The Epidemiology and Pathogenesis of Kawasaki Disease

Machine learning and artificial intelligence within pediatric autoimmune diseases: applications, challenges, future perspective

INTRODUCTION

Autoimmune disorders affect 4.5% to 9.4% of children, significantly reducing their quality of life. The diagnosis and prognosis of autoimmune diseases are uncertain because of the variety of onset and development. Machine learning can identify clinically relevant patterns from vast amounts of data. Hence, its introduction has been beneficial in the diagnosis and management of patients.

AREAS COVERED

This narrative review was conducted through searching various electronic databases, including PubMed, Scopus, and Web of Science This study thoroughly explores the current knowledge and identifies the remaining gaps in the applications of machine learning specifically in the context of pediatric autoimmune and related diseases.

EXPERT OPINION

Machine learning algorithms have the potential to completely change how pediatric autoimmune disorders are identified, treated, and managed. Machine learning can assist physicians in making more precise and fast judgments, identifying new biomarkers and therapeutic targets, and personalizing treatment strategies for each patient by utilizing massive datasets and powerful analytics.

Incidence and seasonality of Kawasaki disease in children in the Philippines, and its association with ambient air temperature

Background

Despite an unknown cause, Kawasaki disease (KD) is currently the primary leading cause of acquired heart disease in developed countries in children and has been increasing in recent years. Research efforts have explored environmental factors related to KD, but they are still unclear especially in the tropics. We aimed to describe the incidence of KD in children, assess its seasonality, and determine its association with ambient air temperature in the National Capital Region (NCR), Philippines from January 2009 to December 2019.

Methods

Monthly number of KD cases from the Philippine Pediatric Society (PPS) disease registry was collected to determine the incidence of KD. A generalized linear model (GLM) with quasi-Poisson regression was utilized to assess the seasonality of KD and determine its association with ambient air temperature after adjusting for the relevant confounders.

Results

The majority of KD cases (68.52%) occurred in children less than five years old, with incidence rates ranging from 14.98 to 23.20 cases per 100,000 population, and a male-to-female ratio of 1.43:1. Seasonal variation followed a unimodal shape with a rate ratio of 1.13 from the average, peaking in March and reaching the lowest in September. After adjusting for seasonality and long-term trend, every one-degree Celsius increase in the monthly mean temperature significantly increased the risk of developing KD by 8.28% (95% CI: 2.12%, 14.80%). Season-specific analysis revealed a positive association during the dry season (RR: 1.06, 95% CI: 1.01, 1.11), whereas no evidence of association was found during the wet season (RR: 1.10, 95% CI: 0.95, 1.27).

Conclusion

We have presented the incidence of KD in the Philippines which is relatively varied from its neighboring countries. The unimodal seasonality of KD and its linear association with temperature, independent of season and secular trend, especially during dry season, may provide insights into its etiology and may support enhanced KD detection efforts in the country.

Case Report: Identification of a CARD8 variant in all three patients with PFAPA syndrome complicated with Kawasaki disease

Background

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA syndrome), and Kawasaki disease (KD) are both considered to be disorders of the innate immune system, and the potential role of inflammasome activation in the immunopathogenesis of both diseases has been previously described.

Case presentation

Herein, we report the clinical courses of three patients who presented a rare combination of PFAPA syndrome and KD. Two patients who presented KD later developed the PFAPA syndrome, of whom one developed recurrent KD 2 years after the initial diagnosis. The third patient developed KD one year after the onset of PFAPA syndrome. The presence of both of these conditions within individual patients, combined with the knowledge that inflammasome activation is involved in both PFAPA syndrome and KD, suggests a shared background of inflammatory dysregulation. To elucidate the mechanism underlying shared inflammatory dysregulation, we investigated the roles of Nod-like receptors (NLRs) and their downstream inflammasome-related genes. All the patients had a frameshift variant in CARD8 (CARD8-FS). A previous study demonstrated a higher frequency of CARD8-FS, whose product loses CARD8 activity and activates the NLRP3 inflammasome, in patients with the PFAPA syndrome. Additionally, the NLRP3 inflammasome is known to be activated in patients with KD. Together, these results suggest that the CARD8-FS variant may also be essential in KD pathogenesis. As such, we analyzed the CARD8 variants among patients with KD. However, we found no difference in the variant frequency between patients with KD and the general Japanese population.

Conclusions

We report the clinical courses of three patients with a rare combination of PFAPA syndrome and KD. All the patients had the CARD8-FS variant. However, we could not find a difference in the variant frequency between patients with KD and the general Japanese population. As the frequency of KD is much higher than that of PFAPA among Japanese patients, and the cause of KD is multifactorial, it is possible that only a small portion of patients with KD harbor CARD8-FS as a causative gene.

Kawasaki disease and the environment: an enigmatic interplay

Kawasaki disease (KD) is a common systemic vasculitis of childhood. Although it has been almost 6 decades since Dr. Tomisaku Kawasaki reported the first case series of KD, the underlying cause remains a mystery. KD is a self-limiting disease. However, a dreaded complication is development of coronary artery abnormalities (CAAs). KD is the most common cause of acquired heart disease in children in the developed world and is being increasingly reported from developing countries too. Over the years, significant observations have been made about epidemiology of KD. It usually affects children below 5, has male preponderance and has significantly higher incidence in North East Asian countries. While several hypotheses have been proffered for etiology of KD, none have been conclusive. These include associations of KD epidemics in Japan and the United Stated with changes in tropospheric wind patterns suggesting wind-borne agents, global studies showing peaks of incidence related to season, and increased rates in populations with a higher socioeconomic profile related to hygiene hypothesis and vaccination. Furthermore, the self-limiting, febrile nature of KD suggests an infectious etiology, more so with sudden decline noted in cases in Japan with onset of COVID-19 mitigation measures. Finally, single nucleotide polymorphisms have been identified as possible risk alleles in patients with KD and their significance in the pathogenesis of this disease are also being defined. The purpose of this review is to elucidate the puzzling associations of KD with different environmental factors. Looking at patterns associated with KD may help us better predict and understand this disease.

Bioinformatics analysis and identification of hub genes of neutrophils in Kawasaki disease: a pivotal study

BACKGROUND

Kawasaki disease (KD) is considered the main contributor to acquired heart diseases in developed countries. However, the precise pathogenesis of KD remains unclear. Neutrophils play roles in KD. This study aimed to select hub genes in neutrophils in acute KD.

METHODS

mRNA microarray of neutrophils from four acute KD patients and three healthy controls was performed to screen differentially expressed mRNAs (DE-mRNAs). DE-mRNAs were analyzed and predicted by Gene Ontology (GO), Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathways, and protein-protein interaction networks. Real time-PCR was finally conducted to confirm the reliability and validity of the expression level of DE-mRNAs from blood samples of healthy controls and KD patients in both acute and convalescent stage.

RESULTS

A total of 1950 DE-mRNAs including 1287 upregulated and 663 downregulated mRNAs were identified. GO and KEGG analyses revealed the DE-mRNAs were mainly enriched in the regulation of transcription from RNA polymerase II promoter, apoptotic process, intracellular signal transduction, protein phosphorylation, protein transport, metabolic pathways, carbon metabolism, lysosome, apoptosis, pyrimidine metabolism, alzheimer disease, prion disease, sphingolipid metabolism, huntington disease, glucagon signaling pathway, non-alcoholic fatty liver disease, pyruvate metabolism, sphingolipid signaling pathway, and peroxisome. Twenty hub DE-mRNAs were selected including GAPDH, GNB2L1, PTPRC, GART, HIST2H2AC, ACTG1, H2AFX, CREB1, ATP5A1, ENO1, RAC2, PKM, BCL2L1, ATP5B, MRPL13, SDHA, TLR4, RUVBL2, TXNRD1, and ITGAM. The real-time PCR results showed that BCL2L1 and ITGAM mRNA were upregulated in acute KD and were normalized in the convalescent stage.

CONCLUSIONS

These findings may improve our understanding of neutrophils in KD. Key Points • Neutrophilic BCL2L1 and ITGAM mRNA were first reported to be correlated with the pathogenic mechanism of KD.

LncRNAs in Kawasaki disease and Henoch-Schönlein purpura: mechanisms and clinical applications

Kawasaki disease (KD) and Henoch-Schönlein purpura (HSP) are the two most predominant types of childhood vasculitis. In childhood vasculitis, factors such as lack of sensitive diagnostic indicators and adverse effects of drug therapy may cause multiorgan system involvement and complications and even death. Many studies suggest that long noncoding RNAs (lncRNAs) are involved in the mechanism of vasculitis development in children and can be used to diagnose or predict prognosis by lncRNAs. In existing drug therapies, lncRNAs are also involved in drug-mediated treatment mechanisms and are expected to improve drug toxicity. The aim of this review is to summarize the link between lncRNAs and the pathogenesis of KD and HSP. In addition, we review the potential applications of lncRNAs in multiple dimensions, such as diagnosis, treatment, and prognosis prediction. This review highlights that targeting lncRNAs may be a novel therapeutic strategy to improve and treat KD and HSP.

Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: A Spectrum of Postinfectious Hyperinflammatory Disease

Kawasaki disease and multisystem inflammatory syndrome in children are hyperinflammatory conditions that share similar emerging pathophysiology hypotheses, clinical features, treatment strategies, and outcomes. Although both conditions have key differences, growing evidence suggests that both conditions might be closely related on a larger spectrum of postinfectious autoimmune responses.

Relationship between IL-17A gene polymorphism and susceptibility to Kawasaki disease

OBJECTIVES

Kawasaki disease (KD) is the most common autoimmune vasculitis syndrome in children, which supposed be a complex polygenic disorder. Interleukin-17 (IL-17) is a member of the pro-inflammatory cytokine family, which has a strong pro-inflammatory effect and can participate in various acute and chronic inflammatory responses. This study aims to investigate the relationship between the single-nucleotide polymorphism (SNP) locus rs3819025 in the IL-17A gene and the susceptibility to KD.

METHODS

A total of 120 patients with KD who met the diagnostic criteria (the KD group) and 120 healthy children (the control group) were enrolled retrospectively in this study. Polymerase chain reaction (PCR) and DNA direct sequencing were used to detect the SNPs of children in the 2 groups.

RESULTS

The frequencies of GG, GA, and AA genotypes of rs3819025 locus in the IL-17A gene in the KD group were 82.5%, 17.5%, and 0, respectively, and the frequencies of GG, GA, and AA genotypes in the control group were 72.5%, 22.5%, and 5.0%, respectively. There were significant differences in both genotype (χ2=7.524, P=0.023). The allele frequencies G and A of rs3819025 locus in the KD group were 91.25% and 8.75%, respectively, while those in the control group were 83.75% and 16.25%, respectively. There was significant difference between the 2 groups (χ2=6.171, P=0.013). The distribution frequencies of GG or GA genotype and G or A allele were 88.46% or 11.54% and 94.23% or 5.77% in the KD group with coronary artery lesion, respectively. The distribution frequencies of GG or GA genotype and G or A allele were 78.72% or 21.28% and 89.36% or 10.64% in the KD group without coronary artery lesion, respectively. There were no significant differences in genotype and allele frequencies of rs3819025 between the KD with coronary artery lesion group and the KD group without coronary artery lesion (both P>0.05). Besides, children with the allele A had a 2.023 times higher risk of KD than those without the allele A (χ2=6.171, P=0.013; OR=2.023, 95% CI 1.151 to 3.557).

CONCLUSIONS

The locus rs3819025 in the IL-17A gene is associated with the pathogenesis of KD. The allele A of the locus rs3819025 in the IL-17A gene may be a risk factor for KD.

Kawasaki disease in children: a retrospective cross-sectional study

Introduction

Kawasaki disease (KD) is a systemic vasculitis, seen mostly in children. Epidemiology of KD is dependent on geographical location and seasonality. Although many years have passed since the first report of KD, multiple related factors are still unknown.

Material and methods

We investigated the clinical, paraclinical, and therapeutic aspects of KD in Kerman, Iran by performing a retrospective, descriptive, cross-sectional study on all children hospitalized due to KD between 2007 and 2020.

Results

A total of 340 patients with mean ±SD age of 29.83 ±22.55 months participated in the study. Most of our patients were two to five years old. The male : female ratio was ~ 1.4 : 1. A few of our patients had a family history of KD or vasculitis (0.3%, 1.7%). Typical KD was more common by a large margin (316 patients with typical KD). More than half of our patients had a duration of hospitalization of under ten days. All of our patients were febrile. Hand/foot and lip/mouth changes were the second and third most common clinical findings in more than 60% of our patients. Other manifestations were conjunctivitis in 40%, skin rashes in 34.8%, gastrointestinal manifestations in 33.9%, and lymphadenopathy in 25.3%. Echocardiography revealed abnormalities in 78.6% of the participants; coronary artery aneurysm (CAA) was the most frequent (22.5%) and follow-up echocardiography revealed that all of them regressed within 6 months after treatment. The two laboratory tests with the highest ratio of abnormality were erythrocyte sedimentation rate (95%) and hemoglobin (83.3%). C-reactive protein and liver function tests were also abnormal in most patients. All of our patients received intravenous immunoglobulin and acetylsalicylic acid.

Conclusions

Kawasaki disease must be considered in every febrile child, especially those with risk factors, because timely diagnosis and treatment are essential to prevent complications. Health policies should focus on appropriate diagnosis and treatment to prevent the occurrence of sequelae.

A LncRNA gene polymorphism (rs1814343) is associated with the risk of coronary artery lesions in southern Chinese Kawasaki disease patients

BACKGROUND

Kawasaki disease (KD) is a multisystemic angiitis, and its most disastrous complication is coronary artery lesions (CALs). Recently, the role of long non-coding RNAs (lncRNAs) in KD has been reported. rs1814343 is a lncRNA, but the relationship between the lncRNA rs1814343 polymorphism and KD risk remains elusive.

METHODS

We enrolled 1625 Kawasaki disease patients (583 patients with CAL and 1042 without CAL) and 1000 healthy controls from a southern Chinese population. We genotyped the rs1814343 C > T polymorphism in KD and control patients using the TaqMan method. The odds ratio (OR) and 95% confidence interval (CI) were used to estimate the strength of the association.

RESULTS

There was no significant association between the lncRNA rs1814343 C > T polymorphism and KD susceptibility. However, we stratified patients in this study by CAL and sex. First, compared with the control groups, we found that the rs1814343 genotype increased risk for KD patients with CAL (TT vs. CC + CT: OR = 1.36, 95% CI = 1.08-1.71, p = 0.009). Moreover, when KD patients were stratified by CAL, the TT genotypes of this lncRNA polymorphism contributed to a relatively higher occurrence of KD with CAL than that was found in the CC/CT genotype patients (TT vs. CC + CT: OR = 1.35, 95% CI = 1.07-1.69, p = 0.011). In addition, our research suggested that the TT variant genotype in the lncRNA rs1814343 had an obvious risk of KD with CAL susceptibility in male children.

CONCLUSION

The lncRNA rs1814343 C > T polymorphism was related to higher susceptibility of KD with CAL.

Unexpectedly high incidence of Kawasaki Disease in a Canadian Atlantic Province- an 11-year retrospective descriptive study

BACKGROUND

Kawasaki Disease (KD) is the leading cause of acquired heart disease in children in developed countries with a variable incidence worldwide. Previous studies reported an unexpectedly high incidence of KD in the Canadian Atlantic Provinces. The goals of our study were to validate this finding in the province of Nova Scotia and to carefully review patients' characteristics and disease outcomes.

METHODS

This was a retrospective review of all children < 16 years old from Nova Scotia diagnosed with KD between 2007-2018. Cases were identified using a combination of administrative and clinical databases. Clinical information was collected retrospectively by health record review using a standardized form.

RESULTS

Between 2007-2018, 220 patients were diagnosed with KD; 61.4% and 23.2% met the criteria for complete and incomplete disease, respectively. The annual incidence was 29.6 per 100,000 children < 5 years. The male to female ratio was 1.3:1 and the median age was 3.6 years. All patients diagnosed with KD in the acute phase received intravenous immunoglobulin (IVIG); 23 (12%) were refractory to the first dose. Coronary artery aneurysms were found in 13 (6%) patients and one patient died with multiple giant aneurysms.

CONCLUSION

We have confirmed an incidence of KD in our population which is higher than that reported in Europe and other regions of North America despite our small Asian population. The comprehensive method to capture patients may have contributed to the detection of the higher incidence. The role of local environmental and genetic factors also deserves further study. Increased attention to regional differences in the epidemiology of KD may improve our understanding of this important childhood vasculitis.

Research trends on causes of Kawasaki disease in the COVID-19 era: focus on viral infections

Despite studies on the etiology of Kawasaki disease (KD) ongoing for half a century since its discovery, its cause has not yet been clearly identified. Although the clinical, epidemiological, and pathophysiological characteristics of KD are presumed to be closely related to infectious diseases, studies of various pathogens to identify its etiology have been actively conducted. To date, bacteria, fungi, and viruses have been investigated to determine the relationship between KD and infection, among which viruses have attracted the most attention. In particular, during the coronavirus disease 2019 pandemic, there were many reports in Europe of a sharp increase in cases of Kawasaki-like disease (KLD), while conflicting reports that the prevalence of KD decreased due to thorough "social distancing" or "wearing mask" in Asian countries drew more attention regarding the association between KD and viral infection. Therefore, the differential diagnosis of KD from KLD with these similar spectra has become a very important issue; simultaneously, research to solve questions about the association between KD and viral infections, including sudden acute respiratory syndrome coronavirus 2, is drawing attention again. Moreover, a new concept has emerged that immune responses occurring in patients with KD can be caused by the pathogen itself as well as host cells damaged by infection. This paper summarizes the research trends into KD etiology and related pathophysiology, especially its association with viral infections, and present future research tasks to increase our understanding of KD.

Clinical characteristics and short-term outcomes of multisystem inflammatory syndrome in a country with a high prevalence of KD

BACKGROUND

The COVID-19 pandemic has spread continuously. Multisystem inflammatory syndrome in children (MIS-C), like Kawasaki disease (KD), is a potentially severe illness in children that appears to be a delayed, post-infectious complication of COVID-19. However, based on the relatively low MIS-C prevalence and high KD prevalence in Asian children, the clinical features of MIS-C are not fully recognized, especially after the spread of the Omicron variant. Here, we aimed to identify the clinical characteristics of MIS-C in a country with high KD prevalence.

METHODS

We retrospectively analyzed 98 children diagnosed with KD and MIS-C admitted to Jeonbuk National University Hospital between January 1, 2021, and October 15, 2022. Twenty-two patients were diagnosed with MIS-C, following CDC diagnostic criteria for MIS-C. We reviewed medical records for clinical features, laboratory findings, and echocardiography.

RESULTS

Age, height, and weight were higher for patients with MIS-C than for those with KD. Lymphocytes percentage was lower, and the segmented neutrophil percentage was higher in the MIS-C group. The inflammation marker C-reactive protein was higher in the MIS-C group. Prothrombin time was prolonged in the MIS-C group. Albumin level was lower in the MIS-C group. The MIS-C group had lower potassium, phosphorus, chloride, and total calcium. Twenty-five percent of patients diagnosed with MIS-C had positive RT-PCR, and all the patients were N-type SARS-CoV-2 antibody-positive. Albumin ≤3.85 g/dl effectively predicted MIS-C. Regarding echocardiography, the right coronary artery z-score, the absolute value of apical 4-chamber left ventricle longitudinal strain, and the ejection fraction (EF) was significantly lower in the MIS-C group. A month after diagnosis using echocardiographic data, all coronary artery z-scores had reduced significantly. EF and fractional shortening (FS) also improved one month after diagnosis.

CONCLUSION

Albumin values can differentiate MIS-C and KD. In addition, a decrease in the absolute LV longitudinal strain value, EF, and FS was observed in the MIS-C group using echocardiography. Coronary artery dilatation was not evident at the initial diagnosis; however, a change in coronary artery size, EF, and FS was observed on follow-up echocardiography a month after diagnosis.

Evaluation of the association of birth order and group childcare attendance with Kawasaki disease using data from a nationwide longitudinal survey

Background

Kawasaki disease (KD) is a form of pediatric systemic vasculitis. Although the etiology remains unclear, infections have been identified as possible triggers. Children with a later birth order and those who attend childcare are at a higher risk of infections due to exposure to pathogens from their older siblings and other childcare attendees. However, longitudinal studies exploring these associations are limited. Thus, we aimed to elucidate the relationship between birth order, group childcare attendance, and KD, using a nationwide longitudinal survey in Japan.

Methods

In total, 36,885 children born in Japan in 2010 were included. The survey used questionnaires to identify hospitalized cases of KD. We evaluated the relationship between birth order classification, group childcare attendance, and KD prevalence every year, from 6 to 66 months of age. For each outcome, odds ratios (ORs), and 95% confidence intervals (CIs) were estimated after adjusting for child factors, parental factors, and region of residence.

Results

Children with higher birth orders were more likely to be hospitalized with KD at 6-18 months of age (second child OR: 1.77, 95% CI: 1.25-2.51; third child OR: 1.70, 95% CI: 1.08-2.65). This trend was stronger for children who did not attend group childcare (second child OR: 2.51, 95% CI: 1.57-4.01; third child OR: 2.41, 95% CI: 1.30-4.43). An increased risk of KD hospitalization owing to the birth order was not observed in any age group for children in the childcare group.

Conclusions

Children with higher birth orders were at high risk for hospitalization due to KD at 6-18 months of age. The effect of birth order was more prominent among the children who did not attend group childcare.

SARS-CoV-2 infection in the context of Kawasaki disease and multisystem inflammatory syndrome in children

Recent studies have noted an increasing number of Kawasaki-like cases in the pediatric population following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In the literature, the condition is described as multiple inflammatory syndrome in children (MIS-C) or pediatric inflammatory syndrome (PIMS). A similar clinical course of Kawasaki disease (KD) and MIS-C causes difficulties in distinguishing between both conditions. However, the differential diagnosis is crucial since patients with MIS-C can present severe symptoms (myocardial dysfunction, fever, mucocutaneous symptoms) and require more extensive monitoring during treatment than children diagnosed with KD. Along with assessing epidemiological and genetic factors, it is imperative to estimate the risk of developing MIS-C in KD patients with confirmed SARS-CoV-2 infection. Genetic predispositions, such as the ITPKC gene polymorphism in KD, ACE deletion (D) polymorphism in SARS-CoV-2, and inborn errors of immunity (IEIs) in MIS-C affect the regulation of immune system complex clearances and cellular adaptations. The virus has a tropism for both vascular and respiratory cells, which further causes additional symptoms necessitating standard therapy with antithrombotic treatment. The diagnostic criteria for KD, MIS-C, and SARS-CoV-2 help differentiate each condition and optimize treatment strategies. Unfortunately, long-term outcomes in KD patients who develop MIS-C due to SARS-CoV-2 infection have been inadequately documented due to the timing of the pandemic, further displaying the need for longitudinal studies in these patients. This review underlines the differences in diagnosis and treatment of KD and MIS-C. Overall, children with KD may develop MIS-C in the setting of SARS-CoV-2 infection, but further research is needed to outline specific etiologies, prognostic factors, and diagnoses.

Clinical features of Kawasaki disease initially mimicking retropharyngeal abscess: a retrospective analysis

OBJECTIVE

Incomplete Kawasaki disease (IKD) initially presenting as retropharyngeal abnormality is very rare and is prone to misdiagnosis and missed diagnosis, often leading to poor prognosis. Most patients were misdiagnosed with retropharyngeal abscesses. Here, we describe and compare IKD patients initially presenting with retropharyngeal abnormalities, typical KD patients without retropharyngeal abnormalities and retropharyngeal abscess patients.

METHODS

We performed a retrospective case-control study comparing IKD patients initially presenting with retropharyngeal abnormalities to both KD patients without retropharyngeal abnormalities and retropharyngeal abscess patients admitted to Shenzhen Children's Hospital between January 2016 and December 2021.

RESULTS

We evaluated data from 10 IKD patients initially presenting with retropharyngeal abnormalities (Group A), 20 typical KD patients (Group B) and 16 surgical drainage confirmed retropharyngeal abscess patients (Group C). Compared to Group B, we observed that Group A was older and had a more intense inflammatory response. On the day of admission, Groups A and C had similar early clinical presentations, and there were no significant differences in any major signs or symptoms. Close observation for the development of new KD signs and symptoms and unresponsiveness to empirical antibiotic therapy after 3 days is extremely important. The CRP (p = 0.011), AST (p = 0.002) and ALT (p = 0.013) levels were significantly higher and the WBC (P = 0.040) levels were significantly lower in Group A than in Group C. Neck radiological findings, such as the presence of ring enhancement (p = 0.001) and mass effects on the airway, are also useful tools for distinguishing these two diseases.

CONCLUSION

The careful observation of the signs and symptoms of this disease and the comprehensive analysis of the laboratory tests and neck radiological findings may help clinicians become aware of retropharyngeal abnormality as an atypical presentation of KD. Then, unnecessary treatments could be reduced, and the occurrence of serious complications can be avoided.

Incidence of Kawasaki Disease Before and After the COVID-19 Pandemic in Japan: Results of the 26th Nationwide Survey, 2019 to 2020

IMPORTANCE

Global studies have reported that the incidence of Kawasaki disease (KD) declined during the COVID-19 pandemic. These studies suggest that the global pandemic and its accompanying mitigation measures may provide an important opportunity to explore the hypothesis of a KD pathogenesis.

OBJECTIVE

To compare changes in KD incidence in Japan before and after the start of the COVID-19 pandemic.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted using the data set from Japan's 26th nationwide KD survey that obtained information on patients who were diagnosed with KD in Japan from January 1, 2019, through December 31, 2020.

MAIN OUTCOMES AND MEASURES

Kawasaki disease incidence rates were calculated by referring to the national population data in the vital statistics data for Japan.

RESULTS

A total of 28 520 patients were identified (16 236 male individuals [56.9%]; median [IQR] age, 26 [14-44] months). A total of 17 347 patients were diagnosed with KD in 2019 and 11 173 were diagnosed in 2020, representing a 35.6% reduction in the number of patients diagnosed in 2020 compared with the previous year. Patient distributions for days of illness at the first hospital visit were almost identical in 2019 and 2020, suggesting that the decrease in KD incidence likely was not associated with pandemic-related delays in seeking treatment. The proportion of patients diagnosed with KD who were younger than 12 months was significantly larger in 2020 than in 2019 (21.6% vs 19.4%; P < .001). Compared with KD incidence among younger patients, the incidence among those 24 months and older declined rapidly after initiation of COVID-19 special mitigation measures, with a greater percentage reduction (58.3% reduction in July), but rebounded faster after the end of the special mitigation period. By contrast, the incidence among patients younger than 12 months declined moderately after the initiation of the special mitigation period, with a lower percentage reduction (40.3% reduction in October), and rebounded at a later phase.

CONCLUSIONS AND RELEVANCE

In this cohort study, the number of patients diagnosed with KD decreased by approximately one-third across Japan in 2020, with no indication that parents avoided a hospital visit. Differences in KD incidence reduction patterns before and after the initiation of COVID-19 pandemic mitigation measures were found in patients with KD aged younger than 12 months compared with those 24 months or older, suggesting a potential KD pathogenesis involving transmission among children.

Coronavirus disease 2019-related Kawasaki syndrome: a case report

BACKGROUND

Coronavirus disease 2019 has changed the pattern of some diseases in the world, especially in pediatrics. Despite data suggesting that the pediatric population is less affected by coronavirus disease-19 infection, new concerns have been raised owing to reported cases with hyperinflammatory conditions such as Kawasaki disease.

CASE PRESENTATION

We report herein the case of a pediatric patient diagnosed and treated for classic Kawasaki disease in the setting of confirmed coronavirus disease 2019 infection. She was an 8-year-old, previously healthy, and fully immunized Iranian girl who initially presented to the pediatric emergency department with 5 days of intermittent fever, followed by abdominal pain, nausea, and vomiting. She was admitted for fever and abdominal pain to the surgery service of Akbar Hospital with suspected appendicitis.

CONCLUSIONS

This case report may serve as a useful reference to other clinicians caring for pediatric patients affected by coronavirus disease 2019 infection. Standard therapeutic interventions for Kawasaki disease must be performed to prevent critical coronary aneurysm-related complications in the coronavirus disease 2019 era.

Regional Differences in Kawasaki Disease Incidence Reduction Before and After the Onset of the Coronavirus Disease 2019 Pandemic

OBJECTIVE

To assess regional differences in reduction of the incidence of Kawasaki disease during the mitigation period for the coronavirus disease 2019 pandemic, with a hypothesis that more sparsely populated regions have fewer opportunities for human-to-human contact, resulting in a greater reduction in the incidence of Kawasaki disease.

STUDY DESIGN

A retrospective ecological study was conducted using data from patients hospitalized for Kawasaki disease as well as infectious diseases surveillance reports in Shiga Prefecture, Japan, during 2015-2020. We defined the periods before and after the onset of pandemic as January 2015-March 2020 and as April 2020-December 2020, respectively. We compared the reductions in the incidence of Kawasaki disease among 6 administrative regions in the prefecture according to the density of the populations.

RESULTS

A total of 1290 patients with Kawasaki disease were identified. The incidence of Kawasaki disease (per 100 000 person-years) was significantly reduced after the coronavirus disease 2019 pandemic onset (period before pandemic onset, 105.6 [95% CI 99.8-111.8]; period after pandemic onset, 68.6 [95% CI 56.7-83.0]). During the period after pandemic onset, the incidence of Kawasaki disease was significantly reduced in May, compared with the corresponding period in previous years. The number of patients aged 2-4 years was significantly reduced after the pandemic onset. Notably, greater reductions in the incidence of Kawasaki disease were found in regions with lower population densities.

CONCLUSIONS

Assuming that there were fewer opportunities for human-to-human contact in more sparsely populated regions during the pandemic mitigation period, our findings support the hypothesis that human-to-human contact may be associated with development of Kawasaki disease.

Association of ITPKC gene polymorphisms rs28493229 and rs2290692 in North Indian children with Kawasaki disease

BACKGROUND

Single-nucleotide polymorphisms (SNPs) of several genes are linked to the etiopathogenesis of Kawasaki disease (KD). Association of SNPs of inositol 1,4,5-triphosphate-3-kinase C (ITPKC) gene with susceptibility to KD and coronary artery lesions (CALs) has been observed in children of certain ethnicities, but not from others. The present study was planned to explore this genetic association in the North Indian cohort.

METHODS

Fifty children with KD and 50 age- and sex-matched controls were studied for two SNPs (rs28493229 and rs2290692) of the ITPKC gene using polymerase chain reaction and restriction fragment length polymorphism. Findings were confirmed by Sanger sequencing. A meta-analysis was also carried out for GG and CC genotypes of the SNPs.

RESULTS

There was significant association between KD susceptibility and CG + GG genotype of rs2290692 (p = 0.015, odds ratio = 4.1, 95% confidence interval = 1.38-13.83). None of the single alleles or genotypes of the SNPs of ITPKC were, however, significantly associated with KD susceptibility. A meta-analysis also did not show any significant association of these SNPs to KD susceptibility.

CONCLUSIONS

Our findings suggest that ITPKC gene SNPs (rs28493229 and rs2290692) did not have a significant association with susceptibility to KD in children from North India. Larger multicentric studies incorporating different ethnicities are required to understand the genetic basis of KD.

IMPACT

While SNP rs28493229 of the ITPKC gene is not found to be associated with susceptibility to KD, the combined genotype of SNP rs2290692 is shown to be associated. Impact of ITPKC gene SNP on KD is different across different races and ethnicities. We could find an association of the combined genotype of rs2290692 with it in the Indian population. This study highlights that phenotype and genotypic association of KD varies with ethnicities. Larger multicentric studies are required to reach a conclusion regarding the genetic association of KD.

Immunophenotyping of peripheral blood cells allows to discriminate MIS-C and Kawasaki disease

BACKGROUND

The pathogenesis of the novel described multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) is still debated as it is not clear if they are the same or different nosological entities. However, for both the diseases a rapid and unequivocal diagnosis is mandatory to start the therapy before the onset of severe complications. In this study, we aimed to evaluate the white cell populations in MIS-C and KD as potential markers to discriminate between the two diseases.

METHODS

We studied white cell populations by flow cytometry in 46 MIS-C and 28 KD patients in comparison to 70 age-matched healthy children.

RESULTS

MIS-C patients had a significant lymphopenia that involved both B and T populations while KD patients showed a significant neutrophilia and thrombocythemia. Granulocyte/lymphocyte ratio helped to diagnose both MIS-C and KD with a high diagnostic sensitivity, while a multivariate analysis of granulocyte and T lymphocyte number contributed to discriminate between the two diseases.

CONCLUSIONS

The relevant lymphopenia observed in MIS-C patients suggests that the disease would be a post-infectious sequel of COVID-19 immunologically amplified by a massive cytokine release, while the significant neutrophilia and thrombocythemia observed in KD confirmed that the disorder has the genesis of a systemic vasculitis. The analysis of a panel of circulating cells may help to early diagnose and to discriminate between the two diseases.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s41231-022-00128-2.

The Associated of the Risk of IVIG Resistance in Kawasaki Disease with ZNF112 Gene and ZNF180 Gene in a Southern Chinese Population

Background

Kawasaki disease (KD) was one of the most common primary vasculitis. IVIG resistance was associated with an increased risk of coronary artery aneurysm. Accumulating evidences demonstrated that inflammatory gene polymorphisms might play important roles in IVIG resistance, and zinc finger proteins were closely related to immune inflammation regulation, but the effect of ZNF112/rs8113807 and ZNF180/rs2571051 on IVIG resistance in KD patients has not been reported.

Methods

A total of 996 KD patients were recruited, and the assay of TaqMan-real-time polymerase chain reaction was used for ZNF112/rs8113807 and ZNF180/rs2571051 genotyping. Odds ratio (OR) and 95% confidence interval (CI) were calculated for estimating the relationship between the polymorphisms of the both SNPs (ZNF112/rs8113807 and ZNF180/rs2571051) and the risk of IVIG resistance.

Results

Both of the ZNF112/rs8113807 CC/TC genotype and the ZNF180/rs2571051 TT/CT genotype increased the risk of IVIG resistance in KD (rs8113807: CC vs TT: adjusted OR = 1.83, 95% CI = 1.06–3.16, p = 0.0293; CC/TC vs TT adjusted: OR = 1.49, 95% CI = 1.10–2.02, p = 0.0094. rs2571051: TT vs CC adjusted: OR = 2.64, 95% CI = 1.62–4.29, p < 0.0001; TT/CT vs CC adjusted: OR = 2.14, 95% CI = 1.37–3.37, p = 0.0009; TT vs CC/CT adjusted: OR = 1.66, 95% CI = 1.22–2.27, p = 0.0014). Furthermore, the combinative analysis of risk genotypes in ZNF112/rs8113807 and ZNF180/rs2571051 showed that patients with two unfavorable genotypes were more likely to increase risk of IVIG resistance than those who carried with zero or one unfavorable genotypes (adjusted: OR = 1.68, 95% CI = 1.24–2.27, p = 0.0008).

Conclusion

Our findings enriched the genetic background of IVIG resistance risk in the KD development and suggested that the ZNF112/rs8113807 C-carrier and the ZNF180/rs2571051 T-carrier were associated with increased risk of IVIG resistance in KD patients in Chinese southern population.

Association of single nucleotide polymorphism rs113420705 of CASP3 in children with Kawasaki disease from North India

Background

Kawasaki disease is a pediatric, systemic, vasculitic disorder. Its exact etiology is still unknown. Genetic polymorphisms are being investigated as susceptibility factor for this disorder. These are likely to vary among different populations.

Aim

To investigate the association of single nucleotide polymorphism (SNP) rs113420705 of CASP3 in Kawasaki disease (KD) from North India.

Settings and Design

Observational, case-control study.

Methods

Polymerase chain reaction and bidirectional Sanger sequencing was used for determining genotypes of SNP rs113420705 in 45 cases of KD and 50 healthy age- and sex-matched controls. Allele and genotype frequencies were assessed and compared between the groups.

Results

Among 45 cases, 32 had TT (71.1%), 13 had CT (28.9%) and none had CC genotype of SNP rs113420705. No significant differences in allele, genotype, or carrier frequencies of rs113420705 were found between the two groups. A comparison was also made between subgroups of KD with coronary abnormality (7 children; 15.5%) and KD with normal coronaries (38 children; 84.4%). The C allele was significantly overexpressed in KD with coronary abnormality group (P = 0.005). However, no difference was noted in the genotype frequencies.

Conclusion

CT genotype of rs113420705 of CASP3 showed a trend to significance with the occurrence of KD in children in North India. However, we could not establish any association between minor allele C and susceptibility to KD. C allele appeared to be over expressed in children with KD with coronary abnormalities. Larger studies will help us to reach conclusive evidence applicable to all ethnicities.

The position of geochemical variables as causal co-factors of diseases of unknown aetiology

Abstract

The term diseases of unknown aetiology (DUA) or idiopathic diseases is used to describe diseases that are of uncertain or unknown cause or origin. Among plausible geoenvironmental co-factors in causation of DUA, this article focusses on the entry of trace elements, including metals and metalloids into humans, and their involvement in humoral and cellular immune responses, representing potentially toxic agents with implications as co-factors for certain DUA. Several trace elements/metals/metalloids (micronutrients) play vital roles as co-factors for essential enzymes and antioxidant molecules, thus, conferring protection against disease. However, inborn errors of trace element/metal/metalloid metabolisms can occur to produce toxicity, such as when there are basic defects in the element transport mechanism. Ultimately, it is the amount of trace element, metal or metalloid that is taken up, its mode of accumulation in human tissues, and related geomedical attributes such as the chemical form and bioavailability that decisively determine whether the exerted effects are toxic or beneficial. Several case descriptions of DUA that are common worldwide are given to illustrate our knowledge so far of how trace element/metal/metalloid interactions in the immune system may engender its dysregulation and be implicated as causal co-factors of DUA.

Article highlights

The importance of a proper understanding of geochemical perturbations in human metabolisms is emphasisedIt is proferred that such an understanding would aid greatly in the decipherment of diseases of unknown aetiology (DUA)The thesis presented may pave the way towards better diagnosis and therapy of DUA.

Bacille Calmette-Guérin Site Reactivation of Kawasaki Disease in Infants under 3 Months of Age: Relation with Diagnosis and Prognosis

Diagnosis of Kawasaki disease in infants under 3 months of age is challenging. This study aimed to confirm the diagnostic efficacy of BCGitis in patients with Kawasaki disease aged <3 months. Overall, 473 children were enrolled; they were grouped by age into group 1 (≤3 months, n = 19) and group 2 (>3 months, n = 454). Data, including clinical features and laboratory results, were analyzed and compared between the groups. In group 1, 89% of patients showed Bacille Calmette-Guérin site reactivation. In group 1, total duration of fever and fever duration before initial treatment were significantly shorter than in group 2 (p = 0.001). The incidences of conjunctival injection, changes in extremities (erythema and edema), and cervical lymphadenopathy were significantly lower (p = 0.006, p = 0.040, and p < 0.001, respectively), and desquamation was higher in group 1 (p = 0.004). The incidences of incomplete Kawasaki disease, coronary artery complications, and resistance to intravenous immunoglobulin did not differ between the groups. Kawasaki disease should be suspected in infants aged <3 months with unexplained fever and BCGitis, even if the principal clinical symptoms are not fully presented. BCGitis in infantile Kawasaki disease is a useful sign and can help in the diagnosis of Kawasaki disease.

Two Distinct Illnesses Consistent With MIS-C in a Pediatric Patient

Multisystem inflammatory syndrome in children (MIS-C) is a severe inflammatory response described in children after infection with severe acute respiratory syndrome coronavirus 2. We present a case of a 9-year-old African American boy with 2 distinct illnesses that were both consistent with MIS-C. He first presented in the early stages of our understanding of MIS-C with predominantly neurologic and gastrointestinal symptoms and demonstrated elevated inflammatory markers consistent with MIS-C. He was treated with intravenous immunoglobulin with complete resolution of signs and symptoms. After 7 months of good health, he returned with a second, distinct illness characterized by fever, rash, gastrointestinal symptoms, and elevated inflammatory markers that met the criteria for MIS-C. In addition, we identified new dilatation of the left anterior descending coronary artery. He improved rapidly after treatment with intravenous immunoglobulin, aspirin, and steroids. Our report highlights the need to achieve a better understanding of this entity's pathogenesis and clinical course and to improve anticipatory guidance for children with MIS-C.

Cardiovascular Manifestations in Multisystem Inflammatory Syndrome in Children (MIS-C) Associated with COVID-19 According to Age

Cardiac involvement in multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus-19 disease is often observed with a high risk of heart failure. The aim is to describe cardiovascular involvement, management and early outcome in MIS-C by comparing cardiovascular manifestations in children younger and older than 6 years old. This retrospective observational study included 25 children with MIS-C, admitted to a single pediatric center between March 2020 and September 2021. The median age was 5 years (13 patients under 6 years and 12 over 6 years); coronary artery abnormalities were observed in 77% of preschoolers, with small and medium aneurysms in half of the cases and two cases of mild ventricular dysfunction. School-age children presented myopericardial involvement with mild to moderate ventricular dysfunction in 67% of cases, and two cases of transient coronary dilatation. There was a significant NT-pro-BNP and inflammatory markers increase in 25 of the patients, and mild elevation of troponin I in 9. All patients were treated with intravenous immunoglobulin and corticosteroids, and 8 with anakinra. None of the patients needed inotropes or intensive care unit admission. Our study shows the frequent cardiovascular involvement in MIS-C with a peculiar distribution, according to different age group: coronary artery anomalies were more frequent in the younger group, and myopericardial disease in the older one. A prompt multitarget, anti-inflammatory therapy could probably contribute to a favorable outcome.

A Review of Coronaviruses Associated With Kawasaki Disease: Possible Implications for Pathogenesis of the Multisystem Inflammatory Syndrome Associated With COVID-19

Multisystem Inflammatory Syndrome in Children (MIS-C), representing a new entity in the spectrum of manifestations of COVID-19, bears symptomatic resemblance with Kawasaki Disease (KD). This review explores the possible associations between KD and the human coronaviruses and discusses the pathophysiological similarities between KD and MIS-C and proposes implications for the pathogenesis of MIS-C in COVID-19. Since 2005, when a case-control study demonstrated the association of a strain of human coronavirus with KD, several studies have provided evidence regarding the association of different strains of the human coronaviruses with KD. Thus, the emergence of the KD-like disease MIS-C in COVID-19 may not be an unprecedented phenomenon. KD and MIS-C share a range of similarities in pathophysiology and possibly even genetics. Both share features of a cytokine storm, leading to a systemic inflammatory response and oxidative stress that may cause vasculitis and precipitate multi-organ failure. Moreover, antibody-dependent enhancement, a phenomenon demonstrated in previous coronaviruses, and the possible superantigenic behavior of SARS-CoV-2, possibly may also contribute toward the pathogenesis of MIS-C. Lastly, there is some evidence of complement-mediated microvascular injury in COVID-19, as well as of endotheliitis. Genetics may also represent a possible link between MIS-C and KD, with variations in FcγRII and IL-6 genes potentially increasing susceptibility to both conditions. Early detection and treatment are essential for the management of MIS-C in COVID-19. By highlighting the potential pathophysiological mechanisms that contribute to MIS-C, our review holds important implications for diagnostics, management, and further research of this rare manifestation of COVID-19.

Predictive Role of IL-2R and IL-10 in the Anti-inflammatory Response and Antiplatelet Therapy of Kawasaki Disease: A Retrospective Study

To date, Kawasaki disease (KD) has only been able to be diagnosed and evaluated using clinical characteristics. Additionally, the therapeutic effect and cardiovascular complications could not be verified until its occurrence. The present retrospective study analyzed the dynamic alterations of inflammatory cytokines, platelet (PLT) count, and subgroups of lymphocytes, such as cluster of differentiation (CD) 8+ T cells and CD19+ B cells, under different conditions in 64 children with KD. The percentage distribution of lymphocyte subgroups and the altered neutrophil lymphocyte ratio demonstrated that the inflammatory response was dominated by the B cell-mediated humoral immune response before intravenous immunoglobulin (IVIG) treatment, but mainly by T cells via cellular cytotoxic effects after IVIG treatment. Among the different types of inflammatory cytokines, the results of the present study revealed that the altered levels of interleukin-2 receptor (IL-2R) and interleukin-10 (IL-10) were closely associated with the percentage of CD8+ T cells and CD19+ B cells. Additionally, the two cytokines exhibited more sensitive fluctuations based on the status of the children with KD in various circumstances compared with other indexes, such as the percentages of CD8+ T cells and CD19+ B cells or the PLT count. These results suggested that children with KD who are ≥4 years old may benefit from IVIG but will not benefit from decreased platelet activation or suffer less cardiovascular complications. Additionally, starting clopidogrel usage earlier as an antiplatelet strategy should be considered based on the observed continuous rise in the PLT count in children with KD receiving IVIG. In conclusion, dynamically monitoring the levels of IL-2R and IL-10 has the potential to provide indications of the intensity and development of the inflammatory response in children with KD and may contribute to the early prediction and adjustment of pathological and pharmacological effects of therapy.

Systemic Inflammation May Induce Cardiac Injury in COVID-19 Patients Including Children and Adolescents Without Underlying Cardiovascular Diseases: A Systematic Review

Coronavirus disease 2019(COVID-19) is an ongoing global pandemic with a daily increasing number of affected individuals and a relatively high mortality rate. COVID-19 patients that develop cardiac injury are at increased risk of a worse clinical course with higher rates of mortality. Increasing amounts of evidence suggest that a system-wide inflammatory response and a cytokine storm mediated type syndrome plays a crucial role in disease progression. This systematic review investigates the possible role of hyperinflammation in inducing cardiac injury as one of the severe complications of COVID-19. A systematic literature search was performed using PubMed, Embase and Scopus databases to identify relevant clinical studies that investigated cardiovascular injury manifestations and reported inflammatory and cardiac biomarkers in COVID-19 patients. Only 29 studies met our inclusion criteria and the majority of these studies demonstrated significantly elevated inflammatory and cardiac blood markers. It was evident that underlying cardiovascular diseases may increase the risk of developing cardiac injury. However, many COVID-19 patients included in this review, developed different types of cardiac injury without having any underlying cardiovascular diseases. Furthermore, many of these patients were either children or adolescents. Therefore, age and comorbidities may not always be the two main risk factors that dictate the severity and outcome of COVID-19. Further investigations are required to understand the underlying mechanisms of pathogenicity as an urgent requirement to develop the appropriate treatment and prevention strategies. These strategies may specifically target hyperinflammation as a suspected driving factor for some of the severe complications of COVID-19.

Immune-modulatory effect of human milk in reducing the risk of Kawasaki disease: A nationwide study in Korea

BACKGROUND

Kawasaki disease (KD) is the most common acquired heart disease among children in developed countries, but the etiology is still unclear. There are several hypotheses regarding the outbreak of KD, including infection, genetics, and immunity. Since breastfeeding plays an essential role in the immune system's composition, investigating breastfeeding's effects on the occurrence of KD would be an excellent way to identify the etiology of KD.

AIM

To determine whether the incidence of KD decreases with breastfeeding.

METHODS

This nationwide cohort study analyzed data from the National Health Insurance Service (NHIS) in South Korea and included 1,910,438 infants who underwent their first National Children's Health Examination (NCHE) between 2008 and 2014. Feeding types were collected using a questionnaire in NCHE. The NHIS data and NCHE data were merged and analyzed. First, we investigated the effect of breastfeeding on the development of KD at 1 year of age. Then, we surveyed the age at which no significant effect appeared by expanding the observation range yearly.

RESULTS

The most prevalent feeding type in the study population was exclusive breastfeeding (41.5%). At 10-12 months of follow-up age, 3,854 (0.2%) infants were diagnosed with KD. Compared to the exclusive formula feeding group, the adjusted odds ratio (aOR) for KD was 0.84 [95% confidence interval (CI), 0.78-0.90] and 0.86 (95% CI, 0.79-0.94) in the exclusive and partial breastfeeding groups, respectively. At 22-24 months of age, aOR for KD was 0.94 (95% CI, 0.90-0.98) in the exclusive breastfeeding group and 0.98 (95% CI, 0.92-1.03) in the partial breastfeeding group. There was no difference in the risk between the groups at 34-36 months.

CONCLUSIONS

Using a large amount of national data on children aged <2 years, we proved that breastfeeding has a protective effect on the development of KD.

Spatiotemporal clusters of Kawasaki disease in South Korea from 2008 to 2017: A municipal-level ecological study

INTRODUCTION

As the etiology of Kawasaki disease (KD) remains unknown, identifying spatiotemporal clusters with proper stratification of KD could provide further evidence for investigating the triggers of KD. However, spatiotemporal distributions of KD with sex stratification have never been reported. Therefore, we aimed to analyze the spatiotemporal patterns of KD by sex in South Korea.

METHODS

We extracted epidemiologic week (Epiweek)-based KD cases in patients <5 years of age (ICD-10-CM code: M303) from 2008 to 2017 national health insurance service data at the 250 municipal level. To determine whether spatial autocorrelation and persistent municipal-level clusters exist, year- and sex-stratified global Moran's I statistics, Getis-Ord Gi* statistics, and emerging hotspot analysis on KD incidence were conducted.

RESULTS

A total of 72,510 KD cases were reported between 2008 and 2017 (male-to-female ratio = 1.40:1). Incidence has increased since 2008, with the highest incidence in 2016 (396.8 per 100,000 population). KD had seasonality of winter and summer but different by sex. Positive spatial autocorrelation was consistently reported in every stratum, with the 2011-2014 period having the strongest index value (total sex I = 0.286, p < 0.001; male I = 0.242, p < 0.001; female I = 0.213, p < 0.001). Hot spots were consistently detected in the northern parts, and cold spots were in the southern part for 9 years in both sexes. The emerging hot spot analysis showed new, consecutive, and sporadic hot spots on the northwestern and eastern coasts and new and sporadic cold spots in the southwestern part. However, the distribution and proportion of hot or cold spot types differed according to sex.

DISCUSSION

The spatiotemporal features of KD had limits to concluding that only infectious triggers result in KD occurrence. Therefore, our findings support the notion that KD is a syndrome with multiple factors, including infectious, genetic, and environmental factors, that are associated with sex differences.

Kawasaki disease in Malaysia: Biochemical profile, characterization, diagnosis and treatment

INTRODUCTION

Kawasaki disease (KD) is an acute idiopathic systemic vasculitis with a self- limiting course that predominantly affects children under 5 years old, particularly in the East Asian countries. Nevertheless, to date, the data on KD in Malaysia are limited. This study aimed to evaluate the epidemiology, clinical features, treatment, and outcomes of KD among the pediatric patients admitted to Hospital Canselor Tunku Muhriz (HCTM), Kuala Lumpur, Malaysia.

METHOD

A retrospective cohort study of 66,500 pediatric patients presented at HCTM from the year 2004 to 2021 was conducted.

RESULTS

62 KD cases out of 66,500 pediatric admissions were reported, with a male-to-female ratio of 1.58 to 1. Majority of KD patients (95.0%) were younger than 5 years old. Prior infection was reported in 5 KD patients (8.1%). Apart from the classical features, manifestations of various organ systems including cardiovascular (16.1%), gastrointestinal (43.5%), neurological (1.61%), musculoskeletal (1.61%), and genitourinary (17.7%) systems were observed. There was a significant association between sterile pyuria and coronary artery aneurysm (CAA) (p < 0.05). Interestingly, abnormal liver parameters (p < 0.05) and incomplete KD (p < 0.05) were significantly related to IVIG resistance.

DISCUSSION

The presence of family history, immunological disorder, and previous infection in our KD patients suggested that there is a possibility of genetic, immunological, and infectious roles in the pathophysiology of KD. IVIG resistance is more likely to occur in KD patients with hepatic dysfunction or incomplete KD presentation. These findings highlighted the significant contribution of laboratory parameters to the prognosis of KD, prompting more in-depth research on the KD scoring systems and their relevance in this country.

Association study of miR-149, miR-196a2, and miR-499a polymorphisms with coronary artery aneurysm of Kawasaki disease in southern Chinese population

Background

Accumulating evidence suggests that several microRNA (miRNA) polymorphisms are closely associated with disease susceptibility or progression, such as in Kawasaki disease (KD). Our previous studies revealed the association of miR‐149 rs2292832 T>C and miR‐196a2 rs11614913 C>T polymorphisms with KD susceptibility. The present study further focused on the relationship between three miRNA polymorphisms (miR‐149 rs2292832 T>C, miR‐196a2 rs11614913 C>T and miR‐499a rs3746444 A>G) and the risk of coronary artery aneurysm (CAA) in southern Chinese KD patients.

Methods

We evaluated 318 KD patients with CAAs and 784 patients without CAAs. TaqMan assays were used to estimate genotyping and analyze the relationship between miRNA polymorphisms (miR‐149 rs2292832 T>C, miR‐196a2 rs11614913 C>T and miR‐499a rs3746444 A>G) and risk associations of CAA by odds ratios (ORs) and 95% confidence intervals (CIs).

Results

We found that the miR‐149 rs2292832 TC/CC genotype increased the CAA risk (adjusted OR = 1.53, 95% CI = 1.15–2.03, p = 0.003 for TC, adjusted OR = 1.63, 95% CI = 1.08–2.47, p = 0.021 for CC), whereas the miR‐499a rs3746444 AG genotype decreased the CAA risk in KD patients (adjusted OR = 0.33, 95% CI = 0.25–0.45 p ≤ 0.001). Moreover, patients carrying two or three of these single nucleotide polymorphism (SNP) genotypes (rs2292832 TC/CC and rs11614913 TT and rs3746444 AA) had a higher risk for CAA than those who harbored only zero or one of these SNP genotypes.

Conclusions

Our results demonstrated that the miR‐149 rs2292832 T>C polymorphism increased the risk of CAA in KD patients and that the miR‐499a rs3746444 A>G polymorphism decreased the risk of CAA in KD patients. Further studies with larger sample sizes and different centers are needed to confirm the findings of the present study.

CASP5 and CR1 as potential biomarkers for Kawasaki disease: an Integrated Bioinformatics-Experimental Study

BACKGROUND

Kawasaki disease (KD) is a pediatric inflammatory disorder causes coronary artery complications. The disease overlapping manifestations with a set of symptomatically like diseases such as bacterial and viral infections, juvenile idiopathic arthritis, Henoch-Schönlein purpura, infection of unknown etiology, group-A streptococcal and adenoviral infections, and incomplete KD could lead to misdiagnosis of the disease.

METHODS

In the present study, we applied weighted gene co-expression network analysis (WGCNA) to identify network modules of co-expressed genes in GSE73464 and also, limma package was used to identify the differentially expressed genes (DEGs) in KD expression arrays composed of GSE73464, GSE18606, GSE109351, and GSE68004. By merging the results of WGCNA and limma, we detected hub genes. Then, analyzed the peripheral blood mononuclear cells (PBMCs) of 16 patients and 8 control subjects using Real-Time Polymerase Chain Reaction (RT-PCR) to evaluate the previous results.

RESULTS

We assessed the diagnostic potency of the screened genes by plotting the area under curve (AUC). We finally identified 2 genes CASP5(Caspase 5) and CR1(Complement C3b/C4b Receptor 1) which were shown to potentially discriminate KD from other similar diseases and also from healthy people.

CONCLUSIONS

The results of RT-PCR and AUC confirmed the diagnostic potentials of two suggested biomarkers for KD.

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.

Non-SARS, non-MERS human coronavirus infections and risk of Kawasaki disease: a meta-analysis

Aim: To study the association between non-SARS, non-MERS human coronavirus (HCoV) infections and Kawasaki disease (KD). Methods: Meta-analysis of observational studies published until 1 May 2021. Results: Out of 571 papers retrieved through database search, 10 provided data of 17,732 children. Age ranged from 2 months-14.9 years with 66% being male and 71% being complete KD. Compared with controls, there was an increased risk of developing KD in those detected to have HCoV infection (OR: 2.3 [95% CI: 1.06-4.99]; p = 0.03). The GRADE evidence for all outcomes was of 'low-certainty'. Conclusion: A 'low certainty' of evidence suggests an increased risk of KD in children infected with HCoV. We need multi-center, prospective studies to support or refute this finding. PROSPERO protocol registration: CRD42021251582.

Kawasaki Disease and Pediatric Infectious Diseases During the Coronavirus Disease 2019 Pandemic

OBJECTIVE

To assess the epidemiologic association between Kawasaki disease and common pediatric infectious diseases (PIDs) identified during the coronavirus disease 2019 (COVID-19) pandemic period to confirm whether the infection-triggered theory is a plausible hypothesis for the pathogenesis of Kawasaki disease.

STUDY DESIGN

A retrospective epidemiologic study was conducted using datasets obtained from Web-based surveillance of Kawasaki disease and PIDs in Japan. We compared weekly numbers of patients who developed Kawasaki disease and specific PIDs between 2020 and 2017-2019 and evaluated the association between the percent reduction in the number of patients with these diseases.

RESULTS

A total of 868 patients developed Kawasaki disease in 2020. During the social distancing period in 2020, the number of patients with Kawasaki disease was approximately 35% lower than in 2017-2019. Time from the onset of Kawasaki disease until the first hospital visit did not differ significantly among the examined years. The proportion of older children with Kawasaki disease decreased more than that of infants with Kawasaki disease (age <1 year), resulting in a significant difference in the proportion of infant patients between 2020 and 2017-2019 (24% vs 19%; P < .01). The number of patients with incomplete Kawasaki disease was unchanged from that of previous years. The weekly percent reduction in patient numbers differed between Kawasaki disease and PIDs during 2020, with no strong correlation between the 2 diseases.

CONCLUSIONS

Our data indicate that parents of patients with Kawasaki disease did not avoid hospital visits during the COVID-19 pandemic period. The findings indicate the possibility that triggering Kawasaki disease might be associated with presently unidentified respiratory pathogen(s) that potentially might be acquired from both within and outside the household.

Co-culture of peripheral blood mononuclear cell (PBMC) and human coronary artery endothelial cell (HCAEC) reveals the important role of autophagy implicated in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis syndrome that commonly occurs in children. Autophagy has been increasingly shown to be involved in various cardiovascular diseases, including endothelial dysfunction and vascular endothelial injury. However, whether autophagy is implicated in the pathogenesis of KD remains poorly understood, and particularly, how the dysfunction of human coronary artery endothelial cells (HCAECs) is associated with autophagy in peripheral blood mononuclear cells (PBMCs) from KD patients awaits further investigation.

METHODS

Peripheral blood samples were collected from KD patients, common fever patients, and healthy controls. The PBMC samples were isolated from KD blood samples collected at three different phases: the acute phase before therapy (acute-KD), 1 week (subacute-KD), and 4 weeks (convalescent-KD) after drug administration.

RESULTS

The autophagy flux was significantly increased in the PBMCs of KD patients at acute phase. The PBMCs of acute KD patients could induce autophagy in HCAECs and promote the secretion of chemokines and pro-inflammatory factors after cocultured with HCAECs whereas 3-methyladenine (3-MA) drug could partly reverse this process.

CONCLUSIONS

Autophagy is involved in the inflammatory injury of vascular endothelial cells associated with PBMCs in KD patients, and may play a crucial role in regulating inflammation. Hence, we identify a novel regulatory mechanism of vascular injury in this disease.

The Immunopathobiology of SARS-CoV-2 Infection

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to coronavirus disease 2019 (COVID-19). Virus-specific immunity controls infection, transmission and disease severity. With respect to disease severity, a spectrum of clinical outcomes occur associated with age, genetics, comorbidities and immune responses in an infected person. Dysfunctions in innate and adaptive immunity commonly follow viral infection. These are heralded by altered innate mononuclear phagocyte differentiation, activation, intracellular killing and adaptive memory, effector, and regulatory T cell responses. All of such affect viral clearance and the progression of end-organ disease. Failures to produce effective controlled antiviral immunity leads to life-threatening end-organ disease that is typified by the acute respiratory distress syndrome. The most effective means to contain SARS-CoV-2 infection is by vaccination. While an arsenal of immunomodulators were developed for control of viral infection and subsequent COVID-19 disease, further research is required to enable therapeutic implementation.

Resveratrol alleviates Kawasaki disease-induced myocardial injury via inhibition of apoptosis and autophagy

OBJECTIVES

To explore the effect of resveratrol (Res) on Kawasaki disease (KD)-induced myocardial injury and to evaluate its effect on apoptosis and autophagy.

METHODS

Forty-eight juvenile male Sprague Dawley rats were randomly divided into a control group, a Res group, a lactobacillus casei cell wall extract (LCWE)-induced Kawasaki disease group (KD group), and a LCWE-induced Kawasaki disease + Res treatment group (Res+KD group). The control group was intraperitoneally injected with saline. The Res group was intraperitoneally injected with resveratrol (100 mg/kg). The KD group was intraperitoneally injected with 0.5 mL LCWE (1 mg/mL). The Res+KD group was intraperitoneally injected with 0.5 mL LCWE (1 mg/mL) and resveratrol (100 mg/kg). After 4 weeks, the left ventricular ejection fraction (LVEF) and short axis shortening rate (LVFS) were detected by echocardiography. The apoptotic rate was detected by terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) staining. The levels of B-cell lymphoma-2 (Bcl-2), Bcl-2-associated X protein (Bax), microtubule-associated protein 1 light chain 3β (LC3B), Beclin-1, autophagy related 5 (Atg5) and sequestosome-1 (p62) were detected by Western blotting. The formation of autophagosome was observed under transmission electron microscope.

RESULTS

There was no significant difference in the above-mentioned indexes between the control group and the Res group (all P>0.05). Compared with the control group, the values of LVEF and LVFS were significantly decreased in the KD group (both P<0.01); the ratio of Bax/Bcl-2 and TUNEL-positive cells were increased (both P<0.01); the LC3BII/LC3BI ratio, the levels of Beclin 1, Atg5 and p62, and the number of autophagosomes were also significantly increased in KD group (all P<0.01). Compared with the KD group, the values of LVEF and LVFS were significantly increased, the ratio of Bax/Bcl-2 and TUNEL-positive cells were decreased, the LC3BII/LC3BI ratio, the levels of Beclin 1, Atg5 and p62 were all decreased (all P<0.01), and the number of autophagosomes was suppressed.

CONCLUSIONS

Res can attenuate the KD-induced myocardial injury via inhibiting the apoptosis and autophagy.

Current Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome in Children

Purpose of Review

We highlight the new clinical entity multisystem inflammatory syndrome in children (MIS-C), the progress in understanding its immunopathogenesis, and compare and contrast the clinical and immunologic features of MIS-C with Kawasaki disease (KD).

Recent Findings

Studies show immune dysregulation in MIS-C including T lymphocyte depletion and activation, T cell receptor Vbeta skewing, elevated plasmablast frequencies, increased markers of vascular pathology, and decreased numbers and functional profiles of antigen-presenting cells.

Summary

MIS-C is a late manifestation of infection with SARS-CoV-2 associated with marked immune activation and many potential mechanisms of immunopathogenesis. MIS-C and KD have clinical similarities but are distinct. Myocardial dysfunction with or without mild coronary artery dilation can occur in MIS-C but generally corrects within weeks. In contrast, the coronary arteries are the primary target in KD, and coronary artery sequelae can be lifelong. Supportive care and anti-inflammatory therapy appear to hasten improvement in children with MIS-C, and there is hope that vaccines will prevent its development.

Multisystem Inflammatory Syndrome with Features of Atypical Kawasaki Disease during the COVID-19 Pandemic

Background

Although Kawasaki disease (KD) is the most common self-limited systemic vasculitis in pediatrics, the exact etiology of the disease, its association with other diseases, and pathogens is still unknown. In order to achieve a better understanding and management of the disease, documentation and reporting of atypical cases is justified, particularly with the growing number of children with inflammatory syndrome with clinical features simulating KD during the COVID-19 pandemic. Here, we present a case of an atypical case of KD presenting as multisystem inflammatory syndrome (MIS) during the COVID-19 pandemic. Case Presentation. The patient is a 7-year-old girl who developed fever (39°C) and erythematous multiform rash on the abdomen and along with erythema and edema on the extremities. Laboratory evaluation revealed neutrophilia and lymphopenia along with elevated C-reactive protein, erythrocyte sedimentation rate, troponin, lactate dehydrogenase, ferritin, and D-dimer. Although the patient did not fulfill the KD criteria, based on approved guidelines and approaches regarding atypical KD and multisystem inflammatory syndrome in children (MIS-C) during the COVID-19 pandemic, intravenous immunoglobulin along with aspirin was administered for the patients. The patient's symptoms resolved with an uneventful postdischarge course.

Conclusion

Early diagnosis and treatment of patients meeting full or partial criteria for KD are critical to preventing end-organ damage and other long-term complications, especially during times of public crisis and global health emergencies, such as the novel coronavirus pandemic.

Recent Advances in Pediatric Vasculitis

This article provides an overview of the clinical presentation and diagnosis of select pediatric primary systemic vasculitides. Important advances in understanding the pathogenesis of these rare diseases also are discussed and efforts to harmonize treatment through consensus-based guidelines and multicenter and international collaborations highlighted.

Multisystem Inflammatory Syndrome Following SARS-CoV-2 Infection in Children: One Year after the Onset of the Pandemic in a High-Incidence Area

SARS-CoV-2 infection in children can trigger cardiovascular manifestations potentially requiring an intensive treatment and defining a new entity named Multisystem Inflammatory Syndrome in Children (MIS-C), whose features partially overlap with Kawasaki Disease (KD). A cross-sectional study including all diagnoses of MIS-C and KD from April 2020 to May 2021 in our metropolitan area was conducted evaluating clinical, laboratory (including immunological response, cytokines, and markers of myocardial damage), and cardiac (coronary and non-coronary) features at onset of the diseases. Evolution of ventricular dysfunction, valve regurgitations, and coronary lesions was documented. The severity of the disease was also considered based on the need for inotropic support and ICU admission. Twenty-four MIS-C were diagnosed (14 boys, median age 82 months): 13/24 cases (54.17%) presented left ventricular dysfunction, 12/24 (50%) required inotropic support, and 10/24 (41.67%) developed coronary anomalies (CALs). All patients received steroids and IVIG at a median time of 5 days (IQR1:4, IQR3:6.5) from onset of fever and heart function normalized 6 days (IQR1: 5, IQR3: 7) after therapy, while CALs persisted in one. One patient (12.5%) required infliximab because of refractory disease and still presented CALs 18 days after therapy. During the same study period, 15 KD were diagnosed: none had ventricular dysfunction, while 7/15 (46.67%) developed CALs. Three out of 15 patients (20%) still presented CALs 46 days from onset. Compared to KD, MIS-C pts have significantly higher IL8 and similar lymphocytes subpopulations. Despite a more severe presentation and initial cardiac findings compared to KD, the myocardial injury in MIS-C has a rapid response to immunomodulatory treatment (median time 6 days), in terms of ventricular function, valve regurgitations, and troponin. Incidence of CALs is similar at onset, but it tends to regress in most of the cases of MIS-C differently than in KD where CALs persist in up to 40% in the subacute stage after treatment.

Kawasaki Disease Shock Syndrome vs Classical Kawasaki Disease: A Meta-analysis and Comparison With SARS-CoV-2 Multisystem Inflammatory Syndrome

BACKGROUND

The emergence of increasing reports worldwide of a severe inflammatory process and shock in pediatric patients resembling Kawasaki disease (KD)-and, more specifically, Kawasaki disease shock syndrome (KDSS)-prompted us to explore KDSS in a preamble of a systematic comparison between the 2 conditions.

METHODS

We completed a systematic review of KDSS and performed a meta-analysis comparison between reported KDSS cases and KD controls.

RESULTS

A total of 10 case-control series were included in the meta-analysis. Patients with KDSS were older (38.4 ± 30.6 vs 21.9 ± 19.5 months; P < 0.001) compared with standard KD with equal sex distribution and completeness of clinical diagnostic criteria. KDSS present higher C-reactive protein (59.4 ± 29.2 mg/dL vs 20.8 ± 14.8 mg/dL; P < 0.001), lower albumin (2.7 ± 0.5 g/dL vs 3.3 ± 0.5 g/dL; P < 0.01), and lower platelets (255 ± 149 109/L vs 394 ± 132 109/L; P < 0.001) but only borderline higher white blood cells (P = 0.06). Differences in alanine transaminase, aspartate aminotransferase, and erythrocyte sedimentation rate were nonsignificant. The odds of intravenous immunoglobulin resistance (44.4% vs 9.6%; (P < 0.001) and the hospital length of stay (10.9 ± 5.8 vs 5.0 ± 3.0 days; P < 0.001) were higher in KDSS, as were the odds of coronary-artery abnormalities (33.9% vs 8.6%; P < 0.001).

CONCLUSIONS

This first meta-analysis on KDSS vs KD represents a basis for future works on KDSS and opens the opportunity for future multicentre studies in the search of causal relationships between presenting elements and the eventual complications of KDSS. The similarities between SARS-CoV-2 multisystem inflammatory syndrome in children and KDSS open new horizons to the understanding of the etiology and pathophysiology related to KDSS.

Pediatric Kawasaki Disease Trends Prior to and During COVID-19 Outbreak in Singapore

Kawasaki disease (KD, typical/atypical/partial) admissions (n = 644) were surveyed from 2017 to 2020 and compared to urinary tract infection (UTI) admissions and COVID-19 in 2020. KD admissions decreased by 27% and median KD age decreased in 2020, whereas UTI admissions remained steady. KD admissions showed a seasonality with a peak in April and nadir in February-March. All KD/KD-related pediatric intensive care unit cases tested negative for COVID-19, and no multisystem inflammatory syndrome in children was found.