Kawasaki disease: update on pathogenesis

Multi-Modality Imaging in Vasculitis

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu's arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet's disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis.

Cardiovascular pathology in vasculitis

Vasculitides are diseases that can affect any vessel. When cardiac or aortic involvement is present, the prognosis can worsen significantly. Pathological assessment often plays a key role in reaching a definite diagnosis of cardiac or aortic vasculitis, particularly when the clinical evidence of a systemic inflammatory disease is missing. The following review will focus on the main histopathological findings of cardiac and aortic vasculitides.

Multisystemic Inflammatory Syndrome in Children and Kawasaki Disease: Parallels in Pathogenesis and Treatment

PURPOSE OF REVIEW

Since it first appeared, multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) has been compared to Kawasaki disease (KD). Although there were early parallels between MIS-C and KD, key differences emerged over time. Here, we aim to compare the pathogenesis, clinical presentation, treatment, and outcomes of MIS-C and KD.

RECENT FINDINGS

In this article, we review and compare MIS-C and KD, highlighting differentiating features. We discuss the epidemiological and immunological factors along with clinical and laboratory features which discern MIS-C from KD. We also compare treatment and our understanding of long-term outcomes. Though parallels exist between MIS-C and KD, distinguishing the two is important for clinical management of patients, counseling about natural history, and determining long-term monitoring. While both MIS-C and KD are characterized by profound inflammation and inflammatory vasculopathy, further study is needed to determine whether they are distinct immunopathogenic disorders.

Unexpectedly high incidence of Kawasaki Disease in a Canadian Atlantic Province- an 11-year retrospective descriptive study

BACKGROUND

Kawasaki Disease (KD) is the leading cause of acquired heart disease in children in developed countries with a variable incidence worldwide. Previous studies reported an unexpectedly high incidence of KD in the Canadian Atlantic Provinces. The goals of our study were to validate this finding in the province of Nova Scotia and to carefully review patients' characteristics and disease outcomes.

METHODS

This was a retrospective review of all children < 16 years old from Nova Scotia diagnosed with KD between 2007-2018. Cases were identified using a combination of administrative and clinical databases. Clinical information was collected retrospectively by health record review using a standardized form.

RESULTS

Between 2007-2018, 220 patients were diagnosed with KD; 61.4% and 23.2% met the criteria for complete and incomplete disease, respectively. The annual incidence was 29.6 per 100,000 children < 5 years. The male to female ratio was 1.3:1 and the median age was 3.6 years. All patients diagnosed with KD in the acute phase received intravenous immunoglobulin (IVIG); 23 (12%) were refractory to the first dose. Coronary artery aneurysms were found in 13 (6%) patients and one patient died with multiple giant aneurysms.

CONCLUSION

We have confirmed an incidence of KD in our population which is higher than that reported in Europe and other regions of North America despite our small Asian population. The comprehensive method to capture patients may have contributed to the detection of the higher incidence. The role of local environmental and genetic factors also deserves further study. Increased attention to regional differences in the epidemiology of KD may improve our understanding of this important childhood vasculitis.

Immune and non-immune mechanisms that determine vasculitis and coronary artery aneurysm topography in Kawasaki disease and MIS-C

The overlap between multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) including coronary artery aneurysms (CAA) and broadly shared gastrointestinal and mucocutaneous disease is poorly defined. In this perspective, we highlight common age-related extravascular epicardial microanatomical and immunological factors that might culminate in CAA expression in both MIS-C and KD. Specifically, the coronary vasa vasorum originates outside the major coronary arteries. Widespread inflammation in the epicardial interstitial compartment in shared between KD and MIS-C. Age-related changes in the neonatal and immature coronary vasculature including the impact of coronary artery biomechanical factors including coronary vessel calibre, age-related vessel distensibility, flow, and vessel neurovascular innervation may explain the decreasing CAA frequency from neonates to older children and the virtual absence of CAA in young adults with the MIS-C phenotype. Other KD and MIS-C features including mucocutaneous disease with keratinocyte-related immunopathology corroborate that disease phenotypes are centrally influenced by inflammation originating outside vessel walls but a potential role for primary coronary artery vascular wall inflammation cannot be excluded. Hence, common extravascular originating tissue-specific responses to aetiologically diverse triggers including superantigens may lead to widespread interstitial tissue inflammation characteristically manifesting as CAA development, especially in younger subjects. Given that CAA is virtually absent in adults, further studies are needed to ascertain whether epicardial interstitial inflammation may impact on both coronary artery physiology and cardiac conduction tissue and contribute to cardiovascular disease- a hitherto unappreciated consideration.

Mercury increases IL-1β and IL-18 secretion and intensifies coronary arteritis in an animal model of Kawasaki disease

Kawasaki disease (KD) is a multisystem vasculitis that predominantly targets the coronary arteries in young children. Epidemiological data suggest both environmental and genetic factors contribute to the susceptibility and severity of the disease. Mercury (Hg) is a known environmental pollutant and a Ca²⁺ signaling modulator. Ca²⁺ signaling regulates the activation of NLRP3 inflammasome. Using the Lactobacillus casei cell wall extract (LCWE) induced coronary arteritis mouse model of KD; we studied the effect of mercury on inflammasome activation and its impact on the immunopathogenesis of KD. Mercury enhances the expression of inflammasome activation resulting in caspase-1 mediated secretion of IL-1β and IL-18 cytokines. In vivo, the administration of mercury together with disease inducing LCWE exacerbates disease resulting in increased incidence and severity of coronary arteritis compared to LCWE alone. Mercury can act as a novel danger signal modulating Ca²⁺ signaling to increase IL-1β and IL-18 secretion and intensifies coronary arteritis in an animal model of KD.

Upregulated Expression of IL2RB Causes Disorder of Immune Microenvironment in Patients with Kawasaki Disease

Aims. The clinical diagnosis of Kawasaki disease (KD) is not easy because of many atypical manifestations. This study is aimed at finding potential diagnostic markers and therapeutic targets for KD and analysing their correlation with immune cell infiltrations. Methods. First, we downloaded the KD dataset from the Gene Expression Omnibus (GEO) database and used R software to identify differentially expressed genes (DEGs) and perform functional correlation analysis. Then, CIBERSORT algorithm was used to evaluate immune cell infiltrations in samples. Coexpression analysis between DEGs and infiltrating immune cells was performed to screen the main infiltrating immune cells. Subsequently, the least absolute shrinkage and selection operator (LASSO) logistic regression analysis was used to screen the core genes related to KD. Finally, correlation analysis between the core genes and the main infiltrating immune cells was performed. Results. 327 DEGs were screened out in this study. Among them, 72 shared genes were the category of genes most likely to be disease-causing for they did not change before and after treatment. After analysis, it was found that expression level of IL2RB in KD tissues was significantly upregulated, the number of resting CD4+ memory T cells was decreased, and the decrease was significantly negatively correlated with the upregulated expression of IL2RB. Therefore, it was speculated that the upregulated expression of IL2RB disrupted Th1/Th2 cell differentiation balance, which led to a decrease of resting CD4+ memory T cells and finally caused disorder of immune microenvironment in patients with KD. Conclusions. Upregulated expression of IL2RB leads to disorder of immune microenvironment in patients with KD and eventually causes the occurrence and development of KD. Therefore, IL2RB may serve as a diagnostic marker and potential therapeutic target for KD.

Refractory Kawasaki disease: modified methylprednisolone regimen decreases coronary artery dilatation

BACKGROUND

The use of corticosteroids in Kawasaki disease (KD) is still controversial. The aim of this study was to investigate the safety and effectiveness of modified methylprednisolone (mPSL) regimen as an initial treatment for refractory KD.

METHODS

This is a real-world observational study. We identified refractory KD with a self-developed scoring system. Patients were divided into the intravenous immunoglobulin (IVIG) + mPSL group and the IVIG group. Clinical outcomes and changes in coronary arteries after the treatment during a 12-week period were observed. Propensity-score matching was used to analyze those patients with similar baseline characteristics.

RESULTS

Of a total of 168 patients, 104 patients were assigned into the IVIG group and 64 patients into the IVIG + mPSL group. The therapeutic response rate of the IVIG + mPSL group was significantly higher than that of the IVIG group (98.4 vs 76.0%, P < 0.05). The IVIG + mPSL group had a shorter duration of fever and a higher rate of C-reactive protein decline than the IVIG group (1.17 ± 0.64 vs 1.81 ± 1.16 days; 88.1 vs 83.5%; P < 0.05). The luminal diameter and Z-score of the left circumflex coronary artery (LCX) were significantly smaller and lower in the IVIG + mPSL group than that in the IVIG group at weeks 2 and 12.

CONCLUSIONS

Modified mPSL regimen has minimal side effects. It might improve the initial response to IVIG and decrease the dilation of LCX for refractory KD.

IMPACT

Modified mPSL regimen (2-4 mg/kg/day, divided into 2-3 doses for 3-5 days, then 1 mg/kg/day, once a day for 3-5 days, then oral prednisone was tapered over 3-5 weeks in 5-7 days steps) as an intensive initial treatment can decrease LCX dilation in high-risk IVIG-resistant KD patients. Our self-developed scoring system has been proven validated and can be used to identify high-risk IVIG-resistant KD patients in North China. The present study provides an alternative therapeutic regimen for high-risk refractory KD patients.

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.

Multisystem inflammatory syndrome in children (MIS-C) possibly secondary to COVID-19 mRNA vaccination

Multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 is a postinfectious condition identified during the COVID-19 pandemic with specific Centers for Disease Control and Prevention and WHO criteria. Theoretical concerns have been raised whether MIS-C might also occur after COVID-19 vaccination, as the pathogenesis of MIS-C is not yet entirely understood. We present a woman in her late teens who developed MIS-C after having received two doses of Pfizer BioNTech COVID-19 vaccine 12 weeks prior, in the setting of documented anti-spike SARS-CoV-2 IgG positive, antinucleocapsid SARS-CoV-2 IgG negative, and multiple negative surveillance SARS-CoV-2 PCRs done in the 12-week period prior to development of MIS-C. While vaccination remains safe and critical in controlling the pandemic, it may be considered as a potential trigger for MIS-C in patients with no history of infection. Further surveillance is necessary to determine whether MIS-C will emerge as a confirmed adverse event after COVID-19 vaccination.

Cytokine Cascade in Kawasaki Disease Versus Kawasaki-Like Syndrome

Kawasaki disease (KD) is a medium vessel systemic vasculitis that predominantly occurs in children below five years of age. It is an acute febrile condition in which coronary artery aneurysms and myocarditis are the most common cardiovascular complications. It is most often characterized by hypercytoki-nemia. The etiopathogenesis of KD is not fully understood. The present review synthesizes the recent advances in the pathophysiology and treatment options of KD. According to different studies, the genetic, infections and autoimmunity factors play a major role in pathogenesis. Several susceptibility genes (e.g. caspase 3) and cytokines (e.g. IL-2, IL-4, IL-6, IL-10, IFN-γ and TNF-α) have been identified in KD. Patients with high cytokine levels are predisposed to KD shock syndrome. The importance of respiratory viruses in the pathogenesis of the disease is unclear. Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may induce in children and adults an abnormal systemic inflammatory response. This syndrome shares characteristics with KD. It has been called by many terms like MIS-C (Multisystem Inflammatory Syndrome in Children), PIMS-TS (pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2), hyperinflammatory shock syndrome, cytokine storm (cytokine release syndrome) or simply, Kawasaki-like syndrome. The cytokine’s role in the development of KD or Kawasaki-like syndrome being triggered by COVID-19 is controversial. The presences of the antiendothelial cell autoantibodies (AECAs) together with the newly developed hypothesis of immunothrombosis are considered potential pathogenic mechanisms for KD. In consequence, the diagnosis and treatment of KD and Kawasaki-like syndrome, one of the most common causes of acquired heart disease in developed countries, are challenging without a clearly defined protocol.

A Review of Coronaviruses Associated With Kawasaki Disease: Possible Implications for Pathogenesis of the Multisystem Inflammatory Syndrome Associated With COVID-19

Multisystem Inflammatory Syndrome in Children (MIS-C), representing a new entity in the spectrum of manifestations of COVID-19, bears symptomatic resemblance with Kawasaki Disease (KD). This review explores the possible associations between KD and the human coronaviruses and discusses the pathophysiological similarities between KD and MIS-C and proposes implications for the pathogenesis of MIS-C in COVID-19. Since 2005, when a case-control study demonstrated the association of a strain of human coronavirus with KD, several studies have provided evidence regarding the association of different strains of the human coronaviruses with KD. Thus, the emergence of the KD-like disease MIS-C in COVID-19 may not be an unprecedented phenomenon. KD and MIS-C share a range of similarities in pathophysiology and possibly even genetics. Both share features of a cytokine storm, leading to a systemic inflammatory response and oxidative stress that may cause vasculitis and precipitate multi-organ failure. Moreover, antibody-dependent enhancement, a phenomenon demonstrated in previous coronaviruses, and the possible superantigenic behavior of SARS-CoV-2, possibly may also contribute toward the pathogenesis of MIS-C. Lastly, there is some evidence of complement-mediated microvascular injury in COVID-19, as well as of endotheliitis. Genetics may also represent a possible link between MIS-C and KD, with variations in FcγRII and IL-6 genes potentially increasing susceptibility to both conditions. Early detection and treatment are essential for the management of MIS-C in COVID-19. By highlighting the potential pathophysiological mechanisms that contribute to MIS-C, our review holds important implications for diagnostics, management, and further research of this rare manifestation of COVID-19.

CDCP1 on Dendritic Cells Contributes to the Development of a Model of Kawasaki Disease

The etiology and pathology of Kawasaki disease (KD) remain elusive. Cub domain-containing protein 1 (CDCP1), a cell-surface protein that confers poor prognosis of patients with certain solid tumors, was recently identified as one of the most significantly upregulated genes in SARS-CoV-2-infected children who developed systemic vasculitis, a hallmark of KD. However, a potential role of CDCP1 in KD has not previously been explored. In this study, we found that CDCP1 knockout (KO) mice exhibited attenuated coronary and aortic vasculitis and decreased serum Candida albicans water-soluble fraction (CAWS)-specific IgM/IgG2a and IL-6 concentrations compared with wild-type mice in an established model of KD induced by CAWS administration. CDCP1 expression was not detectable in cardiomyocytes, cardio fibroblasts, or coronary endothelium, but constitutive expression of CDCP1 was observed on dendritic cells (DCs) and was upregulated by CAWS stimulation. CAWS-induced IL-6 production was significantly reduced in CDCP1 KO DCs, in association with impaired Syk-MAPK signaling pathway activation. These novel findings suggest that CDCP1 might regulate KD development by modulating IL-6 production from DCs via the Syk-MAPK signaling pathway.

The "Intermediate" CD14 + CD16 + monocyte subpopulation plays a role in IVIG responsiveness of children with Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is an acute, self-limited febrile illness of unknown cause. Intravenous immunoglobulin (IVIG)-resistance are related to greater risk for permanent cardiac complications. We aimed to determine the correlation between monocytes and the phenotype of KD in relation to IVIG responsiveness in children.

MATERIALS AND METHODS

The study cohort included 62 patients who were diagnosed with KD, 20 non febrile healthy controls (NFC), and 15 other febrile controls (OFC). In all enrolled patients, blood was taken at least 4 times and laboratory tests were performed. In addition, subtypes of monocytes were characterized via flow cytometry.

RESULTS

The numbers of intermediate monocytes were significantly lower in IVIG-resistant group compared to IVIG-responsive group before IVIG infusion (p < 0.0001). After infusion, intermediate monocytes decreased in the responsive group, while a trend of increase was observed in the resistant group. Only intermediate monocytes were significant in logistic regression with adjusted OR of 0.001 and p value of 0.03.

CONCLUSIONS

CD14 + CD16 + intermediate monocyte may play an important role in IVIG responsiveness among KD children. Low starting levels of intermediate monocytes, followed by a dramatic increase post-IVIG infusion during acute phase of KD are associated with IVIG-resistance. Functional studies on intermediate monocyte may help to reveal the pathophysiology.

Multisystem inflammatory syndrome in children and adults (MIS-C/A): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term "Multisystem Inflammatory Syndrome in Children and Adults (MIS-C/A)" to be utilized in the evaluation of adverse events following immunization. The case definition was developed by topic experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2. The format of the Brighton Collaboration was followed, including an exhaustive review of the literature, to develop a consensus definition and defined levels of certainty. The document underwent peer review by the Brighton Collaboration Network and by selected expert external reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated into this final manuscript.

Searching the Staphylococcal Toxic Shock Syndrome Toxin -1 in Septic Children with negative Cultures: A Comparative Study in Tehran, Iran

BACKGROUND

Bacteria induced sepsis is common in infants and children. Staphylococcus aureus produces numerous exotoxins, like staphylococcal Toxic shock syndrome toxin (TSST- 1), which stimulate the immune system by T cell activation and inflammation in various organs. Recent studies suggest that staphylococcal toxins, generally named super antigens (SAgs), may also have a significant role in the pathogenesis of some pediatric disorders especially in the clinical presentation of sepsis and septic shock. This study was carried out in order to compare staphylococcal TSST- 1 (SAgs) in children with sepsis symptoms (and septic shock) with negative blood culture versus a control group.

MATERIALS AND METHODS

This cross-sectional study was conducted during 2 years (2014 -2016) in two referral hospitals (Rasoul Akram and Bahrami hospitals) in Tehran, Iran. We selected 44 children) mean age of 4 years) who were admitted in pediatrics and PICUs wards with sepsis symptoms- /+septic shock. Forty-five children (mean age of 3.9 years) were selected as a control group. All cases with blood samples were examined for TSST-1 (SAgs) by polymerase chain reaction (PCR) method in both case and control groups and results were compared. Data were analyzed by SPSS-16software. Chi-square or Fisher test was used to compare the variables. P-value < 0.05 was considered as a valuable tool.

RESULTS

Positive blood cultures with other bacteria, Streptococcus pneumonia, Haemophilus influenzae, Pseudomonas aeruginosa, Escherichia coli, were detected in 5 cases with negative TSST-1 in blood samples. S.aureus isolated from blood culture was detected in 2 cases with positive TSST- 1.Positive TSST-1 (SAgs) was detected in 6 cases (14%) with negative blood culture for S.aureus; it was significantly higher in cases (14% vs. 2%; P value = 0.05).

CONCLUSION

This study indicates the probable role of TSST-1(SAgs) in the progression of sepsis (and septic shock) in toxic children with negative blood culture for S.aureus. Anti-staphylococcal treatment is immediately required, especially in toxic children with related clinical presentations, even in cases with negative blood cultures. Indeed, the clinical use against SAgs suppressants of downstream cell-destructive events might be helpful.

Update on molecular diversity and multipathogenicity of staphylococcal superantigen toxins

Staphylococcal superantigen (SAg) toxins are the most notable virulence factors associated with Staphylococcus aureus, which is a pathogen associated with serious community and hospital acquired infections in humans and various diseases in animals. Recently, SAg toxins have become a superfamily with 29 types, including staphylococcal enterotoxins (SEs) with emetic activity, SE-like toxins (SEls) that do not induce emesis in primate models or have yet not  been tested, and toxic shock syndrome toxin-1 (TSST-1). SEs and SEls can be subdivided into classical types (SEA to SEE) and novel types (SEG to SElY, SE01, SE02, SEl26 and SEl27). The genes of SAg toxins are located in diverse accessory genetic elements and share certain structural and biological properties. SAg toxins are heat-stable proteins that exhibit pyrogenicity, superantigenicity and capacity to induce lethal hypersensitivity to endotoxin in humans and animals. They have multiple pathogenicities that can interfere with normal immune function of host, increase the chances of survival and transmission of pathogenic bacteria in host, consequently contribute to the occurrence and development of various infections, persistent infections or food poisoning. This review focuses on the following aspects of SAg toxins: (1) superfamily members of classic and novelty discovered staphylococcal SAgs; (2) diversity of gene locations and molecular structural characteristics; (3) biological characteristics and activities; (4) multi-pathogenicity of SAgs in animal and human diseases, including bovine mastitis, swine sepsis, abscesses and skin edema in pig, arthritis and septicemia in poultry, and nosocomial infections and food-borne diseases in humans.

Characterization of circulating immune cells in acute Kawasaki disease suggests exposure to different antigens

Kawasaki disease (KD) is an acute pediatric vasculitis of unknown etiology that can cause coronary artery aneurysms, and is the leading cause of acquired heart disease in children. We studied aspects of the innate and adaptive immune response in 17 acute KD children prior to treatment with intravenous immunoglobulin. Distinct patterns within the innate immune response correlated with specific clinical features. Proinflammatory myeloid dendritic cells (mDC) were abundant in four of 17 (23·5%) subjects who were older and manifested severe inflammation with clinical myocarditis and elevated hepatobiliary enzyme levels. Of the nine subjects with low levels of anti‐inflammatory, tolerogenic mDC, six had enlarged cervical lymph nodes at diagnosis. In contrast, the adaptive immune repertoire varied greatly with no discernible patterns or associations with clinical features. Two subjects with aneurysms had numerous circulating CD8⁺ T cells. Ten subjects showed low CD4⁺ T cell numbers and seven subjects had CD4⁺ T cells in the normal range. CD4⁺ T cells expressed interleukin‐7 receptor (IL‐7R), suggesting repeated antigenic stimulation. Thymic‐derived regulatory T cells (nT_reg) and peripherally induced regulatory T cells (iT_reg) were also enumerated, with the majority having the nT_reg phenotype. Natural killer (NK) and NK T cell numbers were similar across all subjects. Taken together, the results of the immune monitoring suggest that KD may have multiple triggers that stimulate different arms of the innate and adaptive compartment in KD patients. Thus, it is possible that diverse antigens may participate in the pathogenesis of KD.

Immunogenetics of Kawasaki disease

Kawasaki disease (KD) is a medium vessel vasculitis that affects young children. Despite extensive research over the last 50 years, the etiology of KD remains an enigma. Seasonal change in wind patterns was shown to have correlation with the epidemics of KD in Japan. Occurrence of disease in epidemiological clusters, seasonal variation, and a very low risk of recurrence suggest that KD is triggered by an infectious agent. The identification of oligoclonal IgA response in the affected tissues suggests an antigen-driven inflammation. The recent identification of a viral antigen in the cytoplasm of bronchial ciliated epithelium also favors infection as the main trigger for KD. Pointers that suggest a genetic basis of KD include a high disease prevalence in North-East Asian populations, a high risk among siblings, and familial occurrence of cases. Dysregulated innate and adaptive immune responses are evident in the acute stages of KD. In addition to the coronary wall inflammation, endothelial dysfunction and impaired vascular remodeling contribute to the development of coronary artery abnormalities (CAAs) and thrombosis. Genetic aberrations in certain intracellular signaling pathways involving immune effector functions are found to be associated with increased susceptibility to KD and development of coronary artery abnormalities (CAAs). Several susceptible genes have been identified through genome-wide association studies (GWAS) and linkage studies (GWLS). The genes that are studied in KD can be classified under 4 major groups-enhanced T cell activation (ITPKC, ORAI1, STIM1), dysregulated B cell signaling (CD40, BLK, FCGR2A), decreased apoptosis (CASP3), and altered transforming growth factor beta signaling (TGFB2, TGFBR2, MMP, SMAD). The review aims to highlight the role of several genetic risk factors that are linked with the increased susceptibility to KD.

Maternal Autoimmune Disorders and Risk of Kawasaki Disease in Offspring

We assessed the association between maternal autoimmune disorders and offspring risk of Kawasaki disease in a longitudinal cohort of 792 108 newborns. We found that maternal autoimmune disorders, especially autoimmune thyroiditis, may be risk factors for Kawasaki disease in children, particularly young children.

Antibodies and Immunity During Kawasaki Disease

The cause of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology studies support that an infectious disease is involved in at least starting the inflammatory cascade set off during KD. Clues from epidemiology support that humoral immunity can have a protective effect. However, the role of the immune system, particularly of B cells and antibodies, in pathogenesis of KD is still unclear. Intravenous immunoglobulin (IVIG) and other therapies targeted at modulating inflammation can prevent development of coronary aneurysms. A number of autoantibody responses have been reported in children with KD and antibodies have been generated from aneurysmal plasma cell infiltrates. Recent reports show that children with KD have similar plasmablast responses as other children with infectious diseases, further supporting an infectious starting point. As ongoing studies are attempting to identify the etiology of KD through study of antibody responses, we sought to review the role of humoral immunity in KD pathogenesis, treatment, and recovery.

The expression and significance of serum caveolin-1 in patients with Kawasaki disease

We investigated the expression of caveolin-1 (Cav-1) in Kawasaki disease (KD) and analyzed its relationship with coronary artery lesions (CALs). Cav-1 participated in the progression of CAL in KD. A total of 68 children with KD (23 with CALs), age matched with a fever control group (F, n = 28) and a normal control group (N, n = 24) were enrolled in this study. Cav-1 expression was detected using an enzyme-linked immunosorbent assay. The results are the following: (1) Compared with the F and N, Cav-1 expression was significantly increased in the children with KD (P < 0.05); there was no significant difference in Cav-1 between the F and N. (2) The serum level of Cav-1 was significantly higher in children with KD and CALs during the acute phase than in children with KD without CALs (P < 0.05). (3) Serum Cav-1 may be a biomarker that reflects CALs in children with KD based on a receiver operating characteristic (ROC) curve analysis. (4) Those children with KD who were given intravenous immunoglobulin (2 g/kg, 10-12 h) during the acute phase showed decreased expression of Cav-1 compared to the N. Conclusions are as follows: (1) The serum level of Cav-1 during the acute phase of KD increased significantly, while in KD patients with CALs the increase was even greater. (2) Based on our ROC curve analysis, Cav-1 may be a predictor of CALs in children with KD.

Kawasaki Disease Complicated with Cerebral Vasculitis and Severe Encephalitis

We report a case of a 7-year-old boy with Kawasaki disease (KD) complicated with cerebral vasculitis and encephalitis. The patient was admitted with signs of encephalopathy, seizures, and coma. The diagnosis of KD was made on the 2^nd day of hospitalization based on the clinical features (fever >5 days, maculopapular rash, nonpurulent conjunctivitis, fissured lips, and cervical adenopathy). Brain magnetic resonance imaging findings suggested cerebral vasculitis. Treatment with intravenous immunoglobulin was followed by mild improvement. After a single dose of immunoglobulin, pulse methylprednisolone therapy was started resulting in gradual improvement of consciousness and eventual complete motor and cognitive function recovery with regression of brain magnetic resonance lesions. KD can present with marked neurological symptomatology. Therefore, it should be considered in the differential diagnosis of encephalitis and encephalopathy etiologies in children.

Association between maternal age and outcomes in Kawasaki disease patients

BACKGROUND

The etiology of Kawasaki disease (KD) is still unknown; perinatal factors may have role with few studies. This study was aim to survey the perinatal factors and clinical outcome of KD, including coronary artery lesion (CAL) formation and intravenous immunoglobulin (IVIG) treatment response.

METHODS

We enrolled a total of 185 KD patient-caregiver dyads in this study using questionnaires. The questionnaire included two categories: children's characteristics, which consisted of age at disease onset, gender, gestational age at delivery, birth body weight, delivery methods, and breastfeeding status, and caregivers' characteristics, which consisted of parents or not, education levels, maternal age at giving birth, total number of offspring, and family income. We analyzed the association of these factors with CAL formation and IVIG treatment response of KD.

RESULTS

KD patients with CAL formation had a higher maternal age than non-CAL patients (32.49 ± 3.42 vs. 31.01 ± 3.92 years, p = 0.016). We also found that maternal age ≥ 32 years group had a higher rate of having KD patients with CAL (39/81 vs. 24/74, odds ratio 1.935, 95% confidence interval [1.007, 3.718], p = 0.047). The maternal age ≥ 35 years group had a higher rate of having KD patients with IVIG resistance (6/31 vs. 6/116, odds ratio 4.400, 95% confidence interval [1.309, 14.786], p = 0.01). There was no significant difference in either CAL formation or IVIG resistance in KD with regard to patient's age at disease onset, gestational age, birth body weight, delivery methods, breastfeeding, caregiver type, caregivers' education level, total number of offspring, or family income (p > 0.05).

CONCLUSIONS

This study is the first to report that maternal age is significantly associated with CAL formation and IVIG resistance in KD. We hypothesize that a maternal age less than 32 years would benefit KD offspring.

B Cells and Antibodies in Kawasaki Disease

The etiology of Kawasaki disease (KD), the leading cause of acquired heart disease in children, is currently unknown. Epidemiology supports a relationship of KD to an infectious disease. Several pathological mechanisms are being considered, including a superantigen response, direct invasion by an infectious etiology or an autoimmune phenomenon. Treating affected patients with intravenous immunoglobulin is effective at reducing the rates of coronary aneurysms. However, the role of B cells and antibodies in KD pathogenesis remains unclear. Murine models are not clear on the role for B cells and antibodies in pathogenesis. Studies on rare aneurysm specimens reveal plasma cell infiltrates. Antibodies generated from these aneurysmal plasma cell infiltrates showed cross-reaction to intracellular inclusions in the bronchial epithelium of a number of pathologic specimens from children with KD. These antibodies have not defined an etiology. Notably, a number of autoantibody responses have been reported in children with KD. Recent studies show acute B cell responses are similar in children with KD compared to children with infections, lending further support of an infectious disease cause of KD. Here, we will review and discuss the inconsistencies in the literature in relation to B cell responses, specific antibodies, and a potential role for humoral immunity in KD pathogenesis or diagnosis.

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.

[Not Available]

La maladie de Kawasaki, bien connue des pédiatres, est une vascularite multisystémique aiguë touchant les vaisseaux de moyens calibres avec une prédilection pour les artères coronaires. Dans les pays développés, cette maladie est la première cause de cardiopathie acquise chez l’enfant. La physiopathologie de cette maladie est actuellement toujours inconnue, mais il est communément admis qu’un ou plusieurs agents infectieux induisent une réponse inflammatoire inappropriée chez un sujet génétiquement prédisposé. Le diagnostic est clinique et doit être évoqué chez des enfants présentant une fièvre prolongée de plus de cinq jours avec un syndrome inflammatoire biologique. Des critères cliniques d’inflammation cutanéomuqueuse ont été définis par l’American Heart Association en 2004 afin d’établir le diagnostic. Cependant, certains enfants peuvent présenter des formes incomplètes de la maladie surtout lorsque la maladie apparaît à un âge inhabituel. Les symptômes sont proches de certaines pathologies infectieuses de l’enfant comme la scarlatine ou une infection virale rendant le diagnostic difficile. Par ailleurs, un retard au diagnostic ou l’absence de traitement majore le risque de développer des anévrismes coronaires. Les immunoglobulines polyvalentes constituent le traitement de première ligne, avec un taux de succès de l’ordre de 80 %. En cas de non-réponse à cette première ligne de traitement, le recours aux corticoïdes peut être proposé, en association à une deuxième cure d’immunoglobulines, surtout dans les formes de mauvais pronostic. D’autres thérapeutiques comme les anti-tumor necrosis factor alpha ou certains immunosuppresseurs peuvent aussi être employées en cas de résistance aux immunoglobulines, mais doivent être discutées avec une équipe spécialisée.

The association between the miR-146a rs2910164 C>G polymorphism and Kawasaki disease in a southern Chinese population

miR-146a plays a critical role in innate immune and inflammatory responses. Kawasaki disease involves immune-mediated inflammatory responses, which leads to vascular endothelial injury. However, there has been no study on the association between the miR-146a rs2910164 C>G polymorphism and Kawasaki disease risk. We enrolled 532 Kawasaki disease patients and 623 healthy controls from southern Chinese population, and the miR-146a rs2910164 C>G polymorphism was genotyped by the TaqMan method. There was no evidence that this polymorphism was associated with Kawasaki disease. Stratified analysis also showed no significant association. The present study indicates that the miR-146a rs2910164 C>G polymorphism may not be associated with Kawasaki disease in the southern Chinese population. Larger multicenter studies are needed to confirm our conclusions.

Relationship between IL-27 and coronary arterial lesions in children with Kawasaki disease

Kawasaki disease (KD) arises due to the disorder of the inflammation response and faulty immune regulation. Interleukin-27 (IL-27) is a novel cytokine with both pro-inflammatory and anti-inflammatory effects. This study investigated the relationship between serum levels of IL-27, Interleukin-17A (IL-17A), Interleukin-10 (IL-10), Interleukin-6 (IL-6), Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and coronary artery lesions (CALs) in patients with KD. We obtained blood samples from 81 children with KD before intravenous immunoglobulin (IVIG) therapy. Levels of IL-27, IL-17A, IL-10, IL-6, IL-1β and TNF-α were measured in 251 cases, including 4 groups: the normal control group, NC (n = 90), febrile control, FC (n = 80), KD without coronary arteries (n = 41) and KD with coronary arterial lesions (n = 40). White blood cells counts (WBC), red blood cells counts (RBC), hemoglobin, C-reactive protein (CRP), erythrocyte sedimentation rate and procalcitonin (PCT) were tested in all subjects. Levels of IL-27, IL-10, IL-17A, IL-6, IL-1β and TNF-α were significantly elevated, and RBC and hemoglobin significantly decreased in the group of KD group compared with febrile and control groups. IL-27, IL-6, IL-1β and TNF-α serum levels are even higher in KD children with CALs. There was positive relationship between serum levels of IL-27 and WBC, CRP, PCT, IL-10, IL-17A, IL-6 and TNF-α in children with KD. The up-regulation of IL-27 may be closely linked to up-regulation of systemic pro-inflammatory markers in acute KD. Morover, IL-27 may be involved in the development of CALs in acute KD.

Dissecting Kawasaki disease: a state-of-the-art review

Kawasaki disease (KD) is a pediatric vasculitis with coronary artery aneurysms (CAA) as its main complication. The diagnosis is based on the presence of persistent fever and clinical features including exanthema, lymphadenopathy, conjunctival injection, and changes to the mucosae and extremities. Although the etiology remains unknown, the current consensus is that it is likely caused by an (infectious) trigger initiating an abnormal immune response in genetically predisposed children. Treatment consists of high dose intravenous immunoglobulin (IVIG) and is directed at preventing the development of CAA. Unfortunately, 10-20% of all patients fail to respond to IVIG and these children need additional anti-inflammatory treatment. Coronary artery lesions are diagnosed by echocardiography in the acute and subacute phases. Both absolute arterial diameters and z-scores, adjusted for height and weight, are used as criteria for CAA. Close monitoring of CAA is important as ischemic symptoms or myocardial infarction due to thrombosis or stenosis can occur. These complications are most likely to arise in the largest, so-called giant CAA. Apart from the presence of CAA, it is unclear whether KD causes an increased cardiovascular risk due to the vasculitis itself.

CONCLUSION

Many aspects of KD remain unknown, although there is growing knowledge on the etiology, treatment, and development and classification of CAA. Since children with previous KD are entering adulthood, long-term follow-up is increasingly important. What is known: • Kawasaki disease (KD) is a pediatric vasculitis with coronary artery damage as its main complication. • Although KD approaches its 50th birthday since its first description, many aspects of the disease remain poorly understood. What is new: • In recent years, multiple genetic candidate pathways involved in KD have been identified, with recently promising information about the ITPKC pathway. • As increasing numbers of KD patients are reaching adulthood, increasing information is available about the long-term consequences of coronary artery damage and broader cardiovascular risk.

Genome-Wide Association Study Identifies Novel Susceptibility Genes Associated with Coronary Artery Aneurysm Formation in Kawasaki Disease

Kawasaki disease (KD) or Kawasaki syndrome is known as a vasculitis of small to medium-sized vessels, and coronary arteries are predominantly involved in childhood. Generally, 20-25% of untreated with IVIG and 3-5% of treated KD patients have been developed coronary artery lesions (CALs), such as dilatation and aneurysm. Understanding how coronary artery aneurysms (CAAs) are established and maintained in KD patients is therefore of great importance. Upon our previous genotyping data of 157 valid KD subjects, a genome-wide association study (GWAS) has been conducted among 11 (7%) CAA-developed KD patients to reveal five significant genetic variants passed pre-defined thresholds and resulted in two novel susceptibility protein-coding genes, which are NEBL (rs16921209 (P = 7.44 × 10(-9); OR = 32.22) and rs7922552 (P = 8.43 × 10(-9); OR = 32.0)) and TUBA3C (rs17076896 (P = 8.04 × 10(-9); OR = 21.03)). Their known functions have been reported to associate with cardiac muscle and tubulin, respectively. As a result, this might imply their putative roles of establishing CAAs during KD progression. Additionally, various model analyses have been utilized to determine dominant and recessive inheritance patterns of identified susceptibility mutations. Finally, all susceptibility genes hit by significant genetic variants were further investigated and the top three representative gene-ontology (GO) clusters were regulation of cell projection organization, neuron recognition, and peptidyl-threonine phosphorylation. Our results help to depict the potential routes of the pathogenesis of CAAs in KD patients and will facilitate researchers to improve the diagnosis and prognosis of KD in personalized medicine.

[Coronary artery aneurysms probably due to Kawasaki's disease]

We report the case of a young adult admitted to the Abidjan Heart Institute for coronary angiography to explore unstable angina. Coronary angiography showed multiple aneurysms which suggested sequelae of misdiagnosed Kawasaki disease.

Pediatric vasculitis: recognizing multisystemic manifestations at body imaging

Pediatric vasculitides are multisystem diseases that can be diagnostic challenges because of variable clinical manifestations. The clinical manifestation is determined by the size of the affected vessels, organs involved, extent of vascular injury, and underlying pathologic characteristics. Henoch-Schönlein purpura and Kawasaki disease are the two most common subtypes of pediatric vasculitis. Diagnosis of pediatric vasculitis can be difficult, and the outcome can be serious or fatal in the absence of timely intervention. Imaging plays a central role in establishing the diagnosis of vasculitis involving large- and medium-sized vessels, visualizing its vascular and extravascular manifestations, and monitoring the disease course and response to treatment. Although imaging cannot depict the vessel changes of small-vessel vasculitis directly, it can be used to detect tissue damage resulting from vessel inflammation. This article discusses the classification and clinical features of the major pediatric vasculitides. The imaging approach to and nonneurologic findings of major pediatric vasculitis subtypes are reviewed for the pediatric body imager.

Profiles of responses of immunological factors to different subtypes of Kawasaki disease

Background

The responses of immunological factors to different subtypes of Kawasaki disease (KD) remain poorly understood.

Methods

We recruited 388 patients with KD, 160 patients with infectious febrile disease and 85 normal children who served as control subjects. Both the levels and percentages of T lymphocyte subsets, natural killer cells (NK cells) and B cells were analyzed via flow cytometry. The levels of serum IgG, IgM, IgA and C3, C4 were assessed via velocity scatter turbidimetry.

Results

The most significant differences noted between the patients with infectious febrile disease and the normal children were the elevated levels of B cells, C3 and the ratio of CD4/CD8, and the decreased levels of CD8+ T cells and NK cells, as well as the moderate increase in the absolute value of the CD3+ cells. The decreased T cell levels and the elevated B cell levels were helpful in distinguishing typical KD from atypical KD; the elevated T cell levels, the elevated NK cell and B cell levels and the decreased B cell levels were helpful in predicting the effectiveness of IVIG; low C3 and C4 levels were linked with prodromal infections.

Conclusions

Lymphocytes subsets and complement markers may be useful in differentiating among the different subtypes of KD and in helping clinicians understand the pathophysiology of KD.

Th17- and Treg-related cytokine and mRNA expression are associated with acute and resolving Kawasaki disease

BACKGROUND

Kawasaki disease is a vasculitis most commonly afflicting children <5 years of age. Many autoimmune diseases are associated with up-regulation of T helper (Th) 17 cells, and down-regulation Treg cells. Few studies have examined the Th17/Treg expression in Kawasaki disease.

METHODS

Blood samples were obtained from 186 children with Kawasaki disease at 24 h before IVIG therapy, followed by 3 days and 21 days after IVIG therapy. Thirty children with an acute febrile infectious disease and 30 healthy children were obtained as control. Plasma levels of Th17- and Treg-related cytokines including IL-6, IL-17A, IL-10, TGF-β, and mRNA expression levels of RORγt and Foxp3 were tested.

RESULTS

Patients with Kawasaki disease had higher levels of plasma IL-17A (25.35 ± 3.21 vs 7.78 ± 1.78 pg/ml, P < 0.001) and IL-6 (152.29 ± 21.94 vs 38.63 ± 12.40 pg/ml, P < 0.001) when compared to the febrile control group. IVIG resulted in a reduction in IL-6 and IL-17A at both 3 and 21 days after IVIG therapy. FoxP3 levels increased significantly 3 days after IVIG therapy (2.28 ± 0.34 vs 0.88 ± 0.14, P < 0.001). IVIG resistance was associated with higher levels of IL-10 and IL-17A.

CONCLUSION

Kawasaki disease was associated with higher IL-17A and IL-6, a cytokine profile similar to other autoimmune diseases. IVIG therapy resulted in increased expression of Treg-related FoxP3. IVIG resistance was associated with higher levels of IL-10 and IL-17A. Our findings provide further evidence that Kawasaki disease is an autoimmune-like disease.

[A review of Kawasaki disease, a perspective from the articles published in Mexico since January 1977 to May 2012]

Kawasaki disease was described in 1967 by Tomisu Kawasaki. It affects children aged between one and 5 years, and it evolves with fever and small vessel vasculitis, which leads to cardiovascular complications, including coronary aneurisms, myocarditis, valve injuries, pericardial effusion and myocardial infarction; eventually involving many others organs. The etiology actually is not well known, as the exactly pathogenic mechanisms; however, now there are important advances. If the clinical signs and symptoms are identify early and the children received treatment with aspirin and intravenous immunoglobulin, the patients evolves without sequels. The Kawasaki disease is an infrequent disease in Mexico.

Kawasaki disease: pathophysiology, clinical manifestations, and management

Kawasaki Disease, a systemic vasculitis of unknown origin with specific predilection for the coronary arteries, is the most common cause of childhood-acquired heart disease in western countries. Despite its world-wide incidence, the pathophysiology of this enigmatic disease is still under investigation. Diagnosis is made on a clinical basis, with supportive laboratory evidence and imaging. Once identified, timely initiation of treatment is imperative in order to quell the inflammatory response and decrease the incidence of long-term sequelae, specifically coronary artery aneurysms. Finally, longitudinal follow-up should be implemented based on risk stratification and individualized to each patient.

JNK is critical for the development of Candida albicans-induced vascular lesions in a mouse model of Kawasaki disease

BACKGROUND

Kawasaki disease (KD) is the most common systemic vasculitis of unknown etiology in children, and can cause the life-threatening complication of coronary artery aneurysm. Although a novel treatment strategy for patients with KD-caused vascular lesions is eagerly awaited, their molecular pathogenesis remains largely unknown. c-Jun N-terminal kinase (JNK) is a signaling molecule known to have roles in inflammation and tissue remodeling. The aim of this study was to elucidate significant involvement of JNK in the development of vascular lesions in a mouse model of KD.

METHODS AND RESULTS

We injected Candida albicans cell wall extract (CAWE) into 4-week-old C57BL/6 mice. Macroscopically, we found that CAWE caused the development of bulging lesions at coronary artery, carotid artery, celiac artery, iliac artery and abdominal aorta. Histological examination of coronary artery and abdominal aorta in CAWE-treated mice showed marked inflammatory cell infiltration, destruction of elastic lamellae, loss of medial smooth muscle cells and intimal thickening, which are similar to histological features of vascular lesions of patients with KD. To find the role of JNK in lesion formation, we evaluated the effects of JNK inhibitor, SP600125, on abdominal aortic lesions induced by CAWE. Interestingly, treatment with SP600125 significantly decreased the incidence of lesions and also protected against vascular inflammation and tissue destruction histologically, compared with the placebo treatment.

CONCLUSIONS

Our findings suggest that JNK is crucial for the development of CAWE-induced vascular lesions in mice, and potentially represents a novel therapeutic target for KD.

Developments in large and midsize vasculitis

Childhood vasculitis is a complex and fascinating area in pediatric rheumatology that has experienced an unprecedented surge in research, leading to new knowledge over the past several years. Vasculitis is defined as the presence of inflammatory cell infiltration in blood vessel walls, usually with multisystemic involvement. The most frequent forms of vasculitis in childhood are the small-size vasculitides, of which Henoch-Schoenlein Purpura and other leucocytoclastic vasculitis are the best examples, followed by Kawasaki disease, a midsize vasculitis, and Takayasu arteritis, a large-size vasculitis, both of which are topics in this article.

8p22-23-rs2254546 as a susceptibility locus for Kawasaki disease: a case-control study and a meta-analysis

8p22-23-rs2254546 was firstly discovered to be associated with Kawasaki disease (KD) susceptibility by a genome-wide association study. However, only one Chinese replication study has been performed so far. To verify this association in another Chinese population, a hospital-based case-control study in Zhejiang province was conducted followed by an integrated meta-analysis, comprising five case-control studies of 1958 cases, 5615 controls and four transmission disequilibrium tests of 503 trios. In our case-control study, significant associations were observed between GG genotype or GG/GA genotypes of rs2254546 and increased KD risk (OR = 1.86, 95% CI = 1.01-3.41, P = 0.045; OR = 1.83, 95% CI = 1.01-3.33, P = 0.048), compared with AA genotype; however, no significant association was found in allelic model (OR = 1.20, 95% CI = 0.96-1.50, P = 0.117). The meta-analysis further revealed that the G allele was significantly associated with the increased KD risk without evidence of heterogeneity (OR = 1.55, 95% CI = 1.42-1.70, P < 0.001). In conclusion, rs2254546 polymorphism might significantly contribute to the risk of KD.

Orbital cellulitis presenting as a first sign of incomplete kawasaki disease

A 6-year-old boy was referred to our hospital with orbital cellulitis. He had a history of 7 days of fever despite antibiotherapy. At first, he only had pharyngitis and conjunctivitis, but then an orbital mass evolved which restricted the movement of his right eye and there was also periorbital inflammation resembling orbital cellulitis. Examination at presentation revealed conjunctivitis with secretion, periocular inflammation and edema, right-preauricular lymphadenopathy and restriction of upgaze in the right eye. Laboratory findings included a white blood cell count of 19,000 cells per mm3, with 81.5% neutrophils, 15.0% lymphocytes, 1.2% monocytes and 0.4% basophils. The erythrocyte sedimentation rate was 52 mm/h and the C-reactive protein level was 46.3 mg/dl. Magnetic resonance imaging confirmed orbital cellulitis and pansinusitis. Vancomycin (60 mg/kg/day) and meropenem (100 mg/kg/day) were administered, but desquamation on his fingertips and a rash appeared on the tenth day. A pediatric consultation resulted in a diagnosis of incomplete Kawasaki disease (KD). After administration of aspirin, the orbital inflammation regressed in 3 days. No coronary artery lesions were detected on the first echocardiography, but these did appear 6 weeks later. This confirmed the KD diagnosis.