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1.
Curr Issues Mol Biol ; 44(5): 2122-2138, 2022 May 10.
Article in English | MEDLINE | ID: covidwho-1869490

ABSTRACT

Neutrophils play a pathogenic role in COVID-19 by releasing Neutrophils Extracellular Traps (NETs) or human neutrophil elastase (HNE). Given that HNE is inhibited by α1-antitrypsin (AAT), we aimed to assess the content of HNE, α1-antitrypsin (AAT) and HNE-AAT complexes (the AAT/HNE balance) in 33 bronchoalveolar lavage fluid (BALf) samples from COVID-19 patients. These samples were submitted for Gel-Electrophoresis, Western Blot and ELISA, and proteins (bound to AAT or HNE) were identified by Liquid Chromatography-Mass Spectrometry. NETs' release was analyzed by confocal microscopy. Both HNE and AAT were clearly detectable in BALf at high levels. Contrary to what was previously observed in other settings, the formation of HNE-AAT complex was not detected in COVID-19. Rather, HNE was found to be bound to acute phase proteins, histones and C3. Due to the relevant role of NETs, we assessed the ability of free AAT to bind to histones. While confirming this binding, AAT was not able to inhibit NET formation. In conclusion, despite the finding of a high burden of free and bound HNE, the lack of the HNE-AAT inhibitory complex in COVID-19 BALf demonstrates that AAT is not able to block HNE activity. Furthermore, while binding to histones, AAT does not prevent NET formation nor their noxious activity.

2.
Crit Care Med ; 50(5): 723-732, 2022 05 01.
Article in English | MEDLINE | ID: covidwho-1706638

ABSTRACT

OBJECTIVES: Prone positioning allows to improve oxygenation and decrease mortality rate in COVID-19-associated acute respiratory distress syndrome (C-ARDS). However, the mechanisms leading to these effects are not fully understood. The aim of this study is to assess the physiologic effects of pronation by the means of CT scan and electrical impedance tomography (EIT). DESIGN: Experimental, physiologic study. SETTING: Patients were enrolled from October 2020 to March 2021 in an Italian dedicated COVID-19 ICU. PATIENTS: Twenty-one intubated patients with moderate or severe C-ARDS. INTERVENTIONS: First, patients were transported to the CT scan facility, and image acquisition was performed in prone, then supine position. Back to the ICU, gas exchange, respiratory mechanics, and ventilation and perfusion EIT-based analysis were provided toward the end of two 30 minutes steps (e.g., in supine, then prone position). MEASUREMENTS AND MAIN RESULTS: Prone position induced recruitment in the dorsal part of the lungs (12.5% ± 8.0%; p < 0.001 from baseline) and derecruitment in the ventral regions (-6.9% ± 5.2%; p < 0.001). These changes led to a global increase in recruitment (6.0% ± 6.7%; p < 0.001). Respiratory system compliance did not change with prone position (45 ± 15 vs 45 ± 18 mL/cm H2O in supine and prone position, respectively; p = 0.957) suggesting a decrease in atelectrauma. This hypothesis was supported by the decrease of a time-impedance curve concavity index designed as a surrogate for atelectrauma (1.41 ± 0.16 vs 1.30 ± 0.16; p = 0.001). Dead space measured by EIT was reduced in the ventral regions of the lungs, and the dead-space/shunt ratio decreased significantly (5.1 [2.3-23.4] vs 4.3 [0.7-6.8]; p = 0.035), showing an improvement in ventilation-perfusion matching. CONCLUSIONS: Several changes are associated with prone position in C-ARDS: increased lung recruitment, decreased atelectrauma, and improved ventilation-perfusion matching. These physiologic effects may be associated with more protective ventilation.


Subject(s)
COVID-19 , Respiratory Distress Syndrome , Electric Impedance , Humans , Lung/diagnostic imaging , Perfusion , Positive-Pressure Respiration/methods , Prone Position , Respiratory Distress Syndrome/diagnostic imaging , Respiratory Distress Syndrome/therapy , Tomography, X-Ray Computed
3.
Crit Care ; 25(1): 423, 2021 12 13.
Article in English | MEDLINE | ID: covidwho-1571913

ABSTRACT

BACKGROUND: Autoptic pulmonary findings have been described in severe COVID-19 patients, but evidence regarding the correlation between clinical picture and lung histopathologic patterns is still weak. METHODS: This was a retrospective cohort observational study conducted at the referral center for infectious diseases in northern Italy. Full lung autoptic findings and clinical data of patients who died from COVID-19 were analyzed. Lung histopathologic patterns were scored according to the extent of tissue damage. To consider coexisting histopathologic patterns, hierarchical clustering of histopathologic findings was applied. RESULTS: Whole pulmonary examination was available in 75 out of 92 full autopsies. Forty-eight hospitalized patients (64%), 44 from ICU and four from the medical ward, had complete clinical data. The histopathologic patterns had a time-dependent distribution with considerable overlap among patterns. Duration of positive-pressure ventilation (p < 0.0001), mean positive end-expiratory pressure (PEEP) (p = 0.007), worst serum albumin (p = 0.017), interleukin 6 (p = 0.047), and kidney SOFA (p = 0.001) differed among histopathologic clusters. The amount of PEEP for long-lasting ventilatory treatment was associated with the cluster showing the largest areas of early and late proliferative diffuse alveolar damage. No pharmacologic interventions or comorbidities affected the lung histopathology. CONCLUSIONS: Our study draws a comprehensive link between the clinical and pulmonary histopathologic findings in a large cohort of COVID-19 patients. These results highlight that the positive end-expiratory pressures and the duration of the ventilatory treatment correlate with lung histopathologic patterns, providing new clues to the knowledge of the pathophysiology of severe SARS-CoV-2 pneumonia.


Subject(s)
COVID-19 , Lung , Autopsy , Humans , Lung/pathology , Patient Acuity , Retrospective Studies
4.
Cell ; 184(19): 4953-4968.e16, 2021 09 16.
Article in English | MEDLINE | ID: covidwho-1363913

ABSTRACT

Severe coronavirus disease 2019 (COVID-19) is characterized by overproduction of immune mediators, but the role of interferons (IFNs) of the type I (IFN-I) or type III (IFN-III) families remains debated. We scrutinized the production of IFNs along the respiratory tract of COVID-19 patients and found that high levels of IFN-III, and to a lesser extent IFN-I, characterize the upper airways of patients with high viral burden but reduced disease risk or severity. Production of specific IFN-III, but not IFN-I, members denotes patients with a mild pathology and efficiently drives the transcription of genes that protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In contrast, compared to subjects with other infectious or noninfectious lung pathologies, IFNs are overrepresented in the lower airways of patients with severe COVID-19 that exhibit gene pathways associated with increased apoptosis and decreased proliferation. Our data demonstrate a dynamic production of IFNs in SARS-CoV-2-infected patients and show IFNs play opposing roles at distinct anatomical sites.


Subject(s)
COVID-19/pathology , Interferons/metabolism , Respiratory System/virology , Severity of Illness Index , Age Factors , Aging/pathology , COVID-19/genetics , COVID-19/immunology , Epithelial Cells/pathology , Epithelial Cells/virology , Gene Expression Regulation , Humans , Interferons/genetics , Leukocytes/pathology , Leukocytes/virology , Lung/pathology , Lung/virology , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , Viral Load
5.
Front Immunol ; 12: 663303, 2021.
Article in English | MEDLINE | ID: covidwho-1291384

ABSTRACT

The release of neutrophil extracellular traps (NETs), a process termed NETosis, avoids pathogen spread but may cause tissue injury. NETs have been found in severe COVID-19 patients, but their role in disease development is still unknown. The aim of this study is to assess the capacity of NETs to drive epithelial-mesenchymal transition (EMT) of lung epithelial cells and to analyze the involvement of NETs in COVID-19. Bronchoalveolar lavage fluid of severe COVID-19 patients showed high concentration of NETs that correlates with neutrophils count; moreover, the analysis of lung tissues of COVID-19 deceased patients showed a subset of alveolar reactive pneumocytes with a co-expression of epithelial marker and a mesenchymal marker, confirming the induction of EMT mechanism after severe SARS-CoV2 infection. By airway in vitro models, cultivating A549 or 16HBE at air-liquid interface, adding alveolar macrophages (AM), neutrophils and SARS-CoV2, we demonstrated that to trigger a complete EMT expression pattern are necessary the induction of NETosis by SARS-CoV2 and the secretion of AM factors (TGF-ß, IL8 and IL1ß). All our results highlight the possible mechanism that can induce lung fibrosis after SARS-CoV2 infection.


Subject(s)
COVID-19/physiopathology , Epithelial-Mesenchymal Transition , Extracellular Traps/metabolism , Neutrophils/metabolism , Adult , Biopsy , Bronchoalveolar Lavage Fluid/cytology , COVID-19/complications , COVID-19/immunology , Cell Line , Epithelial Cells/pathology , Humans , Lung/pathology , Pulmonary Fibrosis/etiology , Pulmonary Fibrosis/metabolism
6.
J Nephrol ; 35(1): 99-111, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1281356

ABSTRACT

BACKGROUND: Acute kidney injury (AKI) in Covid-19 patients admitted to the intensive care unit (ICU) is common, and its severity may be associated with unfavorable outcomes. Severe Covid-19 fulfills the diagnostic criteria for acute respiratory distress syndrome (ARDS); however, it is unclear whether there is any relationship between ventilatory management and AKI development in Covid-19 ICU patients. PURPOSE: To describe the clinical course and outcomes of Covid-19 ICU patients, focusing on ventilatory management and factors associated with AKI development. METHODS: Single-center, retrospective observational study, which assessed AKI incidence in Covid-19 ICU patients divided by positive end expiratory pressure (PEEP) tertiles, with median levels of 9.6 (low), 12.0 (medium), and 14.7 cmH2O (high-PEEP). RESULTS: Overall mortality was 51.5%. AKI (KDIGO stage 2 or 3) occurred in 38% of 101 patients. Among the AKI patients, 19 (53%) required continuous renal replacement therapy (CRRT). In AKI patients, mortality was significantly higher versus non-AKI (81% vs. 33%, p < 0.0001). The incidence of AKI in low-, medium-, or high-PEEP patients were 16%, 38%, and 59%, respectively (p = 0.002). In a multivariate analysis, high-PEEP patients showed a higher risk of developing AKI than low-PEEP patients (OR = 4.96 [1.1-21.9] 95% CI p < 0.05). ICU mortality rate was higher in high-PEEP patients, compared to medium-PEEP or low-PEEP patients (69% vs. 44% and 42%, respectively; p = 0.057). CONCLUSION: The use of high PEEP in Covid-19 ICU patients is associated with a fivefold higher risk of AKI, leading to higher mortality. The cause and effect relationship needs further analysis.


Subject(s)
Acute Kidney Injury , COVID-19 , Acute Kidney Injury/diagnosis , Acute Kidney Injury/epidemiology , Acute Kidney Injury/therapy , Humans , Intensive Care Units , Positive-Pressure Respiration/adverse effects , SARS-CoV-2
7.
J Palliat Med ; 23(11): 1422-1423, 2020 11.
Article in English | MEDLINE | ID: covidwho-1160149

Subject(s)
COVID-19 , Pandemics , Humans , SARS-CoV-2
8.
BMC Pulm Med ; 20(1): 301, 2020 Nov 16.
Article in English | MEDLINE | ID: covidwho-925848

ABSTRACT

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapidly reached pandemic proportions. Given that the main target of SARS-CoV-2 are lungs leading to severe pneumonia with hyperactivation of the inflammatory cascade, we conducted a prospective study to assess alveolar inflammatory status in patients with moderate to severe COVID-19. METHODS: Diagnostic bronchoalveolar lavage (BAL) was performed in 33 adult patients with SARS-CoV-2 infection by real-time PCR on nasopharyngeal swab admitted to the Intensive care unit (ICU) (n = 28) and to the Intermediate Medicine Ward (IMW) (n = 5). We analyze the differential cell count, ultrastructure of cells and Interleukin (IL)6, 8 and 10 levels. RESULTS: ICU patients showed a marked increase in neutrophils (1.24 × 105 ml- 1, 0.85-2.07), lower lymphocyte (0.97 × 105 ml- 1, 0.024-0.34) and macrophages fractions (0.43 × 105 ml- 1, 0.34-1.62) compared to IMW patients (0.095 × 105 ml- 1, 0.05-0.73; 0.47 × 105 ml- 1, 0.28-1.01 and 2.14 × 105 ml- 1, 1.17-3.01, respectively) (p < 0.01). Study of ICU patients BAL by electron transmission microscopy showed viral particles inside mononuclear cells confirmed by immunostaining with anti-viral capsid and spike antibodies. IL6 and IL8 were significantly higher in ICU patients than in IMW (IL6 p < 0.01, IL8 p < 0.0001), and also in patients who did not survive (IL6 p < 0.05, IL8 p = 0.05 vs. survivors). IL10 did not show a significant variation between groups. Dividing patients by treatment received, lower BAL concentrations of IL6 were found in patients treated with steroids as compared to those treated with tocilizumab (p < 0.1) or antivirals (p < 0.05). CONCLUSIONS: Alveolitis, associated with COVID-19, is mainly sustained by innate effectors which showed features of extensive activation. The burden of pro-inflammatory cytokines IL6 and IL8 in the broncho-alveolar environment is associated with clinical outcome.


Subject(s)
Bronchoalveolar Lavage Fluid/immunology , Coronavirus Infections/immunology , Inflammation/immunology , Interleukin-6/immunology , Interleukin-8/immunology , Leukocytes/immunology , Lung/immunology , Macrophages, Alveolar/immunology , Pneumonia, Viral/immunology , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/therapeutic use , Adrenal Cortex Hormones/therapeutic use , Aged , Alanine/analogs & derivatives , Alanine/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Antiviral Agents/therapeutic use , Betacoronavirus , Bronchoalveolar Lavage , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/virology , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/therapy , Drug Combinations , Female , Humans , Hydroxychloroquine/therapeutic use , Intensive Care Units , Interleukin-10/immunology , Italy , Leukocytes, Mononuclear/virology , Lopinavir/therapeutic use , Lung/cytology , Lung/virology , Lymphocytes/immunology , Male , Microscopy, Electron, Transmission , Middle Aged , Neutrophils/immunology , Pandemics , Pneumonia, Viral/therapy , Prognosis , Prospective Studies , Respiration, Artificial/methods , Ritonavir/therapeutic use , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/metabolism , Survival Rate , Virion/metabolism , Virion/ultrastructure
10.
Eur J Intern Med ; 76: 36-42, 2020 06.
Article in English | MEDLINE | ID: covidwho-377283

ABSTRACT

BACKGROUND: Tocilizumab, a humanized monoclonal antibody, targets IL-6 receptors blocking downstream pro-inflammatory effects of IL-6. In preliminary reports it was suggested to be beneficial in patients with severe COVID-19. METHODS: In this open-label prospective study we describe clinical characteristics and outcome of 51 patients hospitalized with confirmed and severe COVID-19 pneumonia treated with tocilizumab intravenously. All patients had elevated IL-6 plasma level (>40 pg/mL) and oxygen saturation <93% in ambient air. Clinical outcomes, oxygen support, laboratory data and adverse events were collected over a follow-up of 30 days. RESULTS: Forty-five patients (88%) were on high-flow oxygen supplementation, six of whom with invasive ventilation. From baseline to day 7 after tocilizumab we observed a dramatic drop of body temperature and CRP value with a significant increase in lymphocyte count (p<0.001). Over a median follow-up time of 34 days from tocilizumab, 34 patients (67%) showed an improvement in their clinical severity class; 31 were discharged; 17 (33%) showed a worsening of their clinical status, of these 14 died (27%). The mortality rate was significantly associated with mechanical ventilation at baseline (83.3% vs 20% of patients on non-invasive oxygen support; p=0.0001). The most frequent side effects were an increase of hepatic enzymes (29%), thrombocytopenia (14%), and serious bacterial and fungal infections (27%). CONCLUSION: Tocilizumab exerts a rapidly beneficial effect on fever and inflammatory markers, although no significant impact on the clinical outcome can be inferred by our results. Critically ill patients seem to have a high risk of serious infections with this drug.


Subject(s)
Antibodies, Monoclonal, Humanized , Coronavirus Infections , Pandemics , Pneumonia, Viral , Receptors, Interleukin-6/antagonists & inhibitors , Respiration, Artificial/methods , Respiratory Insufficiency , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antiviral Agents/adverse effects , Betacoronavirus/drug effects , Betacoronavirus/isolation & purification , COVID-19 , Coronavirus Infections/blood , Coronavirus Infections/epidemiology , Coronavirus Infections/physiopathology , Coronavirus Infections/therapy , Female , Fever/diagnosis , Fever/drug therapy , Humans , Italy/epidemiology , Lymphocyte Count/methods , Male , Middle Aged , Outcome and Process Assessment, Health Care , Pneumonia, Viral/blood , Pneumonia, Viral/diagnosis , Pneumonia, Viral/drug therapy , Pneumonia, Viral/epidemiology , Pneumonia, Viral/etiology , Pneumonia, Viral/physiopathology , Pneumonia, Viral/therapy , Respiratory Insufficiency/etiology , Respiratory Insufficiency/therapy , Retrospective Studies , SARS-CoV-2
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