The role of TGF-β and myofibroblasts in the arteritis of Kawasaki disease

Kawasaki Disease: An update on Genetics and Pathophysiology

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

Platelets in Kawasaki disease: mediators of vascular inflammation

Kawasaki disease, a systemic vasculitis that affects young children and can result in coronary artery aneurysms, is the leading cause of acquired heart disease among children. A hallmark of Kawasaki disease is increased blood platelet counts and platelet activation, which is associated with an increased risk of developing resistance to intravenous immunoglobulin and coronary artery aneurysms. Platelets and their releasate, including granules, microparticles, microRNAs and transcription factors, can influence innate immunity, enhance inflammation and contribute to vascular remodelling. Growing evidence indicates that platelets also interact with immune and non-immune cells to regulate inflammation. Platelets boost NLRP3 inflammasome activation and IL-1β production by human immune cells by releasing soluble mediators. Activated platelets form aggregates with leukocytes, such as monocytes and neutrophils, enhancing numerous functions of these cells and promoting thrombosis and inflammation. Leukocyte-platelet aggregates are increased in children with Kawasaki disease during the acute phase of the disease and can be used as biomarkers for disease severity. Here we review the role of platelets in Kawasaki disease and discuss progress in understanding the immune-effector role of platelets in amplifying inflammation related to Kawasaki disease vasculitis and therapeutic strategies targeting platelets or platelet-derived molecules.

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.

Immune control in Kawasaki disease knowledge mapping: a bibliometric analysis

BACKGROUND

Kawasaki disease is a systemic vascular disease with an unclear pathophysiology that primarily affects children under the age of five. Research on immune control in Kawasaki disease has been gaining attention. This study aims to apply a bibliometric analysis to examine the present and future directions of immune control in Kawasaki disease.

METHODS

By utilizing the themes "Kawasaki disease," "Kawasaki syndrome," and "immune control," the Web of Science Core Collection database was searched for publications on immune control in Kawasaki disease. This bibliometric analysis was carried out using VOSviewers, CiteSpace, and the R package "bibliometrix."

RESULTS

In total, 294 studies on immune control in Kawasaki disease were published in Web of Science Core Collection. The three most significant institutions were Chang Gung University, the University of California San Diego, and Kaohsiung Chang Gung Memorial Hospital. China, the United States, and Japan were the three most important countries. In this research field, Clinical and Experimental Immunology was the top-referred journal, while the New England Journal of Medicine was the most co-cited journal. The Web of Science Core Collection document by McCrindle BW et al. published in 2017 was the most cited reference. Additionally, the author keywords concentrated on "COVID-19," "SARS-CoV-2," and "multisystem inflammatory syndrome in children" in recent years.

CONCLUSION

The research trends and advancements in immune control in Kawasaki disease are thoroughly summarised in this bibliometric analysis, which is the first to do so. The data indicate recent research frontiers and hot directions, making it easier for researchers to study the immune control of Kawasaki disease.

Candesartan Attenuates Vasculitis in a Mouse Model of Kawasaki Disease Induced by Candida albicans Water-Soluble Fraction

BACKGROUND

The standard treatment for Kawasaki disease is immunoglobulin therapy, but the high frequency of coronary sequelae in immunoglobulin-refractory cases indicates a need for further improvement in treatment.

METHODS

Kawasaki disease-like vasculitis was induced in 5-week-old DBA/2 mice by intraperitoneal administration of 0.5 mg Candida albicans water-soluble fraction (CAWS) daily for 5 days followed by daily administration of candesartan, an angiotensin receptor blocker. The vasculitis suppression effect was confirmed histologically and serologically in mice sacrificed at 28 days after the start of candesartan.

RESULTS

The area of inflammatory cell infiltration at the aortic root was 2.4±1.4% in the Control group, 18.1±1.9% in the CAWS group, and 7.1±2.3%, 5.8±1.4%, 7.6±2.4%, and 7.9±5.0% in the CAWS+candesartan 0.125-mg/kg, 0.25-mg/kg, 0.5-mg/kg, and 1.0-mg/kg groups, respectively (p=0.0200, p=0.0122, p=0.0122, and p=0.0200 vs. CAWS, respectively). The low-dose candesartan group also showed significantly reduced inflammatory cell infiltration. A similar trend was confirmed by immunostaining of macrophages and TGFβ receptors. Measurement of the inflammatory cytokines IL-1β, IL-6, and TNF-α confirmed the anti-vasculitis effect of candesartan.

CONCLUSIONS

Candesartan inhibited vasculitis even at clinical doses used in children, making it a strong future candidate as an additional treatment for immunoglobulin-refractory Kawasaki disease.

Multisystem Inflammatory Syndrome in Children and Kawasaki Disease: A Spectrum of Postinfectious Hyperinflammatory Disease

Kawasaki disease and multisystem inflammatory syndrome in children are hyperinflammatory conditions that share similar emerging pathophysiology hypotheses, clinical features, treatment strategies, and outcomes. Although both conditions have key differences, growing evidence suggests that both conditions might be closely related on a larger spectrum of postinfectious autoimmune responses.

Endothelial Cell Response in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children

Although Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share some clinical manifestations, their cardiovascular outcomes are different, and this may be reflected at the level of the endothelial cell (EC). We performed RNA-seq on cultured ECs incubated with pre-treatment sera from KD (n = 5), MIS-C (n = 7), and healthy controls (n = 3). We conducted a weighted gene co-expression network analysis (WGCNA) using 935 transcripts differentially expressed between MIS-C and KD using relaxed filtering (unadjusted p < 0.05, >1.1-fold difference). We found seven gene modules in MIS-C, annotated as an increased TNFα/NFκB pathway, decreased EC homeostasis, anti-inflammation and immune response, translation, and glucocorticoid responsive genes and endothelial-mesenchymal transition (EndoMT). To further understand the difference in the EC response between MIS-C and KD, stringent filtering was applied to identify 41 differentially expressed genes (DEGs) between MIS-C and KD (adjusted p < 0.05, >2-fold-difference). Again, in MIS-C, NFκB pathway genes, including nine pro-survival genes, were upregulated. The expression levels were higher in the genes influencing autophagy (UBD, EBI3, and SQSTM1). Other DEGs also supported the finding by WGCNA. Compared to KD, ECs in MIS-C had increased pro-survival transcripts but reduced transcripts related to EndoMT and EC homeostasis. These differences in the EC response may influence the different cardiovascular outcomes in these two diseases.

Clinical Signs of Kawasaki Disease from the Perspective of Epithelial-to-Mesenchymal Transition Recruiting Erythrocytes: A Literature Review

Kawasaki disease (KD) is a systemic vasculitis affecting children younger than 5 years of age. Early period in life is marked by rapid somatic growth with cell proliferation and immaturity of the immunity with dominant innate immune system. Coronary complications in KD are the most common acquired heart disease in children, yet the diagnosis of KD still depends on the clinical diagnostic criteria. Glossy red lips and conjunctival injection are characteristic signs enabling pediatricians to make the initial diagnosis of KD; however, little is known why these are so characteristic. The diagnostic criteria of KD seem to be scattered in seemingly irrelevant body systems such as the eyes, lips, skin, and heart. KD is classified as a connective tissue disease. Recently, red blood cells (RBCs) have emerged as important modulators in innate immune response. RBCs are reported to participate in extracellular matrix remodeling and upregulating matrix metalloproteinase (MMP) expression in dermal fibroblasts. Also, fibroblast growth factors and microRNAs associated with fibrosis are drawing attention in KD. The cardinal signs of KD appear at the border of muco-cutaneous junction. Head and neck regions are abundant in tissues undergoing epithelial-to-mesenchymal transition (EMT). Interstitial carditis and valve insufficiency as well as coronary arterial lesions may complicate KD, and these lesions present in tissues that originated from epicardial progenitor cells by EMT. Having reviewed the recent research on KD, we presume that the signs of KD present at borders between keratinized and non-keratinized stratified squamous epithelium where the EMT is still ongoing for the rapid somatic growth where RBCs are recruited as an innate immune response and to prevent excessive fibrosis in mucosa. KD presents scarcely in adults with somatic growth and immune maturation completed. In this review, we attempted to explain the reasons for the clinical manifestations of KD and to search for a link among the diagnostic clues in the perspective of EMT during the somatic growth and immune system maturation in children with KD.

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.

Molecular mechanisms of endothelial dysfunction in Kawasaki-disease-associated vasculitis

Kawasaki disease (KD) is an acute, inflammation mediated vasculitis, mainly affecting in children under five, which is consider as the most common coronary artery disease in children. The injuries of coronary arteries would result in dilation or thrombus formation, bringing great threaten to patients. Endothelium, located in the inner surface of coronary artery, serves as the interface between the circulating inflammatory cells and vascular media or adventitia, which is the first target of inflammatory attacks during early stage of KD. A series of studies have determined vascular endothelial cells damages and dysfunction in KD patients. However, current therapeutic strategy is still challenging. So that it is critical to underline the mechanisms of endothelium injuries. In this review, the role of endothelial cells in the pathogenesis of KD and the therapeutic methods for endothelial cells were systematically described.

RNA Sequencing Reveals Beneficial Effects of Atorvastatin on Endothelial Cells in Acute Kawasaki Disease

Background

Damage to the coronary arteries during the acute phase of Kawasaki disease (KD) is linked to inflammatory cell infiltration, myointimal proliferation, and endothelial cell (EC) dysfunction. To understand the response of ECs to KD treatment, we studied the genome‐wide transcriptional changes in cultured ECs incubated with KD sera before and after treatment with or without atorvastatin.

Methods and Results

RNA sequencing of human umbilical vein ECs incubated with pooled sera from patients with acute KD before or after treatment with intravenous immunoglobulin and infliximab revealed differentially expressed genes in interleukin‐1, tumor necrosis factor‐α, and inflammatory cell recruitment pathways. Subacute sera pooled from patients treated with intravenous immunoglobulin, infliximab, and atorvastatin uniquely induced expression of NOS3 , Kruppel like factor ( KLF2 , and KLF4 (promotes EC homeostasis and angiogenesis) and ZFP36 ring finger protein (ZFP36) and suppressor of cytokine signaling 3 (SOCS3) (suppresses inflammation), and suppressed expression of TGFB2 and DKK1 (induces endothelial‐mesenchymal transition) and sphingosine kinase 1 (SPHK1) and C‐X‐C motif chemokine ligand 8 (CXCL8) (induces inflammation).

Conclusions

These results suggest that atorvastatin treatment of patients with acute KD may improve EC health, reduce mediators of inflammation produced by ECs, and block KD‐induced myofibroblast proliferation.

CircRNA-3302 promotes endothelial-to-mesenchymal transition via sponging miR-135b-5p to enhance KIT expression in Kawasaki disease

Endothelial-to-mesenchymal transition (EndMT) is implicated in myofibroblast-like cell-mediated damage to coronary artery wall of Kawasaki disease (KD) patients, which subsequently increases the risk of coronary artery aneurysm. Many circular RNAs (circRNAs) have been reported to be associated with cardiovascular diseases. However, the roles and underlying molecular mechanism of circRNAs in KD-associated EndMT remains indefinite. In this research, we screened out circRNA-3302 from human umbilical vein endothelial cells (HUVECs) treated by sera from healthy controls (HCs) or KD patients via circRNA sequencing (circRNA-seq). In addition, circRNA-3302 upregulation was verified in endothelial cells stimulated by KD serum and pathological KD mice modeled with Candida albicans cell wall extracts (CAWS). Moreover, in vitro experiments demonstrated that overexpression of circRNA-3302 could markedly induce EndMT, and silencing of circRNA-3302 significantly alleviated KD serum-mediated EndMT. To further explore the molecular mechanisms of circRNA-3302 inducing EndMT, RNA sequencing (RNA-seq), a dual-luciferase reporter system, nuclear and extra-nuclear RNA isolation, RT-qPCR and Western blot analyses and so on, were utilized. Our data demonstrated that circRNA-3302 contributed to the KD-associated EndMT via sponging miR-135b-5p to enhance KIT expression. Collectively, our results imply that circRNA-3302 plays an important role in KD-associated EndMT, providing new insights into minimizing the risks of developing coronary artery aneurysms.

Association of SNP (rs1042579) in thrombomodulin gene and plasma thrombomodulin level in North Indian children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is the commonest systemic vasculitis in children. It predisposes to development of coronary artery abnormalities (CAAs). Thrombomodulin (THBD) gene polymorphism rs1042579 is associated with high risk of cerebrovascular diseases. However, association of THBD polymorphism (rs1042579) and plasma thrombomodulin (TM) levels with susceptibility to KD and CAAs remains unclear.

METHODS AND RESULTS

Polymorphism in THBD gene (rs1042579) was analysed in 50 KD patients and 50 age, gender and ethnicity matched controls using Sanger sequencing. Plasma TM levels were measured by ELISA.

RESULTS

Mean plasma TM level (± SD) in KD patients was 2549.41 (± 853.18) pg/ml and in controls was 2298.03 (± 869.14) pg/ml; p = 0.042. Mean plasma TM levels in CC genotype was 2299.98 (± 834.88) pg/ml and in CT/TT genotype was 2837.96 (± 857.14) pg/ml; p = 0.005. Genotyping data did not reveal significant differences in patients with KD as compared to controls (p = 0.25), and in KD patients with and without CAAs (p = 0.407). Odds of finding T allele in cases were 2.07 times greater than in controls (p = 0.093).

CONCLUSIONS

This is the first study from India, and second in the world, that investigates association of THBD gene polymorphism with KD. This is also the first study to assess plasma TM levels in KD patients. Our data show that plasma TM levels were significantly higher in KD patients with CT/TT genotypes. Further, the polymorphism rs1042579 at exon 1 of THBD gene was found to be more common in KD patients than in controls although the difference was not statistically significant.

Circulating microRNAs in patients with aneurysmal dilatation of coronary arteries

To understand the mechanism underlying coronary artery abnormal dilatation (CAAD), the present study identified and compared the expression of circulating microRNAs (miRNAs) in three groups of patients. Group 1 included 20 patients with CAAD, Group 2 included 20 patients with angiographically confirmed coronary artery disease (CAD), and Group 3 included 20 patients with normal coronary arteries (control). miRNAs were isolated from plasma samples and were profiled using PCR arrays and miRCURY LNA Serum/Plasma Focus PCR Panels. The present study demonstrated that the plasma miRNA levels were significantly different in Group 1 compared with in Group 2 and Group 3 (fold change >2 and P<0.05). The comparison of Group 1 with Group 3 identified 21 significantly upregulated and two downregulated miRNAs in patients with CAAD compared with in the control group. Moreover, six upregulated and two downregulated miRNAs were identified in patients with CAD compared with in the controls. The third comparison revealed four upregulated and three downregulated miRNAs in Group 1, when compared with patients with CAD. In conclusion, the present study identified a specific signature of plasma miRNAs, which were upregulated and downregulated in patients with CAAD compared with in patients with CAD and control individuals.

The Th17 Pathway in Vascular Inflammation: Culprit or Consort?

The involvement of IL-17A in autoimmune and inflammatory diseases has prompted the development of therapeutic strategies to block the Th17 pathway. Promising results came from their use in psoriasis and in ankylosing spondylitis. IL-17A acts on various cell types and has both local and systemic effects. Considering the premature mortality observed during chronic inflammatory diseases, IL-17A action on vascular cells was studied. Both in vitro and in vivo results suggest that this cytokine favors inflammation, coagulation and thrombosis and promotes the occurrence of cardiovascular events. These observations led to study the role of IL-17A in diseases characterized by vascular inflammation, namely allograft rejection and vasculitis. Increased circulating levels of IL-17A and histological staining reveal that the Th17 pathway is involved in the pathogenesis of these diseases. Vasculitis treatment faces challenges while the use of steroids has many side effects. Regarding results obtained in giant cell arteritis with IL-6 inhibitors, a cytokine involved in Th17 differentiation, the use of anti-IL-17 is a promising strategy. However, lessons from rheumatoid arthritis and multiple sclerosis must be learnt before targeting IL-17 in vasculitis, which may be culprit, consort or both of them.

Heart Transplant, Kawasaki Disease, and Bone Marrow Transplant: Are There Consequences?

PURPOSE OF REVIEW

This article reviews the current landscape of cardiovascular disease (CVD) risk factors, focusing on dyslipidemia, which contribute to atherosclerosis in three unique populations: youth less than 18 years-of-age with a history of Kawasaki disease, and those who have undergone orthotopic heart and bone marrow transplants.

RECENT FINDINGS

Atherosclerosis, the major cause of CVD, begins in childhood. Acquired and genetic disorders of lipid and lipoprotein metabolism, present at an early age, are major contributors to early precursors of atherosclerosis, which accelerate after age 20. Treatment of the underlying medical condition and optimum management of all risk factors is critical in improving outcomes. Nonetheless, limited data is available to assist clinical decision-making, with the aim of improving outcomes. Atherosclerosis, beginning in childhood, is multifactorial in origin with complex interplay of inflammation, infection, endothelial dysfunction, and dyslipidemia. Future studies are needed to help elucidate the specific roles of disease mechanisms, with an emphasis on early intervention and prediction of subclinical disease. In addition to a heart healthy lifestyle, there may be a role for use of lipid-lowering medications beginning at an early age.

Association of miR-181c/d gene locus rs8108402 C/T polymorphism with susceptibility to Kawasaki disease in Chinese children

BACKGROUND

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology. The rs8108402 C/T single nucleotide polymorphism (SNP) is located in the promoter region of miR-181-c/d gene and the intron of Nanos3 gene. The miR-181 family contributes to the pathogenesis of cardiovascular and inflammatory disorders, while Nanos3 is involved in DNA transcription regulation and cell proliferation. However, no studies have examined the association between miR-181c/d and Nanos3 polymorphisms and the susceptibility and progression of KD.

OBJECTIVE

The purpose of our study is to examine the association of miR-181c/miR-181d/Nanos3 gene locus rs8108402 C/T polymorphism with KD susceptibility, intravenous immunoglobulin (IVIG) responsiveness, and the development of coronary artery lesions (CAL).

METHODS

Peripheral blood specimens from 100 children with KD and 100 healthy children were collected. The polymorphism of rs8108402 C/T was detected using polymerase chain reaction-sequencing-based typing technique.

RESULTS

There were statistically significant differences in C and T allele frequency distributions between the KD group and healthy controls for the polymorphic site rs8108402 C/T (P = 0.002). The distribution of the genotypes CC, CT, and TT also presented statistical significant difference between the KD and control groups (P = 0.003). Compared to the rs8108402 C allele, the T allele was associated with increased KD susceptibility (OR = 2.080, 95% CI = 1.317∼3.283). However, there were no significant associations discovered between the rs8108402 C/T polymorphism and CAL formation or IVIG unresponsiveness in the study.

CONCLUSION

SNP rs8108402 C/T located in the miR-181c/d promoter and Nanos3 intronic region is associated with susceptibility to Kawasaki disease but not with the development of coronary artery lesions or IVIG unresponsiveness in Chinese children.

Falling Through the Cracks: The Current Gap in the Health Care Transition of Patients With Kawasaki Disease: A Scientific Statement From the American Heart Association

Background

Health care transition (HCT) is a period of high vulnerability for patients with chronic childhood diseases, particularly when patients shift from a pediatric to an adult care setting. An increasing number of patients with Kawasaki disease (KD) who develop medium and large coronary artery aneurysms (classified by the American Heart Association according to maximal internal coronary artery diameter Z‐scores ≥5 and ≥10, respectively) are becoming adults and thus undergoing an HCT. However, a poor transition to an adult provider represents a risk of loss to follow‐up, which can result in increasing morbidity and mortality.

Methods and Results

This scientific statement provides a summary of available literature and expert opinion pertaining to KD and HCT of children as they reach adulthood. The statement reviews the existing life‐long risks for patients with KD, explains current guidelines for long‐term care of patients with KD, and offers guidance on assessment and preparation of patients with KD for HCT. The key element to a successful HCT, enabling successful transition outcomes, is having a structured intervention that incorporates the components of planning, transfer, and integration into adult care. This structured intervention can be accomplished by using the Six Core Elements approach that is recommended by the American Academy of Pediatrics, the American Academy of Family Physicians, and the American College of Physicians.

Conclusions

Formal HCT programs for patients with KD who develop aneurysms should be established to ensure a smooth transition with uninterrupted medical care as these youths become adults.

Gasotransmitters: Potential Therapeutic Molecules of Fibrotic Diseases

Fibrosis is defined as the pathological progress of excessive extracellular matrix (ECM), such as collagen, fibronectin, and elastin deposition, as the regenerative capacity of cells cannot satisfy the dynamic repair of chronic damage. The well-known features of tissue fibrosis are characterized as the presence of excessive activated and proliferated fibroblasts and the differentiation of fibroblasts into myofibroblasts, and epithelial cells undergo the epithelial-mesenchymal transition (EMT) to expand the number of fibroblasts and myofibroblasts thereby driving fibrogenesis. In terms of mechanism, during the process of fibrosis, the activations of the TGF-β signaling pathway, oxidative stress, cellular senescence, and inflammatory response play crucial roles in the activation and proliferation of fibroblasts to generate ECM. The deaths due to severe fibrosis account for almost half of the total deaths from various diseases, and few treatment strategies are available for the prevention of fibrosis as yet. Recently, numerous studies demonstrated that three well-defined bioactive gasotransmitters, including nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H₂S), generally exhibited anti-inflammatory, antioxidative, antiapoptotic, and antiproliferative properties. Besides these effects, a number of studies have reported that low-dose exogenous and endogenous gasotransmitters can delay and interfere with the occurrence and development of fibrotic diseases, including myocardial fibrosis, idiopathic pulmonary fibrosis, liver fibrosis, renal fibrosis, diabetic diaphragm fibrosis, and peritoneal fibrosis. Furthermore, in animal and clinical experiments, the inhalation of low-dose exogenous gas and intraperitoneal injection of gaseous donors, such as SNAP, CINOD, CORM, SAC, and NaHS, showed a significant therapeutic effect on the inhibition of fibrosis through modulating the TGF-β signaling pathway, attenuating oxidative stress and inflammatory response, and delaying the cellular senescence, while promoting the process of autophagy. In this review, we first demonstrate and summarize the therapeutic effects of gasotransmitters on diverse fibrotic diseases and highlight their molecular mechanisms in the process and development of fibrosis.

Soluble LR11 as a Novel Biomarker in Acute Kawasaki Disease

BACKGROUND

Intimal smooth muscle cells (SMCs) play an important role in the vasculitis caused by Kawasaki disease (KD). Lipoprotein receptor 11 (LR11) is a member of the low-density lipoprotein receptor family, which is expressed markedly in intimal vascular SMCs and secreted in a soluble form (sLR11). sLR11 has been recently identified as a potential vascular lesion biomarker. sLR11 is reportedly elevated in patients with coronary artery lesions long after KD, but there is no description of sLR11 in acute KD. Our aim was to determine the sLR11 dynamics in acute KD and to assess its usefulness as a biomarker.Methods and Results:106 acute KD patients and 18 age-matched afebrile controls were enrolled. KD patients were classified into the following subgroups: intravenous immunoglobulin (IVIG) responders (n=85) and non-responders (n=21). Serum sLR11 levels before IVIG therapy were higher in non-responders (median, 19.6 ng/mL; interquartile range [IQR], 13.0-24.9 ng/mL) than in controls (11.9 ng/mL, 10.4-14.9 ng/mL, P<0.01) or responders (14.3 ng/mL, 11.7-16.5 ng/mL, P<0.01). Using a cutoff of >17.5 ng/mL, non-responders to initial IVIG therapy were identified with 66.7% sensitivity and 78.8% specificity.

CONCLUSIONS

sLR11 can reflect the state of acute KD and might be a biomarker for patient response to IVIG therapy.

Biomarkers of inflammation and fibrosis in young adults with history of Kawasaki disease

Background

Myocardial histology from autopsies of young adults with giant coronary artery aneurysms following Kawasaki disease (KD) shows bridging fibrosis beyond the territories supplied by the aneurysmal arteries. The etiology of this fibrosis is unknown, but persistent, low-level myocardial inflammation and microcirculatory ischemia are both possible contributing factors. To investigate the possibility of subclinical myocardial inflammation or fibrosis, we measured validated biomarkers in young adults with a remote history of KD.

Methods

We measured plasma calprotectin, galectin-3 (Gal-3), growth differentiation factor-15 (GDF-15), soluble ST2 (sST2), and serum procollagen type 1C-terminal propeptide (P1CP) in 91 otherwise healthy young adults with a remote history of KD and in 88 age-similar, healthy controls. KD subjects were stratified by coronary artery aneurysm (CAA) status and history of remote myocardial infarction (MI).

Results

After correction for multiple testing, calprotectin, Gal-3, and GDF-15 levels were significantly higher in subjects with persistent CAA (n = 26) compared with KD subjects with remodeled CAA (n = 20, p = 0.005, 0.001, 0.0036, respectively). In a multivariable regression model with CA status as the main predictor and adjusting for sex, MI history, and interval from KD onset, CA status was a significant predictor (Persistent CAA vs KD Normal CA) of calprotectin, Gal-3, GDF-15 and sST2 levels (p = 0.004, <0.001, 0.007, and 0.049, respectively).

Conclusions

These results suggest that ongoing inflammation and fibrosis may be occurring in individuals with persistent CAA. Longitudinal follow-up is needed to clarify the clinical significance of these elevated biomarker levels in this patient population that requires life-long monitoring.

Identifying Circulating MicroRNA in Kawasaki Disease by Next-Generation Sequencing Approach

Kawasaki disease (KD) typically occurs in children aged under 5 years and can cause coronary artery lesions (CALs). Early diagnosis and treatment with intravenous immunoglobulin can reduce the occurrence of CALs; therefore, identifying a good biomarker for diagnosing KD is essential. Here, using next-generation sequencing in patients with recurrent KD, those with viral infection, and healthy controls, we identified dysregulated circulating microRNAs as diagnostic biomarkers for KD. Pathway enrichment analysis illustrated the putative role of these miRNAs in KD progression. Their expression levels were validated using real-time polymerase chain reaction (qPCR). Fifteen dysregulated circulating miRNAs (fold changes >2 and <0.5) were differentially expressed in the recurrent KD group compared with the viral infection and control groups. These miRNAs were significantly involved in the transforming growth factor-β, epithelial-mesenchymal transition, and cell apoptosis signaling pathways. Notably, their expression levels were frequently restored after intravenous immunoglobulin treatment. Among the candidates, miR-24-3p expression level was significantly higher in patients with recurrent KD compared with healthy controls or viral infection controls (p < 0.001). Receiver operating characteristic analysis revealed that high miR-24-3p expression levels may be a potential biomarker for KD diagnosis. In conclusion, we identified miR-24-3p significantly higher in KD patients, which may be a potential diagnostic biomarker for KD.

Inhibition of IL-6 in the LCWE Mouse Model of Kawasaki Disease Inhibits Acute Phase Reactant Serum Amyloid A but Fails to Attenuate Vasculitis

Objective

Kawasaki disease (KD) is the most common cause of acquired pediatric heart disease in the developed world. 10% of KD patients are resistant to front-line therapy, and no interventions exist to address secondary complications such as myocardial fibrosis. We sought to identify proteins and pathways associated with disease and anti-IL-1 treatment in a mouse model of KD.

Methods

Vasculitis was induced via Lactobacillus casei cell wall extract (LCWE) injection in 5-week-old male mice. Groups of mice were injected with LCWE alone, LCWE and IL-1 receptor antagonist anakinra, or saline for controls. Upper heart tissue was assessed by quantitative mass spectrometry analysis. Expression and activation of STAT3 was assessed by immunohistochemistry, immunofluorescence and Western blot, and IL-6 expression by RNA-seq and ELISA. A STAT3 small molecular inhibitor and anti-IL-6R antibody were used to evaluate the role of STAT3 and IL-6 in disease development.

Results

STAT3 was highly expressed and phosphorylated in cardiac tissue of LCWE-injected mice, and reduced following anakinra treatment. Il6 and Stat3 gene expression was enhanced in abdominal aorta of LCWE-injected mice and reduced with Anakinra treatment. IL-6 serum levels were enhanced in LCWE-injected mice and normalized by anakinra. However, neither inhibition of STAT3 nor blockade of IL-6 altered disease development.

Conclusion

Proteomic analysis of cardiac tissues demonstrates differential protein expression between KD-like, control and anakinra treated cardiac tissue. STAT3 and IL-6 were highly upregulated with LCWE and normalized by anakinra treatment. However, both STAT3 and IL-6 were dispensable for disease development indicating they may be bystanders of inflammation.

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.

The Impact of Moderate-Dose Acetylsalicylic Acid in the Reduction of Inflammatory Cytokine and Prevention of Complication in Acute Phase of Kawasaki Disease: The Benefit of Moderate-Dose Acetylsalicylic Acid

Background: Acetylsalicylic acid (ASA) is part of the recommended treatment of Kawasaki disease (KD). Controversies remain regarding the optimal dose of ASA. We aimed to evaluate the impact of different doses of ASA on inflammation control while minimizing adverse effects in the acute phase treatment of KD. Methods: The enrolled 323 patients with KD were divided into three groups according to ASA dose: moderate-dose (30–50 mg/kg/day), high-dose (80–100 mg/kg/day), and non-ASA. Results: High-dose ASA group showed a significantly shorter duration of fever from the start of treatment to remission than other groups. Baseline level and delta score of interleukin (IL)-1, IL-6, IL-10, tumor necrosis factor-α, and transforming growth factor β were not statistically different among the groups. The number of patients who received additional treatments in the non-ASA group was more than other groups. Coronary artery dilatation was not significantly different among the groups. One patient with high-dose ASA was diagnosed with Reye syndrome. Conclusion: Different doses of ASA did not show any differences in changes of inflammatory bio-makers and cytokines. However, high-dose ASA showed occurrence of Reye syndrome, and non-ASA showed intravenous immunoglobulin refractoriness. We suggest that moderate-dose ASA may be beneficial for the treatment of patients in the acute phase of KD.

Sudden death of a young adult with coronary artery vasculitis, coronary aneurysms, parvovirus B19 infection and Kawasaki disease

We present a case of a 20-year-old man who suffered from Kawasaki disease (KD) associated with a florid parvovirus infection, and who died suddenly from thrombotic occlusion of the coronary arteries. The autopsy revealed several aneurysms of the coronary arteries, a chronic vasculitis and a myofibroblast proliferation leading to focal luminal narrowing. The inflammatory response as well as the detection of the viral particles by PCR in blood and in the lesional tissue demonstrated a possible cause by Parvovirus infection. The expression of endoglin on endothelial cells of neoangiogenesis indicates the involvement of the TGF-beta pathway, necessary for maintaining chronic inflammation. In addition, a possible connection between the intake of methylphenidate, arteritis and a possible pre-existing heart disease must be discussed. Furthermore, KD must also be considered as a cause of sudden death in the adult population.

A framework for understanding Kawasaki disease pathogenesis

Kawasaki disease (KD) is a common vasculitis of childhood, typically affecting children under the age of five. Despite many aspects of its presentation that bear resemblence to acute infection, no causative infectious agent has been identified despite years of intense scrutiny. Unlike most infections, however, there are significant differences in racial predilection that suggest a strong genetic influence. The inflammatory response in KD specifically targets the coronary arteries, also unusual for an infectious condition. In this review, we discuss recent hypotheses on KD pathogenesis as well as new insights into the innate immune response and mechanisms behind vascular damage. The pathogenesis is complex, however, and remains inadequately understood.

Use of Adjunctive Therapy in Acute Kawasaki Disease in Latin America

Objective: To characterize the use of adjunctive therapy in Kawasaki disease (KD) in Latin America. Methods: The study included 1,418 patients from the Latin American KD Network (REKAMLATINA) treated for KD between January 1, 2009, and May 31, 2017. Results: Of these patients, 1,152 received only a single dose of IVIG, and 266 received additional treatment. Age at onset was similar in both groups (median 2 vs. 2.2 years, respectively). The majority of patients were male (58 vs. 63.9%) and were hospitalized with the first 10 days of fever (85.1 vs. 84.2%). The most common adjunctive therapy administered was steroids for IVIG-resistance, followed by additional doses of IVIG. The use of biologics such as infliximab was limited. KD patients who received adjunctive therapy were more likely to have a lower platelet count and albumin level as well as a higher Z score of the coronary arteries. Conclusion: This is the first report of adjunctive therapies for KD across Latin America. IVIG continues to be the initial and resistance treatment, however, steroids are also used and to a lesser extent, biological therapy such as infliximab. Future studies should address the barriers to therapy in children with acute KD throughout Latin America.

Insights Into Coronary Artery Lesions in Kawasaki Disease

This review summarizes recent advances in understanding the development of coronary arteritis in Kawasaki disease. Kawasaki disease is the most common cause of acquired heart disease among children characterized with coronary artery abnormalities, which can cause myocardial ischemia, infarction, and even death. The pathogenic factors of Kawasaki disease and the pathological process of coronary artery disease are not clear at present, which brings challenges to the prevention and treatment of the disease. The treatment of Kawasaki disease focuses mainly on timely administration of intravenous high doses of immunoglobulin and aspirin. However, there are still some patients who do not respond well to this standard treatment, and its management remains a challenge. As a result, coronary artery lesions still occur in patients and affect their quality of life. In this review, we discuss updated research data of Kawasaki disease coronary artery lesions.

Phase I/IIa Trial of Atorvastatin in Patients with Acute Kawasaki Disease with Coronary Artery Aneurysm

OBJECTIVES

To determine the safety, tolerability, pharmacokinetics, and immunomodulatory effects of a 6-week course of atorvastatin in patients with acute Kawasaki disease with coronary artery (CA) aneurysm (CAA).

STUDY DESIGN

This was a Phase I/IIa 2-center dose-escalation study of atorvastatin (0.125-0.75 mg/kg/day) in 34 patients with Kawasaki disease (aged 2-17 years) with echocardiographic evidence of CAA. We measured levels of the brain metabolite 24(S)-hydroxycholesterol (24-OHC), serum lipids, acute-phase reactants, liver enzymes, and creatine phosphokinase; peripheral blood mononuclear cell populations; and CA internal diameter normalized for body surface area before atorvastatin treatment and at 2 and 6 weeks after initiation of atorvastatin treatment.

RESULTS

A 6-week course of up to 0.75 mg/kg/day of atorvastatin was well tolerated by the 34 subjects (median age, 5.3 years; IQR, 2.6-6.4 years), with no serious adverse events attributable to the study drug. The areas under the curve for atorvastatin and its metabolite were larger in the study subjects compared with those reported in adults, suggesting a slower rate of metabolism in children. The 24-OHC levels were similar between the atorvastatin-treated subjects and matched controls.

CONCLUSIONS

Atorvastatin was safe and well tolerated in our cohort of children with acute Kawasaki disease and CAA. A Phase III efficacy trial is warranted in this patient population, which may benefit from the known anti-inflammatory and immunomodulatory effects of this drug.

Circulating Markers of Inflammation Persist in Children and Adults With Giant Aneurysms After Kawasaki Disease

Background:

The sequelae of Kawasaki disease (KD) vary widely with the greatest risk for future cardiovascular events among those who develop giant coronary artery aneurysms (CAA). We sought to define the molecular signature associated with different outcomes in pediatric and adult KD patients.

Methods:

Molecular profiling was conducted using mass spectrometry–based shotgun proteomics, transcriptomics, and glycomics methods on 8 pediatric KD patients at the acute, subacute, and convalescent time points. Shotgun proteomics was performed on 9 KD adults with giant CAA and matched healthy controls. Plasma calprotectin was measured by ELISA in 28 pediatric KD patients 1 year post-KD, 70 adult KD patients, and 86 healthy adult volunteers.

Results:

A characteristic molecular profile was seen in pediatric patients during the acute disease, which resolved at the subacute and convalescent periods in patients with no coronary artery sequelae but persisted in 2 patients who developed giant CAA. We, therefore, investigated persistence of inflammation in KD adults with giant CAA by shotgun proteomics that revealed a signature of active inflammation, immune regulation, and cell trafficking. Correlating results obtained using shotgun proteomics in the pediatric and adult KD cohorts identified elevated calprotectin levels in the plasma of patients with CAA. Investigation of expanded pediatric and adult KD cohorts revealed elevated levels of calprotectin in pediatric patients with giant CAA 1 year post-KD and in adult KD patients who developed giant CAA in childhood.

Conclusions:

Complex patterns of biomarkers of inflammation and cell trafficking can persist long after the acute phase of KD in patients with giant CAA. Elevated levels of plasma calprotectin months to decades after acute KD and infiltration of cells expressing S100A8 and A9 in vascular tissues suggest ongoing, subclinical inflammation. Calprotectin may serve as a biomarker to inform the management of KD patients following the acute illness.

Biomarkers for Kawasaki Disease: Clinical Utility and the Challenges Ahead

Kawasaki disease (KD) has replaced acute rheumatic fever as the most common cause of acquired heart disease in children in the developed world and is increasingly being recognized from several developing countries. It is a systemic vasculitis with a predilection for coronary arteries. The diagnosis is based on a constellation of clinical findings that appear in a temporal sequence. Quite understandably, this can become a problem in situations wherein the clinical features are not typical. In such situations, it can be very difficult, if not impossible, to arrive at a diagnosis. Several biomarkers have been recognized in children with acute KD but none of these has reasonably high sensitivity and specificity in predicting the course of the illness. A line up of inflammatory, proteomic, gene expression and micro-RNA based biomarkers has been studied in association with KD. The commonly used inflammatory markers e.g. erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and total leucocyte counts (TLC) lack specificity for KD. Proteomic studies are based on the identification of specific proteins in serum, plasma and urine by gel electrophoresis. A host of genetic studies have identified genes associated with KD and some of these genes can predict the course and coronary outcomes in the affected individuals. Most of these tests are in the early stages of their development and some of these can predict the course, propensity to develop coronary artery sequelae, intravenous immunoglobulin (IVIg) resistance and the severity of the illness in a patient. Development of clinical criteria based on these tests will improve our diagnostic acumen and aid in early identification and prevention of cardiovascular complications.

Interleukin 10 and Transforming Growth Factor Beta Polymorphisms as Risk Factors for Kawasaki Disease: A Case-Control Study and Meta-Analysis

BACKGROUND

Alteration in serum expression of Transforming Growth Factor-beta (TGF-β) and IL-10 have been suggested to play a role in the pathogenesis of Kawasaki Disease (KD). Inconsistent reports exist on the association of IL-10 polymorphisms with KD susceptibility and Coronary Artery Aneurysms (CAA).

METHODS

A number of 110 paediatric patients with KD and 140 healthy individuals were recruited to investigate the frequency of Single Nucleotide Polymorphisms (SNPs) of TGF-β C/T at codon 10 (rs1982073), C/G at codon 25 (rs1800471) and IL-10 A/G at -1082 (rs1800896), C/T at -819 (rs1800871) and A/C at -592 (rs1800872) and their respective genotype and haplotypes. A comprehensive search was performed in MEDLINE and SCOPUS using the keywords of interleukin 10, transforming growth factor beta, and Kawasaki disease. Moreover, previous studies investigating the TGF-β and IL-10 polymorphisms in KD were evaluated. Review Manager Version 5.1 Software was used to perform meta-analysis.

RESULTS

There was no significant association between allelic or genotypic variants in the mentioned polymorphisms in TGF-β or IL-10 with KD or CAA. The only significant haplotypic variant was TC variant at codon 10, and 25 of TGF-β polymorphisms were associated with higher risk of KD. Meta-analysis of a total number of 770 patients vs. 1471 healthy controls showed no difference in the frequency of any of the IL-10 genetic variants in KD patients, regardless of the presence of CAA.

CONCLUSION

Polymorphisms of TGF-β or IL-10 are not associated with additional risk for KD in Iranian population. IL-10 polymorphisms at -1082, -819 and -592 positions are not associated with KD, nor do they predict coronary artery aneurysm formation.

Kawasaki disease: guidelines of the Italian Society of Pediatrics, part I - definition, epidemiology, etiopathogenesis, clinical expression and management of the acute phase

The primary purpose of these practical guidelines related to Kawasaki disease (KD) is to contribute to prompt diagnosis and appropriate treatment on the basis of different specialists’ contributions in the field. A set of 40 recommendations is provided, divided in two parts: the first describes the definition of KD, its epidemiology, etiopathogenetic hints, presentation, clinical course and general management, including treatment of the acute phase, through specific 23 recommendations.

Their application is aimed at improving the rate of treatment with intravenous immunoglobulin and the overall potential development of coronary artery abnormalities in KD. Guidelines, however, should not be considered a norm that limits treatment options of pediatricians and practitioners, as treatment modalities other than those recommended may be required as a result of peculiar medical circumstances, patient’s condition, and disease severity or complications.

A critical appraisal of the role of intracellular Ca2+-signaling pathways in Kawasaki disease

Kawasaki disease is a multi-systemic vasculitis that generally occurs in children and that can lead to coronary artery lesions. Recent studies showed that Kawasaki disease has an important genetic component. In this review, we discuss the single-nucleotide polymorphisms in the genes encoding proteins with a role in intracellular Ca²⁺ signaling: inositol 1,4,5-trisphosphate 3-kinase C, caspase-3, the store-operated Ca²⁺-entry channel ORAI1, the type-3 inositol 1,4,5-trisphosphate receptor, the Na⁺/Ca²⁺ exchanger 1, and phospholipase Cß4 and Cß1. An increase of the free cytosolic Ca²⁺ concentration is proposed to be a major factor in susceptibility to Kawasaki disease and disease outcome, but only for polymorphisms in the genes encoding the inositol 1,4,5-trisphosphate 3-kinase C and the Na⁺/Ca²⁺ exchanger 1, the free cytosolic Ca²⁺ concentration was actually measured and shown to be increased. Excessive cytosolic Ca²⁺ signaling can result in hyperactive calcineurin in T cells with an overstimulated nuclear factor of activated T cells pathway, in hypersecretion of interleukin-1ß and tumor necrosis factor-α by monocytes/macrophages, in increased urotensin-2 signaling, and in an overactivation of vascular endothelial cells.

miR‑186, a serum microRNA, induces endothelial cell apoptosis by targeting SMAD6 in Kawasaki disease

Kawasaki disease (KD) is an acute, self‑limited vasculitis that predominantly affects medium‑sized arteries, particularly the coronary arteries. Recent studies have indicated that microRNAs are involved in many diseases, including KD. However, the detailed mechanism remains unclear. The aim of the present study was to explore the role of miR‑186 in KD and potentially discover a new target for KD treatment. The results demonstrated that miR‑186 was upregulated in serum from patients with KD and KD serum could increase miR‑186 transcript levels in endothelial cells (HUVECs). Overexpression of miR‑186 mimic induced HUVEC apoptosis through mitogen‑activated protein kinase (MAPK) activation by targeting and inhibiting SMAD family member 6 (SMAD6). Furthermore, KD serum induced HUVEC apoptosis through miR‑186. In conclusion, the present results suggested that KD serum‑associated miR‑186 has an essential role in endothelial cell apoptosis by activating the MAPK pathway through targeting the SMAD6 gene.

Adjunctive therapies in Kawasaki disease

Despite the administration of intravenous immunoglobulin (IVIg) at a dose of 2 g/kg, approximately 3-5% of children with acute Kawasaki disease (KD) may develop coronary artery aneurysms. IVIg-resistance, defined as recrudescence of fever more than 36 h after IVIg completion, is a risk factor for coronary artery abnormalities. Thus, several adjunctive therapies are being evaluated for use in IVIg-resistant KD patients and in patients with coronary artery abnormalities. In this review the role of some of these adjunctive therapies in treatment of children with KD is discussed.

Urotensin 2 in Kawasaki disease pathogenesis

BackgroundGenetic variation in calcium signaling pathways is associated with Kawasaki disease (KD) susceptibility and coronary artery aneurysms (CAA). Expression quantitative trait locus analysis for KD-associated variants in calcium/sodium channel gene solute carrier family 8 member 1 (SLC8A1) revealed an effect on expression of urotensin 2 (UTS2). We speculated that UTS2 is influenced by genetic variation in SLC8A1 and contributes to disease pathogenesis.MethodsWe measured levels of UTS2 and its receptor in blood and tissues using quantitative reverse transcription-polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical staining.ResultsUTS2 transcript levels were higher in the whole blood of subjects with KD homozygous for three risk alleles in SLC8A1 (P=0.002-0.006). Increased levels of plasma UTS2 varied as a function of SLC8A1 genotype (P=0.008-0.04). UTS2 and UTS2 receptor were expressed in mononuclear inflammatory cells and spindle-shaped cells in the coronary arterial wall of a patient suffering from KD with CAA and in a femoral endarterectomy specimen from an adult patient with peripheral aneurysms following KD in childhood.ConclusionHost genetics influences UTS2 levels, which may contribute to inflammation and cardiovascular damage in KD.

Gain-of-function STAT1 mutations are associated with intracranial aneurysms

Chronic mucocutaneous candidiasis, characterized by persistent or recurrent fungal infections, represents the clinical hallmark in gain-of-function (GOF) signal transducer and activator of transcription 1 (STAT1) mutation carriers. Several cases of intracranial aneurysms have been reported in patients with GOF STAT1 mutation but the paucity of reported cases likely suggested this association still as serendipity. In order to endorse this association, we link the development of intracranial aneurysms with STAT1 GOF mutation by presenting the two different cases of a patient and her mother, and demonstrate upregulated phosphorylated STAT4 and IL-12 receptor β1 upon stimulation in patient's blood cells. We also detected increased transforming growth factor (TGF)-β type 2 receptor expression, particularly in CD14⁺ cells, and a slightly higher phosphorylation rate of SMAD3. In addition, the mother of the patient developed disseminated bacille Calmette-Guérin disease after vaccination, speculating that GOF STAT1 mutations may confer a predisposition to weakly virulent mycobacteria.

Review: Found in Translation: International Initiatives Pursuing Interleukin-1 Blockade for Treatment of Acute Kawasaki Disease

The decision to move forward with three clinical trials of IL-1 blockade for treatment of acute Kawasaki disease is a case study in translational science. These trials were born on the one hand from transcriptome studies of host response during the acute disease coupled with animal model investigations of key immune signaling pathways and, on the other hand, out of clinical desperation to intervene in patients with severe inflammation in the setting of acute Kawasaki disease. The convergence of laboratory science and clinical observations led to the clinical trials described here and serves as a model for how such observations can be translated into new therapies.

miR-483 Targeting of CTGF Suppresses Endothelial-to-Mesenchymal Transition: Therapeutic Implications in Kawasaki Disease

RATIONALE

Endothelial-mesenchymal transition (EndoMT) is implicated in myofibroblast-like cell-mediated damage to the coronary arterial wall in acute Kawasaki disease (KD) patients, as evidenced by positive staining for connective tissue growth factor (CTGF) and EndoMT markers in KD autopsy tissues. However, little is known about the molecular basis of EndoMT involved in KD.

OBJECTIVE

We investigated the microRNA (miRNA) regulation of CTGF and the consequent EndoMT in KD pathogenesis. As well, the modulation of this process by statin therapy was studied.

METHODS AND RESULTS

Sera from healthy children and KD subjects were incubated with human umbilical vein endothelial cells. Cardiovascular disease-related miRNAs, CTGF, and EndoMT markers were quantified using reverse transcriptase quantitative polymerase chain reaction, ELISA, and Western blotting. Compared with healthy controls, human umbilical vein endothelial cell incubated with sera from acute KD patients had decreased miR-483, increased CTGF, and increased EndoMT markers. Bioinformatics analysis followed by functional validation demonstrated that Krüppel-like factor 4 (KLF4) transactivates miR-483, which in turn targets the 3' untranslated region of CTGF mRNA. Overexpression of KLF4 or pre-miR-483 suppressed, whereas knockdown of KLF4 or anti-miR-483 enhanced, CTGF expression in endothelial cells in vitro and in vivo. Furthermore, atorvastatin, currently being tested in a phase I/IIa clinical trial in KD children, induced KLF4-miR-483, which suppressed CTGF and EndoMT in endothelial cells.

CONCLUSIONS

KD sera suppress the KLF4-miR-483 axis in endothelial cells, leading to increased expression of CTGF and induction of EndoMT. This detrimental process in the endothelium may contribute to coronary artery abnormalities in KD patients. Statin therapy may benefit acute KD patients, in part, through the restoration of KLF4-miR-483 expression.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01431105.

Pathogenetic determinants in Kawasaki disease: the haematological point of view

Kawasaki disease is a multisystemic vasculitis that can result in coronary artery lesions. It predominantly affects young children and is characterized by prolonged fever, diffuse mucosal inflammation, indurative oedema of the hands and feet, a polymorphous skin rash and non‐suppurative lymphadenopathy. Coronary artery involvement is the most important complication of Kawasaki disease and may cause significant coronary stenosis resulting in ischemic heart disease. The introduction of intravenous immunoglobulin decreases the incidence of coronary artery lesions to less than 5%. The etiopathogenesis of this disease remains unclear. Several lines of evidence suggest that an interplay between a microbial infection and a genetic predisposition could take place in the development of the disease. In this review, we summarize the state of the art of pathogenetic mechanisms of Kawasaki disease underscoring the relevance of haematological features as a novel field of investigation.

Genetic Variation in the SLC8A1 Calcium Signaling Pathway Is Associated With Susceptibility to Kawasaki Disease and Coronary Artery Abnormalities

Background—

Kawasaki disease (KD) is an acute pediatric vasculitis in which host genetics influence both susceptibility to KD and the formation of coronary artery aneurysms. Variants discovered by genome-wide association studies and linkage studies only partially explain the influence of genetics on KD susceptibility.

Methods and Results—

To search for additional functional genetic variation, we performed pathway and gene stability analysis on a genome-wide association study data set. Pathway analysis using European genome-wide association study data identified 100 significantly associated pathways ( P <5×10 − 4 ). Gene stability selection identified 116 single nucleotide polymorphisms in 26 genes that were responsible for driving the pathway associations, and gene ontology analysis demonstrated enrichment for calcium transport ( P =1.05×10 − 4 ). Three single nucleotide polymorphisms in solute carrier family 8, member 1 ( SLC8A1 ), a sodium/calcium exchanger encoding NCX1, were validated in an independent Japanese genome-wide association study data set (meta-analysis P =0.0001). Patients homozygous for the A (risk) allele of rs13017968 had higher rates of coronary artery abnormalities ( P =0.029). NCX1, the protein encoded by SLC8A1 , was expressed in spindle-shaped and inflammatory cells in the aneurysm wall. Increased intracellular calcium mobilization was observed in B cell lines from healthy controls carrying the risk allele.

Conclusions—

Pathway-based association analysis followed by gene stability selection proved to be a valuable tool for identifying risk alleles in a rare disease with complex genetics. The role of SLC8A1 polymorphisms in altering calcium flux in cells that mediate coronary artery damage in KD suggests that this pathway may be a therapeutic target and supports the study of calcineurin inhibitors in acute KD.

Serum Tenascin-C as a Novel Predictor for Risk of Coronary Artery Lesion and Resistance to Intravenous Immunoglobulin in Kawasaki Disease - A Multicenter Retrospective Study

BACKGROUND

Tenascin-C (TN-C) is an extracellular matrix glycoprotein that is heavily upregulated at sites of inflammation. We conducted a retrospective study to assess the utility of TN-C as a novel biomarker to predict the risk of developing coronary artery lesions (CAL) and resistance to intravenous immunoglobulin (IVIG) in patients with Kawasaki disease (KD).Methods and Results:We collected blood samples of 111 KD patients (IVIG-responder: 89, IVIG-resistant: 22; CAL: 8) and 23 healthy controls, and measured the serum levels of TN-C. TN-C levels on admission were significantly higher in patients than in healthy controls and in patients during convalescence after IVIG administration (69.6 vs. 20.4 vs. 39.7 ng/ml, respectively; P<0.001), and correlated positively with C-reactive protein (P<0.001), neutrophil (percentage; P=0.005), and ALT (P<0.001), and negatively with platelet count (P=0.023) and sodium level (P=0.025). On admission, TN-C levels in patients who later developed CAL were significantly higher than in those without CAL (P=0.010), and significantly higher in IVIG-resistant subjects than in IVIG-responders (P=0.003). The accuracy of TN-C testing for the prediction of IVIG resistance was comparable to that of the Kobayashi score.

CONCLUSIONS

Serum TN-C could be a biomarker for predicting the risk of developing CAL and IVIG resistance during the acute phase of KD. (Circ J 2016; 80: 2376-2381).

Kawasaki Disease

Kawasaki disease is an acute, self-limited vasculitis of unknown etiology that occurs predominantly in infants and children. If not treated early with high-dose intravenous immunoglobulin, 1 in 5 children develop coronary artery aneurysms; this risk is reduced 5-fold if intravenous immunoglobulin is administered within 10 days of fever onset. Coronary artery aneurysms evolve dynamically over time, usually reaching a peak dimension by 6 weeks after illness onset. Almost all the morbidity and mortality occur in patients with giant aneurysms. Risk of myocardial infarction from coronary artery thrombosis is greatest in the first 2 years after illness onset. However, stenosis and occlusion progress over years. Indeed, Kawasaki disease is no longer a rare cause of acute coronary syndrome presenting in young adults. Both coronary artery bypass surgery and percutaneous intervention have been used to treat Kawasaki disease patients who develop myocardial ischemia as a consequence of coronary artery aneurysms and stenosis.

Genetic variants of ADAM17 are implicated in the pathological process of Kawasaki disease and secondary coronary artery lesions via the TGF-β/SMAD3 signaling pathway

Kawasaki disease (KD) is a systemic vasculitis childhood disease frequently complicating coronary artery lesions (CALs). Recently, the gene encoding a disintegrin and metalloprotease 17 (ADAM17) was found to modify vascular pathology in humans by differentially regulating the transforming growth factor-β (TGF-β) signaling pathway, which affects KD/CAL susceptibility. To explore the potential role of ADAM17 in KD occurrence and outcomes, we investigated the association of 28 single nucleotide polymorphisms (SNPs) in ADAM17 and three pathway genes of TGF-β signaling with KD phenotypes in a Han Chinese population, including 392 KD patients and 421 non-KD controls. Three ADAM17 SNPs showed an association with KD risk, which was further confirmed by haplotype analysis. The effect of ADAM17 on KD was also shown by multi-variable logistic regression analysis. In two-locus model analyses with SNPs in ADAM17 and TGF-β signaling pathway genes, stronger compound effects on the risk of KD and secondary CAL formation were observed relative to comparable single SNPs.

CONCLUSION

Our results suggest that ADAM17 contributes to the KD risk and is involved in secondary CAL formation via the TGF-β/SMAD3 signaling pathway. This further enriches our understanding of the importance of the signaling pathway in KD occurrence and outcomes.

WHAT IS KNOWN

• The transforming growth factor (TGF)-β/SMAD3 signaling pathway greatly influences susceptibility to Kawasaki disease (KD) and secondary coronary artery lesions (CALs) and/or the treatment response of intravenous immunoglobulin. • A disintegrin and metalloprotease 17 (ADAM17) effectively reduces TGF-β signaling by cleaving TGF-β receptor type-1, while ADAM17 genetic variants modify human vascular pathology by differentially regulating this signaling although it is unknown whether ADAM17 contributes to KD phenotypes. What is New: • ADAM17 genetic variants were shown to be associated with KD risk, even when excluding the influence of TGF-β signaling pathway genes, suggesting that ADAM17 is an important KD susceptibility-related genetic locus. • The more significant compound effects of two-locus models, combining single nucleotide polymorphisms (SNPs) in ADAM17 and other TGF-β signaling pathway genes including TGFB2 and SMAD3, on KD phenotypes relative to single SNPs suggest that ADAM17 is also involved in secondary CAL formation and confers the risk of KD/CALs via the TGF-β/SMAD3 signaling pathway.

The immunomodulatory effects of intravenous immunoglobulin therapy in Kawasaki disease

The introduction of intravenous immunoglobulin (IVIG) for modulation of inflammation in acute Kawasaki disease was a great therapeutic triumph. However, three decades later, the mechanisms underlying immune regulation by IVIG are only beginning to be revealed. Stimulation of an immature myeloid population of dendritic cells that secretes IL-10 and the elucidation of Fc-specific natural regulatory T cells provide insights into the mechanisms of IVIG. Other potential mechanisms include provision of agent-specific neutralizing antibody, anti-idiotype and anti-cytokine antibodies, blockade of activating Fcγ receptors and stimulation of the inhibitory FcγRIIb receptor. New initiatives must seek to understand the mechanisms of IVIG in order to replace it one day with more affordable and more targeted therapies.

The transcriptional profile of coronary arteritis in Kawasaki disease

Background

Kawasaki Disease (KD) can cause potentially life-threatening coronary arteritis in young children, and has a likely infectious etiology. Transcriptome profiling is a powerful approach to investigate gene expression in diseased tissues. RNA sequencing of KD coronary arteries could elucidate the etiology and the host response, with the potential to improve KD diagnosis and/or treatment.

Methods

Deep RNA sequencing was performed on KD (n = 8) and childhood control (n = 7) coronary artery tissues, revealing 1074 differentially expressed mRNAs. Non-human RNA sequences were subjected to a microbial discovery bioinformatics platform, and microbial sequences were analyzed by Metastats for association with KD.

Results

T lymphocyte activation, antigen presentation, immunoglobulin production, and type I interferon response were significantly upregulated in KD arteritis, while the tumor necrosis factor α pathway was not differentially expressed. Transcripts from known infectious agents were not specifically associated with KD coronary arteritis.

Conclusions

The immune transcriptional profile in KD coronary artery tissues has features of an antiviral immune response such as activated cytotoxic T lymphocyte and type I interferon-induced gene upregulation. These results provide new insights into the pathogenesis of KD arteritis that can guide selection of new immunomodulatory therapies for high-risk KD patients, and provide direction for future etiologic studies.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-2323-5) contains supplementary material, which is available to authorized users.