Search

Nationwide studies investigating the association between daily mean temperature and Kawasaki disease are lacking. This study aimed to examine the association between ambient temperature and Kawasaki disease by utilizing daily data from nationwide administrative claims databases. The daily number of Kawasaki disease patients younger than 15 years old, who were hospitalized from 2011 to 2022, was extracted from the nationwide administrative claims database of hospitalizations in Japan. Daily mean temperature data and relative humidity data were obtained from the Japan Meteorological Agency. Since the exposure of interest includes heat, hospitalizations during the five warmest months (May through September) were used for analysis. A time-stratified case-crossover study with conditional quasi-Poisson regression analysis was used to estimate the relative risk (RR) of weather exposure for Kawasaki disease hospitalization with a lag of 0-5 days by prefecture. Relative humidity was included in the model simultaneously to control for its potential confounding effect. Random-effects meta-analysis was used to estimate pooled RRs. There was a total of 48,784 cases of Kawasaki disease hospitalization during the study period, of which 87.9% were under 5 years of age. Exposure to high daily mean temperatures was associated with an increased risk of hospitalization for Kawasaki disease. Specifically, exposure to extreme high daily mean temperatures (99th percentile high temperature) was associated with higher risk of hospitalization by 33% (RR 1.33, 95% confidence interval (CI):1.08, 1.65). Similar results were obtained from sensitivity analysis. Future research should elucidate the mechanisms by which high temperature is associated with hospitalization for Kawasaki disease., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Kawasaki disease (KD) is a severe acute febrile illness and systemic vasculitis that causes coronary artery aneurysms in young children. Platelet hyperreactivity and an aberrant immune response are key indicators of KD; however, the mechanism by which hyperactive platelets contribute to inflammation and vasculopathy in KD remains unclear. A cytokine-mediated positive feedback loop between KD platelets and monocytes is identified. KD platelet-monocyte aggregates (MPAs) are mediated by an initial interaction of P-selectin (cluster of differentiation 62P, CD62p) and its glycoprotein ligand 1 (PSGL-1). This is followed by a coordinated interaction of platelet glycoprotein (GP)Ibα with monocyte CD11b. Monocyte-activated platelets initiate transforming growth factor (TGF)β1 release, which results in nuclear localization of nuclear factor kappaB in monocytes, therefore, driving the phenotypic conversion of classical monocytes (CD14 + CD16 - ) into proinflammatory monocytes (CD14 + CD16 + ). The platelet-activated monocytes release interleukin-1 and tissue necrotic factor-α, which promote further platelet activation. KD-induced inflammation and vasculopathy are prevented by inhibiting the components of this positive feedback loop. Notably, mice deficient in platelet TGFβ1 show less MPA and CD14 + CD16 +  monocytes, along with reduced inflammation and vasculopathy. These findings reveal that platelet-monocyte interactive proteins (CD62p/PSGL-1 and (GP)Ibα/CD11b) and cytokine mediators (platelet TGFβ1) are potential biomarkers and therapeutic targets for KD vasculopathy., (© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)

Kawasaki disease (KD) is an acute systemic vasculitis predominantly affecting infants and children under the age of 5. Recent studies have indicated that excessively released neutrophil extracellular traps (NETs) are involved in the progression of vasculitis. The purpose of this study was to investigate the role of NETs, especially their interaction with peripheral blood mononuclear cells (PBMCs), in the pathogenesis of KD. First, we demonstrated that the levels of NETs (cfDNA, MPO, and NE) in the serum of KD patients were significantly higher than those in healthy controls (HCs) and notably decreased after treatment. During the acute phase of KD, inflammatory markers (CRP and ESR) were positively correlated with NETs levels. Furthermore, we observed that neutrophils from KD patients in the acute phase produced elevated levels of NETs, and aspirin could effectively regulate the release of NETs. Additionally, NETs significantly increased the mRNA levels of NLRP3 and IL-1β in PBMCs, as well as the protein expression of NLRP3, caspase-1, ASC and gasdermin D, and the concentration of IL-1β in the cell supernatant. Moreover, NETs stimulated the production of reactive oxygen species (ROS) in PBMCs. N-acetylcysteine significantly reduced the expression of inflammatory factors and pyroptosis-related proteins in PBMCs. In conclusion, our findings suggest that NETs induce the generation of ROS, which in turn activates the NLRP3 inflammasome to mediate PBMCs pyroptosis and perpetuate inflammation in KD patients. This study reveals that targeting NETs or ROS could be a potential therapeutic approach for alleviating systemic inflammation, and that NETs may be a novel target for aspirin in the treatment of KD patients., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

The incidence of Kawasaki Disease has a peak in the winter months with a trough in late summer/early fall. Environmental/exposure factors have been associated with a time-varying incidence. These factors were altered during the COVID-19 pandemic. The study was performed through the International Kawasaki Disease Registry. Data from patients diagnosed with acute Kawasaki Disease and Multiple Inflammatory Syndrome-Children were obtained. Guideline case definitions were used to confirm site diagnosis. Enrollment was from 1/2020 to 7/2023. The number of patients was plotted over time. The patients/month were tabulated for the anticipated peak Kawasaki Disease season (December-April) and non-peak season (May-November). Data were available for 1975 patients from 11 large North American sites with verified complete data and uninterrupted site reporting. The diagnosis criteria were met for 531 Kawasaki Disease and 907 Multiple Inflammatory Syndrome-Children patients. For Multiple Inflammatory Syndrome-Children there were peaks in January of 2021 and 2022. For Kawasaki Disease, 2020 began (January-March) with a seasonal peak (peak 26, mean 21) with a subsequent fall in the number of cases/month (mean 11). After the onset of the pandemic (April 2020), there was no clear seasonal Kawasaki Disease variation (December-April mean 12 cases/month and May-November mean 10 cases/month). During the pandemic, the prevalence of Kawasaki Disease decreased and the usual seasonality was abolished. This may represent the impact of pandemic public health measures in altering environmental/exposure aetiologic factors contributing to the incidence of Kawasaki Disease.

Purpose: To summarize advances in research on the epidemiology, pathogenesis, diagnosis, and treatment of Kawasaki Disease (KD), a systemic inflammatory illness of unknown etiology that affects children globally., Recent Findings: The epidemiology of KD was affected by the COVID-19 pandemic and advances in molecular immunology and machine learning have enabled research into its pathogenesis. There is ongoing research into agents that can be used to intensify initial treatment and accumulating evidence supporting the use of certain rescue regimens for refractory disease over others. There is promise surrounding a new coronary artery aneurysm prediction model. Research into the post-acute morbidity of KD continues. The COVID-19 pandemic temporarily reduced the incidence of KD. The NLRP3 inflammasome plays a key role in KD pathogenesis. Intensified initial treatment benefits high-risk patients, yet no intensification regimen shows superiority over another. Corticosteroids, infliximab, or combination therapy with IVIg plus another agent may be superior rescue regimens compared to IVIg alone for refractory KD. The Son score, developed in North America, predicted coronary artery lesions in Japanese and Italian cohorts. Patients with a history of KD may carry long-term physical and emotional burdens that persist into adulthood yet appear to have typical neurocognitive development. Successful transition to adult healthcare presents a challenge., Competing Interests: Declarations. Conflict of Interest: The authors declare no competing interests. Human and Animal Rights and Informed Consent: This article does not contain any studies with human or animal subjects performed by any of the authors., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Kawasaki disease (KD) primarily affects the pediatric population and exhibits a notable incidence of drug resistance, resulting in coronary artery damage and thrombosis. This study aimed to identify innovative therapeutic targets for KD treatment. By harnessing single-cell data derived from peripheral blood mononuclear cells, we identified differentially expressed genes. Through the integration of eQTL data and Mendelian randomization analysis, we identified FCGR3B and S100A12 were causally linked to KD. The DrugBank database showed their potential as drug target candidates. GSEA further elucidated their roles on coronary artery damage and thrombosis. Furthermore, we have confirmed that the ligand-FCGR3B complex enhances the intracellular calcium concentration (Ca 2+ ) within the cytoplasm, which in turn accelerates the secretion of S100A12, a pro-inflammatory cytokine that targets endothelial cells, from neutrophils. By integrating existing research, we proposed a synergistic effect that FCGR3B-S100A12 pathway positively modulates the development of coronary artery damage and thrombus formation, suggesting their perspectives in clinical treatment., Competing Interests: Declaration of competing interest The authors declare there are no competing interests., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Ultrasonography (US), as a routine examination for evaluating coronary artery lesions (CAL) in children with Kawasaki disease (KD), has strong subjectivity and limitations. Non-contrast enhanced coronary magnetic resonance angiography (NCE-CMRA) is sensitive and reliable in displaying the segments of coronary arteries (CA)., Purpose: To evaluate the CA using NCE-CMRA, to compare NCE-CMRA with US, and to assess the correlation between KD-related inflammatory factors and the occurrence of CAL., Study Type: Retrospective., Population: 61 children with KD who had undergone NCE-CMRA. Ultimately, 52 cases were included (32 males and 20 females), with an average of 5.9 ± 0.3 years old., Field Strength/sequence: 3-T, 3D balanced turbo field echo sequence., Assessment: NCE-CMRA and US coronary visualization rates were compared in 41 children who were imaged with both techniques. Inflammatory factors were compared between CAL and normal coronary artery (NCA) subgroups. In the CAL group, correlations of these inflammatory factors with CAL parameters were investigated., Statistical Tests: Comparison between groups was performed by the two independent samples t-test; the comparison of enumeration data between groups was performed by chi-square test. Receiver operating characteristic (ROC) curve analysis was performed to determine the sensitivity of inflammatory factors for detecting CAL. The correlation between CAL and inflammatory indexes was analyzed by multiple linear regression. A P value <0.05 was considered statistically significant., Results: NCE-CMRA visualized significantly more segments than US (76% vs. 46%). There were significant differences in PLT, CRP, ESR, and D-dimer between the CAL and NCA groups. ROC curve analysis showed that the sensitivities of these four indicators in diagnosing CAL were 39%, 44%, 72%, and 61%, respectively, at cut-off points of 562.5 × 10 9 /L, 48.93 mg/L, 45.5 mm/h, and 0.5 mg/L, respectively., Data Conclusion: The combination of NCE-CMRA and inflammatory factors is helpful for the early diagnosis and disease severity of CAL in children with KD., Level of Evidence: 3 TECHNICAL EFFICACY: Stage 2., (© 2024 International Society for Magnetic Resonance in Medicine.)

Systemic vasculitis encompasses a wide range of conditions characterized by varying degrees of inflammation in blood vessels. Although the etiology of vasculitis remains unclear, accumulated data suggest that it is triggered in genetically predisposed individuals by the concurrence of certain environmental factors. The importance of the genetic component has been consistently supported by evidence of familial aggregation, differential prevalence by ethnicity, and multiple genetic associations with disease susceptibility and severity reported in recent years. The strongest association signals in most vasculitides correspond to genetic variants within the HLA region, suggesting an important role of the immune system in its pathophysiology. However, each type of vasculitis has distinct defining HLA association markers, likely due to disease-specific differences in antigenic drivers. Furthermore, other genetic polymorphisms located outside the HLA region play an important role in susceptibility to different vasculitides. More recent research has assessed the shared genetic susceptibility evident across different vasculitides. Future studies should focus on the identification of genetic markers that can serve as reliable biomarkers for early diagnosis, prognosis, and treatment response in systemic vasculitis., Competing Interests: Declaration of competing interest The authors declare no conflict of interest related to this study., (Copyright © 2024. Published by Elsevier Ltd.)

Introduction: Kawasaki disease (KD) is a medium vessel vasculitis mainly affecting children below the age of 5. KD is the leading cause of acquired heart disease in developed countries. Diagnosis of KD is clinical, and there are no pathognomonic laboratory tests to confirm the diagnosis. There is a paucity of studies that have utilized proteomic approach for biomarker discovery in KD. Identification of these biomarkers may be helpful for early and more effective diagnosis and may aid in the treatment of KD., Area Covered: The present review focuses on studies that have utilized the proteomic approach in the identification of biomarkers in patients with KD. We have divided these biomarkers into three different categories: the biomarkers used for (a) assessment of risk of KD; (b) assessment of risk of coronary artery aneurysms; and (c) assessment of treatment resistance., Expert Opinion: Efforts to improve the clinical and diagnostic evaluation of KD have focused on general markers of inflammation that are not specific for KD. Identification of a proteomic-based biomarker can reliably and specifically differentiate KD from other diseases and could help in the prompt diagnosis. Comprehensive analysis of the serum proteome of patients with KD may be helpful in identifying candidate protein biomarkers.

Background: Children with intravenous immunoglobulin (IVIG) resistant Kawasaki disease (KD) are at higher risk of developing coronary artery (CA) aneurysm. Early identification of high-risk patients using a predictive tool would allow for earlier interventions to prevent cardiac complications., Methods: Children with KD who were admitted to five selected hospitals in Malaysia between 2008 and 2018 and received 2 g/kg of IVIG within 10 days from the onset of illness were included. Predictors of IVIG resistance in KD were determined using multiple logistic regression analysis. An optimal cut-off point was set using receiver operative characteristic curve and a final multiple logistic regression analysis was performed entering these cut-off points. A new scoring system was constructed., Results: A total of 276 patients were included. IVIG resistance occurred in 9.1 % of them. Total bilirubin [OR 7.37; 95 % CI (2.18, 24.83)], male sex [OR 0.34; 95 % CI (0.10, 1.19)], C-reactive protein (CRP) [OR 0.17; 95 % CI (0.02, 1.38)] and neutrophils [OR 0.25; 95 % CI (0.05, 1.21)] were found to be significant predictors for IVIG resistance. The findings led to the development of a new predictive tool called the Hibiscus score, which scored 1 point each for neutrophils ≥60 %, CRP ≥80 mg/L, and male sex, while total bilirubin ≥9.4 μmol/L scored 2 points. A cut-off point of ≥4 with this prediction score yielded a sensitivity of 78.9 % and specificity of 80.5 %, with area under the curve of 0.835 [95 % CI (0.752, 0.919)]. CA aneurysms occurred in 6.7 % of IVIG responders and 32 % of IVIG-resistant children (p < 0.001)., Conclusion: The findings suggest that the Hibiscus score has a higher predictive power than the existing scoring systems for IVIG resistance in children with KD in Malaysia. However, external validation is required to enable its use to guide treatment decisions., Competing Interests: Declaration of competing interest The authors declare that there is no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Multisystem inflammatory syndrome in children (MIS-C) presents some clinical overlap with Kawasaki disease (KD). Although KD is common in Japan, the clinical characteristics of MIS-C in Japan remain unknown. Therefore, we aimed to determine the epidemiological and clinical features of MIS-C in Japan., Methods: Using a case reporting form, a nationwide registry was created between November 2020 and March 2023, involving 2,080 facilities throughout Japan. We prospectively and retrospectively enrolled patients with MIS-C. The primary outcomes were the number and incidence rates of children with MIS-C. The secondary outcomes included clinical features, such as KD phenotype, organ involvement, shock, intensive care unit admission, and coronary artery lesions., Results: Among 398 patients registered, central review identified 129 MIS-C cases (mean age: 8·8 ± 3·7 years). The overall incidence rate was estimated to be 1·5 per 100,000 COVID-19 cases, exhibiting a decline as the COVID-19 pandemic progressed, from 12·3 cases (Pre-Delta) to 1·3 cases (Omicron); 80% of MIS-C cases occurred during the Omicron variant predominant period, and 72% of children with MIS-C met the KD criteria. Cardiovascular (88%) and gastrointestinal (90%) involvement were frequent. In Japan, MIS-C cases showed comparatively less severe clinical features, with shock in 29% and admission to the intensive care unit in 12% of cases. Coronary artery lesions were identified in 15 cases (11·6%), irrespective of the presence of shock. No fatalities were reported., Conclusion: The incidence of MIS-C was low in Japan. The clinical features distinctively exhibited a more KD-like phenotype, with less severe clinical features., Competing Interests: Declarations. Ethics Approval and Consents: This study was approved by the Institutional Review Board of Jichi Medical University (IRB: 23-026) and the respective multicenter institutes involved in this study. The participating sites obtained approval from their local IRB if needed. Written informed consent was not necessary as only deidentified data were used; instead, an opt-out opportunity was made available on the websites of the Department of Public Health at Jichi Medical University and at each participating facility. This study was performed in line with the principles of the Declaration of Helsinki. Competing Interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: The microRNA-200 family plays a key role in inflammatory and vascular processes, making it a relevant target for Kawasaki disease, a vasculitis with coronary complications. This study aimed to evaluate the diagnostic potential of urinary exosomal microRNA-200 family members in Kawasaki disease patients., Methods: Urine samples from 15 Kawasaki disease patients and 15 healthy controls underwent total exosome isolation and high-throughput sequencing. Differential expression of microRNA-200 family members was validated using quantitative real-time polymerase chain reaction. Diagnostic potential was assessed via receiver operating characteristic analysis, and correlations with clinical parameters were evaluated using Spearman correlation., Results: High-throughput sequencing identified upregulation of microRNA-429, microRNA-200b-3p/5p, microRNA-141-3p, microRNA-200a-3p/5p, and microRNA-200c-3p in Kawasaki disease patients. We confirmed significant upregulation of microRNA-200a-3p/5p, microRNA-200b-3p/5p, and microRNA-429, with receiver operating characteristic analysis showing high diagnostic potential for these microRNAs (area under the curves of 0.844, 0.791, 0.942, 0.842, and 0.898, respectively) and a combined analysis yielding a perfect area under the curve of 1.000. MicroRNA-141 and microRNA-200c-3p/5p, however, showed no significant diagnostic value. MicroRNA-200a-3p and microRNA-200a-5p were positively correlated with white blood cells, platelet counts, and C-reactive protein, while microRNA-200b-3p and microRNA-429 were positively correlated with white blood cells, platelet counts, erythrocyte sedimentation rate, and C-reactive protein. microRNA-200b-5p showed moderate correlations with platelet counts and erythrocyte sedimentation rate., Conclusion: Urinary exosomal microRNA-200 family members, especially microRNA-200a-3p/5p, microRNA-200b-3p/5p, and microRNA-429, demonstrate strong diagnostic potential for Kawasaki disease, correlating with key inflammatory markers. MicroRNA-141 and microRNA-200c did not demonstrate significant diagnostic utility.

Background: To explore the clinical characteristics, related factors, and prognosis of Kawasaki disease (KD) combined with acute febrile cholestasis and improve the understanding of the liver complications of KD to avoid misdiagnosis and missed diagnosis., Methods: We retrospectively analyzed the demographic, clinical, and laboratory data of 1803 patients with KD between January 2019 and July 2023 in our hospital. Based on the presence of cholestasis, patients were divided into the cholestatic and control groups. Logistic regression analysis was performed for the statistically significant indicators between the two groups to examine the risk factors for KD with coronary artery abnormalities (CAA) and intravenous immunoglobulin (IVIG) unresponsiveness. Additionally, patients with KD and cholestasis were compared with patients with acute febrile cholestasis due to other causes during the same period., Results: Compared to the control group (n = 1720), patients in the cholestatic group (n = 83) were older, had higher levels of white blood cell count (WBC), C-reactive protein (CRP), D-dimer, N-terminal pro-brain natriuretic peptide (NT-proBNP), a shorter fever duration, and high incidences of IVIG unresponsiveness and CAA. KD was the leading cause of acute febrile cholestasis in children (72.6%). In the multivariate logistic regression analysis, younger age, cholestasis, hypoalbuminemia, and a high NT-proBNP level were risk factors for IVIG unresponsiveness, whereas male sex, longer fever duration before treatment, and high alanine aminotransferase (ALT), and CRP levels were risk factors for CAA., Conclusion: KD with cholestasis was associated with a higher risk of IVIG unresponsiveness and coronary artery abnormalities. KD was the leading cause of acute febrile cholestasis in children. Attention to the possibility of KD is warranted in children with acute febrile cholestatic jaundice, especially if associated with elevated WBC, CRP, and D-dimer levels, or hypoalbuminemia., Competing Interests: Declarations. Ethics approval and consent to participate: Since it was a retrospective study involving human data, informed consent was waived. Approval wasgranted by the Ethics Committee of Shengjing Hospital of China Medical University (approval No. 2023PS1065K Shenyang China, Date 04/09/2023). This study was performedin line with the principles of the Declaration of Helsinki. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Kawasaki disease (KD), an acute systemic vasculitis that primarily affects children under 5 years of age, is the leading cause of acquired heart disease in this age group. Recent studies propose a novel perspective on KD's etiology, emphasizing the gastrointestinal (GI) tract, particularly the role of gut permeability. This review delves into how disruptions in gut barrier function trigger systemic inflammatory responses, exacerbate vascular inflammation, and contribute to coronary artery aneurysms. Evidence suggests that children with KD often exhibit increased gut permeability, leading to an imbalance in gut immunity and subsequent gut barrier damage. These changes impact vascular endothelial cells, promoting platelet aggregation and activation, thereby advancing severe vascular complications, including aneurysms. Additionally, this review highlights the correlation between GI symptoms and increased resistance to standard treatments like intravenous immunoglobulin (IVIG), indicating that GI involvement may predict therapeutic outcomes. Advocating for a new paradigm, this review calls for integrated research across gastroenterology, immunology, and cardiology to examine KD through the lens of GI health. The goal is to develop innovative therapeutic interventions targeting the intestinal barrier, potentially revolutionizing KD management and significantly improving patient outcomes., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Tao and Lang.)

Intravenous immunoglobulin (IVIg) is a medical preparation used as replacement therapy for patients with immunodeficiencies. Over time, IVIg's anti-inflammatory and immunomodulatory effects have been recognized, which have led to the approval of this therapy in the treatment of various pathologies, such as Kawasaki disease, immune thrombocytopenia, and Guillain-Barré syndrome. There are numerous studies in the literature regarding the off-label use of IVIg in the treatment of autoimmune diseases (e.g. myositis and vasculitis), and hematological disorders. Since the role of immunoglobulins in fields other than replacement therapy is now consolidated, in this study we carried out a review of the literature to evaluate the main uses of IVIg therapy. We have focused our attention on the treatment of autoimmune, neurological, hematological, dermatological and pediatric diseases. Furthermore, our analysis of the literature also extended to the potential use of IVIg as an adjuvant treatment of long COVID-19. From our analysis, we found consistent data about IVIg's effectiveness in treating numerous clinical conditions. Treatment with IVIg represents a second-line approach or a valid adjuvant to standard therapies capable of positively influencing the clinical course of many pathologies and reducing or avoiding side effects of standard therapies, with a good safety profile., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Maria Giovanna Danieli and Yehuda Shoenfeld are serving in the Editorial Board of Autoimmunity Reviews. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Introduction: Currently the diagnosis of Kawasaki disease is still heavily reliant on clinical criteria which may be subject to interpretation or mimic other common febrile diseases of childhood. Biomarkers that can aid in the accurate and timely diagnosis of KD are of great clinical utility., Areas Covered: A literature search of PubMed was performed using the key words: Kawasaki disease, diagnosis, biomarkers, proteomics and transcriptomics. In this article we review biomarkers that are widely clinically available including NT-ProBNP and ferritin. We also include promising novel biomarkers that have been identified through newer transcriptomic and proteomic techniques., Expert Opinion: While the identification of biomarkers that can accurately assist in diagnosing patients with KD is a promising field of research, more still remains to be done to in order to validate new biomarkers in larger cohorts, and to set standardized cutoff values for potential biomarkers that are currently clinically available. Further research is needed before KD biomarkers that are consistent, readily available, and cost-effective can be a clinical reality.

Background: Predicting resistance to intravenous immunoglobulin (IVIG) in the treatment of Kawasaki disease (KD) remains a focus of research. Fibrinogen and albumin in systemic inflammation play an important role. This study aims to investigate the predictive value of fibrinogen to albumin ratio (FAR) for initial IVIG resistance in patients with KD., Methods: The study prospectively recruited 962 patients with KD between July 2015 and June 2022. The serum characteristics of the two groups were compared by comparing fibrinogen and albumin, as well as other laboratory and clinical data between the IVIG-responsive and IVIG-resistant groups. Multivariate logistic regression was used to explore the relationship between FAR and IVIG resistance. Receiver operating characteristic (ROC) curves were used to determine the effectiveness of FAR in predicting initial IVIG resistance., Results: Our results demonstrated that IVIG-resistant patients had significantly higher fibrinogen levels (603.35 ± 99.00 mg/L), FAR (17.30 ± 3.31), and lower albumin (35.47 ± 5.24 g/L) compared to IVIG-responsive patients (fibrinogen 572.35 ± 145.75 mg/L; FAR 15.08 ± 4.32; albumin 38.52 ± 4.55 g/L). 15.20 was the best cut-off value of FAR for predicting initial IVIG resistance. The sensitivity was 72.5%, the specificity was 51.3%, the positive predictive value was 91.8%, and the negative predictive value was 20.0%. Multivariate logistic regression analysis, found that FAR was an independent predictor of initial IVIG resistance in KD children., Conclusions: The FAR was an independent risk factor for initial IVIG resistance, its predictive power for initial IVIG resistance exceeded that of albumin and fibrinogen alone. FAR may not be suitable as a single marker but might serve as a complementary laboratory marker to accurately predict initial IVIG resistance in KD., Competing Interests: The authors declare no conflict of interest., (Copyright: © 2024 The Author(s). Published by IMR Press.)

Background: Giant coronary artery aneurysms and myocardial fibrosis after Kawasaki disease may lead to devastating cardiovascular outcomes. We characterised the vascular and myocardial outcomes in five selected Kawasaki disease patients with a history of giant coronary artery aneurysms that completely regressed., Methods: Five patients were selected who had giant coronary artery aneurysm in early childhood that regressed when studied 12-33 years after Kawasaki disease onset. Coronary arteries were imaged by coronary CT angiography, and coronary artery calcium volume scores were determined. We used endocardial strain measurements from CT imaging to assess myocardial regional wall function. Calprotectin and galectin-3 (gal-3) as biomarkers of inflammation and myocardial fibrosis were measured by enzyme-linked immunosorbent assay., Results: The five selected patients with regressed giant coronary artery aneurysms had calcium scores of zero, normal levels of calprotectin and gal-3, and normal appearance of the coronary arteries by coronary computed tomography angiography. CT strain demonstrated normal peak systolic and diastolic strain patterns in four of five patients. In one patient with a myocardial infarction at the time of Kawasaki disease diagnosis at the age of 10 months, CT strain showed altered global longitudinal strain, reduced segmental peak strain, and reduced diastolic relaxation patterns in multiple left ventricle segments., Conclusions: These patients illustrate that regression of giant aneurysms after Kawasaki disease is possible with no detectable calcium, normal biomarkers of inflammation and fibrosis, and normal myocardial function. Individuals with regressed giant coronary artery aneurysm still require longitudinal surveillance to assess the durability of this favourable outcome.

Objective : We aimed to determine whether the severity of acute Kawasaki disease (KD) can be predicted based on whether a patient remains febrile or becomes afebrile immediately after the completion of initial immunoglobulin treatment (IVIG). Methods : This retrospective cohort study at a single institution involved 306 patients with KD. They were categorized into four groups according to their fever status at two specific time points (end of the initial IVIG treatment and 24-36 h later): Group F-F, patients who remained febrile at both time points; Group F-AF, patients who were febrile at the end of the initial IVIG treatment but became afebrile 24-36 h later; Group AF-F, patients who were afebrile at the end of the initial IVIG treatment but became febrile 24-36 h later; and Group AF-AF, patients who remained afebrile at both time points. The clinical characteristics of the groups were compared. Results : Group F-F (n = 38) showed a significantly higher incidence of CAAs compared to Group AF-F (n = 37), 55.3% vs. 0.0% ( p < 0.0001), although both groups were classified as resistant to the initial IVIG. Conclusions : In Japanese patients with acute KD, the presence or absence of fever at the completion of initial IVIG treatment may serve as an early predictor of the occurrence of CAAs. An earlier secondary treatment may be warranted for patients who are in a febrile state immediately after the completion of the initial IVIG treatment. Future research should include a prospective cohort study with a larger number of KD cases across multiple institutions to analyze the effects of other contributing factors related to CAL formation.

Kawasaki disease (KD) is an acute febrile rash that is primarily characterized by systemic vasculitis and is the leading cause of childhood-acquired heart disease. At present, a KD diagnosis is solely dependent on clinical symptoms and effective diagnostic markers are unavailable. Ferroptosis, a novel form of programmed cell death, contributes to the pathophysiology of infectious diseases. The present study aimed to identify key ferroptosis-related genes (FRGs) involved in the pathological process of KD and thus potential diagnostic biomarkers for this disease. For this purpose, differentially expressed-FRGs (DE-FRGs) between patients with KD and healthy controls were screened. The least absolute shrinkage and selection operator (LASSO) algorithm and a logistic regression model combined with receiver operating characteristic analysis were then used to identify and assess ferroptosis-related markers. Additionally, immune cell infiltration landscapes in the KD and control groups were evaluated using CIBERSORT. Moreover, the predictive value of the identified markers was validated in the clinical samples as well as vascular endothelial cells. A total of 10 DE-FRGs were screened from the KD and control samples. These 10 DE-FRGs were then applied to the LASSO model and 6 key ferroptosis-related markers were obtained. The subsequent Gene Set Variation Analysis results suggested that high expression levels of these markers were closely associated with innate immune activation and metabolism, while low expression was mainly linked to adaptive immune-related pathways. In addition to validating each gene in the training and validation sets, the diagnostic potential of these markers was assessed utilizing KD samples obtained from Shenzhen Baoan Women's and Children's Hospital. As a result, MAPK14, SLC2A3 and PGD were selected as potential diagnostic markers for KD. Additionally, changes in the expression of marker genes during inflammatory activation of vascular endothelial cells were measured by reverse transcription-quantitative PCR. The results of the present study will help to understand the role of FRGs in the pathogenesis of KD. Moreover, the identified FRGs may serve as diagnostic biomarkers, providing new strategies for KD prediction and treatment., Competing Interests: The authors declare that they have no competing interests., (Copyright: © 2024 Yan et al.)

Background: Kawasaki disease (KD) is an acute pediatric vasculitis that can lead to coronary artery aneurysms and severe cardiovascular complications, often presenting with obvious fever in the early stages. In current clinical practice, distinguishing KD from other febrile illnesses remains a significant challenge. In recent years, some researchers have explored the potential of machine learning (ML) methods for the differential diagnosis of KD versus other febrile illnesses, as well as for predicting coronary artery lesions (CALs) in people with KD. However, there is still a lack of systematic evidence to validate their effectiveness. Therefore, we have conducted the first systematic review and meta-analysis to evaluate the accuracy of ML in differentiating KD from other febrile illnesses and in predicting CALs in people with KD, so as to provide evidence-based support for the application of ML in the diagnosis and treatment of KD., Objective: This study aimed to summarize the accuracy of ML in differentiating KD from other febrile illnesses and predicting CALs in people with KD., Methods: PubMed, Cochrane Library, Embase, and Web of Science were systematically searched until September 26, 2023. The risk of bias in the included original studies was appraised using the Prediction Model Risk of Bias Assessment Tool (PROBAST). Stata (version 15.0; StataCorp) was used for the statistical analysis., Results: A total of 29 studies were incorporated. Of them, 20 used ML to differentiate KD from other febrile illnesses. These studies involved a total of 103,882 participants, including 12,541 people with KD. In the validation set, the pooled concordance index, sensitivity, and specificity were 0.898 (95% CI 0.874-0.922), 0.91 (95% CI 0.83-0.95), and 0.86 (95% CI 0.80-0.90), respectively. Meanwhile, 9 studies used ML for early prediction of the risk of CALs in children with KD. These studies involved a total of 6503 people with KD, of whom 986 had CALs. The pooled concordance index in the validation set was 0.787 (95% CI 0.738-0.835)., Conclusions: The diagnostic and predictive factors used in the studies we included were primarily derived from common clinical data. The ML models constructed based on these clinical data demonstrated promising effectiveness in differentiating KD from other febrile illnesses and in predicting coronary artery lesions. Therefore, in future research, we can explore the use of ML methods to identify more efficient predictors and develop tools that can be applied on a broader scale for the differentiation of KD and the prediction of CALs., (©Jinpu Zhu, Fushuang Yang, Yang Wang, Zhongtian Wang, Yao Xiao, Lie Wang, Liping Sun. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 18.11.2024.)

Background: Coronary artery aneurysm (CAA) poses significant cardiovascular risks, particularly in Kawasaki disease (KD) patients. This systematic review and meta-analysis aim to evaluate and compare antithrombotic strategies in preventing CAA formation secondary to Kawasaki disease and the ensuing CAA cardiovascular complications., Methods: Following PRISMA guidelines, we systematically searched major databases, namely PubMed, Scopus, Web of Science, and Embase. Major adverse cardiovascular events (MACE), myocardial infarction (MI), stenosis, bleeding, occlusion, and coronary artery lesion (CAL) formation were primary outcomes. Consolidated Standards of Reporting Trials (CONSORT) and Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) scores assessed study quality. A meta-analysis, as well as sensitivity analysis and meta-regression, was performed to compare the efficacy of pharmacological strategies on the outcomes., Results: The study included 21 studies with 1045 patients for CAA complications and 41536 patients for CAA formation prevention. In children with CAA secondary to Kawasaki disease, the addition of warfarin to aspirin was associated with a significantly lower odds of myocardial infarction (OR = 0.26, 95% CI: 0.11-0.60, I 2  = 25%) and mortality (OR = 0.18, 95% CI: 0.04-0.88, I 2  = 0%) compared to aspirin alone. However, there was no significant difference in MACE (OR = 0.38, 95% CI: 0.08-1.93, I 2  = 60%) and occlusion (OR = 0.17, 95% CI: 0.02-1.92, I 2  = 58%). Sensitivity analysis showed reduced thrombosis (OR = 0.29, 95% CI: 0.14-0.62, I 2  = 0%), MACE (OR [95% CI] = 0.22[0.06-0.84], I 2  = 46%), and occlusion (OR [95% CI] = 0.08[0.02-0.44], I 2  = 36%). Meta-regression did not yield significant results., Conclusions: As for the acute phase of KD, no benefit was conferred from adding high-dose aspirin to the routine IVIG alone regimen. However, the complexity of outcomes and the diversity in antithrombotic interventions underscore the need for tailored approaches and further research., Competing Interests: Declarations Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. While circulating neutrophils are increased and activated during acute KD, it is unclear whether neutrophils and neutrophil extracellular traps (NETs) contribute to the pathogenesis of KD. Peptidylarginine deiminase 4 (PAD4), an enzyme involved in protein citrullination and essential for NETs formation, is implicated in the pathogenesis of various diseases. Here, we used the Lactobacillus casei cell wall extract (LCWE)-induced mouse model of KD vasculitis to determine the contribution of PAD4 in KD vasculitis. We found that the pan-PADs inhibitor, Cl-amidine, significantly reduced LCWE-induced cardiovascular lesions, but neutrophil-specific Padi4 KO mice did not impact the development of KD vasculitis. While in vitro treatment of macrophages, which highly express Padi4, with Cl-amidine inhibited IL-1β secretion, macrophage-specific Padi4 KO mice did not reduce the lesions. Padi4-/- mice also developed KD vasculitis, AFM30a, a PAD2 inhibitor, significantly reduced KD vasculitis in Padi4-/- mice, indicating a compensatory role of PAD2 in PAD4 deficiency. We also identified several citrullinated proteins in macrophages with constitutively active NLRP3 inflammasome that were inhibited by Cl-amidine treatment, suggesting that protein citrullination participates in NLRP3 inflammasome activation. These data indicate a dispensable role for PAD4-dependent NETs formation, and a redundant role of PAD2 and PAD4 in this murine KD vasculitis. The cardioprotective effects of Cl-amidine to reduce the severity of murine KD vasculitis are not limited to PAD4 inhibition and may include decreased citrullination in the inflammasome pathway., (© The Author(s) 2024. Published by Oxford University Press on behalf of the British Society for Immunology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Objectives: Giant coronary artery aneurysms are rare but potentially fatal complications of Kawasaki disease. The lack of evidence-based recommendations on their management and treatment cause guidelines and practices to differ. We aimed to assess these variations., Methods: An anonymous online survey regarding surveillance, imaging, pharmacological management, and interventional practices was distributed among 134 physicians attending to Kawasaki disease patients worldwide. A p-value of <0.05 was deemed significant., Results: The majority (60%) of respondents were general paediatric cardiologists, and 29% interventional specialists. The average years in practice was 15 ± 9.6. Physicians from Asia had the most experience with giant coronary artery aneurysms. American practitioners preferred combining anticoagulants with aspirin. Beta-blockers and statins were more likely used in teenagers versus younger children. Cardiac catheterisation was most (52%) chosen for coronary surveillance in patients with echocardiogram anomalies, followed by Coronary CT-angiography. The indications for coronary intervention were split among respondents, regardless of geographic region or experience. The preferred treatment of coronary stenosis was percutaneous intervention (69%) versus bypass surgery. For thrombosis, thrombolytics (50%) were preferred over percutaneous (39%) and surgical (11%) interventions. Most (92%) preferred intervening in young children in a paediatric facility but were split between a paediatric and adult facility for older children. Most chose combined management by adult and paediatric specialists for either age-scenarios (70, 82%)., Conclusion: As identified by our study, the lack of large studies and evidence-based recommendations cause uncertainty and ambivalence towards certain treatments. International collaborative efforts are needed to provide more robust evidence in the management of these patients.

Background: Coronary artery lesions are the most severe complications of Kawasaki disease. Despite recent advances, evidence of the association between risk factors and coronary artery lesion is lacking. In this study, we demonstrated the potential clinical indicators that could assist to evaluate the prevalence of coronary artery lesion among paediatric patients with Kawasaki disease., Methods: We retrospectively enrolled 260 paediatric patients with Kawasaki disease. Patients with coronary dilation, coronary aneurysm, and intimal thickening of coronary arteries were included in this study. Medical records of each patient were collected. Logistic regression analysis was performed to explore risk factors and the occurrence of coronary artery lesion in patients with Kawasaki disease., Results: Respectively, 64 (24.6%), 39 (15%), and 56 patients (21.5%) of the participants had coronary dilation, coronary aneurysm, and intimal thickening of coronary arteries. Univariate analysis revealed that age, gender, duration of fever, time of initial use of intravenous immunoglobulin, erythrocyte sedimentation rate, white blood cell counts, time of platelet increase, the maximum value of platelet, albumin, and immunoglobulin G level was associated with coronary artery lesion. In multivariable logistic analysis, those younger and mainly males were associated with all three outcomes of coronary artery lesion, lower serum albumin levels, and later initial use of intravenous immunoglobulin were linked to a higher risk of coronary dilation and coronary aneurysm., Conclusions: The potential risk factors that could be used to estimate the occurrence of coronary artery lesion in Kawasaki disease patients are young age, male, lower serum albumin lever, and later initial use of intravenous immunoglobulin. However, long-term follow-up and multi-centre studies are required to verify our findings in the future.

This case is a 4-month-old patient with Kawasaki disease who showed coronary artery lesions after a disease relapse. Following the guidelines from the Randomised Controlled Trial to Assess Immunoglobulin plus Steroid Efficacy, the patient initially saw an improvement in symptoms. However, a relapse occurred despite low levels of C-reactive protein, leading to significant coronary artery growth. Treatment with a third dose of intravenous immunoglobulin and cyclosporine led to a slow reduction in the size of the coronary artery abnormalities. This case highlights the difficulty in monitoring Kawasaki disease progression through clinical symptoms and C-reactive protein levels alone. We also emphasise the necessity of echocardiographic monitoring in patients receiving anti-inflammatory treatments, including steroids, because coronary artery problems can arise or continue without the usual signs of Kawasaki disease or increased C-reactive protein levels.

Background: Patients with Kawasaki disease (KD) with coronary artery involvement require long-term cardiac care. Although respective evidence-based recommendations are missing, cardiac catheterization is still considered the gold standard for diagnosing detailed coronary pathology. Therefore, to better understand coronary artery pathology development, we conducted a survey to document and evaluate cardiac catheterization data in a European population., Methods and Results: We retrospectively analyzed cardiac catheterization data from KD children from the year 2010 until April 2023. This registry covers basic acute-phase clinical data, and more importantly, detailed information on morphology, distribution, and the development of coronary artery pathologies. A total of 164 mainly White patients (65% boys) were included. A relevant number of patients had no coronary artery aneurysm (CAA) at the cardiac catheterization, indicating that distal CAAs were almost exclusively detected alongside proximal CAAs. Patients with multiple CAAs revealed a significant positive correlation between the number of CAAs and their dimensions in diameter and in length. Location of the CAA within the coronary artery, age at onset of KD, or natal sex did not significantly influence CAA diameters, but CAAs were longer in older children and in boys., Conclusions: That distal CAAs were only present together with proximal ones will hopefully reduce diagnostic CCs in patients with KD without echocardiographically detected proximal CAAs. Furthermore, this study gives valuable insights into dimensional specifics of CAAs in patients with KD. As an ongoing registry, future analyses will further explore long-term outcomes and performed treatments, helping to refine clinical long-term strategies for patients with KD., Registration: URL: https://drks.de/; Unique Identifier: DRKS00031022.

Objectives: To investigate the relationship between recent antibiotic exposure and the development of coronary artery lesions (CALs) during the clinical course of Kawasaki disease (KD)., Design: Data were obtained from the 25th nationwide epidemiological survey of KD conducted in Japan from 2017 to 2018. Baseline characteristics and clinical course were compared between Antibiotics (+) and Antibiotics (-) groups., Setting: Nationwide survey of KD in Japan., Participants: KD patients were enrolled by response to a questionnaire sent to physicians working in pediatrics at hospitals with >100 beds., Exposure: Antibiotic exposure within one week before the first hospital visit as KD patients., Main Outcome Measures: The relationship between recent antibiotic exposure and the development of coronary artery lesions (CALs)., Results: Out of 28,265 KD patients, 12,918 (45.7%) received antibiotics. In KD patients who received antibiotics in the week before KD diagnosis, the frequency of coronary artery lesions (CALs) at each phase were significantly higher compared to those who did not receive antibiotics. In further analysis using propensity score matching, recent antibiotic exposure and the initial IVIG resistance were associated with CALs at the acute and the sequelae phase. After adjusting for the status of initial IVIG resistance, recent antibiotic exposure remained associated with CALs during the acute phase (adjusted OR 1.29, 95%CI 1.16, 1.43) and the sequelae phase (1.26, 95%CI 1.04, 1.52)., Conclusions: These observations suggest that recent antibiotic exposure might be associated with higher frequency of CAL development in KD patients, possibly by altering the gut microbiota and diminishing beneficial bacteria., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2024 Ansai, Yamada, Masuda, Imadome, Yashiro, Noval Rivas, Arditi, Nakamura and Abe.)

Vasculitis in children represents a diverse group of diseases characterized by inflammation of blood vessels, which can lead to significant morbidity if not promptly recognized and managed. This review explores the epidemiology, pathophysiology, classification, and management of key pediatric vasculitides. Classification based on vessel size aids in diagnosis and treatment. Understanding these conditions" clinical features and therapeutic options is critical for improving pediatric patient outcomes and preventing long-term complications. Continued research is essential for refining treatment strategies and enhancing patient care.

Background: The role of inflammatory cytokines in Kawasaki disease (KD) pathogenesis is known, but causal relationships are unclear. This study investigates these connections using Mendelian randomization (MR)., Methods: Genetic variations associated with KD were obtained from a GWAS including 119 cases and 6071 controls of European ancestry. Genetic data on inflammatory cytokines were sourced from a GWAS of 8,293 healthy participants., Results: The study identified significant associations between higher levels of macrophage colony stimulating factor (M-CSF), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and increased risk of KD. The odds ratios (OR) were 1.04 (95% CI: 1.01-1.08, p  = 0.010) for M-CSF, 1.03 (95% CI: 1.01-1.05, p  = 0.026) for MCP-1, and 1.02 (95% CI: 1.01-1.04, p  = 0.027) for TRAIL., Conclusion: This study suggests that M-CSF, MCP-1, and TRAIL are potentially involved in the etiology of KD.

Kawasaki disease (KD) is a disease characterized by systemic immune vasculitis that often involves coronary arteries and can result in long-term cardiovascular sequelae. Different strategies for treatment of KD-and KD-induced coronary artery lesions are currently under investigation, including passive immunization with anti-TNFα monoclonal antibodies (mAbs). Herein, we examine the potential therapeutic capabilities of a novel type of TNFα-targeting agent based on an affibody molecule possessing fundamentally different properties than mAbs. Using phage display technology, we successfully screened and obtained three TNF-α binding affibody molecules and confirmed their high binding affinity and specificity for recombinant and native TNF-α by surface plasmon resonance (SPR), confocal double immunofluorescence and coimmunoprecipitation assays. Moreover, by binding to TNF-α, the affibody molecules could effectively neutralize TNFα-induced L929 cytotoxicity. To increase the targeting properties and serum half-life, one preferred affibody molecule Z TNF-α 263 was redesigned to assemble drugs with bivalent TNFα binding with added specificity for serum albumin (Z TNF-α 263-ABD 035 -Z TNF-α 263, hereinafter denoted ZTAT). We further determined its binding ability, TNF-α signal blocking and neutralizing capacity, serum half-life and immunogenicity. Most importantly, our study provides strong evidence that the engineered ZTAT protein was therapeutically effective against KD induced-endothelial injury, as judged by both in vitro and in vivo assessments. These data suggested that because of the flexibility inherent, low-molecular weight anti-TNFα affibody construct ZTAT, can be developed into a potent therapeutic agent that can be produced and purified cost-effectively., Competing Interests: Declaration of competing interest All authors listed in the manuscript have read and agreed to its content and concurred with this submission. The manuscript submitted has not previously been published and is not under consideration for publication elsewhere. In addition, we declare that we have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: This study is to investigate whether angiotensin type 1 receptor blockers (ARBs) or angiotensin-converting enzyme inhibitors (ACEis) can regress coronary artery aneurysm (CAA) in patients with Kawasaki disease (KD)., Methods: This multicenter, prospective, observational study was conducted at 53 institutions throughout Japan. We enrolled patients who were diagnosed with KD after January 2015 and had a medium or large CAA (maximum luminal diameter ≥ 4 mm or z score ≥  + 5) 30 days or later after KD onset., Results: Of the 209 patients, 47 (22%) were taking ARBs/ ACEis. Compared with those in the non-ARB/ACEi group, the baseline CAA diameter was significantly greater (6.7 mm vs. 5.5 mm, p < 0.01), and bilateral CAA (70% vs. 59%, p = 0.01) and giant CAA (32% vs. 20%, p = 0.08) were more frequently observed in the ARB/ACEi group. Although the overall regression rates did not differ between the groups (67% vs. 65%), the regression rates of giant CAA were approximately 1.6 times greater in the ARB/ACEi group than in the non-ARB/ACEi group (36% vs. 23%). Multivariate Cox regression analysis after adjustment for other clinical variables suggested that ARBs/ACEis may be a factor in CAA regression (hazard ratio [HR]: 1.5, 95% confidence interval [CI]: 0.91-2.46)., Conclusions: Although ARBs/ ACEis were used more frequently in patients with severe CAA, these patients had similar CAA regression rates to patients not taking ARBs/ACEis. ARBs/ACEis may be beneficial agents aimed at inducing CAA regression in KD patients., What Is Known: • Large CAAs are less likely to regress and are always at risk of life-threatening cardiac events. • Moderate CAA, age less than 1 year, and female sex have been reported to be factors that promote the regression of CAA., What Is New: • Although ARBs/ACEis were used more frequently in patients with severe CAA, these patients had a similar rate of CAA regression to patients who did not take ARBs/ACEis. • The regression rates of giant CAA were approximately 1.6 times greater in the ARB/ACEi group than in the non-ARB/ACEi group., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: To determine the long-term outcomes among a cohort of patients with Kawasaki disease (KD) and a history of giant coronary artery aneurysms (CAAs) at a single US center., Study Design: Medical records for all patients with KD and giant CAAs at a pediatric academic institution were reviewed. Primary outcomes included major adverse cardiovascular events (MACE) and normalization of CA luminal diameter, using Kaplan-Meier analyses., Results: There were 60 patients with KD and giant CAAs identified between 1989 and 2023. The majority of patients were male (71.7%) with a median age at diagnosis of 0.9 years (range, 0.2-13.3 years). Patients were followed for a median of 11 years, up to 34.5 years. MACE occurred in 13 patients (21.7%) at a median of 1.4 years (range, 0.04-22.6 years) after KD diagnosis. The 10-, 20-, and 30-year MACE-free rates were 75%, 75%, and 60%. Patients with maximal CA z scores of ≥20 or bilateral CAA were more likely to have MACE. During follow-up, 26.7% of CAA regressed to a normal luminal diameter at a median of 3.6 years (range, 0.6-12.0 years). The 10-, 20- and 30-year likelihood of CA regression to normal luminal diameter was 36%, 46%, and 46%., Conclusions: Over 30 years, MACE occurred in nearly 22% of patients, more often in those with bilateral CAA or CA z scores of ≥20. Despite regression to a normal luminal diameter in >25% of CAAs, patients with a history of KD-associated giant CAA require ongoing surveillance for cardiac complications, even years after the initial disease., Competing Interests: Declaration of Competing Interest The authors declare no conflicts of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Adult Kawasaki patients may require intervention for occlusive coronary artery disease. Some adverse effects of first-generation drug-eluting stent implantation with sirolimus have been reported in this population., Methods: A total of nine lesions in eight (seven males, one female) patients who underwent stent implantations in this population between 2000 and 2021 were reviewed., Results: The age at stent implantation ranged from 31 to 47 years, with a median of 37 years. There were six lesions treated by primary percutaneous transluminal coronary interventions, and three by elective procedures. A coronary aneurysm was found in two lesions, and coronary artery calcification was found in all culprit lesions. The numbers of everolimus-eluting stents, sirolimus-eluting stents and bare metal stents were six, two, and one, respectively. As anti- thrombotic therapy, aspirin, clopidogrel, and prasugrel were given to four, three, and one, respectively. Warfarin was given to five patients. The follow-up ranged from 2 to 12 years, with a median of 4 years. Follow-up angiograms were performed for eight lesions, at 2 to 38 months, with a median of 11 months. The patency of the target vessel was confirmed in all eight vessels. Slight malapposition, and peri-stent contrast staining were found in two lesions each., Conclusion: Acute coronary syndrome due to coronary artery lesions caused by Kawasaki disease occurred, even in lesions without any apparent coronary artery aneurysms. In our study, we show safe and efficacious placement of second-generation stent without adverse effects during the short-term follow-up, but long-term follow-up is needed to determine the efficacy and complication.

Kawasaki Disease (KD) is a multisystemic vasculitis of medium- and small-sized arteries. Abnormal intimal thickening may develop in the involved arterial area after regression of coronary artery aneurysm (CAA). Intimal dysfunction may induce local stenosis or arteriosclerosis in the future. In this case-control study, we investigated 29 consecutive KD patients [20 male, median current age, 7.9 years; median follow-up duration, 5.7 years] and a group of 29 healthy matched controls (CON) [19 male, median current age, 10.8 years]. They were assesed and compared for CAA, LVFS, GCS, GLS, coronary artery (CA) Z scores, carotid intima-media thickness (IMT) and coronary artery IMT by high-resolution transthoracic echocardiography (hrTTE). Coronary artery IMT (caIMT) was significantly higher in patients with a maximal CA Z score > 2.5 in acute KD than in CON: KD caIMT: 0.62 mm [IQR, 0.57-0.72 mm] vs. 0.53 mm [0.51-0.60 mm], p = 0.043. CAAs were found in 15 (51.7%) patients with acute KD. The maximal median LCA Z score in acute KD was 2.57z [IQR, 1.93-3.2z] and in follow-up -0.39z [IQR, -1.25 to -0.36z]. There was no significant difference in carotid IMT between KD patients and CON. Signs of CA intima-media thickening were detected by hrTTE in patients with a maximal CA Z score > 2.5 in acute KD. These data indicate that these patients may be at risk for cardiovascular sequale even in the absence of permanent CA luminal abnormalities. Therefore long-term follow-up of this group of KD patients may be required., (© 2024. The Author(s).)

Introduction: Intravenous immunoglobulin (IVIG) plus methylprednisolone as initial intensive therapy or additional therapy in Kawasaki disease (KD) has been used in clinical practice. However, its molecular and cellular mechanism is unclear., Methods: We performed single-cell analysis on 14 peripheral blood mononuclear cell (PBMC) samples obtained from 7 KD patients who received either IVIG monotherapy or IVIG plus methylprednisolone therapy. This encompassed 4 samples from KD patients collected before and after IVIG treatment, as well as 3 samples from KD patients before and after IVIG plus methylprednisolone therapy., Results: Both IVIG monotherapy and IVIG plus methylprednisolone therapy can increase lymphocyte counts (e.g. CD4+T, CD8+T, and gdT cells) to address lymphopenia. They can also decrease monocyte counts and repress the expression of S100A12, NLRP3, and genes associated with immune-cell migration in monocytes. IVIG combined with methylprednisolone downregulates more monocyte-driven inflammatory pathways than IVIG alone. Additionally, this combination uniquely enhances NK cell cytotoxicity by modulating receptor homeostasis, while significantly upregulating interferon-related genes in CD4+ T cells, CD8+ T cells, and B cells, particularly type I interferons., Conclusion: The combination of IVIG with methylprednisolone attenuated monocyte-driven inflammation and improved NK cell cytotoxicity which might provide clues for pediatricians to consider treatment options for children with KD. Whether the monocyte-driven hyperinflammatory state and NK cell function can be indicators for the clinical choice of IVIG with methylprednisolone therapy in KD needs further investigation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Yang, Chen, Feng, Zhang, Wang, Zheng and Li.)

Background: Primary adjunctive therapy with corticosteroids have been shown to reduce coronary artery abnormalities in high-risk Kawasaki Disease (KD) patients in Japan (RAISE study). We evaluated their effect on outcomes in North American patients with high-risk KD., Methods: We performed a single-center retrospective review of high-risk KD patients between 2010 - 2023. From 2017-2023, adjunctive corticosteroids in a modified RAISE regimen (mRAISE) were given to high-risk patients as primary adjunctive therapy with intravenous gammaglobulin (IVIG) and aspirin. We compared CA outcomes in these patients and those presenting from 2010-2016, when mRAISE therapy was not administered., Results: A total of 221 high-risk KD patients were treated at our institution between 2010-2023. Among these, 83 received the mRAISE regimen and 138 did not (no corticosteroid, n=82, corticosteroid in a non-mRAISE regimen, n=56). There were no significant differences in coronary artery outcomes in the mRAISE and non-mRAISE groups. Patients receiving the mRAISE regimen were significantly less likely to receive more than one dose of IVIG when compared to those who did not receive this regimen (11% vs 33%, p<0.001)., Conclusion: Use of adjunctive primary therapy with corticosteroids in a mRAISE regimen in high-risk KD patients resulted in significantly decreased IVIG retreatment., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Journal of the Pediatric Infectious Diseases Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Kawasaki Disease (KD) is self-limited vasculitis, the main consequence of which may be involvement of the coronary arteries, especially in patients without treatment. It is estimated that coronary artery aneurysms occur in 15% to 25% of untreated children. Patients with coronary aneurysms may remain asymptomatic for years. The first symptom may be life-threatening sudden cardiac arrest or myocardial ischaemia. Methods: We report a case of a 17-year-old boy with an insignificant past medical history who presented with sudden cardiac arrest. Results: During diagnostics, channelopathies, structural heart defects, drug abuse, and myocardial infarction were excluded. The patient underwent coronary angiography, confirmed by CT angiogram of the coronary vessels, which revealed most likely ruptured, clotted, well-calcified aneurysm of the left anterior descending artery (LAD) with collateral circulation, probably a consequence of untreated Kawasaki disease in early childhood. Conclusions: Complications of KD should be considered in the differential diagnosis of sudden cardiac arrest, especially in a young person., Competing Interests: The authors declare no conflicts of interest.

Background: Kawasaki disease (KD) is an acute systemic vasculitis that can lead to acquired heart disease in children mostly from in developed countries. The previous research showed that B cells in KD patients underwent a profound change in both the cell numbers and types after intravenous immunoglobulin (IVIG) therapy., Methods: We performed the single-cell RNA-sequencing for the peripheral blood mononuclear cells (PBMCs) from three febrile patients and three KD patients to investigate the possible mechanism underlying B cell developmental dysfunction in KD. The pseudo-time analysis was employed to study the developmental trajectories of the PBMCs in febrile control and KD patients., Results: Overall single-cell expression profiles show that the biological processes of immunity, B cell activation pathway and their related biological entities are repressed in KD patients before IVIG treatment compared to febrile patient and KD patients after IVIG treatment. The differentially expressed gene analyses further demonstrate that B cell signaling pathway is downregulated in B cells and plasma blast cells of KD patients before treatment while cell cycle genes and MYC gene are upregulated in dendritic cells (DCs) and hematopoietic stem and progenitor cells (HSPCs) of KD patients before treatment. The biological process of immune response is upregulated in the HSPCs of KD patients before treatment in our dataset while the biological process of inflammatory response is upregulated in the HSPCs of KD patients before treatment in GSE168732 dataset. Single-cell trajectory analyses demonstrate that KD patients before treatment have a shortened developmental path in which B cells and T cells are failed to differentiate into separate lineages. HSPD1 and HSPE1 genes show an elevated expression level in the early cell development stage of KD patients before treatment accompanied with the repression of MYC, SPI1, MT2A and UBE2C genes. Our analyses of all B cells from KD patients before treatment show most of B cells are arrested in a transitional state with an ill developmental path compared with febrile patients and KD patients after treatment., Conclusion: Our results indicate that the immune premature HSPCs accompanied with the abnormal expression dynamics of cell cycle and SPI1 genes are the mechanism underlying B cell developmental dysfunction in KD patients., Competing Interests: Author GL was employed by the company Daozhi Precision Medicine Technology Shanghai Co., LTD. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Lin, Wang, Ding, Li, Chen, Qiu, Song, Liu, Jiang, Huang, Shen, Xiao and Xie.)

Background: Kawasaki disease is an acute febrile disease causing systemic vasculitis that is common in infants and young children. This study was conducted to explore the relationships of the rs1412125, and rs2249825 single nucleotide polymorphisms of the high mobility group box 1 gene to Kawasaki disease and its complication of coronary artery injury., Methods: In total, 200 children with Kawasaki disease (49 with coronary artery injury) and 200 healthy controls were enrolled in this study. Polymerase chain reaction was used to amplify the target gene, and direct sequencing was performed to determine distributions at the rs1412125 T/C and rs2249825 C/G loci in the HMGB1 gene. The chi-squared test was used to compare data between groups. Linkage disequilibrium coefficients and single nucleotide polymorphism haplotype analysis were conducted, and a false-positive report probability analysis was used to assess significant associations. Expression quantitative trait loci analysis was performed to determine if single nucleotide polymorphisms affected mRNA levels via the GTEx portal., Results: Significant differences in the genotype TT, TC, and CC distributions ( χ 2 = 7.918, P = 0.019) and allele T and C frequencies ( χ = 0.013) of rs1412125 T/C locus were found between the Kawasaki disease and healthy control groups. The genotype CC was associated with a greater Kawasaki disease risk [odds ratio = 3.205, 95% confidence interval = 1.352-7.595, 2 = 6.125, P = 0.006]. C allele carriers had a higher Kawasaki disease risk than did T allele carriers (odds ratio = 1.469, 95% confidence interval = 1.083-1.993, χ 2 = 7.560, P = 0.006]. C allele carriers had a higher Kawasaki disease risk than did T allele carriers (odds ratio = 1.469, 95% confidence interval = 1.083-1.993, χ 2 = 6.125, P = 0.013). The rs1412125 genotype T/C distribution ( χ 2 = 0.001). No significant difference in the rs2249825 genotype C/G distribution or allele frequencies was found between the Kawasaki disease and control groups, or between the coronary artery injury and without coronary artery injury groups.P = 0.004) and allele frequencies ( χ 2 = 8.813, P = 0.003) differed significantly between patients with and without coronary artery injury. In the dominant model, the coronary artery injury risk was 3.006 times greater for patients with the TT genotype than for those with the other genotypes (odds ratio = 3.006, 95% confidence interval = 1.540-5.867, χ 2 = 10.875, P = 0.001). No significant difference in the rs2249825 genotype C/G distribution or allele frequencies was found between the Kawasaki disease and control groups, or between the coronary artery injury and without coronary artery injury groups., Conclusions: The rs1412125 polymorphism of the HMGB1 gene is associated with Kawasaki disease and its coronary artery injury complication. The CC genotype may be a risk factor for Kawasaki disease onset, and the TT genotype may be a risk factor for coronary artery injury in Kawasaki disease.

Objectives: To study the composition, abundance, and functional profiles of the intestinal microbiota in infants and young children with Kawasaki disease (KD) during the acute phase, and to explore the potential role of intestinal microbiota in the pathogenesis of KD., Methods: Six children aged 0-3 years with acute KD admitted to the Department of Cardiology, Children's Hospital Affiliated to Capital Institute of Pediatrics from July to October 2021 were prospectively included as the KD group. Six age- and sex-matched healthy children who underwent physical examinations at the hospital during the same period were selected as the healthy control group. Metagenomics sequencing was used to detect and compare the differences in the microflora structure and functional profiles of fecal samples between the two groups., Results: There were significant differences in the structural composition and diversity of intestinal microbiota between the two groups ( P <0.05). Compared with the healthy control group, the abundance of Listeria &#95; monocytogenes (family Listeriaceae and genus Listeria ), Bifidobacterium &#95; rousetti , Enterococcus &#95; avium , and Enterococcus &#95; hirae was significantly higher in the intestinal microbiota in the KD group ( | LDA | >2.0, P <0.05). The steroid degradation and apoptosis pathways were significantly upregulated in the KD group compared with the healthy control group, while the Bacterial&#95;secretion&#95;system, Sulfur&#95;metabolism, Butanoate&#95;metabolism, Benzoate&#95;degradation, β-alanine metabolism, and α-linolenic acid pathways were significantly downregulated (|LDA|>2, P <0.05)., Conclusions: There are significant differences in the structure and diversity of intestinal microbiota between children aged 0-3 years with acute KD and healthy children, suggesting that disturbances in intestinal microbiota occur during the acute phase of KD. In particular, Listeria &#95; monocytogenes , Enterococcus &#95; avium , and Enterococcus &#95; hirae may be involved in the pathogenesis of KD through steroid degradation and apoptosis pathways.

A 37-year-old man with a history of Kawasaki disease presented with total occlusion of the right coronary artery. The patient underwent percutaneous coronary intervention (PCI) with excimer laser coronary angioplasty (ELCA) and plain old balloon angioplasty (POBA). Three months after PCI, a coronary aneurysm with restenosis was detected at the PCI site, and PCI was performed again using a small balloon. The aneurysm healed three months after the second PCI procedure. This is the first report describing the long-term outcome after an aneurysm caused by PCI with ELCA and POBA.

Background: Kawasaki disease (KD) is a kind of pediatric vasculitis, whose pathogenesis has not been elucidated until now. Many scholars believe that KD is one type of infectious diseases in the susceptible groups. However, no recognized pathogens are confirmed. Human cytomegalovirus (HCMV) is a ubiquitous human herpes virus, which can infect varieties of cells including endothelial cells. Studies reported that the viral protein pUL135 is very important for virus replication, reactivation and immune escape. Therefore, we hypothesize that HCMV pUL135 may have a pathogenic effect on KD., Methods: We first determined pUL135 levels in the serum from KD patients. Next, we examined the effects and mechanisms of pUL135 on endothelial cell proliferation and migration. Finally, we assessed the effect of pUL135 on cardiac inflammation in a KD murine model., Results: Data showed that pUL135 level was significantly increased in the serum from KD patients compared with the healthy and fever controls. And pUL135 expression in endothelial cells remarkably inhibited cell proliferation, migration and tube formation. Moreover, expression of pUL135 obviously affected actin cytoskeleton. Mechanism investigation substantiated that pUL135 mediated endothelial cell dysfunction via regulating CD2AP. Ultimately, we found that HCMV pUL135 aggravated coronary arteritis in the Candida albicans cell wall extracts (CAWS)-induced KD mouse model., Conclusion: Our findings imply that HCMV pUL135-mediated endothelial dysfunction plays an important role in exacerbating coronary artery injury in KD conditions., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Kawasaki disease (KD) is a significant cause of acquired heart disease in children, particularly in developed countries. Incomplete Kawasaki disease (IKD) lacks some of the classic KD symptoms, complicating diagnosis. This study explores the potential role of anterior uveitis (AU) as a diagnostic marker for IKD and its possible association with reducing the incidence of coronary artery lesions (CALs)., Methods: A retrospective review of medical records was conducted on 111 pediatric patients diagnosed with IKD at two tertiary care centers between January 2018 and December 2023. The cohort consisted of 33 patients with AU and 78 without AU. The AU group had a mean age of 4.1 years, while the non-AU group had a mean age of 4.5 years. AU was present in 30% of cases. The study primarily focused on the time to diagnosis, incidence of CALs, and the independent association of AU with CALs using multivariate logistic regression analysis., Results: Patients with AU were diagnosed and treated earlier, with a mean time to diagnosis of 5.1 days compared to 7.4 days in the non-AU group. Additionally, the incidence of CALs was significantly lower in the AU group (4.4%) compared to the non-AU group (31.8%, p < 0.001). Multivariate analysis revealed that AU was independently associated with a significantly reduced risk of CALs (OR = 0.066, 95% CI = 0.009-0.494, P = 0.008)., Conclusions: This study suggests that AU may be associated with earlier diagnosis and treatment of IKD, potentially lowering the risk of CALs. While AU shows promise as a diagnostic marker, further prospective studies are needed to validate these findings and determine whether AU should be integrated into clinical guidelines for earlier detection of IKD and improved patient outcomes., (© 2024. The Author(s).)

Background: To explore the application value of syndecan-1 (SDC-1) in the diagnosis of coronary artery lesions (CALs) in Kawasaki disease (KD) patients and the correlation of multiple laboratory indicators in KD patients., Methods: 86 pediatric Kawasaki disease (KD) patients and 52 healthy controls admitted from January 2018 to December 2023 were retrospectively analyzed. Venous blood samples from KD patients were analyzed for white blood cells (WBC), platelets (PLT), C-reactive protein (CRP), interleukin-6 (IL-6), syndecan-1 (SDC-1), coagulation parameters, and lipid profiles. Correlations between these laboratory indicators were assessed. Receiver operating characteristic (ROC) curve analysis determined the diagnostic value of SDC-1 for coronary artery lesions (CALs) in KD patients. SDC-1 levels were further compared across different CAL severity groups., Results: The levels of ALT, AST, WBC, PLT, CRP, IL-6, and SDC-1 in the KD group were significantly higher than those in the control group (P < 0.05). Coagulation function analysis showed that APTT, TT and FIB levels were significantly increased in the KD group compared with the control group (P < 0.05). Lipid profile analysis revealed that TC, HDL-C, and ApoA1 were significantly decreased, whereas TG, LDL-C, and ApoB100 were significantly increased in the KD group (P < 0.05). Refractory KD patients exhibited significantly higher levels of ALT, AST, SDC-1, CRP, WBC, and TG compared to responsive KD patients (P < 0.05). Correlation analysis indicated a strong positive correlation between PLT and LDL-C (r = 0.227, P = 0.035) and between IL-6 and TG (r = 0.491, P = 0.000), while CRP was negatively correlated with ApoA1 (r = -0.265, P = 0.014). Among the 86 KD patients, 41 (47.67%) developed CALs, with 19 classified as mild, 15 as moderate, and 7 as severe. For predicting CALs among KD patients, the threshold of SDC-1 was identified as 5.5 ng/ml, with a sensitivity of 70.7%, specificity of 64.4%, positive predictive value of 65.91%, negative predictive value of 69.05%, and an AUC of 0.762 (95% confidence interval 0.662-0.861, P < 0.001). SDC-1 levels significantly differed among the CAL severity groups (P = 0.008), with higher levels observed in moderate compared to mild CALs, and in severe compared to moderate CALs., Conclusion: In conclusion, SDC-1 has strong clinical value in the diagnosis of CALs in KD patients, and there is a close relationship between the levels of inflammatory factors, coagulation function and lipid levels in KD patients., (© 2024. The Author(s).)

Background: Kawasaki disease (KD) is a medium artery vasculitis that predominantly affects children under age 5. Prompt diagnosis and treatment with IVIG and moderate dose aspirin is required to prevent the formation of coronary artery aneurysms. While scrotal edema and erythema have been seen in KD, here we present a distinctive case of incomplete Kawasaki with these features as well as penile edema., Case Presentation: A 2-year-old, unvaccinated, African American male presented with 4 days of fever, bilateral limbic sparing conjunctivitis, a papular rash, unilateral shotty cervical lymphadenopathy, mild right-hand edema, and scrotal and penile edema and erythema. His labs were significant for sterile pyuria, elevated ALT, anemia for age, and hypoalbuminemia. He was diagnosed with incomplete Kawasaki disease and was treated with IVIG and moderate dose aspirin. Echocardiogram was negative for coronary aneurysms. His symptoms resolved and he was discharged home with low dose aspirin. At his 2-week follow up, he remained well-appearing with no refractory Kawasaki symptoms., Conclusion: This is a unique case of penile edema in KD which to our knowledge has not been previously reported in literature. An understanding of genitourinary symptoms in Kawasaki disease can help timely diagnosis and treatment of the disease., (© 2024. The Author(s).)

Background: Kawasaki disease is a rare systemic inflammatory syndrome that mainly affects children under five years of age and is the first cause of pediatric acquired cardiovascular disease. The pathogenesis is complex and a viral trigger is suspected, as well as genetic susceptibility. Multiple studies around the world have shown a decrease in the incidence of Kawasaki disease and have hypothesized that the different sanitary measures enforced in each country during the pandemic period could be responsible to a certain extent. The aim of this study is to evaluate the effects of the COVID-19 pandemic on the disease's incidence, defining characteristics, coronary artery outcomes and management in a tertiary center in Switzerland., Methods: This study is a retrospective analysis of children who have been diagnosed with Kawasaki disease that compares clinical, laboratory, SARS-CoV-2 exposure, and echocardiographic data as well as treatments before (January 1st 2017 to February 24th 2020) and during (February 25th 2020 to December 31st 2022) the COVID-19 pandemic in Switzerland. Statistical significance of differences in the compared parameters was assessed., Results: Of the 90 patients included, 31 belonged to the first group and 59 belonged to the second group. There was a statistically significant (p < 0.05) increase in incidence during the pandemic period (5.91/100,000 children) of 88% compared to the pre-pandemic period (3.14/100,000 children). A lesser seasonal variation was observed during the pandemic. 30% of the patients in the pandemic group had an exposure to SARS-CoV-2. There was no other notable difference in demographic factors, clinical presentation, coronary outcome or administered treatment., Conclusions: To the best of our knowledge, this is the first prolonged European study comparing Kawasaki disease before and during the COVID-19 pandemic. There was a significant increase in incidence in Kawasaki disease during the COVID-19 pandemic. In contrast, studies done in Japan, South Korea and the USA have shown a decrease in incidence. Differences in methodologies, genetics, ethnicities, environments, microbiome-altering behaviors, sanitary measures and SARS-CoV-2 spread are factors that should be considered. Further studies analyzing the differences between countries with increased incidence of Kawasaki disease could help better understand the relevance of such factors and provide more insight into the etiologies of this particular disease., (© 2024. The Author(s).)

Introduction: Kawasaki disease (KD), a common cause of acquired heart disease in children in developed countries, is primarily treated with intravenous immunoglobulin (IVIG), but some children demonstrate IVIG resistance with increased coronary artery injury risk. T cells have been demonstrated to be involved in the pathogenesis of KD and its treatment with IVIG. However, the role and mechanism of dual TCR T lymphocytes in the occurrence of KD and IVIG therapy remain unclear., Methods: This study, based on scRNA-seq combined with TCR-seq technology, clustered the peripheral blood mononuclear cells of 3 healthy controls and 6 KD patients before and after IVIG treatment. Comparative analysis was conducted to investigate the differences in the proportion of single/dual receptor T cells, the characteristics of CDR3 repertoires, cell types, and the expression of transcription factors among the three groups. The study aimed to explore the correlation between dual TCR T cells and KD as well as IVIG treatment., Results: In our experimental results, we observed the presence of dual TCR T cells in all three groups. However, compared to the healthy control group and the IVIG-treated group, the KD patients before IVIG treatment exhibited a lower proportion of dual TCR T cells, with variability between samples, ranging from 4% to 15%. Notably, after IVIG treatment, the proportion of dual TCR T cells significantly increased, stabilizing above 12%, and these T cells also exhibited clonal expansion and a preference for V gene usage. In addition we found differences in dual TCR T cell subsets among the three groups, for example, IVIG treatment increases the proportion of dual TCR Treg cells, but it still remains below that of healthy control groups, significantly higher proportions of both dual TCR CD8 central and effector memory T cells in IVIG-treated KD patients, and differences in the expression of transcription factors between single and dual TCR T cells. These results suggest dual TCR T cells correlate with KD and IVIG treatment., Conclusion: Dual TCR T lymphocytes, especially dual TCR CD8 T cells and Treg cells, play crucial roles in the pathogenesis of KD and during IVIG treatment, providing strong support for further elucidating KD pathogenesis and optimizing treatment strategies., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Xu, Yuan, Mou, Hui, Zhang, Yao and Li.)