Convergence and divergence in Kawasaki disease and multisystem inflammatory syndrome in children: results from the COVASAKI survey.

OBJECTIVES: To compare Kawasaki disease (KD) and multisystem inflammatory syndrome (MIS-C) in children. METHODS: Prospective collection of demographics, clinical and treatment data. Assessment of type 1 interferon (IFN) score, CXCL9, CXCL10, Interleukin (IL)18, IFNγ, IL6, IL1b at disease onset and at recovery. RESULTS: 87 patients (43 KD, 44 MIS-C) were included. Age was higher in MIS-C compared to KD group (mean 31±23 vs. 94±50 months, p<0.001). Extremities abnormalities (p=0.027), mucosal involvement (p<0.001), irritability (p<0.001), gallbladder hydrops (p=0.01) and lymphadenopathy (p=0.07) were more often recorded in KD. Neurological findings (p=0.002), gastrointestinal symptoms (p=0.013), respiratory involvement (p=0.019) and splenomegaly (p=0.026) were more frequently observed in MIS-C. Cardiac manifestations were higher in MIS-C (p<0.001), although coronary aneurisms were more frequent in KD (p=0.012). In the MIS-C group, the multiple linear regression analysis revealed that a higher IFN score at onset was related to myocardial disfunction (p<0.001), lymphadenopathy (p=<0.001) and need of ventilation (p=0.024). Both CXCL9 and CXCL10 were related to myocardial disfunction (p<0.001 and p=0.029). IL18 was positively associated to PICU admission (0.030) and ventilation (p=004) and negatively associated to lymphadenopathy (0.004). IFNγ values were related to neurological involvement and lymphadenopathy (p<0.001), IL1b to hearth involvement (0.006). A negative correlation has been observed between IL6 values, heart involvement (p=0.013) and PICU admission (p<0.001). CONCLUSIONS: The demographic and clinical differences between KD e MIS-C cohorts confirm previous reported data. The assessment of biomarkers levels at MIS-C onset could be useful to predict a more severe disease course and the development of cardiac complications.

Potential roles of NLRP3 inflammasome in the pathogenesis of Kawasaki disease.

There is a heterogeneous group of rare illnesses that fall into the vasculitis category and are characterized mostly by blood vessel inflammation. Ischemia and disrupted blood flow will cause harm to the organs whose blood arteries become inflamed. Kawasaki disease (KD) is the most prevalent kind of vasculitis in children aged 5 years or younger. Because KD's cardiovascular problems might persist into adulthood, it is no longer thought of as a self-limiting disease. KD is a systemic vasculitis with unknown initiating factors. Numerous factors, such as genetic predisposition and infectious pathogens, are implicated in the etiology of KD. As endothelial cell damage and inflammation can lead to coronary endothelial dysfunction in KD, some studies hypothesized the crucial role of pyroptosis in the pathogenesis of KD. Additionally, pyroptosis-related proteins like caspase-1, apoptosis-associated speck-like protein containing a CARD (ASC), proinflammatory cytokines like IL-1 and IL-18, lactic dehydrogenase, and Gasdermin D (GSDMD) have been found to be overexpressed in KD patients when compared to healthy controls. These occurrences may point to an involvement of inflammasomes and pyroptotic cell death in the etiology of KD and suggest potential treatment targets. Based on these shreds of evidence, in this review, we aim to focus on one of the well-defined inflammasomes, NLRP3, and its role in the pathophysiology of KD.

Coronary Artery Changes in Patients with Multisystem Inflammatory Syndrome in Children: Los Angeles Experience.

We compared cardiac findings in patients with multisystem inflammatory syndrome in children and Kawasaki disease in the first 6 months of the 2020 coronavirus disease pandemic to patients with Kawasaki disease during 2016-2019. We saw a high rate of coronary aneurysms in 2020, with a similar rate of coronary involvement but greater volume and incidence of cardiac dysfunction compared with previous years.

Cardiac pathology and outcomes vary between Kawasaki disease and PIMS-TS.

Overlapping clinical features promoted the discussion of whether Kawasaki disease (KD) and PIMS-TS share pathophysiological features and disease outcomes. Medical records from English patients with KD (2015-02/20, N = 27) and PIMS-TS (02/2020-21, N = 34) were accessed to extract information. Children with PIMS-TS were older and more frequently of minority ethnicity background. They patients more commonly exhibited cytopenias and hyperferritinemia, which associated with diffuse cardiac involvement and functional impairment. In some PIMS-TS cases, cardiac pathology developed late, but outcomes were more favorable. In both, KD and PIMS-TS, baseline coronary diameter was a predictor of outcomes. PIMS-TS treatment more frequently included respiratory and cardiovascular support, and corticosteroids with IVIG. Cardiac involvement in PIMS-TS may be the result of a cytokine storm. Though more severe and diffuse when compared to KD, cardiac involvement of PIMS-TS has a more favorable prognosis, which may, after recovery, mitigate the need for long-term follow up.

Ventricular Repolarization Parameters and Coronary Involvement in Kawasaki Disease.

OBJECTIVES: To evaluate electrocardiogram markers to predict coronary involvement in patients with Kawasaki disease by assessing measures of ventricular repolarization parameters on the 12-lead electrocardiogram. STUDY DESIGN: This cross-sectional study included 180 Spanish and Japanese patients ≤14 years of age with Kawasaki disease, with or without coronary involvement, from 2011 to 2016. We manually measured the Tp-Te/QT ratio and QTc interval (with Bazett's formula) in 12-lead electrocardiogram in the acute and recovery period and explored their potential association with coronary involvement. RESULTS: No association was found between Tp-Te/QT ratio obtained manually in V5 and V6 leads and coronary involvement in the acute (V5:0.25 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .80; V6:0.24 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .86) or the recovery (V5: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.19-0.25], P = .68; V6: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.17-0.25], P = .50) period. By contrast, QTc in V5 and V6 was significantly lower in patients with Kawasaki disease and coronary involvement in the acute period (V5: 378 ms [IQR, 364-395 ms] vs 390 ms [IQR, 371-411 ms], P = .04; V6: 377 ms [IQR, 364-392 ms] vs 390 ms [IQR, 371-410 ms], P = .01). A QTc interval of <385 ms in lead V6 was associated with a 2.5-fold increased risk of coronary involvement (OR, 2.5; 95% CI, 1.2-5.3; P = .02). CONCLUSIONS: Manually measured QTc interval may be a marker of coronary disease in the acute period of Kawasaki disease.

Macrophage activation syndrome in children with Kawasaki disease: an experience from a tertiary care hospital in northwest India.

OBJECTIVES: To carry out a review of clinical characteristics, laboratory profiles, management and outcomes of patients with Kawasaki disease (KD) and macrophage activation syndrome (MAS). METHODS: Medical records of patients treated for KD and MAS between January 1994 and December 2019 were reviewed. Patient demographics, clinical signs, laboratory values, coronary artery abnormalities, treatments and outcomes of patients with KD and MAS were recorded. We also performed a review published studies on the subject. RESULTS: Of the 950 cases with KD, 12 (1.3%; 10 boys, 2 girls) were diagnosed with MAS. The median age at diagnosis was 4 years (range 9 months-7.5 years). The median interval between onset of fever and diagnosis of KD was 11 days (range 6-30). Thrombocytopenia was seen in 11 patients. The median pro-brain natriuretic peptide value was 2101 pg/ml (range 164-75 911). Coronary artery abnormalities were seen in 5 (41.7%) patients; 2 had dilatation of the left main coronary artery (LMCA), 1 had dilatation of both the LMCA and right coronary artery (RCA), 1 had dilatation of the RCA and 1 had bright coronary arteries. All patients received IVIG as first-line therapy for KD. MAS was treated with i.v. methylprednisolone pulses followed by tapering doses of oral prednisolone. Additional therapy included i.v. infliximab (n = 4), second-dose IVIG (n = 1) and oral ciclosporin (n = 1). CONCLUSION: MAS is an unusual and underrecognized complication of KD. In our cohort of 950 patients with KD, 1.3% had developed MAS. KD with MAS is associated with an increased propensity towards development of coronary artery abnormalities.

Delineating phenotypes of Kawasaki disease and SARS-CoV-2-related inflammatory multisystem syndrome: a French study and literature review.

OBJECTIVE: To better define the clinical distinctions between the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-related paediatric inflammatory multisystem syndrome (PIMS) and Kawasaki disease (KD). METHODS: We compared three groups of patients: group 1, cases from our national historic KD database (KD-HIS), before the SARS-CoV-2 pandemic; group 2, patients with KD admitted to an intensive care unit (KD-ICU) from both our original cohort and the literature, before the SARS-CoV-2 pandemic; and group 3, patients with PIMS from the literature. RESULTS: KD-HIS included 425 patients [male:female ratio 1.3, mean age 2.8 years (s.d. 2.4)], KD-ICU 176 patients [male:female ratio 1.3, mean age 3.5 years (s.d. 3.1)] and PIMS 404 patients [male:female ratio 1.4, mean age 8.8 years (s.d. 3.7)]. As compared with KD-HIS patients, KD-ICU and PIMS patients had a higher proportion of cardiac failure, digestive and neurological signs. KD-ICU and PIMS patients also had a lower frequency of typical KD-mucocutaneous signs, lower platelet count, higher CRP and lower sodium level. As compared with KD-HIS and KD-ICU patients, PIMS patients were older and more frequently had myocarditis; they also had fewer coronary abnormalities and lower sodium levels. Unresponsiveness to IVIG was more frequent in KD-ICU than KD-HIS and PIMS patients. CONCLUSION: On clinical grounds, KD-HIS, KD-ICU and PIMS might belong to a common spectrum of non-specific pathogen-triggered hyperinflammatory states. The causes of increasing inflammation severity within the three entities and the different effects on the heart remain to be determined.

Current Understanding of Multisystem Inflammatory Syndrome (MIS-C) Following COVID-19 and Its Distinction from Kawasaki Disease.

PURPOSE OF REVIEW: In this article, I have reviewed current reports that explore differences and similarities between multisystem inflammatory syndrome in children (MIS-C) and other known multisystem inflammatory diseases seen in children, particularly Kawasaki disease. RECENT FINDINGS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a human coronavirus causing the COVID-19 disease which emerged in China in December 2019 and spread rapidly to the entire country and quickly to other countries. Currently, there is a pandemic of SARS-CoV-2 infection that results in 20% of patients admitted to hospital with illness, with 3% developing intractable acute respiratory distress syndrome (ARDS) with high mortality. However, pediatric COVID-19 is still reported to be a mild disease, affecting only 8% of children. Pathogenesis in children is comparable to adults. There are suggested impaired activation of IFN-alpha and IFN regulator 3, decreased cell response causing impaired viral defense, yet the clinical course is mild, and almost all children recover from the infection without major complications. Interestingly, there is a subset of patients that develop a late but marked immunogenic response to COVID-19 and develop MIS-C. Clinical features of MIS-C resemble certain pediatric rheumatologic diseases, such as Kawasaki disease (mucocutaneous lymph node syndrome) which affects small-medium vessels. Other features of MIS-C resemble those of macrophage activation syndrome (MAS). However, recent research suggests distinct clinical and laboratory differences between MIS-C, Kawasaki disease, and MAS. Since the start of the SARS-CoV-2 pandemic, MIS-C has become the candidate for the most common cause of acquired heart disease in children.

Kawasaki disease for the paediatric dermatologist: skin manifestations and new insights into the pathophysiology.

Early diagnosis of Kawasaki disease (KD) is critical to allow prompt initiation of treatment and avoid cardiac complications. All children with KD have fever accompanied by clinical signs, with four of the five classic criteria for complete KD being mucocutaneous, thus creating an important role for dermatologists. Moreover, dermatologists must be familiar with other dermatological findings that are not included in the American Heart Association classification criteria but can support the diagnosis, particularly in incomplete forms of the disease. We review the skin manifestations described for KD and perform an overview of pathophysiological advances and new treatments.

Severe COVID-19, multisystem inflammatory syndrome in children, and Kawasaki disease: immunological mechanisms, clinical manifestations and management.

Multisystem inflammatory syndrome (MIS-C) is a pediatric hyperinflammation disorder caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). It has now been reported from several countries the world over. Some of the clinical manifestations of MIS-C mimic Kawasaki disease (KD) shock syndrome. MIS-C develops 4-6 weeks following SARS-CoV-2 infection, and is presumably initiated by adaptive immune response. Though it has multisystem involvement, it is the cardiovascular manifestations that are most prominent. High titres of anti-SARS-CoV-2 antibodies are seen in these patients. As this is a new disease entity, its immunopathogenesis is not fully elucidated. Whether it has some overlap with KD is still unclear. Current treatment guidelines recommend use of intravenous immunoglobulin and high-dose corticosteroids as first-line treatment. Mortality rates of MIS-C are lower compared to adult forms of severe COVID-19 disease.

Kawasaki Disease and Multisystem Inflammatory Syndrome in Children: An Overview and Comparison.

Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) are inflammatory conditions that present diagnostic and therapeutic challenges to the physician. Although many of their features overlap, they are two distinct conditions. KD is a febrile illness most commonly affecting children younger than five years. It manifests with prolonged fever and at least four of the following features: bilateral bulbar conjunctivitis, mucositis, diffuse maculopapular rash, extremity changes, and cervical lymphadenopathy of 1.5 cm or more in diameter. Patients with MIS-C may have many of the same manifestations but tend to have higher rates of gastrointestinal and neurocognitive symptoms and signs of shock on presentation. Both conditions are associated with cardiac sequelae, including coronary artery aneurysms, although children with MIS-C are at high risk of developing ventricular dysfunction and depressed cardiac output. Lymphocytopenia, thrombocytopenia, elevated troponin, and elevated B-type natriuretic peptide are key laboratory findings of MIS-C that can help distinguish it from KD. The use of intravenous immune globulin is well established in KD and also appears to have a role in the treatment of MIS-C. Aspirin has been used in KD for an anti-inflammatory effect, and low-dose aspirin is recommended for MIS-C to reduce the risk of thrombosis. In addition to supportive care, patients with MIS-C may benefit from immunomodulatory medications, although data on this topic are evolving.

Role of a Pediatric Cardiologist in the COVID-19 Pandemic.

Coronavirus disease 2019 (COVID-19) has affected patients across all age groups, with a wide range of illness severity from asymptomatic carriers to severe multi-organ dysfunction and death. Although early reports have shown that younger age groups experience less severe disease than older adults, our understanding of this phenomenon is in continuous evolution. Recently, a severe multisystem inflammatory syndrome in children (MIS-C), with active or recent COVID-19 infection, has been increasingly reported. Children with MIS-C may demonstrate signs and symptoms of Kawasaki disease, but also have some distinct differences. These children have more frequent and severe gastrointestinal symptoms and are more likely to present with a shock-like presentation. Moreover, they often present with cardiovascular involvement including myocardial dysfunction, valvulitis, and coronary artery dilation or aneurysms. Here, we present a review of the literature and summary of our current understanding of cardiovascular involvement in children with COVID-19 or MIS-C and identifying the role of a pediatric cardiologist in caring for these patients.

Effectiveness of lopinavir/ritonavir on COVID-19-related pneumonia in a child with COVID-19-associated Kawasaki disease.

The large outbreak of coronavirus disease 2019 (COVID-19) is spreading all over the world rapidly. There have recently been publications in the literature regarding the relationship between COVID-19 and Kawasaki disease, but there is no sufficient knowledge about the treatment and follow-up.

Cutaneous manifestations of COVID-19.

The severe acute respiratory syndrome coronavirus two (SARS-CoV-2), which causes the 2019 coronavirus disease (COVID-19), has infected patients worldwide. Physicians have increasingly identified cutaneous findings as a significant clinical manifestation of COVID-19. In this review, we describe the clinical presentation, onset, duration, associated symptoms, treatment, and outcome of cutaneous manifestations thus far reported to be related to COVID-19. We have included data from 63 studies and subdivided reported cutaneous manifestations into the categories of viral exanthem, urticarial, vesicular, chilblains/chilblains-like, non-chilblains vasculopathy-related, pityriasis rosea-like, erythema multiforme-like, Kawasaki/Kawasaki-like disease, and others. Physicians should be aware of the known common cutaneous manifestations of COVID-19 and future research is required to better understand the pathophysiology and prognosis of each COVID-19-related skin manifestation.

On the genetics and immunopathogenesis of COVID-19.

Most severe cases with COVID-19, especially those with pulmonary failure, are not a consequence of viral burden and/or failure of the 'adaptive' immune response to subdue the pathogen by utilizing an adequate 'adaptive' immune defense. Rather it is a consequence of immunopathology, resulting from imbalanced innate immune response, which may not be linked to pathogen burden at all. In fact, it might be described as an autoinflammatory disease. The Kawasaki-like disease seen in children with SARS-CoV-2 exposure might be another example of similar mechanism.

IL-1-dependent electrophysiological changes and cardiac neural remodeling in a mouse model of Kawasaki disease vasculitis.

Kawasaki disease (KD) is the leading cause of acquired heart disease in children. In addition to coronary artery abnormalities, aneurysms and myocarditis, acute KD is also associated with echocardiogram (ECG) abnormalities in 40-80% of patients. Here, we show that these ECG changes are recapitulated in the Lactobacillus casei cell wall extract (LCWE)-induced KD vasculitis mouse model. LCWE-injected mice developed elevated heart rate and decreased R wave amplitude, with significant differences in prolonged ventricular repolarization. LCWE-injected mice developed cardiac ganglion inflammation, that may affect the impulse-conducting system in the myocardium. Furthermore, serum nerve growth factor (NGF) was significantly elevated in LCWE-injected mice, similar to children with KD vasculitis, associated with increased neural remodeling of the myocardium. ECG abnormalities were prevented by blocking interleukin (IL)-1 signaling with anakinra, and the increase in serum NGF and cardiac neural remodeling were similarly blocked in Il1r1-/- mice and in wild-type mice treated with anakinra. Thus, similar to clinical KD, the LCWE-induced KD vasculitis mouse model also exhibits electrophysiological abnormalities and cardiac neuronal remodeling, and these changes can be prevented by blocking IL-1 signaling. These data support the acceleration of anti-IL-1 therapy trials to benefit KD patients.

Assessment of Platelet Thrombus Formation under Flow Conditions in Patients with Acute Kawasaki Disease.

OBJECTIVE: To assess platelet thrombus formation (PTF) under flow conditions in patients with Kawasaki disease. Previously available platelet activation data were limited for nonphysiological shear stress condition. The total thrombus-formation analysis system (T-TAS) was developed for quantitative PTF analysis. STUDY DESIGN: In total, 33 patients with acute Kawasaki disease were assessed. Whole blood samples, obtained immediately before treatment and 1 week and 1 month after treatment, were assessed using the T-TAS with a collagen-coated platelet chip under high shear values (1000 s-1 [PL12] and 2000 s-1 [PL24]). Measures, such as time to reach 5 kPa above the base pressure (T5+α) and area under the curve for flow pressure curve for 10 minutes (AUC10) were analyzed to quantify PTF. RESULTS: Immediately before treatment, the median PL12-T5+α and PL24-T5+α were 3.3 minutes (IQR 2.0-4.5) and 1.3 minutes (0.9-1.9), respectively, and both values were significantly lower in adult controls (3.5 minutes [2.9-6.4] and 2.8 minutes [1.8-4.8]; P = .015 and P < .001, respectively). In addition, the PL12-AUC10 (151.7 U [94.5-279.9]) significantly decreased in adult controls (234.1 U [110.5-306.5], P = .007). By contrast, at 1 week and 1 month after the start of treatment, the T5+α was longer, and the PL12-AUC10 and PL24-AUC10 decreased. CONCLUSIONS: In patients with acute Kawasaki disease, the PTF had an early onset and weak stability.

Clinical observation of noncoronary cardiac abnormalities in Chinese children with Kawasaki disease.

BACKGROUND: Kawasaki disease (KD) is an acute, self-limited vasculitis. Coronary artery aneurysm (CAA) serves as a major contributor to the long-term prognosis of KD. In addition, acute KD usually also leads to several kinds of noncoronary cardiac abnormalities (NCA) involving the pericardium, myocardium and endocardium. MATERIALS AND METHODS: A total of 142 Chinese children with KD were recruited from July 2015 to April 2018. Blood samples were collected at 24 hours pre-intravenous immunoglobulin (IVIG) therapy. Several inflammatory mediators and biomarkers for acute myocardial infarction were detected. Echocardiography and electrocardiography (ECG) were performed. RESULTS: Plasma white blood cell counts (WBC) were significantly increased in patients with IVIG-nonresponsive KD when compared with their IVIG-responsive counterparts. A total of 106 children (74.65%) suffered from NCA, including 8 patients (5.63%) with pericardial effusion, 23 patients (16.20%) with acute myocarditis, 101 patients (71.13%) with valvular regurgitation and 8 patients (5.63%) with abnormal ECG. No significant differences were observed in the distribution of clinical classification and the response to IVIG therapy regardless of NCA exhibited or not. CONCLUSIONS: Noncoronary cardiac abnormalities is almost universal in acute KD and mainly manifests as valvular regurgitation. However, it has no influence on clinical classification and the response to IVIG therapy.

A Comprehensive Update on Kawasaki Disease Vasculitis and Myocarditis.

PURPOSE OF THE REVIEW: Kawasaki disease (KD) is a childhood systemic vasculitis of unknown etiology that causes coronary artery aneurysms (CAA), and if left undiagnosed can result in long-term cardiovascular complications and adult cardiac disease. Up to 20% of KD children fail to respond to IVIG, the mainstay of therapy, highlighting the need for novel therapeutic strategies. Here we review the latest findings in the field regarding specific etiology, genetic associations, and advancements in treatment strategies to prevent coronary aneurysms. RECENT FINDINGS: Recent discoveries using the Lactobacillus casei cell wall extract (LCWE)-induced KD vasculitis mouse model have accelerated the study of KD pathophysiology and have advanced treatment strategies including clinical trials for IL-1R antagonist, Anakinra. KD remains an elusive pediatric vasculitis syndrome and is the leading cause of acquired heart disease among children in the USA and developed countries. Advancements in combination treatment for refractory KD with further understanding of novel genetic risk factors serve as a solid foundation for future research endeavors in the field.

Risk factors associated with progression and persistence of small- and medium-sized coronary artery aneurysms in Kawasaki disease: a prospective cohort study.

To identify the risk factors of progression and persistence of small- and medium-sized coronary artery aneurysm (CAA) in a contemporary cohort of patients with Kawasaki disease (KD) and to determine the relationship between CAA progression and persistence. A total of 89 KD patients with small- and medium-sized CAA were prospectively enrolled. All patients were followed up at least for 2 years by serial echocardiography. Multivariate logistic regression analysis was conducted to evaluate independent risk factors for CAA progression and persistence. A total of 46 (51.7%) and 73 (82.0%) patients showed echocardiographic CAA regression by 1 month and 24 months of follow-up, respectively. CAA progression was documented in 12 (13.5%) patients during follow-up. The initial aneurysm size according to CAA classification (OR 0.089, 95% CI 0.013-0.634, P = 0.016) and CAA progression (OR 42.618, 95% CI 3.740-485.6, P = 0.003) were independently associated with CAA persistence. The number of involved coronary arteries (OR 0.223, 95% CI 0.065-0.767, P = 0.015) and lymphocyte proportion (OR 1.327, 95% CI 1.019-1.727, P = 0.040) were independently associated with CAA progression.Conclusion: Patients with KD and greater initial aneurysm size, CAA progression, more involved coronary arteries, and lower lymphocyte proportion may require intensive cardiac monitoring and adjuvant therapies.What is Known:• Long-term outcomes of patients with KD and CAA are primarily driven by the consequences of CAA regression and progression.• Regression and progression occurs more frequently in patients with small- and medium-sized CAAs, and less frequently for giant CAAs.What is New:• The CAA size at diagnosis, NCAI, and the proportion of lymphocytes are presumably associated with the small- and medium-sized CAA persistence or CAA progression.• The CAA progression was associated with CAA persistence.