Endothelial Dysfunction as a Component of Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome in Children With Shock.

TRIAL REGISTRATION: NCT04420468. OBJECTIVES: Severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children is frequently associated with shock; endothelial involvement may be one of the underlying mechanisms. We sought to describe endothelial dysfunction during multisystem inflammatory syndrome in children with shock and then assess the relationship between the degree of endothelial involvement and the severity of shock. DESIGN: Observational study. SETTING: A PICU in a tertiary hospital. PATIENTS: Patients aged under 18 (n = 28) with severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children and shock, according to the Centers for Disease Control and Prevention criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Correlations between endothelial marker levels and shock severity were assessed using Spearman coefficient. The median (interquartile range) age was 9 years (7.5-11.2 yr). Sixteen children presented with cardiogenic and distributive shock, 10 presented with cardiogenic shock only, and two presented with distributive shock only. The median left ventricular ejection fraction, troponin level, and lactate level were, respectively, 40% (35-45%), 261 ng/mL (131-390 ng/mL), and 3.2 mmol/L (2-4.2 mmol/L). Twenty-five children received inotropes and/or vasopressors; the median Vasoactive and Inotropic Score was 8 (5-28). Plasma levels of angiopoietin-2 (6,426 pg/mL [2,814-11,836 pg/mL]), sE-selectin (130,405 pg/mL [92,987-192,499 pg/mL]), von Willebrand factor antigen (344% [288-378%]), and the angiopoietin-2/angiopoietin-1 ratio (1.111 [0.472-1.524]) were elevated and significantly correlated with the Vasoactive and Inotropic Score (r = 0.45, p = 0.016; r = 0.53, p = 0.04; r = 0.46, p = 0.013; and r = 0.46, p = 0.012, respectively). CONCLUSIONS: Endothelial dysfunction is associated with severe acute respiratory syndrome coronavirus 2-related multisystem inflammatory syndrome in children with shock and may constitute one of the underlying mechanisms.

Association of Intravenous Immunoglobulins Plus Methylprednisolone vs Immunoglobulins Alone With Course of Fever in Multisystem Inflammatory Syndrome in Children.

Importance: Multisystem inflammatory syndrome in children (MIS-C) is the most severe pediatric disease associated with severe acute respiratory syndrome coronavirus 2 infection, potentially life-threatening, but the optimal therapeutic strategy remains unknown. Objective: To compare intravenous immunoglobulins (IVIG) plus methylprednisolone vs IVIG alone as initial therapy in MIS-C. Design, Setting, and Participants: Retrospective cohort study drawn from a national surveillance system with propensity score-matched analysis. All cases with suspected MIS-C were reported to the French National Public Health Agency. Confirmed MIS-C cases fulfilling the World Health Organization definition were included. The study started on April 1, 2020, and follow-up ended on January 6, 2021. Exposures: IVIG and methylprednisolone vs IVIG alone. Main Outcomes and Measures: The primary outcome was persistence of fever 2 days after the introduction of initial therapy or recrudescence of fever within 7 days, which defined treatment failure. Secondary outcomes included a second-line therapy, hemodynamic support, acute left ventricular dysfunction after first-line therapy, and length of stay in the pediatric intensive care unit. The primary analysis involved propensity score matching with a minimum caliper of 0.1. Results: Among 181 children with suspected MIS-C, 111 fulfilled the World Health Organization definition (58 females [52%]; median age, 8.6 years [interquartile range, 4.7 to 12.1]). Five children did not receive either treatment. Overall, 3 of 34 children (9%) in the IVIG and methylprednisolone group and 37 of 72 (51%) in the IVIG alone group did not respond to treatment. Treatment with IVIG and methylprednisolone vs IVIG alone was associated with lower risk of treatment failure (absolute risk difference, -0.28 [95% CI, -0.48 to -0.08]; odds ratio [OR], 0.25 [95% CI, 0.09 to 0.70]; P = .008). IVIG and methylprednisolone therapy vs IVIG alone was also significantly associated with lower risk of use of second-line therapy (absolute risk difference, -0.22 [95% CI, -0.40 to -0.04]; OR, 0.19 [95% CI, 0.06 to 0.61]; P = .004), hemodynamic support (absolute risk difference, -0.17 [95% CI, -0.34 to -0.004]; OR, 0.21 [95% CI, 0.06 to 0.76]), acute left ventricular dysfunction occurring after initial therapy (absolute risk difference, -0.18 [95% CI, -0.35 to -0.01]; OR, 0.20 [95% CI, 0.06 to 0.66]), and duration of stay in the pediatric intensive care unit (median, 4 vs 6 days; difference in days, -2.4 [95% CI, -4.0 to -0.7]). Conclusions and Relevance: Among children with MIS-C, treatment with IVIG and methylprednisolone vs IVIG alone was associated with a more favorable fever course. Study interpretation is limited by the observational design.

Acute myocarditis and multisystem inflammatory emerging disease following SARS-CoV-2 infection in critically ill children.

BACKGROUND: A recent increase in children admitted with hypotensive shock and fever in the context of the COVID-19 outbreak requires an urgent characterization and assessment of the involvement of SARS-CoV-2 infection. This is a case series performed at 4 academic tertiary care centers in Paris of all the children admitted to the pediatric intensive care unit (PICU) with shock, fever and suspected SARS-CoV-2 infection between April 15th and April 27th, 2020. RESULTS: 20 critically ill children admitted for shock had an acute myocarditis (left ventricular ejection fraction, 35% (25-55); troponin, 269 ng/mL (31-4607)), and arterial hypotension with mainly vasoplegic clinical presentation. The first symptoms before PICU admission were intense abdominal pain and fever for 6 days (1-10). All children had highly elevated C-reactive protein (> 94 mg/L) and procalcitonin (> 1.6 ng/mL) without microbial cause. At least one feature of Kawasaki disease was found in all children (fever, n = 20, skin rash, n = 10; conjunctivitis, n = 6; cheilitis, n = 5; adenitis, n = 2), but none had the typical form. SARS-CoV-2 PCR and serology were positive for 10 and 15 children, respectively. One child had both negative SARS-CoV-2 PCR and serology, but had a typical SARS-CoV-2 chest tomography scan. All children but one needed an inotropic/vasoactive drug support (epinephrine, n = 12; milrinone, n = 10; dobutamine, n = 6, norepinephrine, n = 4) and 8 were intubated. All children received intravenous immunoglobulin (2 g per kilogram) with adjuvant corticosteroids (n = 2), IL 1 receptor antagonist (n = 1) or a monoclonal antibody against IL-6 receptor (n = 1). All children survived and were afebrile with a full left ventricular function recovery at PICU discharge. CONCLUSIONS: Acute myocarditis with intense systemic inflammation and atypical Kawasaki disease is an emerging severe pediatric disease following SARS-CoV-2 infection. Early recognition of this disease is needed and referral to an expert center is recommended. A delayed and inappropriate host immunological response is suspected. While underlying mechanisms remain unclear, further investigations are required to target an optimal treatment.