Kawasaki disease: pathophysiology and insights from mouse models

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.

Multiresistant Kawasaki Disease in a Young Infant with Giant Aneurysms Growing Fast

BACKGROUND

Kawasaki disease (KD) is a type of vasculitis in which giant coronary artery aneurysms (CAAs) can occur. There are no specific guidelines for managing giant CAAs that develop quickly and are at risk of rupture. Regarding cardiovascular drugs, only beta-blockers are formally recommended in the acute phase of KD.

CASE PRESENTATION

A 6-month-old male patient with multiresistant Kawasaki disease and giant CAAs that continued to enlarge after controlling systemic inflammation was examined. The patient required three doses of intravenous immunoglobulin, methylprednisolone pulses, and anakinra and infliximab to normalize systemic inflammation. Due to the rapid increment of aneurysms' dimensions and the risk of rupture, we introduced anticoagulant therapy and propranolol plus captopril, and titration doses were introduced according to a tolerated decrease in heart rate and arterial pressure. CAAs increment stabilized and slowly reduced their dimensions.

CONCLUSIONS

The authors describe an atypical case of multiresistant KD with giant rapidly increasing CAAs even after controlling systemic inflammation. The introduction of a beta-blocker and an angiotensin-converting enzyme (ACE) inhibitor was demonstrated to be useful for stabilizing giant CAAs growth and reducing the potential risk of rupture.

The role of transcription factors in the pathogenesis and therapeutic targeting of vascular diseases

Transcription factors (TFs) constitute an essential component of epigenetic regulation. They contribute to the progression of vascular diseases by regulating epigenetic gene expression in several vascular diseases. Recently, numerous regulatory mechanisms related to vascular pathology, ranging from general TFs that are continuously activated to histiocyte-specific TFs that are activated under specific circumstances, have been studied. TFs participate in the progression of vascular-related diseases by epigenetically regulating vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). The Krüppel-like family (KLF) TF family is widely recognized as the foremost regulator of vascular diseases. KLF11 prevents aneurysm progression by inhibiting the apoptosis of VSMCs and enhancing their contractile function. The presence of KLF4, another crucial member, suppresses the progression of atherosclerosis (AS) and pulmonary hypertension by attenuating the formation of VSMCs-derived foam cells, ameliorating endothelial dysfunction, and inducing vasodilatory effects. However, the mechanism underlying the regulation of the progression of vascular-related diseases by TFs has remained elusive. The present study categorized the TFs involved in vascular diseases and their regulatory mechanisms to shed light on the potential pathogenesis of vascular diseases, and provide novel insights into their diagnosis and treatment.

Immune control in Kawasaki disease knowledge mapping: a bibliometric analysis

BACKGROUND

Kawasaki disease is a systemic vascular disease with an unclear pathophysiology that primarily affects children under the age of five. Research on immune control in Kawasaki disease has been gaining attention. This study aims to apply a bibliometric analysis to examine the present and future directions of immune control in Kawasaki disease.

METHODS

By utilizing the themes "Kawasaki disease," "Kawasaki syndrome," and "immune control," the Web of Science Core Collection database was searched for publications on immune control in Kawasaki disease. This bibliometric analysis was carried out using VOSviewers, CiteSpace, and the R package "bibliometrix."

RESULTS

In total, 294 studies on immune control in Kawasaki disease were published in Web of Science Core Collection. The three most significant institutions were Chang Gung University, the University of California San Diego, and Kaohsiung Chang Gung Memorial Hospital. China, the United States, and Japan were the three most important countries. In this research field, Clinical and Experimental Immunology was the top-referred journal, while the New England Journal of Medicine was the most co-cited journal. The Web of Science Core Collection document by McCrindle BW et al. published in 2017 was the most cited reference. Additionally, the author keywords concentrated on "COVID-19," "SARS-CoV-2," and "multisystem inflammatory syndrome in children" in recent years.

CONCLUSION

The research trends and advancements in immune control in Kawasaki disease are thoroughly summarised in this bibliometric analysis, which is the first to do so. The data indicate recent research frontiers and hot directions, making it easier for researchers to study the immune control of Kawasaki disease.

Human Umbilical Cord Mesenchymal Stem Cells Repair Endothelial Injury and Dysfunction by Regulating NLRP3 to Inhibit Endothelial Cell Pyroptosis in Kawasaki Disease

Vascular endothelial inflammation and endothelial dysfunction are the main causes of endothelial injury in Kawasaki disease (KD). Human umbilical cord-derived mesenchymal stem cells (Huc-MSCs) have multiple functions in immune regulation. This study examined whether Huc-MSCs inhibited endothelial inflammation and improved endothelial function in KD through constructing cell and in vivo animal KD vasculitis models. The pyroptosis factor NOD-like receptor protein 3 (NLRP3) was involved in the inflammatory process in the acute phase of KD. After tail vein injection of Huc-MSCs, inflammatory cell infiltration and the expression of pyroptosis-related proteins in the LCWE-induced KD mouse vasculitis model were significantly reduced. In vitro, NLRP3-dependent pyroptosis successfully induced human umbilical vein endothelial cell (HUVEC) damage. Huc-MSCs effectively increased the abilities of impaired HUVECs to proliferate, migrate, invade, and form vessel-like tubes, while inhibiting their apoptosis, suggesting that Huc-MSCs can reduce inflammation and improve vascular endothelial function by inhibiting the NLRP3-dependent pyroptosis pathway in KD, providing a possibility and novel target for KD endothelial injury and dysfunction.

Identification of hub genes and pathogenesis in Kawasaki disease based on bioinformatics analysis

BACKGROUND

The aim of this study was to explore new biomarkers of Kawasaki disease (KD) and provide evidence for clinical diagnosis and treatment.

MATERIALS AND METHODS

Gene Expression Omnibus (GEO) datasets GSE68004 and GSE73461 were downloaded, and the differentially expressed genes (DGEs) were taken, along with DEGs enrichment analysis and protein interaction network. Finally, five algorithms in CytoHubba plug-in were applied to obtain hub genes.

RESULTS

In this study, 32 Co-DEGs were identified, and these genes mainly participated in neutrophil degranulation, neutrophil activation involved in immune response, and negative regulation of cytokine production involved in immune response; meanwhile, they were primarily enriched in starch and sucrose metabolism, fatty acid metabolism, autophagy and apoptosis, ferroptosis, and other pathways. Combined with the results of PPI and CytoHubba, 13 key genes were selected as follows: S100A12, HK3, HP, MMP9, MCEMP1, PYGL, ARG1, HIST2H2AA, ANXA3, HIST2H2AC, HIST2H2AA3, GYG1, DYSF.

CONCLUSIONS

These 13 key genes may mediate the occurrence and development of KD through various processes such as immune regulation, inflammatory response, glucose metabolism, autophagy, and apoptosis, which provide valuable references for the diagnosis and treatment of KD.

Inhibition of IL-1 Ameliorates Cardiac Dysfunction and Arrhythmias in a Murine Model of Kawasaki Disease

BACKGROUND

Kawasaki disease (KD) is an acute febrile illness and systemic vasculitis often associated with cardiac sequelae, including arrhythmias. Abundant evidence indicates a central role for IL (interleukin)-1 and TNFα (tumor necrosis factor-alpha) signaling in the formation of arterial lesions in KD. We aimed to investigate the mechanisms underlying the development of electrophysiological abnormalities in a murine model of KD vasculitis.

METHODS

Lactobacillus casei cell wall extract-induced KD vasculitis model was used to investigate the therapeutic efficacy of clinically relevant IL-1Ra (IL-1 receptor antagonist) and TNFα neutralization. Echocardiography, in vivo electrophysiology, whole-heart optical mapping, and imaging were performed.

RESULTS

KD vasculitis was associated with impaired ejection fraction, increased ventricular tachycardia, prolonged repolarization, and slowed conduction velocity. Since our transcriptomic analysis of human patients showed elevated levels of both IL-1β and TNFα, we asked whether either cytokine was linked to the development of myocardial dysfunction. Remarkably, only inhibition of IL-1 signaling by IL-1Ra but not TNFα neutralization was able to prevent changes in ejection fraction and arrhythmias, whereas both IL-1Ra and TNFα neutralization significantly improved vasculitis and heart vessel inflammation. The treatment of L casei cell wall extract-injected mice with IL-1Ra also restored conduction velocity and improved the organization of Cx43 (connexin 43) at the intercalated disk. In contrast, in mice with gain of function of the IL-1 signaling pathway, L casei cell wall extract induced spontaneous ventricular tachycardia and premature deaths.

CONCLUSIONS

Our results characterize the electrophysiological abnormalities associated with L casei cell wall extract-induced KD and show that IL-1Ra is more effective in preventing KD-induced myocardial dysfunction and arrhythmias than anti-TNFα therapy. These findings support the advancement of clinical trials using IL-1Ra in patients with KD.

A bibliometric analysis of Kawasaki disease from 1974 to 2022

Objective

To analyse the research history, development trends and current status of relevant literature in the field of Kawasaki disease, and to provide the basis for future directions in Kawasaki disease (KD) research.

Methods

Literature on Kawasaki disease published between January 1974 and December 2022 was searched for in the Web of Science database, and CiteSpace was used to perform visual analyses.

Results

The search yielded a total of 6950 articles. The number of publications related to Kawasaki disease showed an increasing trend. A collaborative network analysis revealed that the United States, Japan and mainland China were the most influential countries in this field. The University of California system contributed the most publications and the journal with the most publications was Circulation. JW Newburger was an authoritative author in this field. "Coronary artery lesion", "Intravenous immunoglobulin" (IVIG) and "Risk factor" were three prominent keywords. Keyword bursts changed from "TNF" and "IVIG", which focused on aetiology and treatment, to "Long term management", which emphasized the recovery period, and to "Kawasaki-like disease" and "Multisystem inflammatory syndrome" during the novel coronavirus pandemic. Trends of highly cited references indicated that landmark articles in different periods focused on Kawasaki disease guidelines, gene polymorphisms and multisystem inflammatory syndrome caused by the novel coronavirus.

Conclusion

The aetiology of Kawasaki disease remains unclear, but viral infection is likely to play an important role. The combination of evolving sequencing technologies, large-scale epidemiological investigations and prospective cohort studies is likely to be important in exploring Kawasaki disease and improving its prognosis in future.

Association between long-term PM2.5 exposure and risk of Kawasaki disease in children: A nationwide longitudinal cohort study

BACKGROUND

Based on previous studies suggesting air pollution as a potential risk factor for Kawasaki Disease (KD), we examined the association of long-term exposure to childhood fine particulate matter (PM2.5) with the risk of KD.

METHODS

We used National Health Insurance Service-National Sample Cohort data from 2002 to 2019, which included beneficiaries aged 0 years at enrollment and followed-up until the onset of KD or age 5 years. The onset of KD was defined as the first hospital visit record with a primary diagnostic code of M30.3, based on the 10th revision of the International Classification of Diseases, and with an intravenous immunoglobulin (IVIG) prescription. We assigned PM2.5 concentrations to 226 districts, based on mean annual predictions from a machine learning-based ensemble prediction model. We performed Cox proportional-hazards modeling with time-varying exposures and confounders.

RESULTS

We identified 134,634 individuals aged five or less at enrollment and, of these, 1220 individuals who had a KD onset and an IVIG prescription during study period. The average annual concentration of PM2.5 exposed to the entire cohort was 28.2 μg/m³ (Standard Deviation 2.9). For each 5 μg/m³ increase in annual PM2.5 concentration, the hazard ratio of KD was 1.21 (95% CI 1.05-1.39).

CONCLUSIONS

In this nationwide, population-based, cohort study, long-term childhood exposure to PM2.5 was associated with an increased incidence of KD in children. The study highlights plausible mechanisms for the association between PM2.5 and KD, but further studies are needed to confirm our findings.

Development of a prediction model for progression of coronary artery lesions in Kawasaki disease

BACKGROUNDS

This study aimed to identify risk factors for the progression of coronary artery lesions (CALs) in children with Kawasaki disease (KD) and to develop a nomogram prediction model.

METHODS

This is a retrospective case-control study in which the participants were categorized into three groups based on the changes of the maximum Z score (Zmax) of coronary arteries at the 1-month follow-up compared with the baseline Zmax: CALs-progressed, CALs-improved, and CALs-unchanged.

RESULTS

Of total 387 patients, 65 (27%), 319 (73%), and 3 (0.7%) patients were categorized into CALs-progressed group, CALs-improved group, and CALs-unchanged group, respectively. Six independent factors associated with CALs progression were identified, including initial IVIG resistance, baseline Zmax, the number of coronary arteries involved, C-reactive protein, albumin, and soluble interleukin-2 receptor (odds ratio: 7.19, 1.51, 2.32, 1.52, 0.86, and 1.46, respectively; all P-values < 0.01). The nomogram prediction model including these six independent risk factors yielded an area under the curve (AUC) of 0.80 (95% confidence interval, 0.74 to 0.86). The accuracy of this model reached 81.7% after the Monte-Carlo Bootstrapping 1000 repetitions.

CONCLUSIONS

The nomogram prediction model can identify children at high risk for the progression of CALs at early stages.

IMPACT

Six independent factors associated with CALs progression were identified, including initial IVIG resistance, baseline Zmax, the number of coronary arteries involved, CRP, ALB, and sIL-2R. The prediction model we constructed can identify children at high risk for the progression of CALs at early stages and help clinicians make individualized treatment plans. Prospective, multi-centered studies with larger sample sizes are warranted to validate the power of this prediction model in children with KD.

Immunopathology of and potential therapeutics for secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome: a translational perspective

Secondary hemophagocytic lymphohistiocytosis/macrophage activation syndrome (sHLH/MAS) is a life-threatening immune disorder triggered by rheumatic disease, infections, malignancies, or medications. Characterized by the presence of hemophagocytic macrophages and a fulminant cytokine storm, sHLH/MAS leads to hyperferritinemia and multiorgan failure and rapidly progresses to death. The high mortality rate and the lack of specific treatments necessitate the development of a new drug. However, the complex and largely unknown immunopathologic mechanisms of sHLH/MAS, which involve dysfunction of various immune cells, diverse etiologies, and different clinical contexts make this effort challenging. This review introduces the terminology, diagnosis, and clinical features of sHLH/MAS. From a translational perspective, this review focuses on the immunopathological mechanisms linked to various etiologies, emphasizing potential drug targets, including key molecules and signaling pathways. We also discuss immunomodulatory biologics, existing drugs under clinical evaluation, and novel therapies in clinical trials. This systematic review aims to provide insights and highlight opportunities for the development of novel sHLH/MAS therapeutics.

Markers of Endothelial Dysfunction in Kawasaki Disease: An Update

Kawasaki disease (KD) is a medium vessel vasculitis that has a special predilection for coronary arteries. Cardiovascular complications include the development of coronary artery abnormalities (CAAs) and myocarditis. Endothelial dysfunction (ED) is now recognized to be a key component in the pathogenesis of KD and is believed to contribute to the development of CAAs. ED has been evaluated by several clinical parameters. However, there is paucity of literature on laboratory markers for ED in KD. The evaluation of ED can be aided by the identification of biomarkers such as oxidative stress markers, circulating cells and their progenitors, angiogenesis factors, cytokines, chemokines, cell-adhesion molecules, and adipokines. If validated in multicentric studies, these biomarkers may be useful for monitoring the disease course of KD. They may also provide a useful predictive marker for the development of premature atherosclerosis that is often a concern during long-term follow-up of KD. This review provides insights into the current understanding of the significance of ED in KD.

Positive Echocardiographic Association between Carotid Artery and Coronary Artery Diameter and Z-Score in a Mouse Model of Kawasaki Disease

Kawasaki disease (KD) occurs in young children, has an unknown etiology, and can cause such life-threatening complications as coronary artery aneurysm. A mouse model using Lactobacillus casei cell wall extract (LCWE) with intraperitoneal injection was established for KD years ago. Histological examination of coronary artery lesions indicated features similar to those of vascular lesions of patients with KD. Since animals must be sacrificed during histological examination, the longitudinal survey of coronary artery lesions (CALs) is difficult. The aim of this study was to survey the vasculitis status of the coronary artery and the carotid artery in a KD mouse model.

METHOD

LCWE was intraperitoneally injected into 5-week-old male C57BL/6 mice to induce CALs. We studied the longitudinal status of the carotid and coronary arteries and analyzed the Z-score of coronary artery diameter.

RESULTS

Carotid artery wall thickness (day 7) and diameter (day 14) significantly increased in the LCWE group with a dose-dependent effect (p < 0.05). Aortic diameter and wall thickness demonstrated significant increases on day 28 and day 7, respectively (p < 0.05). Carotid artery outer diameter and wall thickness were positively associated with coronary artery diameter on day 28 (p < 0.01). Coronary artery diameter significantly increased in the LCWE group after day 7 (p < 0.05). The percentage of Z > 3.0 indicated was more than 80% in the high-dose LCWE group and 0% in the control group.

CONCLUSIONS

This report is the first to use coronary artery Z-score in a mouse model of KD by echocardiography and to find a positive association between carotid artery and coronary artery diameter.

Atypical Cat Scratch Disease With Splenic Lesion Mimicking Kawasaki Disease in a Healthy 5-Year-old Girl

BACKGROUND

Atypical cat scratch disease (CSD) and Kawasaki disease (KD) are differential diagnoses of pediatric febrile illnesses. Diagnosing atypical CSD can be challenging because of its wide range of symptoms. However, its similarity to KD has rarely been addressed.

METHODS

We present the case of a 5-year-old girl with atypical CSD and splenic lesions who fulfilled the diagnostic criteria for KD. We also conducted a literature review of previous cases in which CSD was suspected alongside KD and detailed the diagnosis and treatment processes.

RESULTS

A previously healthy 5-year-old girl with prolonged fever and symptoms resembling those of KD was admitted to our hospital. There was no evidence of an abnormal coronary artery, and her condition did not improve after the initial treatment for KD and bacterial infection. A history of contact with cats and multiple granulomatous lesions in the spleen on abdominal ultrasonography led to a clinical diagnosis of atypical CSD. Trimethoprim-sulfamethoxazole treatment resulted in symptom resolution. Elevated serum Bartonella henselae IgG and IgM antibodies confirmed the diagnosis of CSD. In this case, we avoided second-line treatment for KD with an alternative CSD diagnosis. Additionally, we identified 4 documented cases of CSD presenting with KD-like features in the literature. Intravenous immunoglobulin was ineffective in all cases, including the present case.

CONCLUSIONS

In cases of atypical CSD where KD is suspected, actively seeking organ-specific symptoms may facilitate an early clinical diagnosis of CSD. Adopting this approach could yield multiple advantages, including reduced invasiveness for the patient and decreased healthcare-related expenditures.

Clinical manifestations and outcomes associated with PICU admission in children with multisystem inflammatory syndrome in Taiwan: A retrospective cohort study

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a rare and serious systemic inflammatory disorder that occurs following a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aims to investigate the clinical manifestations, risk factors associated with pediatric intensive care unit (PICU) admission, and outcome among children with MIS-C in Taiwan.

METHODS

A retrospective analysis was conducted among pediatric patients diagnosed with MIS-C between June 2022 and February 2023 at Chang Gung Memorial Hospital, Linkou, Taiwan. Data on demographics, clinical features, laboratory findings, treatment modalities, and outcomes were collected and analyzed.

RESULTS

Twenty-eight MIS-C patients, including 9 boys and 19 girls, with an average age of 5.3 ± 3.8 years old, were enrolled. Most of the cases (78.6%) were diagnosed following the first pandemic wave of COVID-19 in Taiwan. The leading clinical manifestations observed were fever (100%), skin rash (64.3%), tachycardia (46.4%), and vomiting (46.4%). Nine patients (32.1%) were admitted to the PICU due to hypotension or neurological manifestations. Higher levels of band-form white blood cells, procalcitonin, ferritin, d-dimer, prothrombin time, NT-proBNP, and lower platelet levels on arrival were associated with PICU admission (p = 3.9 × 10-2 ,9 × 10-3 , 4 × 10-3 ,1 × 10-3 , 5 × 10-3 , 4.1 × 10-2 , and 3.4 × 10-2 , respectively). Arrhythmia in one case (3.5%) and coronary artery abnormalities, including dilatation in two cases (7.1%) and small aneurysms in one case (3.5%) were identified. Regardless of ICU admission, no patients experienced systolic dysfunction or mortality following treatment.

CONCLUSION

MIS-C cases in Taiwan have a favorable outcome. Although one-third of the patients required PICU admission, none of the MIS-C cases resulted in severe cardiovascular morbidity or mortality. This study provides valuable insights into the clinical manifestations and outcomes associated with PICU admission in children with MIS-C in Taiwan.

The association between prenatal per-and polyfluoroalkyl substance levels and Kawasaki disease among children of up to 4 years of age: A prospective birth cohort of the Japan Environment and Children's study

Kawasaki disease (KD) is common among pediatric patients and is associated with an increased risk of later cardiovascular complications, though the precise pathophysiology of KD remains unknown. Per- and polyfluoroalkyl substances (PFAS) have gathered notoriety as the causal pathogens of numerous diseases as well as for their immunosuppressive effects. The present epidemiological study aims to assess whether PFAS may affect KD risk. We evaluated research participants included in the ongoing prospective nationwide birth cohort of the Japan Environment and Children's Study (JECS). Among the over 100,000 pregnant women enrolled in the JECS study, 28 types of PFAS were measured in pregnancy in a subset of participants (N = 25,040). The JECS followed their children born between 2011 and 2014 (n total infants = 25,256; n Kawasaki disease infants = 271), up to age four. Among the 28 types of PFAS, those which were detected in >60 % of participants at levels above the method reporting limit (MRL) were eligible for analyses. Multivariable logistic regressions were implemented on the seven eligible PFAS, adjusting for multiple comparison effects. Finally, we conducted Weighted Quantile Sum (WQS) and Bayesian kernel machine regression (BKMR) to assess the effects of the PFAS mixture on KD. Therefore, we ran the BKMR model using kernel mechanical regression equations to examine PFAS exposure and the outcomes of KD. Upon analysis, the adjusted multivariable regression results did not reach statistical significance for the seven eligible substances on KD, while odds ratios were all under 1.0. WQS regression was used to estimate the mixture effect of the seven eligible PFAS, revealing a negative correlation with KD incidence; similarly, BKMR implied an inverse association between the PFAS mixture effect and KD incidence. In conclusion, PFAS exposure was not associated with increased KD incidence.

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.

[Role and mechanisms of CHI3L1 in coronary artery lesions in a mouse model of Kawasaki disease-like vasculitis]

OBJECTIVES

To explore the role and potential mechanisms of chitinase-3-like protein 1 (CHI3L1) in coronary artery lesions in a mouse model of Kawasaki disease (KD)-like vasculitis.

METHODS

Four-week-old male SPF-grade C57BL/6 mice were randomly divided into a control group and a model group, with 10 mice in each group. The model group mice were intraperitoneally injected with 0.5 mL of lactobacillus casei cell wall extract (LCWE) to establish a mouse model of KD-like vasculitis, while the control group mice were injected with an equal volume of normal saline. The general conditions of the mice were observed on the 3rd, 7th, and 14th day after injection. Changes in coronary artery tissue pathology were observed using hematoxylin-eosin staining. The level of CHI3L1 in mouse serum was measured by enzyme-linked immunosorbent assay. Immunofluorescence staining was used to detect the expression and localization of CHI3L1, von Willebrand factor (vWF), and α-smooth muscle actin (α-SMA) in coronary artery tissue. Western blot analysis was used to detect the expression of CHI3L1, vWF, vascular endothelial cadherin (VE cadherin), Caspase-3, B cell lymphoma-2 (Bcl-2), Bcl-2 associated X protein (Bax), nuclear factor κB (NF-κB), and phosphorylated NF-κB (p-NF-κB) in coronary artery tissue.

RESULTS

The serum level of CHI3L1 in the model group was significantly higher than that in the control group (P<0.05). Compared to the control group, the expression of CHI3L1 in the coronary artery tissue was higher, while the expression of vWF was lower in the model group. The relative expression levels of CHI3L1, Bax, Caspase-3, NF-κB, and p-NF-κB were significantly higher in the model group than in the control group (P<0.05). The relative expression levels of vWF, VE cadherin, and Bcl-2 were lower in the model group than in the control group (P<0.05).

CONCLUSIONS

In the LCWE-induced mouse model of KD-like vasculitis, the expression levels of CHI3L1 in serum and coronary arteries increase, and it may play a role in coronary artery lesions through endothelial cell apoptosis mediated by inflammatory reactions.

Aortitis after administration of pegfilgrastim to a healthy donor for peripheral blood stem cell collection

A 45-year-old man who was a sibling donor for allogeneic peripheral blood stem cell transplantation (allo-PBSCT) was administered 7.2 mg of pegfilgrastim for stem cell collection. Peripheral blood stem cells were collected 4 days after administration of pegfilgrastim (Day 4) and 4.32 × 106 /kg of CD34-positive cells per recipient body weight were obtained. Fever of 38 ℃ or higher and left submandibular pain appeared on Day 6. Ultrasonography and contrast-enhanced computed tomography (CT) showed wall thickening of the carotid artery and the abdominal aorta. We carefully excluded the possibilities of cardiovascular and autoimmune diseases by thorough examination, and ultimately diagnosed pegfilgrastim-induced aortitis. The patient's fever resolved rapidly after treatment with prednisolone (PSL) 1 mg/kg. We began to taper PSL after eight days. Sixty-one days after starting PSL, we confirmed that abdominal aortic wall thickening had improved by contrast-enhanced CT. We continued to taper off PSL and stopped 141 days later with no relapse thereafter. This is the first case report of pegfilgrastim-induced aortitis in an allo-PBSCT donor. Careful monitoring is warranted when administering pegfilgrastim to donors even without past medical history.

[18F]FDG PET-MR characterization of aortitis in the IL1rn-/- mouse model of giant-cell arteritis

BACKGROUND

Metabolic imaging is routinely used to demonstrate aortitis in patients with giant-cell arteritis. We aimed to investigate the preclinical model of aortitis in BALB/c IL1rn-/- mice using [18F]fluorodeoxyglucose ([18F]FDG) positron emission tomography-magnetic resonance (PET-MR), gamma counting and immunostaining. We used 15 first-generation specific and opportunistic pathogen-free (SOPF) 9-week-old IL1rn-/- mice, 15 wild-type BALB/cAnN mice and 5 s-generation specific pathogen-free (SPF) 9-week-old IL1rn-/-. Aortic [18F]FDG uptake was assessed as the target-to-background ratio (TBR) using time-of-flight MR angiography as vascular landmarks.

RESULTS

[18F]FDG uptake measured by PET or gamma counting was similar in the first-generation SOPF IL1rn-/- mice and the wild-type group (p > 0.05). However, the first-generation IL1rn-/- mice exhibited more interleukin-1β (p = 0.021)- and interleukin-6 (p = 0.019)-positive cells within the abdominal aorta than the wild-type mice. In addition, the second-generation SPF group exhibited significantly higher TBR (p = 0.0068) than the wild-type mice on the descending thoracic aorta, unlike the first-generation SOPF IL1rn-/- mice.

CONCLUSIONS

In addition to the involvement of interleukin-1β and -6 in IL1rn-/- mouse aortitis, this study seems to validate [18F]FDG PET-MR as a useful tool for noninvasive monitoring of aortitis in this preclinical model.

Rising Kawasaki disease incidence in New Zealand: analysis of national population incidence and outcomes 2000-2017

OBJECTIVE

The recent epidemiology of Kawasaki disease (KD) in New Zealand (NZ) is unknown. Our aim was to describe the incidence, seasonal variation, long-term outcomes and mortality for KD in NZ.

DESIGN

Retrospective national database analysis.

SETTING

New Zealand.

PATIENTS

First hospitalisation and deaths diagnosed with KD.

MAIN OUTCOME MEASURES

Data were extracted for all hospital admissions in NZ coded as KD (International Classification of Diseases (ICD)-9 and ICD-10) from the National Minimum Dataset 1 January 2000 to 31 December 2017. Age, sex, ethnicity and associated diagnoses were available to review. Intervention rates for immunoglobulin administration were also analysed.

RESULTS

Over the study period, there were 1008 children with initial hospitalisation for KD. The mean age was 39.8 months (SD 37) and 592 (59%) were boys. The annual incidence rate of KD has increased from 12.2 to 19.5 per 100 000 children <5 years old (0.46 case increase per year; 95% CI 0.09 to 0.83). Children of Asian and Pacific Island ethnicities had the highest incidence (51.2 and 26.1/100 000, respectively). The highest growth in incidence was among East Asian children. The case mortality rate was low (12 of 1008, 1.2%); however, Māori were over-represented (6 of 12 deaths).

CONCLUSIONS

There is evidence of increasing KD hospitalisation in NZ, similar to recent studies from Northeast Asia and Australia. KD incidence data were available for retrospective review from a national database, but data on complications and outcomes were incomplete. Notification for KD and an active national surveillance system are recommended to improve care. Future work should focus on factors contributing to poorer outcomes in Māori.

Dysbiosis of the gut microbiota as a susceptibility factor for Kawasaki disease

Introduction

Gut microbial imbalance (dysbiosis) has been reported in patients with acute Kawasaki disease (KD). However, no studies have analyzed the gut microbiota while focusing on susceptibility to KD. This study aimed to evaluate whether dysbiosis elevates susceptibility to KD by assessing children with a history of KD.

Methods

Fecal DNA was extracted from 26 children with a history of KD approximately 1 year prior (KD group, 12 boys; median age, 32.5 months; median time from onset, 11.5 months) and 57 age-matched healthy controls (HC group, 35 boys; median age, 36.0 months). 16S rRNA gene analysis was conducted with the Illumina Miseq instrument. Sequence reads were analyzed using QIIME2.

Results

For alpha diversity, Faith's phylogenetic diversity was significantly higher in the KD group. Regarding beta diversity, the two groups formed significantly different clusters based on Bray-Curtis dissimilarity. Comparing microbial composition at the genus level, the KD and HC groups were significantly different in the abundance of two genera with abundance over 1% after Benjamini-Hochberg false discovery rate correction for multiple comparisons. Compared with the HC group, the KD group had higher relative abundance of Ruminococcus gnavus group and lower relative abundance of Blautia.

Discussion and conclusion

Ruminococcus gnavus group reportedly includes pro-inflammatory bacteria. In contrast, Blautia suppresses inflammation via butyrate production. In the predictive functional analysis, the proportion of gut microbiota involved in several pathways was lower in the KD group. Therefore, dysbiosis characterized by distinct microbial diversity and decreased abundance of Blautia in parallel with increased abundance of Ruminococcus gnavus group might be a susceptibility factor for KD.

PTX3 promotes IVIG resistance-induced endothelial injury in Kawasaki disease by regulating the NF-κB pathway

Intravenous immunoglobulin (IVIG) resistance leads to serious complications in Kawasaki disease (KD) with no effective treatment. This study aimed to investigate the effects of pentraxin 3 (PTX3) on human coronary artery endothelial cells (HCAECs). PTX3 levels were measured using quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assay, and western blotting. Cell viability was detected using the MTT assay. Biological functions were analyzed using CCK-8, EdU, flow cytometry, TUNEL, and qRT-PCR. The levels of factors of the NF-κB pathway were examined using western blotting. The results demonstrated that PTX3 expression was highest in patients and HCAECs with IVIG-resistance. Knockdown of PTX3 promoted proliferation and suppressed apoptosis and inflammation of IVIG-resistant HCAECs, whereas PTX3 overexpression produced the opposite results. Moreover, PTX3 activated the NF-κB pathway in IVIG-resistant HCAECs. A rescue study showed that PTX3 modulated biological behaviors by regulating the NF-κB pathway. Overall, our findings demonstrate that PTX3 promotes IVIG resistance-induced endothelial injury by activating the NF-κB pathway, suggesting that PTX3 may become a novel therapeutic target for patients with IVIG-resistant KD.

Serum amyloid A as a biomarker for immunoglobulin resistance in Kawasaki disease

BACKGROUND

Intravenous immunoglobulin (IVIG) resistance is of prime importance in Kawasaki disease (KD). In this study, we examined the value and mechanism of serum amyloid A (SAA) level in predicting IVIG resistance in patients with KD.

METHODS

SAA levels were measured in 497 consecutive patients with KD before IVIG therapy in the training set. The patients were divided into two groups (IVIG-responsive and IVIG-resistant) according to the American Heart Association (AHA) definition of IVIG resistance. Demographic, echocardiographic, and laboratory data were also retrospectively analyzed and tabulated to predict IVIG resistance. The predictive value of SAA was validated on test sets of prospective data. Cytokine microarrays were analyzed from 4 patients with resistant to IVIG, 4 patients with responsive to IVIG and 4 healthy volunteers.

RESULTS

During the training set, 409 patients with KD were enrolled, of whom 43 (10.5%) were resistant to initial IVIG treatment and 47 (11.49%) had coronary artery lesions (CALs). Serum levels of SAA were higher in the IVIG resistant group compared to the IVIG responsive group, (380.00 [204.40-547.25] vs 230.85 [105.40-490.00] mg/L; p = .008). The values of total bilirubin, C-reactive protein, neutrophils, alanine aminotransferase, aspartate aminotransferase, interleukin-6(IL-6), and procalcitonin were significantly higher in the IVIG-resistant group than in the IVIG-responsive group (p < .05); however, the lymphocytes, platelets, serum sodium levels, and duration of fever before IVIG therapy were significantly lower (p < .05). There was no significant difference in SAA levels between patients with KD with and without CALs. Binary logistic regression analysis showed that SAA (p = .008), neutrophils (p < .001), total bilirubin (p = .001), platelet count (p = .004), and serum sodium level (p = .019) were independent factors influencing IVIG resistance. The optimal cutoff value of SAA for IVIG resistance prediction was 252.45 mg/L, with a corresponding clinical sensitivity of 69.8% and specificity of 54.4%. Based on receiver operating characteristic (ROC) curve analyses, the area under the curve (AUC) of combined detection with these five indicators was 0.800, clinical sensitivity was 69.8%, and specificity was 76.2%. In the prospective data, the sensitivity, specificity, and accuracy of SAA for identifying IVIG resistance KD were 77.8%,69.0%, and 70.0%, respectively. Compared with IVIG- responsive group and healthy children, the levels of IL-6 was upregulated significantly in IVIG-resistant group through cytokine microarrays.

CONCLUSIONS

SAA may be a potential biomarker for predicting IVIG responsiveness to KD, Combined detection of SAA levels, total bilirubin, neutrophil count, platelet count, and serum sodium levels is superior to that of any other single indicator for predicting IVIG resistance in KD. And elevated SAA may accompany with IL-6 in KD patients, its use in clinical practice may be helpful for treatment management.

Roles of Oxidative Injury and Nitric Oxide System Derangements in Kawasaki Disease Pathogenesis: A Systematic Review

Kawasaki disease (KD) is an acute febrile vasculitis that occurs mostly in children younger than five years. KD involves multiple intricately connected inflammatory reactions activated by a cytokine cascade. Despite therapeutic advances, coronary artery damage may develop in some patients, who will be at risk of clinical cardiovascular events and even sudden death. The etiology of KD remains unclear; however, it may involve both genetic and environmental factors leading to aberrant inflammatory responses. Given the young age of onset, prenatal or perinatal exposure may be etiologically relevant. Multisystem inflammatory syndrome in children, a post-infectious hyper-inflammatory disorder associated with severe acute respiratory syndrome coronavirus 2, has features that overlap with those of KD. Available evidence indicates that vascular endothelial dysfunction is a critical step in the sequence of events leading to the development of cardiovascular lesions in KD. Oxidative stress and the dysregulation of the nitric oxide (NO) system contribute to the pathogenesis of inflammatory responses related to this disease. This review provides current evidence and concepts highlighting the adverse effects of oxidative injury and NO system derangements on the initiation and progression of KD and potential therapeutic strategies for cardiovascular pathologies in affected children.

Cardiac involvement in children with paediatric multisystem inflammatory syndrome temporally associated with SARS-CoV-2 (PIMS-TS): data from a prospective nationwide surveillance study

BACKGROUND

Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) may occur 4 to 8 weeks after SARS-CoV-2 infection. The acute presentation of PIMS-TS has been well described, but data on longer-term outcomes, particularly cardiac, is scarce.

METHODS

This prospective nationwide surveillance study included children and adolescents less than 18 years of age who were hospitalised with PIMS-TS in Switzerland between March 2020 and March 2022. Data was collected from all 29 paediatric hospitals through the Swiss Paediatric Surveillance Unit (SPSU) during hospitalisation and approximately six weeks after discharge. The data was analysed after categorising the participants into three groups based on their admission status to the intensive care unit (ICU) (non-ICU, ICU-moderate) and the requirement for invasive ventilatory and/or inotropic support (ICU-severe).

RESULTS

Overall, 204 children were included of whom 194 (95.1%) had follow-up data recorded. Median age was 9.0 years (interquartile range [IQR] 6.0-11.5) and 142 (69.6%) were male. In total, 105/204 (51.5%) required ICU admission, of whom 55/105 (52.4%) received inotropic support and 14/105 (13.3%) mechanical ventilation (ICU-severe group). Echocardiography was performed in 201/204 (98.5%) children; 132 (64.7%) had a cardiac abnormality including left ventricular systolic dysfunction (73 [36.3%]), a coronary artery abnormality (45 [22.4%]), pericardial effusion (50 [24.9%]) and mitral valve regurgitation (60 [29.9%]). Left ventricular systolic dysfunction was present at admission in 62/201 (30.8%) children and appeared during hospitalisation in 11 (5.5%) children. A coronary artery abnormality was detected at admission in 29/201 (14.2%) children and developed during hospitalisation or at follow-up in 13 (6.5%) and 3 (1.5%) children, respectively. None of the children had left ventricular systolic dysfunction at follow-up, but a coronary abnormality and pericardial effusion were found in 12 (6.6%) and 3 (1.7%) children, respectively. School absenteeism at the time of follow-up was more frequent in children who had been admitted to the ICU (2.5% in the non-ICU group compared to 10.4% and 17.6% in the ICU-moderate and ICU-severe group, respectively) (p = 0.011).

CONCLUSION

Cardiac complications in children presenting with PIMS-TS are common and may worsen during the hospitalisation. Irrespective of initial severity, resolution of left ventricular systolic dysfunction is observed, often occurring rapidly during the hospitalisation. Most of the coronary artery abnormalities regress; however, some are still present at follow-up, emphasising the need for prolonged cardiac evaluation after PIMS-TS.

Profiling humoral responses to COVID-19 immunization in Kawasaki disease using SARS-CoV-2 variant protein microarrays

Kawasaki disease (KD) is a form of acute systemic vasculitis syndrome that predominantly occurs in children under the age of 5 years. Its etiology has been postulated due to not only genetic factors but also the presence of foreign antigens or infectious agents. To evaluate possible associations between Kawasaki disease (KD) and COVID-19, we investigated humoral responses of KD patients against S-protein variants with SARS-CoV-2 variant protein microarrays. In this study, plasma from a cohort of KD (N = 90) and non-KD control (non-KD) (N = 69) subjects in categories of unvaccinated-uninfected (pre-pandemic), SARS-CoV-2 infected (10-100 days after infection), and 1-dose, 2-dose, and 3-dose BNT162b2 vaccinated (10-100 days after vaccination) was collected. The principal outcomes were non-KD-KD differences for each category in terms of anti-human/anti-His for binding antibodies and neutralizing percentage for surrogate neutralizing antibodies. Binding antibodies against spikes were lower in the KD subjects with 1-dose of BNT162b2, and mean differences were significant for the P.1 S-protein (non-KD-KD, 3401; 95% CI, 289.0 to 6512; P = 0.0252), B.1.617.2 S-protein (non-KD-KD, 4652; 95% CI, 215.8 to 9087; P = 0.0351) and B.1.617.3 S-protein (non-KD-KD, 4874; 95% CI, 31.41 to 9716; P = 0.0477). Neutralizing antibodies against spikes were higher in the KD subjects with 1-dose of BNT162b2, and mean percentage differences were significant for the 1-dose BNT162b2 B.1.617.3 S-protein (non-KD-KD, -22.89%; 95% CI, -45.08 to -0.6965; P = 0.0399), B.1.1.529 S-protein (non-KD-KD, -25.96%; 95% CI, -50.53 to -1.376; P = 0.0333), BA.2.12.1 S-protein (non-KD-KD, -27.83%; 95% CI, -52.55 to -3.115; P = 0.0195), BA.4 S-protein (non-KD-KD, -28.47%; 95% CI, -53.59 to -3.342; P = 0.0184), and BA.5 S-protein (non-KD-KD, -30.42%; 95% CI, -54.98 to -5.869; P = 0.0077). In conclusion, we have found that KD patients have a comparable immunization response to healthy individuals to SARS-CoV-2 infection and COVID-19 immunization.

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.

Pathophysiological and clinical point of view on Kawasaki disease and MIS-C

This article compares two important pathophysiological states, Kawasaki disease, and multisystem inflammatory syndrome, in children associated with COVID-19 (MIS-C). Both occur predominantly in children, have a temporal association with an infectious agent, and are associated with immune-system alteration and systemic inflammation under certain circumstances. The two share common pathophysiology, including enhancement of interleukin-1 neutrophils, activation of the inflammasome, pyroptosis, or NETosis. Moreover, the clinical presentation of the diseases overlaps. However, they are indeed two separate diseases, proven by the differences in the epidemiological and etiological aspects and the pathophysiological processes involved in the development and frequency of some clinical signs. This article highlights potentially exciting areas that have not yet been studied in detail, which could help better understand the development of these diseases.

Novel role for linear ubiquitination in regulating NFAT1 stability

Linear ubiquitination is an important post-translational modification regulating the activation of numerous proinflammatory signalling mediators. Deregulated linear ubiquitination has been implicated in the pathogenesis of several inflammatory and autoimmune diseases. In this issue, Miao et al. have identified a novel role for linear ubiquitination in the stabilisation of the NFAT1 transcription factor, leading to enhanced NFAT1-mediated gene expression, which might have functional implications in patients with Kawasaki disease.

Extracellular Matrix Remodeling in Vascular Disease: Defining Its Regulators and Pathological Influence

Because of structural and cellular differences (ie, degrees of matrix abundance and cross-linking, mural cell density, and adventitia), large and medium-sized vessels, in comparison to capillaries, react in a unique manner to stimuli that induce vascular disease. A stereotypical vascular injury response is ECM (extracellular matrix) remodeling that occurs particularly in larger vessels in response to injurious stimuli, such as elevated angiotensin II, hyperlipidemia, hyperglycemia, genetic deficiencies, inflammatory cell infiltration, or exposure to proinflammatory mediators. Even with substantial and prolonged vascular damage, large- and medium-sized arteries, persist, but become modified by (1) changes in vascular wall cellularity; (2) modifications in the differentiation status of endothelial cells, vascular smooth muscle cells, or adventitial stem cells (each can become activated); (3) infiltration of the vascular wall by various leukocyte types; (4) increased exposure to critical growth factors and proinflammatory mediators; and (5) marked changes in the vascular ECM, that remodels from a homeostatic, prodifferentiation ECM environment to matrices that instead promote tissue reparative responses. This latter ECM presents previously hidden matricryptic sites that bind integrins to signal vascular cells and infiltrating leukocytes (in coordination with other mediators) to proliferate, invade, secrete ECM-degrading proteinases, and deposit injury-induced matrices (predisposing to vessel wall fibrosis). In contrast, in response to similar stimuli, capillaries can undergo regression responses (rarefaction). In summary, we have described the molecular events controlling ECM remodeling in major vascular diseases as well as the differential responses of arteries versus capillaries to key mediators inducing vascular injury.

Epstein-Barr virus downregulates the α7 nicotinic acetylcholine receptor of CD8+ T lymphocytes might associate with coronary artery lesions in Kawasaki disease patients

OBJECTIVES

Kawasaki disease (KD) is a systemic vasculitis that is caused by immunological dysregulation in children exposed to pathogens like Epstein-Barr virus (EBV). Myocardial ischemia or infarction due to coronary artery lesions (CALs) might be lethal. However, it is unclear how pathogens, immunomodulation, and CALs interact, particularly in KD patients co-infected with the most widespread virus, EBV.

METHODS

We investigated pathogen carriage and fundamental clinical data in 281 KD patients. Immunological differences between CALs and non-CALs in KD patients under different conditions were analyzed. Then, the effect of infection by different pathogens on the immune response was excluded, and most EBV co-infected KD patients were included to assess the incidence of CALs, the level of immune modulation, and regulatory mechanisms in different EBV infection states.

RESULTS

Our results showed multiple pathogenic infections occur in KD patients, with EBV being the most prevalent. The incidence of CALs in the EBV-DNA (+) acute infection group, EBV-DNA (-) acute infection group, and EBV latent infection group was 0 (0/6), 27.27% (3/11) and 41.67% (10/24), respectively. The two groups were younger and had increased IL-6 levels and B cells, decreasing CD8+ T cells than the EBV-DNA (+) acute infection group. Interestingly, the increased B cells were not associated with immunoglobulin release. Additionally, these patients down-regulated α7 nicotinic acetylcholine receptor (α7nAChR) and downstream molecule PI3K/AKT/mTOR while activating the NF-κB.

CONCLUSION

Patients with different EBV infection statuses exhibit different incidences of CALs. In acute EBV-DNA (-) infected and latent EBV-infected patients, the number of CD8+ T cells decreased and downregulated CD8+ T cells' α7nAChR and PI3K/AKT/mTOR, which may associate with CALs, while the expression of NF-κB and the pro-inflammatory factor IL-6 was upregulated by inhibiting the anti-inflammatory molecule α7nAChR.

Maternal Obesity and Kawasaki Disease-like Vasculitis: A New Perspective on Cardiovascular Injury and Inflammatory Response in Offspring Male Mice

Maternal obesity affects the risk of cardiovascular disease and inflammatory response in offspring. However, the impact of maternal obesity on offspring with Kawasaki disease (KD), the leading cause of childhood acquired heart disease, is still an understudied area. This study aimed to elucidate the impact of maternal obesity on offspring in KD-like vasculitis and the underlying mechanisms. Offspring of obese female mice and normal diet dams were randomly divided into two subgroups. The pups were injected intraperitoneally with either Candida albicans water-soluble fraction (CAWS) or phosphate buffered saline (PBS) to establish the obesity (OB)-CAWS group, OB group, wild type (WT)-CAWS group, and WT group. Their weight was monitored during the study. After four weeks, echocardiography was applied to obtain the alternation of cardiac structures. Mouse cytokine panel, Hematoxylin-Eosin (HE) staining, western blot, and real-time qPCR were used to study the pathological changes and protein and RNA expression alternations. Based on the study of pathology, serology and molecular biology, maternal obesity lead to more severe vasculitis and induced altered cardiac structure in the offspring mice and promoted the expression of pro-inflammatory cytokines through activating the NF-κB signaling pathway. Maternal obesity aggravated the inflammatory response of offspring mice in KD-like vasculitis.

The use of neutrophil-lymphocyte ratio for the prediction of refractory disease and coronary artery lesions in patients with Kawasaki disease

BACKGROUND

Kawasaki disease is a vasculitis that can lead to cardiac complications, including coronary artery disease and cardiogenic shock. Various scoring systems have been developed to determine those that will be refractory to routine intravenous immunoglobulin therapy or develop coronary artery disease. The objective of this study was to determine if the neutrophil-lymphocyte ratio could predict refractory disease and coronary artery lesions in patients with Kawasaki disease.

METHODS

A systematic review of the literature was performed to identify manuscripts describing comparisons of neutrophil-lymphocyte ratio between those who had refractory disease and those who did not, and between those who developed coronary artery lesions and those who did not. Mean difference was compared between groups. Areas under the curve were utilised to determine the pooled area under the curve.

RESULTS

12 studies with 5593 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of refractory disease. Neutrophil-lymphocyte ratio before therapy was higher in refractory disease with a mean difference of 2.55 (p < 0.01) and pooled area under the curve of 0.724. Neutrophil-lymphocyte ratio after therapy was higher in refractory disease with a mean difference of 1.42 (p < 0.01) and pooled area under the curve for of 0.803. Five studies with 1690 patients were included in the final analyses of neutrophil-lymphocyte ratio for the prediction of coronary artery lesions. Neutrophil-lymphocyte ratio before therapy was higher in coronary artery lesions with a mean difference of 0.65 (p < 0.01).

CONCLUSION

The use of neutrophil-lymphocyte ratio may help physicians in the identification of patients at risk of refractory disease and coronary artery lesions in patients with Kawasaki disease.

Concomitant Kawasaki Disease and Rotavirus Infection-More Than Just a Coincidence: A Case Report

The definitive role of viral infections, such as rotavirus, in causing Kawasaki disease (KD) remains uncertain. However, the intriguing observation of concomitant rotavirus infection and KD suggests a potential association. This study aimed to investigate this relationship. We reported a case of concomitant KD and rotavirus infection complicated by hyponatraemia and anasarca. For the systematic review, we used three large databases, namely PubMed, Ovid, and Scopus, to search articles with the terms "Kawasaki" and "rotavirus". We also used Google Scholar as our secondary source. We included articles that fulfilled the following criteria: (i) articles reporting on children aged 18 and below; (ii) articles reporting on patients infected with rotavirus prior to or concomitant with KD; and (iii) articles written in English only. Three articles were included and analysed in combination with our reported patient. All patients exhibited gastrointestinal symptoms, including diarrhoea and vomiting, in addition to non-resolving fevers, which eventually manifested more signs and symptoms to support the diagnosis of KD. Stool samples from all patients revealed positive rotavirus antigens. Two patients (n = 2) were noted to have hyponatraemia and hypoalbuminaemia. Three (n = 3) manifested coronary artery abnormalities (CAA). Even though the relationship is not fully understood yet, it is known that the combination of these two pathologies can cause catastrophic immune responses and complications.

Platelets exacerbate cardiovascular inflammation in a murine model of Kawasaki disease vasculitis

Kawasaki disease (KD) is the leading cause of acquired heart disease among children. Increased platelet counts and activation are observed during the course of KD, and elevated platelet counts are associated with higher risks of developing intravenous immunoglobulin resistance and coronary artery aneurysms. However, the role of platelets in KD pathogenesis remains unclear. Here, we analyzed transcriptomics data generated from the whole blood of patients with KD and discovered changes in the expression of platelet-related genes during acute KD. In the Lactobacillus casei cell wall extract (LCWE) murine model of KD vasculitis, LCWE injection increased platelet counts and the formation of monocyte-platelet aggregates (MPAs), upregulated the concentration of soluble P-selectin, and increased circulating thrombopoietin and interleukin 6 (IL-6). Furthermore, platelet counts correlated with the severity of cardiovascular inflammation. Genetic depletion of platelets (Mpl-/- mice) or treatment with an anti-CD42b antibody significantly reduced LCWE-induced cardiovascular lesions. Furthermore, in the mouse model, platelets promoted vascular inflammation via the formation of MPAs, which likely amplified IL-1B production. Altogether, our results indicate that platelet activation exacerbates the development of cardiovascular lesions in a murine model of KD vasculitis. These findings enhance our understanding of KD vasculitis pathogenesis and highlight MPAs, which are known to enhance IL-1B production, as a potential therapeutic target for this disorder.

French national diagnostic and care protocol for Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis with a particular tropism for the coronary arteries. KD mainly affects male children between 6 months and 5 years of age. The diagnosis is clinical, based on the international American Heart Association criteria. It should be systematically considered in children with a fever, either of 5 days or more, or of 3 days if all other criteria are present. It is important to note that most children present with marked irritability and may have digestive signs. Although the biological inflammatory response is not specific, it is of great value for the diagnosis. Because of the difficulty of recognising incomplete or atypical forms of KD, and the need for urgent treatment, the child should be referred to a paediatric hospital as soon as the diagnosis is suspected. In the event of signs of heart failure (pallor, tachycardia, polypnea, sweating, hepatomegaly, unstable blood pressure), medical transfer to an intensive care unit (ICU) is essential. The standard treatment is an infusion of IVIG combined with aspirin (before 10 days of fever, and for a minimum of 6 weeks), which reduces the risk of coronary aneurysms. In case of coronary involvement, antiplatelet therapy can be maintained for life. In case of a giant aneurysm, anticoagulant treatment is added to the antiplatelet agent. The prognosis of KD is generally good and most children recover without sequelae. The prognosis in children with initial coronary involvement depends on the progression of the cardiac anomalies, which are monitored during careful specialised cardiological follow-up.

The reduced SCFA-producing gut microbes are involved in the inflammatory activation in Kawasaki disease

Kawasaki disease (KD), an acute febrile systemic vasculitis in children, has become the leading cause of acquired heart disease in developed countries. Recently, the altered gut microbiota was found in KD patients during the acute phase. However, little is known about its characteristics and role in the pathogenesis of KD. In our study, an altered gut microbiota composition featured by the reduction in SCFAs-producing bacteria was demonstrated in the KD mouse model. Next, probiotic Clostridium butyricum (C. butyricum) and antibiotic cocktails were respectively employed to modulate gut microbiota. The use of C. butyricum significantly increased the abundance of SCFAs-producing bacteria and attenuated the coronary lesions with reduced inflammatory markers IL-1β and IL-6, but antibiotics depleting gut bacteria oppositely deteriorated the inflammation response. The gut leakage induced by dysbiosis to deteriorate the host's inflammation was confirmed by the decreased intestinal barrier proteins Claudin-1, Jam-1, Occludin, and ZO-1, and increased plasma D-lactate level in KD mice. Mechanistically, SCFAs, the major beneficial metabolites of gut microbes to maintain the intestinal barrier integrity and inhibit inflammation, was also found decreased, especially butyrate, acetate and propionate, in KD mice by gas chromatography-mass spectrometry (GC-MS). Moreover, the reduced expression of SCFAs transporters, monocarboxylate transporter 1 (MCT-1) and sodium-dependent monocarboxylate transporter 1 (SMCT-1), was also shown in KD mice by western blot and RT-qPCR analyses. As expected, the decrease of fecal SCFAs production and barrier dysfunction were improved by oral C. butyricum treatment but was deteriorated by antibiotics. In vitro, butyrate, not acetate or propionate, increased the expression of phosphatase MKP-1 to dephosphorylate activated JNK, ERK1/2 and p38 MAPK against excessive inflammation in RAW264.7 macrophages. It suggests a new insight into probiotics and their metabolites supplements to treat KD.

Kawasaki disease: ubiquitin-specific protease 5 promotes endothelial inflammation via TNFα-mediated signaling

BACKGROUND

This study aimed to explore the functions of ubiquitin-specific protease 5 (USP5) in the endothelial inflammation of Kawasaki disease (KD).

METHODS

USP5 expression levels in HCAECs were examined after stimulation with TNFα or KD sera. The inflammatory cytokine expression level and nuclear factor κB (NF-κB) signaling activation proteins were also investigated in HCAECs by using USP5 overexpression/knockdown lentivirus as well as its small molecule inhibitor vialinin A.

RESULTS

USP5 expression level is upregulated in HCAECs after stimulation with KD sera. Similarly, the USP5 expression level is also increased in a time- and dose-dependent manner upon TNFα stimulation in HCAECs. Moreover, USP5 sustains proinflammatory cytokine production and NF-κB signaling activation, whereas USP5 knockdown causes the proinflammatory cytokine levels to decrease and suppress NF-κB signaling activation. Notably, the USP5 inhibitor vialinin A can suppress the expression of inflammatory genes induced by TNFα and IL-1β in HCAECs.

CONCLUSIONS

Our study identified USP5 as a positive regulator of TNFα production and its downstream signaling activation during the inflammatory responses in HCAECs, and demonstrated that its inhibitor vialinin A might serve as a candidate drug for KD therapy to prevent the excessive production of proinflammatory cytokines.

IMPACT

USP5 is upregulated in human coronary artery endothelial cells (HCAECs) whether incubated with acute KD sera or TNFα in vitro. USP5 promotes proinflammatory cytokine expression by sustaining NF-κB signaling activation in HCAECs. The USP5 inhibitor vialinin A can suppress the expression levels of proinflammatory cytokines in HCAEC, thus providing a novel mechanism and intervention strategy in KD therapy.

Plasma interleukin-41 serves as a potential diagnostic biomarker for Kawasaki disease

INTRODUCTION

Kawasaki disease (KD) is a systemic vasculitis that causes abnormalities in the coronary arteries. Interleukin (IL)-41 is a novel immunoregulatory cytokine involved in the pathogenesis of some inflammatory and immune-related diseases. However, the role of IL-41 in KD is unclear. The purpose of this study was to detect the expression of IL-41 in the plasma of children with KD and its relationship with the disease.

METHODS

A total of 44 children with KD and 37 healthy controls (HC) were recruited for this study. Plasma concentrations of IL-41 were determined by ELISA. Correlations between plasma IL-41 levels and KD-related clinical parameters were analyzed by Pearson correlation and multivariate linear regression analysis. Receiver operating characteristic curve analysis was used to assess the clinical value of IL-41 in the diagnosis of KD.

RESULTS

Our results showed that plasma IL-41 levels were significantly elevated in children with KD compared with HC. Correlation analysis demonstrated that IL-41 levels were positively correlated with D-dimer and N-terminal pro-B-type natriuretic peptide, and negatively correlated with IgM, mean corpuscular hemoglobin concentration, total protein, albumin and pre-albumin. Multivariable linear regression analysis revealed that IgM and mean corpuscular hemoglobin concentrations were associated with IL-41. Receiver operating characteristic curve analysis showed that the area under the curve of IL-41 was 0.7101, with IL-41 providing 88.64 % sensitivity and 54.05 % specificity.

CONCLUSION

Our study indicated that plasma IL-41 levels in children with KD were significantly higher than those in HC, and may provide a potential diagnostic biomarker for KD.

CD169 expression on monocytes as a marker for assessing type I interferon status in pediatric inflammatory diseases

BACKGROUND

Evaluation of type I interferons (IFNs) in inflammatory or autoimmune diseases is challenging because of their rapid clearance in peripheral blood. The IFN gene expression signature has recently been used to evaluate the IFN status; however, this is often a labor-intensive and time-consuming procedure. Therefore, we assessed the feasibility of measuring expression of an IFN-inducible protein, CD169 (Siglec-1), on monocytes and circulating levels of soluble CD169 as alternative markers for type I IFN status in various pediatric inflammatory diseases.

METHODS

Data from flow cytometric analysis of surface CD169 on monocytes and an enzyme-linked immunosorbent assay of soluble CD169 in peripheral blood were compared with serum IFN-α levels in 8 patients with viral infections, 5 with bacterial infections, 10 with systemic lupus erythematosus (SLE), 5 with Kikuchi-Fujimoto disease (KFD), 7 with Kawasaki disease (KD), and 8 with inflammatory bowel disease (IBD), and in 8 healthy controls.

RESULTS

Surface CD169 expression was detected mainly on CD14⁺ monocytes and was significantly increased in patients with viral infections, SLE, and KFD, but not in patients with bacterial infections, KD, and IBD. There were similar trends for circulating soluble CD169; however, there was a significant increase only in patients with viral infections. Surface CD169 levels were significantly correlated with serum levels of IFN-α and soluble CD169.

CONCLUSION

Analysis of CD169 expression on CD14⁺ monocytes may be useful for rapid assessment of type I IFN status for differentiation of pediatric inflammatory diseases from type 1 IFN-mediated diseases.

Identification of Hub Biomarkers and Immune and Inflammation Pathways Contributing to Kawasaki Disease Progression with RT-qPCR Verification

Background. Kawasaki disease (KD) is characterized by a disordered inflammation response of unknown etiology. Immune cells are closely associated with its onset, although the immune-related genes’ expression and possibly involved immune regulatory mechanisms are little known. This study aims to identify KD-implicated significant immune- and inflammation-related biomarkers and pathways and their association with immune cell infiltration. Patients and Methods. Gene microarray data were collected from the Gene Expression Omnibus database. Differential expression analysis, weighted gene coexpression network analysis (WGCNA), least absolute shrinkage and selection operator (LASSO) regression, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and gene set enrichment analysis (GSEA) were used to find KD hub markers. GSEA was used to assess the infiltration by 28 immune cell types and their connections to essential gene markers. Receiver operating characteristic (ROC) curves were used to examine hub markers’ diagnostic effectiveness. Finally, hub genes’ expressions were validated in Chinese KD patients by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Results. One hundred and fifty-one unique genes were found. Among 10 coexpression modules at WGCNA, one hub module exhibited the strongest association with KD. Thirty-six overlapping genes were identified. Six hub genes were potential biomarkers according to LASSO analysis. Immune infiltration revealed connections among activated and effector memory CD4+ T cells, neutrophils, activated dendritic cells, and macrophages. The six hub genes’ diagnostic value was shown by ROC curve analysis. Hub genes were enriched in immunological and inflammatory pathways. RT-qPCR verification results of FCGR1B ( $P<0.001$ ), GPR84 ( $P<0.001$ ), KREMEN1 ( $P<0.001$ ), LRG1 ( $P<0.001$ ), and TDRD9 ( $P<0.001$ ) upregulated expression in Chinese KD patients are consistent with our database analysis. Conclusion. Neutrophils, macrophages, and activated dendritic cells are strongly linked to KD pathophysiology. Through immune-related signaling pathways, hub genes such as FCGR1B, GPR84, KREMEN1, LRG1, and TDRD9 may be implicated in KD advancement.

Neurological involvement, immune response, and biomarkers in Kawasaki disease along with its pathogenesis, therapeutic and diagnostic updates

Kawasaki disease is an acute, febrile disease that is not typically fatal if treated and affects infants and children more commonly. More than 80% of the afflicted patients are under the age of four. This disease most commonly affects coronary arteries. In a minority of cases, Aneurysms can burst or produce thrombosis, and they can cause infarction. The distinctive redness in the palms and soles of the feet might result from a delayed-type hypersensitivity reaction to a cross-reactive or recently discovered antigen (s). Autoantibodies against epithelial cells and smooth muscle cells are produced as a result of subsequent macromolecule synthesis and polyclonal white blood cell activation, which intensifies the redness. Kawasaki disease's clinical manifestations range from oral skin disease to the blistering of the mucosa, symptoms involving the hands and the feet, skin disease of the palms and soles, a desquamative rash, and cervical lymphatic tissue enlargement (so it is also referred to as tissue layer lymphatic tissue syndrome). Most untreated patients develop some vessel sequelae, from well-organized coronary inflammation to severe arterial blood vessel dilatation to giant artery aneurysms with rupture or occlusion, infarction, and thrombosis. With human gamma globulin administration, reasonable standards of medical care, and the use of analgesics, the speed of symptomatic progression and inflammatory artery changes are reduced. In this review, we have covered the immunology of Kawasaki disease, its biomarkers, and the neurological manifestations of this multisystem illness. We have also included a discussion on its pathogenesis, diagnosis, and treatment.

Protective Roles of Xijiao Dihuang Tang on Coronary Artery Injury in Kawasaki Disease

PURPOSE

Xijiao Dihuang Tang (XJDHT) is a classical formula of traditional Chinese medicine constituted of Cornu Bubali, Rehmannia glutinosa (Gaertn.) DC., Paeonia lactiflora Pall., and Paeonia suffruticosa Andrews. It was first mentioned in the medical classic "Beiji Qianjin Yaofang" written by Simiao Sun in Tang Dynasty. It shows very strong antipyretic and anticoagulant effects and has been clinically applied to treat various type of blood loss, purple and black spots, heat stroke, and glossitis. Kawasaki disease (KD) is considered as a kind of acute febrile illness in children with systemic vasculitis as the main lesions. The aim of this research is to clarify whether XJDHT can play a protective role in KD.

METHODS

A mouse model of Candida albicans water-soluble fraction (CAWS)-induced coronary arteritis and a KD cell model with tumor necrosis factor (TNF)-α induction were employed to investigate the potential effect and mechanism of XJDHT on coronary artery injury in KD.

RESULTS

Data showed that XJDHT remarkably alleviated the coronary artery injury of KD mice, as evidenced by reduced inflammation and downregulated expression of pro-inflammatory cytokines interleukin (IL)-1β and TNF-α. In vitro investigation showed that XJDHT could promote cell proliferation, inhibit cell apoptosis, and improve mitochondrial functions. Subsequent studies demonstrated that XJDHT rescued endothelial cell injury by PI3K/Akt-NFκB signaling pathway. Component analysis of XJDHT detected thirty-eight chemically active ingredients, including paeoniflorin, albiflorin, and paeoniflorigenone, which in in vitro experiments exhibited significant rescue effects on TNF-α-mediated endothelial cell injury.

CONCLUSION

Our findings demonstrated that XJDHT mitigated coronary artery injury of KD through suppressing endothelial cell damage via PI3K/Akt-NFκB signaling.

The protective roles of liraglutide on Kawasaki disease via AMPK/mTOR/NF-κB pathway

Kawasaki disease (KD) is an acute febrile rash illness among children of unknown etiology, with coronary artery injury. The main purpose of this study was to investigate the protective effects of liraglutide on KD, and elucidate the underlying mechanisms. The candida albicans water-soluble fraction (CAWS)-induced coronary arteritis of mouse KD model in vivo and tumor necrosis factor α (TNF-α) induced endothelial cell injury of human umbilical vein endothelial cell (HUVEC) model in vitro were used to explore the anti-inflammation and anti-apoptosis effects of liraglutide on KD. In vivo results showed that liraglutide could significantly alleviate the coronary artery injury of KD mice, as evidenced by the reduction of inflammatory infiltration around the coronary arteries, downregulation of inflammatory cytokines and chemokines expressions, and decrease of TUNEL (Terminal deoxynucleotidyl transferase dUTP nick end labeling) positive cell rates. The results in vitro also displayed that liraglutide could markedly relieve the inflammatory of TNF-α induced HUVECs through downregulating the expressions of inflammatory and chemokine indicators as well as inhibit TNF-α induced HUVEC apoptosis by the less ratio of apoptotic cells, the more loss of mitochondrial membrane potential (△Ψm), the lower level of intracellular reactive oxygen species (ROS), and the more ratio of BCL-2/BAX. Further in vivo and in vitro studies demonstrated that liraglutide could rescue endothelial cell injury through AMPK/mTOR/NF-κB pathway. In conclusion, liraglutide could play protective roles on KD through inhibiting endothelial cell inflammation and apoptosis via the activation of AMPK/mTOR/NF-κB pathway.

Neurological involvement, immune response, and biomarkers in Kawasaki disease along with its pathogenesis, therapeutic and diagnostic updates

Kawasaki disease is an acute, febrile disease that is not typically fatal if treated and affects infants and children more commonly. More than 80% of the afflicted patients are under the age of four. This disease most commonly affects coronary arteries. In a minority of cases, Aneurysms can burst or produce thrombosis, and they can cause infarction. The distinctive redness in the palms and soles of the feet might result from a delayed-type hypersensitivity reaction to a cross-reactive or recently discovered antigen (s). Autoantibodies against epithelial cells and smooth muscle cells are produced as a result of subsequent macromolecule synthesis and polyclonal white blood cell activation, which intensifies the redness. Kawasaki disease's clinical manifestations range from oral skin disease to the blistering of the mucosa, symptoms involving the hands and the feet, skin disease of the palms and soles, a desquamative rash, and cervical lymphatic tissue enlargement (so it is also referred to as tissue layer lymphatic tissue syndrome). Most untreated patients develop some vessel sequelae, from well-organized coronary inflammation to severe arterial blood vessel dilatation to giant artery aneurysms with rupture or occlusion, infarction, and thrombosis. With human gamma globulin administration, reasonable standards of medical care, and the use of analgesics, the speed of symptomatic progression and inflammatory artery changes are reduced. In this review, we have covered the immunology of Kawasaki disease, its biomarkers, and the neurological manifestations of this multisystem illness. We have also included a discussion on its pathogenesis, diagnosis, and treatment.

Platelet activation and mitophagy induction by thymic stromal lymphopoietin (TSLP) is associated with thrombosis in Kawasaki disease

Kawasaki disease (KD) is an acute vasculitis of early childhood with unknown cause, which can be complicated by coronary artery lesions resulting in thrombosis. Fu and coworkers identify thymic stromal lymphopoietin (TSLP) to be increased in KD patients with thrombosis. They demonstrate that TSLP can activate platelets, induce mitophagy and trigger thrombus formation in vitro, suggesting that TSLP may have potential as a therapeutic target against KD-associated thrombosis. Commentary on: Fu L, et al. TSLP induces platelet mitophagy and promotes thrombosis in Kawasaki disease. Br J Haematol. 2023; 200:776-791.

Single cell RNA-seq resolution revealed CCR1+/SELL+/XAF+ CD14 monocytes mediated vascular endothelial cell injuries in Kawasaki disease and COVID-19

INTRODUCTION

The COVID-19 pandemic provide the opportunities to explore the numerous similarities in clinical symptoms with Kawasaki disease (KD), including severe vasculitis. Despite this, the underlying mechanisms of vascular injury in both KD and COVID-19 remain elusive. To identify these mechanisms, this study employs single-cell RNA sequencing to explore the molecular mechanisms of immune responses in vasculitis, and validate the results through in vitro experiments.

METHOD

The single-cell RNA sequencing (scRNA-seq) analysis of peripheral blood mononuclear cells (PBMCs) was carried out to investigate the molecular mechanisms of immune responses in vasculitis in KD and COVID-19. The analysis was performed on PBMCs from six children diagnosed with complete KD, three age-matched KD healthy controls (KHC), six COVID-19 patients (COV), three influenza patients (FLU), and four healthy controls (CHC). The results from the scRNA-seq analysis were validated through flow cytometry and immunofluorescence experiments on additional human samples. Subsequently, monocyte adhesion assays, immunofluorescence, and quantitative polymerase chain reaction (qPCR) were used to analyze the damages to endothelial cells post-interaction with monocytes in HUVEC and THP1 cultures.

RESULTS

The scRNA-seq analysis revealed the potential cellular types involved and the alterations in genetic transcriptions in the inflammatory responses. The findings indicated that while the immune cell compositions had been altered in KD and COV patients, and the ratio of CD14+ monocytes were both elevated in KD and COV. While the CD14+ monocytes share a large scale of same differentiated expressed geens between KD and COV. The differential activation of CD14 and CD16 monocytes was found to respond to both endothelial and epithelial dysfunctions. Furthermore, SELL+/CCR1+/XAF1+ CD14 monocytes were seen to enhance the adhesion and damage to endothelial cells. The results also showed that different types of B cells were involved in both KD and COV, while only the activation of T cells was recorded in KD.

CONCLUSION

In conclusion, our study demonstrated the role of the innate immune response in the regulation of endothelial dysfunction in both KD and COVID-19. Additionally, our findings indicate that the adaptive immunity activation differs between KD and COVID-19. Our results demonstrate that monocytes in COVID-19 exhibit adhesion to both endothelial cells and alveolar epithelial cells, thus providing insight into the mechanisms and shared phenotypes between KD and COVID-19.

Potential roles of NLRP3 inflammasome in the pathogenesis of Kawasaki disease

There is a heterogeneous group of rare illnesses that fall into the vasculitis category and are characterized mostly by blood vessel inflammation. Ischemia and disrupted blood flow will cause harm to the organs whose blood arteries become inflamed. Kawasaki disease (KD) is the most prevalent kind of vasculitis in children aged 5 years or younger. Because KD's cardiovascular problems might persist into adulthood, it is no longer thought of as a self-limiting disease. KD is a systemic vasculitis with unknown initiating factors. Numerous factors, such as genetic predisposition and infectious pathogens, are implicated in the etiology of KD. As endothelial cell damage and inflammation can lead to coronary endothelial dysfunction in KD, some studies hypothesized the crucial role of pyroptosis in the pathogenesis of KD. Additionally, pyroptosis-related proteins like caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), proinflammatory cytokines like IL-1 and IL-18, lactic dehydrogenase, and Gasdermin D (GSDMD) have been found to be overexpressed in KD patients when compared to healthy controls. These occurrences may point to an involvement of inflammasomes and pyroptotic cell death in the etiology of KD and suggest potential treatment targets. Based on these shreds of evidence, in this review, we aim to focus on one of the well-defined inflammasomes, NLRP3, and its role in the pathophysiology of KD.