The recent document from the American Heart Association updates the guidelines on the diagnosis and management of Kawasaki disease (KD), a severe acute systemic inflammatory and febrile illness with mucocutaneous manifestations and lymph node involvement primarily affecting children under 5 years of age. Coronary artery involvement, with dilation and aneurysms in approximately 25% of patients, and cardiovascular system involvement make KD the most common systemic vasculitides and the leading cause of acquired heart disease in pre-school children living in developed countries. Classic KD is diagnosed based on established clinical and laboratory criteria, which exclude other similar conditions. The etiology and pathogenesis of KD remain unknown, with the disease affecting genetically susceptible children through an immune-mediated mechanism. The leading theory is that an unidentified trigger initiates a multi-organ inflammatory pathological cascade, sometimes resulting in incomplete or atypical forms in younger patients. For this reason, the American guidelines review KD diagnostic criteria, cardiac imaging techniques (echocardiography, coronary computed tomography, magnetic resonance imaging), specific therapies (intravenous immunoglobulin, aspirin, and additional treatments for resistant cases), management of myocardial infarctions, and the transition of care from pediatric to adult age. This review article also highlights future research areas, the role of inflammation, the development of differential diagnostic algorithms for multisystem inflammatory syndrome in children associated with SARS-CoV-2 infection, and the use of new oral anticoagulants. Lastly, the most recent data on the long-term course of the disease and the regression of coronary aneurysms are revisited.

Bacille Calmette-Guérin Scar Reactivation in Kawasaki Disease.

Kawasaki disease (KD) is a multisystemic vasculitis of unknown aetiology in children. KD with coronary artery lesion (CAL) is now the leading acquired heart disease in children. Peripheral blood mononuclear cells (PBMCs) play roles in KD. We identified hub genes based on RNA sequencing data and validated them in PBMCs and human umbilical vein endothelial cells (HUVECs) co-culture with PBMCs. Expression profiling by high throughput sequencing (RNA-seq data) PBMCs from 12 acute KD patients and 12 healthy controls was performed to screen differentially expressed mRNAs (DE-mRNAs). We selected 20 KD with CAL, 20 KD patients without CAL and 40 healthy controls for validation, and established HUVECs co-culture with PBMCs. Real time-PCR was finally conducted to confirm the reliability and validity of the expression level of DE-mRNAs from PBMC-HUVECs co-cultures. A total of 6039 DE-mRNAs were found (2267 upregulated, 3772 downregulated). Thirty hub genes were selected. KD PBMCs significantly impaired HUVECs viability and migration. IL1R2 was downregulated, FCGR1A, and CD177 mRNAs were upregulated in acute KD and KD with CAL. IL1R2 was elevated, FCGR1A and CD177 mRNAs were downregulated in convalescence and KD without CAL. And the real-time PCR and ELISA results showed IL1R2 was downregulated in acute KD PBMC-HUVECs co-cultures and elevated in convalescence. These findings may improve our understanding of PBMCs and PBMC-HUVECs co-cultures with PBMCs in KD.

Kawasaki disease is a systemic vasculitis of unknown aetiology that is usually seen in children younger than five years of age. In our study, the demographic, clinical, laboratory, and echocardiographic characteristics of children diagnosed with Kawasaki disease were evaluated, and patients were compared between complete and incomplete Kawasaki disease, as well as according to the presence or absence of coronary artery involvement. This retrospective study included 35 paediatric patients diagnosed with Kawasaki disease. Patients were classified as having complete Kawasaki disease or incomplete Kawasaki disease and were further stratified based on the presence or absence of coronary artery involvement. Laboratory parameters were compared between patients with and without coronary artery involvement before treatment and one week after treatment. The study included 35 patients, 71.4% of whom were male (n = 25). Complete Kawasaki disease was diagnosed in 68.6% of patients, and coronary artery involvement was detected in 37.1%. Patients with complete Kawasaki disease had more frequent extremity changes (p = 0.011), higher C-reactive protein (p = 0.014), and lower alanine aminotransferase levels (p = 0.014) than those with incomplete Kawasaki disease. Patients with coronary artery involvement were younger (p = 0.001), had longer hospitalisation (p = 0.020), prolonged fever before intravenous immunoglobulin treatment (p = 0.003), and delayed defervescence (p = 0.028) compared to patients without coronary artery involvement. Before treatment, erythrocyte sedimentation rate (p = 0.033), lymphocyte (p = 0.022), and platelet (p = 0.001) were higher in patients with coronary artery involvement, whereas no significant differences were observed after treatment. Patients with coronary artery involvement in Kawasaki disease were younger and exhibited more pronounced inflammatory findings compared with those without involvement; however, these inflammatory differences disappeared after treatment. This finding supports the importance of early and effective treatment during the acute phase.

Discovery and characterization of hinokiflavone as a potent natural CD137 inhibitor for Kawasaki disease.

Updated highlights of the new AHA scientific statement on the diagnosis and management of Kawasaki disease and differences among relevant guidelines or consensus statements across countries

A possible shared 4-6-week latency between MIS-C and Kawasaki disease: epidemiological insights from Japan.

Detection of coronary artery aneurysm in children with Kawasaki disease: a prospective study using contrast-enhanced coronary MRA with combined diastolic and systolic phases imaging at 3T.

Kawasaki disease (KD) is a leading cause of acquired heart disease in children, requiring timely diagnosis. Circulating microRNAs (miRNAs) are promising non-invasive biomarkers for KD, but their accurate quantification is challenged by low abundance, high sequence homology, and complex biological matrices. Herein, we report a self-priming cascade amplification strategy using a structurally stabilized ternary hybridization probe for sensitive and reliable detection of KD-related miRNAs. The rationally designed probe integrates three oligonucleotides into a robust complex, suppressing nonspecific background signals. Upon target recognition, an orchestrated cascade is activated, including target recycling, polymerase-assisted extension, and nicking endonuclease-mediated exponential amplification, ultimately generating a G-quadruplex-enhanced fluorescence readout. Under optimized conditions, this method achieves a detection limit of 0.82 fM with a dynamic range from 1 fM to 10 nM, and excellent discrimination against mismatched sequences. The assay shows outstanding robustness in human serum, with recovery rates of 96.7-103% and strong correlation with qRT-PCR. Key innovations include the stabilized ternary probe that minimizes background noise and the multi-layered amplification cascade that enhances sensitivity, overcoming the trade-off between stability and efficiency in self-priming systems. This isothermal and robust platform holds great promise for early diagnosis of Kawasaki disease and can be extended to other nucleic acid biomarkers.

Most medium to small-sized coronary artery aneurysms (CAAs) caused by Kawasaki disease (KD) can regress. To clarify the outcomes of patients with regressed-CAAs (r-CAAs). We reviewed characteristics and outcomes in 139 patients (male, 101; female, 38) with r-CAAs between 1978 and 2022 using medical records, including coronary angiograms and coronary computed tomography angiograms (CCTAs). The prevalence of localized stenosis (LS) and outcomes were calculated using the Kaplan-Meier method. Furthermore, the cut-off points of the maximum CAA diameter in the initial angiogram for coronary artery calcification (CAC) in late CCTAs were analyzed. The 25-year incidence of LS was 9.8% (95% CI, 3.6-23.8), and the 25-year cardiac event-free survival rate was 95.3% (95% CI 72.9-99.3). All LS cases were associated with CAC. Cut-off values of the initial maximum CAA diameter for CAC in branches and at bifurcations were 4.9mm (n = 129, AUC 0.859, p < 0.0001) and 5.7mm (n = 43, AUC 0.951, p = 0.0013), respectively. The corresponding Z scores were 6.75 (AUC 0.846, p < 0.0001) and 6.65 (AUC 0.921, p = 0.0014), respectively. The cut-off value of the interval time from the onset of KD to CAC detection was 10.0 years (AUC 0.673, p = 0.0053) in branches. LS with CAC in patients with r-CAAs can occur more than 10 years after the onset of KD. CAC after CAA regression is likely to appear at a maximum diameter of more than 5.0mm (z score 6.7) in young adults; however, it may appear with aging in smaller r-CAAs.

Mycoplasma pneumoniae is a common cause of respiratory infections, which in some cases leads to extrapulmonary complications, including mucocutaneous eruptions. The authors describe a clinical case of a 5-year-old Polish boy presenting with symptoms consistent with the diagnostic criteria of Mycoplasma pneumoniae-induced rash and mucositis (MIRM), a relatively new clinical entity distinguished from the spectrum of erythema multiforme (EM), Stevens-Johnson syndrome (SJS), and toxic epidermal necrolysis (TEN). The patient was initially admitted to the acute admissions unit of the Children's Health Centre in Poznan, Poland, due to prolonged fever, erosive-ulcerative lesions of the oral mucosa and lips, and slightly elevated, pink, rash-like skin eruptions. After 2months, he was followed up in the University outpatient department. The treatment included systemic and local steroids (hydrocortisone, prednisolone), antibiotics (gentamicin), mucolytics (ambroxol), analgesics (paracetamol), and local antifungal agents (nystatin). This report discusses the clinical presentation, diagnostic procedures, differential diagnosis, and treatment. We recommend that pneumonia accompanied by mucocutaneous eruptions, especially in young patients, should raise clinical suspicion of MIRM. Differential diagnosis should include EM, SJS, TEN, and Kawasaki disease.

Coronary artery lesions (CALs) represent the most serious complications of Kawasaki disease (KD), and the early identification of children at high risk for CALs is critical for guiding treatment strategies. This study aimed to develop a nomogram-based model to predict the risk of CALs in children with KD. This retrospective analysis enrolled 255 children diagnosed with KD between January 2024 and May 2025. Feature selection was performed using the least absolute shrinkage and selection operator regression. Variables with non-zero coefficients were subsequently incorporated into multivariable logistic regression to identify risk factors associated with CALs. A nomogram was constructed based on these predictors, and internal validation was performed using the bootstrap resampling method. The performance of the model was assessed using receiver operating characteristic (ROC) curves, calibration curves, the Hosmer-Lemeshow goodness-of-fit test, and decision curve analysis (DCA). The incidence of CALs in children with KD was 29.4% (75/255). Our results identified age, clinical type, platelet count (PLT), and thrombin time (TT) as independent risk factors for CALs in children with KD. The area under the ROC curve of the model was 0.807 (95% confidence interval [CI] = 0.750-0.860). The calibration curves and the Hosmer-Lemeshow goodness-of-fit test revealed good consistency between the predicted probabilities and observed outcomes, and DCA confirmed that the model had good clinical utility. We developed and internally validated a nomogram-based predictive model based on age, clinical type, PLT, and TT that may facilitate the early identification of children with KD at high risk of developing CALs.

Association between prenatal exposure to air pollution and risk of Kawasaki disease in young children of South Korea: Big children's environmental health study.

To investigate the effect of miR-155-5p regulation of the TLR4/MAPK/NF-κB pathway on inflammatory response, coronary artery lesion, and immune function in mice with Kawasaki disease (KD). Sixty male BALB/C mice were randomly assigned to six groups (n=10 each): healthy, KD, miR-155-5p agomir, agomir-negative control (agomir-NC), miR-155-5p antagomir, and antagomir-negative control (antagomir-NC). KD models were established by intraperitoneal injection of Lactobacillus casei cell wall extract in all groups except the healthy group. Levels of interleukin (IL)-6, IL-1β, and tumor necrosis factor (TNF)-α were measured by ELISA. Flow cytometry was used to determine the proportions of CD3+, CD4+, and CD8+ T lymphocyte subsets and the CD4+/CD8+ ratio. Coronary artery diameter was assessed by high-frequency ultrasound, and histopathological changes were observed by hematoxylin-eosin staining. Endothelial cell apoptosis in coronary tissue was detected with TUNEL staining. Expression levels of nuclear factor kappa-B (NF-κB) p65, phosphorylated NF-κB p65 (p-NF-κB p65), Toll-like receptor 4 (TLR4), and p38 mitogen-activated protein kinase (MAPK) proteins were analyzed by Western blot. Compared with the healthy group, the KD group showed coronary arterial wall thickening, endothelial shedding, extensive inflammatory cell infiltration, disordered smooth muscle layer arrangement, vascular dilation, and lumen stenosis. The miR-155-5p agomir group exhibited aggravated coronary inflammation, wall thickening, and lumen stenosis versus the KD group, whereas the miR-155-5p antagomir group showed attenuated inflammation and wall thickening, improved smooth muscle arrangement, and reduced stenosis. The KD group demonstrated increased IL-6, IL-1β, TNF-α, CD4+ T cell percentage, CD4+/CD8+ ratio, coronary artery diameter, endothelial apoptosis rate, and p-NF-κB p65, TLR4, and p38 MAPK protein expression compared to the healthy group (all P<0.05), with decreased CD3+ and CD8+ T cell percentages (P<0.05). No significant differences were observed among the KD, agomir-NC, and antagomir-NC groups. Compared with the KD group, the miR-155-5p agomir group showed further increased inflammatory cytokines (IL-6, IL-1β, and TNF-α), CD4+ T cell percentage, CD4+/CD8+ ratio, coronary diameter, endothelial apoptosis, and protein expression of p-NF-κB p65, TLR4, and p38 MAPK, while reduced CD3+ and CD8+ T cell percentages (all P<0.05). Conversely, the miR-155-5p antagomir group showed significant reductions in inflammatory cytokines, protein expression of p-NF-κB p65, TLR4, and p38 MAPK, CD4+ T cell percentage, CD4+/CD8+ ratio, coronary artery diameter, and endothelial apoptosis, as well as significant increases in CD3+ and CD8+ T cell percentages (all P<0.05). Overexpression of miR-155-5p exacerbates inflammatory response, coronary artery lesions, endothelial cell apoptosis, and immune dysfunction in KD, potentially through modulation of the TLR4/MAPK/NF-κB pathway. Inhibition of miR-155-5p may reverse these pathological changes.

BackgroundIntravenous immunoglobulin (IVIG) resistance is a major clinical challenge in children with Kawasaki disease (KD) and is associated with an increased risk of coronary artery lesions. Early identification of patients at high risk of IVIG resistance remains clinically important.MethodsMedical data were collected from KD patients at Anhui Provincial Hospital between January 2018 and December 2023. Multivariable logistic regression was performed to identify independent risk factors for IVIG resistance in KD. The study further performed subgroup analyses and restricted cubic spline (RCS) to visualize the dose–response association between hemoglobin–albumin–lymphocyte–platelet score (HALP) and IVIG resistance. The predictive performance of HALP was evaluated using receiver operating characteristic (ROC) curves and decision curve analysis (DCA), and internal validation was performed using bootstrap resampling.ResultsA total of 598 patients were included, of whom 58 (9.7%) were identified as IVIG-resistant. Patients with IVIG-resistant KD had significantly lower HALP scores, and low HALP was identified as an independent risk factor for IVIG resistance. The association was consistent across subgroups defined by age, sex, and incomplete KD (IKD). The area under the curve (AUC) for HALP in predicting IVIG resistance was 0.854, outperforming NLR (AUC = 0.751), PLR (AUC = 0.793), and SII (AUC = 0.759). In addition, DCA showed that HALP provided greater net benefit when the threshold probability ranged from 0.02 to 0.63. Moreover, subgroup ROC indicated that HALP had higher predictive value in patients aged ≤ 6 months (AUC = 0.934) and ≥ 48 months (AUC = 0.947).ConclusionsHALP is independently associated with IVIG resistance in children with KD and demonstrated good performance for early risk stratification, particularly in patients aged ≤ 6 months and ≥ 48 months. As a simple and readily available biomarker, HALP may serve as a useful complementary tool in routine pediatric clinical practice.Supplementary InformationThe online version contains supplementary material available at 10.1186/s13052-026-02288-5.

To identify key cytokines for the differentiation and treatment monitoring of haemophagocytic lymphohistiocytosis (HLH). We retrospectively analysed the clinical data and cytokine profiles from 66 patients with HLH, sepsis, Kawasaki disease (KD) and infectious mononucleosis (IM). Hierarchical clustering analysis was performed among those diseases. The diagnostic value of the markers was assessed using logistic regression and receiver operating characteristic (ROC) curves. Longitudinal changes in cytokines were detected in HLH patients. Cluster analysis revealed substantial overlap in the cytokine profiles between HLH and IM, characterized by high levels of C-X-C motif chemokine ligand 9 (CXCL9), C-X-C motif chemokine ligand 10 (CXCL10), interferon-gamma (IFN-γ), solublecluster of differentiation 25 (sCD25) and interleukin-18 (IL-18). The cytokine profiles differed from sepsis and KD patients. The combined detection of CXCL9 and haemoglobin (Hb) achieved an area under the curve (AUC) of 0.943 for distinguishing Epstein-Barr virus-related HLH (EBV-HLH) from IM. CXCL9 was significantly correlated with aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in HLH patients. Moreover, high levels of CXCL9 were associated with more severe clinical manifestations. During the monitoring of HLH cases, trends in CXCL9 and LDH levels correlated with disease progression.In conclusion, differences in cytokine profiles contribute to disease differentiation, and detection of CXCL9 holds promise for HLH diagnosis and longitudinal monitoring.

Heat-related increase in Kawasaki disease risk with delayed effects: Evidence from time-series and case-crossover analyses in Seoul, South Korea.

Club Rhumatismes et Inflammation guidelines for anti-interleukin-1 therapy: 2026 update.

Large language models can synthesize biomedical knowledge, parse vast amounts of data, and generate code, positioning them as promising tools for biomarker discovery from high-throughput omics data. Here, we benchmark six models from OpenAI, Anthropic, and Google on plasma cell-free RNA datasets spanning three clinical cohorts: Kawasaki disease versus multisystem inflammatory syndrome in children, active tuberculosis versus symptomatic respiratory controls, and myalgic encephalomyelitis/chronic fatigue syndrome versus sedentary controls. We evaluate literature-guided nomination of diagnostic gene panels for downstream machine learning and autonomous construction of end-to-end classifiers from raw count matrices to held-out test predictions. Despite prompt adherence issues, model-nominated panels recapitulate canonical immune pathways and outperform random panels across cohorts, even matching differential gene expression baselines in the tuberculosis cohort. End-to-end automation proves feasible but is model- and task-dependent. One model approaches conventional performance for Kawasaki disease versus multisystem inflammatory syndrome in children, whereas performance decreases for tuberculosis and myalgic encephalomyelitis/chronic fatigue syndrome cohorts. These findings delineate current capabilities and limitations of large language models in diagnostics and open a path for their future use in biomarker discovery.

Multisystem inflammatory syndrome in children (MIS-C) is a severe hyperinflammatory condition associated with SARS-CoV-2 infection and is frequently complicated by cardiovascular dysfunction, particularly shock. Early recognition of shock in MIS-C is critical to reduce morbidity and mortality. This systematic review and meta-analysis aimed to evaluate the prevalence, comparative risk, and predictors of shock among children with MIS-C, enhancing clinical management and informing future research. A systematic search of PubMed, Embase and Web of Science was conducted from database inception to 15 July 2025. Observational studies reporting prevalence, comparative risk or predictors of shock in children with MIS-C were included. Random-effects meta-analysis with Freeman-Tukey double arcsine transformation was used to estimate pooled prevalence with 95% confidence intervals (CI). Relative risks (RR) were pooled for comparative analyses. Subgroup analyses, sensitivity analyses and meta-regression were performed to explore heterogeneity. Publication bias was assessed using funnel plots and Egger's regression test. Seventy studies involving 13 263 children with MIS-C were included. The pooled prevalence of shock was 56% (95% CI: 49%-63%), although substantial heterogeneity was observed (I2 = 98.4%). Sensitivity analyses excluding studies with sample sizes < 50 and < 100 participants yielded pooled prevalence estimates of 50% (95% CI: 40%-59%) and 46% (95% CI: 33%-59%), respectively. Subgroup analyses demonstrated variation according to publication year and diagnostic criteria. Children with MIS-C had a significantly increased risk of shock compared with Kawasaki disease cohorts (RR = 8.52, 95% CI: 1.24-58.41; p < 0.05) and acute/severe COVID-19 cohorts without MIS-C (RR = 4.42, 95% CI: 2.44-8.02; p < 0.001). Echocardiographic abnormalities, myocardial dysfunction, elevated inflammatory markers and acute kidney injury were consistently associated with shock. The certainty of evidence ranged from very low to low because of substantial heterogeneity, imprecision and methodological variability across studies. Despite these limitations, shock remains a frequent and serious complication of MIS-C, highlighting the importance of early cardiovascular assessment and timely recognition of high-risk children.