) patients. However, the epidemiology of these infections among COVID-19 patients has not been fully explored. The aims of this study were (i) to characterize the clonal spread of A. baumannii among COVID-19 patients admitted to the ICU of the Umberto I hospital of Rome during the first year of the pandemic and (ii) to identify risk factors for its acquisition. Isolates were analysed by pulsed-field gel electrophoresis, and a multivariable regression model was constructed. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated. Overall, 193 patients were included, and 102 strains were analysed. All isolates had highly antibiotic-resistant profiles and derived from two genotypes. The cumulative incidence of A. baumannii acquisition (colonization or infection) was 36.8%. Patients with A. baumannii had higher mortality and length of stay. Multivariable analysis showed that previous carbapenem use was the only risk factor associated with A. baumannii acquisition (aOR: 4.15, 95% CI: 1.78-9.64). We documented substantial A. baumannii infections and colonization and high levels of clonal transmission. Given the limited treatment options, effective prevention and containment strategies to limit the spread of A. baumannii should be implemented.

Oral Bacteriotherapy in Patients With COVID-19: A Retrospective Cohort Study.

Background: Mounting evidence suggests SARS-CoV-2 may impact on host microbiota and gut inflammation, infecting intestinal epithelial cells. This possible link and its implications can be investigated by observing the effects of modulation of the microbial flora in patients with COVID-19. The aim of this study was to compare the rate of mortality, the need of ICU hospitalization and the length of hospitalization in patients with severe COVID-19 pneumonia who received the best available therapy (BAT) vs. patients treated with BAT and supplemented with oral bacteriotherapy. Methods: This retrospective, observational cohort study included 200 adults with severe COVID-19 pneumonia. All patients received therapeutic regimens including low molecular weight heparin plus one or more between hydroxychloroquine, azithromycin, antivirals, and Tocilizumab. Oral bacteriotherapy was used as complementary treatment. Results: Out of the 200 patients, 112 received BAT without oral bacteriotherapy, and 88 BAT with oral bacteriotherapy. Crude mortality was 22%. Eleven percent died in the group of patients treated with BAT plus oral bacteriotherapy vs. 30% subjects in the group of patients managed only with BAT (p < 0.001). By multivariate analysis, the age >65 years, CRP >41.8 mg/L, Platelets <150.000 mmc, and cardiovascular events were associated with the increased risk of mortality. Oral bacteriotherapy was an independent variable associated with a reduced risk for death. Despite large prospective trials are needed, this study highlights a possible role for oral bacteriotherapy in the management of patients hospitalized for COVID-19 pneumonia.

Acute Kidney Injury and COVID-19: A Picture from an Intensive Care Unit.

INTRODUCTION: Acute kidney injury (AKI) is a frequent complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care unit (ICU) for severe respiratory failure. The aim is to evaluate the rate of AKI, defined according to Kidney Disease: Improving Global Outcome guidelines, in a series of critical COVID-19 patients admitted to the ICU of a single tertiary teaching hospital. METHODS: From April to May 2020, all consecutive critically ill COVID-19 patients admitted to the ICU who did not meet exclusion criteria (length of ICU stay <48 h, ESRD requiring dialysis, and patients still hospitalized in ICU at the time of data analysis) were enrolled in this study. Patients were stratified according to the highest AKI stage attained during ICU stay. RESULTS: Sixty-one patients were included in the analysis. AKI was observed in 35/61 patients (57.4%): 25/35 episodes (71.4%) were observed within the first 7 days. AKI was classified as follows: 17.1% stage 1, 25.7% stage 2, and 57.2% stage 3. Fourteen out of 20 stage-3 patients required continuous renal replacement therapy (CRRT), mostly related to persistent oliguria. The overall ICU mortality was 68.9%, and it was higher in patients developing AKI if compared to no-AKI patients (p = 0.006). Renal function recovery of any grade was observed in 14 out of 35 AKI patients (40%). Among patients undergoing CRRT, 13 patients were still dialysis dependent at the time of death. CONCLUSION: In critical COVID-19 patients, ICU mortality is particularly high, especially in patients developing AKI. An accurate monitoring of renal function in early phases of respiratory failure should be ensured in order to timely apply any strategy aimed at limiting renal complications during ICU stay.

Von Willebrand factor with increased binding capacity is associated with reduced platelet aggregation but enhanced agglutination in COVID-19 patients: another COVID-19 paradox?

Patients with Coronavirus-associated disease-2019 (COVID-19) display alterations of the hemostatic system and the presence of a prothrombotic status frequently leading to vascular complications. However, the impact of COVID-19 on platelet activity, aggregation and agglutination still needs to be clarified. We measured total levels of von Willebrand factor (vWF) and vWF binding to the platelet glycoprotein (Gp) complex (GPIb-IX-V), in a cohort of COVID-19 patients admitted to the intensive care unit of our Institution. Moreover, we evaluated platelet aggregation in response to agonists (ADP, collagen, arachidonic acid) and platelet agglutination in response to ristocetin. We found that levels of vWF antigen and the active form of vWF binding to platelets (vWF:RCo), were markedly increased in these patients. These results were associated with higher agglutination rates induced by ristocetin, thereby indirectly indicating an increased capability of vWF to bind to platelets. Conversely, we found that platelet aggregation in response to both ADP and collagen was lower in COVID-19 patients compared to healthy volunteers. This study shows that COVID-19 is associated with increased vWF-induced platelet agglutination but reduced platelet responsivity to aggregation stimuli. Our findings have translational relevance since platelet adhesion to vWF may represent a marker to predict possible complications and better delineate therapeutic strategies in COVID-19 patients.