Exploring viral infections' role in Kawasaki disease onset: A study during the COVID-19 pandemic.

During the coronavirus disease 2019 (COVID-19) pandemic, known viral diseases declined in all ages. By using the current situation as a natural experiment, this study aimed to evaluate whether the change in the incidence of Kawasaki disease (KD) during the COVID-19 pandemic varies with age and whether a specific infectious disease mediates the occurrence of KD. Monthly number of KD patients were extracted from the nationwide inpatient database. Segmented regression analysis was conducted on the interrupted time series data. Additionally, causal mediation analysis was performed to examine the role of viral infections in the changes in the number of KD patients. After the first emergency declaration for COVID-19 in Japan, there was an immediate decrease in the number of KD patients per 100 000 population aged between 6 months and 4 years (immediate change = -2.66; 95% confidence interval [CI]: -5.16 to -0.16) and aged 5-15 years (immediate change = -0.26; 95% CI: -0.49 to -0.04). However, no immediate change was observed in patients under 6 months of age. In the causal mediation analysis for each viral infection, it was found that the decrease in the number of patients with KD was mediated by changes in the number of patients with pharyngoconjunctival fever and infectious gastroenteritis. The current results suggest that viral infections may be one of the etiological agents for KD, while they may not be the main cause in early infancy. Specifically, we found that adenovirus infection and gastroenteritis was closely related to the onset of KD in some areas of Japan.

Identification of Torquetenovirus Species in Patients with Kawasaki Disease Using a Newly Developed Species-Specific PCR Method.

A next-generation sequencing (NGS) study identified a very high viral load of Torquetenovirus (TTV) in KD patients. We aimed to evaluate the feasibility of a newly developed quantitative species-specific TTV-PCR (ssTTV-PCR) method to identify the etiology of KD. We applied ssTTV-PCR to samples collected from 11 KD patients and 22 matched control subjects who participated in our previous prospective study. We used the NGS dataset from the previous study to validate ssTTV-PCR. The TTV loads in whole blood and nasopharyngeal aspirates correlated highly (Spearman's R = 0.8931, p < 0.0001, n = 33), supporting the validity of ssTTV-PCR. The ssTTV-PCR and NGS results were largely consistent. However, inconsistencies occurred when ssTTV-PCR was more sensitive than NGS, when the PCR primer sequences mismatched the viral sequences in the participants, and when the NGS quality score was low. Interpretation of NGS requires complex procedures. ssTTV-PCR is more sensitive than NGS but may fail to detect a fast-evolving TTV species. It would be prudent to update primer sets using NGS data. With this precaution, ssTTV-PCR can be used reliably in a future large-scale etiological study for KD.

Prevalence of paediatric hyperinflammatory conditions in paediatric and adolescent hospitalized COVID-19 patients: a systematic review and meta-analysis.

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

Characterizing the differences between multisystem inflammatory syndrome in children and Kawasaki disease.

To characterize the new SARS-Co-V-2 related multisystem inflammatory syndrome in children (MIS-C) among Israeli children and to compare it with Kawasaki disease (KD). We compared, in two medical centers, the clinical and laboratory characteristics of MIS-C, KD and an intermediate group, which met the case definitions of both conditions. MIS-C patients were older, were more likely to be hypotensive, to have significant gastrointestinal symptoms, lymphopenia and thrombocytopenia and to have non-coronary abnormal findings in their echocardiogram. Lymphopenia was an independent predictor of MIS-C. Most of our MIS-C patients responded promptly to corticosteroid therapy. KD incidence in both centers was similar in 2019 and 2020. Although there is clinical overlap between KD and MIS-C, these are separate entities. Lymphopenia clearly differentiates between these entities. MIS-C patients may benefit from corticosteroids as first-line therapy.

The Emerging Role of Neutrophils in the Pathogenesis of Thrombosis in COVID-19.

Previous studies have shown that COVID-19 leads to thrombotic complications, which have been associated with high morbidity and mortality rates. Neutrophils are the largest population of white blood cells and play a pivotal role in innate immunity. During an infection, neutrophils migrate from circulation to the infection site, contributing to killing pathogens. This mechanism is regulated by chemokines such as IL-8. Moreover, it was shown that neutrophils play an important role in thromboinflammation. Through a diverse repertoire of mechanisms, neutrophils, apart from directly killing pathogens, are able to activate the formation of thrombi. In COVID-19 patients, neutrophil activation promotes neutrophil extracellular trap (NET) formation, platelet aggregation, and cell damage. Furthermore, neutrophils participate in the pathogenesis of endothelitis. Overall, this review summarizes recent progress in research on the pathogenesis of COVID-19, highlighting the role of the prothrombotic action of neutrophils in NET formation.

Kawasaki like illness due to COVID-19: a review of the literature.

INTRODUCTION: Viral infections have been described as triggers for Kawasaki Disease (KD), a medium vessel vasculitis that affects young children. Akin to the H1N1 pandemic in 2009, there is a similar rise in the incidence of KD in children affected with Coronavirus disease 2019 (COVID-19). Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-COV-2) has been reported to induce an exaggerated systemic inflammatory response resulting in multi-organ involvement, particularly initiated with pulmonary parenchymal damage. This review article will discuss KD-like manifestations in COVID-19 patients in the pediatric cohort. METHODOLOGY: Search terms "Kawasaki" "COVID-19" "SARS-COV-2" "PIM-TS" and "MIS-C" were used to look for relevant articles in PubMed and Google Scholar published in the last 5 years. RESULTS: There is some evidence to suggest that SARS-CoV-2 stimulates dysfunctional and hyperactive immune reactions mimicking KD in young patients. CONCLUSIONS: Therapeutic options, both investigational and repurposed, include intravenous immunoglobulins, steroids and anticoagulation. More studies are required to evaluate the effectiveness of these treatment options.

Coronavirus disease 2019 (COVID-19): A systematic review of 133 Children that presented with Kawasaki-like multisystem inflammatory syndrome.

Kawasaki-like disease (KLD) and multisystem inflammatory syndrome in children (MIS-C) are considered as challenges for pediatric patients under the age of 18 infected with coronavirus disease 2019 (COVID-19). A systematic search was performed on July 2, 2020, and updated on December 1, 2020, to identify studies on KLD/MIS-C associated with COVID-19. The databases of Scopus, PubMed, Web of Science, Embase, and Scholar were searched. The hospitalized children with a presentation of Kawasaki disease (KD), KLD, MIS-C, or inflammatory shock syndromes were included. A total number of 133 children in 45 studies were reviewed. A total of 74 (55.6%) cases had been admitted to pediatric intensive care units (PICUs). Also, 49 (36.8%) patients had required respiratory support, of whom 31 (23.3%) cases had required mechanical ventilation/intubation, 18 (13.5%) cases had required other oxygen therapies. In total, 79 (59.4%) cases had been discharged from hospitals, 3 (2.2%) had been readmitted, 9 (6.7%) had been hospitalized at the time of the study, and 9 (6.7%) patients had expired due to the severe heart failure, shock, brain infarction. Similar outcomes had not been reported in other patients. Approximately two-thirds of the children with KLD associated with COVID-19 had been admitted to PICUs, around one-fourth of them had required mechanical ventilation/intubation, and even some of them had been required readmissions. Therefore, physicians are strongly recommended to monitor children that present with the characteristics of KD during the pandemic as they can be the dominant manifestations in children with COVID-19.

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.

Guide for cardiological referral for patients with paediatric multisystemic inflammatory syndrome and Kawasaki disease associated with SARS-CoV-2 / Guía para referencia cardiológica de pacientes con síndrome inflamatorio multisistémico pediátrico y enfermedad por Kawasaki asociados al SARS-CoV-2

We present an institutional guide for a referral to the specialized care center and initial management of pediatric patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with severe manifestations of pediatric inflammatory multisystemic syndrome or symptoms similar to Kawasaki syndrome, and who must have a multidisciplinary approach to ensure adequate treatment and safety for the team of Health.

Presentamos una guía para la referencia al centro de atención especializada y el manejo inicial de pacientes pediátricos infectados por el coronavirus 2 del síndrome respiratorio agudo grave (SARS-CoV-2) con manifestaciones graves del síndrome multisistémico inflamatorio pediátrico o síntomas semejantes al síndrome de Kawasaki y que deben tener un abordaje multidisciplinario para garantizar un adecuado tratamiento y la mayor seguridad para el equipo de salud.

SARS-CoV-2 infection triggering recurrence of Kawasaki disease in a 10-year-old child.

SARS-CoV-2 infection has recently been related to a spectrum of hyper-inflammatory states in children. There is a striking similarity between these hyper-inflammatory states and Kawasaki disease (KD). We present an interesting case of KD recurrence in a 10-year-old child, who had previously developed KD at 4 years of age. His symptoms included fever, maculopapular rash and altered sensorium. Investigations showed noticeably elevated inflammatory markers, and an echocardiography revealed dilated coronary arteries. SARS-CoV-2 IgG antibodies were positive. The child responded dramatically to intravenous immunoglobulin and intravenous methylprednisolone. It is possible that SARS-CoV-2 infection triggered the recurrence of KD in this child who might have been genetically predisposed to KD.

Identification of key signaling pathways induced by SARS-CoV2 that underlie thrombosis and vascular injury in COVID-19 patients.

The SARS-CoV-2 pandemic has led to hundreds of thousands of deaths and billions of dollars in economic damage. The immune response elicited from this virus is poorly understood. An alarming number of cases have arisen where COVID-19 patients develop complications on top of the symptoms already associated with SARS, such as thrombosis, injuries of vascular system, kidney, and liver, as well as Kawasaki disease. In this review, a bioinformatics approach was used to elucidate the immune response triggered by SARS-CoV-2 infection in primary human lung epithelial and transformed human lung alveolar. Additionally, examined the potential mechanism behind several complications that have been associated with COVID-19 and determined that a specific cytokine storm is leading to excessive neutrophil recruitment. These neutrophils are directly leading to thrombosis, organ damage, and complement activation via neutrophil extracellular trap release.

Shock and Myocardial Injury in Children With Multisystem Inflammatory Syndrome Associated With SARS-CoV-2 Infection: What We Know. Case Series and Review of the Literature.

BACKGROUND: Multisystem inflammatory syndrome associated with SARS-CoV-2 infection can lead to myocardial injury and shock in children, likely the result of a severe inflammatory state, and can mimic Kawasaki disease. OBJECTIVE: To describe the characteristics of shock and myocardial injury in children with confirmed or suspeted COVID-19 during the SARS-CoV-2 pandemic in Spain, including clinical presentation, laboratory and imaging findings, treatment, disease course, and outcome. An extensive literature review is provided. METHODS: Retrospective case series including all children (age 1 month-18 years) admitted to a pediatric intensive care unit in Madrid, Spain, between March 15 and April 30, 2020 with suspected or confirmed SARS-CoV-2 infection and shock. RESULTS: Twelve previously healthy patients with shock, age 5 to 14 years, were included. All required volume resuscitation and 75% required vasoactive/inotropic support. Distributive shock was present on admission in 67% (n = 8), and 4 patients (33%) showed features of cardiogenic shock. Myocardial injury was diagnosed in 67% (n = 8) and ventricular dysfunction in 33% (n = 4). The most common symptoms on presentation were fever (100%), anorexia (100%), diarrhea (75%), and vomiting (75%). Five patients showed signs of Kawasaki disease but none met the criteria for the classic form. Laboratory findings revealed lymphopenia (83%), thrombocytopenia (83%), and increased inflammatory markers (100%). Respiratory status was not significantly impacted. Chest X-ray showed bilateral alveolar infiltrates in 7 (58%) and bilateral pneumonia in 3 (25%). COVID-19 was confirmed in 11 cases (92%). All received empirical therapy against COVID-19, thromboprophylaxis and immunomodulation. Median stay in the PICU and inpatient ward was 4.5 and 10 days, respectively. No patients died. CONCLUSION: Multisystem inflammatory syndrome in children with COVID-19 can mimic Kawasaki disease and lead to a combination of distributive and cardiogenic shock, probably secondary to a hyperinflammatory state that remains to be precisely defined. Treatment strategies include hemodynamic support, empirical therapies against COVID-19, thromboprophylaxis, and immunomodulation.

Paediatric multisystem inflammatory syndrome associated with COVID-19: filling the gap between myocarditis and Kawasaki?

Myocarditis and Kawasaki disease are common but usually distinct diseases in children. During the coronavirus pandemic (COVID-19), reports of a new form of myocarditis with clinical features of Kawasaki appeared. We investigated the place of this new disease in the spectrum encompassing Kawasaki disease and myocarditis.Thirty two consecutive children referred to our centre for a suspicion of Kawasaki or a diagnosis of myocarditis were included and eventually divided into four groups: 11 Kawasaki diseases, 6 Kawasaki syndromes (children with another diagnosis), 7 myocarditis without Kawasaki clinical feature and 7 myocarditis with incomplete Kawasaki clinical features. All were treated with immunoglobulins except those of the myocarditis group. The survival rate was 91%. The 7 children with myocarditis and clinical features of incomplete Kawasaki were all positive for SARS-CoV-2. They had a transient myocardial failure with a favourable course and none had coronary artery disease.Conclusion: Every COVID-19 child within our population had a mild to severe myocarditis and presented with fever plus two or three Kawasaki clinical features. Short-term evolution was good for these children. This new disease seems to fill the gap between isolated myocarditis and Kawasaki disease. What is Known: • A new paediatric disease close to Kawasaki disease appeared during the COVID-19 pandemic What is New: • In our population, children presented with fever, vivid Kawasaki clinical features (although the Kawasaki syndrome was always incomplete) and a myocarditis without coronary abnormalities. • The new disease fills the gap between paediatric myocarditis and Kawasaki disease but its prognosis is much better.

Pediatric Inflammatory Multisystem Syndrome: Time to Collaborate.

There is significant variability in the names and case definition of pediatric inflammatory multisystem syndrome associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Such variability leads to adverse consequences in the quest for further knowledge and management strategies. It is time to collaborate to gain consensus.

CLINICAL-EPIDEMIOLOGICAL RELATION BETWEEN SARS-COV-2 AND KAWASAKI DISEASE: AN INTEGRATIVE LITERATURE.

OBJECTIVE: To analyze the current scientific literature to document, in an integrative review, the main findings that correlate Kawasaki disease (KD) to COVID-19. DATA SOURCES: The search was carried out in June 2020 in the following databases: Biblioteca Virtual em Saúde (BVS), periódico da CAPES and U.S National Library of Medicine (PubMed). The combination of descriptors used was [(COVID-19 OR SARS-CoV-2) AND (Kawasaki disease)], and the inclusion criteria stipulated were studies published from January 2019 to June 2020, without restriction of language or location, and available online in full. News, editorials, comments, and letters, as well as duplicates and articles that did not answer the guiding question were excluded. DATA SYNTHESIS: A total of 97 articles were identified, of which seven comprised this review. The association of KD to the new coronavirus appears to trigger a severe clinical condition of vasculitis. Different from the usual, in this inflammatory syndrome, patients are older, and prevalence is higher in children from African or Caribbean ancestry; clinical and laboratory manifestations are also atypical, with a predominance of abdominal complaints and exaggerated elevation of inflammatory markers. In addition, there was a greater report of rare complications and greater resistance to the recommended treatment for KD. CONCLUSIONS: Pediatric COVID-19 and its potential association to severe KD, still unfamiliar to health professionals, reinforces the importance of testing patients with vasculitis for the new coronavirus and the need to wage high surveillance and preparation of the health system during the current pandemic.

Skin manifestations of COVID-19 in children: Part 2.

The current COVID-19 pandemic is caused by the SARS-CoV-2 coronavirus. The initial recognized symptoms were respiratory, sometimes culminating in severe respiratory distress requiring ventilation, and causing death in a percentage of those infected. As time has passed, other symptoms have been recognized. The initial reports of cutaneous manifestations were from Italian dermatologists, probably because Italy was the first European country to be heavily affected by the pandemic. The overall clinical presentation, course and outcome of SARS-CoV-2 infection in children differ from those in adults, as do the cutaneous manifestations of childhood. In this review, we summarize the current knowledge on the cutaneous manifestations of COVID-19 in children after thorough and critical review of articles published in the literature and from the personal experience of a large panel of paediatric dermatologists in Europe. In Part 1, we discussed one of the first and most widespread cutaneous manifestations of COVID-19, chilblain-like lesions. In this part of the review, we describe other manifestations, including erythema multiforme, urticaria and Kawasaki disease-like inflammatory multisystemic syndrome. In Part 3, we discuss the histological findings of COVID-19 manifestations, and the testing and management of infected children for both COVID-19 and any other pre-existing conditions.