Severe COVID-19 and Multisystem Inflammatory Syndrome in Children in Children and Adolescents

Treatment of multisystem inflammatory syndrome in children

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), a relatively uncommon but severe pediatric complication, is associated with coronavirus disease 2019 (COVID-19). A variety of treatment approaches, including intravenous immunoglobulins (IVIGs), glucocorticoids (GCs) and biologic agents, such as anakinra and infliximab, have been described for the management of COVID-19-related MIS-C. Anticoagulant therapy is also important. However, a well-developed treatment system has not been established, and many issues remain controversial. Several recently published articles related to the treatment of MIS-C have been released. Hence, in this review, we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and systematically.

DATA SOURCES

We reviewed the literature on the treatment of MIS-C through 20 September 2023. The PubMed/Medline, Web of Science, EMBASE, and Cochrane Library databases were searched with the combination of the terms "multisystem inflammatory syndrome", "MIS-C", "PIMS-TS", "therapy", "treatment", "drug", "IVIG", "GCs", "intravenous immunoglobulin", "corticosteroids", "biological agent", and "aspirin".

RESULTS

The severity of MIS-C varies, and different treatment schemes should be used according to the specific condition. Ongoing research and data collection are vital to better understand the pathophysiology and optimal management of MIS-C.

CONCLUSIONS

MIS-C is a disease involving multiple systems and has great heterogeneity. With the accumulation of additional experience, we have garnered fresh insights into its treatment strategies. However, there remains a critical need for greater standardization in treatment protocols, alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols. Supplementary file1 (MP4 208044 kb).

Severe pediatric COVID-19: a review from the clinical and immunopathophysiological perspectives

BACKGROUND

Coronavirus disease 2019 (COVID-19) tends to have mild presentations in children. However, severe and critical cases do arise in the pediatric population with debilitating systemic impacts and can be fatal at times, meriting further attention from clinicians. Meanwhile, the intricate interactions between the pathogen virulence factors and host defense mechanisms are believed to play indispensable roles in severe COVID-19 pathophysiology but remain incompletely understood.

DATA SOURCES

A comprehensive literature review was conducted for pertinent publications by reviewers independently using the PubMed, Embase, and Wanfang databases. Searched keywords included "COVID-19 in children", "severe pediatric COVID-19", and "critical illness in children with COVID-19".

RESULTS

Risks of developing severe COVID-19 in children escalate with increasing numbers of co-morbidities and an unvaccinated status. Acute respiratory distress stress and necrotizing pneumonia are prominent pulmonary manifestations, while various forms of cardiovascular and neurological involvement may also be seen. Multiple immunological processes are implicated in the host response to COVID-19 including the type I interferon and inflammasome pathways, whose dysregulation in severe and critical diseases translates into adverse clinical manifestations. Multisystem inflammatory syndrome in children (MIS-C), a potentially life-threatening immune-mediated condition chronologically associated with COVID-19 exposure, denotes another scientific and clinical conundrum that exemplifies the complexity of pediatric immunity. Despite the considerable dissimilarities between the pediatric and adult immune systems, clinical trials dedicated to children are lacking and current management recommendations are largely adapted from adult guidelines.

CONCLUSIONS

Severe pediatric COVID-19 can affect multiple organ systems. The dysregulated immune pathways in severe COVID-19 shape the disease course, epitomize the vast functional diversity of the pediatric immune system and highlight the immunophenotypical differences between children and adults. Consequently, further research may be warranted to adequately address them in pediatric-specific clinical practice guidelines.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

Pediatric COVID-19 in Argentina: a comprehensive analysis of disease and economic burden through official data and a systematic literature review

Background

Limited data are available on the clinical impact and economic burden of COVID-19 in the pediatric population in Argentina. We aimed to estimate the disease and economic burden of COVID-19 on children and adolescents.

Methods

We analyzed official national databases and conducted a supplemental systematic review of the published literature with meta-analysis in children aged 0-18. The period of interest was from March 2020 to August 2021, before the introduction of vaccination in this age group as a national strategic plan. In addition, we used a cost of illness analysis to estimate the direct medical costs associated with COVID-19. All costs are reported in US dollars 2023.

Results

A total of 450,503 confirmed COVID-19 cases and 180 multisystem inflammatory syndrome (MIS-C) were reported in Argentina in the study period. Fourteen observational clinical studies were identified. The meta-analyses of severity level from hospital patients showed that according to different studies 15%-28% of cases were asymptomatic, 68%-88% were mild or moderate, and 3%-10% were severe or critical. About 28% of children had an underlying disease. In addition, the estimated economic burden associated with COVID-19 was 80 million dollars and 4 million dollars corresponded to MISC.

Conclusion

Significant impact of COVID-19 on the healthcare system and substantial economic implications for the pediatric population in Argentina were identified. The findings should help policymakers to make informed decisions and allocate resources effectively.

Overview of COVID-19 Infection, Treatment, and Prevention in Children

Coronavirus disease 2019 (COVID-19), caused by the novel respiratory virus-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-was declared a global pandemic by the World Health Organization on 11 March 2020. Since then, substantial gains have been made in our understanding of COVID-19 epidemiology, disease presentation, and management. While children tend to have less severe disease courses compared to adults, children can still develop severe COVID-19 infections, particularly in those with underlying medical conditions such as obesity, chronic lung disease, or prematurity. In addition, children are at risk of severe complications of COVID-19 infection, such as multisystem inflammatory syndrome in children (MIS-C) or long COVID. The case definitions of MIS-C and long COVID have continued to evolve with the increased understanding of these new entities; however, improved methods of diagnosis and determination of the optimal management are still needed. Furthermore, with the continued circulation of SARS-CoV-2 variants, there remains a need for clinicians to remain up-to-date on the latest treatment and prevention options. The purpose of this review is to provide an evidence-based review of what we have learned about COVID-19 in children since the start of the pandemic and how best to counsel children and their families on the best methods of prevention.

Review of pediatric emergency care and the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) pandemic posed new challenges in health care delivery for patients of all ages. These included inadequate personal protective equipment, workforce shortages, and unknowns related to a novel virus. Children have been uniquely impacted by COVID-19, both from the system of care and socially. In the initial surges of COVID-19, a decrease in pediatric emergency department (ED) volume and a concomitant increase in critically ill adult patients resulted in re-deployment of pediatric workforce to care for adult patients. Later in the pandemic, a surge in the number of critically ill children was attributed to multisystem inflammatory syndrome in children. This was an unexpected complication of COVID-19 and further challenged the health care system. This article reviews the impact of COVID-19 on the entire pediatric emergency care continuum, factors affecting ED care of children with COVID-19 infection, including availability of vaccines and therapeutics approved for children, and pediatric emergency medicine workforce innovations and/or strategies. Furthermore, it provides guidance to emergency preparedness for optimal delivery of care in future health-related crises.

Emerging infectious diseases, focus on infection prevention, environmental survival and germicide susceptibility: SARS-CoV-2, Mpox, and Candida auris

BACKGROUND

New and emerging infectious diseases continue to represent a public health threat. Emerging infectious disease threats include pathogens increasing in range (eg, Mpox), zoonotic microbes jumping species lines to cause sustained infections in humans via person-to-person transmission (SARS-CoV-2) and multidrug-resistant pathogens (eg, Candida auris).

MATERIALS AND METHODS

We searched the published English literature and reviewed the selected articles on SARS-CoV-2, Mpox, and Candida auris with a focus on environmental survival, contamination of the patient's hospital environment, susceptibility of the pathogen to antiseptics and disinfectants and infection prevention recommendations.

RESULTS

All three pathogens (ie, SARS-CoV-2, Mpox, and Candida auris) can survive on surfaces for minutes to hours and for Mpox and C auris for days. Currently available antiseptics (eg, 70%-90% alcohol hand hygiene products) are active against SARS-CoV-2, Mpox and C auris. The U.S Environmental Protection Agency provides separate lists of surface disinfectants active against SARS-CoV-2, Mpox, and C auris.

DISCUSSION

The risk of environment-to-patient transmission of SARS-CoV-2, Mpox and Candida auris, is very low, low-moderate and high, respectively. In the absence of appropriate patient isolation and use of personal protection equipment, the risk of patient-to-health care provider transmission of SARS-CoV-2, Mpox, and C auris is high, moderate and low, respectively.

CONCLUSIONS

Appropriate patient isolation, use of personal protective equipment by health care personnel, hand hygiene, and surface disinfection can protect patients and health care personnel from acquiring SARS-CoV-2, Mpox, and C auris from infected patients.

Clinical Presentation and Management of Multisystem Inflammatory Syndrome in Children With COVID-19: A Systematic Review

Multisystem inflammatory syndrome in children (MIS-C) is a relatively new syndrome associated with coronavirus disease 2019 (COVID-19) that is characterized by a severe clinical course compared to pediatric COVID-19. This review aimed to compile the available evidence on the clinical presentation and management of MIS-C in children with COVID-19. During this systematic review, a comprehensive search was performed in the following databases: PubMed, Embase, Medline, Google Scholar, Cochrane, and Scopus, using predetermined search terms, such as Medical Subject Headings (MeSH) and keywords to find relevant studies on the MIS-C. Relevant data were extracted, and the quality of the studies was evaluated using suitable methods. The collected findings were synthesized and discussed in the study. The World Health Organization's (WHO) definition of MIS-C was the most favored due to its precision and inclusiveness. MIS-C primarily affected children aged 6-12 years, with male predominance. MIS-C involves a range of systems, including gastrointestinal, cardiovascular, hematologic, mucocutaneous, and respiratory. Radiographic findings revealed cardiovascular abnormalities, solid visceral organ involvement, and bowel abnormalities, reflecting a systemic inflammatory process. Laboratory investigations unveiled elevated inflammatory markers, neutrophil activation, release of extracellular traps in vessels, elevated procalcitonin, hyponatremia, hypoalbuminemia, low hemoglobin, and thrombocytopenia. The inflammatory markers and autoantibody profiles are essential in differentiating MIS-C from COVID-19. The preferred treatment primarily involves immunomodulatory therapies like intravenous immunoglobulin (IVIG), glucocorticoids, and interleukin-6 or 1RA inhibitors or a combination of those. In severe cases, extracorporeal membrane oxygenation (ECMO) and mechanical ventilation are necessary, leading to reduced mortality and quick recovery. This review found that the average hospital stay was seven days, and most discharged children fully recovered within seven days. MIS-C is a life-threatening post-COVID-19 condition and involves multiple systems due to systemic inflammation, with elevated inflammation markers. Recognition of multisystem involvement is crucial, and prompt identification and multidisciplinary treatment are vital for optimal outcomes.

Considerations in Children and Adolescents Related to Coronavirus Disease 2019 (COVID-19)

Pediatric post-acute sequelae of SARS-CoV-2 (PASC) or "long COVID" are a complex multisystemic disease that affects children's physical, social, and mental health. PASC has a variable presentation, time course, and severity and can affect children even with mild or asymptomatic acute COVID-19 symptoms. Screening for PASC in children with a history of SARS-CoV-2 infection is important for early detection and intervention. A multifaceted treatment approach and utilization of multidisciplinary care, if available, are beneficial in managing the complexities of PASC. Lifestyle interventions, physical rehabilitation, and mental health management are important treatment approaches to improve pediatric PASC patients' quality of life.

Multisystem inflammatory syndrome in children: A dysregulated autoimmune disorder following COVID-19

Multisystem inflammatory syndrome in children (MIS-C) is a dysregulated autoimmune-mediated illness in genetically susceptible patients following COVID-19 with an interval of 2-6 weeks. The median age of patients with MIS-C is 6-11 years. Most common manifestations are involvement of gastrointestinal tract, cardiovascular system, hematological system, and mucocutaneous system. Respiratory tract, neurological system, musculoskeletal system, and kidney are less frequently affected. Mucocutaneous manifestations and coronary artery abnormalities characteristic for Kawasaki disease (KD) may be observed in a significant proportion of MIS-C patients that may make the differential diagnosis be difficult for some patients, especially in the post-pandemic era. The mortality rate is 1-3%. Management and prognosis of MIS-C are similar to that of KD. MIS-C and KD may share a common pathogenic process. Based on the observation of MIS-C-like illness in uninfected neonates, i.e. multisystem inflammatory syndrome in neonates, both MIS-C and KD may be a consequence of dysregulated, over-exaggerated humoral immune responses triggered by a specific infectious agent.

A cursed goodbye kiss from severe acute respiratory syndrome-coronavirus-2 to its pediatric hosts: multisystem inflammatory syndrome in children

PURPOSE OF REVIEW

We aimed to summarize a novel disease called multisystem inflammatory syndrome in children (MIS-C), which develops several weeks after a severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) illness.

RECENT FINDINGS

Given the rarity of the disease, the question of why a minority of children develop MIS-C is not known. Certain intrinsic susceptibility factors in the host have been described. In addition to hyperinflammation induced by the innate and acquired immune cells, evidence of molecular mimicry was presented for the disease pathogenesis. As there is an increasing number of infected individuals and mass vaccination schedules, concerns regarding the usefulness of the existing diagnostic criteria sets raised.

SUMMARY

Although children are likely to have a milder COVID-19 course compared with adults, MIS-C as a postinfectious and life-threatening complication was reported in the pediatric age. After 2 years of the disease definition, optimal treatment regimes, effective preventive measures, and long-term outcomes are still debated.

The relationship between chronic immune response and neurodegenerative damage in long COVID-19

In the past two years, the world has faced the pandemic caused by the severe acute respiratory syndrome 2 coronavirus (SARS-CoV-2), which by August of 2022 has infected around 619 million people and caused the death of 6.55 million individuals globally. Although SARS-CoV-2 mainly affects the respiratory tract level, there are several reports, indicating that other organs such as the heart, kidney, pancreas, and brain can also be damaged. A characteristic observed in blood serum samples of patients suffering COVID-19 disease in moderate and severe stages, is a significant increase in proinflammatory cytokines such as interferon-α (IFN-α), interleukin-1β (IL-1β), interleukin-2 (IL-2), interleukin-6 (IL-6) and interleukin-18 (IL-18), as well as the presence of autoantibodies against interferon-α (IFN-α), interferon-λ (IFN-λ), C-C motif chemokine ligand 26 (CCL26), CXC motif chemokine ligand 12 (CXCL12), family with sequence similarity 19 (chemokine (C-C motif)-like) member A4 (FAM19A4), and C-C motif chemokine ligand 1 (CCL1). Interestingly, it has been described that the chronic cytokinemia is related to alterations of blood-brain barrier (BBB) permeability and induction of neurotoxicity. Furthermore, the generation of autoantibodies affects processes such as neurogenesis, neuronal repair, chemotaxis and the optimal microglia function. These observations support the notion that COVID-19 patients who survived the disease present neurological sequelae and neuropsychiatric disorders. The goal of this review is to explore the relationship between inflammatory and humoral immune markers and the major neurological damage manifested in post-COVID-19 patients.

The Gut Microbiome of Children during the COVID-19 Pandemic

The gut microbiome has been shown to play a critical role in maintaining a healthy state. Dysbiosis of the gut microbiome is involved in modulating disease severity and potentially contributes to long-term outcomes in adults with COVID-19. Due to children having a significantly lower risk of severe illness and limited sample availability, much less is known about the role of the gut microbiome in children with COVID-19. It is well recognized that the developing gut microbiome of children differs from that of adults, but it is unclear if this difference contributes to the different clinical presentations and complications. In this review, we discuss the current knowledge of the gut microbiome in children with COVID-19, with gut microbiome dysbiosis being found in pediatric COVID-19 but specific taxa change often differing from those described in adults. Additionally, we discuss possible mechanisms of how the gut microbiome may mediate the presentation and complications of COVID-19 in children and the potential role for microbial therapeutics.

Nutraceuticals for Complementary Treatment of Multisystem Inflammatory Syndrome in Children: A Perspective from Their Use in COVID-19

Multisystem inflammatory syndrome in children (MIS-C) has been widely reported in some children diagnosed with SARS-CoV-2. Clinical signs of MIS-C are manifested at 2 to 4 weeks after SARS-CoV-2 infection, where elevated biomarkers of inflammation and cardiac dysfunction are the hallmark of this syndrome when infection or exposure to SARS-CoV-2 has been confirmed. However, after two years of acknowledgment, MIS-C treatment is still under research to reach safety and effectiveness in the acute phase in children. Therefore, in this review, we discuss the potential use of natural compounds with antioxidant and anti-inflammatory effects to reduce collateral damage caused by hyperinflammation in MIS-C pathology for new research in treatment and interventions.

Efficacy of sildenafil and high-dose anakinra in an MIS-C patient with pulmonary vasculitis: A case report

Multisystem inflammatory syndrome in children (MIS-C) is a newly identified clinical entity still not very well known in terms of epidemiology, pathogenesis, and long-term outcome. Pulmonary involvement with acute respiratory failure is an unusual life-threatening complication of MIS-C, often a reason for admission to the pediatric intensive care unit (PICU) and the use of mechanical ventilation. We present a case of a 7-year-old male patient, previously healthy, hospitalized for MIS-C, treated with intravenous immunoglobulins (IVIG), high dose methylprednisolone, and anakinra. After 2 days of the aforementioned therapy, the patient presented with hypoxia (SatO₂: 85% in ambient air room) and breathing difficulties. A chest computed tomography (CT) scan showed the presence of multiple bilateral basal parenchymal thickening and small basal pleural effusion and an arterial blood gas analysis revealed severe hypoxia (PaO₂/FiO₂ ratio, 170 mmHg). Because of a worsening of respiratory distress, the patient was transferred to the PICU, where invasive mechanical ventilation and a continuous infusion of anakinra (12 mg/kg/day) were started. An echocardiogram was performed, which showed an increase in pulmonary pressure (40 mmHg) with normal heart ejection fraction (55%), and the hypothesis of pulmonary vasculitis involving the pulmonary arterioles was made. Therefore, therapy with sildenafil (0.15 mg/kg/day) was promptly set up, with an immediate improvement of the clinical picture of respiratory failure, reduction of pulmonary pressure (23 mmHg), and subsequent extubation at 36 h with a regular clinical course until discharge. As far as we know, our case represents the first report of pulmonary vasculitis in an MIS-C patient. The use of sildenafil and high-dose continuous anakinra may represent a rescue therapy in cases of MIS-C with pulmonary vasculitis or with difficulty in extubation, allowing a short-term hospitalization in intensive care and improving the long-term outcome in these patients.