Seigo Okada

High mobility group box 1 in patients with 2009 pandemic H1N1 influenza-associated encephalopathy.

BACKGROUND Patients with 2009 pandemic H1N1 influenza-associated encephalopathy (pIE) have been reported in Japan. The most common clinical symptoms of this condition are seizures and progressive coma with high-grade fever. We previously highlighted the cytokine profile of pIE; our results suggest that proinflammatory cytokines play an important role in the pathogenesis. High mobility group box 1 (HMGB1) protein is a late mediator of inflammation or sepsis. However, there are few reports regarding the serum and cerebrospinal fluid (CSF) levels of HMGB1 in pIE patients. METHODS We measured serum and CSF levels of HMGB1 in the following: pIE patients with poor outcomes, pIE patients without neurological sequelae, influenza patients without pIE, and control subjects. RESULTS Serum HMGB1 levels were significantly higher in pIE patients with poor outcomes compared to those without neurological sequelae. In contrast, there was no difference in CSF HMGB1 levels among all groups. Regarding pIE patients, we found a significant positive correlation between HMGB1 levels and IL-6 in the serum but not in the CSF. CONCLUSIONS Our results suggest that HMGB1 protein may be involved in the pathogenesis of pIE and that a high serum, but not CSF, level of inflammatory cytokines plays an important role in the severity of pIE.

Analysis of bronchoalveolar lavage fluid in a mouse model of bronchial asthma and H1N1 2009 infection

BACKGROUND Bronchial asthma is known as a risk factor of admission to the intensive care unit. However, the mechanism by which pandemic 2009 H1N1 (A(H1N1)pdm09) infection increases the severity of symptoms in patients with bronchial asthma is unknown; therefore, we aimed at determining this mechanism. METHODS Inflammatory cell levels in the bronchoalveolar lavage (BAL) fluid from the non-asthma/mock, non-asthma/A(H1N1)pdm09, asthma/mock, and asthma/A(H1N1)pdm09 groups were determined using BALB/c mice. Cell infiltration levels, cytokine levels, and viral titers were compared among the groups. RESULTS Neutrophil, monocyte, interleukin (IL)-5, IL-6, IL-10, IL-13, and tumor necrosis factor (TNF)-α levels were significantly higher in the BAL fluid from the non-asthma/A(H1N1)pdm09 and asthma/A(H1N1)pdm09 groups than in the mock groups (p<0.05 for neutrophils and monocytes; p<0.01 for the rest). The number of eosinophils and CD8(+) lymphocytes and the level of transforming growth factor beta 1 (TGF-β1) in BAL fluid in the asthma/A(H1N1)pdm09 group were significantly higher among all groups (p<0.05 for eosinophils and CD8(+) lymphocytes; p<0.01 for TGF-β1). The levels of IL-6, IL-10, IL-13, and TNF-α were significantly higher in the asthma/A(H1N1)pdm09 group than in the non-asthma/A(H1N1)pdm09 group (p<0.05 for IL-6 and IL-10; p<0.01 for IL-13 and TNF-α). The level of IFN-γ in the asthma/A(H1N1)pdm09 group was significantly lower than that in the non-asthma/A(H1N1)pdm09 group (p<0.05). The viral titers in the BAL fluids were higher in the asthma/A(H1N1)pdm09 group than in the non-asthma/A(H1N1)pdm09 group (p<0.05). Histopathological examination showed more severe infiltration of inflammatory cells and destruction of lung tissue in the asthma/A(H1N1)pdm09 group than in the non-asthma/A(H1N1)pdm09 group. CONCLUSIONS Severe pulmonary inflammation induced by elevated levels of cytokines, combined with increased viral replication due to decreased IFN-γ levels, may contribute to worsening respiratory symptoms in patients with bronchial asthma and A(H1N1)pdm09 infection.

Coronary artery lesions and the increasing incidence of Kawasaki disease resistant to initial immunoglobulin

BACKGROUNDS Kawasaki disease (KD) is a systemic vasculitis of childhood involving coronary arteries. Treatment for intractable cases at a higher risk of cardiac sequelae remains controversial. METHODS Clinical outcomes of KD patients diagnosed in Yamaguchi prefecture, Japan between 2003 and 2014 were analyzed using the medical records from all 14 hospitals covering the prefecture. The study included 1487 patients (male:female, 873:614; median age at diagnosis, 24months). RESULTS The proportion of initial intravenous immunoglobulin (IVIG)-resistant patients increased from 7% to 23% during this decade, although no patients died. Twenty-four patients developed coronary artery lesions (CALs) over one month after the KD onset. The incidence of CAL in patients who received corticosteroid during the disease course (10/37; 27.0%) was higher than that in those who did not (14/1450; 0.97%, p=2.0×10(-35)). Nine patients who responded to initial IVIG plus corticosteroids had no CAL. Conversely, IVIG-resistant patients with alternate corticosteroid therapy more frequently developed CAL than those without it (10/28; 35.7% vs. 5/194; 2.6%, p=8.9×10(-10)). Multivariate analyses indicated corticosteroid therapy (p<0.0001), hyperbilirubinemia (p=0.0010), and a longer number of days before treatment (p=0.0005) as risk factors associated with CAL over a month after onset. The odds ratio of corticosteroid use increased from 18.3 to 43.5 if the cases were limited to initial IVIG non-responders and corticosteroid free-IVIG responders. CONCLUSIONS IVIG-failure has recently increased. The incidence of CAL increased in intractable cases with prolonged corticosteroid use. Corticosteroid may not be alternate choice for IVIG-failure to reduce the risk of cardiac sequelae.

Cytokine profile of bronchoalveolar lavage fluid from a mouse model of bronchial asthma during seasonal H1N1 infection.

BACKGROUND Several studies support the role of viral infections in the pathogenesis of asthma exacerbation. However, several pediatricians believe that influenza virus infection does not exacerbate bronchial asthma, except for influenza A H1N1 2009 pandemic [A(H1N1)pdm09] virus infection. We previously reported that A(H1N1)pdm09 infection possibly induces severe pulmonary inflammation or severe asthmatic attack in a mouse model of bronchial asthma and in asthmatic children. However, the ability of seasonal H1N1 influenza (H1N1) infection to exacerbate asthmatic attacks in bronchial asthma patients has not been previously reported, and the differences in the pathogenicity profiles, such as cytokine profiles, remains unclear in bronchial asthma patients after A(H1N1)pdm09 and H1N1 infections. METHODS The cytokine levels and viral titers in the bronchoalveolar lavage (BAL) fluid from mice with and without asthma after H1N1 infection (A/Yamagata and A/Puerto Rico strains) were compared. RESULTS The interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, IL-5, interferon (IFN)-α, IFN-β, and IFN-γ levels were significantly higher in the BAL fluids from the control/H1N1 mice than from the asthmatic/H1N1 mice. The viral titers in the BAL fluid were also significantly higher in the control/H1N1mice than in the asthmatic/H1N1 mice infected with either A/Yamagata or A/Puerto Rico. CONCLUSIONS A(H1N1)pdm09 infection, but not H1N1 infection, can induce severe pulmonary inflammation through elevated cytokine levels in a mouse model of asthma.

Adjunct cyclosporine therapy for refractory Kawasaki disease in a very young infant

Herein we describe the case of a 6‐week‐old boy who developed complete Kawasaki disease (KD). The cytokine profile and activation of monocytes and subsequent T cells matched the typical feature of refractory KD. The patient received a total of three courses of i.v. immunoglobulin (IVIG), but did not achieve clinical relief. Adjunctive therapy with oral cyclosporine A (CsA) led to prompt defervescence. This was continued for 7 days without serious adverse events. Coronary artery dilatations regressed within 3 months of follow up. KD infants <3 months of age are at higher risk of coronary artery aneurysm than the older ones. To our knowledge, oral CsA treatment has not been reported in such young infants with KD. The diagnosis and treatment of very young infants with KD are challenging. Adjunctive use of CsA in IVIG treatment could be effective for refractory KD in infants <3 months of age.

A novel de novo mutation of β-cardiac myosin heavy chain gene found in a twelve-year-old boy with hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM) is characterized by thickening of left ventricle (LV), especially the interventricular septum (IVS), and diastolic ventricular failure (Maron 2002). It is one of the most important diseases causing a sudden death in young individuals (Maron 2002). Approximately 50% of the patients have a family history of HCM, and exhibit an autosomal dominant (AD) pattern of inheritance (Maron et al. 2012). Most of the causative genes for familial HCM encode contractile proteins such as β-cardiac myosin heavy chain, cardiac myosin-binding protein-C, and cardiac troponin T (Kimura 2010; Maron et al. 2012; Otsuka et al. 2012). Moreover, various mutations of HCMcausing genes exhibit a variety of phenotypes and prognoses (Towbin 2000; Franz et al. 2001; Towbin and Bowles 2002; Ho and Seidman 2006; Kimura 2010; Otsuka et al. 2012). The gene for β-cardiac myosin heavy chain, MYH7, is an important causative gene for HCM. In recent studies, ∼20% of HCM patients have been shown to carry a mutation in MYH7 (Richard et al. 2003; Van Driest et al. 2004, 2005; Kimura 2010; Otsuka et al. 2012), and several types of MYH7 mutations have been reported (Kubo et al. 2011). In the present report, we describe a case of a 12-year-old boy with HCMwho is a carrier of a novel de novo point mutation in MYH7 (p.Ala820Asp). Functional analysis of this mutation indicated that it may eventually lead to impairment of protein function, and therefore, we are carefully following up this patient.

Increased Pituitary Volumes in Children after Fontan Operation: Congestion in the Other Portal Circulation

&NA; We performed brain magnetic resonance imaging in 40 patients after the Fontan procedure and 40 control subjects. Pituitary volumes in patients after Fontan were significantly larger than those in the control subjects (472 [425‐527] vs 257 [182‐311]; P < .0001), and were significantly related to central venous pressure.

Siblings with Idiopathic Left Atrial Appendage Ostial Stenosis and Cor Triatriatum.

Isolated left atrial appendage (LAA) ostial stenosis is a very rare entity found coincidentally in adults by transesophageal echocardiography. A 3‐month‐old healthy infant was suspected as having cor triatriatum. His brother had a history of surgical treatment of cor triatriatum. A cardiac catheterization revealed a narrowed ostium of the LAA and confirmed the echocardiographic diagnosis of isolated LAA ostial stenosis. This is the first pediatric case of idiopathic LAA ostial stenosis. The siblings called our attention to the differential diagnosis and the etiopathogenesis between LAA ostial stenosis and cor triatriatum.

Acute pericardial effusion representing the TNF-α-mediated severe inflammation but not the coronary artery outcome of Kawasaki disease

Objectives: To establish the optimal inflammation control of Kawasaki disease (KD), we investigated the clinical and pathophysiological basis of pericardial effusion (PE) during the acute phase of KD. Method: Clinical and laboratory features of Japanese KD children with PE (PE group: n = 9) and without PE (non-PE group: n = 89) were studied retrospectively by using the medical records. Serum levels of soluble tumour necrosis factor receptor 1 (sTNFR1), interleukin 6 (IL-6), and vascular endothelial growth factor (VEGF) were assessed by enzyme-linked immunosorbent assays (ELISAs). Results: PE group patients had coronary artery lesions (CALs) more frequently than non-PE group patients during the acute phase of KD (33% vs. 5.6%, p = 0.024). PE patients also showed lower levels of haemoglobin (p < 0.01) and serum albumin (p < 0.01) and higher platelet counts (p = 0.013) than non-PE patients. The proportion of neurological symptoms, but not other manifestations, in the PE group was higher than in the non-PE group (p = 0.022). All patients survived free from coronary artery aneurisms. Serum levels of sTNFR1, but not the other cytokines, in the PE group were higher than those in the non-PE group (p < 0.001). The sTNFR1 levels correlated positively with C-reactive protein (CRP) (r = 0.30, p = 0.019) or total bilirubin (r = 0.40, p < 0.01) levels. Conclusions: Acute PE in KD patients indicated the severity of TNF-mediated vascular inflammation and concurrent CALs. According to the progression, these patients might need more targeted therapy of anti-inflammation for a better coronary outcome.

Remission of autoimmune neutropenia after development of Kawasaki disease

We report the second case of the association of Kawasaki disease (KD) and autoimmune neutropenia (AIN). A 21‐month‐old female diagnosed as having AIN of infancy developed a complete KD when severe neutropenia continued. The patient suffered from no coronary artery leions, and well responded to a single high‐dose gamma‐globulin therapy. The cytokine profile of the neutropenic infant was representative of the typical KD. Neutrophil counts notably increased during the convalescent phase of KD, and were then normalized forthwith. The prompt resolutions of KD and AIN paralleled the increase of circulating transforming growth factor (TGF)‐β1 levels. The clinical course of the patient was contrasted to that of the first reported case of a patient who developed severe and refractory KD after the high dose granulocyte‐colony stimulating factor (G‐CSF) therapy.