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1.
J Pathol ; 2021 Dec 03.
Article in English | MEDLINE | ID: covidwho-1549277

ABSTRACT

COVID-19 is a pandemic with high morbidity and mortality. In an autopsy cohort of COVID-19 patients, we found extensive accumulation of the tryptophan degradation products 3-hydroxy anthranilic acid and quinolinic acid in lungs, heart, and brain. This was not related to the expression of the tryptophan-catabolizing indoleamine 2,3-dioxygenase (IDO)-1, but rather to that of its isoform IDO-2, which otherwise is expressed rarely. Bioavailability of tryptophan is an absolute requirement for proper cell functioning and synthesis of hormones, whereas its degradation products can cause cell death. Markers of apoptosis and severe cellular stress were associated with IDO-2 expression in large areas of lung and heart tissue, whereas affected areas in brain were more restricted. Analyses of tissue, cerebrospinal fluid, and sequential plasma samples indicate early initiation of the kynurenine/aryl-hydrocarbon receptor/IDO-2 axis as a positive feedback loop, potentially leading to severe COVID-19 pathology. This article is protected by copyright. All rights reserved.

2.
Front Immunol ; 12: 697840, 2021.
Article in English | MEDLINE | ID: covidwho-1359188

ABSTRACT

Monocytes are antigen-presenting cells (APCs) that play diverse roles in promoting or regulating inflammatory responses, but their role in T cell stimulation is not well defined. In inflammatory conditions, monocytes frequently show increased expression of CD169/Siglec-1, a type-I interferon (IFN-I)-regulated protein. However, little is known about the phenotype and function of these CD169+ monocytes. Here, we have investigated the phenotype of human CD169+ monocytes in different diseases, their capacity to activate CD8+ T cells, and the potential for a targeted-vaccination approach. Using spectral flow cytometry, we detected CD169 expression by CD14+ CD16- classical and CD14+ CD16+ intermediate monocytes and unbiased analysis showed that they were distinct from dendritic cells, including the recently described CD14-expressing DC3. CD169+ monocytes expressed higher levels of co-stimulatory and HLA molecules, suggesting an increased activation state. IFNα treatment highly upregulated CD169 expression on CD14+ monocytes and boosted their capacity to cross-present antigen to CD8+ T cells. Furthermore, we observed CD169+ monocytes in virally-infected patients, including in the blood and bronchoalveolar lavage fluid of COVID-19 patients, as well as in the blood of patients with different types of cancers. Finally, we evaluated two CD169-targeting nanovaccine platforms, antibody-based and liposome-based, and we showed that CD169+ monocytes efficiently presented tumor-associated peptides gp100 and WT1 to antigen-specific CD8+ T cells. In conclusion, our data indicate that CD169+ monocytes are activated monocytes with enhanced CD8+ T cell stimulatory capacity and that they emerge as an interesting target in nanovaccine strategies, because of their presence in health and different diseases.


Subject(s)
Antigen Presentation/immunology , CD8-Positive T-Lymphocytes/immunology , Lymphocyte Activation/immunology , Monocytes/immunology , Sialic Acid Binding Ig-like Lectin 1/metabolism , COVID-19/immunology , Carcinoma, Pancreatic Ductal/immunology , Cells, Cultured , Flow Cytometry , Humans , Influenza, Human/immunology , Interferon-alpha/pharmacology , Lipopolysaccharide Receptors/metabolism , Lung Neoplasms/immunology , Pancreatic Neoplasms/immunology , SARS-CoV-2/immunology
3.
Biomark Med ; 15(12): 987-997, 2021 08.
Article in English | MEDLINE | ID: covidwho-1320567

ABSTRACT

Aim: We investigated the effect of pre-analytical sample handling variations on coronavirus disease 2019-relevant circulating cytokine levels IFN-γ, IL-10, IL-12p70, IL-17A, IL-6 and TNF-α. Materials & methods: We collected blood in different collection tubes (ethylenediaminetetraacetic acid, sodium citrate, lithium heparin, serum), and subjected ethylenediaminetetraacetic acid plasma to among others increasing delays in centrifugation or -80°C storage. Six subjects were included in each experimental condition. Cytokine levels were measured in these samples using the Simoa Cytokine 6-plex kit. Results: Different tube types resulted in different blood cytokine levels. IL-17A and IL-6 levels declined with 3 h centrifugation delay. IFN-γ levels declined with 24 h postcentrifugation storage delay. IL-17A levels declined with 2-week storage delay. Conclusion: It is recommended to centrifuge tubes quickly following collection, for accurate cytokine measurement.


Subject(s)
Biological Specimen Banks/standards , COVID-19/blood , Cytokines/blood , Quality Control , SARS-CoV-2/metabolism , Specimen Handling/standards , Adult , Female , Humans , Male , Middle Aged
4.
Respirology ; 26(9): 869-877, 2021 09.
Article in English | MEDLINE | ID: covidwho-1280373

ABSTRACT

BACKGROUND AND OBJECTIVE: Patients with coronavirus disease 2019 (COVID-19) pneumonia present with typical findings on chest computed tomography (CT), but the underlying histopathological patterns are unknown. Through direct regional correlation of imaging findings to histopathological patterns, this study aimed to explain typical COVID-19 CT patterns at tissue level. METHODS: Eight autopsy cases were prospectively selected of patients with PCR-proven COVID-19 pneumonia with varying clinical manifestations and causes of death. All had been subjected to chest CT imaging 24-72 h prior to death. Twenty-seven lung areas with typical COVID-19 patterns and two radiologically unaffected pulmonary areas were correlated to histopathological findings in the same lung regions. RESULTS: Two dominant radiological patterns were observed: ground-glass opacity (GGO) (n = 11) and consolidation (n = 16). In seven of 11 sampled areas of GGO, diffuse alveolar damage (DAD) was observed. In four areas of GGO, the histological pattern was vascular damage and thrombosis, with (n = 2) or without DAD (n = 2). DAD was also observed in five of 16 samples derived from areas of radiological consolidation. Seven areas of consolidation were based on a combination of DAD, vascular damage and thrombosis. In four areas of consolidation, bronchopneumonia was found. Unexpectedly, in samples from radiologically unaffected lung parenchyma, evidence was found of vascular damage and thrombosis. CONCLUSION: In COVID-19, radiological findings of GGO and consolidation are mostly explained by DAD or a combination of DAD and vascular damage plus thrombosis. However, the different typical CT patterns in COVID-19 are not related to specific histopathological patterns. Microvascular damage and thrombosis are even encountered in the radiologically normal lung.


Subject(s)
COVID-19 , Lung , Tomography, X-Ray Computed , Autopsy , COVID-19/diagnostic imaging , Humans , Lung/diagnostic imaging , Retrospective Studies
5.
Lancet Respir Med ; 9(9): 957-968, 2021 09.
Article in English | MEDLINE | ID: covidwho-1275790

ABSTRACT

BACKGROUND: The major complication of COVID-19 is hypoxaemic respiratory failure from capillary leak and alveolar oedema. Experimental and early clinical data suggest that the tyrosine-kinase inhibitor imatinib reverses pulmonary capillary leak. METHODS: This randomised, double-blind, placebo-controlled, clinical trial was done at 13 academic and non-academic teaching hospitals in the Netherlands. Hospitalised patients (aged ≥18 years) with COVID-19, as confirmed by an RT-PCR test for SARS-CoV-2, requiring supplemental oxygen to maintain a peripheral oxygen saturation of greater than 94% were eligible. Patients were excluded if they had severe pre-existing pulmonary disease, had pre-existing heart failure, had undergone active treatment of a haematological or non-haematological malignancy in the previous 12 months, had cytopenia, or were receiving concomitant treatment with medication known to strongly interact with imatinib. Patients were randomly assigned (1:1) to receive either oral imatinib, given as a loading dose of 800 mg on day 0 followed by 400 mg daily on days 1-9, or placebo. Randomisation was done with a computer-based clinical data management platform with variable block sizes (containing two, four, or six patients), stratified by study site. The primary outcome was time to discontinuation of mechanical ventilation and supplemental oxygen for more than 48 consecutive hours, while being alive during a 28-day period. Secondary outcomes included safety, mortality at 28 days, and the need for invasive mechanical ventilation. All efficacy and safety analyses were done in all randomised patients who had received at least one dose of study medication (modified intention-to-treat population). This study is registered with the EU Clinical Trials Register (EudraCT 2020-001236-10). FINDINGS: Between March 31, 2020, and Jan 4, 2021, 805 patients were screened, of whom 400 were eligible and randomly assigned to the imatinib group (n=204) or the placebo group (n=196). A total of 385 (96%) patients (median age 64 years [IQR 56-73]) received at least one dose of study medication and were included in the modified intention-to-treat population. Time to discontinuation of ventilation and supplemental oxygen for more than 48 h was not significantly different between the two groups (unadjusted hazard ratio [HR] 0·95 [95% CI 0·76-1·20]). At day 28, 15 (8%) of 197 patients had died in the imatinib group compared with 27 (14%) of 188 patients in the placebo group (unadjusted HR 0·51 [0·27-0·95]). After adjusting for baseline imbalances between the two groups (sex, obesity, diabetes, and cardiovascular disease) the HR for mortality was 0·52 (95% CI 0·26-1·05). The HR for mechanical ventilation in the imatinib group compared with the placebo group was 1·07 (0·63-1·80; p=0·81). The median duration of invasive mechanical ventilation was 7 days (IQR 3-13) in the imatinib group compared with 12 days (6-20) in the placebo group (p=0·0080). 91 (46%) of 197 patients in the imatinib group and 82 (44%) of 188 patients in the placebo group had at least one grade 3 or higher adverse event. The safety evaluation revealed no imatinib-associated adverse events. INTERPRETATION: The study failed to meet its primary outcome, as imatinib did not reduce the time to discontinuation of ventilation and supplemental oxygen for more than 48 consecutive hours in patients with COVID-19 requiring supplemental oxygen. The observed effects on survival (although attenuated after adjustment for baseline imbalances) and duration of mechanical ventilation suggest that imatinib might confer clinical benefit in hospitalised patients with COVID-19, but further studies are required to validate these findings. FUNDING: Amsterdam Medical Center Foundation, Nederlandse Organisatie voor Wetenschappelijk Onderzoek/ZonMW, and the European Union Innovative Medicines Initiative 2.


Subject(s)
COVID-19/therapy , Imatinib Mesylate/administration & dosage , Protein Kinase Inhibitors/administration & dosage , Respiration, Artificial/statistics & numerical data , Respiratory Insufficiency/therapy , Aged , COVID-19/complications , COVID-19/diagnosis , COVID-19/virology , Capillary Permeability/drug effects , Combined Modality Therapy/adverse effects , Combined Modality Therapy/methods , Double-Blind Method , Female , Humans , Imatinib Mesylate/adverse effects , Male , Middle Aged , Netherlands , Oxygen/administration & dosage , Placebos/administration & dosage , Placebos/adverse effects , Protein Kinase Inhibitors/adverse effects , Respiratory Insufficiency/diagnosis , Respiratory Insufficiency/virology , SARS-CoV-2/isolation & purification , Severity of Illness Index , Time Factors , Treatment Outcome
6.
Front Immunol ; 12: 664209, 2021.
Article in English | MEDLINE | ID: covidwho-1247863

ABSTRACT

Rationale: Systemic activation of procoagulant and inflammatory mechanisms has been implicated in the pathogenesis of COVID-19. Knowledge of activation of these host response pathways in the lung compartment of COVID-19 patients is limited. Objectives: To evaluate local and systemic activation of coagulation and interconnected inflammatory responses in critically ill COVID-19 patients with persistent acute respiratory distress syndrome. Methods: Paired bronchoalveolar lavage fluid and plasma samples were obtained from 17 patients with COVID-19 related persistent acute respiratory distress syndrome (mechanical ventilation > 7 days) 1 and 2 weeks after start mechanical ventilation and compared with 8 healthy controls. Thirty-four host response biomarkers stratified into five functional domains (coagulation, complement system, cytokines, chemokines and growth factors) were measured. Measurements and Main Results: In all patients, all functional domains were activated, especially in the bronchoalveolar compartment, with significantly increased levels of D-dimers, thrombin-antithrombin complexes, soluble tissue factor, C1-inhibitor antigen and activity levels, tissue type plasminogen activator, plasminogen activator inhibitor type I, soluble CD40 ligand and soluble P-selectin (coagulation), next to activation of C3bc and C4bc (complement) and multiple interrelated cytokines, chemokines and growth factors. In 10 patients in whom follow-up samples were obtained between 3 and 4 weeks after start mechanical ventilation many bronchoalveolar and plasma host response biomarkers had declined. Conclusions: Critically ill, ventilated patients with COVID-19 show strong responses relating to coagulation, the complement system, cytokines, chemokines and growth factors in the bronchoalveolar compartment. These results suggest a local pulmonary rather than a systemic procoagulant and inflammatory "storm" in severe COVID-19.


Subject(s)
COVID-19/immunology , Critical Illness , Lung/metabolism , Respiratory Distress Syndrome/immunology , SARS-CoV-2/physiology , Thromboplastin/metabolism , Aged , Blood Coagulation , Cohort Studies , Female , Fibrin Fibrinogen Degradation Products/metabolism , Follow-Up Studies , Humans , Immunity, Innate , Lung/pathology , Male , Middle Aged , Respiration, Artificial
7.
Thorax ; 76(10): 1010-1019, 2021 10.
Article in English | MEDLINE | ID: covidwho-1180971

ABSTRACT

BACKGROUND: Knowledge of the pathophysiology of COVID-19 is almost exclusively derived from studies that examined the immune response in blood. We here aimed to analyse the pulmonary immune response during severe COVID-19 and to compare this with blood responses. METHODS: This was an observational study in patients with COVID-19 admitted to the intensive care unit (ICU). Mononuclear cells were purified from bronchoalveolar lavage fluid (BALF) and blood, and analysed by spectral flow cytometry; inflammatory mediators were measured in BALF and plasma. FINDINGS: Paired blood and BALF samples were obtained from 17 patients, four of whom died in the ICU. Macrophages and T cells were the most abundant cells in BALF, with a high percentage of T cells expressing the ƴδ T cell receptor. In the lungs, both CD4 and CD8 T cells were predominantly effector memory cells (87·3% and 83·8%, respectively), and these cells expressed higher levels of the exhaustion marker programmad death-1 than in peripheral blood. Prolonged ICU stay (>14 days) was associated with a reduced proportion of activated T cells in peripheral blood and even more so in BALF. T cell activation in blood, but not in BALF, was higher in fatal COVID-19 cases. Increased levels of inflammatory mediators were more pronounced in BALF than in plasma. INTERPRETATION: The bronchoalveolar immune response in COVID-19 has a unique local profile that strongly differs from the immune profile in peripheral blood. Fully elucidating COVID-19 pathophysiology will require investigation of the pulmonary immune response.


Subject(s)
COVID-19/immunology , Immunity, Cellular/physiology , Inflammation Mediators/metabolism , Aged , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/cytology , COVID-19/blood , COVID-19/pathology , Critical Care , Critical Illness , Female , Flow Cytometry , Humans , Macrophages/physiology , Male , Middle Aged , T-Lymphocytes/physiology
8.
Eur J Immunol ; 51(6): 1535-1538, 2021 06.
Article in English | MEDLINE | ID: covidwho-1151896

ABSTRACT

Despite high levels of CXCR3 ligands in mechanically ventilated COVID-19 patients, BALF CD8 T cells were not enriched in CXCR3+ cells but rather CCR6+ , likely due to high CCL20 levels in BALF, and had very high PD-1 expression. In mechanically ventilated, but not ward, patients Th-1 immunity is impaired. ​.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Chemokine CCL20/immunology , Lung/immunology , Receptors, CCR6/immunology , Respiration, Artificial , SARS-CoV-2/immunology , Aged , Aged, 80 and over , CD8-Positive T-Lymphocytes/pathology , COVID-19/pathology , COVID-19/therapy , Female , Humans , Lung/pathology , Lymphocyte Count , Male , Middle Aged
9.
Eur J Intern Med ; 83: 1-5, 2021 01.
Article in English | MEDLINE | ID: covidwho-1065035

ABSTRACT

IMPORTANCE: Among COVID-19 cases, especially the (frail) elderly show a high number of severe infections, hospital admissions, complications, and death. The highest mortality is found between 80 and 89 years old. Why do these patients have a higher risk of severe COVID-19? In this narrative review we address potential mechanisms regarding viral transmission, physical reserve and the immune system, increasing the severity of this infection in elderly patients. OBSERVATIONS: First, the spread of COVID-19 may be enhanced in elderly patients. Viral shedding may be increased, and early identification may be complicated due to atypical disease presentation and limited testing capacity. Applying hygiene and quarantine measures, especially in patients with cognitive disorders including dementia, can be challenging. Additionally, elderly patients have a decreased cardiorespiratory reserve and are more likely to have co-morbidity including atherosclerosis, rendering them more susceptible to complications. The aging innate and adaptive immune system is weakened, while there is a pro-inflammatory tendency. The effects of SARS-CoV-2 on the immune system on cytokine production and T-cells, further seem to aggravate this pro-inflammatory tendency, especially in patients with cardiovascular comorbidity, increasing disease severity. CONCLUSIONS AND RELEVANCE: The combination of all factors mentioned above contribute to the disease severity of COVID-19 in the older patient. While larger studies of COVID-19 in elderly patients are needed, understanding the factors increasing disease severity may improve care and preventative measures to protect the elderly patient at risk for (severe) COVID-19 in the future.


Subject(s)
COVID-19/etiology , SARS-CoV-2/pathogenicity , Age Factors , Aged , Aged, 80 and over , COVID-19/mortality , Humans , Risk Factors
10.
Eur J Immunol ; 50(12): 1998-2012, 2020 Dec.
Article in English | MEDLINE | ID: covidwho-871354

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the current coronavirus disease 2019 (COVID-19) pandemic. Understanding the immune response that provides specific immunity but may also lead to immunopathology is crucial for the design of potential preventive and therapeutic strategies. Here, we characterized and quantified SARS-CoV-2-specific immune responses in patients with different clinical courses. Compared to individuals with a mild clinical presentation, CD4+ T-cell responses were qualitatively impaired in critically ill patients. Strikingly, however, in these patients the specific IgG antibody response was remarkably strong. Furthermore, in these critically ill patients, a massive influx of circulating T cells into the lungs was observed, overwhelming the local T-cell compartment, and indicative of vascular leakage. The observed disparate T- and B-cell responses could be indicative of a deregulated immune response in critically ill COVID-19 patients.


Subject(s)
Antibodies, Viral/immunology , B-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/immunology , COVID-19/immunology , Immunoglobulin G/immunology , SARS-CoV-2/immunology , Adult , Aged , B-Lymphocytes/pathology , CD4-Positive T-Lymphocytes/pathology , COVID-19/pathology , Female , Humans , Male , Middle Aged , Severity of Illness Index
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