Atlas of circulating immune cells in Kawasaki disease

Kawasaki Disease: An update on Genetics and Pathophysiology

Kawasaki disease (KD), a systemic vasculitic condition predominantly affecting children, remains a significant challenge in pediatric health care. First identified in 1967, KD is now recognized as the primary cause of pediatric ischemic heart disease in developed countries. This review provides a comprehensive update of KD, focusing on biomarkers, pathophysiology, and genetic associations. KD's clinical manifestation, including symptoms such as persistent fever and mucocutaneous changes, often overlaps with other pediatric conditions, complicating its diagnosis. This ambiguity, especially in cases of incomplete KD, highlights the critical need for specific biomarkers and more precise diagnostic methods. Recent studies have made promising advancements in identifying serum biomarkers and microRNAs, contributing to the development of rapid diagnostic tools. However, these are yet to be fully integrated into clinical practice. The article focuses on the pathophysiological aspects of KD, highlighting the potential for targeted therapies and personalized medicine approaches based on genetic predispositions. Collaborative efforts in global research and raising public awareness about KD are emphasized as key strategies for improving its management. This review presents the current understanding of KD while pointing out the gaps and future directions in research and clinical care. The ultimate goal is to enhance diagnostic accuracy, optimize treatment strategies, and improve patient outcomes, thereby addressing the complexities of this enigmatic and potentially life-threatening condition in pediatric medicine.

Multi-modal immune dynamics of pre-COVID-19 Kawasaki disease following intravenous immunoglobulin

Despite progress, the molecular mechanisms underlying Kawasaki Disease (KD) and intravenous immunoglobulin's (IVIG) ability to mitigate the inflammatory process remain poorly understood. To characterize this condition, plasma proteomic profiles, flow cytometry, and gene expression of T cell subsets were investigated in longitudinal samples from KD patients and compared with two control groups. Systems-level analysis of samples in the acute phase revealed distinctive inflammatory features of KD, involving mainly Th-1 and Th-17 mediators, and unveiled a potential disease severity signature. APBB1IP demonstrated an association with coronary artery involvement (CAI) and was significantly higher in CAI+ compared to CAI- patients. Integrative analysis revealed a transient reduction in CD4+ EM T cells and comprehensive immune activation and exhaustion. Following treatment, Tregs at both frequency and gene expression levels revealed immune dynamics of recovery. Overall, our data provide insights into KD, which may offer valuable information on prognostic indicators and possible targets for novel treatments.

Single-cell transcriptome landscape of circulating CD4+ T cell populations in autoimmune diseases

CD4+ T cells are key mediators of various autoimmune diseases; however, their role in disease progression remains unclear due to cellular heterogeneity. Here, we evaluated CD4+ T cell subpopulations using decomposition-based transcriptome characterization and canonical clustering strategies. This approach identified 12 independent gene programs governing whole CD4+ T cell heterogeneity, which can explain the ambiguity of canonical clustering. In addition, we performed a meta-analysis using public single-cell datasets of over 1.8 million peripheral CD4+ T cells from 953 individuals by projecting cells onto the reference and cataloging cell frequency and qualitative alterations of the populations in 20 diseases. The analyses revealed that the 12 transcriptional programs were useful in characterizing each autoimmune disease and predicting its clinical status. Moreover, genetic variants associated with autoimmune diseases showed disease-specific enrichment within the 12 gene programs. The results collectively provide a landscape of single-cell transcriptomes of CD4+ T cell subpopulations involved in autoimmune disease.

[Predictive value of peripheral blood lymphocyte subsets for children with intravenous immunoglobulin-resistant Kawasaki disease]

OBJECTIVES

Based on peripheral blood lymphocyte subsets and common laboratory test indexes, this study aimed to construct a predictive scoring system for intravenous immunoglobulin (IVIG)-resistant Kawasaki disease (KD).

METHODS

Children hospitalized in Tianjin Children's Hospital from January 2021 to March 2023 were included in the study (185 cases of IVIG-sensitive KD and 41 cases of IVIG -resistant KD). Forty-six healthy children matched for age and gender were selected as controls. The relative percentage and absolute counts of peripheral lymphocyte subsets were measured by flow cytometry. Multivariate logistic regression was used to identify the predictive factors for IVIG-resistant KD and to construct a predictive scoring system for predicting IVIG-resistant KD.

RESULTS

The multivariate logistic regression analysis showed that CD4+ T cell absolute count, natural killer cell absolute count, serum sodium level, globulin level, and total bilirubin level were identified as predictive factors for IVIG-resistant KD (P<0.05). The predictive scoring system based on these factors achieved a sensitivity of 70.7% and a specificity of 83.8% in predicting IVIG-resistant KD.

CONCLUSIONS

Peripheral blood lymphocyte subsets can serve as predictive indicators for IVIG-resistant KD in children. The introduction of this indicator and the establishment of a scoring system based on it can provide a higher accuracy in predicting IVIG-resistant KD in children.

Identification of hub biomarkers and immune-related pathways participating in the progression of Kawasaki disease by integrated bioinformatics analysis

BACKGROUND

Kawasaki disease (KD) is a systemic vasculitis that commonly affects children and its etiology remains unknown. Growing evidence suggests that immune-mediated inflammation and immune cells in the peripheral blood play crucial roles in the pathophysiology of KD. The objective of this research was to find important biomarkers and immune-related mechanisms implicated in KD, along with their correlation with immune cells in the peripheral blood.

MATERIAL/METHODS

Gene microarray data from the Gene Expression Omnibus (GEO) was utilized in this study. Three datasets, namely GSE63881 (341 samples), GSE73463 (233 samples), and GSE73461 (279 samples), were obtained. To find intersecting genes, we employed differentially expressed genes (DEGs) analysis and weighted gene co-expression network analysis (WGCNA). Subsequently, functional annotation, construction of protein-protein interaction (PPI) networks, and Least Absolute Shrinkage and Selection Operator (LASSO) regression were performed to identify hub genes. The accuracy of these hub genes in identifying KD was evaluated using the receiver operating characteristic curve (ROC). Furthermore, Gene Set Variation Analysis (GSVA) was employed to explore the composition of circulating immune cells within the assessed datasets and their relationship with the hub gene markers.

RESULTS

WGCNA yielded eight co-expression modules, with one hub module (MEblue module) exhibiting the strongest association with acute KD. 425 distinct genes were identified. Integrating WGCNA and DEGs yielded a total of 277 intersecting genes. By conducting LASSO analysis, five hub genes (S100A12, MMP9, TLR2, NLRC4 and ARG1) were identified as potential biomarkers for KD. The diagnostic value of these five hub genes was demonstrated through ROC curve analysis, indicating their high accuracy in diagnosing KD. Analysis of the circulating immune cell composition within the assessed datasets revealed a significant association between KD and various immune cell types, including activated dendritic cells, neutrophils, immature dendritic cells, macrophages, and activated CD8 T cells. Importantly, all five hub genes exhibited strong correlations with immune cells.

CONCLUSION

Activated dendritic cells, neutrophils, and macrophages were closely associated with the pathogenesis of KD. Furthermore, the hub genes (S100A12, MMP9, TLR2, NLRC4, and ARG1) are likely to participate in the pathogenic mechanisms of KD through immune-related signaling pathways.

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

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

Predicting immunoglobulin resistance in Kawasaki disease: an assessment of neutrophil to lymphocyte platelet ratio

BACKGROUND

Kawasaki disease (KD) is an acute febrile illness of unknown etiology and predictors for intravenous immunoglobulin (IVIG) resistance have been widely explored in recent decades. Neutrophil to lymphocyte platelet ratio (NLPR) was reported to be associated with the outcomes in many diseases. However, its relationship with IVIG resistance has not be explored.

METHODS

The medical data of patients diagnosed with KD in Children's Hospital of Soochow University between January 2019 and December 2020 were retrospectively reviewed and analyzed. Patients were trisected into three groups based on NLPR. Logistics regression was used to analyze the association between NLPR and IVIG resistance. Restricted cubic spine was used to exhibit the relationship. Sensitivity analysis and subgroup analysis were also carried out.

RESULTS

A total of 803 patients were included in the present study (61.8% males; median age: 24 months). IVIG resistance occurred in 74 (9.2%) patients. Multivariable-adjusted analyses revealed higher NLPR (odds ratio [95% confidence interval]: 1.12 [1.00-1.24]) was an independent predictor of IVIG resistance, which was strengthened by sensitivity analyses. The association of NLPR and IVIG resistance was not modified by age, sex, CALs, or days of IVIG initiation ≤ 4.

CONCLUSION

NLPR may be a valuable prognostic marker in KD patients with IVIG resistance.

Breastfeeding has no protective effects on the development of coronary artery lesions in Kawasaki disease: a retrospective cohort study

Background

Kawasaki disease (KD) is a self-limiting vasculitis with an unknown etiology. It has been reported that breastfeeding has a potential protective effect on KD development. However, whether breastfeeding has an effect on the development of coronary artery lesions (CALs) remains unclear.

Methods

We retrospectively reviewed the medical records of patients with the main diagnosis of KD hospitalized in our hospital from May 2017 to November 2018. Standardized telephone interviews were carried out to obtain feeding practices before KD was onset.

Results

Two hundred and ninety-three (51.6%) were exclusively breastfed, 223 (39.3%) were partially breastfed and 52 (9.2%) were formula fed. There were no significant differences in the characteristics regarding age, gender, incomplete KD, intravenous immunoglobulin (IVIG) resistance, and the laboratory variables among the three groups. With formula feeding as a reference, patients exclusively breastfed and partially breastfed seemed to have a higher incidence of CALs, even after adjusting confounders, but were not statistically significant. After grouping patients who were older than six months into formula feeding, partial breastfeeding for < 2 months, partial breastfeeding for ≥ 2 and < 4 months, partial breastfeeding for ≥ 4 and < 6 months and exclusively breastfeeding based on the length of breastfeeding, the results remained the same (P > 0.05).

Conclusions

Breastfeeding has no protective effect on the development of CALs in KD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03422-y.

Non-coding RNAs in Kawasaki disease: Molecular mechanisms and clinical implications

Kawasaki disease (KD) is an acute self-limiting vasculitis with coronary complications, usually occurring in children. The incidence of KD in children is increasing year by year, mainly in East Asian countries, but relatively stably in Europe and America. Although studies on KD have been reported, the pathogenesis of KD is unknown. With the development of high-throughput sequencing technology, growing number of regulatory noncoding RNAs (ncRNAs) including microRNA (miRNA), long noncoding RNA (lncRNA), and circular RNA (circRNA) have been identified to involved in KD. However, the role of ncRNAs in KD has not been comprehensively elucidated. Therefore, it is significative to study the regulatory role of ncRNA in KD, which might help to uncover new and effective therapeutic strategies for KD. In this review, we summarize recent studies on ncRNA in KD from the perspectives of immune disorders, inflammatory disorders, and endothelial dysfunction, and highlight the potential of ncRNAs as therapeutic targets for KD.