Kawasaki disease and the environment: an enigmatic interplay

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.

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.