SARS-CoV-2-Related Inflammatory Multisystem Syndrome in Children: Different or Shared Etiology and Pathophysiology as Kawasaki Disease?

Evaluation of the Association Between Coronary Artery Aneurysms and Concomitant Infection in Patients With Kawasaki Disease

We analyzed the relationship between recovery from coronary artery aneurysms (CAAs) and concurrent infections in patients with Kawasaki disease (KD). The estimated median time of aneurysm persistence between patients with and without infections was compared using Kaplan-Meier survival analyses. Risk factors associated with persistent CAAs at 2 years were identified using multivariable analyses. Co-infection was confirmed in 20.5% (106/518) of patients diagnosed with KD. No significant differences regarding treatment or coronary artery outcome were identified between patients with and without infections. The estimated median time of aneurysm persistence was higher in the co-infected group (9 vs. 6 months). A maximum Z-score ≥ 4.00 at 1 month had 78% sensitivity and 83% specificity in predicting CAAs without recovery within 1 year of onset, whereas the predictability was higher within 2 years of onset, with a Z-score ≥ 4.88 (sensitivity, 92%; specificity, 91%). Concomitant infections did not affect the response to treatment or coronary artery outcomes in patients with KD.

The relationship between Mycoplasma and Kawasaki disease in pediatric patients: An updated systematic review and meta-analysis

Objectives

This study aimed to clarify the relationship between Mycoplasma pneumoniae (M. pneumoniae) and Kawasaki disease by conducting an updated systemic review and meta-analysis of published studies.

Materials and methods

Studies mentioning M. pneumoniae and Kawasaki disease before October 2022 were included in this meta-analysis. The pooled prevalence was calculated, and the log odds ratio in the random effects model was applied to estimate the pooled prevalence of M. pneumoniae infection in pediatric patients with Kawasaki disease. In addition, the clinical parameters, such as hemoglobin and erythrocyte sedimentation rate, were analyzed. Six studies with a total of 1,859 pediatric patients with Kawasaki disease were enrolled. The focused outcome was the pooled prevalence and clinical parameters.

Results

The pooled prevalence of M. pneumoniae infection was statistically significant in pediatric patients with Kawasaki disease. In addition, the values of hemoglobin and erythrocyte sedimentation rate were significantly different between M. pneumoniae-infected and non-M. pneumoniae-infected patients with Kawasaki disease. Other clinical parameters were not significantly different between M. pneumoniae-infected and non-M. pneumoniae-infected patients with Kawasaki disease.

Conclusion

The results suggest that M. pneumoniae infection is significantly prevalent in pediatric patients with Kawasaki disease. The lower values of hemoglobin and erythrocyte sedimentation rate in M. pneumoniae-infected patients with Kawasaki disease might be needed to investigate further.

Cardiovascular Manifestations of Multisystem Inflammatory Syndrome in Children: A Single-Center Bulgarian Study

Background and objectives: Multisystem inflammatory syndrome in children (MIS-C) poses challenges to the healthcare system, especially with frequent heart involvement. The current retrospective observational study aims to summarize the type and degree of cardiovascular involvement in children with MISC and to find possible associations between laboratory, inflammatory, and imaging abnormalities and the predominant clinical phenotype using a cluster analysis. Material and methods: We present a retrospective observational single-center study including 51 children meeting the MIS-C criteria. Results: Fifty-three percent of subjects presented with at least one sign of cardiovascular involvement (i.e., arterial hypotension, heart failure, pericardial effusion, myocardial dysfunction, pericarditis without effusion, myocarditis, coronaritis, palpitations, and ECG abnormalities). Acute pericarditis was found in 30/41 of the children (73%) assessed using imaging: 14/30 (46.7%) with small pericardial effusion and 16/30 (53.3%) without pericardial effusion. The levels of CRP were significantly elevated in the children with pericarditis (21.6 ± 13 mg/dL vs. 13.9 ± 11 mg/dL, p = 0.035), and the serum levels of IL-6 were higher in the children with small pericardial effusion compared to those without (191 ± 53 ng/L vs. 88 ± 27 ng/L, p = 0.041). Pericarditis with detectable pericardial effusion was significantly more frequent in the female vs. male subjects, 72% vs. 30% (p = 0.007). The hierarchical clustering analysis showed two clusters: Cluster 1 includes the children without cardiovascular symptoms, and Cluster 2 generalizes the MIS-C children with mild and severe cardiovascular involvement, combining pericarditis, myocarditis, heart failure, and low blood pressure. Also, subjects from Cluster 2 displayed significantly elevated levels of fibrinogen (5.7 ± 0.3 vs. 4.6 ± 0.3, p = 0.03) and IL-6 (158 ± 36 ng/mL vs. 66 ± 22 ng/mL, p = 0.032), inflammatory markers suggestive of a cytokine storm. Conclusions: Our results confirm that children with oligosymptomatic MIS-C or those suspected of long COVID-19 should be screened for possible cardiological involvement.

COVID-19 as a polymorphic inflammatory spectrum of diseases: a review with focus on the brain

There appear to be huge variations and aberrations in the reported data in COVID-19 2 years now into the pandemic. Conflicting data exist at almost every level and also in the reported epidemiological statistics across different regions. It is becoming clear that COVID-19 is a polymorphic inflammatory spectrum of diseases, and there is a wide range of inflammation-related pathology and symptoms in those infected with the virus. The host's inflammatory response to COVID-19 appears to be determined by genetics, age, immune status, health status and stage of disease. The interplay of these factors may decide the magnitude, duration, types of pathology, symptoms and prognosis in the spectrum of COVID-19 disorders, and whether neuropsychiatric disorders continue to be significant. Early and successful management of inflammation reduces morbidity and mortality in all stages of COVID-19.

Emerging Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome Associated With COVID-19 in Children

Multisystem inflammatory syndrome in children (MIS-C) has emerged as a rare delayed hyperinflammatory response to SARS-CoV-2 infection and causes severe morbidity in the pediatric age group. Although MIS-C shares many clinical similarities to Kawasaki disease (KD), important differences in epidemiologic, clinical, immunologic, and potentially genetic factors exist and suggest potential differences in pathophysiology and points to be explored and explained. Epidemiologic features include male predominance, peak age of 6 to12 years, and specific racial or ethnicity predilections. MIS-C is characterized by fever, prominent gastrointestinal symptoms, mucocutaneous manifestations, respiratory symptoms, and neurologic complaints, and patients often present with shock. Cardiac complications are frequent and include ventricular dysfunction, valvular regurgitation, pericardial effusion, coronary artery dilation and aneurysms, conduction abnormalities, and arrhythmias. Emerging evidence regarding potential immunologic mechanisms suggest that an exaggerated T-cell response to a superantigen on the SARS-CoV-2 spike glycoprotein-as well as the formation of autoantibodies against cardiovascular, gastrointestinal, and endothelial antigens-are major contributors to the inflammatory milieu of MIS-C. Further studies are needed to determine both shared and distinct immunologic pathway(s) that underlie the pathogenesis of MIS-C vs both acute SARS-CoV-2 infection and KD. There is evidence to suggest that the rare risk of more benign mRNA vaccine-associated myopericarditis is outweighed by a reduced risk of more severe MIS-C. In the current review, we synthesize the published literature to describe associated factors and potential mechanisms regarding an increased risk of MIS-C and cardiac complications, provide insights into the underlying immunologic pathophysiology, and define similarities and differences with KD.

Impact of congenital heart disease on outcomes among pediatric patients hospitalized for COVID-19 infection

BACKGROUND

COVID-19 infection is generally regarded as an acute self-limiting illness in children, but it can cause significant morbidity and mortality in both healthy and high-risk children. There are limited data on the outcomes of children with congenital heart disease (CHD) and COVID-19. This study aimed to examine the risks of mortality, in-hospital cardiovascular and non-cardiovascular complications in this patient population.

METHODS

We analyzed data from hospitalized pediatric patients from 2020 using the nationally representative National Inpatient Sample (NIS). Children hospitalized for COVID-19 were included, and weighted data were used to compare in-hospital mortality and morbidities between children with and without CHD.

RESULTS

Out of 36,690 children admitted with a diagnosis of COVID-19 infection(ICD-10 code:U07.1 and B97.29) during calendar year 2020, 1240 (3.4%) had CHD. The risk of mortality in children with CHD was not significantly higher than those without CHD(1.2% vs. 0.8%, p = 0.50), with adjusted OR (aOR) of 1.7 (95% CI: 0.6-5.3). Tachyarrhythmias and heart block were more likely in CHD children with an aOR of 4.2 (95% CI: 1.8-9.9) and aOR of 5.0 (95% CI: 2.4-10.8), respectively. Similarly, respiratory failure [aOR = 2.0 (1.5-2.8)], respiratory failure requiring non-invasive mechanical ventilation [aOR = 2.7 (1.4-5.2)] and invasive mechanical ventilation [aOR = 2.6 (1.6-4.0)], and acute kidney injury [aOR = 3.4 (2.2-5.4)] were all significantly higher among patients with CHD. Median length of hospital stay in children with CHD was longer than those without CHD [5 days (IQR: 2-11) vs. 3 days (IQR: 2-5), p = < 0.001].

CONCLUSIONS

Children with CHD hospitalized with COVID-19 infection were at increased risk of serious cardiovascular and non-cardiovascular adverse clinical outcomes. They also had increased length of hospital stay and utilization of healthcare resources.

Differentiation of COVID-19-Associated Multisystem Inflammatory Syndrome From Kawasaki Disease With the Use of Cardiac Biomarkers

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) after COVID-19 shares clinical similarities to Kawasaki disease (KD). We sought to determine whether cardiac biomarker levels differentiate MIS-C from KD and their association with cardiac involvement.

METHODS

Subjects included 38 MIS-C patients with confirmed prior COVID-19 and 32 prepandemic and 38 contemporaneous KD patients with no evidence of COVID-19. Patient, clinical, echocardiographic, electrocardiographic, and laboratory data timed within 72 hours of cardiac biomarker assessment were abstracted. Groups were compared, and regression analyses were used to determine associations between biomarker levels, diagnosis and cardiac involvement, adjusting for clinical factors.

RESULTS

MIS-C patients had fewer KD clinical features, with more frequent shock, intensive care unit admission, inotrope requirement, and ventricular dysfunction, with no difference regarding coronary artery involvement. Multivariable regression analysis showed that both higher N-terminal pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (TnI) were associated with MIS-C vs KD, after adjusting for significant covariates. Receiver operating characteristic curves for diagnosis showed that any detectable TnI greater than 10 ng/L was predictive of MIS-C vs KD with 91% sensitivity and 76% specificity. NT-proBNP > 2000 ng/L predicted MIS-C vs KD with 82% sensitivity and 82% specificity. Higher TnI but not NT-proBNP was associated with lower LV ejection fraction. Neither biomarker was associated with coronary artery involvement.

CONCLUSIONS

Positive TnI and higher NT-proBNP may differentiate MIS-C from KD, which may become more relevant as evidence of prior COVID-19 becomes more challenging to determine. Cardiac biomarkers may have limited associations with cardiac involvement in this setting.

Management of Multisystem Inflammatory Syndrome in Children: Decision-Making Regarding a New Condition in the Absence of Clinical Trial Data

Multisystem inflammatory syndrome in children (MIS-C) is a new illness that evolved during the COVID-19 pandemic with initial reports of severe disease including use of extracorporeal membrane oxygenation and death. Institutions rapidly assembled task forces to develop treatment algorithms. At the national/international levels, collaboratives and associations assembled consensus writing groups to draft guidelines. These guidelines and algorithms were initially on the basis of expert opinion and small case series. Some groups used the Delphi approach, and the resultant guidelines often mimicked those for other conditions that resembled MIS-C, like Kawasaki disease (KD). For instance, intravenous immunoglobulin (IVIG), a known effective treatment for KD, was recommended for MIS-C. Early in the pandemic many favoured IVIG over steroids as first-line therapy. As evidence evolved so did some guidelines, which now endorse the dual use of IVIG with steroids as first-line therapy. In contrast, withholding immunotherapy became an option for some MIS-C patients with mild symptoms. Herein, we review guidelines and discuss the evidence informing early recommendations, how this has evolved, the role and limitations of expert opinion and observational data, and the importance of leveraging existing research infrastructures, such as the intensive care unit collaborative (Overcoming COVID-19 surveillance registry), and the International Kawasaki Disease Registry. Finally, we discuss strategies to rapidly develop, deploy, and adapt clinical trials evaluating the treatment of such rare conditions in children, which might include alternatives to conventional clinical trial design. The emergence of MIS-C during the COVID-19 pandemic has highlighted unmet needs regarding research of a new condition.

Aseptic meningitis in multisystem inflammatory syndrome in children associated with coronavirus disease 2019: a case report

BACKGROUND

As the coronavirus disease 2019 infections are still ongoing, there is an increasing number of case reports and case series with various manifestations of life-threatening multisystem inflammatory syndrome in children . Our case aims to remind all providers to scrutinize for clinical manifestations, including neurological symptoms, which may mimic aseptic meningitis.

CASE PRESENTATION

A 5-year-old Albanian male child with obesity was admitted to the pediatric intensive care unit due to persistent fever, headache, vomiting, abdominal pain, mucocutaneous manifestations, and fatigue. Initial laboratory results revealed high level of inflammatory markers, including C-reactive protein of 156.8 mg/l, erythrocyte sedimentation rate of 100 mm/hour, procalcitonin of 13.84, leukocytosis with neutrophilia, and lymphopenia. Liver and renal functions, and capillary blood electrolytes (Na, K, Ca), were also altered. Cerebrospinal fluid was slightly turbid, with a white blood cell count of 128/mm3 (80% mononuclear cells and 20% polymorphonuclear), consistent with aseptic meningitis. The clinical presentation with prolonged fever, multiorgan dysfunction, and elevated inflammatory markers, with no plausible alternative diagnosis, matches the case definition of multisystem inflammatory syndrome in children. Combining corticosteroid methylprednisolone with intravenous immunoglobulin was effective.

CONCLUSIONS

Apart from the most common presentation of multisystem organ dysfunction, neurological manifestations of multisystem inflammatory syndrome in children such as aseptic meningitis, may be present as an immune response post-viral to coronavirus disease 2019. Given the rapid deterioration of children with multisystem inflammatory syndrome, early treatment with immunoglobulins and corticosteroids should be considered.

Left ventricular assist device implantation following multisystem inflammatory syndrome in children due to SARS-CoV-2

Multisystem inflammatory syndrome in children (MIS‐C) is rare, however, severe hyperinflammatory condition in children generally weeks after acute SARS‐CoV‐2 infection. A subset of MIS‐C patients is presented with severe heart failure. We hereby report 8‐year‐old girl presenting acute severe left ventricular failure. Various medical treatments including inotropic agents and drugs related to SARS‐CoV‐2 infection and MIS‐C were applied. However, venoarterial extracorporeal membrane oxygenation (ECMO) was needed to be performed. Due to unsuccessful attempts for ECMO weaning, left ventricular assist device was implanted to the patient with temporary right ventricular support from ECMO.

Kawasaki disease in Colombia: A systematic review and contrast with multisystem inflammatory syndrome in children associated with COVID-19

Introduction

Materials and methods

Results

Conclusions

Cellular, Antibody and Cytokine Pathways in Children with Acute SARS-CoV-2 Infection and MIS-C-Can We Match the Puzzle?

The newly identified strain of the Coronaviridae family called severe acute respiratory syndrome (SARS-CoV-2) recently became the most significant health threat for adults and children. Some main predictors of severe clinical course in patients with SARS-CoV-2 infection are age and concomitant health conditions. Therefore, the proper evaluation of SARS-CoV-2-specific immunity is urgently required to understand and predict the spectrum of possible clinical phenotypes and recommend vaccination options and regimens in children. Furthermore, it is critical to characterize the nature of SARS-CoV-2-specific immune responses in children following asymptomatic infection and COVID-19 and other related conditions such as multisystem inflammatory syndrome (MIS-C), para-infectious and late postinfectious consequences. Recent studies involving children revealed a variety of cytokines, T cells and antibody responses in the pathogenesis of the disease. Moreover, different clinical scenarios in children were observed-asymptomatic seroprevalence, acute SARS-CoV-2 infection, and rarely severe COVID-19 with typical cytokine storm, MIS-C, long COVID-19, etc. Therefore, to gain a better clinical view, adequate diagnostic criteria and treatment algorithms, it is essential to create a realistic picture of the immunological puzzle of SARS-CoV-2 infection in different age groups. Finally, it was demonstrated that children may exert a potent and prolonged adaptive anti-SARS-CoV-2 immune response, with significant cross-reactions against other human Corona Viruses, that might contribute to disease sparing effect in this age range. However, the immunopathology of the virus has to be elucidated first.

Outpatient monitoring of patients with multisystem inflammatory syndrome (MIS-C): A mini review

INTRODUCTION

As we learn more about the novel multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 infection, the protocols for long-term follow-up have evolved and only some of these protocols have been published. Here, we review the current literature on follow-up guidelines in MIS-C patients.

METHODS

We conducted a PUBMED search of all articles published on "MIS-C" and the term "follow-up" between 2020 and 2022. Inclusion criteria were that (1) the study was an observational study or case series, and (2) the study population included pediatric population who met the diagnostic criteria for MIS-C.

RESULTS

There were 206 publications on MIS-C and follow-up in the last 2 years with 11 studies that fit the inclusion criteria. These papers were representing 11 different centers and encompassed a total of 343 participants. Seven of the 11 studies had participants follow-up with their cardiologist within 1 month of discharge. Between 12% and 62% of patients within each study had depressed left ventricular ejection fraction (LVEF) at admission. At the initial follow-up visit, five studies showed a normal LVEF in all patients while the other seven studies showed 2%-13% patients continuing to have depressed LVEF. In eight of the 11 studies, 9%-52% of patients had coronary artery dilation at admission. At their initial follow-up visit, 3%-28% of patients continued to have coronary artery dilation.

CONCLUSION

There is some institutional variation in the outpatient follow-up protocols in patients diagnosed with MIS-C. A standardized follow-up guidelines might be helpful to monitor long-term prognosis of these patients.

OUP accepted manuscript

Multisystem inflammatory syndrome in children (MIS-C) can complicate infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but differences in the immune responses during MIS-C compared to coronavirus disease 2019 (COVID-19) are poorly understood. We longitudinally compared the amounts and avidity of plasma anti-nucleocapsid (N) and spike (S) antibodies, phenotypes of B cells, and numbers of virus-specific antibody-secreting cells in circulation of children hospitalized with COVID-19 (n = 10) and with MIS-C (n = 12). N-specific immunoglobulin G (IgG) was higher early after presentation for MIS-C than COVID-19 patients and avidity of N- and S-specific IgG at presentation did not mature further during follow-up as it did for COVID-19. Both groups had waning proportions of B cells in circulation and decreasing but sustained production of virus-specific antibody-secreting cells for months. Overall, B-cell responses were similar, but those with MIS-C demonstrated a more mature antibody response at presentation compared to COVID-19, suggesting a postinfectious entity.

Atlas of circulating immune cells in Kawasaki disease

Increasing evidence shows that the pathogenesis of Kawasaki disease (KD) is caused by abnormal and unbalanced innate and adaptive immune responses. However, the changes in and functions of adaptive immune cells in the peripheral blood of subjects with KD remain controversial. In this study, three different methods, CIBERSORT, Immune Cell Abundance Identifier (ImmuCellAI), and immune cell markers, were used to evaluate the proportions and abundances of immune cells in eight KD datasets (GSE9863, GSE9864, GSE18606, GSE63881, GSE68004, GSE73461, GSE73463, and GSE64486; a total of 1,251 samples). Compared with those in normal controls and convalescent KD samples, the proportions and abundances of innate immune cells such as neutrophils, monocytes, and macrophages in acute KD peripheral blood samples were significantly increased, while those of adaptive immune cells such as B and T cells were significantly decreased. The change tendencies of these immune cells were similar to those observed in other febrile illnesses but were more significant. However, in the coronary artery tissues of patients with convalescent KD, adaptive immune cells, especially B cells and CD8+ T cell subsets, were significantly increased. This result suggests that adaptive immune cells can be selectively recruited from peripheral blood into the coronary arteries. In addition, we found that elevated neutrophils in peripheral blood could be used as a biomarker to assist in the differential diagnosis of KD, but we did not find immune cells that could accurately predict intravenousimmunoglobulin (IVIG) responses in multiple datasets.

Learning about Kawasaki disease from COVID-19 and the Multisystem Inflammatory Syndrome in Children

PURPOSE OF REVIEW

Multisystem Inflammatory Syndrome in Children (MIS-C) is a novel syndrome that has appeared in the wake of the severe acute respiratory syndrome coronavirus -2 pandemic, with features that overlap with Kawasaki disease (KD). As a result, new interest and focus have arisen in KD, and specifically mechanisms of the disease.

RECENT FINDINGS

A major question in the literature on the nature of MIS-C is if, and how, it may be related to KD. This has been explored using component analysis type studies, as well as other unsupervised analysis, as well as direct comparisons. At present, the answer to this question remains opaque, and several studies have interpreted their findings in opposing ways. Studies seem to suggest some relationship, but that MIS-C and KD are not the same syndrome.

SUMMARY

Study of MIS-C strengthens the likelihood that KD is a postinfectious immune response, and that perhaps multiple infectious agents or viruses underlie the disease. MIS-C and KD, while not the same disease, could plausibly be sibling disorders that fall under a larger syndrome of postacute autoimmune febrile responses to infection, along with Kawasaki shock syndrome.

Kawasaki Disease Hospitalizations in the United States 2016-2020: A Comparison of Before and During the Coronavirus Disease 2019 Era

BACKGROUND

Kawasaki disease (KD) is an acute vasculitis of young children. A comparison of US hospitalization rates and epidemiologic features of KD in 2020 to those of precoronavirus disease years has yet to be reported.

METHODS

Using a large, inpatient database, we conducted a retrospective cohort study and analyzed data for patients with (1) diagnosis coding for KD, (2) IV immunoglobulin treatment administered during hospitalization and (3) discharge date between January 1, 2016, and December 30, 2020. Severe cases were defined as those requiring adjunctive therapy or IV immunoglobulin-resistant therapy.

RESULTS

The annual number of KD hospitalizations were stable from 2016 to 2019 (n = 1652, 1796, 1748, 1692, respectively) but decreased in 2020 (n = 1383). KD hospitalizations demonstrated seasonal variation with an annual peak between December and April. A second peak of KD admissions was observed in May 2020. The proportion of KD cases classified as severe increased to 40% in 2020 from 33% during the years 2016-2019 (P < 0.01). Median age in years increased from 2.9 in subjects hospitalized from 2016 to 2019 to 3.2 in 2020 (P = 0.002).

CONCLUSIONS

Compared with the previous 4 years, the annual number of pediatric KD admissions decreased, and children discharged with diagnostic codes for KD in 2020 were generally older and more likely to have severe morbidity possibly reflective of misdiagnosed multisystem inflammatory syndrome in children. Clinicians should be wary of a possible rise in KD rates in the postcoronavirus disease 2019 era as social distancing policies are lifted and other viruses associated with KD return.

Current Understanding of Multisystem Inflammatory Syndrome (MIS-C) Following COVID-19 and Its Distinction from Kawasaki Disease

PURPOSE OF REVIEW

In this article, I have reviewed current reports that explore differences and similarities between multisystem inflammatory syndrome in children (MIS-C) and other known multisystem inflammatory diseases seen in children, particularly Kawasaki disease.

RECENT FINDINGS

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a human coronavirus causing the COVID-19 disease which emerged in China in December 2019 and spread rapidly to the entire country and quickly to other countries. Currently, there is a pandemic of SARS-CoV-2 infection that results in 20% of patients admitted to hospital with illness, with 3% developing intractable acute respiratory distress syndrome (ARDS) with high mortality. However, pediatric COVID-19 is still reported to be a mild disease, affecting only 8% of children. Pathogenesis in children is comparable to adults. There are suggested impaired activation of IFN-alpha and IFN regulator 3, decreased cell response causing impaired viral defense, yet the clinical course is mild, and almost all children recover from the infection without major complications. Interestingly, there is a subset of patients that develop a late but marked immunogenic response to COVID-19 and develop MIS-C. Clinical features of MIS-C resemble certain pediatric rheumatologic diseases, such as Kawasaki disease (mucocutaneous lymph node syndrome) which affects small-medium vessels. Other features of MIS-C resemble those of macrophage activation syndrome (MAS). However, recent research suggests distinct clinical and laboratory differences between MIS-C, Kawasaki disease, and MAS. Since the start of the SARS-CoV-2 pandemic, MIS-C has become the candidate for the most common cause of acquired heart disease in children.

[COVID-19 in children: SARS-CoV-2-related inflammatory multisystem syndrome mimicking Kawasaki disease]

SARS-CoV-2 pandemics is characterized by a high level of infectivity and a high mortality among adults at risk (older than 65 years, obesity, diabetes, systemic hypertension). Following a common viral pneumonia, a multisystem inflammatory syndrome sometimes occurs, including an Acute Respiratory Distress Syndrome (ARDS) carrying a high mortality. Unlike most common respiratory viruses, children seem less susceptible to SARS-CoV-2 infection and generally develop a mild disease with low mortality. However, clusters of severe shock associated with high levels of cardiac biomarkers and unusual vasoplegia requiring inotropes, vasopressors and volume loading have been recently described. Both clinical symptoms (i.e., high and persistent fever, gastrointestinal disorders, skin rash, conjunctivitis and dry cracked lips) and biological signs (e.g., elevated CRP/PCT, hyperferritinemia) resembled Kawasaki disease. In most instances, intravenous immunoglobin therapy improved the cardiac function and led to full recovery within a few days. However, adjunctive steroid therapy and sometimes biotherapy (e.g., anti-IL-1Ra, anti-IL-6 monoclonal antibodies) were often necessary. Although almost all children fully recovered within a week, some of them developed coronary artery dilation or aneurysm. Thus, a new 'Multisystem Inflammatory Syndrome associated with SARS-CoV-2' has been recently described in children and helps to better understand Kawasaki disease pathophysiology.

Kawasaki Disease Patient Stratification and Pathway Analysis Based on Host Transcriptomic and Proteomic Profiles

The aetiology of Kawasaki disease (KD), an acute inflammatory disorder of childhood, remains unknown despite various triggers of KD having been proposed. Host 'omic profiles offer insights into the host response to infection and inflammation, with the interrogation of multiple 'omic levels in parallel providing a more comprehensive picture. We used differential abundance analysis, pathway analysis, clustering, and classification techniques to explore whether the host response in KD is more similar to the response to bacterial or viral infections at the transcriptomic and proteomic levels through comparison of 'omic profiles from children with KD to those with bacterial and viral infections. Pathways activated in patients with KD included those involved in anti-viral and anti-bacterial responses. Unsupervised clustering showed that the majority of KD patients clustered with bacterial patients on both 'omic levels, whilst application of diagnostic signatures specific for bacterial and viral infections revealed that many transcriptomic KD samples had low probabilities of having bacterial or viral infections, suggesting that KD may be triggered by a different process not typical of either common bacterial or viral infections. Clustering based on the transcriptomic and proteomic responses during KD revealed three clusters of KD patients on both 'omic levels, suggesting heterogeneity within the inflammatory response during KD. The observed heterogeneity may reflect differences in the host response to a common trigger, or variation dependent on different triggers of the condition.

SARS-CoV-2-related MIS-C: A key to the viral and genetic causes of Kawasaki disease?

Multisystem inflammatory syndrome in children (MIS-C) emerged in April 2020 in communities with high COVID-19 rates. This new condition is heterogenous but resembles Kawasaki disease (KD), a well-known but poorly understood and clinically heterogenous pediatric inflammatory condition for which weak associations have been found with a myriad of viral illnesses. Epidemiological data clearly indicate that SARS-CoV-2 is the trigger for MIS-C, which typically occurs about 1 mo after infection. These findings support the hypothesis of viral triggers for the various forms of classic KD. We further suggest that rare inborn errors of immunity (IEIs) altering the immune response to SARS-CoV-2 may underlie the pathogenesis of MIS-C in some children. The discovery of monogenic IEIs underlying MIS-C would shed light on its pathogenesis, paving the way for a new genetic approach to classic KD, revisited as a heterogeneous collection of IEIs to viruses.

Multisystem inflammatory syndrome in children (MIS-C) and the coronavirus pandemic: Current knowledge and implications for public health

The coronavirus disease 2019 (COVID-19) pandemic has caused widespread mortality and morbidity. Though children are largely spared from severe illness, a novel childhood hyperinflammatory syndrome presumed to be associated with and subsequent to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has emerged with potentially severe outcomes. Multisystem inflammatory disorder in children (MIS-C) most commonly affects young, school-aged children and is characterized by persistent fever, systemic hyperinflammation, and multisystem organ dysfunction. While uncommon and generally treatable, MIS-C presents potentially life-altering medical sequelae, complicated by a dearth of information regarding its etiology, pathophysiology, and long-term outcomes. The severity of MIS-C may warrant the need for increased awareness and continued COVID-19 mitigation efforts, particularly until potential factors conferring a predisposition to MIS-C can be clarified through additional research. Well-informed guidelines will be critical as the school year progresses. In this article, current knowledge on MIS-C is reviewed and the potential implications of this novel syndrome are discussed from a public health perspective.

Potential link between SARS-CoV-2 and Kawasaki disease: importance of dentists for the diagnosis

Kawasaki disease (KD) is a vasculitis with predilection for coronary arteries. Due to a lack of reliable confirmatory laboratory tests, the diagnosis of KD is based on a characteristic pattern of clinical findings that appear in a typical temporal sequence. The diagnostic criteria have been periodically modified and the American Heart Association has proposed the most recent guidelines for its diagnosis. However, patients may have incomplete or atypical forms of KD and diagnosis can often be difficult. Because oropharyngeal manifestations are a common and important feature for diagnosing KD and recent studies have hypothesized a possible association between KD and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in this review we highlight the importance of dentists in the diagnosis of KD and its potential association with SARS-CoV-2.

Deep immune profiling of MIS-C demonstrates marked but transient immune activation compared to adult and pediatric COVID-19

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8+ T cells that correlated with the use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct from one another and implicate CD8+ T cells in the clinical presentation and trajectory of MIS-C.

Immune cartography of macrophage activation syndrome in the COVID-19 era

A hyperinflammatory 'cytokine storm' state termed macrophage activation syndrome (MAS), culminating from a complex interplay of genetics, immunodeficiency, infectious triggers and dominant innate immune effector responses, can develop across disparate entities including systemic juvenile idiopathic arthritis (sJIA) and its counterpart adult-onset Still disease (AOSD), connective tissue diseases, sepsis, infection, cancers and cancer immunotherapy. Classifying MAS using the immunological disease continuum model, with strict boundaries that define the limits of innate and adaptive immunity, at one boundary is MAS with loss of immune function, as occurs in the 'perforinopathies' and some cases of sJIA-AOSD. Conversely, at the other boundary, immune hypersensitivity with gain of immune function in MHC class II-associated sJIA-AOSD and with chimeric antigen receptor (CAR) T cell therapy also triggers MAS. This provides a benchmark for evaluating severe inflammation in some patients with COVID-19 pneumonia, which cripples primary type I interferon immunity and usually culminates in a lung-centric 'second wave' cytokine-driven alveolitis with associated immunothrombosis; this phenomenon is generally distinct from MAS but can share features with the proposed 'loss of immune function' MAS variant. This loss and gain of function MAS model offers immune cartography for a novel mechanistic classification of MAS with therapeutic implications.

Multisystem inflammatory syndrome in children rose and fell with the first wave of the COVID-19 pandemic in France

AIM

This study determined the influence of the COVID-19 pandemic on the occurrence of multisystem inflammatory syndrome in children (MIS-C) and compared the main characteristics of MIS-C and Kawasaki disease (KD).

METHODS

We included patients aged up to 18 years of age who were diagnosed with MIS-C or KD in a paediatric university hospital in Paris from 1 January 2018 to 15 July 2020. Clinical, laboratory and imaging characteristics were compared, and new French COVID-19 cases were correlated with MIS-C cases in our hospital.

RESULTS

There were seven children with MIS-C, from 6 months to 12 years of age, who were all positive for the virus that causes COVID-19, and 40 virus-negative children with KD. Their respective characteristics were as follows: under 5 years of age (14.3% vs. 85.0%), paediatric intensive care unit admission (100% vs. 10.0%), abdominal pain (71.4% vs. 12.5%), myocardial dysfunction (85.7% vs. 5.0%), shock syndrome (85.7% vs. 2.5%) and mean and standard deviation C-reactive protein (339 ± 131 vs. 153 ± 87). There was a strong lagged correlation between the rise and fall in MIS-C patients and COVID-19 cases.

CONCLUSION

The rise and fall of COVID-19 first wave mirrored the MIS-C cases. There were important differences between MIS-C and KD.

Cutaneous Manifestations of COVID-19: A Systematic Review

Objective: Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a pandemic. Although pulmonary health has been the primary focus of studies during the early days of COVID-19, development of a comprehensive understanding of this emergent disease requires knowledge of all possible disease manifestations in affected patients. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-compliant review focuses on cutaneous manifestations reported in COVID-19 patients. Approach: Literature review was conducted using the PubMed database to examine various cutaneous manifestations related to the SARS-CoV-2 infection. Published articles (n = 56) related to search criteria from the onset of the COVID-19 pandemic to June 30, 2020, were included. The primary literature articles included in this study were mainly from France, Spain, Italy, and the United Kingdom. Results: Unique to many other symptoms of COVID-19, its cutaneous manifestations have been found in people of all age groups, including children. The cutaneous manifestations of COVID-19 are varied and include maculopapular, chilblain-like, urticarial, vesicular, livedoid, and petechial lesions. In addition, rashes are common in multisystem inflammatory syndrome in children, a new and serious health condition that shares symptoms with Kawasaki disease and is likely related to COVID-19. In addition, personal protective equipment-related skin wounds are of serious concern since broken cutaneous barriers can create an opening for potential COVID-19 infections. Innovation and Conclusion: As this virus continues to spread silently, mainly through asymptomatic carriers, an accurate and rapid identification of these cutaneous manifestations may be vital to early diagnosis and lead to possible better prognosis in COVID-19 patients. This systematic review and photo atlas provide a detailed analysis of the skin pathologies related to COVID-19. Study of these cutaneous manifestations and their pathogenesis, as well their significance in human health will help define COVID-19 in its entirety, which is a prerequisite to its effective management.

Abdominal Imaging Findings in Critically Ill Children With Multisystem Inflammatory Syndrome Associated With COVID-19

We report findings on abdominal imaging in critically ill children admitted with MIS-C. On sonography, hepatomegaly, nephromegaly, gallbladder wall edema, ascites, intestinal inflammation and mesenteric lymphadenopathy were seen, while CT showed fluid-filled small bowel loops, mural thickening of the terminal ileum, diffuse lymphadenopathy, and moderate ascites.

Discriminating Multisystem Inflammatory Syndrome in Children Requiring Treatment from Common Febrile Conditions in Outpatient Settings

OBJECTIVES

To examine whether patients with multisystem inflammatory syndrome in children (MIS-C) demonstrated well-defined clinical features distinct from other febrile outpatients, given the difficulties of seeing acute care visits during the severe acute respiratory syndrome coronavirus 2 pandemic and the risks associated with both over- and underdiagnosis of MIS-C.

STUDY DESIGN

This case-controlled study compared patients diagnosed with and treated for MIS-C at a large urban children's hospital with patients evaluated for fever at outpatient acute care visits during the peak period of MIS-C. Symptomatology and available objective data were extracted. Comparisons were performed using t tests with corrections for multiple comparisons, and multivariable logistic regression to obtain ORs.

RESULTS

We identified 44 patients with MIS-C between April 16 and June 10, 2020. During the same period, 181 pediatric patients were evaluated for febrile illnesses in participating outpatient clinics. Patients with MIS-C reported greater median maximum reported temperature height (40°C vs 38.9, P < .0001), and increased frequency of abdominal pain (OR 12.5, 95% CI [1.65-33.24]), neck pain (536.5, [2.23-129,029]), conjunctivitis (31.3, [4.6-212.8]), oral mucosal irritation (11.8, [1.4-99.4]), extremity swelling or rash (99.9, [5-1960]), and generalized rash (7.42, [1.6-33.2]). Patients with MIS-C demonstrated lower absolute lymphocyte (P < .0001) and platelet counts (P < .05) and greater C-reactive protein concentrations (P < .001).

CONCLUSIONS

Patients treated for MIS-C due to concern for potential cardiac injury show combinations of features distinct from other febrile patients seen in outpatient clinics during the same period.

The "Golden Hours" Algorithm For the Management of the Multisystem Inflammatory Syndrome in Children (MIS-C)

The global concern of increasing number of children presenting with multisystem inflammatory syndrome in children (MIS-C) related to the coronavirus disease (COVID-19) has escalated the need for a case-oriented clinical approach that provides timely diagnosis and management. The aim of this study is to share our experience in managing 64 MIS-C patients of North African ethnicity guided by a risk-based algorithm. Sixty-four patients met the inclusion criteria, 19 (30%) patients were categorized as mild and moderate risk groups and cared for in an isolation ward and 45 patients who belonged to the high-risk group (70%) were admitted to the pediatric intensive care unit (PICU). Positive laboratory evidence of COVID-19 was found in 62 patients. Fever and dysfunction in 2 or more organs were confirmed in all cases (100%). Fifty patients (78%) presented with gastrointestinal symptoms, meanwhile only 10 patients (16%) had respiratory manifestations. Cardiac involvement was reported in 55 (86%) cases; hypotension and shock were found in 45 patients (70%) therein circulatory support and mechanical ventilations were needed for 45 and 13 patients respectively. Intravenous immunoglobulins (IVIG) were used for all cases and methylprednisolone was used in 60 patients (94%). Fifty-eight (91%) patients were discharged home after an average of 9 days of hospitalization. The mortality rate was 9% (6 patients). Conclusion. A single Egyptian center experience in the management of MIS-C patients guided by a proposed bed side algorithm is described. The algorithm proved to be a helpful tool for first-line responders, and helped initiate early treatment with IVIG.

Cardiac Manifestations of Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with SARS-CoV-2 Infection

Context: Multisystem inflammatory syndrome in children (MIS-C) is an emerging condition after the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, termed COVID-19. This study aimed to describe the cardiac manifestations of children diagnosed with MIS-C. Evidence Acquisition: This narrative review was conducted by searching the PubMed, Scopus, and Google Scholar databases to review MIS-C cardiac manifestations up to September 30, 2020. The demographic features, past medical history, clinical signs and symptoms, cardiac involvement, and the type of COVID-19 diagnosis confirmation were extracted. Results: In many children, MIS-C seems to be a post-infectious complication of the COVID-19 infection. This syndrome affects multiple organs and has various clinical manifestations mimicking Kawasaki disease. Patients frequently present with persistent fever, kidney injury, gastrointestinal (GI) problems, neurologic symptoms, mucosal changes, conjunctivitis, and cardiac involvement. Children with MIS are more likely to present with hypotension, shock, and cardiac dysfunction, rather than coronary artery abnormalities and arrhythmia. Children with MIS need close observation; some need to be hospitalized, and a few may need a Pediatric Intensive Care Unit (PICU) admission. Treatment currently includes anticoagulants, IV immunoglobulin, and anti-inflammatory drugs. Conclusions: As a novel syndrome associated with SARS-CoV-2 infection, MIS-C is potentially lethal. Cardiac manifestations, including coronary and myocardial involvement, are common and should be carefully identified. With prompt diagnosis and proper treatment, most children will survive, but the outcomes of the disease are unknown, so long-term follow-ups are required.

Clinical aspects for differential diagnosis of Kawasaki disease shock syndrome: a case control study

Background

Because of the absence of a specific diagnostic test and pathognomonic clinical features, physicians must rely on the presence of specific clinical criteria and laboratory data that support the diagnosis of KD. To help clinicians distinguish KD, KDSS, septic shock, and TSS earlier, we suggest differential diagnosis and treatment guideline.

Methods

Medical records of immunocompetent patients who were admitted to the pediatric department with a diagnosis of KDSS, septic shock or TSS (SS group) were retrospectively reviewed. In addition, KD patients were selected by seasonal matching to each case of KDSS patient by date of admission (± 2 weeks).

Results

There were 13 patients with KDSS, 35 patients with SS group, and 91 patients with KD. In comparison between KDSS and septic shock group, KDSS group had significantly higher rate of coronary aneurysm incidence, and higher left ventricle dysfunction rate. In comparison between KDSS and TSS, patients with KDSS had a significantly higher erythrocyte sedimentation rate (ESR) and significantly lower creatinine. Receiver operation characteristic curve revealed that the optimal ESR cut off value for determining the KDSS was 56.0 (sensitivity 75.0%, specificity of 100.0%) and the optimal creatinine cut off value for determining the TSS was 0.695 (sensitivity 76.9%, specificity 84.6%).

Conclusions

Clinical symptoms, laboratory finding, echocardiography, and culture studies can be used to differentiate KD, KDSS, septic shock and TSS.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-020-02488-w.

COVID-19 and paediatric patient involvement (cardiovascular aspects)

The majority of children with COVID-19 infections, fortunately, shows only milder symptoms. Which however has led that they are considered only for their particular transmission potential. Nevertheless, cases with Multisystem Inflammatory Syndrome in Children and Kawasaki Disease with quite specific COVID-19 involvement have been reported and should be taken seriously. In addition, there are many children with a chronic pre-existing condition such as congenital heart disease, cancer, or lung disease who may be at risk for a severe course of COVID-19 when infected. Protecting these children, and children in general, should be a top priority, as these patients will have to live the rest of their long lives with possible sequelae of COVID-19.

COVID-19 in children: Pathogenesis and current status

Background: Since its initial description in December 2019 in Wuhan, China, coronavirus disease 2019 (COVID-19) has rapidly progressed into a worldwide pandemic, which has affected millions of lives. Unlike the disease in adults, the vast majority of children with COVID-19 have mild symptoms and are largely spared from severe respiratory disease. However, there are children who have significant respiratory disease, and some may develop a hyperinflammatory response similar to that seen in adults with COVID-19 and in children with Kawasaki disease (KD), which has been termed multisystem inflammatory syndrome in children (MIS-C). Objective: The purpose of this report was to examine the current evidence that supports the etiopathogenesis of COVID-19 in children and the relationship of COVID-19 with KD and MIS-C as a basis for a better understanding of the clinical course, diagnosis, and management of these clinically perplexing conditions. Results: The pathogenesis of COVID-19 is carried out in two distinct but overlapping phases of COVID-19: the first triggered by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) itself and the second by the host immune response. Children with KD have fewer of the previously described COVID-19-associated KD features with less prominent acute respiratory distress syndrome and shock than children with MIS-C. Conclusion: COVID-19 in adults usually includes severe respiratory symptoms and pathology, with a high mortality. It has become apparent that children are infected as easily as adults but are more often asymptomatic and have milder disease because of their immature immune systems. Although children are largely spared from severe respiratory disease, they can present with a SARS-CoV-2-associated MIS-C similar to KD.

Association between SARS-CoV-2 infection and Kawasaki-like multisystem inflammatory syndrome: a retrospective matched case-control study, Paris, France, April to May 2020

We assessed the association between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and Kawasaki disease (KD)-like multisystem inflammatory syndrome in a retrospective case–control study in France. RT-PCR and serological tests revealed SARS-CoV-2 infection in 17/23 cases vs 11/102 controls (matched odds ratio: 26.4; 95% confidence interval: 6.0–116.9), indicating strong association between SARS-CoV-2 infection and KD-like illness. Clinicians should keep a high level of suspicion for KD-like illness during the COVID-19 pandemic.

Immunological Assessment of Pediatric Multisystem Inflammatory Syndrome Related to Coronavirus Disease 2019

BACKGROUND

Recently, cases of multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) have been reported worldwide. Negative polymerase chain reaction (RT-PCR) testing associated with positive serology in most of the cases suggests a postinfectious syndrome. Because the pathophysiology of this syndrome is still poorly understood, extensive virological and immunological investigations are needed.

METHODS

We report a series of 4 pediatric patients admitted to Geneva University Hospitals with persistent fever and laboratory evidence of inflammation meeting the published definition of MIS-C related to COVID-19, to whom an extensive virological and immunological workup was performed.

RESULTS

RT-PCRs on multiple anatomical compartments were negative, whereas anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglobulin A (IgA) and immunoglobulin G (IgG) were strongly positive by enzyme-linked immunosorbent assay and immunofluorescence. Both pseudoneutralization and full virus neutralization assays showed the presence of neutralizing antibodies in all children, confirming a recent infection with SARS-CoV-2. The analyses of cytokine profiles revealed an elevation in all cytokines, as reported in adults with severe COVID-19. Although differing in clinical presentation, some features of MIS-C show phenotypic overlap with hemophagocytic lymphohistiocytosis (HLH). In contrast to patients with primary HLH, our patients showed normal perforin expression and natural killer (NK) cell degranulation. The levels of soluble interleukin (IL)-2 receptor (sIL-2R) correlated with the severity of disease, reflecting recent T-cell activation.

CONCLUSION

Our findings suggest that MIS-C related to COVID-19 is caused by a postinfectious inflammatory syndrome associated with an elevation in all cytokines, and markers of recent T-cell activation (sIL-2R) occurring despite a strong and specific humoral response to SARS-CoV-2. Further functional and genetic analyses are essential to better understand the mechanisms of host-pathogen interactions.

Cardiovascular impact of COVID-19 with a focus on children: A systematic review

BACKGROUND

Since the beginning of the pandemic, coronavirus disease-2019 (COVID-19) in children has shown milder cases and a better prognosis than adults. Although the respiratory tract is the primary target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), cardiovascular involvement is emerging as one of the most significant and life-threatening complications of SARS-CoV-2 infection in adults.

AIM

To summarize the current knowledge about the potential cardiovascular involvement in pediatric COVID-19 in order to give a perspective on how to take care of them during the current pandemic emergency.

METHODS

Multiple searches in MEDLINE, PubMed were performed using the search terms "COVID-19" or "SARS-CoV-2" were used in combination with "myocardial injury" or "arrhythmia" or "cardiovascular involvement" or "heart disease" or "congenital heart disease" or "pulmonary hypertension" or "long QT" or "cardiomyopathies" or "channelopathies" or "Multisystem inflammatory system" or "PMIS" or "MIS-C" or "Pediatric multisystem inflammatory syndrome" or "myocarditis" or "thromboembolism to identify articles published in English language from January 1st, 2020 until July 31st, 2020. The websites of World Health Organization, Centers for Disease control and Prevention, and the Johns Hopkins Coronavirus Resource Center were reviewed to provide up to date numbers and infection control recommendations. Reference lists from the articles were reviewed to identify additional pertinent articles. Retrieved manuscripts concerning the subject were reviewed by the authors, and the data were extracted using a standardized collection tool. Data were subsequently analyzed with descriptive statistics. For Pediatric multisystemic inflammatory syndrome temporally associated with COVID-19 (PMIS), multiple meta-analyses were conducted to summarize the pooled mean proportion of different cardiovascular variables in this population in pseudo-cohorts of observed patients.

RESULTS

A total of 193 articles were included. Most publications used in this review were single case reports, small case series, and observational small-sized studies or literature reviews. The meta-analysis of 16 studies with size > 10 patients and with complete data about cardiovascular involvement in children with PMIS showed that PMIS affects mostly previously healthy school-aged children and adolescents presenting with Kawasaki disease-like features and multiple organ failure with a focus on the heart, accounting for most cases of pediatric COVID-19 mortality. They frequently presented cardiogenic shock (53%), ECG alterations (27%), myocardial dysfunction (52%), and coronary artery dilation (15%). Most cases required PICU admission (75%) and inotropic support (57%), with the rare need for extracorporeal membrane oxygenation (4%). Almost all of these children wholly recovered in a few days, although rare deaths have been reported (2%). Out of PMIS cases we identified 10 articles reporting sporadic cases of myocarditis, pulmonary hypertension and cardiac arrythmias in previously healthy children. We also found another 10 studies reporting patients with pre-existing heart diseases. Most cases consisted in children with severe COVID-19 infection with full recovery after intensive care support, but cases of death were also identified. The management of different cardiac conditions are provided based on current guidelines and expert panel recommendations.

CONCLUSION

There is still scarce data about the role of cardiovascular involvement in COVID-19 in children. Based on our review, children (previously healthy or with pre-existing heart disease) with acute COVID-19 requiring hospital admission should undergo a cardiac workup and close cardiovascular monitoring to identify and treat timely life-threatening cardiac complications.

Management of Multisystem Inflammatory Syndrome in Children Associated With COVID-19: A Survey From the International Kawasaki Disease Registry

BACKGROUND

Since April 2020, there have been numerous reports of children presenting with systemic inflammation, often in critical condition, and with evidence of recent infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This condition, since defined as the multisystem inflammatory syndrome in children (MIS-C), is assumed to be a delayed immune response to coronavirus disease 2019 (COVID-19), and there are frequently cardiac manifestations of ventricular dysfunction and/or coronary artery dilation.

METHODS

We surveyed the inpatient MIS-C management approaches of the members of the International Kawasaki Disease Registry across 38 institutions and 11 countries.

RESULTS

Among the respondents, 56% reported using immunomodulatory treatment for all MIS-C patients, regardless of presentation. Every respondent reported use of intravenous immunoglobulin (IVIG), including 53% administering IVIG in all patients. Steroids were most often used for patients with severe clinical presentation or lack of response to IVIG, and only a minority used steroids in all patients (14%). Acetylsalicylic acid was frequently used among respondents (91%), including anti-inflammatory and/or antiplatelet dosing. Respondents reported use of prophylactic anticoagulation, especially in patients at higher risk for venous thromboembolism, and therapeutic anticoagulation, particularly for patients with giant coronary artery aneurysms.

CONCLUSIONS

There is variation in management of MIS-C patients, with suboptimal evidence to assess superiority of the various treatments; evidence-based gaps in knowledge should be addressed through worldwide collaboration to optimize treatment strategies.

Dermatologic manifestations of COVID-19-associated multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) affects a small percentage of pediatric patients infected with COVID-19 and is characterized by fever, laboratory evidence of inflammation, multisystem involvement, and severe illness necessitating hospitalization. Skin findings are often present in these patients, and when initially compared with Kawasaki disease, they likely represent distinct phenomena and overall remain poorly characterized. In this retrospective review of 34 case reports and series, we identified cutaneous manifestations documented in 417 of 736 patients (57%) with MIS-C associated with COVID-19. “Rash” was the sole descriptor of skin findings in nearly half of patients. Case reports and smaller case series provided more detail, outlining a broad range of lesion morphologies (polymorphic, maculopapular, morbilliform, erythrodermic, urticarial, reticular, petechial, purpuric) in variable anatomic distribution. More thorough descriptions of dermatologic manifestations in patients with MIS-C are warranted to better characterize this syndrome, as they may lend important insight into pathogenic mechanisms of disease.

Cutaneous manifestations of COVID-19 in children (and adults): A virus that does not discriminate

Coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a beta coronavirus with a characteristic S-glycoprotein spike on the cell surface. Initial reports did not include cutaneous manifestations as a feature of COVID-19; however, there is a growing repertoire of reports demonstrating an array of dermatologic manifestations on the skin in children and adults. Dermatologic afflictions have been summarized into different categories several times, with the most recent analysis identifying six clinical patterns: urticaria, maculopapular-morbilliform eruption, papulovesicular exanthem, chilblain-like acral pattern, livedo reticularis-livedo racemosa pattern, and purpuric vasculitic pattern. In children, the dermatologic features appear to occur before or concomitantly with other COVID-19 manifestations. Dermatologists play a key role in diagnosing patients with COVID-19 who may present for the first time unwittingly exhibiting early signs of COVID-19. We have reviewed the current evidence on the dermatologic impact of COVID-19 in both the adult and pediatric populations.

Mucocutaneous disease and related clinical characteristics in hospitalized children and adolescents with COVID-19 and multisystem inflammatory syndrome in children

Background

Little is known about mucocutaneous disease in acutely ill children and adolescents with COVID-19 and multisystem inflammatory syndrome in children (MIS-C).

Objective

To characterize mucocutaneous disease and its relation to clinical course among hospitalized patients with COVID-19 and MIS-C.

Methods

Descriptive cohort study of prospectively and consecutively hospitalized eligible patients between May 11, 2020 and June 5, 2020.

Results

In COVID-19 patients, 4 of 12 (33%) had rash and/or mucositis, including erythema, morbilliform pattern, and lip mucositis. In MIS-C patients, 9 of 19 (47%) had rash and/or mucositis, including erythema, morbilliform, retiform purpura, targetoid and urticarial patterns, along with acral edema, lip mucositis, tongue papillitis, and conjunctivitis. COVID-19 patients with rash had less frequent respiratory symptoms, pediatric intensive care unit admission, invasive ventilation, and shorter stay versus COVID-19 patients without rash. MIS-C patients with rash had less frequent pediatric intensive care unit admission, shock, ventilation, as well as lower levels of C-reactive protein, ferritin, D-dimer, and troponin (vs MIS-C without rash). Neutrophil-to-lymphocyte ratio was similar for patients with and without rash in both groups. None of the MIS-C patients met criteria for Kawasaki disease.

Limitations

Small sample sizes.

Conclusions

Mucocutaneous disease is common among children and adolescents with COVID-19 and MIS-C. Laboratory trends observed in patients with rash may prognosticate a less severe course.

Characteristics and considerations in the medical treatment of COVID-19 in children

It is rare for children to be in serious condition or die from coronavirus disease 2019 (COVID‐19) caused by the 2019 novel coronavirus (severe acute respiratory syndrome coronavirus 2 [SARS‐CoV‐2]) except for those with underlying diseases such as chronic lung disease (including asthma), cardiovascular disease, and immunosuppressive disease. Recently, patients with hyperinflammatory shock have been identified among children who are confirmed to have or are suspected of having SARS‐CoV‐2 infection. The presenting signs and symptoms are characterized by prolonged fever, abdominal pain, and cardiac involvement without any signs of pneumonia on chest computed tomography. However, it is uncertain at this time whether SARS‐CoV‐2 infection affects this syndrome. Compared with adults, quite a few children are asymptomatic even when infected with SARS‐CoV‐2, which could make these children serious sources of infection at home or in medical institutions. Considering these characteristics, it is important to take appropriate precautions during medical examinations and perform infection control in emergency departments to save the lives of both the children and adult patients. Most healthy children are suffering from huge stress due to restrictions against going outside and school closures as social means to control infection. It is possible that children are socially isolated when they come to the emergency department, and they might require mental or social support even if they are only complaining about their physical condition. Health‐care providers are required to examine the children’s circumstances carefully and cooperate with workers in other professions appropriately.

Deep Immune Profiling of MIS-C demonstrates marked but transient immune activation compared to adult and pediatric COVID-19

Pediatric COVID-19 following SARS-CoV-2 infection is associated with fewer hospitalizations and often milder disease than in adults. A subset of children, however, present with Multisystem Inflammatory Syndrome in Children (MIS-C) that can lead to vascular complications and shock, but rarely death. The immune features of MIS-C compared to pediatric COVID-19 or adult disease remain poorly understood. We analyzed peripheral blood immune responses in hospitalized SARS-CoV-2 infected pediatric patients (pediatric COVID-19) and patients with MIS-C. MIS-C patients had patterns of T cell-biased lymphopenia and T cell activation similar to severely ill adults, and all patients with MIS-C had SARS-CoV-2 spike-specific antibodies at admission. A distinct feature of MIS-C patients was robust activation of vascular patrolling CX3CR1+ CD8 T cells that correlated with use of vasoactive medication. Finally, whereas pediatric COVID-19 patients with acute respiratory distress syndrome (ARDS) had sustained immune activation, MIS-C patients displayed clinical improvement over time, concomitant with decreasing immune activation. Thus, non-MIS-C versus MIS-C SARS-CoV-2 associated illnesses are characterized by divergent immune signatures that are temporally distinct and implicate CD8 T cells in clinical presentation and trajectory of MIS-C.

Canadian society of clinical chemists (CSCC) interim consensus guidance for testing and reporting of SARS-CoV-2 serology

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SARS-CoV-2 serology offers limited clinical utility for individuals.

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SARS-CoV-2 serology may be useful for seroprevalence studies.

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Claims regarding protective immunity or infectivity cannot be made using serology.

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Assay clinical sensitivity and specificity should approach 100%.

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Harmonized reporting of SARS-CoV-2 serology minimizes result misinterpretation.

Clinical laboratories across the world are working to validate and perform testing for SARS-CoV-2 antibodies. Herein, we present interim consensus guidance for Canadian clinical laboratories testing and reporting SARS-CoV-2 serology, with emphasis on the capabilities and limitations of these tests and recommendations for interpretative comments in an effort to achieve harmonized laboratory practices. The consensus document provides a broad overview of topics including sample type and contamination risk; kinetics of antibody response to COVID-19 and the impact on serology testing; clinical utility of SARS-CoV-2 serology testing; clinical performance of commercial laboratory-based assays commonly deployed in North America; recommendations for interim reporting; utility of SARS-CoV-2 antibody testing for pediatric patients; and utility of point-of-care testing. The information is based on the current literature and is subject to change as additional information becomes available.

Multisystem Inflammatory Syndrome Associated With COVID-19 With Neurologic Manifestations in a Child: A Brief Report

Although first considered a benign infection, recent studies have disclosed severe and potentially lethal inflammatory manifestations of COVID-19 in children. We report the case of a 4-year-old child with a post-infectious multisystem inflammatory syndrome associated with COVID-19, with a Kawasaki-like shock and prominent neurologic features, for whom a cytokine storm and reduced brain-derived neurotrophic factor were well documented.

Multisystem inflammatory syndrome in children: Is there a linkage to Kawasaki disease?

Since 1967, researches have hunted for an etiology for Kawasaki Disease (KD). Meanwhile, the 2019 Coronavirus Disease (COVID-19) pandemic has produced a strange new illness termed multisystem inflammatory syndrome in children (MIS-C) and raised hopes that a cause for KD may be identified. This current review paper discusses KD and its potential connection to pediatric COVID-19 and MIS-C illness.

COVID-19-associated vasculitis and vasculopathy

The COVID-19 pandemic now totaling 13,000,000 cases and over 571,000 deaths has continued to teach the medical, scientific and lay communities about viral infectious disease in the modern era. Among the many lessons learned for the medical community is the potential for transmissibility and host infectivity of the SARS–CoV-2 virus. Moreover, it has become clear that the virus can affect any organ including the circulatory system, directly via either tissue tropism or indirectly stemming from inflammatory responses in the form of innate immunity, leukocyte debris such as cell-free DNA and histones and RNA viral particles. The following review considers COVID-19-associated vasculitis and vasculopathy as a defining feature of a virus-induced systemic disease with acute, subacute and potential chronic health implications.

Severe acute respiratory syndrome coronavirus-2: implications for blood safety and sufficiency

Background and Objective

Severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) is a novel coronavirus, first identified in China at the end of 2019 and has now caused a worldwide pandemic. In this review, we provide an overview of the implications of SARS‐CoV‐2 for blood safety and sufficiency.

Material and Method

We searched the PubMed database, the preprint sites bioRxiv and medRxiv, the websites of the World Health Organization, European Centre for Disease Prevention and Control, the US Communicable Diseases Center and monitored ProMed updates.

Results

An estimated 15%–46% of SARS‐CoV‐2 infections are asymptomatic. The reported mean incubation period is 3 to 7 days with a range of 1–14 days. The blood phase of SARS‐CoV‐2 appears to be brief and low level, with RNAaemia detectable in only a small proportion of patients, typically associated with more severe disease and not demonstrated to be infectious virus. An asymptomatic blood phase has not been demonstrated. Given these characteristics of SARS‐CoV‐2 infection and the absence of reported transfusion transmission (TT), the TT risk is currently theoretical. To mitigate any potential TT risk, but more importantly to prevent respiratory transmission in donor centres, blood centres can implement donor deferral policies based on travel, disease status or potential risk of exposure.

Conclusion

The TT risk of SARS‐CoV‐2 appears to be low. The biggest risk to blood services in the current COVID‐19 pandemic is to maintain the sufficiency of the blood supply while minimizing respiratory transmission of SARS‐CoV‐19 to donors and staff while donating blood.