Regulation of oxidative stress in patients with Kawasaki disease.

Although there is ample evidence that Kawasaki disease (KD) is associated with vascular inflammation, few studies have addressed the influence of oxidative stress. The goal of this study was to determine whether oxidative stress contributes to inflammation during KD, and also whether corticosteroid therapy can reduce oxidative stress. Serum reduced glutathione (sGSH) and serum thioredoxin (sTRX) were measured during KD to evaluate the phase-dependent change in the redox state in KD. Additionally, the efficacy of the therapies to reduce oxidative stress was assessed. The sGSH level significantly decreased post-intravenous immunoglobulin (IVIG). The sGSH level significantly increased during the convalescent phase. The sTRX level was significantly lower during the convalescent phase than that during the pre- and the post-IVIG. There was no difference in the sGSH and sTRX changes between the IVIG therapy and the IVIG + prednisolone (PSL) therapy, except for the convalescent phase in sTRX. Systemic inflammation in KD induces changes in the redox state, whereas the IVIG + PSL therapy did not show any remarkable change on oxidative stress in comparison to the IVIG therapy. Therapeutic intervention against oxidative stress might therefore be beneficial as adjunctive therapies for KD.

Recognition of fungal protease activities induces cellular activation and eosinophil-derived neurotoxin release in human eosinophils.

Eosinophils are multifunctional leukocytes implicated in the pathogenesis of asthma and in immunity to certain organisms. Associations between exposure to an environmental fungus, such as Alternaria, and asthma have been recognized clinically. Protease-activated receptors (PARs) are G protein-coupled receptors that are cleaved and activated by serine proteases, but their roles in innate immunity remain unknown. We previously found that human eosinophils respond vigorously to Alternaria organisms and to the secretory product(s) of Alternaria with eosinophils releasing their proinflammatory mediators. In this study, we investigated the roles of protease(s) produced by Alternaria and of PARs expressed on eosinophils in their immune responses against fungal organisms. We found that Alternaria alternata produces aspartate protease(s) and that human peripheral blood eosinophils degranulate in response to the cell-free extract of A. alternata. Eosinophils showed an increased intracellular calcium concentration in response to Alternaria that was desensitized by peptide and protease ligands for PAR-2 and inhibited by a PAR-2 antagonistic peptide. Alternaria-derived aspartate protease(s) cleaved PAR-2 to expose neo-ligands; these neo-ligands activated eosinophil degranulation in the absence of proteases. Finally, treatment of Alternaria extract with aspartate protease inhibitors, which are conventionally used for HIV-1 and other microbes, attenuated the eosinophils' responses to Alternaria. Thus, fungal aspartate protease and eosinophil PAR-2 appear critical for the eosinophils' innate immune response to certain fungi, suggesting a novel mechanism for pathologic inflammation in asthma and for host-pathogen interaction.

Risk stratification in the decision to include prednisolone with intravenous immunoglobulin in primary therapy of Kawasaki disease.

BACKGROUND: We reported previously that intravenous immunoglobulin (IVIG) plus prednisolone for initial therapy for Kawasaki disease (KD) prevented coronary artery abnormalities (CAA) more effectively than IVIG alone. However, questions remain as to whether PSL has potential benefit in all KD patients. The present study was designed to explore the possibility of stratified initial therapy including PSL in patients with and without a high predicted risk of being an IVIG nonresponder. METHODS: We retrospectively analyzed data from KD patients who received IVIG (n = 896) or IVIG + PSL (n = 110) by scoring the likely risk of being an IVIG nonresponder. We compared clinical and coronary outcomes between treatment-defined groups separately for high- and low-risk patients. RESULTS: Among low-risk patients (score 0-4), clinical and coronary outcomes were similar. Among high-risk patients (score 5 or more), incidences of treatment failure and coronary artery abnormalities until 1-month follow-up were more frequent in the IVIG than in the IVIG + PSL group. Sex- and score point-adjusted odds ratios for IVIG + PSL were 0.17 (95% confidence interval, 0.08-0.39) for treatment failure and 0.27 (95% confidence interval, 0.07-0.85) for coronary artery abnormalities A among high-risk patients. CONCLUSIONS: IVIG + PSL treatment was associated with improving clinical and coronary outcomes in patients at high risk of being IVIG nonresponders.

Left displacement of the mediastinum determines the imbalance in the pulmonary vascular bed and lung volume in children with pectus excavatum.

The purpose of this study was to determine the influence of morphologic alteration on lung function in children with pectus excavatum (PE) and to establish the usefulness of chest radiography to predict the imbalance of pulmonary perfusion and lung volume. Chest radiography, pulmonary perfusion scintigraphy, and computed tomography (CT) for calculation of each lung volume were performed in 38 children with PE. To assess the relationship between position change of the mediastinum and lung, the following indices were calculated: (1) vertebral index (VI); the severity of sternal depression on the lateral chest radiograph, (2) left displacement index (LDI); the ratio between the left border of the mediastinum and the left border of the thorax to the transverse thoracic dimension on posterioanterior chest radiography; (3) left-to-right count ratio for the lung scintigraphy (Ls/Rs), and (4) the left-to-right thorax volume ratio from the CT scan (Lv/Rv). Compared to children without PE, VI was significantly higher, and LDI was lower in patients with PE. Pulmonary perfusion scintigraphy and CT showed that left pulmonary perfusion and lung volume were significantly lower than in the right lung in PE. LDI showed a close correlation with Ls/Rs (R = 0.443, P = 0.005) and Lv/Rv (R = 0.703, P < 0.001). Left displacement of the mediastinum within the closed thoracic cavity directly imposes constraints on the left lung, resulting in reductions of perfusion and lung volume that likely determine the physiologic severity of lung function in PE. Posterioanterior chest radiography might be useful in predicting the severity of PE.

[Risk stratification and prediction of resistance to intravenous immunoglobulin in Kawasaki disease].

Intravenous immunoglobulin is effective to resolve inflammation of Kawasaki disease and reduce the incidence of coronary artery abnormalities. However approximately 20% of patients with Kawasaki disease had persistent or recurrent fevers after intravenous immunoglobulin and are considered to have a high risk for coronary artery abnormalities. Recently, we developed a new risk score that resistance to intravenous immunoglobulin could be identified with high sensitivity and specificity in advance using seven laboratory and demographic variables available before initiation of primary therapy. In this article, we will review prediction of intravenous immunoglobulin unresponsiveness. In addition, we will focus on the risk stratification of primary therapy using the risk score.

A multicenter prospective randomized trial of corticosteroids in primary therapy for Kawasaki disease: clinical course and coronary artery outcome.

OBJECTIVE: To investigate the role of corticosteroids in the initial treatment of Kawasaki disease (KD). STUDY DESIGN: Between September 2000 and March 2005, we randomly assigned 178 KD patients from 12 hospitals to either an intravenous immunoglobulin (IVIG) group (n = 88; 1 g/kg for 2 consecutive days) or an IVIG plus corticosteroid (IVIG+PSL) group (n = 90). The primary endpoint was coronary artery abnormality (CAA) before a 1-month echocardiographic assessment. Secondary endpoints included duration of fever, time to normalization of serum C-reactive protein (CRP), and initial treatment failure requiring additional therapy. Analyses were based on intention to treat. RESULTS: Baseline characteristics of groups were similar. Fewer IVIG+PSL patients than IVIG patients had a CAA before 1 month (2.2% vs 11.4%; P = .017). The duration of fever was shorter (P < .001) and CRP decreased more rapidly in the IVIG+PSL group than in the IVIG group (P = .001). Moreover, initial treatment failure was less frequent (5.6% vs 18.2%; P = .010) in the IVIG+PSL group. All patients assigned to the IVIG+PSL group completed treatment without major side effects. CONCLUSIONS: A combination of corticosteroids and IVIG improved clinical course and coronary artery outcome without causing untoward effects in children with acute KD.

Prediction of intravenous immunoglobulin unresponsiveness in patients with Kawasaki disease.

BACKGROUND: In the present study, we developed models to predict unresponsiveness to intravenous immunoglobulin (IVIG) in Kawasaki disease (KD). METHODS AND RESULTS: We reviewed clinical records of 546 consecutive KD patients (development dataset) and 204 subsequent KD patients (validation dataset). All received IVIG for treatment of KD. IVIG nonresponders were defined by fever persisting beyond 24 hours or recrudescent fever associated with KD symptoms after an afebrile period. A 7-variable logistic model was constructed, including day of illness at initial treatment, age in months, percentage of white blood cells representing neutrophils, platelet count, and serum aspartate aminotransferase, sodium, and C-reactive protein, which generated an area under the receiver-operating-characteristics curve of 0.84 and 0.90 for the development and validation datasets, respectively. Using both datasets, the 7 variables were used to generate a simple scoring model that gave an area under the receiver-operating-characteristics curve of 0.85. For a cutoff of 0.15 or more in the logistic regression model and 4 points or more in the simple scoring model, sensitivity and specificity were 86% and 67% in the logistic model and 86% and 68% in the simple scoring model. The kappa statistic is 0.67, indicating good agreement between the logistic and simple scoring models. CONCLUSIONS: Our predictive models showed high sensitivity and specificity in identifying IVIG nonresponders among KD patients.

Nonpathogenic, environmental fungi induce activation and degranulation of human eosinophils.

Eosinophils and their products are probably important in the pathophysiology of allergic diseases, such as bronchial asthma, and in host immunity to certain organisms. An association between environmental fungal exposure and asthma has been long recognized clinically. Although products of microorganisms (e.g., lipopolysaccharides) directly activate certain inflammatory cells (e.g., macrophages), the mechanism(s) that triggers eosinophil degranulation is unknown. In this study we investigated whether human eosinophils have an innate immune response to certain fungal organisms. We incubated human eosinophils with extracts from seven environmental airborne fungi (Alternaria alternata, Aspergillus versicolor, Bipolaris sorokiniana, Candida albicans, Cladosporium herbarum, Curvularia spicifera, and Penicillium notatum). Alternaria and Penicillium induced calcium-dependent exocytosis (e.g., eosinophil-derived neurotoxin release) in eosinophils from normal individuals. Alternaria also strongly induced other activation events in eosinophils, including increases in intracellular calcium concentration, cell surface expression of CD63 and CD11b, and production of IL-8. Other fungi did not induce eosinophil degranulation, and Alternaria did not induce neutrophil activation, suggesting specificity for fungal species and cell type. The Alternaria-induced eosinophil degranulation was pertussis toxin sensitive and desensitized by preincubating cells with G protein-coupled receptor agonists, platelet-activating factor, or FMLP. The eosinophil-stimulating activity in Alternaria extract was highly heat labile and had an M(r) of approximately 60 kDa. Thus, eosinophils, but not neutrophils, possess G protein-dependent cellular activation machinery that directly responds to an Alternaria protein product(s). This innate response by eosinophils to certain environmental fungi may be important in host defense and in the exacerbation of inflammation in asthma and allergic diseases.

Serum procalcitonin concentration in patients with Kawasaki disease.

BACKGROUND: Procalcitonin (PCT) is a new parameter of inflammation, the clinical usefulness of which is currently being evaluated. MATERIALS AND METHODS: We determined simultaneously the serum concentrations of PCT and C-reactive protein (CRP) as well as the white blood cell (WBC) count in 25 patients with Kawasaki disease (KD), 17 with bacterial infections, 10 with systemic autoimmune diseases, 17 with viral infections and 18 healthy children. The optimal cut-off value of each parameter for predicting coronary aneurysms was determined using receiver operating characteristic curves. RESULTS: Significantly higher serum concentrations of PCT were observed in patients with KD (2.3 +/- 3.0 ng/ml) and bacterial infections (2.2 +/- 2.9 ng/ml) than in patients with autoimmune diseases (0.4 +/- 0.4 ng/ml) or viral infections (0.4 +/- 0.3 ng/ml), or in healthy children (0.2 +/- 0.1 ng/ml). The serum PCT but not the WBC count or CRP, differentiated the KD patients from the patients with autoimmune diseases. The optimal cut-off value of 3.0 ng/ml of PCT increased the prediction rate of coronary aneurysms that subsequently occurred in 4 (16%) patients with KD. CONCLUSIONS: The serum PCT may be clinically useful for determining the severity of KD and for narrowing the differential diagnosis of patients with inflammatory diseases.

Effect of corticosteroids in addition to intravenous gamma globulin therapy on serum cytokine levels in the acute phase of Kawasaki disease in children.

OBJECTIVE: The aim of this multicenter prospective and randomized study was to determine the effect of adding corticosteroids to intravenous gamma globulin (i.v.GG) therapy on serum cytokine levels, as well as to see its effect on the clinical course in children in the acute phase of Kawasaki disease (KD). STUDY DESIGN: Patients with KD (n=32) were randomized to receive either i.v.GG alone (G group) or i.v.GG plus corticosteroids (G+S group). The clinical course and cytokine responses between groups were compared. RESULTS: The pretreatment serum levels of interleukin (IL)-2, IL-6, IL-8, and IL-10 were significantly higher in patients with KD than in healthy controls. Although i.v.GG alone failed to reduce cytokine concentrations within 24 hours of i.v.GG administration, corticosteroids plus i.v.GG reduced IL-2, IL-6, IL-8, and IL-10 levels. The levels of IL-2, IL-6, IL-8, and IL-10 within 24 hours after initiating i.v.GG therapy were significantly lower in the G+S group than in the G group. The duration of fever was shorter, and the C-reactive protein concentration decreased more quickly in the G+S group than in the G group. CONCLUSIONS: These findings suggest that corticosteroids rapidly ameliorate symptoms by reducing cytokine levels in children with KD.

Effects of STA(2), a thromboxane A(2) mimetic, in inducing airflow obstruction and airway microvascular leakage in guinea pigs.

BACKGROUND: U-46619, a thromboxane A(2) (TXA(2)) mimetic, is shown to cause airway microvascular leakage, although the effects is weak when comparing with that to induce bronchoconstriction in guinea pigs. OBJECTIVE: In order to know the airway effect of TXA(2) more accurately, we have examined the effects of STA(2), a TXA(2) mimetic with higher affinity to TXA(2) (TP) receptors than U-46619, to induce airway microvascular leakage and airflow obstruction. METHODS: Anesthetized and ventilated guinea pigs were i.v. given STA(2) (3-30 nmol/kg) or U-46619 (3-100 nmol/kg) 1 min after i.v. Evans blue dye. STA(2)- and U-46619-induced increases in lung resistance (R(L)) was measured for 6 min. The amount of extravasated Evans blue dye in the lower airways was, then, examined as an index of leakage. In selected animals, specific TP receptor antagonists (10 microg/kg S-1452 or 10 mg/kg ONO-3708) were pretreated i.v. RESULTS: Both STA(2) and U-46619 induced significant increases in leakage and airflow obstruction. However, STA(2) induced a slow and significantly less increase in R(L) but caused a significantly greater increase in extravasation of Evans blue dye compared to U-46619. Specific TP receptor antagonists completely abolished both airway effects induced by STA(2) and U-46619. CONCLUSION: Our present results have supported a possibility that TXA(2) induces microvascular leakage as well as bronchoconstriction in the airways.