齋藤 和由

Acute myocarditis (AM) is an inflammatory disease of the heart muscle that can progress to fulminant myocarditis (FM), a severe and life-threatening condition. The cytokine profile of myocarditis in children, especially in relation to fulminant myocarditis, is not well understood. This study aims to evaluate the cytokine profiles of acute and fulminant myocarditis in children. Pediatric patients diagnosed with myocarditis were included in the study. Cytokine levels were measured using a multiplexed fluorescent bead-based immunoassay. Statistical analysis was performed to compare patient characteristics and cytokine levels between FM, AM, and healthy control (HC) groups. Principal component analysis (PCA) was applied to cytokine groups that were independent among the FM, AM, and HC groups. The study included 22 patients with FM and 14 with AM patients. We identified four cytokines that were significantly higher in the FM group compared to the AM group: IL1-RA (p = 0.002), IL-8 (p = 0.005), IL-10 (p = 0.011), and IL-15 (p = 0.005). IL-4 was significantly higher in the AM group compared to FM and HC groups (p = 0.006 and 0.0015). PDGF-AA, and VEGF-A were significantly lower in the FM group than in the AM group (p = 0.013 and <0.001). Similar results were obtained in PCA. Cytokine profiles might be used to differentiate pediatric FM from AM, stratify severity, and predict prognosis. The targeted therapy that works individual cytokines might provide a potential treatment for reducing the onset of the FM and calming the condition, and further studies are needed.

UNLABELLED: 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.

Multisystem inflammatory syndrome in children (MIS-C) was reported as a severe complication of coronavirus disease 2019; an infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and was suggested to be associated with Kawasaki disease (KD) in terms of severe systemic inflammation and mucocutaneous symptoms. Because severe gastrointestinal symptoms and systemic shock are more frequently observed with MIS-C, patients with mild MIS-C might have been diagnosed with KD. In this study, titers of IgG antibodies against the SARS-CoV-2 S (S-IgG) and N proteins (N-IgG) were measured in 99 serum samples collected from patients with KD treated between January 2020 and December 2021 to evaluate the relationship between KD and SARS-CoV-2 infection. S-IgG were detected in only one patient out of 99 patients. This patient had coronavirus disease 2019 (COVID-19) 10 months before KD onset, and was unlikely MIS-C. According to characters of S-IgG and N-IgG, the patients was unlikely infected with SARS-CoV-2 just before the onset of KD. In addition to this study, the 26th Nationwide Survey and previous studies showed an association between KD and SARS-CoV-2 to be unlikely. In conclusion, SARS-CoV-2 infection was not observed in patients with KD until Delta predominance in Japan by the method of detecting SARS-CoV-2 IgG.

OBJECTIVES: The Gunma score is used to predict the severity of Kawasaki disease (KD), including coronary artery aneurysm (CAA) as a cardiac complication, in Japan. Additionally, the characteristic ratio of ventricular repolarization (T-peak to T-end interval to QT interval [Tp-e/QT]) on a surface electrocardiogram reflects myocardial inflammation. This study aimed to determine whether the Tp-e/QT can be used to predict CAA in children with KD. METHODS: We analyzed chest surface electrocardiograms of 112 children with KD before receiving intravenous immunoglobulin therapy using available software (QTD; Fukuda Denshi, Tokyo, Japan). RESULTS: The Tp-e/QT (lead V5) was positively correlated with the Gunma score (r=0.352, p<0.001). The Tp-e/QT was larger in patients with CAA (residual CAA at 1 month after onset) than in those without CAA (0.314±0.026 versus 0.253±0.044, p=0.003). A receiver operating characteristic curve analysis was performed to assess whether the Gunma score and Tp-e/QT could predict subsequent CAA. The area under the curve of the Gunma score was 0.719 with the cutoff set at 5 points. The area under the curve of the Tp-e/QT was 0.892 with a cutoff value of 0.299. The fit of the prediction models to the observed probability was tested by the Hosmer-Lemeshow test with calibration plots using Locally weighted scatterplot smoothing (LOESS) fit. The Gunma score (p=0.95) and Tp-e/QT (p=0.95) showed a good fit. CONCLUSIONS: The Tp-e/QT is a useful biomarker in predicting coronary aneurysm complications in KD.

We sought to elucidate the risk profiles of patients with Kawasaki disease who developed coronary artery abnormalities through a retrospective analysis with special reference to steroid treatment. Demographics of the patients were obtained from medical records, and characteristics of the coronary artery abnormalities were evaluated by echocardiography and coronary angiography, which included number, location, size, and length of coronary artery abnormalities (we evaluated by cardiac catheterisation with the American Heart Association classification with segments). We divided the patients into two groups based on steroid use and compared their characteristics and the complications of coronary artery abnormalities and cardiac events. A total of 29 patients were diagnosed with coronary artery abnormalities by echocardiography and coronary angiography during the study period (24 male; median age, 24 months [range: 2-84 months]). Eighteen patients were treated with aspirin and intravenous immunoglobulin (63%, non-steroid group), whereas 11 received aspirin and intravenous immunoglobulin plus steroids (37%, steroid group). No significant differences were found in the number and location of coronary artery abnormalities between the steroid and non-steroid groups. However, the size and number of segments for coronary artery abnormalities were significantly larger and shorter, respectively, in the steroid group (z-score: non-steroid group 6.3 versus steroid group 8.7; p < 0.01). The coronary artery abnormality segments under steroid use were also shorter (non-steroid group versus steroid group, two segments versus one segment; p = 0.02). Coronary artery abnormality size was larger in patients who used steroids than that of non-steroids. This study showed that steroid use significantly affected coronary artery abnormality size in patients with Kawasaki disease. However, cardiac complications from coronary artery abnormalities and cardiac events were comparable between the steroid and non-steroid groups. Further prospective, multicentre studies are needed to confirm these findings.

Mutations in transport and Golgi organization 2 homolog (TANGO2) have recently been described as a cause of an autosomal recessive syndrome characterized by episodes of metabolic crisis associated with rhabdomyolysis, cardiac arrhythmias, and neurodegeneration. Herein, we report a case of a one-and-a-half-year-old Japanese girl, born to nonconsanguineous parents, who presented with metabolic crisis characterized by hypoglycemia with hypoketonemia, rhabdomyolysis, lactic acidosis, and prolonged corrected QT interval (QTc) at the age of 6 months. Acylcarnitine analysis during the episode of crisis showed prominent elevation of C14:1, suggesting very-long-chain acyl-CoA dehydrogenase (VLCAD) deficiency. In addition, worsening rhabdomyolysis was observed after intravenous administration of L-carnitine. VLCAD deficiency was initially suspected; however, the enzyme activity in lymphocytes was only mildly decreased at the gene carrier level, and no mutation in the VLCAD gene (ADADVL) was detected. Subsequently, acylcarnitine analysis was nonspecific at 17-h fasting and almost normal during the stable phase. Eventually, a trio whole-exome sequencing revealed a compound heterozygous variant of two novel variants in the TANGO2 gene, a missense variant, and a deletion of exon 7. This is the first case of TANGO2 deficiency in Asians. Our case suggests that elevated C14:1 may be seen in severe metabolic crises and that the use of L-carnitine should be avoided during metabolic crises.

The most effective dosage of intravenous immunoglobulin (IVIG) to prevent coronary artery abnormalities (CAAs) in patients with acute Kawasaki disease (KD) remains unknown. This study aimed to identify the appropriate dose of IVIG to be administered to patients with acute KD, using a national inpatient database in Japan. We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2020. The primary outcome was the proportion of CAAs upon discharge. Secondary outcomes included IVIG resistance, length of stay, and medical costs. Data from 88,223 patients were extracted from the database. We found a U-shaped association between IVIG dose and the proportion of CAA, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% confidence interval [CI]) was 1.34 (1.26-1.43) for 1.8 g/kg and 1.80 (1.29-2.51) for 2.4 g/kg with reference to 2.0 g/kg for CAA. Similarly, IVIG dose had a U-shaped association with the proportion of IVIG resistance, with the bottom of the curve at approximately 2.0 g/kg; the odds ratio (95% CI) was 1.39 (1.36-1.42) for 1.8 g/kg and 8.95 (8.15-9.83) for 2.4 g/kg with reference to 2.0 g/kg for IVIG resistance. Additionally, IVIG dosage was found to have U-shaped associations with the length of stay and medical costs, with the bottom of the curve at approximately 2 g/kg.   Conclusions: IVIG with a dose of 2 g/kg was considered appropriate for the initial treatment of KD. What is Known: • For treatments of acute Kawasaki Disease (KD), IVIG has been the most recommended to reduce fever early and prevent complications of CAAs. Few studies have shown the most effective dosage of IVIG to be administered to prevent CAAs. What is New: • 2 g/kg intravenous immunoglobulin was considered appropriate for the initial treatment of Kawasaki disease.

PURPOSE: Atlantoaxial rotatory fixation (AARF) is a rare complication of acute Kawasaki disease (KD). Early diagnosis and intervention are important for AARF because delayed diagnoses may incur neurological sequelae. However, previous studies on AARF associated with KD are limited, and its clinical characteristics and course are unknown. This study aimed to examine the clinical features and treatment course of KD with AARF using a Japanese national inpatient database. METHODS: Using the Diagnosis Procedure Combination database, we identified KD patients who received intravenous immunoglobulin (IVIG) treatment between July 2010 and March 2020. The clinical characteristics of KD patients with AARF and their risk factors were evaluated using multivariable logistic regression analysis. We also examined the relationship between AARF, the proportion of coronary artery abnormalities (CAAs), IVIG resistance, length of stay and medical costs. RESULTS: We identified 71,913 patients with KD, 166 of whom had AARF. The AARF group had older age, heavier bodyweight and atypical KD. In multivariable analysis, AARF was associated with older age [odds ratio (OR): 1.24; 95% confidence interval (CI): 1.19-1.29], lower body mass index (OR: 0.89; 95% CI: 0.82-0.96) and atypical KD (OR: 1.95; 95% CI: 1.12-3.40). AARF was not associated with CAAs (OR: 0.73; 95% CI, 0.23-2.32) and IVIG resistance (OR: 1.05; 95% CI, 0.74-1.49). However, AARF was associated with higher medical costs (difference, US$1064; 95% CI: 346-1781) and longer hospital stay (difference, 3.1 days; 95% CI: 1.7-4.4). CONCLUSION: AARF in patients with acute KD should be considered if cervical symptoms present in older patients with atypical KD.

UNLABELLED: We describe the case of a young patient with atresia of the right coronary arterial ostium with left ventricular fistula. This was suspected from the abnormality detected on a 12‑lead electrocardiogram (ECG) during a school examination at the time of admission to junior high school and echocardiography findings. This disease may occur due to abnormalities in several molecules that are essential for coronary artery development. In cases of ECG abnormality, and unexplained aortic valve regurgitation and coronary artery abnormalities on echocardiography are detected, this disease should be suspected. LEARNING OBJECTIVE: Coronary artery anomalies have been identified in coronary angiograms. Herein, we describe the case of a young patient with atresia of the right coronary arterial ostium with left ventricular fistula. This disease may be caused by abnormalities in several molecules that are essential molecule for coronary artery development.

PURPOSE: Few studies have compared the effects of low-concentration (5%) and high-concentration (10%) intravenous immunoglobulin (IVIG) preparations for patients with Kawasaki disease (KD) in the acute phase. The purpose of this study was to compare outcomes between low- and high-concentration IVIG preparations in children with KD, using a national inpatient database in Japan. METHOD: We used the Diagnostic Procedure Combination database to identify patients with KD treated with IVIG from April 2012 to March 2020. We identified those receiving high- and low-concentration IVIG preparations as an initial treatment. The outcomes included the proportions of patients with coronary artery abnormalities (CAAs) and IVIG resistance, length of stay, and medical costs. Propensity score-matched analyses were conducted to compare the outcomes between the 2 groups. Instrumental variable analyses were performed to confirm the results. RESULT: We identified 48 046 patients with KD and created 4:1 propensity score-matched pairs between the low- and high-concentration IVIG groups. There was a significant difference in the percentage with IVIG resistance between the 2 groups (20.6% vs 24.1%; risk difference, 3.5% [95% confidence interval, 2.3-4.7]; P < .001). However, there was no significant difference in CAAs (1.6% vs 1.6%; risk difference, 0.013% [95% confidence interval, -0.34 to 0.37]; P = .953). The instrumental variable analyses showed similar results. CONCLUSIONS: The proportion of CAAs did not differ significantly between those receiving low- and high-concentration IVIG. To confirm the results of this study, prospective studies adjusting for duration of IVIG administration and duration of observation are needed.

Hypertrophic cardiomyopathy (HCM) is genetically heterogeneous. Different variants associated with HCM have been identified in several cardiac sarcomeric protein genes. We identified the heterozygous missense variant c.2191 C>A p. Pro 731 Thr in the MYH7 gene and the heterozygous frameshift variant c.1091-1092 insTGAA p.Lys364fs*in the MYH6 gene in a Japanese family. Family members with the double variants demonstrated severe phenotypes, such as sudden cardiac-related death and heart failure. These double variants were well segregated and might be responsible for the severity of cardiovascular events in affected family members. These double variants are potentially associated with specific phenotypes in HCM. Further studies are needed to analyze specific gene functions. <Learning objective: Hypertrophic cardiomyopathy (HCM) is genetically heterogeneous and is associated with different variants in sarcomeric protein genes. We identified a heterozygous missense variant in the MYH7 gene and a heterozygous frameshift variant in the MYH6 gene in a Japanese family. These double variants are potentially associated with specific phenotypes in HCM.>.

BACKGROUND: Kawasaki disease (KD) is an acute, febrile, systemic vasculitis of unknown etiology that primarily affects the coronary arteries and generally occurs at around 1 year of age. Although the diagnosis of KD is generally not difficult, it is challenging in cases of incomplete KD lacking characteristic clinical manifestations. The incidence of incomplete KD is higher in infants younger than 6 months of age. Pneumonia is an extremely rare complication of KD and can be misinterpreted as atypical pneumonia rather than KD. Herein, we report a neonate with atypical KD and severe pneumonia who required mechanical ventilation. CASE PRESENTATION: Japanese one-month-old infant had only fever and rash on admission (day 1), and he was transferred to the intensive care unit for severe pneumonia on day 2. Although pneumonia improved following intensive care, he was diagnosed with KD on day 14 because of emerging typical clinical manifestations such as fever, bulbar nonexudative conjunctival injection, desquamation of the fingers, and coronary artery aneurysm. KD symptoms improved after three doses of intravenous immunoglobulin plus cyclosporine. However, small coronary aneurysms were present at the time of discharge. In a retrospective analysis, no pathogens were detected by multiplex real-time PCR in samples collected at admission, and the serum cytokine profile demonstrated prominent elevation of IL-6 as well as elevation of neopterin, sTNF-RI, and sTNF-RII, which suggested KD. CONCLUSIONS: The patient's entire clinical course, including the severe pneumonia, was caused by KD. As in this case, neonatal KD may exhibit atypical manifestations such as severe pneumonia requiring mechanical ventilation.

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a rare congenital cardiovascular anomaly that occurs in approximately 1 in 300,000 live births. This study aimed at identifying preoperative predictors of immediate postoperative outcomes. We conducted a retrospective, cross-sectional, single-center study and reviewed echocardiographic and hemodynamic data from all patients before and after surgical repair of ALCAPA at our center from January 2004 to February 2018. In all cases, the left coronary artery arose from the main pulmonary artery or a major branch. A total of 10 patients (age 1 month to 10 years, median 3 months) underwent ALCAPA surgical repair during the study period. No patients required a left ventricular assist device (LVAD) before surgery, but 4 patients (40%) received an LVAD after the surgery. The left ventricular ejection fraction (LVEF) improved in all patients following surgery. The utility of preoperative factors associated with pre- and post-procedure LVEF was investigated. LV dimension, as well as right coronary artery (RCA) and left coronary circumflex artery (LCX) Z scores were associated with a higher LVEF in the preoperative state. Patients with larger RCA, left ascending artery (LAD), and LCX Z scores also had a shorter duration of mechanical ventilation and ICU stay following surgery. Patients with a RCA Z score < 4 required implantation of an LVAD postoperatively. ALCAPA patients with larger RCA and LCX demonstrated a higher preoperative LVEF, while those with larger RCA, LAD, and LCX had superior postoperative hemodynamics and clinical outcomes.

Kawasaki disease (KD) is an acute systemic vasculitis that most commonly causes acquired cardiac disease in children in developed countries. The most highly recommended treatment for KD is 2 g/kg intravenous immunoglobulin (IVIG). There are two types of IVIG, sodium-containing (high-Na) and sodium-trace (low-Na) preparations. However, few studies have compared the effects of these two preparations for superiority. The purpose of this study was to compare outcomes between high and low-Na IVIG preparations in KD children using a national inpatient database in Japan. We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2017. We identified those receiving high and low-Na preparations of IVIG as an initial treatment. Outcomes included proportion of coronary artery abnormalities (CAA), IVIG resistance, adverse effects, length of stay, and medical cost. Propensity score-matched analyses were conducted to compare the outcomes between the two groups. Instrumental variable analyses were performed to confirm the results. We identified 42,345 patients with KD. There were significant differences in proportions of CAA (2.8% vs. 3.2%; p = 0.031) and IVIG resistance (17% vs. 18%, p = 0.001) between the two groups. However, there were no significant differences in length of stay or medical cost. The instrumental variable analysis confirmed the same results as the propensity score analysis.Conclusion: The present study suggests that high-Na IVIG is potentially effective for reducing the proportion of CAA in KD patients. Prospective studies are warranted to confirm the effectiveness observed in this study. What is Known: • For treatments of Kawasaki Disease in acute phase, intravenous immunoglobulin have been the most recommended to reduce fever early and prevent complications of coronary artery abnormalities. There are two types of IVIG preparations, sodium-containing IVIG and sodium-trace IVIG. However, few studies have performed comparisons to determine which preparation of IVIG is superior. What is New: • The present findings suggest that high-Na IVIG is associated with reductions in the proportions of CAAs and IVIG resistance in KD patients.

BACKGROUND: Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by prominent ventricular trabeculations on cardiovascular imaging. Acquired reversible LVNC has not been reported in pediatrics without a genetic background. CASE PRESENTATION: A 9-year-old girl with a ventriculoperitoneal (VP) shunt for neonatal posthemorrhagic hydrocephalus was referred due to exacerbation of hydrocephalus caused by VP shunt dysfunction. Transthoracic echocardiography (TTE) revealed depressed left ventricular (LV) systolic function and thick prominent trabeculae in the LV, predominantly in the apex, suggesting LVNC. Following treatment with extraventricular drainage for hydrocephalus, prominent trabeculation of the LV was diminished on TTE within 3 months. Genetic testing using next-generation sequencing was performed, and no significant variants were identified. CONCLUSIONS: We revealed for the first time a pediatric case of reversible LVNC without genetic predisposition. This case report provides valuable information on the pathogenesis of acquired LVNC and suggests that detailed evaluation is required to elucidate the diagnosis of this wide spectrum of etiologic-pathogenetic disorders.

The QT variability index (QTVI), which measures the instability of myocardial repolarization, is usually calculated from a single electrocardiogram (ECG) recording and can be easily applied in children. It is well known that frequency analysis of heart rate variability (HRV) can detect autonomic balance, but it is not clear whether QTVI is correlated with autonomic tone. Therefore, we evaluated the association between QTVI and HRV to elucidate whether QTVI is correlated with autonomic nerve activity. Apparently, healthy 320 children aged 0-7 years who visited Fujita Health University Hospital for heart checkup examinations were included. The RR and QT intervals of 60 continuous heart beats were measured, and the QTVI was calculated using the formula of Berger et al. Frequency analysis of HRV, including the QTVI analysis region, was conducted for 2 min and the ratio of low-frequency (LF) components to high-frequency (HF) components (LF/HF) and HF/(LF + HF) ratio was calculated as indicators of autonomic nerve activity. Then, the correlations between QTVI and these parameters were assessed. QTVI showed a significant positive correlation with LF/HF ratio (r = 0.45, p < 0.001) and negative correlation with HF/(LF + HF) ratio (r = -0.429, p < 0.001). These correlations remained after adjustment for sex and age. QTVI, which is calculated from non-invasive ECG and can detect abnormal myocardial repolarization, is significantly correlated with frequency analysis of HRV parameters. QTVI reflects autonomic nerve balance in children.

OBJECTIVES: Development of the autonomic nervous system may play a role in myocardial repolarization lability in infants, but its relationship to repolarization abnormalities remains unclear. Thus, the aim of the present study was to evaluate the relationship between gestational age and ventricular repolarization lability using the variability ratio (VR). METHODS: Infants who underwent electrocardiography at a 1-month check-up were included (n=209; 125 males). Gestational age and the following four VR parameters at 1 month of age were compared: VR-I, SDQT/SDRR; VR-II, SDQT/rMSSD; VR-III, SDQTc/SDRR; and VR-IV, SDQTc/rMSSD; where SD, QTc, and rMSSD are standard deviation, QT interval corrected using Fridericia's formula, and root mean square difference of successive RR intervals, respectively. Twenty-eight preterm infants born at <37 weeks of gestation and 181 full-term infants were included. RESULTS: Significant correlations were observed between gestational age and VR-I, -III, and -IV (all p<0.05). All VR values were significantly higher in preterm infants compared with full-term infants (I: 0.54 vs 0.48, II: 1.15 vs 0.96, III: 0.88 vs 0.68, IV: 1.59 vs 1.39; median, all p<0.05). CONCLUSION: VR assessed at 1 month after birth was impaired in preterm infants, suggesting immaturity of their cardiac autonomic nervous system and ventricular myocardial repolarization.

BACKGROUND: Left ventricular non-compaction (LVNC) is a heritable cardiomyopathy characterized by hypertrabeculation, inter-trabecular recesses and thin compact myocardium, but the genetic basis and mechanisms remain unclear. This study identified novel LVNC-associated mutations inNOTCH-dependent genes and investigated their mutational effects.Methods and Results:High-resolution melting screening was performed in 230 individuals with LVNC, followed by whole exome and Sanger sequencing of available family members. Dimerization of bone morphogenetic protein 10 (BMP10) and its binding to BMP receptors (BMPRs) were evaluated. Cellular differentiation, proliferation and tolerance to mechanical stretch were assessed in H9C2 cardiomyoblasts, expressing wild-type (WT) or mutant BMP10 delivered by adenoviral vectors. Rare variants, p.W143*-NRG1and p.V407I-BMP10, were identified in 2 unrelated probands and their affected family members. Although dimerization of mutant V407I-BMP10 was preserved like WT-BMP10, V407I-BMP10 pulled BMPR1a and BMPR2 receptors more weakly compared with WT-BMP10. On comparative gene expression and siRNA analysis, expressed BMPR1a and BMPR2 receptors were responsive to BMP10 treatment in H9C2 cardiomyoblasts. Expression of V407I-BMP10 resulted in a significantly lower rate of proliferation in H9C2 cells compared with WT-BMP10. Cyclic stretch resulted in destruction and death of V407I-BMP10 cells. CONCLUSIONS: The W143*-NRG1and V470I-BMP10variants are associated with LVNC. Impaired BMPR-binding ability, perturbed proliferation and differentiation processes and intolerance to stretch in V407I-BMP10 mutant cardiomyoblasts may underlie myocardial non-compaction.

BACKGROUND: Left ventricular noncompaction (LVNC) is a primary cardiomyopathy with heterogeneous genetic origins. The aim of this study was to elucidate the role of sarcomere gene variants in the pathogenesis and prognosis of LVNC. METHODS AND RESULTS: We screened 82 Japanese patients (0-35 years old), with a diagnosis of LVNC, for mutations in seven genes encoding sarcomere proteins, by direct DNA sequencing. We identified variants in a significant proportion of cases (27%), which were associated with poor prognosis (p = 0.012), particularly variants in TPM1, TNNC1, and ACTC1 (p = 0.012). To elucidate the pathological role, we developed and studied human-induced pluripotent stem cells (hiPSCs) from a patient carrying a TPM1 p.Arg178His mutation, who underwent heart transplantation. These cells displayed pathological changes, with mislocalization of tropomyosin 1, causing disruption of the sarcomere structure in cardiomyocytes, and impaired calcium handling. Microarray analysis indicated that the TPM1 mutation resulted in the down-regulation of the expression of numerous genes involved in heart development, and positive regulation of cellular process, especially the calcium signaling pathway. CONCLUSIONS: Sarcomere genes are implicated as genetic triggers in the development of LVNC, regulating the expression of numerous genes involved in heart development, or modifying the severity of disease.

BACKGROUND: Left ventricular non-compaction (LVNC) is a cardiomyopathy morphologically characterized by 2-layered myocardium and numerous prominent trabeculations, and is often associated with dilated cardiomyopathy (DCM). Variants in the gene encoding tafazzin (TAZ) may change mitochondrial function and cause dysfunction of many organs, but they also contribute to the DCM phenotype in LVNC, and the clinical and echocardiographic features of children with this phenotype are poorly understood. Methods and Results: We enrolled 92 DCM phenotype LVNC patients and performed next-generation sequencing to identify the genetic etiology. Ten TAZ variants were identified in 15 male patients (16.3%) of the 92 patients, including 3 novel missense substitutions. The patients with TAZ variants had a higher frequency of early onset of disease (92.3% vs. 62.3%, P=0.0182), positive family history (73.3% vs. 20.8%, P=0.0001), and higher LV posterior wall thickness Z-score (8.55±2.60 vs. 5.81±2.56, P=0.0103) than those without TAZ variants, although the mortality of both groups was similar. CONCLUSIONS: This study provides new insight into the impact of DCM phenotype LVNC and emphasizes the clinical advantages available for LVNC patients with TAZ variants.

Kawasaki Disease (KD) is an acute inflammatory disease that takes the form of systemic vasculitis. Endothelial microparticles (EMPs) have been recognized as an important transcellular delivery system. We hypothesized whether EMPs are involved in vasculitis in acute KD. Fifty patients with acute KD were enrolled, divided into two subgroups: those with coronary artery lesions (CAL) (n = 5) and those without CAL (NCAL) (n = 45). EMPs were measured using flow cytometry, and microRNA (miR) expression profiling was performed by microRNA array. The percentage of EMPs in acute KD was significantly higher than in controls (P < 0.0001). EMPs in patients with CAL rapidly increased after the initial treatment, and was significantly higher than those in NCAL (P < 0.001). In patients with CAL, we identified 2 specific miRs encapsulated in EMPs, hsa-miR-145-5p and hsa-miR-320a, which are predicted to affect monocyte function using in silico analysis, and were demonstrated to upregulate inflammatory cytokine mRNAs in THP-1 monocytes. In situ hybridization confirmed that hsa-miR-145-5p was preferentially expressed in CAL. EMPs may serve as a sensitive marker for the severity of vasculitis in acute KD. Moreover, these 2 specific miRs encapsulated in EMPs might be involved in inflammatory cytokine regulation and the pathogenesis of vasculitis in acute KD.

BACKGROUND: Kawasaki disease (KD) is the most common systemic vasculitis syndrome primarily affecting medium-sized arteries, particularly the coronary arteries. Though KD may be associated with immunological problems, the involvement of microRNAs (miRs) has not been fully described. METHODS: We enrolled 23 KD patients and 12 controls. We performed miR and mRNA microarray analysis of peripheral blood mononuclear cells (PBMCs) isolated from acute KD patients and controls. Continuously, we measured specific miRs, mRNA and the expression of proteins by using reverse-transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). RESULTS: We identified strikingly high levels of miR-182 and miR-296-5p during the acute febrile phase, and of miR-93, miR-145-5p, miR-145-3p, and miR-150-3p in the defervescence stage, especially in refractory KD patients. The expression of vascular endothelial growth factor A (VEGFA) mRNA, previously reported to be controlled by miR-93, was significantly elevated during the febrile phase and normalized upon treatment, negatively correlating with the expression of miR-93. Further, plasma levels of VEGF-A correlated with PBMC VEGFA mRNA expression. CONCLUSION: Several miRs are highly specific to the acute phase of KD, and may participate in regulating the expression of genes in pathways associated with KD. In particular, miR-93 may participate in regulating expression of VEGF-A and contribute to the pathogenesis of arteritis in acute KD.

The aim of our study was to evaluate the efficacy of infliximab for the treatment of patients with refractory Kawasaki disease (KD) and investigate the dynamic changes of cytokines during infliximab treatment. We have performed a study of cytokine and proinflammatory molecule levels in 43 KD patients including 18 responders to IVIG, 14 nonresponders, and 11 patients treated with infliximab. We determined serum levels of soluble TNF receptor I (sTNFR I) and IL-6, as well as VEGF, damage associated molecular pattern (DAMP) molecules; myeloid-related protein (MRP)8/MRP14 and S100A12 sequentially. In eight patients, fever subsided immediately upon infliximab treatment. Four patients, who started infliximab after 12 d of illness, developed coronary artery lesions. Each of the cytokines was elevated before infliximab treatment in all patients. Although serum levels of proinflammatory cytokines decreased dramatically after infliximab treatment, DAMP molecules and VEGF and markers of local tissue damage were not suppressed. In contrast, in IVIG responders all cytokines decreased markedly after IVIG treatment. We show that infliximab is one of the adoptive therapies in refractory KD patients. Different behaviors of proinflammatory cytokines and DAMP molecules and VEGF after infliximab treatment suggest that infliximab is effective for suppression of cytokine-mediated inflammation, but could not completely block local vasculitis.

OBJECTIVE: Receptor for advanced glycation end products (RAGE) serves as a pattern recognition receptor for several endogenous ligands that are potent inducers of inflammation. By activating endothelial cells and leukocytes, RAGE augments recruitment of leukocytes to sites of inflammation, which is a key process, especially in vasculitis. Soluble RAGE (sRAGE) acts as a naturally occurring inhibitor of RAGE by neutralizing proinflammatory ligands, e.g., S100A12. This neutrophil-derived protein has been reported to be associated with Kawasaki disease (KD) and to provoke proinflammatory responses. The aim of this study was to investigate circulating sRAGE in an acute inflammatory disorder and to compare these data directly with concentrations of the proinflammatory RAGE ligand S100A12. METHODS: Serum concentrations of sRAGE and S100A12 were analyzed by specific enzyme-linked immunosorbent assays in 50 children with KD, and additionally in 39 patients with juvenile idiopathic arthritis (JIA). In 28 of the patients with KD, levels were analyzed longitudinally over the course of the disease. RESULTS: Patients with KD and those with systemic-onset JIA had decreased levels of sRAGE during active disease, especially those patients with KD who were more severely affected and not responding to treatment. In addition, the level of sRAGE correlated negatively with the level of proinflammatory S100A12. After intravenous immunoglobulin (IVIG) therapy in patients with KD, the S100A12:sRAGE ratio was significantly different between responders and nonresponders. CONCLUSION: Inverse regulation of both sRAGE and its proinflammatory ligand S100A12 seems to be a relevant molecular mechanism promoting systemic inflammation. Calculating the S100A12:sRAGE ratio might help to detect patients with KD who are at risk of being unresponsive to IVIG therapy.