Normative Data and Predictive Equation of Interrupter Airway Resistance in Preschool Children in Japan.

Measurement of interrupter airway resistance (Rint) is a convenient alternative to standard spirometry for assessing respiratory function in uncooperative young children. The aim of the present prospective study was to establish the normative data and predictive equation of Rint in Japanese preschool children. A total of 214 children were enrolled from a single kindergarten; however, 129 were excluded because they met at least 1 of the exclusion criteria, such as wheezing history or recent common cold. Expiratory Rint values were assessed in 85 of the children, but technically unsatisfactory measurements were obtained in 5 of them. Thus, 80 healthy Japanese children (39 boys and 41 girls) without any history or symptoms of respiratory tract diseases were evaluated. Their age, body height, and body weight ranges (median) were 1.67 to 6.42 (4.38) years, 79.8 to 120.9 (102.5) cm, and 10.4 to 24.9 (15.8) kg, respectively. The mean Rint was 0.93±0.25 kPa/L/s (range=0.46-1.49 kPa/L/s). The Rint tended to decrease with increasing age and body height (r=-0.65; P<0.01), but sex played no significant role (P=0.71). The predictive equation based on body height derived by linear regression was expiratory Rint (kPa/L/s) =2.513-0.01567×body height (cm) (multiple correlation coefficient=0.653). Because 79 of the 80 measured Rint values were within 140% of the predictive Rint value, we calculated a 140% cut-off for predicting bronchoconstriction. Our results provide a reference value for evaluating the degree of airway obstruction in young Japanese children.

Simple diagnosis of STAT1 gain-of-function alleles in patients with chronic mucocutaneous candidiasis.

CMCD is a rare congenital disorder characterized by persistent or recurrent skin, nail, and mucosal membrane infections caused by Candida albicans. Heterozygous GOF STAT1 mutations have been shown to confer AD CMCD as a result of impaired dephosphorylation of STAT1. We aimed to identify and characterize STAT1 mutations in CMCD patients and to develop a simple diagnostic assay of CMCD. Genetic analysis of STAT1 was performed in patients and their relatives. The mutations identified were characterized by immunoblot and reporter assay using transient gene expression experiments. Patients' leukocytes are investigated by flow cytometry and immunoblot. Six GOF mutations were identified, three of which are reported for the first time, that affect the CCD and DBD of STAT1 in two sporadic and four multiplex cases in 10 CMCD patients from Japan. Two of the 10 patients presented with clinical symptoms atypical to CMCD, including other fungal and viral infections, and three patients developed bronchiectasis. Immunoblot analyses of patients' leukocytes showed abnormally high levels of pSTAT1 following IFN-γ stimulation. Based on this finding, we performed a flow cytometry-based functional analysis of STAT1 GOF alleles using IFN-γ stimulation and the tyrosine kinase inhibitor, staurosporine. The higher levels of pSTAT1 observed in primary CD14(+) cells from patients compared with control cells persisted and were amplified by the presence of staurosporine. We developed a flow cytometry-based STAT1 functional screening method that would greatly facilitate the diagnosis of CMCD patients with GOF STAT1 mutations.

Fatal tracheo-innominate artery fistula after tracheostomy in a patient with Pelizaeus-Merzbacher disease.

Tracheo-innominate artery fistula (TIF) is a serious, life-threatening complication following tracheostomy. We report a fatal TIF in a 15-year-old girl with Pelizaeus-Merzbacher disease. She received a tracheostomy for prolonged translaryngeal intubation due to acute respiratory failure without a trial of noninvasive ventilatory support before intubation. Severe hemorrhage from the TIF occurred 6 months after tracheostomy; immediate resuscitation failed. Antemortem fiberoptic bronchoscopy showed tracheal stenosis accompanied by granulation tissue, and postmortem examination revealed TIF with ulcerative granulation. Preventive intervention is required to avoid catastrophic TIF due to its high mortality rate. Moreover, to avoid prolonged translaryngeal intubation leading to tracheostomy, noninvasive ventilatory support before translaryngeal intubation, if applicable, is beneficial.

Serum KL-6 and surfactant protein D in children with 2009 pandemic H1N1 influenza infection.

BACKGROUND: A global pandemic influenza A (H1N1) outbreak occurred in 2009. Rapid progress of respiratory distress is one of the characteristic features of pandemic influenza A (H1N1) infection. The physiologic mechanism causing hypoxia in pandemic influenza A (H1N1) infection, however, has not been elucidated. METHODS: The serum levels of KL-6 and surfactant protein D (SP-D) were evaluated in 21 cases of pandemic influenza A (H1N1) infection associated with chest radiographic abnormality in order to estimate alveolar involvement. The clinical features were also analyzed. RESULTS: All of the patients had high fever, and rapidly progressed to respiratory distress within several days of disease onset. Despite mild radiographic abnormality in these patients, dyspnea was severe and they had low blood oxygen saturation levels. Many of the patients had a history of allergic diseases including asthma. Serum KL-6 and SP-D levels on admission were 191 ± 69 U/mL and 32.6 ± 18.9 ng/mL, respectively. These two levels were still below the upper normal limit 1 week later. There were no clear relationships between specific clinical symptoms and KL-6 or SP-D levels. All patients were treated with oseltamivir and/or zanamivir, and improved without mechanical ventilation management. CONCLUSION: KL-6 and SP-D elevation were not significant in pandemic influenza A (H1N1) infection associated with chest radiographic abnormality. In pandemic influenza A (H1N1) infection, alveolar involvement was estimated to be little, and severe respiratory distress was probably caused by obstruction of peripheral bronchi.

Relapsing autoimmune pancreatitis in a 14-year-old girl.

We present a case of acute pancreatitis in a 14-year-old girl which fulfilled the diagnostic criteria of autoimmune pancreatitis (AIP) and responded to corticosteroid therapy. Imaging studies revealed that the main pancreatic duct was narrow in the head of the pancreas but had been dilated in the body at an earlier stage. The pancreatitis recurred twice when the prednisolone dose was reduced to 10 mg or less but responded each time to an increased dose and has been kept under control with low-dose prednisolone therapy for 3 years since onset. Repeated magnetic resonance cholangiopancreatography during steroid therapy revealed an improvement of the narrowing of the main pancreatic duct in the head and dilation of the duct in the body. AIP in younger patients has distinct clinical features, such as presentation with epigastralgia, back pain without jaundice, and elevated serum amylase levels. The serum level of IgG4 is rarely increased in young patients, indicating a different disease mechanism than for cases in elderly patients. Given the excellent response of this condition to steroid therapy, AIP should be considered even in young children and adolescents when the diagnosis of idiopathic pancreatitis is suggested.

A deep intronic mutation in the SLC12A3 gene leads to Gitelman syndrome.

Many mutations have been detected in the SLC12A3 gene of Gitelman syndrome (GS, OMIM 263800) patients. In previous studies, only one mutant allele was detected in approximately 20 to 41% of patients with GS; however, the exact reason for the nonidentification has not been established. In this study, we used RT-PCR using mRNA to investigate for the first time transcript abnormalities caused by deep intronic mutation. Direct sequencing analysis of leukocyte DNA identified one base insertion in exon 6 (c.818_819insG), but no mutation was detected in another allele. We analyzed RNA extracted from leukocytes and urine sediments and detected unknown sequence containing 238bp between exons 13 and 14. The genomic DNA analysis of intron 13 revealed a single-base substitution (c.1670-191C>T) that creates a new donor splice site within the intron resulting in the inclusion of a novel cryptic exon in mRNA. This is the first report of creation of a splice site by a deep intronic single-nucleotide change in GS and the first report to detect the onset mechanism in a patient with GS and missing mutation in one allele. This molecular onset mechanism may partly explain the poor success rate of mutation detection in both alleles of patients with GS.

An 8-year-old boy with vertebral artery dissection with cerebellar ataxia featuring suspected vertebral artery hypoplasia.

We report an 8-year-old boy with left vertebral artery dissection featuring cerebellar ataxia in which congenital vertebral artery hypoplasia was suspected as a predisposing factor in the dissection. The patient suddenly suffered from vertigo and vomiting while swimming, and he was brought to our department. The initial brain Computed Tomography (CT) demonstrated no abnormalities, and his symptoms disappeared the next morning. However, one month after onset, brain Magnetic Resonance Imaging (MRI) revealed ischemic changes (infarction) in the left cerebellum. Transfemoral angiography showed complete occlusion at the C2 portion of the left vertebral artery, suggesting dissection and diffuse narrowing of the proximal segment of the occlusion site. Three-dimensional CT angiography also revealed diffuse narrowing of the left vertebral artery from the bifurcation of the subclavian artery. He has since been living daily life without any difficulties. The detailed etiology of cerebral artery dissection remains unknown, but arterial anomalies should be considered as a predisposing factor.

Possible synergic effect of angiotensin-I converting enzyme gene insertion/deletion polymorphism and angiotensin-II type-1 receptor 1166A/C gene polymorphism on ischemic heart disease in patients with Kawasaki disease.

ACE I/D and AT1R 1166A/C polymorphisms are considered to comprise individual risk factors for the development of coronary disease. We sought to demonstrate that the ACE I/D and AT1R 1166A/C polymorphisms affect coronary artery stenosis in patients with Kawasaki disease (KD). We examined 147 healthy controls and 281 Japanese children with KD. The patients were further divided into group N (n = 246, no ischemia) and group I (n = 35, severe coronary artery stenosis with myocardial ischemia), and we studied the genotype of ACE I/D and AT1R 1166A/C polymorphisms. We also examined ACE activity in patients with acute KD. We did not detect any prevalent genotypes of the ACE and AT1R polymorphisms between controls and KD patients. However, the prevalence of the D allele in the ACE polymorphism and of the C allele in the AT1R polymorphism tended to be higher in group I than in group N (odds ratios, 2.00 and 2.32, respectively). In addition, the presence of the D and/or C alleles significantly increased the relative risk of developing myocardial ischemia (odds ratio, 2.71; p = 0.038). During the convalescent phase of KD, ACE activity was increased despite significant attenuation during the acute phase. These results suggested that the renin-angiotensin system is associated with the formation of severe coronary artery stenosis and myocardial ischemia.

Serum KL-6 levels in pediatric patients: reference values for children and levels in pneumonia, asthma, and measles patients.

Serum KL-6 reflects alveolar damage and regeneration of type II pneumocytes, indicating disease activity in various interstitial lung diseases. We conducted a descriptive and observational multiple case-control study to determine the distribution of serum KL-6 levels in pediatric patients with or without respiratory diseases. Subjects were recruited from the patients of a teaching hospital in the suburb of Tokyo. A consecutive series of 401 children (0-16 years old) underwent blood sampling for many clinical reasons. They comprised the following four groups: pneumonia (n = 96), bronchial asthma (n = 101), measles (n = 102), and nonrespiratory diseases (n = 102) as a control group. Standard upper limits of serum KL-6 in a group of children with nonrespiratory disease were 250 U/mL, or half the adult level. No gender or age differences were observed. Elevated serum KL-6 concentrations were observed in severe pneumonia, acute exacerbations of asthma, and measles pneumonia. In the measles group, KL-6 values reflected the presence and severity of complicating pneumonia. We conclude that serum KL-6 levels exceeding 250 U/mL were rarely observed in children without respiratory diseases. In contrast, a substantial proportion of children with common respiratory diseases showed mild to moderate increases in serum KL-6 levels. Elevated serum KL-6 in these children may reflect the presence of alveolar damage, followed by regeneration of type II pneumocytes. However, in order to use serum KL-6 as a marker of interstitial lung diseases in children, a cutoff level should be determined separately.