Pathogenesis and management of Kawasaki disease

COVID-19 in patients with anemia and haematological malignancies: risk factors, clinical guidelines, and emerging therapeutic approaches

Extensive research in countries with high sociodemographic indices (SDIs) to date has shown that coronavirus disease 2019 (COVID-19) may be directly associated with more severe outcomes among patients living with haematological disorders and malignancies (HDMs). Because individuals with moderate to severe immunodeficiency are likely to undergo persistent infections, shed virus particles for prolonged periods, and lack an inflammatory or abortive phase, this represents an overall risk of morbidity and mortality from COVID-19. In cases suffering from HDMs, further investigation is needed to achieve a better understanding of triviruses and a group of related variants in patients with anemia and HDMs, as well as their treatment through vaccines, drugs, and other methods. Against this background, the present study aimed to delineate the relationship between HDMs and the novel COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Besides, effective treatment options for HDM cases were further explored to address this epidemic and its variants. Therefore, learning about how COVID-19 manifests in these patients, along with exploiting the most appropriate treatments, may lead to the development of treatment and care strategies by clinicians and researchers to help patients recover faster. Video Abstract.

A Challenging Diagnosis of Kawasaki Disease Shock Syndrome Complicated by Bilateral Pleural Effusion: A Case Report and Literature Review

Kawasaki disease (KD) is an acute illness primarily affecting children under the age of five. It is characterized by fever and inflammation of small to medium-sized arteries. This case report presents the case of a nine-year-old boy with KD who developed Kawasaki disease shock syndrome (KDSS) complicated by bilateral pleural effusion, which is a rare occurrence. KDSS is defined as KD accompanied by low blood pressure or signs of inadequate blood flow, leading to increased cardiovascular complications. The patient exhibited typical KD symptoms, including conjunctivitis, mucosal changes, rash, extremity swelling, and lymphadenopathy. Additionally, he presented with shock symptoms, such as hypotension and tachycardia. Laboratory findings showed elevated inflammatory markers. Prompt diagnosis and treatment are crucial to prevent coronary artery lesions and other severe complications. The patient received intravenous immunoglobulin and showed significant improvement, with resolution of fever and respiratory distress. Follow-up echocardiography revealed normal results. While pulmonary involvement in KD is rare, the presence of bilateral pleural effusion underscores the challenges in diagnosing KDSS. Early recognition and management are essential for favorable outcomes in KD and its complications.

Pediatric multisystem inflammatory syndrome associated with COVID-19: Insights in pathogenesis and clinical management

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been a major challenge to be faced in recent years. While adults suffered the highest morbidity and mortality rates of coronavirus disease 2019, children were thought to be exclusively asymptomatic or to present with mild conditions. However, around April 2020, there was an outbreak of a new clinical syndrome related to SARS-CoV-2 in children - multisystemic inflammatory syndrome in children (MIS-C) - which comprises a severe and uncon-trolled hyperinflammatory response with multiorgan involvement. The Centers for Disease Control and Prevention considers a suspected case of MIS-C an individual aged < 21 years presenting with fever, high inflammatory markers levels, and evidence of clinically severe illness, with multisystem (> 2) organ involvement, no alternative plausible diagnoses, and positive for recent SARS-CoV-2 infection. Despite its severity, there are no definitive disease management guidelines for this condition. Conversely, the complex pathogenesis of MIS-C is still not completely understood, although it seems to rely upon immune dysregulation. Hence, in this study, we aim to bring together current evidence regarding the pathogenic mechanisms of MIS-C, clinical picture and management, in order to provide insights for clinical practice and implications for future research directions.

Scrotal pain as a novel symptom of multisystem inflammatory syndrome in children (MIS-C): Report from Riyadh, Saudi Arabia

A previously healthy child, presented with severe abdominal and scrotal pain with scrotal swelling for five days. There was associated fever, vomiting, and diarrhea. There was history of COVID-19 infection in the previous month. The patient was febrile (39°C), and in pain. His other vitals were unremarkable. Testicular torsion and appendicitis were ruled out by ultrasound. Abdominal CT scan showed signs indicating terminal ileitis. His MIS-C panel revealed elevated inflammatory markers and cardiac enzymes and positive SARS-CoV-2 IgG levels. All cultures and RT-PCR COVID-19 were negative. Echocardiogram showed only minor mitral and tricuspid regurgitation. The patient was diagnosed as a case of MIS-C. and recovered completely on management. Our patient showed an inexplicable previously unreported complaint of scrotal pain and swelling as a symptom of MIS-c. Further research tackling MIS-C's different presentations and comparing the efficacy of the different treatment methods will help us better manage this disease.

Thymic stromal lymphopoietin induces platelet mitophagy and promotes thrombosis in Kawasaki disease

Kawasaki disease (KD) is an acute systemic vasculitis primarily affecting infants and children. Activated platelets predispose patients to coronary artery structural lesions that may lead to thrombotic cardiovascular events. To discover potential proteins underlying platelet activation in KD, we conducted a protein chip assay of 34 cytokines and discovered thymic stromal lymphopoietin (TSLP) was aberrantly expressed, which remained elevated after intravenous immunoglobulin G (IVIG) treatment and during convalescence in KD patients in comparison to healthy controls. Enzyme-linked immunosorbent assay (ELISA) corroborated the upregulation of TSLP in KD patients, which was exacerbated in convalescent patients complicated with thrombosis. TSLP receptors on platelets were also significantly upregulated in KD patients complicated with thrombosis. Platelet activation, apoptosis, and mitochondrial autophagy (mitophagy) were increased in convalescence KD patients complicated with thrombosis. In vitro, TSLP induced platelet activation and platelet mitophagy in healthy blood donors, as observed in KD patients. TSLP, similar to mitophagy agonist carbonyl cyanide 3-chlorophenyl hydrazone (CCCP), promoted thrombosis, which was attenuated by the mitophagy inhibitor Mdivi-1. Co-immunoprecipitation in TSLP-treated platelets revealed TSLP receptor (TSLPR) bound to mitophagy regulators, Parkin and Voltage Dependent Anion Channel Protein 1 (VDAC1).Thus, our results demonstrated that TSLP induced platelet mitophagy via a novel TSLPR/Parkin/VDAC1 pathway that promoted thrombosis in KD. These results suggest TSLP as a novel therapeutic target against KD-associated thrombosis.

Incidence of Kawasaki Disease Before and After the COVID-19 Pandemic in Japan: Results of the 26th Nationwide Survey, 2019 to 2020

IMPORTANCE

Global studies have reported that the incidence of Kawasaki disease (KD) declined during the COVID-19 pandemic. These studies suggest that the global pandemic and its accompanying mitigation measures may provide an important opportunity to explore the hypothesis of a KD pathogenesis.

OBJECTIVE

To compare changes in KD incidence in Japan before and after the start of the COVID-19 pandemic.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study was conducted using the data set from Japan's 26th nationwide KD survey that obtained information on patients who were diagnosed with KD in Japan from January 1, 2019, through December 31, 2020.

MAIN OUTCOMES AND MEASURES

Kawasaki disease incidence rates were calculated by referring to the national population data in the vital statistics data for Japan.

RESULTS

A total of 28 520 patients were identified (16 236 male individuals [56.9%]; median [IQR] age, 26 [14-44] months). A total of 17 347 patients were diagnosed with KD in 2019 and 11 173 were diagnosed in 2020, representing a 35.6% reduction in the number of patients diagnosed in 2020 compared with the previous year. Patient distributions for days of illness at the first hospital visit were almost identical in 2019 and 2020, suggesting that the decrease in KD incidence likely was not associated with pandemic-related delays in seeking treatment. The proportion of patients diagnosed with KD who were younger than 12 months was significantly larger in 2020 than in 2019 (21.6% vs 19.4%; P < .001). Compared with KD incidence among younger patients, the incidence among those 24 months and older declined rapidly after initiation of COVID-19 special mitigation measures, with a greater percentage reduction (58.3% reduction in July), but rebounded faster after the end of the special mitigation period. By contrast, the incidence among patients younger than 12 months declined moderately after the initiation of the special mitigation period, with a lower percentage reduction (40.3% reduction in October), and rebounded at a later phase.

CONCLUSIONS AND RELEVANCE

In this cohort study, the number of patients diagnosed with KD decreased by approximately one-third across Japan in 2020, with no indication that parents avoided a hospital visit. Differences in KD incidence reduction patterns before and after the initiation of COVID-19 pandemic mitigation measures were found in patients with KD aged younger than 12 months compared with those 24 months or older, suggesting a potential KD pathogenesis involving transmission among children.

Kawasaki Disease Shock Syndrome Presented with Giant Coronary Artery Dilatation - Presentation of Two Cases and a Literature Review

Background

Kawasaki disease is an acute, self-limited vasculitis of childhood characterized by fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develop in approximately 15 to 25% of untreated children with the disease and may lead to myocardial infarction, sudden death, or ischemic heart disease. Despite an overlap of clinical features with toxic shock syndrome, children with Kawasaki disease generally do not develop shock.

Objective

Here we present two adolescent boys who had KDSS and discuss their differentiating features from MIS-C.

Case reports

Two adolescent children presented with a toxic shock-like illness, and were subsequently diagnosed with Kawasaki disease shock syndrome when coronary artery abnormalities were found on transthoracic echocardiography.

Conclusion

Pediatricians and paediatric cardiologists alike should be aware of this potentially severe form of manifestation of the Kawasaki disease which needs to be differentiated from the multisystem inflammatory syndrome in children.

COVID-19 and New Onset IgA Vasculitis: A Systematic Review of Case Reports

INTRODUCTION

Immunoglobulin A vasculitis is historically more commonly found in children after certain viral infections such as Epstein-Barr, varicella virus, and parvovirus B19. COVID-19 has not been formally established in literature as a trigger for immunoglobulin A vasculitis. However, a main pathogenetic mechanism of COVID-19 is vascular damage, which makes it likely that vasculitis associated with COVID-19 (ie, COVID-19-mediated immunoglobulin A vasculitis) could be biologically plausible, with serious implications, especially for adults. The purpose of this review is to assist emergency nurses in gaining knowledge on the pathophysiology, symptoms, and treatment of COVID-19-mediated immunoglobulin A vasculitis.

METHODS

A systematic search for case reports of COVID-19-associated immunoglobulin A vasculitis was conducted in the PubMed and Scopus electronic databases. The search terms used were COVID-19, coronavirus 2019, SARS COVID-19, and IgA vasculitis, case reports. The following were the inclusion criteria: publication dates between December 1, 2019, and December 1, 2021; full-text article, clinical case studies, and letters to the editor available electronically in English. The following were exclusion criteria: a summary of reports and newspaper publications.

RESULTS

Only 13 clinical cases met the inclusion criteria. The median age of patients described in the case reports were 38.1 years. Of them, 3 children were less than 5 years old. Twelve patients were male. In 7 of 13 cases of immunoglobulin A vasculitis, renal involvement was found.

DISCUSSION

The analysis of published clinical cases showed that COVID-19-associated immunoglobulin A vasculitis affected mostly adults and was characterized by a more severe course because of renal involvement. COVID-19 may be a possible trigger for immunoglobulin A-related disorders. More research is needed to better understand the relationship between immunoglobulin A vasculitis and COVID-19.

Ambient Air Pollution and Kawasaki Disease in Korean Children: A Study of the National Health Insurance Claim Data

Background

Kawasaki disease (KD) is a systemic vasculitis of unknown etiology that primarily affects children under 5 years of age. Some researchers suggested a potential triggering effect of air pollution on KD, but the findings are inconsistent and limited by small sample size. We investigated the association between ambient air pollution and KD among the population of South Korea younger than 5 years using the National Health Insurance claim data between 2007 and 2019.

Methods and Results

We obtained the data regarding particulate matter ≤10 or 2.5 µm in diameter, nitrogen dioxide, sulfur dioxide, carbon monoxide, and ozone from 235 regulatory monitoring stations. Using a time‐stratified case‐crossover design, we performed conditional logistic regression to estimate odds ratios (OR) of KD according to interquartile range increases in each air pollutant concentration on the day of fever onset after adjusting for temperature and relative humidity. We identified 51 486 children treated for KD during the study period. An interquartile range increase (14.67 μg/m³) of particulate matter ≤2.5 µm was positively associated with KD at lag 1 (OR, 1.016; 95% CI, 1.004–1.029). An interquartile range increase (2.79 ppb) of sulfur dioxide concentration was associated with KD at all lag days (OR, 1.018; 95% CI, 1.002–1.034 at lag 0; OR, 1.022; 95% CI, 1.005–1.038 at lag 1; OR, 1.017; 95% CI, 1.001–1.033 at lag 2). Results were qualitatively similar in the second scenario of different fever onset, 2‐pollutant model and sensitivity analyses.

Conclusions

In a KD‐focused national cohort of children, exposure to particulate matter ≤2.5 µm and sulfur dioxide was positively associated with the risk of KD. This finding supports the triggering role of ambient air pollution in the development of KD.

Deep Learning-Based Approach to Automatically Assess Coronary Distensibility Following Kawasaki Disease

Kawasaki disease is an acute vasculitis affecting children, which can lead to coronary artery (CA) aneurysms. Optical coherence tomography (OCT) has identified CA wall damage in KD patients, but it is unclear if these findings correlate with any distensibility changes in the CA and how these changes evolve over time. This paper seeks to establish the link between OCT findings and vessel distensibility with a novel deep learning coronary artery segmentation system and use the segmentation framework to automatically analyze the temporal evolution of coronary stiffness over many years. 27 KD patients underwent catheterization with coronary angiography of the left coronary artery (LCA), followed by OCT of proximal and distal segments of the LCA. Changes in the CA caliber over the cardiac cycle were measured automatically and compared against OCT findings suggestive of KD-related vascular damage. In addition, 34 KD patients with regressed or persistent CA aneurysms were followed with serial CA angiography over an average of 14.5 years. Distensibility changes were calculated using a deep learning coronary artery segmentation framework and evaluated longitudinally. Distensibility in the coronary arteries after KD negatively correlated with increasing severity of OCT findings of KD-related vessel damage. KD patients have a significant increase in CA wall stiffness at 1 year after diagnosis, which then plateaus subsequently, compared to controls. Also, patients with persistent CA aneurysms have a statistically significant increase in wall stiffness over time in comparison to those with regressed CA aneurysms. Distensibility changes in the CA of KD patients calculated using our automated deep learning approach correlates with the severity of OCT findings of KD-related CA damage. This decreased distensibility peaks at 1 year in KD patients when following longitudinally and is more severe in those with persistent CA aneurysms.

Evaluation of Arterial Functions and Carotid Intima Media Thickness in Children During Mid-Term Follow-Up After Kawasaki Disease

OBJECTIVE

Kawasaki disease (KD) is a multisystemic vasculitis of medium- and small-sized arteries. The involvement of the coronary arteries may lead to long-term cardiovascular sequelae. We studied the elasticity of the aorta and the common carotid artery (CCA), flowmediated dilatation of the brachial artery, and carotid intima media thickness, as well biomarkers such as high-sensitivity C-reactive protein (hs-CRP) and elastin, as useful indicators of cardiovascular risk in patients, following KD.

METHODS

The study group consisted of 26 patients with a history of KD, and 26 healthy children. Echocardiography, and carotid and brachial ultrasound studies were performed. Plasma hs- CRP and elastin levels were studied in both groups.

RESULTS

The stiffness indices (SI) obtained from the aortic arch, abdominal aorta, and the CCA were increased in the patients, compared to the controls. Distensibility was decreased at the sinus of Valsalva, the sinotubular junction, the aortic arch, and the ascending aorta, compared to the control group. Flow-mediated dilatation (FMD) was lower in the patients than in the controls. The age of the patients had a negative correlation to distensibility of the aortic arch and abdominal aorta, and a positive correlation to the stiffness of the aortic arch. Follow-up duration correlated positively to stiffness of the aortic arch. Carotid intima-media thickness (CIMT), serum hs-CRP, and elastin levels did not differ between the groups.

CONCLUSION

Increased aortic and carotid stiffness and decreased aortic distensibility suggest impaired arterial functions following KD. Long-term follow-up and monitorization early in cardiovascular disease is needed.

Predictive Role of IL-2R and IL-10 in the Anti-inflammatory Response and Antiplatelet Therapy of Kawasaki Disease: A Retrospective Study

To date, Kawasaki disease (KD) has only been able to be diagnosed and evaluated using clinical characteristics. Additionally, the therapeutic effect and cardiovascular complications could not be verified until its occurrence. The present retrospective study analyzed the dynamic alterations of inflammatory cytokines, platelet (PLT) count, and subgroups of lymphocytes, such as cluster of differentiation (CD) 8+ T cells and CD19+ B cells, under different conditions in 64 children with KD. The percentage distribution of lymphocyte subgroups and the altered neutrophil lymphocyte ratio demonstrated that the inflammatory response was dominated by the B cell-mediated humoral immune response before intravenous immunoglobulin (IVIG) treatment, but mainly by T cells via cellular cytotoxic effects after IVIG treatment. Among the different types of inflammatory cytokines, the results of the present study revealed that the altered levels of interleukin-2 receptor (IL-2R) and interleukin-10 (IL-10) were closely associated with the percentage of CD8+ T cells and CD19+ B cells. Additionally, the two cytokines exhibited more sensitive fluctuations based on the status of the children with KD in various circumstances compared with other indexes, such as the percentages of CD8+ T cells and CD19+ B cells or the PLT count. These results suggested that children with KD who are ≥4 years old may benefit from IVIG but will not benefit from decreased platelet activation or suffer less cardiovascular complications. Additionally, starting clopidogrel usage earlier as an antiplatelet strategy should be considered based on the observed continuous rise in the PLT count in children with KD receiving IVIG. In conclusion, dynamically monitoring the levels of IL-2R and IL-10 has the potential to provide indications of the intensity and development of the inflammatory response in children with KD and may contribute to the early prediction and adjustment of pathological and pharmacological effects of therapy.

Kawasaki Disease and Pediatric Infectious Diseases During the Coronavirus Disease 2019 Pandemic

OBJECTIVE

To assess the epidemiologic association between Kawasaki disease and common pediatric infectious diseases (PIDs) identified during the coronavirus disease 2019 (COVID-19) pandemic period to confirm whether the infection-triggered theory is a plausible hypothesis for the pathogenesis of Kawasaki disease.

STUDY DESIGN

A retrospective epidemiologic study was conducted using datasets obtained from Web-based surveillance of Kawasaki disease and PIDs in Japan. We compared weekly numbers of patients who developed Kawasaki disease and specific PIDs between 2020 and 2017-2019 and evaluated the association between the percent reduction in the number of patients with these diseases.

RESULTS

A total of 868 patients developed Kawasaki disease in 2020. During the social distancing period in 2020, the number of patients with Kawasaki disease was approximately 35% lower than in 2017-2019. Time from the onset of Kawasaki disease until the first hospital visit did not differ significantly among the examined years. The proportion of older children with Kawasaki disease decreased more than that of infants with Kawasaki disease (age <1 year), resulting in a significant difference in the proportion of infant patients between 2020 and 2017-2019 (24% vs 19%; P < .01). The number of patients with incomplete Kawasaki disease was unchanged from that of previous years. The weekly percent reduction in patient numbers differed between Kawasaki disease and PIDs during 2020, with no strong correlation between the 2 diseases.

CONCLUSIONS

Our data indicate that parents of patients with Kawasaki disease did not avoid hospital visits during the COVID-19 pandemic period. The findings indicate the possibility that triggering Kawasaki disease might be associated with presently unidentified respiratory pathogen(s) that potentially might be acquired from both within and outside the household.

Is there any association between asthma and Kawasaki disease? A systematic review and meta-analysis

OBJECTIVE

Shared immune factors are involved in the pathogenesis of asthma and Kawasaki disease (KD). Consequently, several observational studies have explored an association between KD and asthma. This systematic review and meta-analysis aimed to explore the association between KD and asthma.

METHODS

PubMed and Embase databases were searched for cross-sectional, case-control and cohort studies that investigated the association between KD and asthma. The first author, publication year, study type, sample size, and participant demographics were retrieved. The association between KD and asthma was expressed by the odds ratio (OR) and 95% confidence interval (CI).

RESULTS

Eleven studies were eligible in the systematic review. The crude ORs (cORs) were extracted from 11 studies, and seven of them also provided adjusted ORs (aORs). The cORs between KD and asthma was 1.53 (95% CI, 1.29-1.81). After adjustment for some confounding factors (age, sex, region), asthma also had an association with KD (aOR, 1.08; 95% CI, 1.00-1.17). The subgroup analyses showed the study design and study location to influence between-study heterogeneity. Analyses of aOR values revealed that asthma onset before KD onset does not appear to increase KD prevalence, whereas people suffering from KD could increase the prevalence of developing asthma.

CONCLUSION

Our meta-analysis suggested a possible association between preceding KD and asthma onset, but care must be taken when interpreting this result. Prospective cohort studies are needed to assess a causal relationship between these two diseases.

A Retrospective Cohort Study of Intravenous Immunoglobulin Therapy in the Acute Phase of Kawasaki Disease: The Earlier, the Better?

Background

Although intravenous immunoglobulin (IVIG) is expected to prevent coronary artery abnormalities of Kawasaki disease (KD) in the acute phase, the timing and effectiveness of IVIG remain to be determined. The association of timing of IVIG administration in KD patients with coronary artery abnormalities is evaluated in this cohort study.

Methods

We systematically studied KD patients from two participating institutions between 2015 and 2017. To reveal the effectiveness of IVIG treatment, these patients were classified into four groups regarding the time of IVIG treatment. Primary outcome was coronary artery abnormalities by echo at diagnosis and 12 months follow-up; secondary outcomes included inflammatory markers.

Results

A total of 1281 patients were included in this study. The best time of IVIG treatment cut-off values in 12 months follow-up for predicting coronary artery abnormalities was days 7.5 of illness onset. According to the best time of IVIG treatment cut-off values, all patients were classified into 4 groups. Group 1 was defined as earlier IVIG treatment administration on days ≤4 of the illness (n = 77). Group 2 was defined with days 5-7 (n = 817), group 3 with days 8-10 (n = 249), group 4 with days >10 (n = 138). A greater proportion of IVIG-resistant KD patients were group 4 than the other three groups, and there were significant differences (p < 0.05). The incidence of coronary artery lesions (CALs) and coronary artery aneurysms (CAAs) in group 3 and group 4 was higher than that in group 1 (p < 0.05) and group 2 (p < 0.05) during a 12-month follow-up. Additionally, the incidence of CALs in group 1 was higher than that in group 2 but without statistical significance (p > 0.05). The OR was significantly higher for those who started IVIG administration more than 7 days from the onset was positively associated with the occurrence of CALs (OR, 5.3; 95% CI, 2.0-13.9) and CAAs (OR, 13.5; 95% CI, 2.9-14.1) 12 months after initial onset. Multivariate regression revealed that the timing of IVIG treatment and IVIG-resistance was independent risk factors of CALs.

Conclusions

IVIG treatment less than 7 days after illness onset are found to be sufficient for preventing developing coronary artery abnormalities in KD patients. Earlier IVIG treatment administration within 4 days may not increase the higher incidence of coronary artery abnormalities and IVIG resistance (Chinese Clinical Trial Registry:ChiCTR1800015800).

Kawasaki Disease Shock Syndrome: A Nine-Year-Old Girl With Atypical Presentation of Kawasaki Disease in Emergency Department

Kawasaki disease (KD) is an acute rheumatological illness usually affecting children between six months and five years of age. It is a vasculitis syndrome of medium-sized vessels that has typical clinical characteristics such as fever, rash, cervical lymphadenopathy, conjunctivitis, and mucosal changes. However, sometimes, it may present with the features of shock when it is known as Kawasaki disease shock syndrome (KDSS). The actual etiology of this disease is still unknown. The primary treatment of this disease is aspirin and intravenous immunoglobulin (IVIG). The most common and serious complication of KD is cardiac complications which can be avoided by IVIG if given on time. KDSS is the other rare but serious early complication that can be presented to the ED as an initial presenting feature. Early diagnosis of KDSS in the ED and its treatment is very important to prevent early and late complications, including cardiac complications of this disease. Although the usual age group for this disease is under five years, here we have presented a rare case of KDSS in a nine-year-old female child.

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.

Association of 8p22-23-rs2254546 Genotypes with Coronary Artery Status and Resistance to Intravenous Immunoglobulin in Iranian Children with Kawasaki Disease

Background: Kawasaki disease (KD) is a frequent cause of acquired heart disease in infants and young children, which may be triggered by infectious agents, with the highest incidence in Asian countries. Several genotypes are identified as susceptibility genes for KD, but none is known in the Iranian population. Objectives: Due to the racial differences in the frequency and significance of the identified genes, we aimed to investigate the 8p22-23-rs2254546 genotypes in a sample of Iranian children and their association with aneurysm and resistance to treatment. Methods: In this prospective cross-sectional study, 100 children with KD as the sample group were compared with 100 matched unrelated healthy Iranian children with no history of KD or immune-related disease. The control subjects were ethnically recruited from the same hospital at the time of a routine physical examination. The 8p22-23-rs2254546 genotypes were analyzed using the polymerase chain reaction (PCR) and direct sequencing techniques, and the frequency of the three genotypes (GA, AA, and GG) was reported. Finally, the frequency of aneurysm and IVIG resistance was reported, and their associations with 8p22-23-rs2254546 genotypes were tested by SPSS software. Results: Of 100 patients with a mean age of 1.9 ± 1.7 (0.1 - 10.2) years, 57% were boys and 43% were girls. Of them, 62% had GG, 30% GA, and 8% AA genotypes. Besides, 21% of the studied patients were resistant to IVIG, and 19% had aneurysm, but resistance to IVIG and aneurysm was not associated with GG and GA genotypes of 8p22-23-rs2254546 (P = 0.29 and 0.88, respectively). Conclusions: The majority of the children with KD were shown to have this genetic susceptibility, which shows the importance of the 8p22-23-rs2254546 genotype in Iranian children. However, this genotype was not associated with the risk of resistance to IVIG and aneurysm.

Multisystem inflammatory syndrome in pediatric COVID-19 patients: a meta-analysis

BACKGROUND

We aimed to systematically review the clinical and laboratory features of patients with the multisystem inflammatory syndrome in pediatrics diagnosed during the COVID-19 pandemic.

DATA SOURCES

A literature search in Web of Science, PubMed, Scopus, and Science Direct was made up to June 29, 2020.

RESULTS

Analysis of 15 articles (318 COVID-19 patients) revealed that although many patients presented with the typical multisystem inflammatory syndrome in pediatrics, Kawasaki-like features as fever (82.4%), polymorphous maculopapular exanthema (63.7%), oral mucosal changes (58.1%), conjunctival injections (56.0%), edematous extremities (40.7%), and cervical lymphadenopathy (28.5%), atypical gastrointestinal (79.4%) and neurocognitive symptoms (31.8%) were also common. They had elevated serum lactic acid dehydrogenase, D-dimer, C-reactive protein, procalcitonin, interleukin-6, troponin I levels, and lymphopenia. Nearly 77.0% developed hypotension, and 68.1% went into shock, while 41.1% had acute kidney injury. Intensive care was needed in 73.7% of cases; 13.2% were intubated, and 37.9% required mechanical ventilation. Intravenous immunoglobulins and steroids were given in 87.7% and 56.9% of the patients, respectively, and anticoagulants were utilized in 67.0%. Pediatric patients were discharged after a hospital stay of 6.77 days on average (95% CI 4.93-8.6).

CONCLUSIONS

Recognizing the typical and atypical presentation of the multisystem inflammatory syndrome in pediatric COVID-19 patients has important implications in identifying children at risk. Monitoring cardiac and renal decompensation and early interventions in patients with multisystem inflammatory syndrome is critical to prevent further morbidity.

Increased Risk of Kawasaki Disease in Infants Born of Mothers With Immune Disorders

Introduction: Genetic susceptibility and immune dysregulation play important roles in the pathogenesis of Kawasaki disease (KD). However, it is still unclear whether KD causes immune disorder later in life or whether inherited susceptibility to immune disorders causes KD. The aim of this study was to elucidate whether inherited immune disease properties from mothers increase the risk of KD from a population-based perspective. Method: Taiwan's National Health Insurance Research Database was the main data source in this study. Parents and children were linked using the Taiwan Maternal and Child Health Database. Patients diagnosed with KD and younger than 18 years from 2004 to 2015 were enrolled as the study population. The control group was randomly selected from individuals without the diagnosis of KD matched by age, index year, sex, and urbanization level at a ratio of 1 to 10. The prevalence of maternal autoimmune and allergic diseases was compared between groups. Results: In total, 7,178 children were found to have been diagnosed with Kawasaki disease. Then 71,780 children matched by index year, gender, and urbanization were randomly selected to serve as the control group. Children born from mothers with asthma and allergic rhinitis had a higher risk of developing KD. Children of mothers with an autoimmune disorder had a significantly increased tendency to develop KD. Maternal numbers of autoimmune disorders showed a dose-dependent relationship with KD incidence. Conclusion: This is the first population-based study to investigate maternal immune diseases and the risk of KD in their children. Children of mothers with immune disorders tend to have a higher risk of KD.

Role of Neutrophils in Systemic Vasculitides

Neutrophils and neutrophil extracellular traps (NETs) contribute to the pathogenesis of many autoimmune diseases, including vasculitis. Though neutrophils, and NETs, can break self-tolerance by being a source of autoantigens for autoantibodies in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, playing a key role in driving the autoimmune response, the role of neutrophils and NETs in large vessel vasculitis, including giant cell arteritis (GCA), is not well understood. In this review, we summarize the current insight into molecular mechanisms contributing to neutrophil-mediated pathology in small and medium vessel vasculitis, as well as provide potential translational perspectives on how neutrophils, and NETs, may partake in large vessel vasculitis, a rare disease entity of unclear pathogenesis.

Effects of Non-Coding RNA on Regulatory T Cells and Implications for Treatment of Immunological Diseases

Regulatory T cells (Tregs) are essential for regulating immune reactions and maintaining immune homeostasis. Non-coding RNAs (ncRNAs), including microRNAs and long non-coding RNAs, usually do not encode proteins but regulate intracellular biological processes at post-transcriptional levels. These ncRNAs have been demonstrated as key post-transcriptional regulators in the commitment of Tregs lineage and the plasticity of Tregs function. These ncRNAs can further be manipulated to benefit human immunological disorders caused by Tregs dysfunction. This review summarizes the effects of ncRNAs on Tregs and their potentials to be targets or approaches for the treatment of immunological diseases involving Tregs.

[Value of ginsenoside Rb1 in alleviating coronary artery lesion in a mouse model of Kawasaki disease]

OBJECTIVE

To study the effect and related signaling pathways of ginsenoside Rb1 in the treatment of coronary artery lesion (CAL) in a mouse model of Kawasaki disease (KD).

METHODS

BALB/c mice were randomly divided into a control group, a model group, an aspirin group, a low-dose ginsenoside Rb1 group (50 mg/kg), and a high-dose ginsenoside Rb1 group (100 mg/kg), with 12 mice in each group. All mice except those in the control group were given intermittent intraperitoneal injection of 10% bovine serum albumin to establish a mouse model of KD. The mice in the aspirin group, the low-dose ginsenoside Rb1 group, and the high-dose ginsenoside Rb1 group were given the corresponding drug by gavage for 20 days after modeling. Hematoxylin and eosin staining was used to observe the pathological changes of coronary artery tissue. ELISA was used to measure the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum and coronary artery tissue. Western blot was used to measure the relative expression levels of proteins involved in the regulation of the AMPK/mTOR autophagy signaling pathway and the PI3K/Akt oxidative stress signaling pathway in coronary artery tissue.

RESULTS

The observation of pathological sections showed that compared with the model group, the high-dose ginsenoside Rb1 group had significant improvement in the symptoms of vascular wall thickening, intimal edema, fiber rupture, and inflammatory infiltration of endothelial cells. Compared with the control group, the model and low-dose ginsenoside Rb1 groups had significant increases in the levels of TNF-α, IL-6, and IL-1β in serum and coronary artery tissue (P<0.05); the model group had significant increases in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 in coronary artery tissue (P<0.05) and significant reductions in the expression levels of P-PI3K/PI3K, P-AKT/AKT, and P-GSK-3β/GSK-3β in coronary artery tissue (P<0.05). Compared with the model group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the low- and high-dose ginsenoside Rb1 groups had significant reductions in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 (P<0.05) in a dose-dependent manner between the two groups (P<0.05); the low-dose ginsenoside Rb1 group had no significant change in the expression level of P-PI3K/PI3K (P>0.05) and had significant increases in the expression levels of P-AKT/AKT and P-GSK-3β/GSK-3β (P<0.05), while the high-dose ginsenoside Rb1 group had significant increases in the relative protein expression levels of the above three proteins (P<0.05). Compared with the low-dose ginsenoside Rb1 group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the high-dose ginsenoside Rb1 group had significant increases in the expression levels of P-PI3K/PI3K and P-AKT/AKT (P<0.05).

CONCLUSIONS

Ginsenoside Rb1 can effectively alleviate CAL in a mouse model of KD in a dose-dependent manner, possibly by regulating the AMPK/mTOR/P70S6 autophagy signaling pathway to inhibit CAL inflammation and regulating the PI3K/AKT/GSK-3β oxidative stress signaling pathway to exert a biological activity of protection against coronary artery endothelial cell injury.

[Value of ginsenoside Rb1 in alleviating coronary artery lesion in a mouse model of Kawasaki disease]

OBJECTIVE

To study the effect and related signaling pathways of ginsenoside Rb1 in the treatment of coronary artery lesion (CAL) in a mouse model of Kawasaki disease (KD).

METHODS

BALB/c mice were randomly divided into a control group, a model group, an aspirin group, a low-dose ginsenoside Rb1 group (50 mg/kg), and a high-dose ginsenoside Rb1 group (100 mg/kg), with 12 mice in each group. All mice except those in the control group were given intermittent intraperitoneal injection of 10% bovine serum albumin to establish a mouse model of KD. The mice in the aspirin group, the low-dose ginsenoside Rb1 group, and the high-dose ginsenoside Rb1 group were given the corresponding drug by gavage for 20 days after modeling. Hematoxylin and eosin staining was used to observe the pathological changes of coronary artery tissue. ELISA was used to measure the levels of the inflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in serum and coronary artery tissue. Western blot was used to measure the relative expression levels of proteins involved in the regulation of the AMPK/mTOR autophagy signaling pathway and the PI3K/Akt oxidative stress signaling pathway in coronary artery tissue.

RESULTS

The observation of pathological sections showed that compared with the model group, the high-dose ginsenoside Rb1 group had significant improvement in the symptoms of vascular wall thickening, intimal edema, fiber rupture, and inflammatory infiltration of endothelial cells. Compared with the control group, the model and low-dose ginsenoside Rb1 groups had significant increases in the levels of TNF-α, IL-6, and IL-1β in serum and coronary artery tissue (P<0.05); the model group had significant increases in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 in coronary artery tissue (P<0.05) and significant reductions in the expression levels of P-PI3K/PI3K, P-AKT/AKT, and P-GSK-3β/GSK-3β in coronary artery tissue (P<0.05). Compared with the model group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the low- and high-dose ginsenoside Rb1 groups had significant reductions in the expression levels of P-AMPK/AMPK, P-mTOR/mTOR, and P-P70S6/P70S6 (P<0.05) in a dose-dependent manner between the two groups (P<0.05); the low-dose ginsenoside Rb1 group had no significant change in the expression level of P-PI3K/PI3K (P>0.05) and had significant increases in the expression levels of P-AKT/AKT and P-GSK-3β/GSK-3β (P<0.05), while the high-dose ginsenoside Rb1 group had significant increases in the relative protein expression levels of the above three proteins (P<0.05). Compared with the low-dose ginsenoside Rb1 group, the aspirin group and the high-dose ginsenoside Rb1 group had significant reductions in the levels of TNF-α, IL-6, and IL-1β (P<0.05); the high-dose ginsenoside Rb1 group had significant increases in the expression levels of P-PI3K/PI3K and P-AKT/AKT (P<0.05).

CONCLUSIONS

Ginsenoside Rb1 can effectively alleviate CAL in a mouse model of KD in a dose-dependent manner, possibly by regulating the AMPK/mTOR/P70S6 autophagy signaling pathway to inhibit CAL inflammation and regulating the PI3K/AKT/GSK-3β oxidative stress signaling pathway to exert a biological activity of protection against coronary artery endothelial cell injury.

The Thrilling Journey of SARS-CoV-2 into the Intestine: From Pathogenesis to Future Clinical Implications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a direct impact on the gastrointestinal system, as up to 50% of fecal samples from coronavirus disease 2019 (COVID-19) patients contain detectable viral RNA despite a negative rhino-pharyngeal swab. This finding, together with an intestinal expression of angiotensin conversion enzyme 2 protein, suggests a possible fecal-oral transmission for SARS-CoV-2. Furthermore, gastrointestinal (GI) symptoms are common in COVID-19 patients including watery diarrhea, vomiting-particularly in children-nausea, and abdominal pain. Pathogenesis of SARS-CoV-2 infection presents significant similarities to those of some immune-mediated diseases, such as inflammatory bowel diseases or rheumatoid arthritis, leading to the hypothesis that targeted therapies used for the treatment of immune-mediated disease could be effective to treat (and possibly prevent) the main complications of COVID-19. In this review, we synthesize the present and future impact of SARS-CoV-2 infection on the gastrointestinal system and on gastroenterology practice, hypothesizing a potential role of the "gut-lung axis" and perhaps of the gut and lung microbiota into the interindividual differential susceptibility to COVID-19 19 disease. Finally, we speculate on the reorganization of outpatient gastroenterology services, which need to consider, among other factors, the major psychological impact of strict lockdown measures on the whole population.

The Role of MicroRNAs in Regulatory T Cells

MicroRNAs are a class of conserved, 20 nt-23 nt long, noncoding small RNAs that inhibit expression of their respective target genes in different cell types. Regulatory T cells (Tregs) are a subpopulation of T cells that negatively regulate immune responses, which is essential to immune homeostasis. Recent studies have indicated that microRNAs play an important role in the proliferation, differentiation, and functions of Treg. Here, we review the recent progress in understanding the roles of microRNAs in Treg and their dysregulation in immune-related diseases. This ongoing research continues to expand the understanding of Treg regulation and the mechanisms of immune disorders.

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.

Increased QT Interval Dispersion is Associated with Coronary Artery Involvement in Children with Kawasaki Disease

Objectives

Coronary artery (CA) involvement is the most well known complication of Kawasaki disease (KD). Previous studies have suggested that QT dispersion has a predictive value in diagnosing cardiac ischemia, ventricular arrhythmia, and sudden cardiac death. However, limited data exits regarding the application of QT dispersion in KD. Therefore, we sought to determine whether there is a relationship between QT dispersion and CA involvement in patients with KD.

Methods

We performed a cross-sectional study of all consecutive patients with KD who were followed-up at the Pediatric Rheumatology Department (Pediatrics Center of Excellence affiliated to Tehran University of Medical Sciences, Tehran, Iran) from September 2013 to November 2015. Patients who met the criteria for KD, based on the American Heart Association guideline, were enrolled in the study. We collected data regarding patients' demographics, clinical manifestations, laboratory, and echocardiographic findings.

Results

A total of 70 KD patients were identified, including 43 males (61.4%) and 27 females (38.6%). The median age of patients was 21.0 (11.0-48.0) months. We found statistically significant differences between age, gender, and platelet count among patients with and without CA involvement (p < 0.050). Median corrected QT dispersion in patients with CA involvement calculated from 12 leads in the acute phase was significantly higher compared to the non-CA involvement group (108.0 (89.5-138.5) ms vs. 63.0 (54.0-74.5) ms, respectively (p < 0.001)).

Conclusions

Prolonged QT dispersion (corrected or non-corrected) during the acute and convalescence phases in patients with KD is associated with coronary involvement.

COVID-19 in Children: A Review and Parallels to Other Hyperinflammatory Syndromes

During the COVID-19 pandemic, children have had markedly different clinical presentations and outcomes compared to adults. In the acute phase of infection, younger children are relatively spared the severe consequences reported in adults. Yet, they are uniquely susceptible to the newly described Multisystem Inflammatory Syndrome in Children (MIS-C). This may result from the developmental "immunodeficiency" resulting from a Th2 polarization that starts in utero and is maintained for most of the first decade of life. MIS-C may be due to IgA complexes in a Th2 environment or a Th1-like response to COVID-19 antigens that developed slowly. Alternatively, MIS-C may occur in vulnerable hosts with genetic susceptibilities in other immune and non-immune pathways. Herein, we present a brief overview of the host immune response, virologic and genetic factors, and comparable inflammatory syndromes that may explain the pathophysiology leading to drastic differences in clinical presentation and outcomes of COVID-19 between children and adults.

Global Investigation of Immune Repertoire Suggests Kawasaki Disease Has Infectious Cause

BACKGROUND

Kawasaki disease (KD) severely threatens young children's health worldwide. The pathogenic mechanism of KD has not yet been solved, so there is still debate over whether KD is an infectious disease or an autoimmune disease.Methods and Results:To solve this problem, an immune repertoire analysis of KD was conducted. We collected blood cell RNA samples and prepared them into amplicons with iRepertoire kits. The amplicons were sequenced and analyzed with the iRepertoire pipeline. We first identified KD-specific VJ and VDJ forms that had the potential to serve as biomarkers of KD. In addition, the KD-specific VDJ forms were contributed mostly by immunoglobulin G. The D50 value analysis showed that B-cell diversity in KD is decreased, suggesting unique immunoglobulins are produced in KD. Moreover, V, D and J segment usage in IgA, IgG and IgM was consistent with previous KD studies. Further comparison showed no difference in CDR3 peptide length between KD and fever controls (subjects with fever but not diagnosed as KD), indicting KD had B-cell selection phenomenon that has a non-autoimmune pattern. The comparison of amino acid usage of the CDR3 region demonstrated a preference for hydrophilic amino acids in KD.

CONCLUSIONS

The results of D50 value, VDJ usage and CDR3 peptide length analyses suggested the characteristics of infectious disease for KD.

Kawasaki Disease: The Role of Immune Complexes Revisited

Kawasaki disease (KD) is an inflammatory disease in children associated with vasculitis affecting predominantly the coronary arteries and is now the most common cause of acquired heart disease in children in developed countries. The etiology of KD is unknown but epidemiological studies implicate an infectious agent or toxin, which causes disease in genetically predisposed individuals. The presence of immune complexes (ICs) in the serum of children with KD was established in numerous studies during the 1970s and 80s. More recent genetic studies have identified variation in Fcγ receptors and genes controlling immunoglobulin production associated with KD. In this review we link the genetic findings and IC studies and suggest a key role for their interaction in pathophysiology of the disease.

Tumor necrosis factor-α-308 polymorphism is not associated with Kawasaki disease: A meta-analysis of case-control studies

BACKGROUND

Genetic factors in the pathogenesis of Kawasaki disease (KD) have received a lot of attention during the past decade. Some studies have reported that tumor necrosis factor (TNF)-α-308 polymorphism has been associated with KD. However, there have been inconsonant results among different studies. To increase the power for clarifying the influence of TNF on KD, a meta-analysis of case-control studies were performed.

METHODS

The following databases were searched to identify related studies: PubMed, Embase, Cochrane Library, CNKI, Wanfang, and VIP databases according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Search terms included "Kawasaki disease" or "KD," "tumor necrosis factor-alpha" or "TNF-α," and "polymorphism" or "mutation." Two reviewers independently extracted data and assessed study quality using Newcastle-Ottawa Scale. Odds ratios (ORs) with corresponding 95% confidence intervals (CI) were used to assess the strength of the association. Accounting for heterogeneity, a fixed or random effects model was respectively adopted. Heterogeneity was checked using the Q test and the I statistic. A cumulative meta-analysis was conducted to estimate the tendency of pooled OR. Funnel plots and Egger tests were performed to test for possible publication bias and sensitivity analyses were done to ensure authenticity of the outcome.

RESULTS

Eleven separate studies were suitable for the inclusion criterion. The selected studies contained 2582 participants, including 841 in KD group and 1741controls. The pooled odds ratio of G versus A with the random effect model was 1.09 (95% CI = 0.69-1.70, P = .72) and the genotype effects for GG versus GA+AA was 1.14 (95% CI = 0.68-1.90, P = .62) in the whole population separately. Unfortunately, no significant association was detected between the TNF-α-308 polymorphism and KD risk under allele and genotype model.

CONCLUSION

No association between the TNF-α-308 polymorphism and KD was found in our meta-analysis and further studies with larger sample size and more ethnicities are expected to be conducted in the future to validate the results.

Platelet-Derived Microparticles: A New Index of Monitoring Platelet Activation and Inflammation in Kawasaki Disease

OBJECTIVE

To investigate the dynamic changes of platelet-derived microparticles (PDMP) in Kawasaki disease (KD) and its clinical significance and to study its relationship with intravenous immunoglobulin (IVIG) resistance, inflammatory indicators and aspirin treatment in children with KD.

METHODS

Twenty children with KD were enrolled as the experimental group, while 20 age- and gender-matched children with common febrile disease were included in the control group. Blood samples were drawn before and 7-10 d after IVIG infusion and thereafter at 1, 2, and 3 mo after the onset of KD to estimate the PDMP concentrations by enzyme linked immunosorbent assay (ELISA). C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), procalcitonin (PCT), and cytokines [Interleukin-6 (IL-6), Tumor necrosis factor-α (TNF-α), and Soluble interleukin-2 (sIL-2R)] were also measured.

RESULTS

The level of PDMP in KD children before IVIG was significantly higher than that in controls (P < 0.0001). The PDMP level in KD children decreased significantly at 7 to 10 d after IVIG (P < 0.0001) and then decreased to the lowest level in the course of 1 to 2 mo. Some children's PDMP level rebounded in the course of 3 mo (P = 0.047). In addition, the mean level of PDMP in IVIG-resistant children was higher than that in IVIG-effective children; however, there was no significant difference between the two groups (P = 0.1945). Furthermore, PDMP was positively correlated with hs-CRP, IL-6, and sIL-2R levels, but no correlation was observed with ESR, PCT, and TNF-α levels.

CONCLUSIONS

PDMP can be used as an index to monitor inflammation in children at the acute stage of KD. And the duration of platelet activation in KD is individualized.

P2RY12:rs7637803 TT variant genotype increases coronary artery aneurysm risk in Kawasaki disease in a southern Chinese population

BACKGROUND

Activated-platelet increases the risk of thrombosis in Kawasaki disease (KD) patients with a coronary artery aneurysm (CAA). The ADP pathway is one of the platelet activation and aggregation pathways. The P2RY12 gene encodes the ADP receptor that is highly concentrated on platelets. However, few studies have reported on P2RY12 in relation to KD susceptibility with or without CAA.

METHODS

We recruited 1335 healthy controls and 776 KD patients, including 103 with CAA, and selected five P2RY12 polymorphisms: rs9859538, rs1491974, rs7637803, rs6809699 and rs2046934. The present study focused on the relationship between the P2RY12 polymorphisms and KD with or without CAA.

RESULTS

Among all of the selected polymorphisms, single-locus analysis showed no significant association between the P2RY12 polymorphism and KD susceptibility. However, we found a significant relationship between rs7637803 and CAA risk in KD patients [CT versus CC: odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.22-0.75; p = 0.0041; TT versus CC: OR = 2.90, 95% CI = 1.12-7.46; p = 0.0276]. Stratification analysis by age in KD patients indicated that the rs7637803 TT genotype increased CAA formation risk among children aged (OR = 3.90, 95% CI = 1.42-10.69; p = 0.0081) and increased the onset risk of CAA in males (OR = 6.28, 95% CI = 2.01-19.65; p = 0.0016). The combined effect of the five selected P2RY12 risk genotypes with the KD patients compared to non-mutated P2RY12 genotypes (score: 0) showed that patients with P2RY12 genotype polymorphisms (score: 1-5) had a significantly increased CAA risk (p = 0.0086). Stratification analysis for the severity of CAA found that the rs7637803 TT genotype reduced giant CAA (GCAA) risk (OR = 4.60, 95% CI = 1.70-12.41; p = 0.0026).

CONCLUSIONS

The results of the present study indicate that the P2RY12 rs7637803 genotype might be used as a biomarker to predict the occurrence of GCAA.

State-of-the-art acute phase management of Kawasaki disease after 2017 scientific statement from the American Heart Association

Kawasaki disease (KD) has become the most common form of pediatric systemic vasculitis. Although patients with KD received intravenous immunoglobulin (IVIG) therapy, coronary arterial lesions (CALs) still occurred in 5%-10% of these patients during the acute stage. CALs may persist and even progress to stenosis or obstruction. Therefore, CALs following KD are currently the leading cause of acquired heart diseases in children. The etiology of CALs remains unknown despite more than four decades of research. Two unsolved problems are IVIG unresponsiveness and the diagnosis of incomplete KD. The two subgroups of KD patients with these problems have a high risk of CAL. In April 2017, the American Heart Association (AHA) updated the guidelines for the diagnosis, treatment, and long-term management of KD. Compared with the previous KD guidelines published in 2004, the new guidelines provide solutions to the aforementioned two problems and emphasize risk stratification by using coronary artery Z score systems, as well as coronary severity-based management and long-term follow-up. Therefore, in this study, we merged the AHA Scientific Statement in 2017 with recent findings for Taiwanese KD patients to provide potential future care directions for Taiwanese patients with KD.

High-dose intravenous immunoglobulin is strongly associated with hemolytic anemia in patients with Kawasaki disease

BACKGROUND

Hemolysis is a reported side effect of intravenous immunoglobulin (IVIG) therapy in adults, but pediatric data are scarce. We determined the frequency of IVIG-associated hemolysis in patients with Kawasaki disease (KD) and characterized risk factors for hemolysis. We hypothesized that hemolysis is more common in children with KD than adults with other disorders, and hemolysis risk is related to IVIG dose and degree of inflammation.

STUDY DESIGN AND METHODS

This was an 8-year, single-center, retrospective cohort study. A total of 419 KD patients were identified; 123 had pre- and post-treatment complete blood counts allowing for assessment of anemia. Hemolytic anemia was defined as decrease in hemoglobin after IVIG greater than 1 g/dL with immunohematologic or biochemical studies supporting hemolysis.

RESULTS

123 patients were stratified as having hemolysis (n = 18, 15%) or nonhemolysis (n = 105, 85%). Patients with hemolysis were more likely to have complete versus incomplete KD (65% vs. 39%, p = 0.04) and refractory versus nonrefractory course (78% vs. 16%, p < 0.001). Patients receiving 4 g/kg versus 2 g/kg IVIG were more likely to hemolyze (89% vs. 34%, p < 0.001). Patients with hemolysis had mostly non-O blood group (94%), positive direct antiglobulin tests (89%), and positive eluates (72%). Two-thirds of patients with hemolysis required RBC transfusion.

CONCLUSIONS

Hemolysis occurred in 15% of KD patients evaluated for anemia and is strongly associated with high-dose (4 g/kg) IVIG. KD patients receiving high-dose IVIG should have close hematologic monitoring to identify hemolysis.

Incomplete Kawasaki Disease in an Adult South Asian Patient

Kawasaki disease is an acute multisystemic vasculitis occurring predominantly in children and rarely in adults, with sequelae of potentially life-threatening coronary artery aneurysms. “Incomplete” Kawasaki disease is a novel concept and considered a diagnosis of exclusion as it alludes to patients with fever lasting ⩾5 days and 2 or 3 clinical criteria without another reasonable explanation for the illness. The multidisciplinary team should be vigilant for this oligosymptomatic clinical presentation, specifically within this subgroup despite age and ethnicity, and the syndrome should be considered as a differential diagnosis in challenging cases presenting as infectious or autoimmune disease.

Association between IL-35 and coronary arterial lesions in children with Kawasaki disease

Kawasaki disease (KD) arises due to the acute inflammation and immune system dysfunction. This study investigated the relationship between the serum level of IL-35 and coronary artery lesions (CALs) in patients with KD. We obtained blood samples from 90 children with KD before intravenous immunoglobulin therapy. Levels of IL-35, IL-6, IL-17A, IL-10, MCP-1 and VEGF were measured in 190 cases, including 4 groups: KD with coronary arterial lesions (n = 46), KD without coronary arteries lesions (n = 44), febrile control group (FC, n = 40) and the normal control group (NC, n = 60). White blood cell counts (WBC), red blood cell counts (RBC), hemoglobin, platelet, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and procalcitonin were tested in all subjects. Levels of IL-35, RBC and hemoglobin significantly decreased, and IL-6, IL-17A, IL-10, MCP-1 and VEGF were significantly elevated in the KD group compared with febrile and control groups. IL-35 serum level even decreased, and ESR, IL-6, MCP-1 and VEGF increased in the KD patients with CALs. Serum levels of IL-35 in KD patients were negatively associated with WBC, CRP, IL-6, IL-17A, IL-10, MCP-1 and VEGF in children with KD. IL-35 may have the effect on inhibiting inflammatory process in KD and further preventing KD patients from coronary artery lesion.

A 3-month-old infant with atypical Kawasaki disease

We report a 3-month-old girl who presented with high-grade fever for 3 days. Her initial physical examination was normal. Investigation showed abnormal white cells in her urine. She was diagnosed with a urinary tract infection and received an antibiotic for 1 day. After that, she developed a generalised maculopapular rash over her body. An adverse drug reaction from the antibiotic was suspected, and the patient was referred to our hospital. On admission, she still had fever and was irritable. She was diagnosed with sepsis and given another broad-spectrum antibiotic for 2 days. However, her fever still persisted. An additional thorough physical examination showed redness of her BCG inoculation scar. Consequently, a diagnosis of Kawasaki disease (KD) was made. After she received intravenous immunoglobulin, her fever diminished straight away. This case highlights an unusual manifestation of KD in an uncommonly young age group.

Controversies in diagnosis and management of Kawasaki disease

Kawasaki disease (KD) is a common medium vessel systemic vasculitis that usually occurs in small children. It has a predilection for the coronary arteries, but other medium sized arteries can also be involved. The etiology of this disorder remains a mystery. Though typical presentation of KD is quite characteristic, it may also present as incomplete or atypical disease in which case the diagnosis can be very challenging. As both incomplete and atypical forms of KD can be associated with serious coronary artery complications, the pediatrician can ill afford to miss these diagnoses. The American Heart Association has enunciated consensus guidelines to facilitate the clinical diagnosis and treatment of this condition. However, there are still several issues that remain controversial. Intravenous immunoglobulin remains the cornerstone of management but several other treatment modalities, especially glucocorticoids, are increasingly finding favour. We review here some of the contemporary issues, and the controversies thereon, pertaining to management of KD.

Clinical Outcomes of Low-Dose Methotrexate Therapy as a Second-Line Drug for Intravenous Immunoglobulin-Resistant Kawasaki Disease

PURPOSE

Intravenous immunoglobulin (IVIG) is the standard treatment for Kawasaki disease (KD). However, there is still no standard treatment for IVIG-resistant KD. This study aimed to evaluate the efficacy of low-dose methotrexate (MTX) as a treatment for IVIG-resistant KD.

MATERIALS AND METHODS

We retrospectively analyzed 10-year data for patients with IVIG-resistant KD who were administered MTX at Severance Children's Hospital.

RESULTS

The subjects included 75 patients with KD aged 5 months to 9.2 years who had been administered MTX. Their maximum body temperatures decreased significantly within 24 h of therapy. The patients' C-reactive protein levels were significantly lower 1 week after administering the first dose of MTX than those before treatment. No adverse effect for MTX was observed.

CONCLUSION

MTX treatment of IVIG-resistant KD resulted in rapid defervescence, improvement of clinical symptoms, and normalization of acute-phase reactants in all patients. Thus, MTX could be a candidate treatment for IVIG-resistant KD.

Cardiac Complications, Earlier Treatment, and Initial Disease Severity in Kawasaki Disease

OBJECTIVES

To assess if observed higher observed risks of cardiac complications for patients with Kawasaki disease (KD) treated earlier may reflect bias due to confounding from initial disease severity, as opposed to any negative effect of earlier treatment.

STUDY DESIGN

We used data from Japanese nationwide KD surveys from 1997 to 2004. Receipt of additional intravenous immunoglobulin (IVIG) (data available all years) or any additional treatment (available for 2003-2004) were assessed as proxies for initial disease severity. We determined associations between earlier or later IVIG treatment (defined as receipt of IVIG on days 1-4 vs days 5-10 of illness) and cardiac complications by stratifying by receipt of additional treatment or by using logistic modeling to control for the effect of receiving additional treatment.

RESULTS

A total of 48 310 patients with KD were included in the analysis. In unadjusted analysis, earlier IVIG treatment was associated with a higher risk for 4 categories of cardiac complications, including all major cardiac complications (risk ratio, 1.10; 95% CI, 1.06-1.15). Stratifying by receipt of additional treatment removed this association, and earlier IVIG treatment became protective against all major cardiac complications when controlling for any additional treatment in logistic regressions (OR, 0.90; 95% CI, 0.80-1.00).

CONCLUSIONS

Observed higher risks of cardiac complications among patients with KD receiving IVIG treatment on days 1-4 of the illness are most likely due to underlying higher initial disease severity, and patients with KD should continue to be treated with IVIG as early as possible.

Acetylsalicylic acid for children with Kawasaki disease

Question A 7-year-old child in my office was recently discharged from the hospital after receiving intravenous immunoglobulin for Kawasaki disease. Should I continue treatment with acetylsalicylic acid (ASA), and if so, what is the appropriate dose? Answer The role of ASA for Kawasaki disease during the acute febrile phase has recently been called into question. According to several studies, ASA might reduce the duration of fever but it does not appear to directly reduce the incidence of coronary artery complications. However, with no high-quality randomized controlled trials, the evidence is scarce and more studies with good methodology are needed to determine the value of ASA in the treatment of Kawasaki disease. Currently, guidelines recommending the use of ASA should be followed.

[Not Available]

Question Un enfant de 7 ans qui fréquente ma clinique a récemment reçu son congé de l’hôpital après une administration d’immunoglobuline par voie intraveineuse pour la maladie de Kawasaki. Faut-il poursuivre son traitement à l’acide acétylsalicylique (AAS) et, dans l’affirmative, quelle est la dose appropriée?

Réponse Le rôle de l’AAS pour la maladie de Kawasaki durant la phase fébrile aiguë a récemment été remis en question. Selon diverses études, l’AAS pourrait réduire la durée de la fièvre, mais il ne semble pas réduire directement l’incidence de complications aux artères coronaires. Par ailleurs, en l’absence d’études randomisées contrôlées, les données probantes sont limitées et il faudrait de plus nombreuses études utilisant une bonne méthodologie pour déterminer l’utilité de l’AAS dans le traitement de la maladie de Kawasaki. À l’heure actuelle, il y a lieu de suivre les lignes directrices qui recommandent le recours à l’AAS.

Computed tomography predict regression of coronary artery aneurysm in patients with Kawasaki disease

BACKGROUND/PURPOSE

The study evaluated possible factors influencing the regression of coronary artery aneurysm (CAA) in patients with Kawasaki disease (KD) through electrocardiographically gated cardiac computed tomography (CT).

METHODS

18 patients with KD exhibited CAAs in at least 2 CT examinations conducted from December 2004 to September 2015, and 37 aneurysms were observed. Every aneurysm was corrected through the descending aorta at the origin level of the left main coronary artery under a normal distribution and measured under a fixed window level. These aneurysms were divided into 2 groups according to regression. Clinical symptoms, laboratory data, and imaging characteristics of both groups were analyzed.

RESULTS

All the aneurysms of 4 patients decreased in size, and totally, 14 aneurysms (37%) regressed. CAA regression tends to occur early after disease onset. No significant differences were observed in sex, aneurysm location, and the distance to the orifice between the 2 groups. The aneurysms with no calcification (p = 0.012), smaller diameter (p = 0.004), younger disease onset age (p = 0.048), and ectatic shape (p < 0.001) were more likely to regress according to univariate analysis. Receiver operating characteristic analysis revealed that the possible cut-off point of the maximal diameter to yield the highest sensitivity (91.3%) and specificity (92.9%) to predict CAA regression was 5.6 mm.

CONCLUSION

Calcified CAAs in patients with KD was less likely to regress. The aneurysm size and shape as well as disease onset age were possible factors influencing regression.