Takeshi Kusuda

Kawasaki Disease-Specific Molecules in the Sera Are Linked to Microbe-Associated Molecular Patterns in the Biofilms

Background Kawasaki disease (KD) is a systemic vasculitis of unknown etiology. The innate immune system is involved in its pathophysiology at the acute phase. We have recently established a novel murine model of KD coronary arteritis by oral administration of a synthetic microbe-associated molecular pattern (MAMP). On the hypothesis that specific MAMPs exist in KD sera, we have searched them to identify KD-specific molecules and to assess the pathogenesis. Methods We performed liquid chromatography-mass spectrometry (LC-MS) analysis of fractionated serum samples from 117 patients with KD and 106 controls. Microbiological and LC-MS evaluation of biofilm samples were also performed. Results KD samples elicited proinflammatory cytokine responses from human coronary artery endothelial cells (HCAECs). By LC-MS analysis of KD serum samples collected at 3 different periods, we detected a variety of KD-specific molecules in the lipophilic fractions that showed distinct m/z and MS/MS fragmentation patterns in each cluster. Serum KD-specific molecules showed m/z and MS/MS fragmentation patterns almost identical to those of MAMPs obtained from the biofilms formed in vitro (common MAMPs from Bacillus cereus, Yersinia pseudotuberculosis and Staphylococcus aureus) at the 1st study period, and from the biofilms formed in vivo (common MAMPs from Bacillus cereus, Bacillus subtilis/Bacillus cereus/Yersinia pseudotuberculosis and Staphylococcus aureus) at the 2nd and 3rd periods. The biofilm extracts from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus aureus also induced proinflammatory cytokines by HCAECs. By the experiments with IgG affinity chromatography, some of these serum KD-specific molecules bound to IgG. Conclusions We herein conclude that serum KD-specific molecules were mostly derived from biofilms and possessed molecular structures common to MAMPs from Bacillus cereus, Bacillus subtilis, Yersinia pseudotuberculosis and Staphylococcus aureus. Discovery of these KD-specific molecules might offer novel insight into the diagnosis and management of KD as well as its pathogenesis.

Serum neutrophil gelatinase-associated lipocalin as a predictor of the development of bronchopulmonary dysplasia in preterm infants.

BACKGROUND Bronchopulmonary dysplasia (BPD) is a chronic lung disease mostly occurring in preterm infants. The pathogenesis of BPD involves early inflammation and remodeling of the premature lung. AIM To search for the novel predictive marker of BPD development, we studied serum levels of neutrophil gelatinase-associated lipocalin (NGAL), an innate immune mediator, in preterm infants. METHODS Serum NGAL concentrations at birth were measured by enzyme-linked immunosorbent assay. The reference levels were determined in 52 infants having no anomalies or inherited diseases. The levels and clinical variables were assessed in association with BPD. RESULTS Geometric means (95%CI) of serum NGAL levels at birth of infants having no underlying diseases were 32.4 (22.1-47.5), 58.6 (47.9-71.8), and 126.2 (99.0-168.7) ng/mL for <31, 31-36 and >36 gestational weeks (GW), respectively (p<0.001). These levels positively correlated with neutrophil (p<0.0001) or monocyte counts (p<0.0001). The median NGAL levels (307.8 ng/mL) and neutrophil counts (4141/μL) at birth of 16 preterm infants (<31 GW) who developed BPD were higher than those (42.9 ng/mL and 1357/μL) of 20 infants (<31 GW) who did not (p<0.0001 and p=0.012), respectively. In multivariable analysis for 36 infants born less than 31 GW, higher NGAL levels (≥ 82 ng/mL) but not neutrophil counts at birth had a significant association with developing BPD (gestational-age adjusted odds ratio [OR]=37.45 [3.08-455.49], p<0.01). CONCLUSIONS High serum levels of NGAL at birth could be an early sensitive marker for BPD in preterm infants, because their levels were physiologically low.

Age-specific onset and distribution of the natural anticoagulant deficiency in pediatric thromboembolism

Background:The early diagnosis of inherited thrombophilia in children is challenging because of the rarity and hemostatic maturation.Methods:We explored protein C (PC), protein S (PS), and antithrombin (AT) deficiencies in 306 thromboembolic patients aged ≤20 y using the screening of plasma activity and genetic analysis.Results:Reduced activities were determined in 122 patients (40%). Low PC patients were most frequently found in the lowest age group (0–2 y, 45%), while low PS or low AT patients were found in the highest age group (16–20 y; PS: 30% and AT: 20%). Genetic study was completed in 62 patients having no other causes of thromboembolism. Mutations were determined in 18 patients (8 PC, 8 PS, and 2 AT genes). Six of eight patients with PC gene mutation were found in age 0–2 y (75%), while six of eight patients with PS gene mutation were in 7–20 y. Two AT gene–mutated patients were older than 4 y. Four PC-deficient and two PS-deficient patients carried compound heterozygous mutations. All but one PC gene–mutated patient suffered from intracranial thromboembolism, while PS/AT gene–mutated patients mostly developed extracranial venous thromboembolism.Conclusion:Stroke in low PC infants and deep vein thrombosis in low PS/AT school age children could be targeted for genetic screening of pediatric thrombophilias.

Tracheal aspirate gene expression in preterm newborns and development of bronchopulmonary dysplasia.

Background:  Bronchopulmonary dysplasia (BPD) occurs in association with prenatal conditions predisposing infants to inflammation and remodeling of the premature lungs. Because of the lack of useful biomarkers for BPD, the gene expression of tracheal aspirate fluid (TAF) cells in premature infants was analyzed.

Genetic variation of vascular endothelial growth factor pathway does not correlate with the severity of retinopathy of prematurity.

Objective:The aim of this study was to assess the genetic effects of the vascular endothelial growth factor (VEGF) pathway on retinopathy of prematurity (ROP).Study Design:A prospective study from a tertiary center that enrolled 204 Japanese infants (<35 weeks of gestational age (GA)) having no anomalies. ROP developed in 127, but not in 77 infants. The relative severity was defined as non-severe, moderate and severe ROP for GA, based on the staging criteria. VEGF (g.−634G>C, g.+13553C>T) and VEGF-receptor (KDR g.+4422(AC)11 to 14, Flt-1 c.+6724(TG)13 to 23) gene polymorphisms and clinical variables were assessed by uni/multivariate analyses.Result:The frequency of polymorphisms did not differ between ROP and non-ROP patients. The TT genotype of g.+13553 showed a higher odds ratio for non-severe ROP than CC genotype (P=0.006). Multivariate analyses indicated that low birth weight, blood transfusion and respiratory distress syndrome, but not polymorphisms, were the risk factors of advanced ROP (⩾stage 3).Conclusion:A genotype of the VEGF pathway weakly affects the severity of ROP compared with other clinical factors.

Blood Reference Intervals for Preterm Low-Birth-Weight Infants: A Multicenter Cohort Study in Japan

Preterm low-birth-weight infants remain difficult to manage based on adequate laboratory tests. The aim of this study was to establish blood reference intervals (RIs) in those newborns who were admitted to and survived in the neonatal intensive care unit (NICU). A multicenter prospective study was conducted among all infants admitted to 11 affiliated NICUs from 2010 to 2013. The clinical information and laboratory data were registered in a network database designed for this study. The RIs for 26 items were derived using the parametric method after applying the latent abnormal values exclusion method. The influence of birth weight (BW) and gestational age (GA) on the test results was expressed in terms of the standard deviation ratio (SDR), as SDRBW and SDRGA, respectively. A total of 3189 infants were admitted during the study period; 246 were excluded due to a lack of blood sampling data, and 234 were excluded for chromosomal abnormalities (n = 108), congenital anomalies requiring treatment with surgical procedures (n = 76), and death or transfer to another hospital (n = 50). As a result, 2709 infants were enrolled in this study. Both the SDRGA and SDRBW were above 0.4 in the test results for total protein (TP), albumin (ALB), alanine aminotransferase (ALT), and red blood cells (RBC); their values increased in proportion to the BW and GA. We derived 26 blood RIs for infants who were admitted to NICUs. These RIs should help in the performance of proper clinical assessments and research in the field of perinatal-neonatal medicine.

Relieving pain and distress during venipuncture: Pilot study of the Japan Environment and Children's Study (JECS)

Pain management for needle‐related procedures is poor in Japan. In many countries the use of lidocaine/prilocaine cream for the relief of pain associated with venipuncture has been approved. In children, a psychological approach has also been shown to be effective in reducing pain with venipuncture. We developed a multidisciplinary procedure that combines a cream (2.5% lidocaine and 2.5% prilocaine) and pharmacological approaches such as preparation, education, positioning and distraction. We evaluated the feasibility and acceptability of the procedure for young children. Among 132 pediatric participants, 58.3% did not cry during venipuncture. According to caregiver questionnaire, 71.9% felt that the multidisciplinary procedure eliminated the fear of needle‐related procedures in the children; 90.9% were satisfied with it and 75.8% thought it should be applied to all children undergoing venipuncture. The present results suggest that the multidisciplinary procedure is feasible, acceptable and suitable for use in children undergoing venipuncture.

Distinct Distribution of Immunocytes in a Retropharyngeal Lymphadenopathy Associated with Kawasaki Disease: A Case Study Compared with Tonsillitis

Objectives: Retropharyngeal lesions are often associated with Kawasaki disease (KD). A 4-year-old male first presented a peritonsillar and retropharyngeal abscess-like lesion. Surgical tonsillectomy was performed to avoid a risk of mediastinal abscess, but he fulfilled the diagnostic criteria of KD after the operation. This prompted us to perform a histological study on the KD tonsils. Methods: The histopathology of the KD tonsil specimens were compared with hypertrophic tonsils obtained from 4 patients with chronic tonsillitis unrelated to KD assessed by the immunostainings. Results: KD tonsils showed small lymphatic follicles and neutrophil infiltration in the peritonsillar muscle layer, with no evidence of vasculitis or abscess formation. The KD tonsils exclusively showed (1) predominant activated CD4+ T cells in the perifollicular interstitium, (2) sparse scattering of CD68+ monocytes/macrophages in the lymphatic follicles, and (3) polyclonal carcinoembryonic antigen-positive cells in the lymphatic follicles and venules with the high endothelial cells. Conclusions: The uniquely distributed immunocytes suggest the inflammatory process of KD involving the pathogen-associated molecules.

Transient Hemi-Lower Limb Ischemia in the Newborn: Arterial Thrombosis or Persistent Sciatic Artery?

Neonatal thromboembolism occurs with various predispositions and triggers. Early diagnosis of the thrombosis is challenging and essential for the therapeutic interventions. We herein report two newborns who presented with transient hemi-lower limb ischemia due to (1) arterial thrombosis or (2) a persistent sciatic artery (PSA). The patient with arterial thrombosis showed elevations of fibrin degradation product and D-dimer and received antithrombin and heparin intravenously. The patient with PSA was immediately assessed by a contrast-enhanced computed tomography because of a transient ischemic episode with no evidence of hypercoagulability. Newborns suspected of having arterial thrombosis may need urgent surgical intervention along with thrombolytic and anticoagulant therapy to prevent organ ischemia and amputation of extremities. Conversely, some PSA cases have reportedly been treated conservatively. This vascular anomaly was previously reported as a cause of lower limb ischemia only in a newborn. PSA is a critical differential diagnosis of neonatal arterial thrombosis that needs urgent therapeutic intervention.