Secular trend of Kawasaki disease and its correlation with viral activity in Taiwan: a nationwide population-based study.

BACKGROUND: Kawasaki disease (KD) is the most important acquired heart disease in children. This study investigated annual incidence, seasonality, secular trend and the correlation of KD incidence with viral activity in Taiwan. METHODS: Through the national health insurance database, we identified KD during 2001-2020. The viral activity was obtained from nationwide surveillance database. We analyzed KD age-specific annual incidence, secular trends, seasonality and the correlation between KD incidence and common enteric or respiratory viral activity. RESULTS: The KD incidence of subjects younger than 18 years significantly increased from 2001 to 2020 (11.78 and 22.40 per 100,000 person-years, respectively), and substantially decreased with age. Infants younger than 1 year presented the highest KD annual incidence at 105.82 to 164.34 per 100,000 person-years from 2001 to 2020. For all KD patients, the most frequently occurring season was summer followed by autumn. The KD incidence of infants younger than 1 year had significantly positive correlation with enteric (r = 0.14) and respiratory (r = 0.18) viral activity. CONCLUSIONS: This study demonstrates the increasing trend of KD annual incidence and seasonality (more in summer and autumn) in Taiwan. The activity of common respiratory and enteric viruses was significantly correlated with KD incidence in infants.

Six-year trend of subsequent allergic diseases following Kawasaki disease and its clinical implications: A population-based matched cohort study of 34,712 patients.

BACKGROUND: It has been suggested that allergic diseases may increase after Kawasaki disease (KD). We aimed to analyze the temporal patterns of allergic disease incidence after KD. METHODS: A nationwide population-based matched cohort study was conducted using data from the Korean National Health Insurance claims database. Patients aged <5 years diagnosed with KD and their 1:3 propensity score-matched controls were included. Three cohorts were established: Cohort A, patients with allergies; Cohort B, patients without allergies; and Cohort C, patients without allergies, but excluding patients with birth history and underlying medical conditions. Cumulative incidence rates (%) and associated hospital visits for allergic rhinitis, atopic dermatitis, urticaria, and asthma were compared between the cases and controls during the 6-year follow-up period. RESULTS: The study population comprised 8678 patients diagnosed with KD and 26,034 controls. In Cohort A, although initially, there were intergroup differences in the number of hospital visits for certain allergic diseases, these differences were inconsistent and varied depending on the type of allergic disease. Over time, the differences narrowed, and by the sixth year, the gap had decreased significantly. In Cohorts B and C, the initial incidence rates of the four allergic diseases and associated hospital visits were lower in patients with KD as compared to controls. However, with a faster rate of increase, the incidence rates and number of hospital visits eventually surpassed those of the controls. CONCLUSIONS: The pattern of delayed increase in cumulative incidence rates and hospital visits for allergic diseases after KD suggests the possibility of a shared genetic or immunologic susceptibility between KD and allergic diseases, which becomes evident over time, rather than a direct influence of KD resulting in allergic diseases.

Exploring viral infections' role in Kawasaki disease onset: A study during the COVID-19 pandemic.

During the coronavirus disease 2019 (COVID-19) pandemic, known viral diseases declined in all ages. By using the current situation as a natural experiment, this study aimed to evaluate whether the change in the incidence of Kawasaki disease (KD) during the COVID-19 pandemic varies with age and whether a specific infectious disease mediates the occurrence of KD. Monthly number of KD patients were extracted from the nationwide inpatient database. Segmented regression analysis was conducted on the interrupted time series data. Additionally, causal mediation analysis was performed to examine the role of viral infections in the changes in the number of KD patients. After the first emergency declaration for COVID-19 in Japan, there was an immediate decrease in the number of KD patients per 100 000 population aged between 6 months and 4 years (immediate change = -2.66; 95% confidence interval [CI]: -5.16 to -0.16) and aged 5-15 years (immediate change = -0.26; 95% CI: -0.49 to -0.04). However, no immediate change was observed in patients under 6 months of age. In the causal mediation analysis for each viral infection, it was found that the decrease in the number of patients with KD was mediated by changes in the number of patients with pharyngoconjunctival fever and infectious gastroenteritis. The current results suggest that viral infections may be one of the etiological agents for KD, while they may not be the main cause in early infancy. Specifically, we found that adenovirus infection and gastroenteritis was closely related to the onset of KD in some areas of Japan.

Relationship between ocular manifestations, laboratory findings, echocardiographic findings, and intravenous immunoglobulin resistance in Kawasaki disease.

BACKGROUND: This study investigates the incidence of ocular involvement in Kawasaki disease (KD) and evaluates the relationship between ocular manifestations, laboratory findings, echocardiographic findings, and intravenous immunoglobulin (IVIG) resistance. METHODS: We conducted a cross-sectional study with 58 KD patients from June 2021 to March 2023. For all patients, a complete ophthalmologic examination and echocardiography were performed in the acute phase before starting the treatment. We analyzed the age, sex, mean of white blood cell (WBC) count, platelet count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), echocardiographic findings and IVIG responses for all patients and compared the group with ocular involvement with the group without involvement. RESULTS: The incidence of bilateral acute conjunctivitis was 70.7%, while that of acute uveitis was 30%. Patients with uveitis had significantly higher rates of Coronary artery dilatation and IVIG resistance, as well as higher mean levels of WBC, platelet, and CRP compared to those without uveitis. (P < 0.05). Additionally, the age of patients with uveitis involvement was lower than those without involvement. No significant relationships existed between ESR, AST, or ALT values and uveitis (P > 0.05). Furthermore, no significant correlations existed between any examined items and acute bilateral conjunctivitis. CONCLUSION: Uveitis in KD is significantly associated with coronary artery dilatation, IVIG resistance, higher WBC count, platelet count, and CRP level.

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

BACKGROUND: Kawasaki disease (KD) is an autoimmune disease with cardiovascular disease as its main complication, mainly affecting children under 5 years old. KD treatment has made tremendous progress in recent years, but intravenous immunoglobulin (IVIG) resistance remains a major dilemma. Bibliometric analysis had not been used previously to summarize and analyze publications related to IVIG resistance in KD. This study aimed to provide an overview of the knowledge framework and research hotspots in this field through bibliometrics, and provide references for future basic and clinical research. METHODS: Through bibliometric analysis of relevant literature published on the Web of Science Core Collection (WoSCC) database between 1997 and 2023, we investigated the cooccurrence and collaboration relationships among countries, institutions, journals, and authors and summarized key research topics and hotspots. RESULTS: Following screening, a total of 364 publications were downloaded, comprising 328 articles and 36 reviews. The number of articles on IVIG resistance increased year on year and the top three most productive countries were China, Japan, and the United States. Frontiers in Pediatrics had the most published articles, and the Journal of Pediatrics had the most citations. IVIG resistance had been studied by 1889 authors, of whom Kuo Ho Chang had published the most papers. CONCLUSION: Research in the field was focused on risk factors, therapy (atorvastatin, tumor necrosis factor-alpha inhibitors), pathogenesis (gene expression), and similar diseases (multisystem inflammatory syndrome in children, MIS-C). "Treatment," "risk factor," and "prediction" were important keywords, providing a valuable reference for scholars studying this field. We suggest that, in the future, more active international collaborations are carried out to study the pathogenesis of IVIG insensitivity, using high-throughput sequencing technology. We also recommend that machine learning techniques are applied to explore the predictive variables of IVIG resistance.

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.

Kawasaki disease in Kenya and review of the African literature.

BACKGROUND: Kawasaki disease has been described across the globe, although publications from Africa are limited. To our knowledge, there are no publications on Kawasaki disease from Kenya, which triggered this report. METHODS: A retrospective cross-sectional study was undertaken to identify in-patients with a discharge diagnosis of Kawasaki disease, over 2 different 5-year periods, at two pediatric hospitals in Nairobi, Kenya. We reviewed the medical records of all patients and report their clinical findings, diagnostic workup and treatment. In addition, we undertook a detailed review of the literature. RESULTS: Twenty-three patients with Kawasaki disease were identified, of those 12 (52.2%) had incomplete disease. The mean age was 2.3 years (SD+/-2.2) (range 0.3-10.3) with a male to female ratio of 1:1. The mean duration of fever at diagnosis was 8.3 days (SD+/-4.7) (range 2-20). Oral changes were the most common clinical feature and conjunctivitis the least common. Thrombocytosis at diagnosis was seen in 52% (12/23). Twenty-one patients (91.3%) were treated with intravenous immunoglobulin and all except 1 received aspirin. Baseline echocardiograms were performed in 95.7% (22/23) and found to be abnormal in 3 (13.6%). Follow-up data was limited. Our literature review identified 79 publications with documented cases of Kawasaki disease in children from 22 countries across the African continent with a total of 1115 patients including those from this report. Only 153 reported cases, or 13.7%, are from sub-Saharan Africa. CONCLUSIONS: This is the first publication on Kawasaki disease from Kenya and one of the largest reports from sub-Saharan Africa. It is the first to have a complete review of the number of published cases from the African continent. Challenges in the diagnosis and management of Kawasaki disease in many African countries include disease awareness, infectious confounders, access and cost of intravenous immunoglobulin, access to pediatric echocardiography and follow-up. Increasing awareness and health care resources are important for improving outcomes of Kawasaki disease in Africa.

Association between maternal heavy metal exposure and Kawasaki Disease, the Japan Environment and Children's Study (JECS).

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting young children, with an unclear etiology. We investigated the link between maternal heavy metal exposure and KD incidence in children using the Japan Environment and Children's Study, a large-scale nationwide prospective cohort with approximately 100,000 mother-child pairs. Maternal blood samples collected during the second/third trimester were analyzed for heavy metals [mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se), manganese (Mn)], divided into four quartiles based on concentration levels. KD incidence within the first year of life was tracked via questionnaire. Among 85,378 mother-child pairs, 316 children (0.37%) under one year were diagnosed with KD. Compared with the lowest concentration group (Q1), the highest (Q4) showed odds ratios (95% confidence interval) for Hg, 1.29 (0.82-2.03); Cd, 0.99 (0.63-1.58); Pb, 0.84 (0.52-1.34); Se, 1.17 (0.70-1.94); Mn, 0.70 (0.44-1.11), indicating no concentration-dependent increase. Sensitivity analyses with logarithmic transformation and extended outcomes up to age 3 yielded similar results. No significant association was found between maternal heavy metal levels and KD incidence, suggesting that heavy metal exposure does not increase KD risk.

The etiologies of Kawasaki disease.

Kawasaki disease (KD) is a systemic vasculitis that affects young children and can result in coronary artery aneurysms. The etiology is currently unknown, but new clues from the epidemiology of KD in Japan, the country of highest incidence, are beginning to shed light on what may trigger this acute inflammatory condition. Additional clues from the global changes in KD incidence during the COVID-19 pandemic, coupled with a new birth cohort study from Japan, point to the potential role of person-to-person transmission of an infectious agent. However, the rising incidence of KD in Japan, with coherent waves across the entire country, points to an increasing intensity of exposure that cannot be explained by person-to-person spread. This Review discusses new and historical observations that guide us toward a better understanding of KD etiology and explores hypotheses and interpretations that can provide direction for future investigations. Once the etiology of KD is determined, accurate diagnostic tests will become available, and new, less expensive, and more effective targeted therapies will likely be possible. Clearly, solving the mystery of the etiologies of KD remains a priority for pediatric research.

Association of Previous Antibiotics Use and Kawasaki Disease: A Cohort Study of 106,908 Patients.

BACKGROUND: Microbial imbalance in the gut from antibiotic use may be an etiologic factor of Kawasaki disease (KD). We aimed to identify the association between the use of antibiotics and the development of KD, considering various antibiotic profiles. METHODS: A population-based, case-control study was performed using data from the Health Insurance Review and Assessment Service database. Children <5 years of age, who were diagnosed with KD between 2016 and 2019, were identified. Propensity score-matched controls were selected from the general population in a 1:5 ratio. Four separate study cohorts were created according to different periods of antibiotic use: (1) within 28 days and (2) 12 months after birth and (3) within 6 months and (4) 12 months from the index date. Profiles regarding antibiotic use were compared between patients with KD and matched controls. RESULTS: We included 17,818 patients with KD and 89,090 matched controls. Use of antibiotics within 6 months [odds ratio (OR): 1.18; 95% confidence interval (CI): 1.12-1.26] and 12 months (OR: 1.23; 95% CI: 1.14-1.32) from the index date were associated with the development of KD. The association between antibiotic use and KD was most prominent in patients who had received 3 or more types of antibiotics within 12 months from the index date (OR: 1.26; 95% CI: 1.17-1.37). CONCLUSIONS: Antibiotic use within the preceding 6 or 12 months was associated with KD. Alteration in gut microbiota due to antibiotic usage might play a role in the development of KD.

Age-Dependent Variations in Kawasaki Disease Incidence in Japan.

Importance: The etiology of Kawasaki disease (KD) remains elusive, with immunologic and epidemiologic data suggesting different triggers in individuals who are genetically susceptible. KD remains the most common cause of acquired heart disease in pediatric patients, and Japan is the country of highest incidence, with an increasing number of cases. Objective: To investigate whether an analysis of the epidemiologic KD record in Japan stratified by age and prefecture (subregion) may yield new clues regarding mechanisms of exposure to etiologic agents associated with KD. Design, Setting, and Participants: This cross-sectional study was conducted using a dataset of patients with KD with detailed information on location and age at onset created through nationwide surveys of hospitals caring for pediatric patients with KD throughout Japan. Pediatric patients hospitalized in Japan for KD from 1970 to 2020 were included. Data were analyzed from January 2022 to January 2024. Exposure: Pediatric patients with KD. Main Outcomes and Measures: The KD dataset was analyzed by patient age (infants [aged <6 months], toddlers [aged 6 to <24 months], children aged 2 years [aged 24 to <36 months], and children and adolescents aged 3 years or older [aged ≥36 months]), with investigations of seasonal cycles, interannual variations, and correlations across regions. Results: Among 422 528 pediatric patients (243 803 males [57.7%] and 178 732 females [42.3%]; median [IQR] age, 23.69 [11.96-42.65] months), infants, toddlers, and patients aged 3 years or older exhibited different rates of increase in KD incidence, seasonality, and degrees of coherence of seasonality across prefectures. Although the mean (SD) incidence of KD among infants remained relatively stable over the past 30 years compared with older patients (1.00 [0.07] in 1987-1992 to 2.05 [0.11] in 2011-2016), the mean (SD) incidence rate for children and adolescents aged 3 years or older increased 5.2-fold, from 1.00 (0.08) in 1987 to 1992 to 5.17 (0.46) in 2014 to 2019. Patients aged 3 years or older saw a reduction in mean (SD) incidence, from peaks of 5.71 (0.01) in October 2014 through June 2015 and July 2018 through March 2019 to 4.69 (0.11) in 2016 to 2017 (17.8% reduction) not seen in younger children. The seasonal cycle varied by age group; for example, mean (SD) incidence peaked in July and August (5.63 [0.07] cases/100 000 individuals) for infants and in December and January (4.67 [0.13] cases/100 000 individuals) for toddlers. Mean (SD) incidence changed dramatically for toddlers beginning in the early 2010s; for example, the normalized mean (SD) incidence among toddlers for October was 0.74 (0.03) in 1992 to 1995 and 1.10 (0.01) in 2016 to 2019. Across Japan, the seasonal cycle of KD incidence of older children and adolescents exhibited mean (SD) correlation coefficients between prefectures as high as 0.78 (0.14) for prefecture 14 among patients aged 3 years or older, while that of infants was much less (highest mean [SD] correlation coefficient, 0.43 [0.23]). Conclusions and Relevance: This study found distinct temporal signatures and changing spatial consistency of KD incidence across age groups, suggesting different age-related mechanisms of exposure. Some results suggested that social factors may modulate exposure to etiologic agents of KD; however, the increase in KD incidence in older children coupled with the correlation across prefectures of KD incidence suggest that the intensity of an environmental exposure that triggers KD in this age group may have increased over time.

Retrospective evaluation of 130 cases with kawasaki disease follow-up in a tertiary care center in Turkey between 1999 and 2019: a 20-year experience.

OBJECTIVES: Kawasaki disease (KD), which is a medium vessel vasculitis, is common in Asian countries and is the most common cause of childhood-acquired heart diseases in developed countries. However, disease course and epidemiological data are limited in non-Asian developing countries like ours. We aimed to evaluate the clinical features and prognosis of patients with KD in our country and ethnicity, one of the referee centers of our country. METHODS: Patients with KD in our center for the last 20 years in the pre-COVID-19 pandemic era were included in the study. The clinical and laboratory findings, treatments, and follow-up findings were reviewed retrospectively in different age groups. RESULTS: Of the 130 patients, 82 (63%) were male. The median age at diagnosis was 2.97 years (2 months-11.5 years). Thirty-six (27.7%) patients were diagnosed with incomplete KD, and there was no significant laboratory difference between incomplete KD and complete KD patients. Thirty-three (25.3%) patients had coronary artery lesions (CAL), and it persisted in only 3 of 33 patients. One of 15 patients with IVIG resistance had CAL. The independent risk factors were days of illness at initial IVIG administration for CAL (p = 0.013, OR [95%CI] = 1.20 [1.04-1.38]) and low hemoglobin (p = 0.003, OR [95%CI] = 0.51 [0.33-0.79]) and low sodium for IVIG resistance (p = 0.012, OR [95%CI] = 0.81[0.69-0.95]). CONCLUSIONS: The rate of CAL is approximately three times higher in our results than in the Japanese data in recent years. We showed that the time of IVIG administration is the most critical factor for preventing CAL. Wide-ranging studies are needed to decently predict the disease process according to the age and region of patients.

Incidence of coronary artery lesions in children with recurrent Kawasaki disease.

OBJECTIVE: Coronary artery lesions (CALs) are a major complication of Kawasaki disease (KD); however, data on CAL incidence and risk factors in recurrent KD are limited. METHODS: Ninety-seven children with recurrent KD were retrospectively enrolled from 2013 to 2022, and CAL incidence was tracked during admission, discharge, and during follow-up. RESULTS: Initially, 27.8% had CAL at admission and discharge, declining to 7.2% at 12 months post-discharge. Most patients (66 of 97, 68.0%) did not exhibit CAL at any of the time points, 7 cases presented CAL at all time points, indicating a persistent CAL. The remaining 20 cases presented CAL at admission but recovered at discharge or during follow-up. Notably, transient CALs had presented at discharge, or during the follow-up, but finally resolved at 12 months after discharge. Notably, prior IVIG resistance and increased prothrombin time seemed associated with CAL in recurrent KD, suggesting they could help identify patients needing close monitoring. CONCLUSION: The study highlights decreasing CAL incidence over time in recurrent KD but with diverse patterns, emphasizing the importance of monitoring and further investigations to confirm these findings.

Initial intravenous immunoglobulin therapy without aspirin for acute Kawasaki disease: a retrospective cohort study with a Bayesian inference.

OBJECTIVE: To clarify the necessity of acetylsalicylic acid (ASA) administration combined with intravenous immunoglobulin (IVIG) therapy in the treatment of acute Kawasaki disease. DESIGN: Retrospective cohort study. SETTING: Multicentre. PARTICIPANTS: This study included 735 patients with Kawasaki disease aged ≤10 years and hospitalised between 4 and 10 days of illness in eight Japanese hospitals from January 2016 to December 2020. EXPOSURES: High-dose (HD) ASA was administered with initial IVIG to 333 patients in 6 hospitals (HD group). ASA was not administered routinely to 402 patients in the other two hospitals, and low-dose ASA was only administered when patients developed coronary artery lesions or pericardial effusion (non-HD group). PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the presence of coronary artery lesions, defined as a coronary artery diameter >+2.5 SD of body surface area within 1 month of onset. The secondary outcome was responsiveness to the initial IVIG therapy. Adjusted risk ratios for the outcomes were calculated using modified Poisson regression models. Bayesian analysis was conducted to estimate the posterior probability of the treatment effect of HD ASA under several prior distributions. RESULTS: The incidence of coronary artery lesions was not significantly higher in the HD group than in the non-HD group (12/333 (3.6%) vs 15/402 (4.0%)). The proportion of non-responders to initial IVIG was similar between the two groups (HD group: 78/333 (23%); non-HD group: 83/402 (22%)). In the Bayesian analysis, considering a difference of ≤2% to be of no clinical importance, there was only a 9.3% chance of reduced risk of coronary artery lesions in the HD group compared with the non-HD group even with a strongly enthusiastic prior for HD treatment. CONCLUSIONS: Compared with HD ASA treatment, treatment without ASA in the acute phase of Kawasaki disease was not associated with increased complications from Kawasaki disease.

Association of Kawasaki disease with urbanization level and family characteristics in Taiwan: A nested case-control study using national-level data.

Kawasaki disease (KD) is an inflammatory vasculitis disorder of unknown etiology. It is a rare but fatal disease and the leading cause of acquired coronary heart disease in children under the age of 5 years. We examined the association of KD with the demographics of family members, parents' characteristics, and perinatal factors in Taiwanese children. This nested case-control study used data from Taiwan's Health and Welfare Data Science Center and initially included children born in Taiwan between January 1, 2006, and December 31, 2015 (n = 1,939,449); the children were observed for KD development before the age of 5 years (n = 7870). The control group consisted of children without KD who were matched with each KD case by sex and birth date at a ratio of 8:1. The odds ratio (ORs) of the aforementioned associations were estimated using conditional logistic regression. The risk of KD decreased in children with younger parents [<25 years; younger maternal age, OR = 0.72, 95% confidence interval (CI), 0.66-0.79; younger paternal age, OR = 0.68, 95% CI, 0.59-0.78], lower socioeconomic status, more than 2 siblings (OR = 0.80, 95% CI, 0.73-0.89), and siblings with a history of KD (OR = 4.39, 95% CI, 3.29-5.86). Children living in suburban (OR = 0.95, 95% CI, 0.90-1.00) and rural (OR = 0.81, 95%CI, 0.74-0.90) areas exhibited a lower risk of KD than children living in urban areas. In conclusion, a higher incidence rate of KD was observed in children aged <5 years who had an urban lifestyle, had siblings with KD, were born to older mothers, and belonged to high-income and smaller families. Parental allergic or autoimmune diseases were not associated with the risk of KD.

Kawasaki Disease in the Time of COVID-19 and MIS-C: The International Kawasaki Disease Registry.

BACKGROUND: Patients with multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) have overlapping clinical features. We compared demographics, clinical presentation, management, and outcomes of patients according to evidence of previous SARS-CoV-2 infection. METHODS: The International Kawasaki Disease Registry (IKDR) enrolled KD and MIS-C patients from sites in North, Central, and South America, Europe, Asia, and the Middle East. Evidence of previous infection was defined as: Positive (household contact or positive polymerase chain reaction [PCR]/serology), Possible (suggestive clinical features of MIS-C and/or KD with negative PCR or serology but not both), Negative (negative PCR and serology and no known exposure), and Unknown (incomplete testing and no known exposure). RESULTS: Of 2345 enrolled patients SARS-CoV-2 status was Positive for 1541 (66%) patients, Possible for 89 (4%), Negative for 404 (17%) and Unknown for 311 (13%). Clinical outcomes varied significantly among the groups, with more patients in the Positive/Possible groups presenting with shock, having admission to intensive care, receiving inotropic support, and having longer hospital stays. Regarding cardiac abnormalities, patients in the Positive/Possible groups had a higher prevalence of left ventricular dysfunction, and patients in the Negative and Unknown groups had more severe coronary artery abnormalities. CONCLUSIONS: There appears to be a spectrum of clinical features from MIS-C to KD with a great deal of heterogeneity, and one primary differentiating factor is evidence for previous acute SARS-CoV-2 infection/exposure. SARS-CoV-2 Positive/Possible patients had more severe presentations and required more intensive management, with a greater likelihood of ventricular dysfunction but less severe coronary artery adverse outcomes, in keeping with MIS-C.

Multisystem inflammatory syndrome in 1.2 million children: longitudinal cohort study of risk factors.

BACKGROUND: We identified patient characteristics associated with an increased risk of developing MIS-C. METHODS: We conducted a longitudinal cohort study of 1,195,327 patients aged 0-19 years between 2006 and 2021, including the first two waves of the pandemic (February 25-August 22, 2020 and August 23, 2020-March 31, 2021). Exposures included prepandemic morbidity, birth outcomes, and family history of maternal disorders. Outcomes included MIS-C, Kawasaki disease, and other Covid-19 complications during the pandemic. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for the association between patient exposures and these outcomes using log-binomial regression models adjusted for potential confounders. RESULTS: Among 1,195,327 children, 84 developed MIS-C, 107 Kawasaki disease, and 330 other Covid-19 complications during the first year of the pandemic. Prepandemic hospitalizations for metabolic disorders (RR 11.3, 95% CI 5.61-22.6), atopic conditions (RR 3.34, 95% CI 1.60-6.97), and cancer (RR 8.11, 95% CI 1.13-58.3) were strongly associated with the risk of MIS-C, compared with no exposure. These same exposures were also associated with Kawasaki disease and other Covid-19 complications. However, birth characteristics and history of maternal morbidity were not associated with MIS-C development. CONCLUSIONS: Children with pre-existing morbidity have a considerably elevated risk of MIS-C. IMPACT: Morbidities that predispose children to multisystem inflammatory syndrome (MIS-C) are unclear. In this study, prepandemic hospitalizations for metabolic disorders, atopic conditions, and cancer were associated with an elevated risk of MIS-C. Birth characteristics and family history of maternal morbidity were not, however, associated with MIS-C. Pediatric morbidities may play a greater role in MIS-C onset than maternal or perinatal characteristics, and may help clinicians better recognize children at risk for this complication.

Myocardial work is independent risk factor for coronary artery lesions in children with Kawasaki disease.

BACKGROUND: The recognition ability of noninvasive echocardiographic myocardial work for coronary artery lesions (CAL) in children with Kawasaki disease (KD) has not been well characterized. This study aimed to determine whether impaired myocardial work is an independent risk factor for CAL in children with KD. METHODS: Between December 2021 and April 2023, left ventricular (LV) myocardial work of 59 KD children was evaluated by myocardial work echocardiography, and their demographic, clinical and laboratory data were collected simultaneously. Multivariable logistic regression analysis was used to identify the independent risk factors for CAL. RESULTS: Twenty-seven of 59 KD children had CAL according to the diagnostic criteria of echocardiography. There were significantly different heart rates, white blood cell count, LV ejection fraction, global work index (GWI), global work efficiency and global wasted work (GWW) between KD children with and without CAL ( P < 0.05). Multivariate logistic regression analysis identified that GWI [odds ratio (OR) = 0.985; P = 0.001], GWW (OR = 1.039; P = 0.019), erythrocyte sedimentation rate (ESR, OR = 1.051; P = 0.049) and C-reactive protein (CRP) (OR = 1.017; P = 0.044) were independent risk factors for CAL in children with KD. The area under receiver operating characteristic curve (AUC) of 0.847 for GWI was superior to that for GWW (AUC = 0.708), ESR (AUC = 0.645) and CRP (AUC = 0.626) to predict CAL in KD children ( P < 0.05). The optimal cutoff value of GWI was 1089 mmHg, with a sensitivity of 59.26% and a specificity of 96.87%. CONCLUSION: GWI and GWW were independent risk factors for CAL in KD children with high discrimination ability.

Association between long-term PM2.5 exposure and risk of Kawasaki disease in children: A nationwide longitudinal cohort study.

BACKGROUND: Based on previous studies suggesting air pollution as a potential risk factor for Kawasaki Disease (KD), we examined the association of long-term exposure to childhood fine particulate matter (PM2.5) with the risk of KD. METHODS: We used National Health Insurance Service-National Sample Cohort data from 2002 to 2019, which included beneficiaries aged 0 years at enrollment and followed-up until the onset of KD or age 5 years. The onset of KD was defined as the first hospital visit record with a primary diagnostic code of M30.3, based on the 10th revision of the International Classification of Diseases, and with an intravenous immunoglobulin (IVIG) prescription. We assigned PM2.5 concentrations to 226 districts, based on mean annual predictions from a machine learning-based ensemble prediction model. We performed Cox proportional-hazards modeling with time-varying exposures and confounders. RESULTS: We identified 134,634 individuals aged five or less at enrollment and, of these, 1220 individuals who had a KD onset and an IVIG prescription during study period. The average annual concentration of PM2.5 exposed to the entire cohort was 28.2 µg/m³ (Standard Deviation 2.9). For each 5 µg/m³ increase in annual PM2.5 concentration, the hazard ratio of KD was 1.21 (95% CI 1.05-1.39). CONCLUSIONS: In this nationwide, population-based, cohort study, long-term childhood exposure to PM2.5 was associated with an increased incidence of KD in children. The study highlights plausible mechanisms for the association between PM2.5 and KD, but further studies are needed to confirm our findings.

Association between aspirin dose and outcomes in patients with acute Kawasaki disease: a nationwide retrospective cohort study in Japan.

This study aimed to identify the appropriate dose of aspirin to be prescribed to patients with acute Kawasaki disease (KD). Using a Japanese national inpatient database, we identified patients with KD treated with intravenous immunoglobulin between 2010 and 2021.The outcomes included the occurrence of coronary artery abnormalities and intravenous immunoglobulin resistance, length of hospital stay, and medical costs. Restricted cubic spline functions were performed to examine the association between aspirin dose and the outcomes. Data of 82,109 patients were extracted from the database. Non-linear associations were observed between aspirin dose and the outcomes. In comparison with an aspirin dose of 30 mg/kg/day, the odds ratio (95% confidence interval) for coronary artery abnormalities was 1.40 (1.13-1.75) at 5 mg/kg/day. An aspirin dose of ≥ 30 mg/kg/day did not significantly change the odds ratio for coronary artery abnormalities. Intravenous immunoglobulin resistance was significantly lower at a dose of 60 mg/kg/day or higher. CONCLUSION:  The results showed no significant association between aspirin escalation over standard-dose and coronary artery abnormalities in patients with acute KD. High-dose aspirin showed the potential to reduce hospital stay and medical costs without increasing complications. WHAT IS KNOWN: • Aspirin is used as a standard treatment together with intravenous immunoglobulin for acute Kawasaki disease (KD). However, few studies have shown the most effective dosage of aspirin to prevent coronary artery abnormalities (CAAs). WHAT IS NEW: • There was no significant association between aspirin dose escalation and CAAs in patients with acute KD.