Identification of an association between genomic hypomethylation of FCGR2A and susceptibility to Kawasaki disease and intravenous immunoglobulin resistance by DNA methylation array

Fc gamma receptors: Their evolution, genomic architecture, genetic variation, and impact on human disease

Fc gamma receptors (FcγRs) are a family of receptors that bind IgG antibodies and interface at the junction of humoral and innate immunity. Precise regulation of receptor expression provides the necessary balance to achieve healthy immune homeostasis by establishing an appropriate immune threshold to limit autoimmunity but respond effectively to infection. The underlying genetics of the FCGR gene family are central to achieving this immune threshold by regulating affinity for IgG, signaling efficacy, and receptor expression. The FCGR gene locus was duplicated during evolution, retaining very high homology and resulting in a genomic region that is technically difficult to study. Here, we review the recent evolution of the gene family in mammals, its complexity and variation through copy number variation and single-nucleotide polymorphism, and impact of these on disease incidence, resolution, and therapeutic antibody efficacy. We also discuss the progress and limitations of current approaches to study the region and emphasize how new genomics technologies will likely resolve much of the current confusion in the field. This will lead to definitive conclusions on the impact of genetic variation within the FCGR gene locus on immune function and disease.

The Future of Kawasaki Disease Diagnosis: Liquid Biopsy May Hold the Key

Kawasaki disease (KD) is a febrile illness characterised by systemic inflammation of small- and medium-sized blood vessels, which commonly occurs in young children. Although self-limiting, there is a risk of developing coronary artery lesions as the disease progresses, with delay in diagnosis and treatment. Unfortunately, the diagnosis of KD continues to remain a clinical dilemma. Thus, this article not only summarises the key research gaps associated with KD, but also evaluates the possibility of using circulating endothelial injury biomarkers, such as circulating endothelial cells, endothelial microparticles and vascular endothelial cell-free DNA, as diagnostic and prognostic tools for KD: a "liquid biopsy" approach. The challenges of translating liquid biopsies to use in KD and the opportunities for improvement in its diagnosis and management that such translation may provide are discussed. The use of endothelial damage markers, which are easily obtained via blood collection, as diagnostic tools is promising, and we hope this will be translated to clinical applications in the near future.

Knowledge framework of intravenous immunoglobulin resistance in the field of Kawasaki disease: A bibliometric analysis (1997-2023)

BACKGROUND

Kawasaki disease (KD) is an autoimmune disease with cardiovascular disease as its main complication, mainly affecting children under 5 years old. KD treatment has made tremendous progress in recent years, but intravenous immunoglobulin (IVIG) resistance remains a major dilemma. Bibliometric analysis had not been used previously to summarize and analyze publications related to IVIG resistance in KD. This study aimed to provide an overview of the knowledge framework and research hotspots in this field through bibliometrics, and provide references for future basic and clinical research.

METHODS

Through bibliometric analysis of relevant literature published on the Web of Science Core Collection (WoSCC) database between 1997 and 2023, we investigated the cooccurrence and collaboration relationships among countries, institutions, journals, and authors and summarized key research topics and hotspots.

RESULTS

Following screening, a total of 364 publications were downloaded, comprising 328 articles and 36 reviews. The number of articles on IVIG resistance increased year on year and the top three most productive countries were China, Japan, and the United States. Frontiers in Pediatrics had the most published articles, and the Journal of Pediatrics had the most citations. IVIG resistance had been studied by 1889 authors, of whom Kuo Ho Chang had published the most papers.

CONCLUSION

Research in the field was focused on risk factors, therapy (atorvastatin, tumor necrosis factor-alpha inhibitors), pathogenesis (gene expression), and similar diseases (multisystem inflammatory syndrome in children, MIS-C). "Treatment," "risk factor," and "prediction" were important keywords, providing a valuable reference for scholars studying this field. We suggest that, in the future, more active international collaborations are carried out to study the pathogenesis of IVIG insensitivity, using high-throughput sequencing technology. We also recommend that machine learning techniques are applied to explore the predictive variables of IVIG resistance.

The causal effect of Helicobacter pylori infection on coronary heart disease is mediated by the body mass index: a Mendelian randomization study

The association between Helicobacter pylori (H. pylori) infection and coronary heart disease (CHD) remains controversial, with an unclear causal link. This study employed bidirectional Mendelian randomization (MR) method, using H. pylori infection as the exposure, to investigate its causal relationship with CHD diagnosis, prognosis, and potential pathogenesis. H. pylori infection exhibited a causal association with body mass index (BMI) (β = 0.022; 95% CI 0.008-0.036; p = 0.001). Conversely, there was no discernible connection between H. pylori infection and the diagnosis of CHD (OR = 0.991; 95% CI 0.904-1.078; p = 0.842; IEU database; OR = 1.049; 95% CI 0.980-1.118; p = 0.178; FinnGen database) or CHD prognosis (OR = 0.999; 95% CI 0.997-1.001; p = 0.391; IEU database; OR = 1.022; 95% CI 0.922-1.123; p = 0.663; FinnGen database). Reverse MR analysis showed no causal effect of CHD on H. pylori infection. Our findings further support that H. pylori infection exerts a causal effect on CHD incidence, mediated by BMI. Consequently, eradicating or preventing H. pylori infection may provide an indirect clinical benefit for patients with CHD.

The state of play in tools for predicting immunoglobulin resistance in Kawasaki disease

INTRODUCTION

Intravenous immunoglobulin (IVIG) resistance is an independent risk factor for the development of coronary artery lesions (CAL) in patients with Kawasaki disease (KD). Accurate identification of IVIG-resistant patients is one of the biggest clinical challenges in the treatment of KD.

AREAS COVERED

In this review article, we will go over current IVIG resistance scoring systems and other biological markers of IVIG resistance, with a particular focus on advances in machine-based learning techniques and high-throughput omics data.

EXPERT OPINION

Traditional scoring models, which were developed using logistic regression, including the Kobayashi score and Egami score, are inadequate at identifying IVIG resistance in non-Japanese populations. Newer machine-learning methods and high-throughput technologies including transcriptomic and epigenetic arrays have identified several potential targets for IVIG resistance including gene expression of the Fc receptor, and components of the interleukin (IL)-1β and pyroptosis pathways. As we enter an age where access to big data has become more commonplace, interpretation of large data sets that are able take into account complexities in patient populations will hopefully usher in a new era of precision medicine, which will enable us to identify and treat KD patients with IVIG resistance with increased accuracy.

Association of Genetic Polymorphisms in Kawasaki Disease with the Response to Intravenous Immunoglobulin Therapy

Kawasaki disease (KD) is an acute febrile and systemic vasculitis disease mainly affecting children < 5 years old. Although the first case of KD was reported in 1967 and despite extensive research on KD since then, the cause of the disease remains largely unknown. The most common complications of KD are coronary artery lesions (CAL), which significantly increase the risk of coronary heart disease. The standard treatment for KD is high-dose intravenous immunoglobulin (IVIG) plus aspirin within 10 days from symptoms' appearance, which has been shown to decrease the incidence of CAL to 5-7%. Despite the benefits of IVIG, about 25% of the patients treated with IVIG develop resistance or are unresponsive to the therapy, which represents an important risk factor for CAL development. The cause of IVIG unresponsiveness has not been fully elucidated. However, the role of gene polymorphisms in IVIG response has been suggested. Herein, we comprehensively review genetic polymorphisms in KD that have been associated with IVIG resistance/unresponsiveness and further discuss available models to predict IVIG unresponsiveness.Kindly check and confirm inserted city in affiliation [1] is correctly identified.confirm.

The rs7404339 AA Genotype in CDH5 Contributes to Increased Risks of Kawasaki Disease and Coronary Artery Lesions in a Southern Chinese Child Population

Background

Kawasaki disease (KD) is an acute, self-limited febrile illness of unknown cause. And it predominantly affects children <5 years and the main complication is coronary artery lesion (CAL). Studies demonstrated that vascular endothelial cells (VECs) played a very important role in the CAL of KD. VE-cad encoded by CDH5 may exert a relevant role in endothelial cell biology through controlling the cohesion of the intercellular junctions. The pathogenesis of KD remains unclear and genetic factors may increase susceptibility of KD. However, the relationship between CDH5 polymorphisms and KD susceptibility has not been reported before. The present study is aimed at investigating whether the rs7404339 polymorphism in CDH5 is associated with KD susceptibility and CAL in a southern Chinese child population.

Methods and Results

We recruited 1,335 patients with KD and 1,669 healthy children. Each participant had supplied 2 mL of fresh blood in the clinical biologic bank at our hospital for other studies. Multiplex PCR is used to assess the genotypes of rs7404339 polymorphism in CDH5. According to the results, we found significant correlated relationship between rs7404339 polymorphism in CDH5 and KD susceptibility [AA vs. GG: adjusted odds ratio (OR) = 1.43, 95% confidence interval (CI) = 1.00-2.05; p = 0.0493; recessive model: adjusted OR = 1.44, 95% CI = 1.01-2.06, P = 0.0431]. In further stratified analysis, we found that children younger than 60 months (adjusted OR = 1.46, 95% CI = 1.01-2.10; p = 0.0424) and male (adjusted OR = 1.70, 95% CI = 1.09-2.65; p = 0.0203) with the rs7404339 AA genotype in CDH5 had a higher risk of KD than carriers of the GA/GG genotype. Furthermore, stratification analysis revealed that patients with the rs7404339 AA genotype exhibited the significantly higher onset risk for CAL than carriers of the GA/GG genotype (adjusted age and gender odds ratio = 1.56, 95% CI = 1.01-2.41; P = 0.0433).

Conclusion

Our results showed that rs7404339 AA genotype in CDH5 is significant associated with KD susceptibility. And children younger than 60 months and male with the rs7404339 AA genotype had a higher risk of KD than carriers with the GA/GG genotype. Furthermore, patients with the rs7404339 AA genotype exhibited a significantly higher risk of CAL complication than carriers of the GA/GG genotype.

KDmarkers: A biomarker database for investigating epigenetic methylation and gene expression levels in Kawasaki disease

Kawasaki disease (KD) is a form of acute systemic vasculitis that primarily affects children and has become the most common cause of acquired heart disease. While the etiopathogenesis of KD remains unknown, the diagnostic criteria of KD have been well established. Nevertheless, the diagnosis of KD is currently based on subjective clinical symptoms, and no molecular biomarker is yet available. We have previously performed and combined methylation array (Illumina HumanMethylation450 BeadChip) and transcriptome array (Affymetrix GeneChip Human Transcriptome Array 2.0) to identify genes that are differentially methylated/expressed in KD patients compared with control subjects. We have found that decreased methylation levels combined with elevated gene expression can indicate genes (e.g., toll-like receptors and CD177) involved in the disease mechanisms of KD. In this study, we constructed a database called KDmarkers to allow researchers to access these valuable potential KD biomarkers identified via methylation array and transcriptome array. KDmarkers provides three search modes. First, users can search genes differentially methylated and/or differentially expressed in KD patients compared with control subjects. Second, users can check the KD patient groups in which a given gene is differentially methylated and/or differentially expressed. Third, users can explore the DNA methylation levels and gene expression levels in all samples (KD patients and controls) for a particular gene of interest. We further demonstrated that the results in KDmarkers are strongly associated with KD immune responses. All analysis results can be downloaded for downstream experimental designs. KDmarkers is available online at https://cosbi.ee.ncku.edu.tw/KDmarkers/.

The Relationship Between Lipoprotein-Associated Phospholipase-A2 and Coronary Artery Aneurysm in Children With Kawasaki Disease

BACKGROUND

Coronary artery lesions including aneurysm, as the most severe complications of Kawasaki disease (KD), remain of great concern. Lipoprotein-associated phospholipase A2 (Lp-PLA2) is implicated in the regulation of inflammatory response and lipid metabolism. Since excessive inflammatory response and aberrant lipid metabolism have involved in the development of KD, we in this study sought to investigate the relationship between coronary artery aneurysm (CAA) and Lp-PLA2 and other blood parameters in children with KD.

METHODS

The participants included 71 KD patients, 63 healthy controls (HCs) and 51 febrile controls (FCs). KD patients were divided into KD-CAA (KD with CAA) group and KD-NCAA (KD without CAA) group. Serum Lp-PLA2 levels were measured using enzyme-linked immunosorbent assays. Other routine clinical parameters were also detected.

RESULTS

Serum Lp-PLA2 levels in KD group [4.83 μg/mL (3.95-6.77)] were significantly higher than those in HC [1.29 μg/mL (0.95-2.05)] and FC [1.74 μg/mL (1.18-2.74)] groups. KD-CAA group [5.56 μg/mL (4.55-22.01)] presented substantially higher serum Lp-PLA2 levels as compared with KD-NCAA group [4.64 μg/mL (2.60-5.55)]. In KD group, serum Lp-PLA2 level was positively related with erythrocyte sedimentation rate, the levels of leukocytes, platelets, albumin, creatine kinase-MB, and D-dimer, and the Z-scores of left main CA, right CA, left anterior descending CA, and left circumflex CA; and negatively related with mean corpuscular hemoglobin concentration and mean platelet volume. Moreover, receiver operating characteristic curves showed that Lp-PLA2 exhibited superior and moderate diagnostic performance for distinguishing KD patients from HC and FC ones, respectively, and possessed the potential ability to predict the occurrence of CAAs in KD.

CONCLUSION

Lp-PLA2 may be related to KD and the formation of CAAs, and thus may serve as a potential diagnostic biomarker for KD.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

Protective Effect of TNFRSF11A rs7239667 G > C Gene Polymorphism on Coronary Outcome of Kawasaki Disease in Southern Chinese Population

Background

The main symptoms of Kawasaki disease (KD) are inflammatory vasculitis characterized by fever lasting 1–2 weeks, failure to respond to antibiotic treatment, conjunctivitis, redness of the lips and mouth, strawberry tongue, and painless enlargement of the neck lymph nodes. Studies have been shown that tumor necrosis factor (TNF) and TNF receptor family members are abnormally expressed in the acute phase of Kawasaki disease, also revealing that these two play a significant role in the pathogenesis of KD. The purpose of our study is to determine the relationship between TNFRSF11A rs7239667 and the pathogenesis of KD and Coronary artery lesions in KD.

Methods and Results

In this study, TNFRSF11A (rs7239667) genotyping was performed in 1396 patients with KD and 1673 healthy controls. Our results showed that G > C polymorphism of TNFRSF11A (rs7239667) was not associated with KD susceptibility. In addition, the patients with KD were divided into CAA and NCAA groups according to whether they had coronary artery aneurysm (CAA) or not, and the TNFRSF11A rs7239667 genotyping was performed in the two groups. After gender and age calibration, We found that genotype CC of TNFRSF11A may be a protective factor in KD coronary artery damage (adjusted OR = 0.69 95% CI = 0.49–0.99 P = 0.0429) and is more significant in children with KD ≤ 60 months (adjusted OR = 0.49 95% CI = 0.49–0.93 P = 0.0173).

Conclusion

Our study suggests that TNFRSF11A rs7239667 G > C polymorphism maybe play a protective gene role for the severity of KD coronary artery injury and is related to age, which has not been previously revealed.

Bioinformatics Analysis Identifies Molecular Markers Regulating Development and Progression of Endometriosis and Potential Therapeutic Drugs

Endometriosis, a common disease that presents as polymorphism, invasiveness, and extensiveness, with clinical manifestations including dysmenorrhea, infertility, and menstrual abnormalities, seriously affects quality of life in women. To date, its underlying etiological mechanism of action and the associated regulatory genes remain unclear. This study aimed to identify molecular markers and elucidate mechanisms underlying the development and progression of endometriosis. Specifically, we downloaded five microarray expression datasets, namely, GSE11691, GSE23339, GSE25628, GSE7305, and GSE105764, from the Gene Expression Omnibus (GEO) database. These datasets, obtained from endometriosis tissues, alongside normal controls, were subjected to in-depth bioinformatics analysis for identification of differentially expressed genes (DEGs), followed by analysis of their function and pathways via gene ontology (GO) and KEGG pathway enrichment analyses. Moreover, we constructed a protein–protein interaction (PPI) network to explore the hub genes and modules, and then applied machine learning algorithms support vector machine-recursive feature elimination and least absolute shrinkage and selection operator (LASSO) analysis to identify key genes. Furthermore, we adopted the CIBERSORTx algorithm to estimate levels of immune cell infiltration while the connective map (CMAP) database was used to identify potential therapeutic drugs in endometriosis. As a result, a total of 423 DEGs, namely, 233 and 190 upregulated and downregulated, were identified. On the other hand, a total of 1,733 PPIs were obtained from the PPI network. The DEGs were mainly enriched in immune-related mechanisms. Furthermore, machine learning and LASSO algorithms identified three key genes, namely, apelin receptor (APLNR), C–C motif chemokine ligand 21 (CCL21), and Fc fragment of IgG receptor IIa (FCGR2A). Furthermore, 16 small molecular compounds associated with endometriosis treatment were identified, and their mechanism of action was also revealed. Taken together, the findings of this study provide new insights into the molecular factors regulating occurrence and progression of endometriosis and its underlying mechanism of action. The identified therapeutic drugs and molecular markers may have clinical significance in early diagnosis of endometriosis.

Cognitive development of children with Kawasaki disease and the parenting stress of their caregivers in Taiwan: a case-control study

OBJECTIVE

Kawasaki disease (KD) is an acute form of febrile vasculitis that occurs in early childhood. The multisystemic vasculitis common in patients with KD may influence blood perfusion in the brain, and thus caregivers of children with KD may feel stress with regard to caring for them. Intravenous immunoglobulin (IVIG) infusion is the standard treatment for acute KD, and the most serious complication of KD is coronary artery aneurysms (coronary artery lesion (CAL)). This study aimed to investigate the relationships between KD heterogeneity and the risk of patients' cognitive impairment or caregivers' parenting stress.

DESIGN

A case-control study with consecutive sampling.

SETTING

A medical centre (Kaohsiung Chang Gung Memorial Hospital, Taiwan).

PARTICIPANTS

This study consisted of 176 patients with KD (mean age: 5.5 years, 60.8% boys) and 85 healthy children (mean age: 6.4 years, 54.1% boys).

PRIMARY AND SECONDARY OUTCOME MEASURES

Based on the children's age, each patient with KD and control subject was administered an assessment using the Mullen Scales of Early Learning or the Wechsler Intelligence Scale, and parenting function of their caregivers was assessed using the Parenting Stress Index (PSI)-Short Form.

RESULTS

We observed no significant differences in any developmental index, cognitive function or parenting stress between patients with KD and controls. Among the children with KD, IVIG administration nor CAL was associated with children's cognitive scores. However, the caregivers of patients who had CAL suffered from greater PSI total scores than those of patients without CAL. Furthermore, the caregivers who had education levels of a master's degree or above showed less parenting stress than those who had an education level of college or lower.

CONCLUSION

Caregivers' education is associated to parenting stress, and caregivers of patients with KD who developed CAL may feel stress about the unpredictable sequela caused by CAL for their children. Such caregivers may require support to fulfil their parenting roles.

Long-Term Hypermethylation of FcγR2B in Leukocytes of Patients with Kawasaki Disease

The Fc gamma receptor family contains several activating receptors and the only inhibitory receptor, FcγR2B. In this study, we investigated the dynamic methylation change of FcγR2B in different stages of Kawasaki disease (KD). We enrolled a total of 116 participants, which included patients with febrile diseases as controls and KD patients. Whole blood cells of KD patients were collected prior to intravenous immunoglobulin (IVIG) treatment (KD1), three to seven days after IVIG (KD2), three weeks after IVIG treatment (KD3), six months after IVIG (KD4), and one year after IVIG treatment (KD5). In total, 76 KD patients provided samples in every stage. Leukocytes of controls were also recruited. We performed DNA extraction and pyrosequencing. FcγR2B methylation levels were higher in KD3 compared to both the controls and KD1. A significantly higher methylation of FcγR2B was found in KD5 when compared with KD1. FcγR2B methylation levels in the IVIG-resistant group were lower than those in the IVIG-responsive group at KD1-3 (p = 0.004, 0.004, 0.005 respectively). This study is the first to report the dynamic change of FcγR2B methylation and to demonstrate long-term hypermethylation one year after disease onset. Hypomethylation of FcγR2B is associated with IVIG resistance.

Phenotype, Susceptibility, Autoimmunity, and Immunotherapy Between Kawasaki Disease and Coronavirus Disease-19 Associated Multisystem Inflammatory Syndrome in Children

Coronavirus disease-19 (COVID-19) in children is usually mild but some are susceptible to a Kawasaki disease (KD)-like multisystem inflammatory syndrome in children (MIS-C) in the convalescent stage, posing a need to differentiate the phenotype, susceptibility, autoimmunity, and immunotherapy between KD and MIS-C, particularly in the upcoming mass vaccination of COVID-19. Patients with MIS-C are prone to gastrointestinal symptoms, coagulopathy, and shock in addition to atypical KD syndrome with fever, mucocutaneous lesions, lymphadenopathy, and/or cardiovascular events. MIS-C manifests KD-like symptoms that alert physicians to early recognize and adopt the KD treatment regimen for patients with MIS-C. MIS-C linked to COVID-19 teaches us infection-associated autoimmune vasculitis and vice versa. Studies on genetic susceptibility have identified certain human leukocyte antigen (HLA) locus and toll-like receptor (TLR) associated with KD and/or COVID-19. Certain HLA subtypes, such as HLA-DRB1 and HLA-MICA A4 are associated with KD. HLA-B*46:01 is proposed to be the risk allele of severe COVID-19 infection, and blood group O type is a protective factor of COVID-19. The autoimmune vasculitis of KD, KD shock syndrome (KDSS), or MIS-C is mediated by a genetic variant of HLA, FcγR, and/or antibody-dependent enhancement (ADE) resulting in hyperinflammation with T helper 17 (Th17)/Treg imbalance with augmented Th17/Th1 mediators: interleukin-6 (IL-6), IL-10, inducible protein-10 (IP-10), Interferon (IFNγ), and IL-17A, and lower expression of Treg-signaling molecules, FoxP3, and transforming growth factor (TGF-β). There are certain similarities and differences in phenotypes, susceptibility, and pathogenesis of KD, KDSS, and MIS-C, by which a physician can make early protection, prevention, and precision treatment of the diseases. The evolution of immunotherapies for the diseases has shown that intravenous immunoglobulin (IVIG) alone or combined with corticosteroids is the standard treatment for KD, KDSS, and MIS-C. However, a certain portion of patients who revealed a treatment resistance to IVIG or IVIG plus corticosteroids, posing a need to early identify the immunopathogenesis, to protect hosts with genetic susceptibility, and to combat Th17/Treg imbalance by anti-cytokine or pro-Treg for reversal of the hyperinflammation and IVIG resistance. Based on physiological and pathological immunity of the diseases under genetic susceptibility and host milieu conditions, a series of sequential regimens are provided to develop a so-called "Know thyself, enemy (pathogen), and ever-victorious" strategy for the prevention and immunotherapy of KD and/or MIS-C.

Epigenetics in Kawasaki Disease

Kawasaki disease (KD) is a common febrile multisystemic inflammatory illness in children that preferentially affects coronary arteries. Children with KD who develop coronary artery aneurysms have a life-long risk of premature coronary artery disease. Hypothesis of inherent predisposition to KD is supported by epidemiological evidence that suggests increased risk of development of disease in certain ethnicities and in children with a previous history of KD in siblings or parents. However, occurrence of cases in clusters, seasonal variation, and very low risk of recurrence suggests an acquired trigger (such as infections) for the development of illness. Epigenetic mechanisms that modulate gene expression can plausibly explain the link between genetic and acquired predisposing factors in KD. Analysis of epigenetic factors can also be used to derive biomarkers for diagnosis and prognostication in KD. Moreover, epigenetic mechanisms can also help in pharmacogenomics with the development of targeted therapies. In this review, we analysed the available literature on epigenetic factors such as methylation, micro-RNAs, and long non-coding RNAs in KD and discuss how these mechanisms can help us better understand the disease pathogenesis and advance the development of new biomarkers in KD.

Identification of increased expression of activating Fc receptors and novel findings regarding distinct IgE and IgM receptors in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is associated with expression and methylation of Fc gamma receptor genes. We characterized immunoglobulin A (IgA), IgE, IgG, and IgM receptor expression levels in KD.

METHODS

Fc receptor expression levels were characterized using GeneChip Human Transcriptome Array 2.0 (HTA 2.0) with 18 KD patients, 18 non-febrile controls, and 18 febrile controls. Another 48 control individuals and 46 patients with KD were measured using pyrosequencing for the methylation levels.

RESULTS

The mRNA expression levels of FCER1A and FCER2 were significantly lower in KD patients than in non-febrile controls and then rose following treatments with intravenous immunoglobulin (IVIG). Expression levels of FCER1G increased compared to the non-febrile subjects and then subsided after IVIG. FCER1A methylation was significantly lower among KD patients and even lower in KD patients with IVIG resistance. HTA analysis revealed higher mRNA levels of FCAR, FCGR1C, and FCGR2A in KD patients. FCMR mRNA expression levels were significantly lower in KD patients. FCMR expression levels rose after IVIG treatment. After IVIG, FCGR1A, B, and C decreased even lower than the febrile controls.

CONCLUSION

This is the first study indicating that IgA, IgE, IgG, and IgM receptors are associated with KD. We highlighted potential biomarkers related to Fc receptors and their regulation.

Perspective of Immunopathogenesis and Immunotherapies for Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory illness that mostly occurs in children below 5 years of age, with intractable fever, mucocutaneous lesions, lymphadenopathy, and lesions of the coronary artery (CAL). KD is sharing clinical symptoms with systemic inflammatory syndrome in children (MIS-C) which is related to COVID-19. Certain genes are identified to be associated with KD, but the findings usually differ between countries and races. Human Leukocyte Antigen (HLA) allele types and toll-like receptor (TLR) expression are also correlated to KD. The acute hyperinflammation in KD is mediated by an imbalance between augmented T helper 17 (Th17)/Th1 responses with high levels of interleukin (IL)-6, IL-10, IL-17A, IFN-γ, and IP-10, in contrast to reduced Th2/Treg responses with lower IL-4, IL-5, FoxP3, and TGF-β expression. KD has varying phenotypic variations regarding age, gender, intravenous immunoglobulin (IVIG) resistance, macrophage activation and shock syndrome. The signs of macrophage activation syndrome (MAS) can be interpreted as hyperferritinemia and thrombocytopenia contradictory to thrombocytosis in typical KD; the signs of KD with shock syndrome (KDSS) can be interpreted as overproduction of nitric oxide (NO) and coagulopathy. For over five decades, IVIG and aspirin are the standard treatment for KD. However, some KD patients are refractory to IVIG required additional medications against inflammation. Further studies are proposed to delineate the immunopathogenesis of IVIG-resistance and KDSS, to identify high risk patients with genetic susceptibility, and to develop an ideal treatment regimen, such as by providing idiotypic immunoglobulins to curb cytokine storms, NO overproduction, and the epigenetic induction of Treg function.

Polymorphisms in Fc Gamma Receptors and Susceptibility to Malaria in an Endemic Population

Repeated infections by Plasmodium falciparum result in a humoral response that could reduce disease symptoms and prevent the development of clinical malaria. The principal mechanism underlying this humoral response is that immunoglobulin G (IgG) binds directly to the parasites, thus causing their neutralization. However, the action of antibodies alone is not always sufficient to eliminate pathogens from an organism. One key element involved in the recognition of IgG that plays a crucial role in the destruction of the parasites responsible for spreading malaria is the family of Fc gamma receptors. These receptors are expressed on the surface of immune cells. Several polymorphisms have been detected in the genes encoding these receptors, associated with susceptibility or resistance to malaria in different populations. In this review, we describe identified polymorphisms within the family of Fc gamma receptors and the impact of these variations on the response of a host to infection as well as provide new perspectives for the design of an effective vaccine for malaria.

Adjuvant herbal therapy for targeting susceptibility genes to Kawasaki disease: An overview of epidemiology, pathogenesis, diagnosis and pharmacological treatment of Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is a self-limiting acute systemic vasculitis occur mainly in infants and young children under 5 years old. Although the use of acetylsalicylic acid (AAS) in combination with intravenous immunoglobulin (IVIG) remains the standard therapy to KD, the etiology, genetic susceptibility genes and pathogenic factors of KD are still un-elucidated.

PURPOSE

Current obstacles in the treatment of KD include the lack of standard clinical and genetic markers for early diagnosis, possible severe side effect of AAS (Reye's syndrome), and the refractory KD cases with resistance to IVIG therapy, therefore, this review has focused on introducing the current advances in the identification of genetic susceptibility genes, environmental factors, diagnostic markers and adjuvant pharmacological intervention for KD.

RESULTS

With an overall update in the development of KD from different aspects, our current bioinformatics data has suggested CASP3, CD40 and TLR4 as the possible pathogenic factors or diagnostic markers of KD. Besides, a list of herbal medicines which may work as the adjunct therapy for KD via targeting different proposed molecular targets of KD have also been summarized.

CONCLUSION

With the aid of modern pharmacological research and technology, it is anticipated that novel therapeutic remedies, especially active herbal chemicals targeting precise clinical markers of KD could be developed for accurate diagnosis and treatment of the disease.

Interleukin-1 Beta-Mediated Sex Differences in Kawasaki Disease Vasculitis Development and Response to Treatment

OBJECTIVE

Kawasaki disease (KD) is the leading cause of acute vasculitis and acquired heart disease in children in developed countries. Notably, KD is more prevalent in males than females. We previously established a key role for IL (interleukin)-1 signaling in KD pathogenesis, but whether this pathway underlies the sex-based difference in susceptibility is unknown. Approach and Results: The role of IL-1 signaling was investigated in the Lactobacillus casei cell wall extract-induced experimental mouse model of KD vasculitis. Five-week-old male and female mice were injected intraperitoneally with PBS, Lactobacillus caseicell wall extract, or a combination of Lactobacillus caseicell wall extract and the IL-1 receptor antagonist Anakinra. Aortitis, coronary arteritis inflammation score and abdominal aorta dilatation, and aneurysm development were assessed. mRNA-seq (messenger RNA sequencing) analysis was performed on abdominal aorta tissue. Publicly available human transcriptomics data from patients with KD was analyzed to identify sex differences and disease-associated genes. Male mice displayed enhanced aortitis and coronary arteritis as well as increased incidence and severity of abdominal aorta dilatation and aneurysm, recapitulating the increased incidence in males that is observed in human KD. Gene expression data from patients with KD and abdominal aorta tissue of Lactobacillus caseicell wall extract-injected mice showed enhanced Il1b expression and IL-1 signaling genes in males. Although the more severe IL-1β-mediated disease phenotype observed in male mice was ameliorated by Anakinra treatment, the milder disease phenotype in female mice failed to respond.

CONCLUSIONS

IL-1β may play a central role in mediating sex-based differences in KD, with important implications for the use of anti-IL-1β therapies to treat male and female patients with KD.

Hypomethylation of C1q/tumor necrosis factor-related protein-1 promoter region in whole blood and risks for coronary artery aneurysms in Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is characterized as a self-limited systemic vasculitis. C1q/tumor necrosis factor-related protein-1 (CTRP1) had been associated with the occurrence of vasculitis in KD. Methylation at the promoter region of certain genes was reported to be involved in the development process of KD. This study aims to investigate the methylation levels of CTRP1 in KD, as well as, its potential to predict coronary artery aneurysms (CAAs).

METHODS

31 patients with KD and 14 healthy controls (HCs) were recruited into this study. The KD group was further divided into KD with CAA (KD-CAAs) group and KD without NCAAs (KD-NCAAs) group. Methylation levels of CpG sites were determined by MethylTarget sequencing, a method that uses multiple targeted CpG methylation analysis.

RESULTS

The methylation levels of CTRP1 promoter region in the KD group were lower than that in the HC group at all predicted CpG sites, especially at sites 34, 51, 69, 79, 176 and 206. Compared with KD-CAAs group, the methylation levels of almost every CpG sites of CTRP1 were increased in the KD-NCAAs group, with site 69 and 154 found to be strongly related to the occurrence of CAAs.

CONCLUSIONS

The difference in methylation levels of CTRP1 promoter may be involved in the development process of KD, and may be a potential predictive marker for the occurrence of CAAs.

Epigenetic Regulation of Macrophage Marker Expression Profiles in Kawasaki Disease

Kawasaki disease (KD) is a common systemic vasculitides in children younger than 5 years of age. Activated macrophages are key drivers of vascular inflammation in KD. The aim of this study was to examine differences in M1 and M2 macrophage marker expression in patients with KD. Blood samples were obtained from 18 healthy controls and 18 patients with KD at 24 h prior and 21 days after to intravenous immunoglobulin therapy. GeneChip Human Transcriptome Array 2.0 and Illumina HumanMethylation450 BeadChip were used to examined the mRNA expression and corresponding CpG site methylation ratios of 10 M1 surface markers and 15 M2 surface markers. Of the markers examined 2 M1 markers (TLR2, IL2RA) and 8 M2 markers (ARG1, CCR2, TLR1, TLR8, TLR5, MS4A6A, CD36, and MS4A4A) showed increased mRNA expression in the acute phase of KD which decreased after IVIG therapy (P < 0.05). Corresponding CpG sites in the promoter regions these markers were hypomethylated in the acute phase of KD and significantly increased after IVIG therapy. In conclusion, both M1 and M2 markers showed increased mRNA expression in the acute phase of KD. CpG site methylation may be one of the mechanisms governing macrophage polarization in KD.

Lower CMV and EBV Exposure in Children With Kawasaki Disease Suggests an Under-Challenged Immune System

Background: Kawasaki Disease (KD) is a pediatric vasculitis of which the pathogenesis is unclear. The hypothesis is that genetically pre-disposed children develop KD when they encounter a pathogen which remains most often unidentified or pathogen derived factors. Since age is a dominant factor, prior immune status in children could influence their reactivity and hence the acquisition of KD. We hypothesized that systemic immune responses early in life could protect against developing KD. With this study we tested whether the incidence of previous systemic cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection is lower in children with KD compared to healthy age-matched controls. Methods and Results: We compared 86 KD patients with an age-matched control group regarding CMV and EBV VCA IgG measurements (taken before or 9 months after IVIG treatment). We found that both CMV and EBV had an almost 2-fold lower seroprevalence in the KD population than in the control group. Conclusions: We suggest that an under-challenged immune system causes an altered immune reactivity which may affect the response to a pathological trigger causing KD in susceptible children.

Current State of Precision Medicine in Primary Systemic Vasculitides

Precision medicine (PM) is an emerging data-driven health care approach that integrates phenotypic, genomic, epigenetic, and environmental factors unique to an individual. The goal of PM is to facilitate diagnosis, predict effective therapy, and avoid adverse reactions specific for each patient. The forefront of PM is in oncology; nonetheless, it is developing in other fields of medicine, including rheumatology. Recent studies on elucidating the genetic architecture of polygenic and monogenic rheumatological diseases have made PM possible by enabling physicians to customize medical treatment through the incorporation of clinical features and genetic data. For complex inflammatory disorders, the prevailing paradigm is that disease susceptibility is due to additive effects of common reduced-penetrance gene variants and environmental factors. Efforts have been made to calculate cumulative genetic risk score (GRS) and to relate specific susceptibility alleles for use of target therapies. The discovery of rare patients with single-gene high-penetrance mutations informed our understanding of pathways driving systemic inflammation. Here, we review the advances in practicing PM in patients with primary systemic vasculitides (PSVs). We summarize recent genetic studies and discuss current knowledge on the contribution of epigenetic factors and extracellular vesicles (EVs) in disease progression and treatment response. Implementation of PM in PSVs is a developing field that will require analysis of a large cohort of patients to validate data from genomics, transcriptomics, metabolomics, proteomics, and epigenomics studies for accurate disease profiling. This multi-omics approach to study disease pathogeneses should ultimately provide a powerful tool for stratification of patients to receive tailored optimal therapies and for monitoring their disease activity.

Immunomics in Pediatric Rheumatic Diseases

The inherent complexity in the immune landscape of pediatric rheumatic disease necessitates a holistic system approach. Uncertainty in the mechanistic workings and etiological driving forces presents difficulty in personalized treatments. The development and progression of immunomics are well suited to deal with this complexity. Immunomics encompasses a spectrum of biological processes that entail genomics, transcriptomics, epigenomics, proteomics, and cytomics. In this review, we will discuss how various high dimensional technologies in immunomics have helped to grow a wealth of data that provide salient clues and biological insights into the pathogenesis of autoimmunity. Interfaced with critical unresolved clinical questions and unmet medical needs, these platforms have helped to identify candidate immune targets, refine patient stratification, and understand treatment response or resistance. Yet the unprecedented growth in data has presented both opportunities and challenges. Researchers are now facing huge heterogeneous data sets from different origins that need to be integrated and exploited for further data mining. We believe that the utilization and integration of these platforms will help unravel the complexities and expedite both discovery and validation of clinical targets.

Comprehensive analyses of DNA methylation and gene expression profiles of Kawasaki disease

OBJECTIVE

Kawasaki disease (KD) is a childhood febrile vasculitis with unknown etiology. Epigenetic regulation in the gene expression dynamics has become increasingly important in KD. Thus, we performed an integrated analysis of DNA methylation and gene expression data to identify novel molecular mechanisms and key functional genes in KD.

METHODS

DNA methylation (GSE84624) and gene expression (GSE68004) datasets were downloaded from Gene Expression Omnibus. Methylated-differentially expressed genes (mDEGs) were documented as the overlapping genes between the differentially methylated genes (DMGs) in GSE84624 and differentially expressed genes (DEGs) in GSE68004. Functional enrichment analyses of the mDEGs were conducted using DAVID database. Protein-protein interaction (PPI) network was then constructed to obtain the hub genes involved in KD using STRING database.

RESULTS

A total of 1389 DMGs and 1362 DEGs were screened out between KD and control samples. Overlapping of them resulted in four hypermethylated/downregulated and 187 hypomethylated/upregulated genes. These mDEGs were mainly enriched in inflammation response, innate immune response, and blood coagulation, and signaling pathways such as platelet activation, osteoclast differentiation, and chemokine signaling pathway. PPI network analyses identified MAPK14 and PHLPP1 as the hub genes involved in KD, which could distinguish KD from other common pediatric febrile diseases. In addition, the methylation and expression levels of MAPK14 and PHLPP1 were validated in other independent datasets.

CONCLUSION

This study provides an integrated view of interactions among DNA methylation and gene expression in patients with KD. MAPK14 and PHLPP1 are the key genes influenced by methylation and may serve as candidate biomarkers for KD.

Decreased Steroid Hormone Receptor NR4A2 Expression in Kawasaki Disease Before IVIG Treatment

Kawasaki disease (KD) is anacute febrile coronary vasculitis disease in children. In general, this disease can be treated with a single dose of 2 g/kg intravenous immunoglobulin (IVIG). However, the best timing for administering steroid treatment in acute-stage KD is still under debate. In this study, we recruited 174 participants to survey the transcript levels of steroid hormone receptors in KD patients. The chip studies consisted of 18 KD patients that were analyzed before IVIG treatment and at least 3 weeks after IVIG administration, as well as 36 control subjects, using GeneChip® HTA 2.0. Another cohort consisting of 120 subjects was analyzed to validate qRT-PCR. Our microarray study demonstrated significant downregulated expressions of the mRNA levels of NR1A2, RORA, NR4A1-3, THRA, and PPARD in KD patients in comparision to the controls. However, these genes increased considerably in KD patients after IVIG administration. After PCR validation, our data only revealed decreased NR4A2 mRNA expression in the KD patients compared to those of the controls, which increased after they received IVIG treatment. Our study is the first to report the potential effective utilization of steroid treatment in KD. Prior to IVIG treatment, decreased steroid receptors allowed for the reduced treatment role of steroids. However, after IVIG treatment, increased steroid receptors indicate that steroids are effective as a supplementary treatment for KD.

Decreased DNA methyltransferases expression is associated with coronary artery lesion formation in Kawasaki disease

Background: Kawasaki disease (KD) is the most common acute coronary vasculitis to occur in children. Although we have uncovered global DNA hypomethylation in KD, its underlying cause remains uncertain. In this study, we performed a survey of transcript levels of DNA methyltransferases and demethylases in KD patients. Materials and Methods: We recruited 145 participants for this study. The chip studies consisted of 18 KD patients that were analyzed before undergoing intravenous immunoglobulin (IVIG) treatment and at least 3 weeks after IVIG treatment, as well as 36 control subjects, using Affymetrix GeneChip® Human Transcriptome Array 2.0. An additional study of 91 subjects was performed in order to validate real-time quantitative PCR. Results: In our microarray study, the mRNA levels of DNMT1 and DNMT3A were significantly lower while TET2 was higher in acute-stage KD patients compared to the healthy controls. Through PCR validation, we observed that the expression of DNMT1 and TET2 are consistent with the Transcriptome Array 2.0 results. Furthermore, we observed significantly lower DMNT1 mRNA levels following IVIG treatment between those who developed CAL and those who did not. Conclusion: Our findings provide an evidence of DNA methyltransferases and demethylases changes and are among the first report that transient DNA hypomethylation is induced during acute inflammatory phase of Kawasaki disease.

Multiomics analyses identified epigenetic modulation of the S100A gene family in Kawasaki disease and their significant involvement in neutrophil transendothelial migration

Background

Kawasaki disease (KD) is a prevalent pediatric disease worldwide and can cause coronary artery aneurysm as a severe complication. Typically, DNA methylation is thought to repress the expression of nearby genes. However, the cases in which DNA methylation promotes gene expression have been reported. In addition, globally, to what extent DNA methylation affects gene expression and how it contributes to the pathogenesis of KD are not yet well understood.

Methods

To address these important biological questions, we enrolled subjects, collected DNA and RNA samples from the subjects’ total white blood cells, and performed DNA methylation (M450K) and gene expression (HTA 2.0) microarray assays.

Results

By analyzing the variation ratios of CpG beta values (methylation percentage) and gene expression intensities, we first concluded that the CpG markers close (− 1500 bp to + 500 bp) to the transcription start sites had higher variation ratios, reflecting significant regulation capacities. Next, we observed that, globally speaking, gene expression was modestly negatively correlated (correlation rho ≈ − 0.2) with the DNA methylation status of both upstream and downstream CpG markers in the promoter region. Third, we found that specific CpG markers were hypo-methylated in disease samples compared with healthy samples and hyper-methylated in convalescent samples compared with disease samples, promoting and repressing S100A genes’ expressions, respectively. Finally, using an in vitro cell model, we demonstrated that S100A family proteins enhanced leukocyte transendothelial migration in KD.

Conclusions

This is the first study to integrate genome-wide DNA methylation with gene expression assays in KD and showed that the S100A family plays important roles in the pathogenesis of KD.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0557-1) contains supplementary material, which is available to authorized users.

ABCC4 Variants Modify Susceptibility to Kawasaki Disease in a Southern Chinese Population

A previous family-based linkage study revealed that Kawasaki disease (KD) was associated with variations of the ATP-binding cassette subfamily C member 4 (ABCC4) gene in most European populations. However, significant differences exist among ethnic populations in European and Chinese subjects; therefore, whether ABCC4 variants indicate susceptibility to KD in Chinese children is unclear. The purpose of this research was to evaluate correlations between ABCC4 gene polymorphisms and susceptibility to KD in a Southern Chinese population. We genotyped six polymorphisms (rs7986087, rs868853, rs3765534, rs1751034, rs3742106, and rs9561778) in 775 KD patients and 774 healthy controls. Ninety-five percent confidence intervals (95% CIs) and odds ratios (ORs) were used to assess the strength of each association. We found that the rs7986087 T variant genotype was associated with significantly higher susceptibility to KD (adjusted OR = 1.30, 95% CI = 1.05–1.60 for rs7986087 CT/TT). However, the rs868853 T variant genotype was associated with significantly lower susceptibility to KD (adjusted OR = 0.74, 95% CI = 0.59–0.92 for rs868853 CT/CC). Compared with the patients with 0–4 ABCC4 risk genotypes, the patients with 5-6 ABCC4 risk genotypes had a significantly increased risk of KD (adjusted OR = 1.63, 95% CI = 1.07–2.47), and this risk was more significant in the subgroups of females, subjects aged 12–60 months, and individuals with coronary artery lesions. These results indicate that specific single-nucleotide polymorphisms in the ABCC4 gene may increase susceptibility to KD in a Southern Chinese population.

[Research advances in the pathogenesis of familial Kawasaki disease]

Kawasaki disease has become the leading cause of acquired heart disease in children in North America and Japan. The incidence rate of Kawasaki disease varies significantly across regions and races. The first-degree relatives of patients with Kawasaki disease have a significantly higher risk of this disease than the general population. This article reviews the onset of familial Kawasaki disease and possible pathogenesis.

Effectiveness of intravenous immunoglobulin alone and intravenous immunoglobulin combined with high-dose aspirin in the acute stage of Kawasaki disease: study protocol for a randomized controlled trial

BACKGROUND

Kawasaki disease (KD) is an acute febrile systemic vasculitis most commonly seen in children under 5 years old. High-dose aspirin is often administered, but the duration of such treatment varies. Many centers reduce the aspirin dose once the patient is afebrile, even before treating said patient with intravenous immunoglobulin (IVIG). However, a randomized controlled trial regarding high-dose aspirin in the acute stage of KD has not previously been carried out.

METHODS/DESIGN

This trial has been designed as a multi-center, prospective, randomized controlled, evaluator-blinded trial with two parallel groups to determine whether IVIG alone as the primary therapy in acute-stage KD is as effective as IVIG combined with high-dose aspirin therapy. The primary endpoint is defined as coronary artery lesion (CAL) formation at 6-8 weeks. Patients meeting the eligibility criteria are randomly assigned (1:1) to a test group (that receives only IVIG) or a standard group (that receives IVIG plus high-dose aspirin). This clinical trial is conducted at three medical centers in Taiwan.

DISCUSSION

Since high-dose aspirin has significant anti-inflammatory and anti-platelet functions, it does not appear to affect disease outcomes. Furthermore, it can decrease hemoglobin levels. Therefore, we have initiated this randomized controlled trial to evaluate the necessity of high-dose aspirin in the acute stage of KD.

TRIAL REGISTRATION

Kawasaki Disease Center, Kaohsiung Chang Gung Memorial Hospital, Taiwan. ClinicalTrials.gov Identifier: NCT02951234. Release Date: November 3, 2016.

An update on the role of epigenetics in systemic vasculitis

PURPOSE OF REVIEW

The purpose of this review is to discuss recent observations of epigenetic changes related to the complex pathogenesis of systemic vasculitides and their contribution to the field.

RECENT FINDINGS

There have been new observations of epigenetic changes in vasculitis and their potential role in disease pathogenesis in antineutrophil cytoplasmic antibody-associated vasculitis, giant-cell arteritis, Kawasaki disease, Behçet's disease, and IgA vasculitis. Some of this recent work has focused on the efficacy of using DNA methylation and miRNA expression as clinical biomarkers for disease activity and how DNA methylation and histone modifications interact to regulate disease-related gene expression.

SUMMARY

DNA methylation, histone modification, and miRNA expression changes are all fruitful ground for biomarker discovery and therapeutic targets in vasculitis. Current knowledge has provided targeted and suggested effects, but in many cases, has relied upon small cohorts, cosmopolitan cell populations, and limited knowledge of functional interactions. Expanding our knowledge of how these epigenetic mechanisms interact in a disease-specific and cell-specific manner will help to better understand the pathogenesis of systemic vasculitis.

The human blood DNA methylome identifies crucial role of β-catenin in the pathogenesis of Kawasaki disease

Kawasaki disease (KD) is a type of acute febrile vasculitis syndrome and is the most frequent cause of cardiac illness in children under the age of five years old. Although the etiology of KD remains largely unknown, some recent genome-wide studies have indicated that epigenetic factors may be important in its pathogenesis. We enrolled 24 KD patients and 24 non-KD controls in this study to access their DNA methylation status using HumanMethylation450 BeadChips. Another 34 KD patients and 62 control subjects were enrolled for expression validation. Of the 3193 CpG methylation regions with a methylation difference ≥ 20% between KD and controls, 3096 CpG loci revealed hypomehtylation, with only 3% being hypermethylated. Pathway buildup identified 11 networked genes among the hypermethylated regions, including four transcription factors: nuclear factor of activated T-cells 1, v-ets avian erythroblastosis virus E26 oncogene homolog 1, runt related transcription factor 3, and retinoic acid receptor gamma, as well as the activator β-catenin. Ten of these network-selected genes demonstrated a significant decrease in mRNA in KD patients, whereas only CTNNB1 significantly decreased in correlation with coronary artery lesions in KD patients. Furthermore, CTNNB1-silenced THP-1 monocytic cells drastically increased the expression of CD40 and significantly increased the expression of both CD40 and CD40L in cocultured human coronary artery endothelial cells. This study is the first to identify network-based susceptible genes of hypermethylated CpG loci, their expression levels, and the functional impact of β-catenin, which may be involved in both the cause and the development of KD.

Next generation sequencing identifies miRNA-based biomarker panel for lupus nephritis

The symptomatology of lupus nephritis (LN) consists of foamy urine and lower leg edema, as well as such systemic manifestations as oral ulcers, arthralgia/arthritis, and lymphadenopathy. However, these symptoms may appear mild and non-specific. If these symptoms are unrecognized, thus delaying treatment, approximately 10% of LN patients will develop permanent kidney damage and end-stage kidney disease. Therefore, the purpose of this study is to identify a surrogate biomarker for the early detection of LN. In this study, we first adopted next generation sequencing (NGS) in order to screen differential expression levels of microRNA between SLE patients with and without LN. The results of both the NGS and the literature review confirmed the potential of 15 microRNAs through real-time qPCR. We further considered clinical laboratory data for additional analysis. In total, 41 microRNAs demonstrated significant differences through NGS screening. We then verified eight microRNAs from NGS and seven microRNAs from the literature review using the real-time qPCR method in peripheral mononuclear cells. Ultimately, mir-125a-5p, miR-146a-5p, and mir-221-3p were found to be statistically significant not only in the screening study but also in the real-time qPCR verification studies. miR-146a-5p was observed to have a significant correlation with clinical biochemistry markers, as well as to be a surrogate biomarker for the early detection of lupus nephritis. This study is the first to show that the intracellular biomarker miR-146a-5p may serve as a useful specific biomarker for the detection of lupus nephritis among lupus patients in the future, regardless of serum albumin levels and spot urine protein/creatinine ratio.

Lack of association between miR-218 rs11134527 A>G and Kawasaki disease susceptibility

Kawasaki disease (KD) is a type of disease that includes the development of a fever that lasts at least 5 days and involves the clinical manifestation of multicellular vasculitis. KD has become one of the most common pediatric cardiovascular diseases. Previous studies have reported that miR-218 rs11134527 A>G is associated with susceptibility to various cancer risks. However, there is a lack of evidence regarding the relationship between this polymorphism and KD risk. The present study explored the correlation between the miR-218 rs11134527 A>G polymorphism and the risk of KD. We recruited 532 patients with KD and 623 controls to genotype the miR-218 rs11134527 A>G polymorphism with a TaqMan allelic discrimination assay. Our results illustrated that the miR-218 rs11134527 A>G polymorphism was not associated with KD risk. In an analysis stratified by age, sex, and coronary artery lesions, we found only that the risk of KD was significantly decreased for children older than 5 years (GG vs. AA/AG: adjusted OR = 0.26, 95% CI = 0.07–0.94, P=0.041). The present study demonstrated that the miR-218 rs1113452 A>G polymorphism may have an age-related relationship with KD susceptibility that has not previously been revealed.

Epigenetic hypomethylation and upregulation of NLRC4 and NLRP12 in Kawasaki disease

INTRODUCTION

Kawasaki disease (KD) is a type of childhood febrile systemic vasculitis. Inflammasomes control inflammatory signaling and are related with the development of KD. In this study, we performed a survey of transcripts and global DNA methylation levels of inflammasome sensors of NOD-like receptors (NLRs) and the downstream interleukin 1β (IL-1β).

MATERIALS AND METHODS

In this study, for the chip studies, we recruited a total of 18 KD patients, who we analyzed before receiving intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, as well as 36 non-fever controls by Illumina HumanMethylation 450 BeadChip and Affymetrix GeneChip® Human Transcriptome Array 2.0. A separate group of 78 subjects was performed for real-time quantitative PCR validations.

RESULTS

The expressions of mRNA levels of NLRC4, NLRP12, and IL-1β were significantly upregulated in KD patients compared to the controls (p<0.05). Once KD patients underwent IVIG treatment, these genes considerably decreased. In particular, the methylation status of the CpG sites of these genes indicated a significant opposite tendency between the KD patients and the controls. Furthermore, mRNA levels of IL-1β represented a positive correlation with NLRC4 (p=0.002). We also observed that the mRNA levels of NLRP12 were lower in KD patients who developed coronary arterial lesions (p<0.005).

CONCLUSION

This study is among the first to report epigenetic hypomethylation, increased transcripts, and the upregulation of NLRC4, NLRP12 and IL-1β in KD patients. Moreover, a decreased upregulation of NLRP12 was related to coronary arterial lesion formation in KD patients.

HAMP promoter hypomethylation and increased hepcidin levels as biomarkers for Kawasaki disease

Kawasaki disease (KD) is the most common coronary vasculitis to appear in children with anemia and has been associated with elevated plasma hepcidin levels. We recruited a total of 241 cases, including 18 KD patients, who were tested both prior to receiving intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, and 18 febrile controls, who were observed in the Illumina HumanMethylation450 BeadChip study for their CpG markers. The remaining cases consisted of another 92 KD patients and 113 controls that were used for validation by pyrosequencing. We performed a genetic functional study using Luciferase assays. A support vector machine (SVM) classification model was adopted to identify KD patients and control subjects. In this study, KD patients clearly demonstrated a significantly epigenetic hypomethylation of HAMP promoter compared to controls. After receiving IVIG treatment, the hypomethylation status in KD patients was restored, and we observed a significant opposite tendency between the DNA methylation of target CpG sites (cg23677000 and cg04085447) and the hepcidin level. Furthermore, reporter gene assays were used to detect target CpG sites, the methylation of which displayed decreased levels of HAMP gene expression. Of particular note, we developed a SVM classification model with a 90.9% sensitivity, a 91.9% specificity, and 0.94 auROC in the training set. An independent blind cohort also had good performance (96.1% sensitivity and 89.7% specificity). In this study, we demonstrate HAMP promoter hypomethylation, which upregulates hepcidin expression in KD patients. Furthermore, the reliability and robustness of our SVM classification model can accurately serve as KD biomarkers.

The effect of FcγRIIA and FcγRIIB on coronary artery lesion formation and intravenous immunoglobulin treatment responses in children with Kawasaki disease

Previous research has found patients with the FcγRIIIB NA1 variant having increased risk of intravenous immunoglobulin (IVIG) resistance in Kawasaki disease (KD). Our previous studies revealed that elevated FcγRIIA expression correlated with the susceptibility of KD patients. We conducted this research to determine whether and how Fcγ receptors affect the susceptibility, IVIG treatment response, and coronary artery lesions (CAL) of KD patients. The activating FcγRIIA and inhibitory FcγRIIB methylation levels of seven patients with KD and four control subjects were examined using HumanMethylation27 BeadChip. We enrolled a total of 44 KD patients and 10 control subjects with fevers. We performed real-time RT-PCR to determine the FcγRIIA and FcγRIIB expression levels, as well as a luciferase assay of FcγRIIA. We found a considerable increase in methylation of both FcγRIIA and FcγRIIB in KD patients undergoing IVIG treatment. Promoter methylation of FcγRIIA inhibited reporter activity in K562 cells using luciferase assay. The FcγRIIB mRNA expression levels were not found to increase susceptibility, CAL formation, or IVIG resistance. FcγRIIA mRNA expression levels were significantly higher in IVIG-resistant patients than in those that responded to IVIG during the pre-treatment period. Furthermore, the FcγRIIA/IIB mRNA expression ratio was considerably higher in KD patients with CAL than in those without CAL. FcγRIIA and FcγRIIB both demonstrated increased methylation levels in KD patients that underwent IVIG treatment. FcγRIIA expression influenced the IVIG treatment response of KD patients. The FcγRIIA/IIB mRNA expression ratio was greater in KD patients with CAL formation.

Cognitive Development After Kawasaki Disease - Clinical Study and Validation Using a Nationwide Population-Based Cohort

BACKGROUND

This purpose of this study was to investigate whether Kawasaki disease (KD) increases the risk of cognitive impairment. In this clinical study, cognitive profiles were compared between KD patients, control subjects, and a nationwide population-based cohort to determine the potential correlation between KD and a subsequent diagnosis of an intellectual disability.

METHODS AND RESULTS

The clinical study consisted of 168 KD patients (mean age 5.6 years, 62.5% male) and 81 healthy controls (mean age 6.4 years, 54.3% male). The nationwide cohort consisted of 4,286 KD patients and 50,038 controls retrieved from the Taiwan National Health Insurance Research Database between 1996 and 2000. The clinical study sample revealed no significant difference in any developmental index or cognitive function between KD patients and controls across various age groups (P>0.05). In the nationwide cohort, Cox regression analysis showed that a diagnosis of KD did not significantly affect the likelihood of developing an intellectual disability (adjusted hazard ratio 0.87, 95% confidence interval 0.68-1.11).

CONCLUSIONS

Both the clinical data and the population-based cohort consistently demonstrated that KD does not increase a child's risk of future cognitive impairment. Although the outcome of the present study is negative, caregivers and patients with KD can be reassured that KD will have no effect on developmental milestones or cognitive function later in life.

Male-specific association of the FCGR2A His167Arg polymorphism with Kawasaki disease

Kawasaki disease (KD) is an acute systemic vasculitis that can potentially cause coronary artery aneurysms in some children. KD occurs approximately 1.5 times more frequently in males than in females. To identify sex-specific genetic variants that are involved in KD pathogenesis in children, we performed a sex-stratified genome-wide association study (GWAS), using the Illumina HumanOmni1-Quad BeadChip data (249 cases and 1,000 controls) and a replication study for the 34 sex-specific candidate SNPs in an independent sample set (671 cases and 3,553 controls). Male-specific associations were detected in three common variants: rs1801274 in FCGR2A [odds ratio (OR) = 1.40, P = 9.31 × 10-5], rs12516652 in SEMA6A (OR = 1.87, P = 3.12 × 10-4), and rs5771303 near IL17REL (OR = 1.57, P = 2.53 × 10-5). The male-specific association of FCGR2A, but not SEMA6A and IL17REL, was also replicated in a Japanese population (OR = 1.74, P = 1.04 × 10-4 in males vs. OR = 1.22, P = 0.191 in females). In a meta-analysis with 1,461 cases and 5,302 controls, a very strong association of KD with the nonsynonymous SNP rs1801274 (p.His167Arg, previously assigned as p.His131Arg) in FCGR2A was confirmed in males (OR = 1.48, P = 1.43 × 10-7), but not in the females (OR = 1.17, P = 0.055). The present study demonstrates that p.His167Arg, a KD-associated FCGR2A variant, acts as a susceptibility gene in males only. Overall, the gender differences associated with FCGR2A in KD provide a new insight into KD susceptibility.

Screening of differentially expressed genes associated with Kawasaki disease by microarray analysis

Kawasaki disease (KD) is an autoimmune disorder that can induce coronary artery aneurysms, particularly in the case of delayed diagnosis and/or treatment. Early diagnosis is important for treatment and reduces the risk of heart injury. The aim of the present study was to identify differentially expressed genes by comparing the levels of gene expression in human umbilical vein endothelial cells following treatment with plasma from healthy individuals and patients with acute or convalescent KD. Following comparison of the control and acute KD groups, 385 up-regulated and 537 down-regulated genes were identified in the acute KD group. In the convalescent group, 505 and 879 genes were up-regulated and down-regulated, respectively, relative to the control group. Genes involved in the immune system and cell growth factors were up-regulated, while genes functioning in methylation were down-regulated, following treatment with KD plasma. In addition, five potential candidate molecular markers of KD, C-X-C motif chemokine ligand 2 (CXCL2), interleukin (IL) 8, tripartite motif containing 58 (TRIM58), immunoglobulin superfamily member 3 (IGSF3) and runt related transcription factor 1 (RUNX1) were identified by microarray analysis and verified using quantitative polymerase chain reaction. A significant positive correlation was identified between the neutrophil polys and expression levels of four of these candidate genes, including CXCL2, IL8, TRIM58, and IGSF3 (all P<0.01; R²≥0.64). However, only CXCL2 expression was significantly positively correlated with neutrophil polys (P=0.01; R²=0.64) and neutrophil bands (P<0.001; R²=0.73). These results indicate that CXCL2 serves a crucial role in the injury of endothelial cells by KD plasma.

Identifying genetic hypomethylation and upregulation of Toll-like receptors in Kawasaki disease

Kawasaki disease (KD) is an acute febrile systemic vasculitis that occurs in children and is characterized by elevated levels of proinflammatory cytokines. Toll-like receptors (TLRs) serve as the sensor arm of the innate immune system and induce proinflammatory cytokine expressions.

We recruited a total of 18 paired KD patients, before intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, 18 healthy controls, and 18 febrile controls. For TLR genes and their cytosine-phosphate-guanine (CpG) markers, we used Affymetrix GeneChip^® Human Transcriptome Array 2.0 and Illumina HumanMethylation450 BeadChip to evaluate gene expression levels and methylation patterns, respectively.

KD patients demonstrated a significantly differential expression of TLR mRNA levels compared to both the healthy and febrile controls, with only TLR 3 and 7 not differing between the KD patients and the controls. After patients underwent IVIG treatment, the TLR mRNA levels, except for TLR3, decreased significantly in KD patients. In contrast, the methylation status of the CpG sites of TLR1, 2, 4, 6, 8, and 9 demonstrated an opposite tendency between the two stages of both the KD samples and the controls.

TLRs, particularly TLR1, 2, 4, 6, 8, and 9, may stimulate the immunopathogenesis of KD. These results are among the first to use TLRs to prove that a bacterial inflammatory response may trigger KD.

Epigenetic hypomethylation and upregulation of matrix metalloproteinase 9 in Kawasaki disease

Background

Kawasaki disease (KD) is a type of febrile coronary vasculitis occurring in children. Some researchers have suggested that changes in genetic signatures, such as matrix metalloproteinases (MMPs), are critical markers for cardiovascular diseases. This study aims to provide a comprehensive survey of global DNA methylation levels and MMP transcripts of KD patients compared to control subjects.

Materials and Methods

For chips studies, we recruited a total of 18 KD patients, prior to receiving intravenous immunoglobulin (IVIG) and at least 3 weeks after IVIG treatment, as well as 18 healthy and 18 febrile control subjects. We applied Illumina HumanMethylation450 BeadChip and Affymetrix GeneChip® Human Transcriptome Array 2.0 to evaluate their CpG markers and expression levels, respectively. Then we used a separate cohort to carry out real-time quantitative PCR validations of mRNA levels.

Results

The expressions of mRNA levels of MMP-8, -9, and -25 were significantly upregulated in KD patients compared to the healthy and febrile controls. Once KD patients underwent IVIG treatment, these MMPs considerably decreased. In particular, the methylation status of CpG sites of MMP-9 indicated a significant opposite tendency between both stages of not only the KD samples but also the controls. We also observed the mRNA level of MMP-9 to be higher in KD patients with coronary arterial lesion formation.

Conclusion

This study is the first to report epigenetic hypomethylation, an increased MMP-9 transcript, and the upregulation of MMP-9 in KD patients who had formed coronary arterial lesions.

Preventing coronary artery lesions in Kawasaki disease

A form of systemic vasculitis that affects mostly small and medium-sized vessels, Kawasaki disease (KD) is most commonly found in children under the age of 5 years old. Though its etiology is unknown, KD has been the most frequent acquired heart disease in developing countries. Its incidence has increased over recent decades in many centuries, including Japan, Korea, and China. The most severe complications of KD are coronary artery lesions (CAL), including dilation, fistula, aneurysm, arterial remodeling, stenosis, and occlusion. Aneurysm formation has been observed in 20–25% of KD patients that do not receive intravenous immunoglobulin (IVIG) treatment, and in 3–5% that do receive it. Coronary artery dilation has been found in about 30% of KD patients in the acute stage, although mostly in the transient form. Diminishing the occurrence and regression of CAL is a vital part of treating KD. In this review article, I demonstrate the clinical method to prevent CAL formation used at the Kawasaki Disease Center in Taiwan.

Anemia in Kawasaki Disease: Hepcidin as a Potential Biomarker

Kawasaki disease (KD) is an autoimmune-like disease and acute childhood vasculitis syndrome that affects various systems but has unknown etiology. In addition to the standard diagnostic criteria, anemia is among the most common clinical features of KD patients and is thought to have a more prolonged duration of active inflammation. In 2001, the discovery of a liver-derived peptide hormone known as hepcidin began revolutionizing our understanding of anemia’s relation to a number of inflammatory diseases, including KD. This review focuses on hepcidin-induced iron deficiency’s relation to transient hyposideremia, anemia, and disease outcomes in KD patients, and goes on to suggest possible routes of further study.

[Research advances in association between vitamin D and Kawasaki disease and related mechanisms of action]

Vitamin D is an important steroid hormone, which has a wide biological effect and is the protective factor against cardiovascular disease and other diseases. At present, the etiology and pathogenesis of Kawasaki disease (KD) remain unknown, but recent studies have shown that vitamin D insufficiency or deficiency is associated with KD. Vitamin D insufficiency or deficiency may affect KD via its influence on inflammatory response, adipokine, endothelial function, platelet function, and DNA methylation and increase the risk of coronary artery lesions. This article reviews the research advances in the association between vitamin D and KD and possible mechanisms of action.

Major methylation alterations on the CpG markers of inflammatory immune associated genes after IVIG treatment in Kawasaki disease

Background

Kawasaki disease (KD) is an autoimmune disease preferentially attacking children younger than five years worldwide. So far, the principal treatment to KD is the administration of Intravenous immunoglobulin (IVIG). Although DNA methylation plays important regulation roles in diseases, few studies investigated the regulation roles of DNA methylation in KD.

Methods

In this study, we focused not only on the DNA methylation alterations resulted from KD onset but also on DNA methylation alterations resulted from IVIG administration. To do so, we investigated the effects of KD’s onset and IVIG administration on CpG marker’s methylation alterations.

Results

We first found that DNA methylation alterations reflecting disease onset or IVIG administration are contributed mainly by the CpG markers on autosomes. In addition, we also demonstrated that some CpG markers carry methylation alteration among samples, forcing the expression abundance of the downstream genes to be also altered and negatively correlated with methylation profile. Finally, compared with KD’s onset, IVIG administration brings stronger impact on methylation alteration. And, such alterations were conducted mainly by hyper-methylating CpG markers, forcing the corresponding genes to keep lower expression levels. Moreover, the genes regulated by the altered CpG markers with IVIG administration are enriched in the pathways associated with inflammatory immune response.

Conclusions

In summary, our result provides researchers with another way into the regulation mechanism through which IVIG represses excessive inflammatory responses.

Predisposing factors, pathogenesis and therapeutic intervention of Kawasaki disease

Kawasaki disease (KD) is an acute febrile childhood inflammatory disease, associated with coronary artery abnormalities. The disease is believed to result from an aberrant inflammatory response to an infectious trigger in a genetically predisposed individual. KD is associated with an endothelial cell injury as a consequence of T cell activation and cytotoxic effects of various proinflammatory cytokines. Intravenous immunoglobulin (IVIG) infusion and aspirin are the standard treatment of acute KD. However, 10-20% of patients show resistance to IVIG therapy and present higher risk of coronary vasculitis. The relative roles of second IVIG infusion, corticosteroids, calcineurin inhibitors, interleukin-1 antagonists and anti-tumor necrosis factor agents remain uncertain. In this review, we highlight the predisposing factors, pathogenesis and therapeutic intervention of KD, particularly new therapeutics for IVIG-resistant patients.