Kawasaki disease and the environment: an enigmatic interplay

Long-term risk of allergic disorders following Kawasaki disease: a population-based cohort study

BACKGROUND

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting children under five years old. While its etiology remains unclear, immune dysregulation has been implicated, suggesting a potential link between KD and allergic diseases. Previous epidemiological studies have reported inconsistent findings regarding this association across different countries. This study aims to investigate the association between KD and allergic diseases in Korea.

METHODS

A nationwide population-based cohort study was conducted utilizing data from the Korean National Health Insurance database. KD cases were defined as admissions with a primary diagnosis of KD plus treatment records for immunoglobulin or aspirin. The control group had no KD diagnosis. Between 2008 and 2015, 41,806 KD cases were matched 1:4 with 163,548 controls using propensity score matching. The incidence and prevalence of asthma, rhinitis, atopic dermatitis, and urticaria from 2017 to 2021 were analyzed using hazard ratios (HRs) and odds ratios (ORs).

RESULTS

Mean age was 2.63 ± 1.84 years for KD patients and 2.64 ± 1.85 years for controls (P = 0.119). The proportion of females was 42.20% in the KD group and 42.60% in the control group (P = 0.145). KD patients showed significantly higher risks for developing rhinitis (HR 1.045, 95%CI 1.013-1.078) and urticaria (HR 1.139, 95%CI 1.085-1.197). However, no significant association was found in the incidence of asthma or atopic dermatitis. KD diagnosis at age 5 or older was associated with decreased risk of all allergic disorders. The prevalence of all allergic disorders studied was significantly higher in the KD group, with the strongest associations observed for rhinitis (OR 1.178, 95%CI 1.151-1.205) and urticaria (OR 1.192, 95%CI 1.155-1.230). Gender and urban living also influenced the prevalence of allergic disorders. A sensitivity analysis conducted to account for the COVID-19 pandemic showed consistent results, confirming the association between KD and increased risk and prevalence of allergic disorders.

CONCLUSIONS

This study demonstrates a significant association between Kawasaki disease and increased risk of allergic disorders, particularly rhinitis and urticaria. These findings suggest potential shared pathogenesis between the two conditions and highlight the need for long-term monitoring of allergic conditions in KD patients.

CLINICAL TRIAL NUMBER

Not applicable.

Circulating Inflammatory Factors and Bidirectional Mendelian Randomization Analysis in Patients with Kawasaki Disease

Background

Kawasaki disease (KD), also known as mucocutaneous lymph node syndrome, is a systemic immune vasculitis with an unclear etiology. It is often complicated by coronary artery disease. This study uses bidirectional Mendelian randomization (MR) to investigate the interaction between KD and circulating inflammatory factors, providing insights into their causal relationships.

Methods

We conducted a two-way pooled MR analysis to examine the causal links between 41 circulating inflammatory regulators and the risk of KD. Genetic data related to inflammation were sourced from three genome-wide association studies (GWASs) involving CRP, PCT, and cytokines, while KD data were derived from other studies. Inverse-variance weighting (IVW) was the primary MR method, with sensitivity analyses performed using MR‒Egger, weighted median, weighted mode, and MR-PRESSO to ensure robustness.

Results

Forward MR analyses showed no significant relationship between inflammatory factors and KD outcomes. In contrast, reverse MR, with KD as the exposure factor, revealed that interleukin-2 (IL-2) and interleukin-8 (IL-8) were significantly associated with KD (IL-2: OR=1.0085, P=0.037; IL-8: OR=1.0099, P=0.014). Borderline significant associations were observed for factors such as B_NGF, EOTAXIN, HGF, and IL_12_P70 in MR‒Egger and weighted median analyses.

Conclusion

This bidirectional MR study highlights the role of circulating inflammatory modulators in KD risk, offering insights into KD pathogenesis and potential therapeutic targets.

Unveiling the anti-inflammatory mechanism of exogenous hydrogen sulfide in Kawasaki disease based on network pharmacology and experimental validation

Kawasaki disease (KD) is a severe pediatric vasculitis leading to coronary artery complications. Hydrogen sulfide (H2S), a recognized endogenous gasotransmitter with anti-inflammatory properties, offers potential as a novel treatment for KD through its cardiovascular benefits. However, the specific effects and underlying mechanisms remain unclear. The objective of present study is to investigate the anti-inflammatory and therapeutic effects of exogenous H2S in KD using network pharmacology and experimental validation. By online database searches, a total of 405 pharmacological targets for H2S, 826 KD-related targets, and 107 potential therapeutic targets of H2S for KD were identified. Through PPI analysis and Cytoscape screening, 9 hub genes were filtered, namely TNF, IL6, JUN, AKT1, IL1B, TP53, NFKB1, MAPK1, and RELA. KEGG pathway enrichment indicated that the TLR4/MyD88/NF-κB signaling pathway may play a crucial role in the therapeutic effects of H2S on KD. Additionally, in vivo experiments confirmed that the treatment of sodium hydrosulfide (NaHS), an H2S donor, markedly improved body weight, reduced inflammatory pathology in the coronary arteries, and downregulated levels of inflammatory cytokines TNF-α, IL-1β, and IL-6. Furthermore, WB analysis confirmed that NaHS inhibited the expression of TLR4, MyD88, NF-κB, and p-NF-κB. In brief, it is the first to reveal that exogenous H2S attenuates the inflammatory response in KD via the TLR4/MyD88/NF-κB pathway, highlighting its potential as a novel therapeutic approach for KD. These findings lay a foundation for further development of H2S-based therapies for KD management.

Genome Analysis of Japanese Yersinia pseudotuberculosis Strains Isolated From Kawasaki Disease Patients and Other Sources and Their Phylogenetic Positions in the Global Y. pseudotuberculosis Population

Yersinia pseudotuberculosis (Ypt) is a gram-negative bacterium that infects both humans and animals primarily through fecal‒oral transmission. While Ypt causes acute gastroenteritis in humans, an association with Kawasaki disease (KD), a disease that primarily affects infants and young children and causes multisystemic vasculitis, has also been suspected. Although KD represents a significant health concern worldwide, the highest annual incidence rate is reported in Japan. Previously, a geographical origin-dependent population structure of Ypt comprising the Asian, transitional, and European clades was proposed. However, genomic data on KD-associated Ypt strains is currently unavailable. In this study, to analyze the phylogenetic and genomic features of KD-associated strains, we determined the whole-genome sequences of 35 Japanese Ypt strains, including 11 KD-associated strains, and constructed a genome set (n = 204) representing the global population of Ypt by adding publicly available Ypt genomes. In a phylogenetic analysis, all sequenced Japanese strains, including the KD-associated strains, belonged to the Asian clade, which appeared to be the ancestral clade of Ypt, and the KD-associated strains belonged to multiple lineages in this clade. Strains from patients with Far East scarlet-like fever (FESLF), a KD-related disease, also belonged to the Asian clade. Moreover, no KD strain-specific genes were identified in pan-genome-wide association study analyses. Notably, however, the gene encoding a superantigen called Yersinia pseudotuberculosis-derived mitogen (YPM) showed a distribution pattern highly biased to the Asian clade. Although further studies are needed, our results suggest that Asian clade strains may have a greater potential to trigger KD.

Proteomic insights into molecular alterations associated with Kawasaki disease in children

BACKGROUND

Kawasaki disease (KD) is a pediatric vasculitis that can lead to coronary artery complications if not promptly diagnosed. Its nonspecific early symptoms, primarily fever, often result in misdiagnosis. This study aimed to identify potential biomarkers for early KD diagnosis using proteomic analysis of blood samples.

METHODS

Serum samples were collected from three groups: children with acute KD (n = 20, CQB group), age-matched febrile children with bacterial infections (n = 20, C group), and children recovered from KD (n = 8, CQBC group). Proteomic analysis was performed to identify differentially expressed proteins in serum specimens, followed by functional and pathway enrichment analysis.

RESULTS

Compared to controls, 92 proteins were upregulated and 101 were downregulated in acute KD, with significant enrichment in the AMPK pathway. In recovered KD, 537 proteins were upregulated and 231 downregulated, predominantly affecting the PI3K-Akt pathway. A total of 56 proteins showed contrasting expression patterns between acute and recovery phases, implicating the complement and coagulation cascades. Notably, complement component 6 (C6), complement component 3 (C3), and α1-antitrypsin (A1AT) emerged as potential biomarkers involved in KD progression and recovery.

CONCLUSIONS

C6, C3, and A1AT may serve as novel biomarkers for early KD diagnosis and monitoring. These findings provide new insights into KD pathogenesis and potential targets for clinical application.

Urinary exosomal microRNA-200 family: diagnostic biomarkers for Kawasaki disease and their link to inflammatory markers

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.

Development of a liquid chromatography-mass spectrometry based targeted metabolomics method for discovering diagnostic biomarkers in Kawasaki disease

Kawasaki disease (KD) has emerged as the leading cause of acquired heart disease in children, primarily due to the absence of highly sensitive and specific biomarkers for early and accurate diagnosis. To address this issue, a simple and comprehensive targeted metabolomics method employing ultra high-performance liquid chromatography coupled with Q-TRAP mass spectrometry has been developed to identify new metabolite biomarkers for KD. This method enables the simultaneous quantification of 276 metabolites, covering 60 metabolic pathways, with a particular emphasis on metabolites relevant to KD. The use of nine ISs and commercial quality control samples significantly enhances both accuracy and precision. Through validation and application to serum samples from patients with KD, seventeen differential serum metabolites were identified. The altered metabolites are primarily associated with three functional metabolic pathways: tricarboxylic acid cycle, tryptophan metabolism, and bile acid metabolism, all of which are believed to be involved in the inflammatory and immune responses in KD patients. Ultimately, eight differential metabolites (indole-3-propionic acid, thiamine, indolepyruvic acid, levodopa, l-selenomethionine, isocitric acid, trans-aconitate, and N-acetylasparagine) were identified that could potentially serve as diagnostic biomarkers with the area under the curve values exceeding 0.9. Our targeted metabolomics approach demonstrates applicability in identifying potential metabolite biomarkers for KD and holds great promise in unraveling the intricate pathophysiology of the disease.

Utilizing T-Lymphocyte Activation-Related Cytokines to Predict Non-Responsiveness to Treatment in Pediatric Kawasaki Disease

Objective

To investigate the predictive value of T-lymphocyte activation-related cytokines in non-responsive Kawasaki disease.

Methods

Eighty-two children with Kawasaki disease, hospitalized from June 2022 to December 2023, were divided into two groups based on treatment response: the sensitive Kawasaki disease group (n=71) and the non-responsive Kawasaki disease group (n=11). Serum levels of T-lymph activation-related cytokines, including interleukin-2, 6, 7, 12, 15, 17, and tumor necrosis factor alpha, were measured before and after IVIG treatment in both groups. The differences in cytokine levels between the two groups were compared pre- and post-treatment. The ability of these cytokines to discriminate non-responsive Kawasaki disease was evaluated using ROC curves to determine the cut-off value.

Results

Before initial treatment, IL-2, IL-6, IL-7, IL-12, IL-15, IL-17, and tumor necrosis factor-α values were significantly higher in the non-responsive Kawasaki disease group compared to the sensitive Kawasaki disease group. Comparisons before and after initial treatment showed significant decreases in IL-6 and 17 in the sensitive Kawasaki disease group and significant decreases in IL-6 and 7 in the non-responsive Kawasaki disease group. IL-6 and 17 significantly increased in the sensitive group compared to the non-responsive group after initial treatment. The ROC curves indicated that IL-6 predicted the area under the curve (AUC) for non-responsive Kawasaki disease to be 0.859 before treatment and 0.920 after treatment. Similarly, IL-17 had AUC values of 0.699 before treatment and 0.884 after treatment.

Conclusion

Reassessing IL-6 and IL-17 following the initial treatment for Kawasaki disease may improve early warning signals for unresponsive Kawasaki disease.

Dengue Mimickers: Which Clinical Conditions Can Resemble Dengue Fever?

Epidemics and outbreaks caused by the dengue virus pose risks to populations and have high mortality rates, causing burdens and economic costs worldwide. Brazil recently experienced an explosive increase in the number of dengue cases and fatalities. Dengue is an acute febrile illness that can progress to severe forms. It affects more than 100 countries, presenting ongoing challenges in Brazil and globally since its identification. Other conditions may be overlooked or mistaken for dengue. The most important differential diagnoses are other infectious diseases and rheumatological, hematological, gastroenterological, and neurological disorders. In this article, we discuss the primary differential diagnoses of dengue and offer a literature review highlighting the key clinical differences among clinicians. This review emphasizes the critical importance of differentiating dengue fever from infectious diseases such as meningococcemia and malaria and autoimmune and rheumatological conditions such as systemic lupus erythematosus to ensure timely and appropriate management.

Lymphocyte-C-reactive protein ratio combined with albumin upon admission predicts coronary artery dilation and aneurysm formation in pediatric patients with Kawasaki disease: a retrospective cohort study

BACKGROUND

We aimed to explore simple and effective clinical parameters or combinations to predict coronary artery dilation and aneurysm formation in pediatric patients with Kawasaki disease (KD).

DESIGN AND METHODS

This retrospective cohort study included pediatric patients with KD from January, 2013 to December, 2022. Multiple demographic and clinical data were collected, collated, and calculated from the medical records. Then they were divided into the coronary artery dilation and aneurysm formation group or the non-coronary artery dilation and aneurysm formation group. Lymphocyte-C-reactive protein ratio (LCR) was transformed into its natural logarithm and expressed as lnLCR.

RESULTS

A total of 64 pediatric patients with KD were enrolled in this cohort study after 1:3 propensity score matching (PSM). For each unit increase in lnLCR, the possibility of coronary artery dilation and aneurysm formation decreased to 0.419 times the original value. The areas under the receiver operating characteristic (ROC) curves of lnLCR combined with albumin (ALB), ALB, and lnLCR to classify pediatric patients with KD into the coronary artery dilation and aneurysm formation group were 0.781, 0.692, and 0.743, respectively.

CONCLUSION

LCR combined with ALB upon admission is a promising predictor of coronary artery dilation and aneurysm formation in pediatric patients with KD.

Mycoplasma pneumoniae-induced Kawasaki disease via PINK1/Parkin-mediated mitophagy

Kawasaki disease (KD) is a systemic vasculitis with an unknown cause that primarily affects children. The objective of this study was to explore the function and underlying mechanism of mitophagy in Mycoplasma pneumoniae (MP)-induced KD. To create MP-induced KD models, Human coronary endothelial cells (HCAECs) and DBA/2 mice were employed and treated with Mp-Lipid-associated membrane proteins （LAMPs）. Lactate dehydrogenase (LDH) levels were tested to determine cellular damage or death. The inflammatory cytokines tumor necrosis factor (TNF)--α and interleukin (IL)-6 were measured using the Enzyme-Linked Immunosorbent Assay (ELISA) method. RT-qPCR and Western blotting were used to determine the expression of Intercellular Adhesion Molecule(ICAM)-1, vascular cell adhesion molecule (VCAM)-1, inducible nitric oxide synthase(iNOS), LC3, p62, PINK1(a mitochondrial serine/threonine-protein kinase), and PARKIN(a cytosolic E3-ubiquitin ligase). The adenosine triphosphate （ATP）, reactive oxygen species （ROS）, and mitochondrial membrane potential（MMP） levels were measured to determine mitochondrial function. Mitophagy was investigated using immunofluorescence and a mitophagy detection test. Autophagosome and mitochondrial morphology were examined using transmission electron microscopy. To identify inflammatory cell infiltration, hematoxylin and eosin staining was utilized. Mp-LAMPs increased the levels of TNF-α, IL-6, ICAM-1, VCAM-1, and iNOS in an HCAEC cell model, along with LDH release. After Mp-LAMPs exposure, there was a rise in LC3 and a reduction in p62. Meanwhile, the expression of PINK1 and Parkin was increased. Cyclosporin A dramatically increased ATP synthesis and MMP in HCAEC cells treated with Mp-LAMPs, while suppressing ROS generation, demonstrating excessive mitophagy-related mitochondrial dysfunction. Additionally, neither body weight nor artery tissue were affected due to PINK1 and Parkin suppression Cyclosporin A in Mp-LAMPs-treated mice. These findings indicated that PINK1/Parkin-mediated mitophagy inhibition may be a therapeutic target for MP-induced KD.

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.