Masato Takeuchi

Intussusception among Japanese children: an epidemiologic study using an administrative database

BackgroundThe epidemiology of intussusception, including its incidence, can vary between different countries. The aim of this study was to describe the epidemiology of childhood intussusception in Japan using data from a nationwide inpatient database.MethodsWe screened the database for eligible cases ≤ 18 years of age, who were coded with a discharge diagnosis of intussusception (International Classification of Diseases, 10th revision: K-561) between July to December in 2007 and 2008. We then selected cases according to Level 1 of the diagnostic certainty criteria developed by the Brighton Collaboration Intussusception Working Group. We examined the demographics, management, and outcomes of cases, and estimated the incidence of intussusception.ResultsWe identified 2,427 cases of intussusception. There were an estimated 2,000 cases of infantile intussusception annually in Japan, an incidence of 180-190 cases per 100,000 infants. The median age at diagnosis was 17 months, and two-thirds of the patients were male. Treatment with an enema was successful in 93.0% of cases (2255/2427). The remainder required surgery. Secondary cases accounted for 3.1% (76/2427). Median length of hospital stay was 3 days. Of the 2,427 cases, we found 2 fatal cases associated with intussusception.ConclusionsThis is currently the largest survey of childhood intussusception in Asia using a standardized case definition. Our results provide an estimate of the baseline risk of intussusception in Japan, and it is higher than the risk observed in other countries.

Pyloromyotomy versus i.v. atropine therapy for the treatment of infantile pyloric stenosis: Nationwide hospital discharge database analysis

Several studies have suggested that i.v. atropine has a potential role in treating infantile hypertrophic pyloric stenosis (IHPS). It remains unclear, however, whether surgery can be replaced by i.v. therapy.

Clinical features of infants hospitalized for 2009 pandemic influenza A (H1N1) in Japan: analysis using a national hospital discharge database.

Background: Earlier studies reported that infants <12 months of age were at high risk of hospitalization for 2009 pandemic influenza A H1N1 virus (2009 H1N1) infection, but there was little information about the clinical courses in these patients. Methods: A retrospective study was performed using the nationwide inpatient Diagnosis Procedure Combination Database in Japan. We searched data on hospitalizations, between July and December 2009, of infants (<12 months) and children 12 to <24 months of age with influenza. We examined their demographic data and hospitalization details, including treatment, complications, and outcomes. Results: During the study period, 1023 infants were hospitalized for influenza; 98.1% of them were previously healthy. Complications attributed to influenza were found in 181 (17.7%) infants, including 3 critical illnesses and 1 death. Oseltamivir was prescribed to 535 (53.3%) infants. We found no evidence that oseltamivir was associated with either complications or length of hospital stay. During the same period, 579 children 1 year of age were admitted for 2009 H1N1, and 56.5% of them had influenza-related complications. Conclusions: In Japan, infants with 2009 H1N1 were twice as likely to be hospitalized as children 1 year of age. However, the clinical course of the hospitalized infants was generally uncomplicated.

The incidence of pertussis hospitalizations among Japanese infants: excess hospitalizations and complications?

We examined pertussis hospitalizations among infants aged <1 year between 2006 and 2008 using the nationwide inpatient database in Japan. A total of 660 infants hospitalized for pertussis were identified. Peak incidence occurred at age 1 month and infants aged 0-2 months (too young for pertussis vaccination) and ≥3 months (eligible for at least one dose of vaccination) accounted for 44·5% and 55·5% of hospitalizations, respectively. Complications related to pertussis were found in 165 (25·0%) cases, including one death; the age at admission did not differ significantly between patients with and those without complications (mean age 4·1 vs. 4·5 months, P=0·12). Seventeen patients required mechanical ventilation. Of the 17 cases, 14 infants were aged <3 months and three infants were aged ≥3 months. Our findings highlight that the vaccination schedule against pertussis may often be delayed in Japan.

Novel Risk Assessment Tool for Immunoglobulin Resistance in Kawasaki Disease: Application Using a Random Forest Classifier

Background: Resistance to intravenous immunoglobulin (IVIG) therapy is a risk factor for coronary lesions in patients with Kawasaki disease (KD). Risk-adjusted initial therapy may improve coronary outcome in KD, but identification of high risk patients remains a challenge. This study aimed to develop a new risk assessment tool for IVIG resistance using advanced statistical techniques. Methods: Data were retrospectively collected from KD patients receiving IVIG therapy, including demographic characteristics, signs and symptoms of KD and laboratory results. A random forest (RF) classifier, a tree-based machine learning technique, was applied to these data. The correlation between each variable and risk of IVIG resistance was estimated. Results: Data were obtained from 767 patients with KD, including 170 (22.1%) who were refractory to initial IVIG therapy. The predictive tool based on the RF algorithm had an area under the receiver operating characteristic curve of 0.916, a sensitivity of 79.7% and a specificity of 87.3%. Its misclassification rate in the general patient population was estimated to be 15.5%. RF also identified markers related to IVIG resistance such as abnormal liver markers and percentage neutrophils, displaying relationships between these markers and predicted risk. Conclusions: The RF classifier reliably identified KD patients at high risk for IVIG resistance, presenting clinical markers relevant to treatment failure. Evaluation in other patient populations is required to determine whether this risk assessment tool relying on RF has clinical value.

Descriptive epidemiology of children hospitalized for inflammatory bowel disease in Japan: Inpatient database analysis

Inflammatory bowel disease (IBD) – Crohns disease (CD) and ulcerative colitis (UC) – are chronic inflammatory disorders of the intestine. Patients with IBD are at risk of hospitalization for disease exacerbation or IBD‐associated complications. In the pediatric population, however, there are limited data on IBD hospitalizations. We therefore investigated the descriptive epidemiology of hospitalizations relevant to pediatric IBD.

Intussusception secondary to anaphylactic reaction to salmon roe (ikura)

Anaphylactic food reaction often involves gastrointestinal symptoms, such as vomiting and abdominal pain, but to date, there have been no publications documenting the association between food hypersensitivity and intussusception. Herein is reported the case of a 2‐year‐old boy with intussusception accompanied by anaphylactic food reaction. The patient without known allergies complained of severe abdominal pain following ingestion of salmon roe for the first time. Dyspnea, wheezing and generalized urticaria also developed. Subsequently, he had stools containing jelly‐like blood with mucus. At hospital arrival, physical examination identified an abdominal mass in the right lower quadrant; imaging confirmed the diagnosis of colo‐colic intussusception. This patient was successfully treated with enema and no pathological findings were identified via radiology. Laboratory results supported the presence of IgE‐mediated allergy to salmon roe in the present patient. To our knowledge, this is the first report to describe the possible association between intussusception and a hypersensitive food reaction.

Brain edema with clasmatodendrosis complicating ataxia telangiectasia

Ataxia-telangiectasia is a chronic progressive disorder affecting the nervous and immune systems, caused by a genetic defect in the ATM protein. Clasmatodendrosis, a distinct form of astroglial death, has rarely been reported in ataxia-telangiectasia. Neuropathology of our patient disclosed diffuse edema of the cerebral and cerebellar white matter with prominent clasmatodendrosis, implicating ATM in the regulation of astroglial cell death.