Circulating Immune Cell Profile and Changes in Intravenous Immunoglobulin Responsiveness Over the Disease Course in Children With Kawasaki Disease

Platelet-Monocyte Aggregate Instigates Inflammation and Vasculopathy in Kawasaki Disease

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.

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.

Pharmacogenomics of coronary artery response to intravenous gamma globulin in kawasaki disease

Kawasaki disease (KD) is a multisystem inflammatory illness of infants and young children that can result in acute vasculitis. The mechanism of coronary artery aneurysms (CAA) in KD despite intravenous gamma globulin (IVIG) treatment is not known. We performed a Whole Genome Sequencing (WGS) association analysis in a racially diverse cohort of KD patients treated with IVIG, both using AHA guidelines. We defined coronary aneurysm (CAA) (N = 234) as coronary z ≥ 2.5 and large coronary aneurysm (CAA/L) (N = 92) as z ≥ 5.0. We conducted logistic regression models to examine the association of genetic variants with CAA/L during acute KD and with persistence >6 weeks using an additive model between cases and 238 controls with no CAA. We adjusted for age, gender and three principal components of genetic ancestry. The top significant variants associated with CAA/L were in the intergenic regions (rs62154092 p < 6.32E-08 most significant). Variants in SMAT4, LOC100127, PTPRD, TCAF2 and KLRC2 were the most significant non-intergenic SNPs. Functional mapping and annotation (FUMA) analysis identified 12 genomic risk loci with eQTL or chromatin interactions mapped to 48 genes. Of these NDUFA5 has been implicated in KD CAA and MICU and ZMAT4 has potential functional implications. Genetic risk score using these 12 genomic risk loci yielded an area under the receiver operating characteristic curve (AUC) of 0.86. This pharmacogenomics study provides insights into the pathogenesis of CAA/L in IVIG-treated KD and shows that genomics can help define the cause of CAA/L to guide management and improve risk stratification of KD patients.

Pharmacogenomics of Coronary Artery Response to Intravenous Gamma Globulin in Kawasaki Disease

Background

Kawasaki disease (KD) is a multisystem inflammatory illness of infants and young children that can result in acute vasculitis. The pathological walls of afflicted coronary arteries show propensity for forming thrombosis and aneurysms. The mechanism of coronary artery aneurysms (CAA) despite intravenous gamma globulin (IVIG) treatment is not known.

Methods

We performed a Whole Genome Sequencing (WGS) association analysis in a racially diverse cohort of KD patients treated with IVIG, both using AHA guidelines. We defined coronary aneurysm (CAA) (N = 234) as coronary z>2.5 and large coronary aneurysm (CAA/L) (N = 92) as z>5.0. We conducted logistic regression models to examine the association of genetic variants with CAA/L during acute KD and with persistence >6 weeks using an additive model between cases and 238 controls with no CAA. We adjusted for age, gender and three principal components of genetic ancestry. We performed functional mapping and annotation (FUMA) analysis and further assessed the predictive risk score of genomic risk loci using the area under the receiver operating characteristic curve (AUC).

Results

The top significant variants associated with CAA/L were in the intergenic regions (rs62154092 p<6.32E-08 most significant). Variants in SMAT4, LOC100127 , PTPRD, TCAF2 and KLRC2 were the most significant non-intergenic SNPs. FUMA identified 12 genomic risk loci with eQTL or chromatin interactions mapped to 48 genes. Of these NDUFA5 has been implicated in KD CAA and MICU and ZMAT4 has potential functional implications. Genetic risk score using these 12 genomic risk loci yielded an AUC of 0.86.

Conclusions

This pharmacogenomics study provides insights into the pathogenesis of CAA/L in IVIG-treated KD patients. We have identified multiple novel SNPs associated with CAA/L and related genes with potential functional implications. The study shows that genomics can help define the cause of CAA/L to guide management and improve risk stratification of KD patients.

[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.

Integration of scRNA-Seq and bulk RNA-Seq uncover perturbed immune cell types and pathways of Kawasaki disease

Introduction

Kawasaki disease (KD) is an acute febrile illness primarily affecting children and characterized by systemic inflammation and vasculitis that can lead to coronary artery complications. The aim of this study was to gain a comprehensive understanding of immune dysregulation in KD.

Methods

To this end, we employed integration of single-cell RNA sequencing (scRNA-Seq) and bulk RNA sequencing (bulk RNA-Seq) data. Furthermore, we conducted flow cytometry analysis for a cohort of 82 KD patients.

Results

Our analysis revealed significant heterogeneity within immune cell populations in KD patients, with distinct clusters of T cells, B cells, and natural killer (NK) cells. Importantly, CD4+ naïve T cells in KD patients were found to predominantly differentiate into Treg cells and Th2 cells, potentially playing a role in the excessive inflammation and vascular damage characteristic of the disease. Dysregulated signaling pathways were also identified, including the mTOR signaling pathway, cardiomyopathy pathway, COVID-19 signaling pathway, and pathways involved in bacterial or viral infection.

Discussion

These findings provide insights into the immunopathogenesis of KD, emphasizing the importance of immune cell dysregulation and dysregulated signaling pathways. Integration of scRNA-Seq and bulk RNA-Seq data offers a comprehensive view of the molecular and cellular alterations in KD and highlights potential therapeutic targets for further investigation. Validation and functional studies are warranted to elucidate the roles of the identified immune cell types and pathways in KD pathogenesis and to develop targeted interventions to improve patient outcomes.

The CD56-CD16+ NK cell subset in chronic infections

Long-term human diseases can shape the immune system, and natural killer (NK) cells have been documented to differentiate into distinct subsets specifically associated with chronic virus infections. One of these subsets found in large frequencies in HIV-1 are the CD56-CD16+ NK cells, and this population's association with chronic virus infections is the subject of this review. Human NK cells are classically defined by CD56 expression, yet increasing evidence supports the NK cell status of the CD56-CD16+ subset which we discuss herein. We then discuss the evidence linking CD56-CD16+ NK cells to chronic virus infections, and the potential immunological pathways that are altered by long-term infection that could be inducing the population's differentiation. An important aspect of NK cell regulation is their interaction with human leukocyte antigen (HLA) class-I molecules, and we highlight work that indicates both virus and genetic-mediated variations in HLA expression that have been linked to CD56-CD16+ NK cell frequencies. Finally, we offer a perspective on CD56-CD16+ NK cell function, taking into account recent work that implies the subset is comparable to CD56+CD16+ NK cell functionality in antibody-dependent cell cytotoxicity response, and the definition of CD56-CD16+ NK cell subpopulations with varying degranulation capacity against target cells.

MicroRNAs in Kawasaki disease: An update on diagnosis, therapy and monitoring

Kawasaki disease (KD) is an acute autoimmune vascular disease featured with a long stage of febrile. It predominantly afflicts children under 5 years old and causes an increased risk of cardiovascular combinations. The onset and progression of KD are impacted by many aspects, including genetic susceptibility, infection, and immunity. In recent years, many studies revealed that miRNAs, a novel class of small non-coding RNAs, may play an indispensable role in the development of KD via differential expression and participation in the central pathogenesis of KD comprise of the modulation of immunity, inflammatory response and vascular dysregulation. Although specific diagnose criteria remains unclear up to date, accumulating clinical evidence indicated that miRNAs, as small molecules, could serve as potential diagnostic biomarkers and exhibit extraordinary specificity and sensitivity. Besides, miRNAs have gained attention in affecting therapies for Kawasaki disease and providing new insights into personalized treatment. Through consanguineous coordination with classical therapies, miRNAs could overcome the inevitable drug-resistance and poor prognosis problem in a novel point of view. In this review, we systematically reviewed the existing literature and summarized those findings to analyze the latest mechanism to explore the role of miRNAs in the treatment of KD from basic and clinical aspects retrospectively. Our discussion helps to better understand the pathogenesis of KD and may offer profound inspiration on KD diagnosis, treatment, and prognosis.