Project description:While fewer cases of severe Coronavirus Disease 2019 (COVID-19) are reported globally in children, a small proportion of SARS-CoV-2 infected children develop a novel pediatric febrile entity called multisystem inflammatory syndrome in children (MIS-C) that develops 2 to 5 weeks after initial SARS-CoV-2 exposure. MIS-C primarily effects male children and children of Hispanic or black descent. MIS-C manifests as a severe and uncontrolled inflammatory response with multiorgan involvement. A hyperinflammatory state is evidenced by clinical makers of inflammation including high levels of C-reactive protein (CRP), ferritin, and D-dimers, and an increased expression of pro-inflammatory cytokines. Children often present with persistent fever, severe gastrointestinal symptoms, cardiovascular manifestations, respiratory symptoms and neurological symptoms6-11,13. Cardiovascular manifestations include hypotension, shock, cardiac dysfunction, myocarditis and pericardial effusion. In the united states, admission to the intensive care unit occurs in approximately 58% of cases. To understand disease pathogenesis of MIS-C and proteins associated with the severe form of disease we performed proteomics analysis of serum or plasma samples. We collected serum from healthy children (SARS-CoV-2 negative, n=20), mild MIS-C (non-ICU, n=5) and severe MIS-C (ICU, n = 20) patients. MIS-C definition and diagnosis was performed according to CDC guidelines. Healthy adult serum (n = 4) was also used for reference ranges quality control and we obtained plasma samples from Kawasaki Disease (KD; n=7) patients that were recruited before the Coronavirus Disease 2019 (COVID-19) pandemic.
Project description:Multisystem inflammatory syndrome in children (MIS-C) is a severe, post-infectious sequela of SARS-CoV-2 infection1,2, yet the pathophysiological mechanism connecting the infection to the broad inflammatory syndrome remains unknown. Here we leveraged a large set of samples from patients with MIS-C to identify a distinct set of host proteins targeted by patient autoantibodies including a particular autoreactive epitope within SNX8, a protein involved in regulating an antiviral pathway associated with MIS-C pathogenesis. In parallel, we also probed antibody responses from patients with MIS-C to the complete SARS-CoV-2 proteome and found enriched reactivity against a distinct domain of the SARS-CoV-2 nucleocapsid protein. The immunogenic regions of the viral nucleocapsid and host SNX8 proteins bear remarkable sequence similarity. Consequently, we found that many children with anti-SNX8 autoantibodies also have cross-reactive T cells engaging both the SNX8 and the SARS-CoV-2 nucleocapsid protein epitopes. Together, these findings suggest that patients with MIS-C develop a characteristic immune response to the SARS-CoV-2 nucleocapsid protein that is associated with cross-reactivity to the self-protein SNX8, demonstrating a mechanistic link between the infection and the inflammatory syndrome, with implications for better understanding a range of post-infectious autoinflammatory diseases.
Project description:In early 2020, at the beginning of the coronavirus disease 2019 (COVID-19) pandemic due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rare cases were reported in children and adolescents of multisystem inflammatory syndrome in children (MIS-C). MIS-C is characterized by fever, systemic inflammation, and multiorgan dysfunction and usually presents late in SARS-CoV-2 infection. Since May 2020, the Centers for Disease Control and Prevention (CDC) has recorded all reported cases of COVID-19 and MIS-C in children and adolescents in the USA. In April 2021, the American College of Rheumatology (ACR) revised its clinical guidelines for diagnosing and managing hyperinflammation and MIS-C. There are several challenges ahead for preventing, diagnosing, and managing MIS-C, particularly following the rapid emergence of new strains of SARS-CoV-2. This Editorial aims to present an update on the current status of the clinical presentation, diagnosis, and management of MIS-C and includes some updates from population studies and clinical guidelines.
Project description:MIS-C is a systemic inflammation disorder with poorly characterised immunopathological mechanisms. We compared changes in the systemic immune response in children with MIS-C (n = 12, 5-13 years) to healthy controls (n = 14, 5-15 years). Analysis was done in whole blood treated with LPS. Expression of CD11b and Toll-like receptor-4 (TLR4) in neutrophils and monocytes were analysed by flow cytometry. Serum cytokines (IL-1β, IL-2, IL-6, IL-8, IL-10, IL-Ira, TNF-α, TNF-β, IFN-Υ, VEGF, EPO and GM-CSF) and mRNA levels of inflammasome molecules (NLRP3, ASC and IL-1β) were evaluated. Subpopulations of lymphocytes (CD3+, CD19+, CD56+, CD4+, CD8+, TCR Vδ1+, TCR Vδ2+) were assessed at basal levels. Absolute counts of neutrophils and NLR were high in children with MIS-C while absolute counts of lymphocytes were low. Children with MIS-C had increased levels of IL-6, IL-10, TNF-β and VEGF serum cytokines at the basal level, and significantly increased TNF-β post-LPS, compared to controls. IL-1RA and EPO decreased at baseline and post-LPS in MIS-C patients compared to controls. The percentage of CD3+ cells, NK cells and Vδ1 was lower while B cells were higher in children with MIS-C than in controls. Dysregulated immune response in children with MIS-C was evident and may be amenable to immunomodulation.
Project description:Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following SARS-CoV-2 infection associated with intestinal manifestations. Genetic predisposition, including inborn errors of the OAS-RNAseL pathway, has been reported. We sequenced 154 MIS-C patients and utilized a novel statistical framework of gene burden analysis, "burdenMC," which identified an enrichment for rare predicted-deleterious variants in BTNL8 (OR = 4.2, 95% CI: 3.5-5.3, P < 10-6). BTNL8 encodes an intestinal epithelial regulator of Vγ4+γδ T cells implicated in regulating gut homeostasis. Enrichment was exclusive to MIS-C, being absent in patients with COVID-19 or bacterial disease. Using an available functional test for BTNL8, rare variants from a larger cohort of MIS-C patients (n = 835) were tested which identified eight variants in 18 patients (2.2%) with impaired engagement of Vγ4+γδ T cells. Most of these variants were in the B30.2 domain of BTNL8 implicated in sensing epithelial cell status. These findings were associated with altered intestinal permeability, suggesting a possible link between disrupted gut homeostasis and MIS-C-associated enteropathy triggered by SARS-CoV-2.
Project description:We defined the prevalence of neck pain, trismus, or dysphagia (28.4%) and retropharyngeal edema (2.9%) among 137 patients with multisystem inflammatory syndrome in children (MIS-c). Retropharyngeal edema or phlegmon has been documented radiologically in at least 9 children. Symptoms of neck inflammation are common in MIS-c.
Project description:Multisystem inflammatory syndrome in children (MIS-C) occurs in some children approximately 2-6 weeks following infection with SARS-CoV-2. Clinical symptoms are highly overlapping with Kawasaki disease (KD) and bacterial (DB) and viral (DV) infections, making diagnosis particularly challenging. Host whole blood transcriptomics can reveal specific combinations of host genes whose expression patterns can distinguish between disease groups of interest. We performed whole blood RNA-Sequencing of individuals with MIS-C, KD, bacterial and viral infections to identify a number of host genes that, when combined, could be used to diagnose MIS-C. This data contains processed data only. Raw data will be available via a controlled access archive.
Project description:ObjectivesTo describe the clinical presentation, phenotype and outcome of multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (Covid-19) from a tertiary care center in southern India.Methods257 children fulfilling the inclusion criteria of MIS-C were prospectively enrolled from June, 2020 to March, 2022.ResultsMedian (range) age at presentation was 6 year (35 day to 12 years). Presenting features were fever (98%), vomiting (75.8%), red eyes (63%), rashes (49%), pain abdomen (49%), shock (45.9%), lymphopenia (73%, thrombocytopenia (58.3%) and anemia (45%). 103 (39.7%) children required intensive care admission. Shock phenotype, Kawasaki-like phenotype and no specific phenotype were diagnosed in 45.9%, 44.4%, and 36.6% children, respectively. Left ventricular dysfunction (30.3%), acute kidney injury (13%), acute liver failure (17.4%), and hemophagolymphohistiocytosis (HLH) (13.6%) were the major system involvement in MIS-C. Mitral regurgitation (P=0.029), hyperechogenic coronaries (P=0.006), Left ventricular dysfunction (P=0.001) and low ejection fraction (P=0.007) were significantly associated with shock. Overall mortality was 11.7%.ConclusionKawasaki-like and shock-like presentation were common in MIS-C. Coronary abnormalities were seen in 118 (45.9%) children. Children with acute kidney injury, HLH, need for mechanical ventilation, and echocardiogram evidence of mitral regurgitation in MIS-C have a poor outcome.
Project description:Initially, the global outbreak of COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spared children from severe disease. However, after the initial wave of infections, clusters of a novel hyperinflammatory disease have been reported in regions with ongoing SARS-CoV-2 epidemics. While the characteristic clinical features are becoming clear, the pathophysiology remains unknown. Herein, we report on the immune profiles of eight Multisystem Inflammatory Syndrome in Children (MIS-C) cases. We document that all MIS-C patients had evidence of prior SARS-CoV-2 exposure, mounting an antibody response with normal isotype-switching and neutralization capability. We further profiled the secreted immune response by high-dimensional cytokine assays, which identified elevated signatures of inflammation (IL-18 and IL-6), lymphocytic and myeloid chemotaxis and activation (CCL3, CCL4, and CDCP1) and mucosal immune dysregulation (IL-17A, CCL20, CCL28). Mass cytometry immunophenotyping of peripheral blood revealed reductions of mDC1 and non-classical monocytes, as well as both NK- and T- lymphocytes, suggesting extravasation to affected tissues. Markers of activated myeloid function were also evident, including upregulation of ICAM1 and FcR1 in neutrophil and non-classical monocytes, well-documented markers in autoinflammation and autoimmunity that indicate enhanced antigen presentation and Fc-mediated responses. Finally, to assess the role for autoimmunity secondary to infection, we profiled the auto-antigen reactivity of MIS-C plasma, which revealed both known disease-associated autoantibodies (anti-La) and novel candidates that recognize endothelial, gastrointestinal and immune-cell antigens. All patients were treated with anti- IL6R antibody or IVIG, which led to rapid disease resolution tracking with normalization of inflammatory markers.
Project description:Multisystem inflammatory syndrome in children (MIS-C) is an immune-mediated complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Cardiovascular system is commonly involved. Acute heart failure (AHF) is the most severe complication of MIS-C, leading to cardiogenic shock. The aim of the study was to characterise the course of MIS-C with a focus on cardiovascular involvement, based on echocardiographic (echo) evaluation, in 498 children (median age 8.3 years, 63% boys) hospitalised in 50 cities in Poland. Among them, 456 (91.5%) had cardiovascular system involvement: 190 (48.2%) of patients had (most commonly atrioventricular) valvular insufficiency, 155 (41.0%) had contractility abnormalities and 132 (35.6%) had decreased left ventricular ejection fraction (LVEF < 55%). Most of these abnormalities improved within a few days. Analysis of the results obtained from two echo descriptions (a median of 5 days apart) revealed a >10% increase in LVEF even in children with primarily normal LVEF. Lower levels of lymphocytes, platelets and sodium and higher levels of inflammatory markers on admission were significantly more common among older children with contractility dysfunction, while younger children developed coronary artery abnormality (CAA) more often. The incidence of ventricular dysfunction might be underestimated. The majority of children with AHF improved significantly within a few days. CAAs were relatively rare. Children with impaired contractility as well as other cardiac abnormalities differed significantly from children without such conditions. Due to the exploratory nature of this study, these findings should be confirmed in further studies.