Adjunctive therapies in Kawasaki disease

The Central Role of Interleukin-1 Signalling in the Pathogenesis of Kawasaki Disease Vasculitis: Path to Translation

Kawasaki disease (KD) manifests as an acute febrile condition and systemic vasculitis, the etiology of which remains elusive. Primarily affecting children under 5 years of age, if untreated KD can lead to a significant risk of coronary artery aneurysms and subsequent long-term cardiovascular sequelae, including myocardial ischemia and myocardial infarction. Intravenous immunoglobulin therapy mitigates the risk of aneurysm formation, but a subset of patients exhibit resistance to this treatment, increasing the susceptibility of coronary artery lesions. Furthermore, the absence of a KD-specific diagnostic test or biomarkers complicates early detection and appropriate treatment. Experimental murine models of KD vasculitis have substantially improved our understanding of the disease pathophysiology, revealing the key roles of the NLRP3 inflammasome and interleukin-1 (IL-1) signalling pathway. This review aims to delineate the pathophysiologic findings of KD while summarising the findings for the emerging key role of IL-1β in its pathogenesis, derived from both human data and experimental murine models, and the translational potential of these findings for anti-IL-1 therapies for children with KD.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

Concomitant Kawasaki Disease and Rotavirus Infection-More Than Just a Coincidence: A Case Report

The definitive role of viral infections, such as rotavirus, in causing Kawasaki disease (KD) remains uncertain. However, the intriguing observation of concomitant rotavirus infection and KD suggests a potential association. This study aimed to investigate this relationship. We reported a case of concomitant KD and rotavirus infection complicated by hyponatraemia and anasarca. For the systematic review, we used three large databases, namely PubMed, Ovid, and Scopus, to search articles with the terms "Kawasaki" and "rotavirus". We also used Google Scholar as our secondary source. We included articles that fulfilled the following criteria: (i) articles reporting on children aged 18 and below; (ii) articles reporting on patients infected with rotavirus prior to or concomitant with KD; and (iii) articles written in English only. Three articles were included and analysed in combination with our reported patient. All patients exhibited gastrointestinal symptoms, including diarrhoea and vomiting, in addition to non-resolving fevers, which eventually manifested more signs and symptoms to support the diagnosis of KD. Stool samples from all patients revealed positive rotavirus antigens. Two patients (n = 2) were noted to have hyponatraemia and hypoalbuminaemia. Three (n = 3) manifested coronary artery abnormalities (CAA). Even though the relationship is not fully understood yet, it is known that the combination of these two pathologies can cause catastrophic immune responses and complications.

An Update on Reports of Atypical Presentations of Kawasaki Disease and the Recognition of IVIG Non-Responder Children

Kawasaki disease (KD) is an acute vasculitis with an intrinsic risk of severe involvement of coronary arteries. The worldwide spread of KD and the importance of early diagnosis for preventing cardiovascular complications have ascertained the need for updating guidelines for prompt disease recognition and treatment efficacy assessment. All KD patients who comply with the definition of classic or atypical disease should be treated with intravenous immunoglobulin (IVIG) soon after diagnosis. The objective of our narrative review was to analyze the medical literature about case reports with atypical KD in relation to diagnosis and potential identification of predictors of non-responsiveness to IVIG. Our analysis has shown that the seminal challenge in KD management is the timeliness of diagnosis, although both extreme variability and transience of clinical manifestations make this goal difficult. A non-negligible percentage of patients, especially in the first 6 months of life, might have atypical manifestations of KD, whose painstaking differential diagnosis may be tricky. Many attempts to develop universal scoring systems and detect children at higher risk of IVIG resistance have been rather unsuccessful. Additionally, KD may show different evolutions according to unraveled demographic, genetic, or epigenetic factors. Further research is needed to elucidate all open questions about KD and clarify the long-term outcome of its potential complications.

Interleukin-33/ST2 Axis as Potential Biomarker and Therapeutic Target in Kawasaki Disease

Kawasaki disease (KD) is an acute, self-limiting, febrile systemic vasculitis of unknown cause associated with the development of coronary artery lesions (CALs) during childhood. Damage-associated molecular patterns (DAMPs) from cell death and oxidative stress have been shown to be involved in the development of KD vasculitis. Interleukin (IL)-33 is released from damaged endothelial cells and acts as a DAMP. We studied whether IL-33 and its receptor (ST2) might be involved in KD pathogenesis. Serum levels of soluble ST2 (sST2) in KD patients were measured before their first therapy. Furthermore, we investigated the impact of IL-33 on human coronary artery endothelial cells (HCAECs). Serum levels of sST2 were significantly higher in KD patients with CALs than in those with normal coronary arteries. In vitro, IL-33 upregulated the expression of ST2L and increased production of sST2, IL-6, IL-8, and monocyte chemoattractant protein-1 in HCAECs in a time- and concentration-dependent manner. Moreover, IL-33 induced significantly greater production of IL-6 and IL-8 in HCAECs compared to the condition stimulated with isoconcentration of tumor necrosis factor-α. The results of the present study suggest that the IL-33/ST2 axis might be involved in the development of KD vasculitis. The IL-33/ST2 axis may be a therapeutic target for the treatment of KD.

Differences in Sensitivity Between the Japanese and Z Score Criteria for Detecting Coronary Artery Abnormalities Resulting from Kawasaki Disease

No studies have assessed differences between the Japanese and Z score criteria in the echocardiographic detection sensitivity of coronary artery (CA) abnormalities using large-scale data containing samples from multiple facilities engaged in daily clinical practices of Kawasaki disease (KD). We analyzed data from the 25th Japanese nationwide KD survey, which identified 30,415 patients from 1357 hospitals throughout Japan during 2017-2018. Hospitals were classified according to their use of Z score criteria. We assessed differences in hospital and patient background factors and compared the prevalence of CA abnormalities among groups using the Z score criteria. Multivariable logistic regression analyses were performed to evaluate differences in the detection sensitivity for CA abnormalities. The Z score criteria were more likely to be utilized in larger hospitals with more pediatricians and cardiologists. Even after controlling for potential confounders, detection sensitivities by the Z score criteria were significantly higher than by the Japanese criteria in patients with CA dilatations (adjusted odds ratio (95% confidence interval) 1.77 (1.56-2.01)) and aneurysms (1.62 (1.17-2.24)). No significant difference was found in patients with giant CA aneurysms. Compared with the Japanese criteria, the Z score criteria were significantly more sensitive for detecting patients with CA dilatations regardless of age, and for those with CA aneurysms only in patients aged ≤ 1 year. Our results indicate that differences in the detection sensitivity for CA abnormalities between the Z score and the Japanese criteria were dependent on the CA size and patient age.

Association of Acute Anti-inflammatory Treatment With Medium-term Outcomes for Coronary Artery Aneurysms in Kawasaki Disease

Background

The impact of adjunctive anti-inflammatory treatment on outcomes for patients with Kawasaki disease (KD) and coronary artery aneurysms (CAAs) is unknown.

Methods

Using data from the International KD Registry in patients with ≥ medium CAA we evaluate associations of treatment with outcomes and major adverse cardiac events (MACE).

Results

Medium or large CAA was present in 527 (32%) patients. All were treated with intravenous immunoglobulin (IVIG), 70% were male, and the median age was 1.3 years (interquartile range: 0.4-4.0 years). The most common acute therapies included single IVIG alone in 243 (46%), multiple IVIG in 100 (19%), multiple IVIG + corticosteroids in 75 (14%), and multiple IVIG + infliximab + corticosteroids in 44 (8%) patients. Patients who received therapy beyond single IVIG had a larger CA z-score at baseline (P < 0.001) and a higher rate of bilateral CAA (P < 0.001). Compared with IVIG alone, early adjunctive treatments (within 3 days of initial IVIG) were not associated with time to CAA regression or MACE, whereas later adjunctive therapy was associated with MACE and longer time to CAA regression. Patients receiving IVIG plus steroids vs IVIG alone had a trend towards shorter time to CAA regression and lower risk of MACE (P = 0.07). A larger CAA z-score at baseline was the strongest predictor of an increase in the CAA z-score over follow-up, lower likelihood of CAA regression, and higher risk of MACE.

Conclusions

Persistence of CAA and MACE are more strongly associated with baseline severity CAA than with acute adjuvant anti-inflammatory therapy. Patients who received late adjunctive therapy are at higher risk for worse outcomes.

Serum alanine aminotransferase level and intravenous immunoglobulin resistance in patients with kawasaki disease

INTRODUCTION/OBJECTIVES

Serum alanine aminotransferase (ALT) elevation is considered a risk factor for resistance to initial intravenous immunoglobulin (IVIG) treatment in patients with Kawasaki disease (KD). However, serum ALT levels change dramatically during acute KD illness. We tested the hypothesis that risk assessment for initial IVIG resistance based on serum ALT elevation may differ by examination day after KD onset.

METHODS

We analyzed 18,492 population-based patients who developed KD throughout Japan. First, we epidemiologically evaluated the serum ALT variation at 1‒10 days after disease onset. Second, we conducted multivariable logistic regression to determine the association between serum ALT level and initial IVIG resistance according to timing of initial hospital visit by stratifying the patients into an early group (1‒5 days after onset) and a late group (6‒10 days after onset).

RESULTS

Serum ALT rapidly increased after KD onset, peaked at day 4 of illness, and then declined regardless of IVIG responsiveness. The adjusted odds ratio (OR) increased with increasing serum ALT in the early group (adjusted OR [95% CI]: 1.44 [1.25-1.66], 1.94 [1.65-2.28], and 2.22 [1.99-2.48] for serum ALT 50-99, 100-199, and ≥ 200 IU/L, respectively; reference ALT level: 1-49 IU/L). No significant association was observed in the late group.

CONCLUSIONS

The findings indicate that risk assessment for initial IVIG resistance based on serum ALT level may only be reliable for patients with KD who visit hospitals during early illness, specifically 1-5 days after disease onset. Key Points Serum alanine aminotransferase level differed markedly according to examination days after Kawasaki disease onset. Serum alanine aminotransferase level declined toward normal range after day 5 of illness regardless of intravenous immunoglobulin responsiveness. Elevated serum alanine aminotransferase level was no longer a significant risk factor for initial intravenous immunoglobulin resistance when measured on delayed hospital visits. Risk assessment for initial intravenous immunoglobulin resistance based on serum alanine aminotransferase level may only be reliable for patients who visit hospitals during early illness, specifically 1-5 days after disease onset.

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.

Targeting TNF-α for COVID-19: Recent Advanced and Controversies

Recent advances in the pathophysiologic understanding of coronavirus disease 2019 (COVID-19) suggests that cytokine release syndrome (CRS) has an association with the severity of disease, which is characterized by increased tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-2, IL-7, and IL-10. Hence, managing CRS has been recommended for rescuing severe COVID-19 patients. TNF-α, one of the pro-inflammatory cytokines commonly upregulated in acute lung injury, triggers CRS and facilitates SARS-CoV-2 interaction with angiotensin-converting enzyme 2 (ACE2). TNF-α inhibitors, therefore, may serve as an effective therapeutic strategy for attenuating disease progression in severe SARS-CoV-2 infection. Below, we review the possibilities and challenges of targeting the TNF-α pathway in COVID-19 treatment.

First-line corticosteroids for Kawasaki disease: Pulse versus multiple dose

BACKGROUND

Kawasaki disease (KD) can result in severe coronary artery abnormalities (CAAs). Corticosteroids added to initial standard intravenous immunoglobulin (IVIG) treatment may decrease the risk for these complications. Different corticosteroid regimens (single-day high dose pulse vs multiple lower doses) may contribute to the discrepant results of prior studies.

METHODS

Using data from the 22nd, 23^rd , and 24th Japanese nationwide KD surveys (2011-2016), we identified KD patients who did not have CAAs at first presentation and who were treated with either pulse or multiple-dose corticosteroids as part of their initial treatment. Occurrence of subsequent CAAs and treatment failure were compared between the treatment regimens and adjusted odds ratios were calculated controlling for sex, age group, illness day at first treatment, survey, and recurrent KD.

RESULTS

There were 782 KD patients who received pulse corticosteroid treatment and 4,817 who received multiple dose treatment. Patients receiving multiple dose treatment were less likely to develop CAAs (5.5% vs 8.3%, OR 0.64; 95% CI: 0.48-0.85) or treatment failure (21.4% vs 41.6%; OR: 0.38; 95% CI: 0.33-0.45). Adjusted analyses showed similar protective effects of multiple-dose treatment against CAAs (OR: 0.67, 95% CI: 0.51-0.90) and treatment failure (OR: 0.39, 95% CI: 0.33-0.46).

CONCLUSIONS

Multiple-dose corticosteroid combination treatment resulted in substantially improved outcomes in KD patients compared to pulse treatment. For patients who may be at elevated risk of treatment failure or CAA, use of multiple-dose corticosteroids in conjunction with IVIG is likely to provide considerable clinical benefit.

Serum sodium level associated with coronary artery lesions in patients with Kawasaki disease

INTRODUCTION/OBJECTIVES

Hyponatremia is a potential risk factor for the development of coronary artery lesions (CALs) identified after acute Kawasaki disease (KD). However, the serum sodium distribution corresponding to the reference intervals differs between infants (< 1 year of age) and older children. We hypothesized the association of serum sodium level with CAL complications differs between infants and older patients with KD.

METHODS

We analyzed 21,610 population-based patients who developed KD throughout Japan during 2013-2014. We performed multivariable logistic regression analyses to evaluate the association between serum sodium and CAL complications. Additionally, we stratified the serum sodium distribution associated with CAL complications by infants and older patients.

RESULTS

CALs were identified in 158 (3.6%) infants and 302 (1.8%) older patients. Infants were more likely to develop CALs when within the normal sodium range compared with older patients (75% vs. 29%), whereas most older patients developed CALs with a sodium level lower than the reference interval. Serum sodium ≤ 130 mEq/L indicated significantly higher risk for development of CALs in both groups (adjusted odds ratio [95% confidence intervals] = 3.21 [1.65-6.25] in infants and 1.74 [1.18-2.57] in older patients).

CONCLUSIONS

Serum sodium distribution associated with CAL complications differed greatly between infants and older patients. Older patients developed CALs with sodium levels lower than the reference interval; however, among infants, hyponatremia was not necessarily a risk factor for developing coronary artery lesion. When considering risk assessments for CALs using serum sodium levels, infants with KD should be distinguished from older patients. Key Points • Hyponatremia is a potential risk factor for the development of coronary artery lesions (CALs) among patients with Kawasaki disease. • However, the serum sodium distribution corresponding to the reference intervals differs between infants (< 1 year of age) and older children. • Most infants developed CALs within the normal sodium range, whereas older patients developed at a range lower than the reference interval. • These findings highlight that when considering risk assessments for CALs using serum sodium levels, infants should be distinguished from older patients.

Use of Infliximab in the Treatment of Macrophage Activation Syndrome Complicating Kawasaki Disease

Kawasaki disease (KD) is an acute systemic vasculitis of unknown etiology. KD can be complicated with macrophage activation syndrome. The optimal treatment for this KD complication has not been established, and a variety of treatments have been used. Infliximab, a chimeric monoclonal antibody that binds tumor necrosis factor, has proved to be efficacious in IV gammaglobulin resistant KD. We present 2 cases of KD complicated with macrophage activation syndrome, including 1 patient with DiGeorge syndrome successfully treated with a combined treatment of IV gammaglobulin, corticosteroids, cyclosporine, and infliximab.

Kawasaki Disease With Coronary Artery Lesions Detected at Initial Echocardiography

Background

Detection of coronary artery lesions (CALs) at initial echocardiography can aid in diagnosing Kawasaki disease (KD) and inform primary adjunctive treatments. We aimed to characterize patients with KD with CALs detected at initial echocardiography.

Methods and Results

We analyzed data from the nationwide Japanese KD survey that contained information on 103 222 population‐based patients diagnosed with KD across Japan during 2011 to 2018. Patients with CALs detected at initial echocardiography were assessed by age, day of illness, and number of principal KD signs (≥3). Multivariable logistic regression analysis was performed to evaluate factors independently associated with CAL detection. Overall, 3707 (3.6%) patients had CALs detected at initial echocardiography. Patients aged <12 and ≥60 months were associated with CAL detection (adjusted odds ratio [95% CI], 1.28 [1.18‒1.39] and 1.32 [1.20‒1.45], respectively; reference, 12‒59 months). Patients with delayed hospital visits were increasingly at higher risk for CAL detection (days 7‒8, 1.84 [1.63‒2.08]; days 9–10, 4.30 [3.58–5.15]; and days ≥11, 9.12 [7.63‒10.90]; reference, days 1–4). Patients with 3 or 4 principal KD signs were independently associated with CAL detection (1.75 [1.63‒1.88]). These patients were significantly more likely to be aged <12 months but were not associated with delayed hospital visit. Younger patients visited at earlier days of illness.

Conclusions

Timely diagnosis could be beneficial for patients with KD. However, even when the hospital visit occurred early in the course of illness, patients with 3 or 4 principal KD signs, especially younger patients, were at higher risk of CAL detection at initial echocardiography.

Cyclophosphamide use in treatment of refractory Kawasaki disease with coronary artery aneurysms

BACKGROUND

Despite timely administration of IVIG, some patients with Kawasaki disease (KD) develop rapidly progressive or giant coronary artery aneurysms (CAA).

CASE PRESENTATION

We describe our experience using cyclophosphamide (CYC) for the treatment of such cases as well as a review of the literature on the use of CYC in KD. Through a retrospective chart review of our KD population, we identified ten children treated for KD with intravenous CYC (10 mg/kg/dose) for one or two doses. Seven patients were male, the median age was 2.0 years (range 4 months - 5 years). All patients received initial IVIG between day 4-10 of illness. Other anti-inflammatory treatments administered before CYC included second IVIG (n = 9), corticosteroids (n = 10), infliximab (n = 4), cyclosporine (n = 2), and anakinra (n = 1). Median illness day at administration of the first CYC dose was 22.5 days (range:10-36 days). The primary indication for treatment with CYC for all patients was large or giant CAA and/or rapid progression of CAA. Three patients received a second dose of CYC (10 mg/kg) for progressively enlarging CAA. CAA did not progress after final CYC treatment. One patient with a history of neutropenia in infancy developed severe neutropenia 9 days after treatment with CYC, which recovered without intervention or complications. No patient developed infections or other serious toxicity from CYC.

CONCLUSION

In KD patients with severe and progressive enlargement of CAA despite anti-inflammatory therapy, CYC seemed to arrest further dilation and was well-tolerated. Future multicenter studies are needed to confirm our findings in this subgroup of KD patients.

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

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

Profile of Kawasaki disease at a tertiary care center in India

Background

Kawasaki disease (KD) is the most common cause of acquired heart disease in developed countries. KD is increasingly being reported from India; however, studies involving the large number of patients are few.

Methods

All children presenting to the center from January 2017 to December 2019, diagnosed to have KD, were retrospectively included in the study. Clinical and laboratory profiles, including echocardiograms, were reviewed. Factors contributing to intravenous immunoglobulin (IVIg) refractoriness and the development of coronary artery abnormalities (CAA) were assessed.

Results

A total of 39 children with KD presented to the center during the study. While 32 received initial treatment at our center, seven were referred after the initial IVIg infusion. The age range was 2 months to 11 years (mean 42.15 ± 38.51 months). More than two-thirds of the cohort was male (n = 27/39). Mucosal involvement was the commonest clinical abnormality for the group, followed by rash. Hemoglobin was significantly lower in the group with coronary artery involvement (P = 0.001). CAA (61.5%), incomplete KD, and atypical features were much more common in infants compared to the rest. Refractoriness to treatment was significantly more common in infants (P = 0.029).

Conclusions

A significant proportion of infants with KD had cardiac involvement. Infants were more likely to have IVIg-resistant disease.

Perspective of Immunopathogenesis and Immunotherapies for Kawasaki Disease

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

A Cost Comparison of Infliximab Versus Intravenous Immunoglobulin for Refractory Kawasaki Disease Treatment

BACKGROUND AND OBJECTIVES

In 10% to 20% of cases, Kawasaki disease is refractory to intravenous immunoglobulin (IVIg), an expensive medication under a national shortage. Data suggest that infliximab is a viable alternative to a second dose of IVIg, with similar efficacy and safety. We compared the cost of a second IVIg dose to that of infliximab in the treatment of refractory Kawasaki disease (rKD).

METHODS

A decision analysis model was used to compare rKD treatments: a second dose of IVIg at 2 g/kg versus infliximab at 10 mg/kg. Infliximab monitoring times were 24, 36, and 48 hours. Direct hospital costs beginning at rKD diagnosis were estimated by using 2016-2017 Truven MarketScan data. Redbook was used for drug costs. Calculations were applied to 3 hypothetical cohorts of 100 patients aged 2 (12.5 kg), 4 (16 kg), and 8 years (25.5 kg). Indirect costs included parental missed workdays.

RESULTS

The total direct cost for children receiving IVIg was $1 677 801, $1 791 652, and $2 100 675 for the 2-, 4-, and 8-year-old cohorts. The direct cost of infliximab with 24 hours of monitoring was $853 042, $899 096, and $1 024 101, respectively. A 20% bidirectional sensitivity analysis revealed stability of our model, with overall cost savings with use of infliximab. With monitoring 48 hours after infliximab treatment, 20% changes in length of stay (LOS) tipped the balance for the 2- and 4-year-old cohorts. Overall, IVIg and infliximab LOS had the most influence on our model.

CONCLUSIONS

Infliximab has potential to yield shorter LOS and significant cost savings in the treatment of rKD. Infliximab treatment, followed by 24 hours of monitoring, nearly halved hospital costs, regardless of age.

Kawasaki disease: pathophysiology and insights from mouse models

Kawasaki disease is an acute febrile illness and systemic vasculitis of unknown aetiology that predominantly afflicts young children, causes coronary artery aneurysms and can result in long-term cardiovascular sequelae. Kawasaki disease is the leading cause of acquired heart disease among children in the USA. Coronary artery aneurysms develop in some untreated children with Kawasaki disease, leading to ischaemic heart disease and myocardial infarction. Although intravenous immunoglobulin (IVIG) treatment reduces the risk of development of coronary artery aneurysms, some children have IVIG-resistant Kawasaki disease and are at increased risk of developing coronary artery damage. In addition, the lack of specific diagnostic tests and biomarkers for Kawasaki disease make early diagnosis and treatment challenging. The use of experimental mouse models of Kawasaki disease vasculitis has considerably improved our understanding of the pathology of the disease and helped characterize the cellular and molecular immune mechanisms contributing to cardiovascular complications, in turn leading to the development of innovative therapeutic approaches. Here, we outline the pathophysiology of Kawasaki disease and summarize and discuss the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

This Review outlines the pathophysiology of Kawasaki disease and discusses the progress gained from experimental mouse models and their potential therapeutic translation to human disease.

Kawasaki disease is a childhood systemic vasculitis leading to the development of coronary artery aneurysms; it is the leading cause of acquired heart disease in children in developed countries.

The cause of Kawasaki disease is unknown, although it is suspected to be triggered by an unidentified infectious pathogen in genetically predisposed children.

Kawasaki disease might not be a normal immune response to an unusual environmental stimulus, but rather a genetically determined unusual and uncontrolled immune response to a common stimulus.

Although the aetiological agent in humans is unknown, mouse models of Kawasaki disease vasculitis demonstrate similar pathological features and have substantially accelerated discoveries in the field.

Genetic and transcriptomic analysis of blood samples from patients with Kawasaki disease and experimental evidence generated using mouse models have demonstrated the critical role of IL-1β in the pathogenesis of this disease and the therapeutic potential of targeting this pathway (currently under investigation in clinical trials).

Shock and unresponsiveness to repeated courses of intravenous immunoglobulin in Kawasaki disease: a nationwide database study

BACKGROUND

We aimed to investigate the clinical implications of unresponsiveness to single or repeated courses intravenous immunoglobulin (IVIG) and Kawasaki disease (KD) shock syndrome in patients with KD in an era of a single brand of IVIG.

METHODS

Data were collected from National Health Insurance database 2010-2013. Characteristics of the KD patients were analyzed, including age, gender, shock, and associated coronary aneurysms.

RESULTS

There were 3043 KD patients (male: 1872) identified. Among them, 46 (1.51%) had KDSS, 261 patients (8.5%) had IVIG unresponsiveness, and 225 patients (7.4%) developed coronary aneurysms. Moreover, 51 patients did not respond to the second course IVIG therapy, i.e., re-IVIG unresponsiveness. KDSS was associated with the occurrence of IVIG unresponsiveness (P < 10^-4) and re-IVIG unresponsiveness (P = 0.02). In addition to male gender and KD shock syndrome, IVIG unresponsiveness (OR: 2.18, 95% CI: 1.48-3.22, P = 0.001) and re-IVIG unresponsiveness (OR: 2.87, 95% CI: 1.40-5.89, P = 0.004) were both independent risk factors for coronary aneurysms.

CONCLUSIONS

In a nationwide KD cohort, both IVIG unresponsiveness and re-IVIG unresponsiveness increase the risk of coronary aneurysms. Such observation addresses the importance of refining the treatment for IVIG unresponsiveness, at least in those with KD shock syndrome.

Platelet Count Variation and Risk for Coronary Artery Abnormalities in Kawasaki Disease

BACKGROUND

Platelet count is considered as a biomarker for the development of coronary artery abnormalities (CAAs) among Kawasaki disease (KD) patients. However, previous studies have reported inconsistent results. We addressed the controversial association of platelet count with CAAs using a large-scale dataset.

METHODS

A retrospective cohort study was conducted using KD survey data from Japan (2015-2016; n = 25,448). Classifying patients by intravenous immunoglobulin (IVIG) responsiveness, we described the trends in platelet count using the lowest and highest values along with the specific illness days. Multivariate logistic regression analysis was performed to evaluate the association between platelet count and CAAs, adjusting for relevant factors.

RESULTS

Platelet counts rapidly decreased from admission, reached the lowest count at 6-7 days, and peaked after 10 days. Platelet counts in IVIG non-responders decreased with a lower minimum value than IVIG responders, but subsequently rebounded toward a higher maximum. Compared with patients with normal platelet counts (150-450 × 10/L), patients with abnormally high platelet counts (>450 × 10/L) were more likely to have CAAs at admission (adjusted odds ratio: IVIG responders, 1.50 [95% confidence interval 1.20-1.87] and non-responders, 1.46 [1.01-2.12]). By contrast, IVIG non-responding patients whose counts were below normal (<150 × 10/L) after hospitalization were at higher risk for developing CAAs (2.27 [1.44-3.58]).

CONCLUSIONS

Platelet count varied widely by illness day and was confounded by IVIG responsiveness, which might have contributed to previous inconsistent findings. KD patients with abnormally high platelet counts at admission or abnormally low counts after hospitalization were at higher risk for CAAs.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Elevated Levels of Pentraxin 3 Correlate With Neutrophilia and Coronary Artery Dilation During Acute Kawasaki Disease

Kawasaki disease (KD) is the leading cause of acquired pediatric heart disease in the developed world as 25-30% of untreated patients and at least 5% of treated patients will develop irreversible coronary artery lesions (CAL). Pentraxin-3 (PTX-3) has been well-studied in inflammatory diseases, particularly in cardiovascular diseases associated with vascular endothelial dysfunction. We hypothesized that PTX-3 plays an important role in the development of KD-associated CAL and investigated the circulating levels of PTX-3 in the serum of KD patients. Children with acute KD were followed from diagnosis through normalization of the clinical parameters of inflammation (convalescent phase). Serum samples were obtained and echocardiograms were conducted at several phases of the illness: acute [prior to intravenous immunoglobulin (IVIG) treatment], sub-acute (5-10 days after IVIG treatment), and convalescent (1-4 months after KD diagnosis). Seventy children were included in the final cohort of the study, of whom 26 (37%) presented with CAL and 18 (26%) developed IVIG resistance. The patients included in this study came from diverse ethnic backgrounds, mostly with mixed ancestry/ ethnicity. Significantly increased PTX-3 levels were observed during the acute phase of KD compared to the sub-acute and the convalescent phases. The PTX-3 levels during acute KD were significantly higher among KD patients with CAL compared to patients with normal coronary arteries (NCA). Also, the PTX-3 levels were significantly higher in patients with IVIG resistance. Furthermore, the PTX-3 levels were significantly higher in IVIG-resistant KD patients with CAL as compared to the NCA group. Moreover, the PTX-3 levels were significantly correlated to coronary artery z-score during acute KD and to neutrophil counts throughout KD progression regardless of coronary artery z-score. Elevated PTX-3 levels correlated to elevated neutrophil counts, a known source of PTX-3 in acute inflammation and an important player in the development of KD vasculitis. We, therefore, suggest PTX-3 as a novel factor in the development of KD-associated CAL and propose neutrophil-derived PTX-3 as contributing to KD vascular dysfunction.

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.

Identifying Patients With Kawasaki Disease Safe for Early Discharge: Development of a Risk Prediction Model at a US Children's Hospital

OBJECTIVES

To develop a model to predict risk of intravenous immunoglobulin (IVIg) nonresponse in patients with Kawasaki disease (KD) to assist in early discharge decision-making.

METHODS

Retrospective cohort study of 430 patients 0 to 18 years old discharged from a US children's hospital January 1, 2010, through July 31, 2017 with a diagnosis of KD. IVIg nonresponse was defined as at least 1 of the following: temperature ≥38.0°C between 36 hours and 7 days after initial IVIg dose, receipt of a second IVIg dose after a temperature ≥38.0°C at least 20 hours after initial IVIg dose, or readmission within 7 days with administration of a second IVIg dose. Backward stepwise logistic regression was used to select a predictive model.

RESULTS

IVIg nonresponse occurred in 19% (81 of 430) of patients. We identified a multivariate model (which included white blood cell count, hemoglobin level, platelet count, aspartate aminotransferase level, sodium level, albumin level, temperature within 6 hours of first IVIg dose, and incomplete KD) with good predictive ability (optimism-adjusted concordance index: 0.700) for IVIg nonresponse. Stratifying into 2 groups by a predictive probability cutoff of 0.10, we identified 26% of patients at low risk for IVIg nonresponse, with a sensitivity and specificity of 90% and 30%, respectively, and a negative predictive value of 93%.

CONCLUSIONS

We developed a model with good predictive value for identifying risk of IVIg nonresponse in patients with KD at a US children's hospital. Patients at lower risk may be considered for early discharge by using shared decision-making. Our model may be used to inform implementation of electronic health record tools and future risk prediction research.

Pitfalls in the diagnosis and management of Kawasaki disease: An update for the pediatric dermatologist

Kawasaki disease is easily diagnosed when it presents in its complete form, but because not all characteristic symptoms are always present at the same time, and the diagnosis of incomplete and atypical Kawasaki disease is often challenging, a delay in diagnosis or misdiagnosis often occurs. We present the diagnostic approach to Kawasaki disease with common pitfalls and explain how to avoid them. We also describe current practice and new trends in treatment.

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.