Heat shock proteins and superantigenic properties of bacteria from the gastrointestinal tract of patients with Kawasaki disease

Association of Previous Antibiotics Use and Kawasaki Disease: A Cohort Study of 106,908 Patients

BACKGROUND

Microbial imbalance in the gut from antibiotic use may be an etiologic factor of Kawasaki disease (KD). We aimed to identify the association between the use of antibiotics and the development of KD, considering various antibiotic profiles.

METHODS

A population-based, case-control study was performed using data from the Health Insurance Review and Assessment Service database. Children <5 years of age, who were diagnosed with KD between 2016 and 2019, were identified. Propensity score-matched controls were selected from the general population in a 1:5 ratio. Four separate study cohorts were created according to different periods of antibiotic use: (1) within 28 days and (2) 12 months after birth and (3) within 6 months and (4) 12 months from the index date. Profiles regarding antibiotic use were compared between patients with KD and matched controls.

RESULTS

We included 17,818 patients with KD and 89,090 matched controls. Use of antibiotics within 6 months [odds ratio (OR): 1.18; 95% confidence interval (CI): 1.12-1.26] and 12 months (OR: 1.23; 95% CI: 1.14-1.32) from the index date were associated with the development of KD. The association between antibiotic use and KD was most prominent in patients who had received 3 or more types of antibiotics within 12 months from the index date (OR: 1.26; 95% CI: 1.17-1.37).

CONCLUSIONS

Antibiotic use within the preceding 6 or 12 months was associated with KD. Alteration in gut microbiota due to antibiotic usage might play a role in the development of KD.

The intestinal microbiota contributes to the development of immune-mediated cardiovascular inflammation and vasculitis in mice

Alterations in the intestinal microbiota contribute to the pathogenesis of various cardiovascular disorders, but how they affect the development of Kawasaki disease (KD), an acute pediatric vasculitis, remains unclear. We report that depleting the gut microbiota reduces the development of cardiovascular inflammation in a murine model mimicking KD vasculitis. The development of cardiovascular lesions was associated with alterations in the intestinal microbiota composition and, notably, a decreased abundance of Akkermansia muciniphila and Faecalibacterium prausnitzii. Oral supplementation with either of these live or pasteurized individual bacteria, or with short-chain fatty acids (SCFAs) produced by them, attenuated cardiovascular inflammation. Treatment with Amuc_1100, the TLR-2 signaling outer membrane protein from A. muciniphila , also decreased the severity of vascular inflammation. This study reveals an underappreciated gut microbiota-cardiovascular inflammation axis in KD vasculitis pathogenesis and identifies specific intestinal commensals that regulate vasculitis in mice by producing metabolites or via extracellular proteins acting on gut barrier function.

IN BRIEF

It remains unclear whether changes in the intestinal microbiota composition are involved in the development of cardiovascular lesions associated with Kawasaki disease (KD), an immune-mediated vasculitis. Jena et al. observe alterations in the intestinal microbiota composition of mice developing vasculitis, characterized by reduced A. muciniphila and F. prausnitzii . Oral supplementation with either of these bacteria, live or pasteurized, or with bacteria-produced short-chain fatty acids (SCFAs) or Amuc_1100, the TLR-2 signaling outer membrane protein of A. muciniphila , was sufficient to alleviate the development of cardiovascular lesions in mice by promoting intestinal barrier function.

HIGHLIGHTS

Absence or depletion of the microbiota decreases the severity of vasculitis in a murine model mimicking KD vasculitis. Supplementation of B. wadsworthia and B. fragilis promotes murine KD vasculitis. Decreased abundances of F. prausnitzii and A. muciniphila are associated with the development of cardiovascular lesions in mice. Supplementation with either live or pasteurized A. muciniphila and F. prausnitzii, or the TLR-2 signaling Amuc_1100, reduces the severity of vasculitis by promoting gut barrier function.

Interplay between the Chaperone System and Gut Microbiota Dysbiosis in Systemic Lupus Erythematosus Pathogenesis: Is Molecular Mimicry the Missing Link between Those Two Factors?

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease characterized by self-immune tolerance breakdown and the production of autoantibodies, causing the deposition of immune complexes and triggering inflammation and immune-mediated damage. SLE pathogenesis involves genetic predisposition and a combination of environmental factors. Clinical manifestations are variable, making an early diagnosis challenging. Heat shock proteins (Hsps), belonging to the chaperone system, interact with the immune system, acting as pro-inflammatory factors, autoantigens, as well as immune tolerance promoters. Increased levels of some Hsps and the production of autoantibodies against them are correlated with SLE onset and progression. The production of these autoantibodies has been attributed to molecular mimicry, occurring upon viral and bacterial infections, since they are evolutionary highly conserved. Gut microbiota dysbiosis has been associated with the occurrence and severity of SLE. Numerous findings suggest that proteins and metabolites of commensal bacteria can mimic autoantigens, inducing autoimmunity, because of molecular mimicry. Here, we propose that shared epitopes between human Hsps and those of gut commensal bacteria cause the production of anti-Hsp autoantibodies that cross-react with human molecules, contributing to SLE pathogenesis. Thus, the involvement of the chaperone system, gut microbiota dysbiosis, and molecular mimicry in SLE ought to be coordinately studied.

Retrospective evaluation of 130 cases with kawasaki disease follow-up in a tertiary care center in Turkey between 1999 and 2019: a 20-year experience

OBJECTIVES

Kawasaki disease (KD), which is a medium vessel vasculitis, is common in Asian countries and is the most common cause of childhood-acquired heart diseases in developed countries. However, disease course and epidemiological data are limited in non-Asian developing countries like ours. We aimed to evaluate the clinical features and prognosis of patients with KD in our country and ethnicity, one of the referee centers of our country.

METHODS

Patients with KD in our center for the last 20 years in the pre-COVID-19 pandemic era were included in the study. The clinical and laboratory findings, treatments, and follow-up findings were reviewed retrospectively in different age groups.

RESULTS

Of the 130 patients, 82 (63%) were male. The median age at diagnosis was 2.97 years (2 months-11.5 years). Thirty-six (27.7%) patients were diagnosed with incomplete KD, and there was no significant laboratory difference between incomplete KD and complete KD patients. Thirty-three (25.3%) patients had coronary artery lesions (CAL), and it persisted in only 3 of 33 patients. One of 15 patients with IVIG resistance had CAL. The independent risk factors were days of illness at initial IVIG administration for CAL (p = 0.013, OR [95%CI] = 1.20 [1.04-1.38]) and low hemoglobin (p = 0.003, OR [95%CI] = 0.51 [0.33-0.79]) and low sodium for IVIG resistance (p = 0.012, OR [95%CI] = 0.81[0.69-0.95]).

CONCLUSIONS

The rate of CAL is approximately three times higher in our results than in the Japanese data in recent years. We showed that the time of IVIG administration is the most critical factor for preventing CAL. Wide-ranging studies are needed to decently predict the disease process according to the age and region of patients.

Risk factors and an early predictive model for Kawasaki disease shock syndrome in Chinese children

BACKGROUND

Kawasaki disease shock syndrome (KDSS), though rare, has increased risk for cardiovascular complications. Early diagnosis is crucial to improve the prognosis of KDSS patients. Our study aimed to identify risk factors and construct a predictive model for KDSS.

METHODS

This case-control study was conducted from June, 2015 to July, 2023 in two children's hospitals in China. Children initially diagnosed with KDSS and children with Kawasaki disease (KD) without shock were matched at a ratio of 1:4 by using the propensity score method. Laboratory results obtained prior to shock syndrome and treatment with intravenous immunoglobulin were recorded to predict the onset of KDSS. Univariable logistic regression and forward stepwise logistic regression were used to select significant and independent risk factors associated with KDSS.

RESULTS

After matching by age and gender, 73 KDSS and 292 KD patients without shock formed the development dataset; 40 KDSS and 160 KD patients without shock formed the validation dataset. Interleukin-10 (IL-10) > reference value, platelet counts (PLT) < 260 × 109/L, C-reactive protein (CRP) > 80 mg/ml, procalcitonin (PCT) > 1ng/ml, and albumin (Alb) < 35 g/L were independent risk factors for KDSS. The nomogram model including the above five indicators had area under the curves (AUCs) of 0.91(95% CI: 0.87-0.94) and 0.90 (95% CI: 0.71-0.86) in the development and validation datasets, with a specificity and sensitivity of 80% and 86%, 66% and 77%, respectively. Calibration curves showed good predictive accuracy of the nomogram. Decision curve analyses revealed the predictive model has application value.

CONCLUSIONS

This study identified IL-10, PLT, CRP, PCT and Alb as risk factors for KDSS. The nomogram model can effectively predict the occurrence of KDSS in Chinese children. It will facilitate pediatricians in early diagnosis, which is essential to the prevention of cardiovascular complications.

Advancing lifelong precision medicine for cardiovascular diseases through gut microbiota modulation

The gut microbiome is known as the tenth system of the human body that plays a vital role in the intersection between health and disease. The considerable inter-individual variability in gut microbiota poses both challenges and great prospects in promoting precision medicine in cardiovascular diseases (CVDs). In this review, based on the development, evolution, and influencing factors of gut microbiota in a full life circle, we summarized the recent advances on the characteristic alteration in gut microbiota in CVDs throughout different life stages, and depicted their pathological links in mechanism, as well as the highlight achievements of targeting gut microbiota in CVDs prevention, diagnosis and treatment. Personalized strategies could be tailored according to gut microbiota characteristics in different life stages, including gut microbiota-blood metabolites combined prediction and diagnosis, dietary interventions, lifestyle improvements, probiotic or prebiotic supplements. However, to fulfill the promise of a lifelong cardiovascular health, more mechanism studies should progress from correlation to causality and decipher novel mechanisms linking specific microbes and CVDs. It is also promising to use the burgeoning artificial intelligence and machine learning to target gut microbiota for developing diagnosis system and screening for new therapeutic interventions.

Emerging evidence of microbial infection in causing systematic immune vasculitis in Kawasaki disease

Kawasaki disease (KD) is a systematic vasculitis that is often complicated by coronary artery lesions and is a leading cause of acquired heart disease in developed countries. Previous studies have suggested that genetic susceptibility, together with an inducing infectious agent, could be involved in KD pathogenesis; however, the precise causative agent of this disease remains unknown. Moreover, there are still debates concerning whether KD is an infectious disease or an autoimmune disease, although many studies have begun to show that various pathogens functioning as critical inducers could activate different kinds of immune cells, consequently leading to the dysfunction of endothelial cells and systematic vasculitis. Here in this review, we attempt to summarize all the available evidence concerning pathogen infections associated with KD pathogenesis. We also discuss the related mechanisms, present a future perspective, and identify the open questions that remain to be investigated, thereby providing a comprehensive description of pathogen infections and their correlations with the host immune system in leading to KD.

Gut microbiota and transcriptome response of earthworms (Metaphire guillelmi) to polymyxin B exposure

Polymyxin B (PMB) has received widespread attention for its use as a last-line therapy against multidrug-resistant bacterial infection. However, the consequences of unintended PMB exposure on organisms in the surrounding environment remain inconclusive. Therefore, this study investigated the effects of soil PMB residue on the gut microbiota and transcriptome of earthworms (Metaphire guillelmi). The results indicated that the tested doses of PMB (0.01-100 mg/kg soil) did not significantly affect the richness and Shannon's diversity index of the earthworm gut microbiota, but PMB altered its community structure and taxonomic composition. Moreover, PMB significantly affected Lysobacter, Aeromonas, and Sphingomonas in the soil microbiota, whereas Pseudomonas was significantly impacted the earthworm gut microbiota. Furthermore, active bacteria responded more significantly to PMB than the total microbial community. Bacterial genera such as Acinetobacter and Bacillus were highly correlated with differential expression of some genes, including up-regulated genes associated with folate biosynthesis, sulphur metabolism, and the IL-17 signalling pathway, and downregulated genes involved in vitamin digestion and absorption, salivary secretion, other types of O-glycan biosynthesis, and the NOD-like receptor signalling pathway. These results suggest that adaptation to PMB stress by earthworms involves changes in energy metabolism, their immune and digestive systems, as well as glycan biosynthesis. The study findings help elucidate the relationship between earthworms and their microbiota, while providing a reference for understanding the environmental risks of PMB.

Diagnosis, Progress, and Treatment Update of Kawasaki Disease

Kawasaki disease (KD) is an acute inflammatory disorder that primarily affects children and can lead to coronary artery lesions (CAL) if not diagnosed and treated promptly. The original clinical criteria for diagnosing KD were reported by Dr. Tomisaku Kawasaki in 1967 and have been used for decades. However, research since then has highlighted the limitations of relying solely on these criteria, as they might lead to underdiagnosis or delayed diagnosis, potentially increasing the risk of coronary artery complications. This review appears to discuss several important aspects related to KD diagnosis and management. The current diagnostic methods for KD might need updates, especially considering cases that do not fit the typical clinical criteria. Recognizing diagnostic pitfalls and distinguishing KD from other conditions that might have similar clinical presentations is essential. The differences and similarities between KD and Multisystem Inflammatory Syndrome in Children (MIS-C), another inflammatory condition that has been associated with COVID-19, were also reviewed. The review explores the potential role of eosinophil count, new biomarkers, microRNA panels, and scoring systems in aiding the diagnosis of KD. Overall, the review article provides a comprehensive overview of the evolving landscape of KD diagnosis and management, incorporating new diagnostic methods, biomarkers, and treatment approaches to improve patient outcomes and reduce the risk of complications.

Clinical features analysis of Kawasaki disease with abdominal symptoms as the first manifestation

To investigate the clinical characteristics of Kawasaki disease (KD) presenting with abdominal manifestation as the first manifestation. Our findings may help improve the cognition of KD with abdominal complications, and avoid misdiagnosis and missed diagnosis. A retrospective analysis was conducted of 1490 KD patients admitted to Shengjing Hospital between January 2019 and March 2022. Clinical characteristics, related factors, and prognosis of KD with abdominal manifestation as first manifestation were analyzed. Based on the presenting symptoms, patients were divided into gastrointestinal symptom group (n = 141), liver dysfunction group (n = 55), and control group (n = 1294). In the gastrointestinal group, diarrhea [100 cases (70.9%)], vomiting [55 cases (39.0%)], and abdominal pain [34 cases (24.1%)] were the most common symptoms at onset. 8 cases (5.7%) were complicated with pseudo-intestinal obstruction, 6 cases (4.3%) with ischemic colitis, 5 cases (3.5%) with pancreatitis, 2 cases (1.4%) with appendicitis, and 1 case (0.7%) with cholecystitis. Comparied to ordinary gastroenteritis caused by infection, gastroenteritis with KD has longer fever duration before treatment, higher WBC, PLT, CRP, AST levels and lower albumin levels. All patients in the liver dysfunction group had elevated transaminases, and 19 patients (34.5%) presented with jaundice. In the gastrointestinal group, the average hospital stay was 10.3 days, and the incidence of IVIG unresponsiveness and coronary artery lesion were 18.4% and 19.9%, respectively, which were significantly higher than that in the control group. In the liver dysfunction group, the average hospital stay (11.18 days), incidence of IVIG unresponsiveness (25.5%), and incidence of coronary artery lesion (29.1%) were significantly higher than that in the control group. On multivariate logistic regression analysis, gastrointestinal involvement, fever duration, ALT, PLT, and CRP were identified as risk factors for CAL, younger age, gastrointestinal involvement and fever duration were risk factors for IVIG unresponsiveness.  Conclusion: KD with gastrointestinal involvement is associated with a higher risk of IVIG unresponsiveness and coronary artery lesion. KD should be considered in the differential diagnosis of children with acute fever, especially those with gastrointestinal involvement and liver dysfunction. What is Known: • Fever duration, PLT, and CRP were identified as risk factors for CAL. Timely diagnosis and application of IVIG treatment can avoid exploratory laparotomy for ileus, appendectomy for misdiagnosed appendicitis, colonoscopy for misdiagnosed inflammatory bowel disease, and reduce the complications of CAL and IVIG unresponsiveness. What is New: • Abdominal symptoms as the first manifestation can be an independent risk factor for CAL and IVIG unresponsiveness. KD should be considered in the differential diagnosis of children with acute fever, especially those with gastrointestinal symptoms or liver dysfunction. • Gastroenteritis in KD group had longer fever duration before treatment, accompanied with higher WBC, PLT, CRP, AST levels and lower albumin levels than those gastroenteritis caused by infection. Therefore, high attention should be paid to the possibility of KD when gastroenteritis accompanied by along fever duration, high WBC, PLT, CRP, AST level or lowalbumin level.

Alteration of the oral and gut microbiota in patients with Kawasaki disease

Background

Kawasaki disease (KD) is a multi-systemic vasculitis that primarily affects children and has an unknown cause. Although an increasing number of studies linking the gut microbiota with KD, the unchallengeable etiology of KD is not available.

Methods

Here, we obtained fecal and oral samples from KD patients and healthy controls, and then we use high-throughput sequencing to examine the diversity and composition of microbiota.

Results

Results showed that both in the gut and oral microbiota, the diversity of KD patients was significantly lower than that of the healthy controls. In the gut microbiota, a higher abundance of Enterococcus (40.12% vs less than 0.1%), Bifidobacterium (20.71% vs 3.06%), Escherichia-Shigella (17.56% vs 0.61%), Streptococcus (5.97% vs 0.11%) and Blautia (4.69% vs 0.1%) was observed in the KD patients, and enrichment of Enterococcus in the patients was observed. In terms of oral microbiota, the prevalence of Streptococcus (21.99% vs 0.1%), Rothia (3.02% vs 0.1%), and Escherichia-Shigella (0.68% vs 0.0%) were significantly higher in the KD patients, with the enrichment of Streptococcus and Escherichia-Shigella. Additionally, significant differences in microbial community function between KD patients and healthy controls in the fecal samples were also observed, which will affect the colonization and reproduction of gut microbiota.

Conclusions

These results suggested that the dysbiosis of gut and oral microbiota are both related to KD pathogenesis, of which, the prevalence of Enterococcus in the gut and higher abundance of Streptococcus and Escherichia-Shigella in the oral cavity will be a potential biomarker of the KD. Overall, this study not only confirms that the disturbance of gut microbiota is a causative trigger of KD but also provides new insight into the oral microbiota involved in KD pathogenesis.

Seasonality and geographical distribution of Kawasaki disease among Black children in the Southeast United States

Introduction

Kawasaki Disease (KD) is a leading cause of pediatric acquired heart disease in the United States, affecting up to 7,000 children annually. Seasonal variation, an epidemiological characteristic of KD, has previously been reported predominantly among Asian children; however, little is known about the epidemiology and seasonality of KD of Black children within the U.S.

Methods

Electronic medical records were abstracted from 529 hospitalized KD patients admitted to a single tertiary center in Alabama between 2005 and 2019. Medical charts were reviewed to confirm KD diagnosis following American Heart Association criteria. Cases were stratified by the month of diagnosis date to assess seasonality, and statewide distribution of incidence is reported at county level using geographical spatial analysis. Comparisons were performed between Black patients and White patients with KD.

Results

The average number of KD cases per year was 35. Approximately, 60% were males and 44% were White children (N = 234), 45% were Black children (N = 240) and 11% were other races (N = 55). Black children were younger than White children at KD admission (median age 32 vs. 41 months respectively, p = 0.02). Overall, the highest rates of cases occurred between January and April. When stratifying by race, cases started to rise in December among White children with the highest rates between February and April with a peak in March. Among Black children cases were high during the winter season (January-April) with a peak in April. Similarly high rates also occurred in June, July and November. There were no differences in geographical distribution of cases by race.

Conclusion

KD incidence among White children in Alabama follows a seasonal cycle similar to other regions in the U.S. However, sustained incidence and additional peaks outside of the usual KD seasonality were seen among Black children with KD. Further studies are needed to investigate differential triggers between races.

Superantigens, a Paradox of the Immune Response

Staphylococcal enterotoxins are a wide family of bacterial exotoxins with the capacity to activate as much as 20% of the host T cells, which is why they were called superantigens. Superantigens (SAgs) can cause multiple diseases in humans and cattle, ranging from mild to life-threatening infections. Almost all S. aureus isolates encode at least one of these toxins, though there is no complete knowledge about how their production is triggered. One of the main problems with the available evidence for these toxins is that most studies have been conducted with a few superantigens; however, the resulting characteristics are attributed to the whole group. Although these toxins share homology and a two-domain structure organization, the similarity ratio varies from 20 to 89% among different SAgs, implying wide heterogeneity. Furthermore, every attempt to structurally classify these proteins has failed to answer differential biological functionalities. Taking these concerns into account, it might not be appropriate to extrapolate all the information that is currently available to every staphylococcal SAg. Here, we aimed to gather the available information about all staphylococcal SAgs, considering their functions and pathogenicity, their ability to interact with the immune system as well as their capacity to be used as immunotherapeutic agents, resembling the two faces of Dr. Jekyll and Mr. Hyde.

Analysis of multiple organ involvement in Kawasaki disease

This study aimed to explore the incidence and clinical characteristics of multiple complications in children with Kawasaki disease (KD). All patients were diagnosed in our hospital between January 2016 and December 2020. A total of 640 cases were included, 43 patients had coronary artery aneurysm, 51 patients had coronary artery dilation, and 546 patients had no coronary artery damage. The patients were divided into three subgroups based on age: < 1 year old, 1-5 years old, and > 5 years old. The multiple complications of all the KD children and the correlation between extracardiac complications and cardiovascular complications were analyzed. Among the 640 KD children, most were 1-5 years old (415/640, 64.8%). Children < 1 year old (31.6%) and > 5 years old (28.3%) were more likely to have cardiovascular complications. The incidence of respiratory complications was highest in 1-5 year olds (57.1%). Involvement of the digestive and the hematological systems gradually decreased with age, whereas involvement of the nervous system, the urinary system, and the joints gradually increased with age. The incidence of cardiovascular injury with extracardiac complications (22.3%) was higher than that without extracardiac complications (16.3%), although the difference was not statistically significant (p > 0.05).Conclusions: KD can be complicated by multiple-organ injury but there was no significant relationship between the occurrence of extracardiac complications and cardiovascular complications. What is Known: • Cardiovascular disease is generally believed to be the most common and serious complication of Kawasaki disease (KD). • Over recent years, we have found that extracardiovascular complications of KD are more common than generally supposed and, because they have some effect on prognosis, we believe that more attention should be paid to these complications. What is New: • There was no significant relationship between the occurrence of extracardiac complications and cardiovascular complications.

Multisystem inflammatory syndrome in children and Kawasaki disease: a critical comparison

Children and adolescents infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are predominantly asymptomatic or have mild symptoms compared with the more severe coronavirus disease 2019 (COVID-19) described in adults. However, SARS-CoV-2 is also associated with a widely reported but poorly understood paediatric systemic vasculitis. This multisystem inflammatory syndrome in children (MIS-C) has features that overlap with myocarditis, toxic-shock syndrome and Kawasaki disease. Current evidence indicates that MIS-C is the result of an exaggerated innate and adaptive immune response, characterized by a cytokine storm, and that it is triggered by prior SARS-CoV-2 exposure. Epidemiological, clinical and immunological differences classify MIS-C as being distinct from Kawasaki disease. Differences include the age range, and the geographical and ethnic distribution of patients. MIS-C is associated with prominent gastrointestinal and cardiovascular system involvement, admission to intensive care unit, neutrophilia, lymphopenia, high levels of IFNγ and low counts of naive CD4⁺ T cells, with a high proportion of activated memory T cells. Further investigation of MIS-C will continue to enhance our understanding of similar conditions associated with a cytokine storm.

Multisystem Inflammatory Syndrome in Children Associated with COVID-19: An Interim Review

The pediatric population is relatively less affected by novel coronavirus disease 2019 (COVID-19) compared with adults, both in numbers and severity. However, evolution of a new entity, named multisystem inflammatory syndrome in children (MIS-C), has led to significant number of children being admitted to hospital, especially to intensive care units. Case definitions of MIS-C have been defined by the World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) separately. Autoantibodies and antibody-dependent enhancement (ADE) are the key factors proposed in pathogenesis, leading to immune dysregulation, and cytokine storm. Three distinct clinical types are observed as follows: (1) fever and elevated inflammatory markers with no end-organ damage; (2) shock with severe myocardial dysfunction similar to toxic shock syndrome (TSS); and (3) with mucocutaneous features like Kawasaki's disease (KD). Cardiovascular and gastrointestinal symptoms are the predominant presentations. Inflammatory markers like C-reactive protein (CRP), ferritin, and interleukin (IL)-6 are raised along with high D-dimer and lactate dehydrogenase (LDH). Echocardiography may demonstrate low left ventricular ejection fraction (<50%) and/or coronary aneurysms. Reverse-transcription polymerase chain reaction (RT-PCR) for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) is usually negative, with most having antibodies against the virus. KD, KD shock syndrome (KDSS), and toxic shock syndrome (TSS) are the important differential diagnoses to be considered. Immunomodulatory therapy is the cornerstone of the management. Intravenous immunoglobulin (IVIg) is preferred, the next option being steroids. Supportive care, antiplatelet, and anticoagulation medications, when indicated, are also vital aspects of treatment plan. The prognosis is favorable with low mortality but meticulous cardiac monitoring and follow-up by a multidisciplinary team is very important. Being an evolving disease, future research may reveal different manifestations, newer diagnostic modalities, and better treatment options.

Serum biomarkers differentiating Kawasaki disease from febrile infections: A pilot case-control study

Although some serum biomarkers are elevated in both Kawasaki disease (KD) and infections, these conditions have not been compared by individual or combined biomarkers. The aim of this study, undertaken between January 2016 and May 2018 in a large teaching hospital, was to compare the serum concentration of cytokines, metalloproteinases (MMP) and heat shock protein (HSP) between cases defined as children with Kawasaki disease (KD) and those with febrile infections (controls). Serum concentrations of tumour necrosis factor-alpha (TNF-alpha), interleukins (IL 1beta, 6, and 8), heat shock proteins (HSP 60 and 70) and matrix metalloproteinase (MMP 9) were measured on admission in 17 children under six years of age with a temperature >38.5 °C for ≥five days, and compared between the two groups. The median age was 25 months and the median duration of fever eight days. Seven children were diagnosed with KD and ten had a febrile infection. Only the serum concentrations of IL-6 and TNF-alpha were significantly higher in the former than in the latter group (P = 0.01 and 0.04 respectively). To differentiate between the two groups with the best sensitivity and specificity, the optimal cut-off value for IL-6 was 12.6 pg/mL, and for TNF-alpha 47.9 pg/mL. Their combined increase, however, outperformed their individual concentrations. The characteristic diagnostic “signature” of the combined elevation of IL-6 and TNF-alpha serum levels has the potential, in febrile children, to differentiate early KD from febrile infections, allowing the institution of appropriate therapy.

COVID-19 and multisystem inflammatory syndrome in children and adolescents

As severe acute respiratory syndrome coronavirus 2 continues to spread worldwide, there have been increasing reports from Europe, North America, Asia, and Latin America describing children and adolescents with COVID-19-associated multisystem inflammatory conditions. However, the association between multisystem inflammatory syndrome in children and COVID-19 is still unknown. We review the epidemiology, causes, clinical features, and current treatment protocols for multisystem inflammatory syndrome in children and adolescents associated with COVID-19. We also discuss the possible underlying pathophysiological mechanisms for COVID-19-induced inflammatory processes, which can lead to organ damage in paediatric patients who are severely ill. These insights provide evidence for the need to develop a clear case definition and treatment protocol for this new condition and also shed light on future therapeutic interventions and the potential for vaccine development. TRANSLATIONS: For the French, Chinese, Arabic, Spanish and Russian translations of the abstract see Supplementary Materials section.

Gastrointestinal involvement in childhood vasculitides

AIM

The aim of this narrative review was to provide a comprehensive summary of the characteristics of gastrointestinal (GI) involvement in the most common paediatric primary vasculitides.

METHODS

We used PubMed to primarily identify papers, reviews, case series and editorials published in English from 2000 until 31 January 2020. Based on this, we report the prevalence, clinical manifestations, diagnostic approaches and management of GI involvement in each vasculitis.

RESULTS

Vasculitides are inflammatory blood vessel diseases, and the majority can affect the GI system with vascular, GI tract or solid organ involvement. GI involvement can sometimes complicate and delay the correct diagnosis. Clinical findings are usually nonspecific symptoms, such as fever, abdominal pain, nausea, vomiting and diarrhoea. Bleeding should alert paediatricians to the possibility of severe complicated vasculitis. Diagnosis relies mostly on imaging. If it goes unrecognised, GI involvement in paediatric vasculitis is a serious cause of morbidity and even mortality, related to bowel ischaemia and perforation. Treatment of GI symptoms depends on the type of vasculitis and usually involves high-dose steroids and immunosuppressants.

CONCLUSION

GI manifestations in the most common paediatric primary vasculitides were usually nonspecific, diagnosis mostly relied on imaging, and treatment usually involved high-dose corticosteroids and immunosuppressants.

Altered gut microbiota correlated with systemic inflammation in children with Kawasaki disease

Kawasaki disease (KD) is a multi-systemic vasculitis of unknown etiology that occurs mainly in children, and the disturbance of gut microbiota is generally believed to cause a hyperimmune reaction triggering KD. The aim of the study was to investigate the alterations in the fecal microbiota and assess its relationship with systemic inflammation. Totally 30 KD children were enrolled and followed up for 6 months, with another group of 30 age- and sex-matched healthy children as controls. Phylotype profiles of fecal microbial communities were analyzed using 16S rRNA gene sequencing. Serum inflammatory markers were detected by flow cytometer. We showed that KD children exhibited a significant reduction in fecal microbial diversity in the acute phase compared with the healthy controls. Enterococcus, Acinetobacter, Helicobacter, Lactococcus, Staphylococcus and Butyricimonas in acute KD children were significantly higher than the healthy children. Levels of systemic inflammation biomarkers, including IL-2, IL-4, IL-6, IL-10, TNF-α, and INF-γ, were significantly elevated in the acute KD children. Altered microbiota genera Enterococcus and Helicobacter abundances were shown to be correlated positively with IL-6, which were never previously reported in KD. This study suggested that gut microbiota alteration is closely associated with systemic inflammation, which provides a new perspective on the etiology and pathogenesis of KD.

Effects of changes on gut microbiota in children with acute Kawasaki disease

Background

Kawasaki disease (KD) is an acute febrile illness of early childhood. The exact etiology of the disease remains unknown. At present, research on KD is mostly limited to susceptibility genes, infections, and immunity. However, research on the correlation between gut microbiota and KD is rare.

Methods

Children with a diagnosis of acute KD and children undergoing physical examination during the same period were included. At the time of admission, the subjects’ peripheral venous blood and feces were collected. Faecal samples were analyzed for bacterial taxonomic content via high-throughput sequencing. The abundance, diversity, composition, and characteristic differences of the gut microbiota in KD and healthy children were compared by alpha diversity, beta diversity, linear discriminant analysis and LDA effect size analysis. Blood samples were used for routine blood examination, biochemical analysis, and immunoglobulin quantitative detection.

Results

Compared with the control group, the community richness and structure of gut microbiota in the KD group was significantly reduced (Chao1 richness estimator, mean 215.85 in KD vs. mean 725.76 in control, p < 0.01; Shannon diversity index, mean 3.32 in KD vs. mean 5.69 in control, p < 0.05). LEfSe analysis identified two strains of bacteria significantly associated with KD: Bacteroidetes and Dorea. Bacteroidetes were enriched in healthy children (mean 0.16 in KD vs. mean 0.34 in control, p < 0.05). Dorea was also enriched in healthy children but rarely existed in children with KD (mean 0.002 in KD vs. mean 0.016 in control, p < 0.05). Compared with the control, IgA and IgG in the KD group decreased (IgA, median 0.68 g/L in KD vs. median 1.06 g/L in control, p < 0.001; IgG, median 6.67 g/L in KD vs. median 9.71 g/L in control, p < 0.001), and IgE and IgM levels were not significantly changed.

Conclusions

Dysbiosis of gut microbiota occurs in children with acute KD and may be related to the etiology or pathogenesis of KD. It is worth noting that for the first time, we found that Dorea, a hydrogen-producing bacterium, was significantly reduced in children with acute KD. Overall, our results provide a theoretical basis for the prevention or diagnosis of KD based on intestinal microecology.

Our Evolving Understanding of Kawasaki Disease Pathogenesis: Role of the Gut Microbiota

Kawasaki disease (KD) was first described by Dr. Tomisaku Kawasaki in 1967. The etiology of KD has been studied comprehensively but remains largely unknown. The disease seems to result from the interplay of genetic and environmental susceptibility factors with infectious triggers, followed by a subsequent abnormal immune response characterized by increased levels of inflammatory cytokines and chemokines during the acute phase. Evidence has mounted to suggest that an imbalance between T helper 17 cells (Th17s) and regulatory T cells (Tregs) is associated with aberrant immune responses in KD. Recent advances in culture-independent techniques for detection and identification of intestinal commensal bacteria enabled the discovery that Th17 and Treg differentiation are regulated by short chain fatty acids (SCFAs), in particular butyrate, produced by the gut microbiota. This finding provided a mechanistic link between dysbiosis, defined as changes in the composition of the gut microbiota, and various inflammatory diseases. On this basis, we propose that dysbiosis, with reduced production of SCFAs leading to imbalances of Th17s/Tregs, could be involved in the etiology of KD. A pilot study supported this hypothesis, as only fecal concentrations of butyrate were significantly reduced in KD patients among SCFAs. This evolving perspective prompted us to undertake metagenomic analyses of bacterial DNA from the feces of KD patients who were antibiotic-naïve at diagnosis. Simultaneous measurements of Th17s/Tregs in peripheral blood and SCFA concentrations in feces would provide valuable information regarding the association between dysbiosis and dysregulated immune responses in KD.

Exploring Kawasaki disease-specific hub genes revealing a striking similarity of expression profile to bacterial infections using weighted gene co-expression network analysis (WGCNA) and co-expression modules identification tool (CEMiTool): An integrated bioinformatics and experimental study

Kawasaki disease (KD) has been declared a rare idiopathic condition for a long time. The children age less than five years, as the most susceptible group, are at risk of this disease. Since the cause of the disease is unknown, this study was designed to investigate the cause of KD. We applied metaDE and WGCNA packages in order to perform a meta-analysis and identify network modules of co-expressed genes, respectively, on three expression array datasets and also CEMiTool package to confirm detected modules by WGCNA. Using the Pearson correlation coefficient, the resemblance of KD to other symptomatic-similar diseases, including bacterial infections, viral infections, JIA (juvenile idiopathic arthritis), HSP (Henoch-Schönlein purpura), GAS (group A streptococcal), and HAdV (adenovirus) was accurately estimated. In addition to validation by more three expression array datasets, serum samples of 16 patients and eight control participants have undergone the Real-Time PCR assay so as to evaluate produced bioinformatic results. WGCNA showed 3840 differentially expressed genes (DEGs) in KD in comparison with other diseases accompanying resembling clinical manifestations. Through further bioinformatic analysis and validation, 42 out of DEGs were introduced as hub genes, which the results of Real-Time PCR assay subsequently attested to the majority of them. The DEGs possessed a remarkable commonality with those of bacterial conditions. According to our exhaustive results, the origin of KD has been revealed pertinent to bacterial infections. Another interesting finding in this study is introducing IVIG in combination with particular antibiotics as a novel therapeutic approach, which supported by a score of authentic research studies to overcome KD.

Kawasaki disease: pathophysiology and insights from mouse models

Kawasaki disease is an acute febrile illness and systemic vasculitis of unknown aetiology that predominantly afflicts young children, causes coronary artery aneurysms and can result in long-term cardiovascular sequelae. Kawasaki disease is the leading cause of acquired heart disease among children in the USA. Coronary artery aneurysms develop in some untreated children with Kawasaki disease, leading to ischaemic heart disease and myocardial infarction. Although intravenous immunoglobulin (IVIG) treatment reduces the risk of development of coronary artery aneurysms, some children have IVIG-resistant Kawasaki disease and are at increased risk of developing coronary artery damage. In addition, the lack of specific diagnostic tests and biomarkers for Kawasaki disease make early diagnosis and treatment challenging. The use of experimental mouse models of Kawasaki disease vasculitis has considerably improved our understanding of the pathology of the disease and helped characterize the cellular and molecular immune mechanisms contributing to cardiovascular complications, in turn leading to the development of innovative therapeutic approaches. Here, we outline the pathophysiology of Kawasaki disease and summarize and discuss the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

This Review outlines the pathophysiology of Kawasaki disease and discusses the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

Kawasaki disease is a childhood systemic vasculitis leading to the development of coronary artery aneurysms; it is the leading cause of acquired heart disease in children in developed countries.

The cause of Kawasaki disease is unknown, although it is suspected to be triggered by an unidentified infectious pathogen in genetically predisposed children.

Kawasaki disease might not be a normal immune response to an unusual environmental stimulus, but rather a genetically determined unusual and uncontrolled immune response to a common stimulus.

Although the aetiological agent in humans is unknown, mouse models of Kawasaki disease vasculitis demonstrate similar pathological features and have substantially accelerated discoveries in the field.

Genetic and transcriptomic analysis of blood samples from patients with Kawasaki disease and experimental evidence generated using mouse models have demonstrated the critical role of IL-1β in the pathogenesis of this disease and the therapeutic potential of targeting this pathway (currently under investigation in clinical trials).

Correlation of gut microbial compositions to the development of Kawasaki disease vasculitis in children

Aim: Here, we hypothesize that dysbiotic gut microbiota might contribute to the development of Kawasaki disease (KD), a pediatric disease with unknown etiology. This is the second report on gut microbiota composition in KD patients. Materials & results: 16S amplicon sequencing was performed on fecal DNA samples and revealed predominance of bacterial pathogens, such as Fusobacterium, Neisseria, Shigella and Streptococcus, in the gut of KD patients, but absent or suppressed after immunoglobulin/antibiotics therapy. In addition, beneficial bacteria propagated after the therapy. Conclusion: We conclude that prevalence of Fusobacteria, Shigella and Streptococcus might contribute to KD pathogenesis.

The microbiome in autoimmune rheumatic disease

Microbial contributions to the immunopathogenesis of autoimmune rheumatic diseases have been studied since the advent of germ theory in the 19th century. With the exception of Group A Streptococcus in rheumatic fever, early studies failed to establish causal relationships between specific pathobionts and rheumatic disease. Today, systemic autoimmune diseases are thought to result from a complex interplay of environmental factors, individual genetic risk, and stochastic events. Interactions of microbiota and the immune system have been shown to promote and sustain chronic inflammation and autoimmunity. In mechanistic studies, microbe-immune cell interactions have been implicated in the initiation of autoimmune rheumatic diseases, e.g., through the posttranslational modification of autoantigens in rheumatoid arthritis or through neutrophil cell death and cross-reactivity with commensal orthologs in systemic lupus erythematosus. In parallel, modern molecular techniques have catalyzed the study of the microbiome in systemic autoimmune diseases. Here, I review current insights gained into the skin, oral, gut, lung, and vascular microbiome in connective tissue diseases and vasculitis. Mechanism relevant to the development and propagation of autoimmunity will be discussed whenever explored. While studies on autoimmune rheumatic disease have almost invariably shown abnormal microbiome structure (dysbiosis), substantial variability in microbial composition between studies makes generalization difficult. Moreover, an etiopathogenic role of specific pathobionts cannot be inferred by association alone. Integrating descriptive studies of microbial communities with hypothesis-driven research informed by immunopathogenesis will be important in elucidating targetable mechanisms in preclinical and established rheumatic disease.

Kawasaki shock syndrome in an Arab female: case report of a rare manifestation and review of literature

BACKGROUND

Kawasaki disease shock syndrome is a relatively new and rare complication of Kawasaki disease first described in 2009.

CASE PRESENTATION

This report describes a two-year-old Arab descent female presenting with a history of high-grade fever of 2 days duration with non-specific signs of viral illness and erythematous rash. The patients' condition deteriorated rapidly requiring admission to intensive care unit. In the intensive care unit, she developed a right upper quadrant mass that was diagnosed as hydrops of the gallbladder by ultrasonography. After one dose of intravenous immunoglobulin, the patient started to recover and was transferred out of intensive care after 2 days.

CONCLUSION

Among the complications of Kawasaki disease, shock syndrome is rare and usually will have deleterious results if not diagnosed and managed promptly.

Implications of hepatic dysfunction in Kawasaki disease: Time-related changes in aspartate aminotransferase, alanine aminotransferase, total bilirubin, and C-reactive protein levels

IMPORTANCE

The cause of the hepatic dysfunction that commonly accompanies Kawasaki disease (KD) remains unclear.

OBJECTIVE

We tried to clarify the cause of the hepatic dysfunction.

METHODS

A total of 381 consecutive patients with acute KD, who had undergone inpatient treatment with intravenous immunoglobulin until the 7th day of illness, were divided into a group of 199 patients with an alanine aminotransferase (ALT) level ≥ 40 IU/L on admission (group I), a group of 52 patients with an ALT level ≥ 40 IU/L at some point after admission (group II), and a group of 130 patients with ALT levels consistently < 40 IU/L throughout hospitalization (group III). Aspartate aminotransferase (AST), ALT, total bilirubin (T-Bil), and C-reactive protein (CRP) levels were analyzed over time, and time-courses were compared.

RESULTS

In the initial stage of illness, in group I, AST, ALT, T-Bil peaked on days 1-3, and AST tended to improve significantly on the 4th day (P < 0.001). T-Bil improved on day 5 (P < 0.01), and ALT improved significantly on day 6 (P < 0.001). CRP increased every day up to day 6 (P < 0.001). In group II, AST and ALT increased after admission, and thereafter CRP increased, then decreased. The frequency of use of aspirin and aspirin doses did not differ significantly in the three groups.

INTERPRETATION

Recovery from liver dysfunction occurred in the initial stage of illness in group I-within the period of CRP exacerbation, which is an indicator of systemic inflammation.

Causes of Kawasaki Disease-From Past to Present

Kawasaki disease (KD) is a multisystem vasculitis that primarily affects the coronary arteries of young children. The causes of KD remain a mystery. It is suspected that some sort of infectious agent is involved because KD has epidemicity and seasonality. That said, the incidence of the disease is high among Japanese people, so it can be speculated that the hosts may have some sort of genetic characteristic that leaves them susceptible to KD. Various theories regarding the etiology have been asserted, such as the infectious vasculitis theory, autoantigen theory, superantigen theory, and RNA virus theory; however, none of them have been able to overcome this epidemicity. Taking into consideration the knowledge gained from previous reports, the best scenario explaining the pathogenesis is "individuals with certain genetic backgrounds are affected by microorganisms which trigger KD." In this article, the pathogenesis of KD is discussed with a focus on the microorganisms mentioned above, along with the previous and current hypotheses as well as my own opinion.

The Gut Microbiota-Host Partnership as a Potential Driver of Kawasaki Syndrome

Kawasaki syndrome (KS) is a necrotizing vasculitis of small- and medium-sized vessels mostly affecting children under 5 years of age; a host of clinical and epidemiological data supports the notion that KS might result from an infectious disease. However, many efforts have failed to identify a potentially universal trigger of KS. The contribution of the intestinal microbial community-called the "microbiota"-to KS has been evaluated by an increasing number of studies, though limited to small cohorts of patients. Differences in the microbiota composition were found in children with KS, both its acute and non-acute phase, with abnormal colonization by Streptococcus species in the intestinal tract and a wider presence of Gram-positive cocci in jejunal biopsies. In particular, a higher number of Gram-positive cocci (of the genera Streptococcus and Staphylococcus), Eubacterium, Peptostreptococcus, and HSP60-producing Gram-negative microbes have been found in the stools of KS children, and their effects on the antigenic repertoire of specific T cells and Vβ2 T cell expansion have been assessed. Conversely, Lactobacilli were lacking in most children with KS compared with other febrile illnesses and healthy controls. All studies available to date have confirmed that an imbalance in the gut microbiota might indirectly interfere with the normal function of innate and adaptive immunity, and that variable microbiota interactions with environmental factors, mainly infectious agents, might selectively drive the development of KS in genetically susceptible children. Further investigations of the intestinal microflora in larger cohorts of KS patients will provide clues to disentangle the pathogenesis of this disease and probably indicate disease-modifying agents or more rational KS-specific therapies.

Intestinal Involvement in Kawasaki Disease

OBJECTIVES

To describe a case of Kawasaki disease with intestinal involvement and to analyze other published reports to define clinical characteristics, diagnostic issues, and therapeutic approaches of gastrointestinal involvement in Kawasaki disease.

STUDY DESIGN

A computerized search without language restriction was conducted using PubMed and SCOPUS. An article was considered eligible for inclusion in the systematic review if it reported data on patient(s) with intestinal involvement in Kawasaki disease. Our case was also included in the analysis.

RESULTS

Thirty-three articles reporting 48 cases of Kawasaki disease with intestinal involvement were considered. Fever, abdominal pain, and vomiting were the most frequent symptoms observed and typical Kawasaki disease signs and symptoms appeared after intestinal complaints in all cases. Plain radiographs, ultrasonography, and computed tomography showed pseudo-obstruction as the most frequent sign of gastrointestinal involvement; 25 patients underwent surgery. Cardiac involvement was documented in 21 cases. All but three patients received medical treatment with immunoglobulin intravenous or aspirin. The outcome was good in 28 patients; 7 patients showed persistence of coronary artery abnormalities; 1 patient developed cyanosis, and later, left hand and forefoot gangrene; 3 patients died.

CONCLUSIONS

The diagnosis and treatment of Kawasaki disease might be delayed if intestinal symptoms appear before the characteristic clinical features of Kawasaki disease, thus, increasing the risk of cardiac complications. Furthermore, patients may undergo unnecessary invasive procedures. Pediatricians and pediatric surgeons, therefore, should consider Kawasaki disease among diagnoses in children with fever, abdominal symptoms, and radiologic findings of pseudo-obstruction.

Epidemiological observations of Kawasaki disease in Japan, 2013-2014

BACKGROUND

The etiology of Kawasaki disease (KD) is unknown. In Japan, the number of patients and incidence rate of KD has increased continuously since its discovery. The aim of this report was to analyze the latest nationwide epidemiological survey of KD in Japan.

METHODS

The 23rd nationwide survey of KD was conducted in 2015. To report on all patients diagnosed with KD in 2013 and 2014, a questionnaire was sent to hospitals with ≥100 beds containing pediatric departments, as well as specialized pediatric hospitals.

RESULTS

The number of KD patients reported was 15 696 in 2013 and 15 979 in 2014, resulting in an annual incidence rate of 302.5 and 308.0 per 100 000 population aged 0-4 years, respectively. The number of patients and incidence rate of KD in 2014 were the highest ever recorded in Japan. The number of patients diagnosed per month peaked in January, and a gradual increase in summer was also observed. Eight patients died of KD in 2013 and 2014.

CONCLUSIONS

The number of patients and incidence rate of KD in Japan continue to increase. Continued surveillance of epidemiological trends of KD is therefore required.

Distinct Distribution of Immunocytes in a Retropharyngeal Lymphadenopathy Associated with Kawasaki Disease: A Case Study Compared with Tonsillitis

OBJECTIVES

Retropharyngeal lesions are often associated with Kawasaki disease (KD). A 4-year-old male first presented a peritonsillar and retropharyngeal abscess-like lesion. Surgical tonsillectomy was performed to avoid a risk of mediastinal abscess, but he fulfilled the diagnostic criteria of KD after the operation. This prompted us to perform a histological study on the KD tonsils.

METHODS

The histopathology of the KD tonsil specimens were compared with hypertrophic tonsils obtained from 4 patients with chronic tonsillitis unrelated to KD assessed by the immunostainings.

RESULTS

KD tonsils showed small lymphatic follicles and neutrophil infiltration in the peritonsillar muscle layer, with no evidence of vasculitis or abscess formation. The KD tonsils exclusively showed (1) predominant activated CD4+ T cells in the perifollicular interstitium, (2) sparse scattering of CD68+ monocytes/macrophages in the lymphatic follicles, and (3) polyclonal carcinoembryonic antigen-positive cells in the lymphatic follicles and venules with the high endothelial cells.

CONCLUSIONS

The uniquely distributed immunocytes suggest the inflammatory process of KD involving the pathogen-associated molecules.

Kawasaki Disease Presenting as Acute Intestinal Obstruction

Kawasaki disease (KD) is an acute febrile illness of childhood associated with vasculitis of medium-sized arteries especially the coronary arteries. Typical clinical features involving the skin, mucous surfaces, etc., occur sequentially over a few days. We report a rare presentation of KD as a surgical abdomen in a 2-year-old boy. Awareness of this presentation is important as it can otherwise lead to a delay in starting potentially life-saving intervention like intravenous immunoglobulins for cardiac complications kept cryptic by the manifest acute abdomen.

Comprehensive pathogen detection associated with four recurrent episodes of Kawasaki disease in a patient during a single year using next-generation sequencing

Introduction:

Kawasaki disease (KD) is the most common multisystem vasculitis in childhood. Pathogens can be associated with the onset of KD. However, a lack of consistency prevails among reports about this disease.

Case presentation:

For this case of a 1-year-old boy with four recurrent episodes of KD within a year, we analysed profiles of pathogen reads in his serum and pharynx specimens using next-generation sequencing. Comparative analysis of the identified bacterial reads from serum samples found significant correlation of bacteria such as Streptococcus and Haemophilus spp. with the first and fourth episodes (R² = 0.9506) before treatment. In the first convalescent phase, the number of Streptococcus spp. was reduced remarkably (P < 0.0001). From sequencing of the pharynx specimen from the fourth episode, a similar correlation was found with serum from the fourth episode (R² = 0.6633).

Conclusion:

In this case, Streptococcus spp. may have been associated with onset of KD. Further studies must be undertaken to evaluate the putative association of micro-organism infection with KD pathogenesis.

Characterization of the gut microbiota of Kawasaki disease patients by metagenomic analysis

Kawasaki disease (KD) is an acute febrile illness of early childhood. Previous reports have suggested that genetic disease susceptibility factors, together with a triggering infectious agent, could be involved in KD pathogenesis; however, the precise etiology of this disease remains unknown. Additionally, previous culture-based studies have suggested a possible role of intestinal microbiota in KD pathogenesis. In this study, we performed metagenomic analysis to comprehensively assess the longitudinal variation in the intestinal microbiota of 28 KD patients. Several notable bacterial genera were commonly extracted during the acute phase, whereas a relative increase in the number of Ruminococcus bacteria was observed during the non-acute phase of KD. The metagenomic analysis results based on bacterial species classification suggested that the number of sequencing reads with similarity to five Streptococcus spp. (S. pneumonia, pseudopneumoniae, oralis, gordonii, and sanguinis), in addition to patient-derived Streptococcus isolates, markedly increased during the acute phase in most patients. Streptococci include a variety of pathogenic bacteria and probiotic bacteria that promote human health; therefore, this further species discrimination could comprehensively illuminate the KD-associated microbiota. The findings of this study suggest that KD-related Streptococci might be involved in the pathogenesis of this disease.

Spontaneous duodenal perforation as a complication of kawasaki disease

Kawasaki disease is generally known as a systemic vasculitis that often concerns doctors due to its serious cardiac complications; however, other visceral organs may get involved as well. Surgical manifestations of the intestinal tract in Kawasaki disease are rare. In this report, we describe the case of a 2.5-year-old boy with typical Kawasaki disease who presented with GI bleeding and surgical abdomen. The diagnosis of duodenal perforation was confirmed.

[A review of Kawasaki disease, a perspective from the articles published in Mexico since January 1977 to May 2012]

Kawasaki disease was described in 1967 by Tomisu Kawasaki. It affects children aged between one and 5 years, and it evolves with fever and small vessel vasculitis, which leads to cardiovascular complications, including coronary aneurisms, myocarditis, valve injuries, pericardial effusion and myocardial infarction; eventually involving many others organs. The etiology actually is not well known, as the exactly pathogenic mechanisms; however, now there are important advances. If the clinical signs and symptoms are identify early and the children received treatment with aspirin and intravenous immunoglobulin, the patients evolves without sequels. The Kawasaki disease is an infrequent disease in Mexico.

Kawasaki shock syndrome complicating a recurrence of Kawasaki disease

We describe a case of recurrent Kawasaki disease (KD) in a non-Asian 6-year-old boy who had been diagnosed with typical KD without cardiac involvement at age 3 years. He was admitted to the PICU 3 years later for heart failure, hypotension, and deterioration of his general condition. Ultrasonography revealed left ventricular dysfunction with a 44% ejection fraction and grade I mitral valve failure without coronary artery involvement. Subsequent observation of hyperemic conjunctiva, bilateral cervical adenopathies with erythematous skin (normal neck ultrasound and computed axial tomography findings), peeling of the fingertips at day 8 of the illness, and occurrence of an inflammatory syndrome led to a diagnosis of incomplete recurrent KD with a clinical picture of Kawasaki shock syndrome (KSS). Clinical improvement was rapidly obtained after intravenous immunoglobulin and intravenous corticosteroid therapy (30 mg/kg per day for 3 subsequent days). Left ventricular function gradually improved, with ultrasound returning to normal after 3 months. Diagnosis was difficult to establish because of the recurrence of the disease and the incomplete clinical picture, with clinical features of KSS. Physicians need to be aware of these pitfalls in the management of patients with clinical signs of KD.

Persistent endothelial damage after intravenous immunoglobulin therapy in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology. Although endothelial cell damage associated with vasculitis might lead to the hypercoagulability that is involved in coronary artery disease, the changes in coagulation after intravenous immunoglobulin therapy (IVIG) have not been well investigated in KD. The aims of this study were to address the changes in coagulation before and after IVIG in KD, and to further elucidate the coagulation-inflammation axis, with special attention to endothelial damage.

METHODS

We retrospectively collected the laboratory data before and after IVIG in 26 pediatric KD patients treated at the Nara Prefecture Western Medical Center between May 2010 and April 2012. Prothrombin time (PT), activated partial thromboplastin time (APTT) and levels of fibrin/fibrinogen degradation products (FDP) and D-dimer were assessed as coagulation markers. Fibrinogen, ferritin, serum amyloid A, procalcitonin and urine β2 microglobulin were assessed as inflammation markers. Thrombomodulin, antithrombin, factor VIII activity (FVIII:C), and von Willebrand factor antigen (VWF:Ag) were used to assess endothelial damage.

RESULTS

Prolonged PT and APTT before IVIG were significantly shortened after IVIG, and elevated levels of FDP and D-dimer were significantly decreased. Elevated levels of inflammation markers had decreased significantly after IVIG, but levels of FVIII:C and VWF:Ag remained high, even after IVIG.

CONCLUSIONS

Ameliorated inflammation by IVIG might improve the hypercoagulable state. Nevertheless, our results suggest that endothelial damage might be prolonged in IVIG-treated patients. Control of endothelial damage in KD is critical.

Erythema at BCG Inoculation Site in Kawasaki Disease Patients

INTRODUCTION

Kawasaki disease is an acute, self-limiting childhood systemic vasculitis with unknown etiology. Because there is no diagnostic test for Kawasaki disease, the diagnosis is based on clinical criteria. An important clinical sign that is not included in the classical clinical criteria for Kawasaki disease is a reaction at the Bacille Calmette-Guérin inoculation site that are present in about 30-50% of Kawasaki disease patients.

THE AIM

of this review was to highlight the usefulness of the inflammation at the Bacille Calmette-Guérin inoculation site for early diagnosis of Kawasaki disease, we conducted a literature review on Medline in PubMed area, Google scholar, Magiran and Scientific Information Database using the search terms "Kawasaki disease, Erythema, BCG, inoculation site, children, cardiac complications, coronary artery lesion, aneurysm, incomplete Kawasaki in 2013.

RESULTS AND DISCUSSION

A total of 15 articles had been found. Erythema at the Bacille Calmette-Guérin inoculation site was found in 49.87% of Kawasaki disease patients. Coronary artery abnormalities were found in 10.3% of cases. According to this review, BCGitis is more prevalent than cervical lymphadenopathy and rash and it can be a useful criterion in the diagnosis of incomplete Kawasaki disease in cases not fulfills the classic criteria of at least four of the five findings.

Possible involvement of infection with human coronavirus 229E, but not NL63, in Kawasaki disease

Although human coronavirus (HCoV)‐NL63 was once considered a possible causative agent of Kawasaki disease based on RT‐PCR analyses, subsequent studies could not confirm the result. In this study, this possibility was explored using serological tests. To evaluate the role of HCoV infection in patients with Kawasaki disease, immunofluorescence assays and virus neutralizing tests were performed. Paired serum samples were obtained from patients with Kawasaki disease who had not been treated with γ‐globulin. HCoV‐NL63 and two antigenically different isolates of HCoV‐229E (ATCC‐VR740 and a new isolate, Sendai‐H) were examined as controls. Immunofluorescence assays detected no difference in HCoV‐NL63 antibody positivity between the patients with Kawasaki disease and controls, whereas the rate of HCoV‐229E antibody positivity was higher in the patients with Kawasaki disease than that in controls. The neutralizing tests revealed no difference in seropositivity between the acute and recovery phases of patients with Kawasaki disease for the two HCoV‐229Es. However, the Kawasaki disease specimens obtained from patients in recovery phase displayed significantly higher positivity for Sendai‐H, but not for ATCC‐VR740, as compared to the controls. The serological test supported no involvement of HCoV‐NL63 but suggested the possible involvement of HCoV‐229E in the development of Kawasaki disease. J. Med. Virol. 86:2146–2153, 2014. © 2014 Wiley Periodicals, Inc.

Streptococcal superantigens: categorization and clinical associations

Superantigens are key virulence factors in the immunopathogenesis of invasive disease caused by group A streptococcus. These protein exotoxins have also been associated with severe group C and group G streptococcal infections. A number of novel streptococcal superantigens have recently been described with some resulting confusion in their classification. In addition to clarifying the nomenclature of streptococcal superantigens and proposing guidelines for their categorization, this review summarizes the evidence supporting their involvement in various clinical diseases including acute rheumatic fever.

Decreased portal vein flow during Kawasaki disease in a liver transplant patient

Abnormalities of liver function tests are frequently documented in patients with Kawasaki disease, but the mechanism responsible for this has not yet been established. Described herein is the case of a 1-year-10-month-old girl who underwent liver transplantation at 11 months of age. Eleven months after transplantation the patient was diagnosed with Kawasaki disease, which was associated with some portal flow reduction, and received i.v. immunoglobulin, after which fever abated with improvement of portal flow to its pre-fever level. Abnormalities of liver function tests in Kawasaki disease patients may occur as a result of inflammation of both the biliary and portal systems. There are no reports on the potential relationship between Kawasaki disease and the portal vein, and accumulation of further data is necessary to better examine this relationship.

Update on Kawasaki disease: epidemiology, aetiology and pathogenesis

Kawasaki disease is an acute systemic vasculitis predominantly affecting young children. It is due to an abnormal host response to as yet unidentified infectious trigger(s). Kawasaki disease may cause coronary artery damage, long-term cardiovascular morbidity and occasionally mortality, especially if the diagnosis is missed or timely treatment is not given. This is the first of two updates on Kawasaki disease. Here we review recent advances in epidemiology, possible aetiologies, host susceptibility and pathogenesis of this fascinating condition.

Clinical manifestations associated with Kawasaki disease shock syndrome in Mexican children

Recently, there have been increasing reports of severe forms of Kawasaki disease (KD) associated with shock that have been managed in pediatric intensive care units. It has been suggested that KD is more severe in the Hispanic population. We conducted a study to determine the frequency of Kawasaki disease shock syndrome (KDSS) in our population and compared characteristics between patients with KD without shock and patients with KDSS. Data from 214 patients with KD treated in a tertiary pediatric hospital were collected during a 12-year period. We compared clinical and laboratory features of KD patients without shock and KDSS patients. Of 214 consecutive patients with KD, 11 (5 %) met the definition for KDSS. All of these patients received fluid resuscitation, seven (64 %) required inotropic treatment, and six (54 %), ventilatory support. On admission, seven of these patients (64 %) had an incomplete presentation of the disease, whereas in the group of patients without shock, the relative frequency of an incomplete presentation was 29 %. Twenty percent (3/11) of patients with KDSS presented giant coronary aneurysms versus none of 203 KD patients without shock (p = 0.001); myocardial infarction, 27 % (3/11), versus 1 % (2/203) (p = 0.001); and intravenous immunoglobulin (IVIG) resistance, 60 % (6/11), versus 12 % (24/203). Gastrointestinal manifestations in the acute phase occurred in 91 % of KDSS patients versus 30 % patients without shock (p = 0.001).

CONCLUSION

Patients with KD presenting in shock seem to have an increase in gastrointestinal manifestations, incomplete presentation, IVIG resistance, and worse cardiac outcomes. Larger, prospective, multicentre studies should be carried out to corroborate these findings.

Pathogenic characterization of a cervical lymph node derived from a patient with Kawasaki disease

Kawasaki disease (KD) is the most common cause of multisystem vasculitis in childhood. Although cervical lymphadenitis is one of the major symptoms in KD, lymph node biopsy is rarely performed, because KD is usually diagnosed by clinical symptoms. A cervical lymph node biopsy was taken from a girl aged 1 year and 8 months who had suspected lymphoma, but she was diagnosed with KD after the biopsy. The cervical lymph node specimen was analyzed with multivirus real-time PCR that can detect >160 viruses, and unbiased direct sequencing with a next-generation DNA sequencer to detect potential pathogens in the lymph node. Histologically, focal necrosis with inflammatory cell infiltration, including neutrophils and macrophages, was observed in the marginal zone of the cervical lymph node, which was compatible with the acute phase of KD. Multivirus real-time PCR detected a low copy number of torque teno virus in the sample. Comprehensive direct sequencing of the cervical lymph node biopsy sample sequenced more than 8 million and 3 million reads from DNA and RNA samples, respectively. Bacterial genomes were detected in 0.03% and 1.79% of all reads in DNA and RNA samples, respectively. Although many reads corresponded to genomes of bacterial environmental microorganisms, Streptococcus spp. genome was detected in both DNA (77 reads) and RNA (2,925 reads) samples. Further studies are required to reveal any association of microbial or viral infection with the pathogenesis of KD.

Kawasaki disease: novel insights into etiology and genetic susceptibility

Kawasaki disease (KD) is a vasculitis of young childhood that particularly affects the coronary arteries. Molecular analysis of the oligoclonal IgA response in acute KD led to production of synthetic KD antibodies. These antibodies identify intracytoplasmic inclusion bodies in acute KD tissues. Light and electron microscopic studies indicate that the inclusion bodies are consistent with aggregates of viral proteins and RNA. Advances in molecular genetic analysis and completion of the Human Genome Project have sparked a worldwide effort to identify genes associated with KD. A polymorphism of one such gene, ITPKC, a negative regulator of T cell activation, confers susceptibility to KD in Japanese populations and increases the risk of developing coronary artery abnormalities in both Japanese and U.S. children. Identification of the etiologic agent and of genes conferring KD susceptibility are the best means of improving diagnosis and therapy and enabling prevention of this important disorder of childhood.