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1.
Lancet Infect Dis ; 20(11): e276-e288, 2020 11.
Article in English | MEDLINE | ID: covidwho-2062013

ABSTRACT

As severe acute respiratory syndrome coronavirus 2 continues to spread worldwide, there have been increasing reports from Europe, North America, Asia, and Latin America describing children and adolescents with COVID-19-associated multisystem inflammatory conditions. However, the association between multisystem inflammatory syndrome in children and COVID-19 is still unknown. We review the epidemiology, causes, clinical features, and current treatment protocols for multisystem inflammatory syndrome in children and adolescents associated with COVID-19. We also discuss the possible underlying pathophysiological mechanisms for COVID-19-induced inflammatory processes, which can lead to organ damage in paediatric patients who are severely ill. These insights provide evidence for the need to develop a clear case definition and treatment protocol for this new condition and also shed light on future therapeutic interventions and the potential for vaccine development. TRANSLATIONS: For the French, Chinese, Arabic, Spanish and Russian translations of the abstract see Supplementary Materials section.


Subject(s)
Betacoronavirus , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Systemic Inflammatory Response Syndrome/epidemiology , Systemic Inflammatory Response Syndrome/immunology , Adolescent , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Antiviral Agents/therapeutic use , COVID-19 , Child , Child, Preschool , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Female , Humans , Immunoglobulins, Intravenous/therapeutic use , Infant , Infant, Newborn , Male , Mucocutaneous Lymph Node Syndrome/drug therapy , Mucocutaneous Lymph Node Syndrome/immunology , Pandemics , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Risk Factors , SARS-CoV-2 , Systemic Inflammatory Response Syndrome/drug therapy , Systemic Inflammatory Response Syndrome/virology , Young Adult
2.
J Exp Med ; 219(2)2022 02 07.
Article in English | MEDLINE | ID: covidwho-1984990

ABSTRACT

In rare instances, pediatric SARS-CoV-2 infection results in a novel immunodysregulation syndrome termed multisystem inflammatory syndrome in children (MIS-C). We compared MIS-C immunopathology with severe COVID-19 in adults. MIS-C does not result in pneumocyte damage but is associated with vascular endotheliitis and gastrointestinal epithelial injury. In MIS-C, the cytokine release syndrome is characterized by IFNγ and not type I interferon. Persistence of patrolling monocytes differentiates MIS-C from severe COVID-19, which is dominated by HLA-DRlo classical monocytes. IFNγ levels correlate with granzyme B production in CD16+ NK cells and TIM3 expression on CD38+/HLA-DR+ T cells. Single-cell TCR profiling reveals a skewed TCRß repertoire enriched for TRBV11-2 and a superantigenic signature in TIM3+/CD38+/HLA-DR+ T cells. Using NicheNet, we confirm IFNγ as a central cytokine in the communication between TIM3+/CD38+/HLA-DR+ T cells, CD16+ NK cells, and patrolling monocytes. Normalization of IFNγ, loss of TIM3, quiescence of CD16+ NK cells, and contraction of patrolling monocytes upon clinical resolution highlight their potential role in MIS-C immunopathogenesis.


Subject(s)
COVID-19/complications , Hepatitis A Virus Cellular Receptor 2/metabolism , Interferon-gamma/metabolism , Killer Cells, Natural/immunology , Monocytes/metabolism , Receptors, IgG/metabolism , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , Adolescent , Alveolar Epithelial Cells/pathology , B-Lymphocytes/immunology , Blood Vessels/pathology , COVID-19/immunology , COVID-19/pathology , Cell Proliferation , Child , Cohort Studies , Complement Activation , Cytokines/metabolism , Enterocytes/pathology , Female , Humans , Immunity, Humoral , Inflammation/pathology , Interferon Type I/metabolism , Interleukin-15/metabolism , Lymphocyte Activation/immunology , Male , Receptors, Antigen, T-Cell/metabolism , SARS-CoV-2/immunology , Superantigens/metabolism , Systemic Inflammatory Response Syndrome/pathology
3.
Front Immunol ; 12: 793197, 2021.
Article in English | MEDLINE | ID: covidwho-1674334

ABSTRACT

Background: Despite similar rates of infection, adults and children have markedly different morbidity and mortality related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Compared to adults, children have infrequent severe manifestations of acute infection but are uniquely at risk for the rare and often severe Multisystem Inflammatory Syndrome in Children (MIS-C) following infection. We hypothesized that these differences in presentation are related to differences in the magnitude and/or antigen specificity of SARS-CoV-2-specific T cell (CST) responses between adults and children. We therefore set out to measure the CST response in convalescent adults versus children with and without MIS-C following SARS-CoV-2 infection. Methods: CSTs were expanded from blood collected from convalescent children and adults post SARS-CoV-2 infection and evaluated by intracellular flow cytometry, surface markers, and cytokine production following stimulation with SARS-CoV-2-specific peptides. Presence of serum/plasma antibody to spike and nucleocapsid was measured using the luciferase immunoprecipitation systems (LIPS) assay. Findings: Twenty-six of 27 MIS-C patients, 7 of 8 non-MIS-C convalescent children, and 13 of 14 adults were seropositive for spike and nucleocapsid antibody. CST responses in MIS-C patients were significantly higher than children with uncomplicated SARS-CoV-2 infection, but weaker than CST responses in convalescent adults. Interpretation: Age-related differences in the magnitude of CST responses suggest differing post-infectious immunity to SARS-CoV-2 in children compared to adults post uncomplicated infection. Children with MIS-C have CST responses that are stronger than children with uncomplicated SARS-CoV-2 infection and weaker than convalescent adults, despite near uniform seropositivity.


Subject(s)
COVID-19/complications , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , Adolescent , Adult , Antibodies, Viral/immunology , COVID-19/immunology , Child , Child, Preschool , Convalescence , Coronavirus Nucleocapsid Proteins/immunology , Female , Humans , Infant , Male , Middle Aged , Phosphoproteins/immunology , Spike Glycoprotein, Coronavirus/immunology
4.
Nat Immunol ; 23(2): 177-185, 2022 02.
Article in English | MEDLINE | ID: covidwho-1671601

ABSTRACT

Children and adolescents exhibit a broad range of clinical outcomes from SARS-CoV-2 infection, with the majority having minimal to mild symptoms. Additionally, some succumb to a severe hyperinflammatory post-infectious complication called multisystem inflammatory syndrome in children (MIS-C), predominantly affecting previously healthy individuals. Studies characterizing the immunological differences associated with these clinical outcomes have identified pathways important for host immunity to SARS-CoV-2 and innate modulators of disease severity. In this Review, we delineate the immunological mechanisms underlying the spectrum of pediatric immune response to SARS-CoV-2 infection in comparison with that of adults.


Subject(s)
COVID-19/complications , COVID-19/immunology , Immunity, Innate , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Adolescent , Adolescent Development , Age Factors , Asymptomatic Diseases , COVID-19/diagnosis , COVID-19/virology , Child , Child Development , Comorbidity , Host-Pathogen Interactions , Humans , Risk Factors , SARS-CoV-2/pathogenicity , Severity of Illness Index , Systemic Inflammatory Response Syndrome/diagnosis , Systemic Inflammatory Response Syndrome/virology
5.
APMIS ; 130(2): 101-110, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1650387

ABSTRACT

In the milieu of coronavirus disease 2019 (COVID-19), there are increasing reports of paediatric hyperinflammatory conditions (PHICs), including multisystem inflammatory syndrome in children (MIS-C), paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and Kawasaki disease (KD). Few analyses of PHIC prevalence in paediatric and adolescent hospitalized COVID-19 patients exist. The purpose of this study was to perform a meta-analysis to determine a pooled prevalence estimate of PHICs in paediatric and adolescent hospitalized patients admitted for treatment due to COVID-19. Individual studies were retrieved from PubMed/Medline, EMBASE and Cochrane databases. Relevant prevalence, baseline, treatment and outcome data were extracted using a standardized datasheet. The systematic review and meta-analysis were conducted as per the PRISMA and MOOSE guidelines. Overall, 14 studies with 2202 patients admitted for treatment due to COVID-19, among whom 780 were diagnosed with PHICs, were included. The crude estimate of prevalence was 35.42%, and the pooled estimate of prevalence was 29% (random pooled ES = 0.29; 95% CIs = 0.18-0.42; p < 0.0001; z = 7.45). A sizeable proportion of paediatric and adolescent hospitalized patients admitted for treatment due to COVID-19 are diagnosed with a PHIC warranting a high index of clinical suspicion for PHICs. Further studies are required to validate these findings.


Subject(s)
COVID-19/complications , Mucocutaneous Lymph Node Syndrome/epidemiology , Systemic Inflammatory Response Syndrome/epidemiology , Adolescent , COVID-19/epidemiology , COVID-19/immunology , COVID-19/therapy , COVID-19/virology , Child , Child, Preschool , Female , Hospitalization , Humans , Infant , Male , Mucocutaneous Lymph Node Syndrome/immunology , Mucocutaneous Lymph Node Syndrome/therapy , Mucocutaneous Lymph Node Syndrome/virology , Prevalence , SARS-CoV-2/physiology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/therapy , Systemic Inflammatory Response Syndrome/virology
6.
JCI Insight ; 7(4)2022 02 22.
Article in English | MEDLINE | ID: covidwho-1637818

ABSTRACT

Why multisystem inflammatory syndrome in children (MIS-C) develops after SARS-CoV-2 infection in a subset of children is unknown. We hypothesized that aberrant virus-specific T cell responses contribute to MIS-C pathogenesis. We quantified SARS-CoV-2-reactive T cells, serologic responses against major viral proteins, and cytokine responses from plasma and peripheral blood mononuclear cells in children with convalescent COVID-19, in children with acute MIS-C, and in healthy controls. Children with MIS-C had significantly lower virus-specific CD4+ and CD8+ T cell responses to major SARS-CoV-2 antigens compared with children convalescing from COVID-19. Furthermore, T cell responses in participants with MIS-C were similar to or lower than those in healthy controls. Serologic responses against spike receptor binding domain (RBD), full-length spike, and nucleocapsid were similar among convalescent COVID-19 and MIS-C, suggesting functional B cell responses. Cytokine profiling demonstrated predominant Th1 polarization of CD4+ T cells from children with convalescent COVID-19 and MIS-C, although cytokine production was reduced in MIS-C. Our findings support a role for constrained induction of anti-SARS-CoV-2-specific T cells in the pathogenesis of MIS-C.


Subject(s)
COVID-19/complications , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , Adolescent , COVID-19/immunology , Child , Child, Preschool , Female , Humans , Male
7.
Am J Dermatopathol ; 44(3): 183-189, 2022 Mar 01.
Article in English | MEDLINE | ID: covidwho-1608833

ABSTRACT

INTRODUCTION: A new entity, which occurs a few weeks after SARS-CoV-2 infection and resembling incomplete Kawasaki disease or toxic shock syndrome, has been defined and named multisystem inflammatory syndrome (MIS-C) associated with COVID-19 in children. The aim of our study was to describe histopathological characteristics of skin lesions of MIS-C patients to reveal whether there is a relationship between histopathological features and clinical manifestations. MATERIALS AND METHODS: Seventeen who had skin involvement of 57 patients who were diagnosed with MIS-C between December 2020 and February 2021 were included in this prospective study. Demographic information, laboratory findings, and patients' managements were recorded. Skin biopsies were taken simultaneously of each patient. Formalin-fixed, paraffin-embedded skin samples were examined microscopically. RESULTS: The rate of skin rash was 30% in patients with MIS-C and was predominantly the maculopapular type. The anatomical distribution of the rash was evaluated as localized in 10 and generalized in 7 patients. In patients with myocarditis, C-reactive protein and fibrinogen were found to be significantly higher, and lymphocyte and albumin values were found to be low. Herpes-like inclusions were found in the microscopic examination of 2 patients with a history of zona zoster in themselves or in their mother. There was a significant difference between keratinocyte necrosis and some clinical parameters. DISCUSSION: Localized skin lesions appear to be associated with a more severe inflammatory.


Subject(s)
COVID-19/complications , Exanthema/etiology , Skin/pathology , Systemic Inflammatory Response Syndrome/complications , Adolescent , Biopsy , COVID-19/immunology , COVID-19/virology , Child , Child, Preschool , Exanthema/immunology , Exanthema/pathology , Female , Humans , Male , Prospective Studies , Skin/immunology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/virology
8.
N Engl J Med ; 385(1): 11-22, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1585668

ABSTRACT

BACKGROUND: Evidence is urgently needed to support treatment decisions for children with multisystem inflammatory syndrome (MIS-C) associated with severe acute respiratory syndrome coronavirus 2. METHODS: We performed an international observational cohort study of clinical and outcome data regarding suspected MIS-C that had been uploaded by physicians onto a Web-based database. We used inverse-probability weighting and generalized linear models to evaluate intravenous immune globulin (IVIG) as a reference, as compared with IVIG plus glucocorticoids and glucocorticoids alone. There were two primary outcomes: the first was a composite of inotropic support or mechanical ventilation by day 2 or later or death; the second was a reduction in disease severity on an ordinal scale by day 2. Secondary outcomes included treatment escalation and the time until a reduction in organ failure and inflammation. RESULTS: Data were available regarding the course of treatment for 614 children from 32 countries from June 2020 through February 2021; 490 met the World Health Organization criteria for MIS-C. Of the 614 children with suspected MIS-C, 246 received primary treatment with IVIG alone, 208 with IVIG plus glucocorticoids, and 99 with glucocorticoids alone; 22 children received other treatment combinations, including biologic agents, and 39 received no immunomodulatory therapy. Receipt of inotropic or ventilatory support or death occurred in 56 patients who received IVIG plus glucocorticoids (adjusted odds ratio for the comparison with IVIG alone, 0.77; 95% confidence interval [CI], 0.33 to 1.82) and in 17 patients who received glucocorticoids alone (adjusted odds ratio, 0.54; 95% CI, 0.22 to 1.33). The adjusted odds ratios for a reduction in disease severity were similar in the two groups, as compared with IVIG alone (0.90 for IVIG plus glucocorticoids and 0.93 for glucocorticoids alone). The time until a reduction in disease severity was similar in the three groups. CONCLUSIONS: We found no evidence that recovery from MIS-C differed after primary treatment with IVIG alone, IVIG plus glucocorticoids, or glucocorticoids alone, although significant differences may emerge as more data accrue. (Funded by the European Union's Horizon 2020 Program and others; BATS ISRCTN number, ISRCTN69546370.).


Subject(s)
COVID-19/drug therapy , Glucocorticoids/therapeutic use , Immunoglobulins, Intravenous/therapeutic use , Systemic Inflammatory Response Syndrome/drug therapy , Adolescent , Antibodies, Viral , COVID-19/immunology , COVID-19/mortality , COVID-19/therapy , Child , Child, Preschool , Cohort Studies , Confidence Intervals , Drug Therapy, Combination , Female , Hospitalization , Humans , Immunomodulation , Male , Propensity Score , Regression Analysis , Respiration, Artificial , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/mortality , Systemic Inflammatory Response Syndrome/therapy , Treatment Outcome
9.
Front Immunol ; 12: 779026, 2021.
Article in English | MEDLINE | ID: covidwho-1581330

ABSTRACT

A 26-year-old otherwise healthy man died of fulminant myocarditis. Nasopharyngeal specimens collected premortem tested negative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Histopathological evaluation of the heart showed myocardial necrosis surrounded by cytotoxic T-cells and tissue-repair macrophages. Myocardial T-cell receptor (TCR) sequencing revealed hyper-dominant clones with highly similar sequences to TCRs that are specific for SARS-CoV-2 epitopes. SARS-CoV-2 RNA was detected in the gut, supporting a diagnosis of multisystem inflammatory syndrome in adults (MIS-A). Molecular targets of MIS-associated inflammation are not known. Our data indicate that SARS-CoV-2 antigens selected high-frequency T-cell clones that mediated fatal myocarditis.


Subject(s)
COVID-19/complications , Myocarditis/pathology , Myocarditis/virology , Systemic Inflammatory Response Syndrome/pathology , T-Lymphocytes/immunology , Adult , COVID-19/immunology , COVID-19/pathology , Humans , Male , Myocarditis/immunology , RNA, Viral/analysis , SARS-CoV-2 , Systemic Inflammatory Response Syndrome/immunology
10.
Viruses ; 13(11)2021 11 03.
Article in English | MEDLINE | ID: covidwho-1542790

ABSTRACT

The detailed characterization of human γδ T lymphocyte differentiation at the single-cell transcriptomic (scRNAseq) level in tumors and patients with coronavirus disease 2019 (COVID-19) requires both a reference differentiation trajectory of γδ T cells and a robust mapping method for additional γδ T lymphocytes. Here, we incepted such a method to characterize thousands of γδ T lymphocytes from (n = 95) patients with cancer or adult and pediatric COVID-19 disease. We found that cancer patients with human papillomavirus-positive head and neck squamous cell carcinoma and Epstein-Barr virus-positive Hodgkin's lymphoma have γδ tumor-infiltrating T lymphocytes that are more prone to recirculate from the tumor and avoid exhaustion. In COVID-19, both TCRVγ9 and TCRVγnon9 subsets of γδ T lymphocytes relocalize from peripheral blood mononuclear cells (PBMC) to the infected lung tissue, where their advanced differentiation, tissue residency, and exhaustion reflect T cell activation. Although severe COVID-19 disease increases both recruitment and exhaustion of γδ T lymphocytes in infected lung lesions but not blood, the anti-IL6R therapy with Tocilizumab promotes γδ T lymphocyte differentiation in patients with COVID-19. PBMC from pediatric patients with acute COVID-19 disease display similar γδ T cell lymphopenia to that seen in adult patients. However, blood γδ T cells from children with the COVID-19-related multisystem inflammatory syndrome are not lymphodepleted, but they are differentiated as in healthy PBMC. These findings suggest that some virus-induced memory γδ T lymphocytes durably persist in the blood of adults and could subsequently infiltrate and recirculate in tumors.


Subject(s)
COVID-19/immunology , Lymphocytes, Tumor-Infiltrating/immunology , Neoplasms/immunology , RNA-Seq , Receptors, Antigen, T-Cell, gamma-delta/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Adult , Bronchoalveolar Lavage Fluid/immunology , COVID-19/complications , Cell Differentiation , Child , Head and Neck Neoplasms/immunology , Head and Neck Neoplasms/virology , Herpesvirus 4, Human/isolation & purification , Hodgkin Disease/immunology , Hodgkin Disease/virology , Humans , Lung/immunology , Lymphocyte Activation , Lymphocyte Count , Lymphocytes, Tumor-Infiltrating/metabolism , Lymphocytes, Tumor-Infiltrating/physiology , Neoplasms/virology , Papillomaviridae/isolation & purification , Severity of Illness Index , Single-Cell Analysis , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocyte Subsets/physiology
11.
J Allergy Clin Immunol ; 149(3): 912-922, 2022 03.
Article in English | MEDLINE | ID: covidwho-1536619

ABSTRACT

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is an acute, febrile, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-associated syndrome, often with cardiohemodynamic dysfunction. Insight into mechanism of disease is still incomplete. OBJECTIVE: Our objective was to analyze immunologic features of MIS-C patients compared to febrile controls (FC). METHODS: MIS-C patients were defined by narrow criteria, including having evidence of cardiohemodynamic involvement and no macrophage activation syndrome. Samples were collected from 8 completely treatment-naive patients with MIS-C (SARS-CoV-2 serology positive), 3 patients with unclassified MIS-C-like disease (serology negative), 14 FC, and 5 MIS-C recovery (RCV). Three healthy controls (HCs) were used for comparisons of normal range. Using spectral flow cytometry, we assessed 36 parameters in antigen-presenting cells (APCs) and 29 in T cells. We used biaxial analysis and uniform manifold approximation and projection (UMAP). RESULTS: Significant elevations in cytokines including CXCL9, M-CSF, and IL-27 were found in MIS-C compared to FC. Classic monocytes and type 2 dendritic cells (DCs) were downregulated (decreased CD86, HLA-DR) versus HCs; however, type 1 DCs (CD11c+CD141+CLEC9A+) were highly activated in MIS-C patients versus FC, expressing higher levels of CD86, CD275, and atypical conventional DC markers such as CD64, CD115, and CX3CR1. CD169 and CD38 were upregulated in multiple monocyte subtypes. CD56dim/CD57-/KLRGhi/CD161+/CD38- natural killer (NK) cells were a unique subset in MIS-C versus FC without macrophage activation syndrome. CONCLUSION: Orchestrated by complex cytokine signaling, type 1 DC activation and NK dysregulation are key features in the pathophysiology of MIS-C. NK cell findings may suggest a relationship with macrophage activation syndrome, while type 1 DC upregulation implies a role for antigen cross-presentation.


Subject(s)
COVID-19/complications , Dendritic Cells/immunology , Dendritic Cells/virology , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/virology , ADP-ribosyl Cyclase 1/blood , Adolescent , Antigens, Viral/immunology , COVID-19/immunology , COVID-19/virology , Case-Control Studies , Child , Child, Preschool , Cross-Priming , Cytokines/blood , Dendritic Cells/classification , Female , HLA-DR Antigens/blood , Humans , Immunophenotyping , Interferon-gamma/blood , Interleukins/blood , Killer Cells, Natural/immunology , Male , Membrane Glycoproteins/blood , Models, Immunological , Monocytes/immunology , Sialic Acid Binding Ig-like Lectin 1/blood , T-Lymphocytes/immunology , T-Lymphocytes/virology , Up-Regulation
12.
Pediatr Nephrol ; 36(9): 2627-2638, 2021 09.
Article in English | MEDLINE | ID: covidwho-1520348

ABSTRACT

BACKGROUND AND OBJECTIVES: COVID-19 is responsible for the 2019 novel coronavirus disease pandemic. Despite the vast research about the adult population, there has been little data collected on acute kidney injury (AKI) epidemiology, associated risk factors, treatments, and mortality in pediatric COVID-19 patients admitted to the ICU. AKI is a severe complication of COVID-19 among children and adolescents. METHODS: A comprehensive literature search was conducted in PubMed/MEDLINE and Cochrane Center Trials to find all published literature related to AKI in COVID-19 patients, including incidence and outcomes. RESULTS: Twenty-four studies reporting the outcomes of interest were included. Across all studies, the overall sample size of COVID positive children was 1,247 and the median age of this population was 9.1 years old. Among COVID positive pediatric patients, there was an AKI incidence of 30.51%, with only 0.56% of these patients receiving KRT. The mortality was 2.55% among all COVID positive pediatric patients. The incidence of multisystem inflammatory syndrome in children (MIS-C) among COVID positive patients was 74.29%. CONCLUSION: AKI has shown to be a negative prognostic factor in adult patients with COVID-19 and now also in the pediatric cohort with high incidence and mortality rates. Additionally, our findings show a strong comparison in epidemiology between adult and pediatric COVID-19 patients; however, they need to be confirmed with additional data and studies.


Subject(s)
Acute Kidney Injury/epidemiology , COVID-19/complications , Intensive Care Units/statistics & numerical data , Renal Replacement Therapy/statistics & numerical data , Systemic Inflammatory Response Syndrome/complications , Acute Kidney Injury/immunology , Acute Kidney Injury/therapy , Acute Kidney Injury/virology , Adult , Age Factors , COVID-19/diagnosis , COVID-19/immunology , COVID-19/mortality , Child , Hospital Mortality , Humans , Incidence , Pandemics/statistics & numerical data , Risk Factors , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity , Systemic Inflammatory Response Syndrome/diagnosis , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/mortality
13.
Front Immunol ; 12: 723654, 2021.
Article in English | MEDLINE | ID: covidwho-1504010

ABSTRACT

With the appearance of the SARS-CoV-2 virus in December 2019, all countries in the world have implemented different strategies to prevent its spread and to intensively search for effective treatments. Initially, severe cases of the disease were considered in adult patients; however, cases of older school-age children and adolescents who presented fever, hypotension, severe abdominal pain and cardiac dysfunction, positive for SARS-CoV-2 infection, have been reported, with increased pro-inflammatory cytokines and tissue damage, condition denominated multisystemic inflammatory syndrome (MIS-C); The emerging data from patients with MIS-C have suggested unique characteristics in the immunological response and also clinical similarities with other inflammatory syndromes, which can support as a reference in the search for molecular mechanisms involved in MIS-C. We here in propose that oxidative stress (OE) may play a very important role in the pathophysiology of MIS-C, such as occurs in Kawasaki disease (KD), severe COVID-19 in adults and other processes with characteristics of vascular damage similar to MIS- C, for which we review the available information that can be correlated with possible redox mechanisms.


Subject(s)
COVID-19/complications , Oxidative Stress , SARS-CoV-2/pathogenicity , Systemic Inflammatory Response Syndrome/physiopathology , Adolescent , COVID-19/diagnosis , COVID-19/immunology , COVID-19/physiopathology , Child , Cytokines/immunology , Humans , Inflammation , Systemic Inflammatory Response Syndrome/diagnosis , Systemic Inflammatory Response Syndrome/immunology
14.
Front Immunol ; 12: 738073, 2021.
Article in English | MEDLINE | ID: covidwho-1497076

ABSTRACT

The mechanisms underlying the immune remodeling and severity response in coronavirus disease 2019 (COVID-19) are yet to be fully elucidated. Our comprehensive integrative analyses of single-cell RNA sequencing (scRNAseq) data from four published studies, in patients with mild/moderate and severe infections, indicate a robust expansion and mobilization of the innate immune response and highlight mechanisms by which low-density neutrophils and megakaryocytes play a crucial role in the cross talk between lymphoid and myeloid lineages. We also document a marked reduction of several lymphoid cell types, particularly natural killer cells, mucosal-associated invariant T (MAIT) cells, and gamma-delta T (γδT) cells, and a robust expansion and extensive heterogeneity within plasmablasts, especially in severe COVID-19 patients. We confirm the changes in cellular abundances for certain immune cell types within a new patient cohort. While the cellular heterogeneity in COVID-19 extends across cells in both lineages, we consistently observe certain subsets respond more potently to interferon type I (IFN-I) and display increased cellular abundances across the spectrum of severity, as compared with healthy subjects. However, we identify these expanded subsets to have a more muted response to IFN-I within severe disease compared to non-severe disease. Our analyses further highlight an increased aggregation potential of the myeloid subsets, particularly monocytes, in COVID-19. Finally, we provide detailed mechanistic insights into the interaction between lymphoid and myeloid lineages, which contributes to the multisystemic phenotype of COVID-19, distinguishing severe from non-severe responses.


Subject(s)
COVID-19/immunology , Killer Cells, Natural/immunology , Mucosal-Associated Invariant T Cells/immunology , Neutrophils/immunology , SARS-CoV-2/physiology , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , COVID-19/diagnosis , Cell Differentiation , Cell Proliferation , Humans , Immunity, Innate , Interferon Type I/metabolism , Lymphopoiesis , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Sequence Analysis, RNA , Single-Cell Analysis , Systemic Inflammatory Response Syndrome/diagnosis , T-Lymphocytes/metabolism , Thrombopoiesis
15.
J Clin Invest ; 131(20)2021 10 15.
Article in English | MEDLINE | ID: covidwho-1470549

ABSTRACT

Multisystem inflammatory syndrome in children (MIS-C) manifests as a severe and uncontrolled inflammatory response with multiorgan involvement, occurring weeks after SARS-CoV-2 infection. Here, we utilized proteomics, RNA sequencing, autoantibody arrays, and B cell receptor (BCR) repertoire analysis to characterize MIS-C immunopathogenesis and identify factors contributing to severe manifestations and intensive care unit admission. Inflammation markers, humoral immune responses, neutrophil activation, and complement and coagulation pathways were highly enriched in MIS-C patient serum, with a more hyperinflammatory profile in severe than in mild MIS-C cases. We identified a strong autoimmune signature in MIS-C, with autoantibodies targeted to both ubiquitously expressed and tissue-specific antigens, suggesting autoantigen release and excessive antigenic drive may result from systemic tissue damage. We further identified a cluster of patients with enhanced neutrophil responses as well as high anti-Spike IgG and autoantibody titers. BCR sequencing of these patients identified a strong imprint of antigenic drive with substantial BCR sequence connectivity and usage of autoimmunity-associated immunoglobulin heavy chain variable region (IGHV) genes. This cluster was linked to a TRBV11-2 expanded T cell receptor (TCR) repertoire, consistent with previous studies indicating a superantigen-driven pathogenic process. Overall, we identify a combination of pathogenic pathways that culminate in MIS-C and may inform treatment.


Subject(s)
Autoimmunity , COVID-19/complications , Systemic Inflammatory Response Syndrome/immunology , Adaptive Immunity , Adolescent , Biomarkers/metabolism , COVID-19/genetics , COVID-19/immunology , COVID-19/metabolism , Case-Control Studies , Child , Child, Preschool , Cohort Studies , Cytokine Release Syndrome/immunology , Female , Humans , Infant , Inflammation/immunology , Male , Mucocutaneous Lymph Node Syndrome/genetics , Mucocutaneous Lymph Node Syndrome/immunology , Mucocutaneous Lymph Node Syndrome/metabolism , Neutrophil Activation , Proteomics , RNA-Seq , Receptors, Antigen, B-Cell/genetics , Severity of Illness Index , Systemic Inflammatory Response Syndrome/genetics , Systemic Inflammatory Response Syndrome/metabolism
16.
J Clin Invest ; 131(20)2021 10 15.
Article in English | MEDLINE | ID: covidwho-1470547

ABSTRACT

BACKGROUNDMultisystem inflammatory syndrome in children (MIS-C) is a rare but potentially severe illness that follows exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Kawasaki disease (KD) shares several clinical features with MIS-C, which prompted the use of intravenous immunoglobulin (IVIG), a mainstay therapy for KD. Both diseases share a robust activation of the innate immune system, including the IL-1 signaling pathway, and IL-1 blockade has been used for the treatment of both MIS-C and KD. The mechanism of action of IVIG in these 2 diseases and the cellular source of IL-1ß have not been defined.METHODSThe effects of IVIG on peripheral blood leukocyte populations from patients with MIS-C and KD were examined using flow cytometry and mass cytometry (CyTOF) and live-cell imaging.RESULTSCirculating neutrophils were highly activated in patients with KD and MIS-C and were a major source of IL-1ß. Following IVIG treatment, activated IL-1ß+ neutrophils were reduced in the circulation. In vitro, IVIG was a potent activator of neutrophil cell death via PI3K and NADPH oxidase, but independently of caspase activation.CONCLUSIONSActivated neutrophils expressing IL-1ß can be targeted by IVIG, supporting its use in both KD and MIS-C to ameliorate inflammation.FUNDINGPatient Centered Outcomes Research Institute; NIH; American Asthma Foundation; American Heart Association; Novo Nordisk Foundation; NIGMS; American Academy of Allergy, Asthma and Immunology Foundation.


Subject(s)
COVID-19/complications , Immunoglobulins, Intravenous/therapeutic use , Mucocutaneous Lymph Node Syndrome/immunology , Mucocutaneous Lymph Node Syndrome/therapy , Systemic Inflammatory Response Syndrome/immunology , Systemic Inflammatory Response Syndrome/therapy , COVID-19/blood , COVID-19/immunology , COVID-19/therapy , Case-Control Studies , Cell Death/immunology , Cell Lineage/immunology , Child , Child, Preschool , Fas Ligand Protein/immunology , Female , Humans , Infant , Interleukin-1beta/antagonists & inhibitors , Interleukin-1beta/blood , Leukocyte Count , Male , Mucocutaneous Lymph Node Syndrome/blood , Neutrophil Activation , Neutrophils/classification , Neutrophils/immunology , Neutrophils/pathology , Systemic Inflammatory Response Syndrome/blood
17.
EBioMedicine ; 72: 103615, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1466279

ABSTRACT

BACKGROUND: Most children and youth develop mild or asymptomatic disease during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, a very small number of patients suffer severe Coronavirus induced disease 2019 (COVID-19). The reasons underlying these different outcomes remain unknown. METHODS: We analyzed three different cohorts: children with acute infection (n=550), convalescent children (n=138), and MIS-C (multisystem inflammatory syndrome in children, n=42). IgG and IgM antibodies to the spike protein of SARS-CoV-2, serum-neutralizing activity, plasma cytokine levels, and the frequency of circulating Follicular T helper cells (cTfh) and plasmablasts were analyzed by conventional methods. FINDINGS: Fifty-eight percent of the children in the acute phase of infection had no detectable antibodies at the time of sampling while a seronegative status was found in 25% and 12% of convalescent and MIS-C children, respectively. When children in the acute phase of the infection were stratified according disease severity, we found that contrasting with the response of children with asymptomatic, mild and moderate disease, children with severe COVID-19 did not develop any detectable response. A defective antibody response was also observed in the convalescent cohort for children with severe disease at the time of admission. This poor antibody response was associated to both, a low frequency of cTfh and a high plasma concentration of inflammatory cytokines. INTERPRETATION: A weak and delayed kinetic of antibody response to SARS-CoV-2 together with a systemic pro-inflammatory profile characterize pediatric severe COVID-19. Because comorbidities are highly prevalent in children with severe COVID-19, further studies are needed to clarify their contribution in the weak antibody response observed in severe disease. FUNDING: National Agency for Scientific and Technological Promotion from Argentina (IP-COVID-19-0277 and PMO-BID-PICT2018-2548).


Subject(s)
Antibodies, Viral/blood , Antibody Formation , COVID-19/complications , COVID-19/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Systemic Inflammatory Response Syndrome/immunology , Argentina , COVID-19/blood , Child , Child, Preschool , Cytokines/blood , Female , Humans , Infant , Male , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/blood
18.
Med Sci Monit ; 27: e935005, 2021 Oct 11.
Article in English | MEDLINE | ID: covidwho-1464039

ABSTRACT

Recent studies on the pathogenesis and clinical spectrum of human disease following infection with the new human pathogen, SARS-CoV-2, have identified the varied presentations and sequelae of COVID-19. Acute 'cytokine storm' in severe COVID-19 results in multiorgan damage due to vascular hyperpermeability, edema, and hypercoagulation. The long-term consequences of infection from SARS-CoV-2 include long COVID. or post-COVID syndrome, and multisystem inflammatory syndrome in children (MIS-C). Several case reports of multisystem inflammatory syndrome in adults (MIS-A) have shown the presentation at more than four weeks after initial infection with SARS-CoV-2 in adults more than 21 years of age. In September 2021, a published systematic review of the literature identified 221 patients with MIS-A, representing the most comprehensive clinical study to date. MIS-A occurs in the post-acute COVID-19 period. The pathogenesis may involve a dysregulated antibody-mediated immune response, similar to MIS-C. Therefore, patients with MIS-A may respond to supportive therapies that control hyperinflammation. This Editorial aims to describe MIS-A and discuss COVID-19 as a spectrum of hyperinflammatory disease in terms of severity, extent, duration, and patient age.


Subject(s)
COVID-19/complications , Systemic Inflammatory Response Syndrome/etiology , COVID-19/genetics , COVID-19/immunology , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/genetics , Cytokine Release Syndrome/immunology , Humans , Systemic Inflammatory Response Syndrome/genetics , Systemic Inflammatory Response Syndrome/immunology
19.
Nat Immunol ; 22(11): 1452-1464, 2021 11.
Article in English | MEDLINE | ID: covidwho-1454797

ABSTRACT

There is limited understanding of the viral antibody fingerprint following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children. Herein, SARS-CoV-2 proteome-wide immunoprofiling of children with mild/moderate or severe coronavirus disease 2019 (COVID-19) versus multisystem inflammatory syndrome in children versus hospitalized control patients revealed differential cytokine responses, IgM/IgG/IgA epitope diversity, antibody binding and avidity. Apart from spike and nucleocapsid, IgG/IgA recognized epitopes in nonstructural protein (NSP) 2, NSP3, NSP12-NSP14 and open reading frame (ORF) 3a-ORF9. Peptides representing epitopes in NSP12, ORF3a and ORF8 demonstrated SARS-CoV-2 serodiagnosis. Antibody-binding kinetics with 24 SARS-CoV-2 proteins revealed antibody parameters that distinguish children with mild/moderate versus severe COVID-19 or multisystem inflammatory syndrome in children. Antibody avidity to prefusion spike correlated with decreased illness severity and served as a clinical disease indicator. The fusion peptide and heptad repeat 2 region induced SARS-CoV-2-neutralizing antibodies in rabbits. Thus, we identified SARS-CoV-2 antibody signatures in children associated with disease severity and delineate promising serodiagnostic and virus neutralization targets. These findings might guide the design of serodiagnostic assays, prognostic algorithms, therapeutics and vaccines in this important but understudied population.


Subject(s)
COVID-19 Serological Testing/methods , COVID-19/complications , COVID-19/immunology , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/immunology , Adolescent , Antibodies, Neutralizing/metabolism , Antibodies, Viral/metabolism , COVID-19/diagnosis , Child , Child, Preschool , Disease Progression , Epitopes/metabolism , Female , Hospitalization , Humans , Immunity, Humoral , Immunoglobulin A/metabolism , Immunoglobulin G/metabolism , Immunoglobulin M/metabolism , Male , Prognosis , Proteome , Severity of Illness Index , Systemic Inflammatory Response Syndrome/diagnosis
20.
Int Immunopharmacol ; 101(Pt B): 108217, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1446737

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new type of coronavirus causing coronavirus 2019 (COVID-19) that was first observed in Wuhan, China, in Dec. 2019. An inflammatory immune response targeting children appeared during the pandemic, which was associated with COVID-19 named multisystem inflammatory syndrome in children (MIS-C). Characteristics of MIS-C include the classic inflammation findings, multi-organ dysfunction, and fever as the cardinal feature. Up to now, no specific therapy has been identified for MIS-C. Currently, considerable progress has been obtained in the MIS-C treatment by cell therapy, specially Mesenchymal stem cells (MSCs). Unique properties have been reported for MSCs, such as various resources for purification of cell, high proliferation, self-renewal, non-invasive procedure, tissue regenerator, multidirectional differentiation, and immunosuppression. As indicated by a recent clinical research, MSCs have the ability of reducing disease inflammation and severity in children with MIS-C. In the present review study, the benefits and characteristics of MSCs and exosomes are discussed for treating patients with MIS-C.


Subject(s)
COVID-19/complications , Immunotherapy , Mesenchymal Stem Cell Transplantation , Systemic Inflammatory Response Syndrome/therapy , Animals , COVID-19/genetics , COVID-19/immunology , COVID-19/therapy , Humans , Mesenchymal Stem Cells/immunology , Systemic Inflammatory Response Syndrome/genetics , Systemic Inflammatory Response Syndrome/immunology
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