Overlapping Features in Kawasaki Disease-Related Arthritis and Systemic-Onset Juvenile Idiopathic Arthritis: A Nationwide Study in Japan.

Background: Arthritis may occur after the diagnosis of Kawasaki disease (KD). Most cases are self-limiting; however, some patients require prolonged treatment. Method: To characterize KD-related arthritis, 14 patients who required arthritis treatment within 30 days after the diagnosis of KD were recruited from the 23rd KD survey in Japan. Twenty-six additional patients were included from our tertiary center and literature review cohorts. Results: The estimated prevalence of KD-related arthritis in Japan was 48 per 100,000 KD patients. Patients with KD-related arthritis had an older age at onset (52 vs. 28 months, P = 0.002) and higher rate of intravenous immunoglobulin (IVIG) resistance in comparison to those without arthritis (86 vs. 17%, P < 0.001). Among 40 patients, 18 had arthritis in the acute phase KD (continued fever-onset type) and 22 did in the convalescent phase (interval fever-onset type). Both showed a similar rate of complete KD or IVIG response. Interval-type patients required biologics for arthritis control less frequently (5 vs. 39%, P = 0.02) and had a higher 2-year off-treatment rate (100 vs. 43%, P = 0.009) than continued-type ones. Interval-types showed lower serum ferritin and interleukin-18 levels than continued-types. When continued-types were grouped according to whether or not they required biologics (n = 7 and n = 11, respectively), the former subgroup had higher ferritin and interleukin-18 levels (P = 0.01 and 0.02, respectively). A canonical discriminant analysis differentiated interval-type from continued-type with the combination of age, time to arthritis, and the ferritin and matrix metalloproteinase-3 levels. Conclusion: Arthritis requiring treatment is a rare complication of KD. KD-associated arthritis includes interval-type (KD-reactive) and continued-type (true systemic-onset juvenile idiopathic arthritis [JIA] requiring biologics), and overlapping arthritis, suggesting the pathophysiological continuity of autoinflammation between KD and JIA.

Distinct genetic clades of enterovirus D68 detected in 2010, 2013, and 2015 in Osaka City, Japan.

The first upsurge of enterovirus D68 (EV-D68), a causative agent of acute respiratory infections (ARIs), in Japan was reported in Osaka City in 2010. In this study, which began in 2010, we surveyed EV-D68 in children with ARIs and analyzed sequences of EV-D68 strains detected. Real-time PCR of 19 respiratory viruses or subtypes of viruses, including enterovirus, was performed on 2,215 specimens from ARI patients (<10 years of age) collected between November 2010 and December 2015 in Osaka City, Japan. EV-D68 was identified in 18 enterovirus-positive specimens (n = 4 in 2013, n = 1 in 2014, and n = 13 in 2015) by analysis of viral protein 1 (VP1) or VP4 sequences, followed by a BLAST search for similar sequences. All EV-D68 strains were detected between June and October (summer to autumn), except for one strain detected in 2014. A phylogenetic analysis of available VP1 sequences revealed that the Osaka strains detected in 2010, 2013, and 2015 belonged to distinct clusters (Clades C, A, and B [Subclade B3], respectively). Comparison of the 5' untranslated regions of these viruses showed that Osaka strains in Clades A, B (Subclade B3), and C commonly had deletions at nucleotide positions 681-703 corresponding to the prototype Fermon strain. Clades B and C had deletions from nucleotide positions 713-724. Since the EV-D68 epidemic in 2010, EV-D68 re-emerged in Osaka City, Japan, in 2013 and 2015. Results of this study indicate that distinct clades of EV-D68 contributed to re-emergences of this virus in 2010, 2013, and 2015 in this limited region.

Japanese Male Siblings with 2-Methyl-3-Hydroxybutyryl-CoA Dehydrogenase Deficiency (HSD10 Disease) Without Neurological Regression.

2-Methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency (HSD10 disease) is a rare X-linked disorder caused by a mutation in the HSD17B10 gene. Fewer than 30 patients with this disorder have been reported worldwide. The classical infantile form of HSD10 disease is characterized by a progressive neurodegenerative course with retinopathy and cardiomyopathy, although HSD10 disease has broad clinical heterogeneity. However, several male patients have not shown neurological regression. Here, we describe two Japanese siblings with HSD10 disease without neurological regression. A 4-year-old boy presented with unconsciousness due to severe hypoglycemia. Laboratory testing on admission showed mild metabolic acidosis and mild hyperammonemia. Urinary organic acid analysis in the acute phase showed elevated excretion of 2-methyl-3-hydroxybutyric acid, tiglylglycine, and ketones. However, 2-methylacetoacetate was not elevated. HSD10 disease was suspected based on urinary organic acid data. The patient had a novel hemizygous c.470C>T (p.A157V) mutation in the HSD17B10 gene. His mother was a heterozygous carrier of this mutation. The patient's older brother also had the c.470C>T (p.A157V) mutation. Neurological development was normal at the time of evaluation. The pilot newborn screening results using tandem mass spectrometry of the proband were reevaluated retrospectively and showed a high C5:1 carnitine level of 0.070 nmol/mL (upper cutoff limit, 0.05 nmol/mL) and a normal C5-OH carnitine level of 0.290 nmol/mL (upper cutoff limit, 1.0 nmol/mL). His affected brother and another patient with the atypical form of HSD10 disease having p.A154T also showed elevated C5:1 but not C5-OH in serum acylcarnitine analysis. Thus, these data suggested that some patients with this disorder may be identified using newborn screening.

Health-related quality of life in Japanese children with acute lymphoblastic leukemia during and after chemotherapy.

BACKGROUND: Quality of life (QOL) as a treatment outcome has not yet been evaluated among patients receiving a specific treatment regimen by treatment phase in a consistent manner. This exploratory cross-sectional study evaluated the QOL of children with acute lymphoblastic leukemia (ALL) receiving one of the most popular treatment regimens in Japan (Japan Association of Childhood Leukemia Study ALL-02 revised protocol). METHODS: Children aged 5-18 years with newly diagnosed B-cell precursor ALL were included. The Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales (PedsQL-J) were completed by children with ALL and their siblings, as well as by age- and sex-matched healthy controls. PedsQL Cancer Module (PedsQL-C) scores were also collected from children with ALL. RESULTS: QOL in children with ALL of the consolidation phase group was significantly decreased compared with that of healthy controls, except in the area of emotional functioning. Regarding the maintenance phase group, QOL impairment was noted in the physical and school functioning, but no differences were noted in social functioning. The off-treatment group had a large effect size only for physical functioning, and the social functioning score was even better in children with ALL than in matched controls. QOL of children with ALL differed with treatment phase. Effect size varied with function and treatment phase. CONCLUSIONS: QOL may change with the progression of treatment, and the timing of these changes varied according to function and problem.

Seasonal variations of respiratory viruses and etiology of human rhinovirus infection in children.

BACKGROUND: Using the polymerase chain reaction (PCR) method it is possible to detect uncultivable viruses and discover multiple viral infections. However, the clinical importance of these findings in relation to symptoms is not known. OBJECTIVES: The seasonal fluctuations of respiratory viruses and the clinical outcomes of single infections and dual infections were investigated. STUDY DESIGN: Nasal aspirate samples were obtained from outpatients and inpatients of a children's hospital and these samples were subjected to real-time PCR to detect 16 respiratory viruses. Seasonal variations of the 16 viruses and the clinical outcomes such as wheezing, the need for oxygenation and prolonged hospitalization of patients with single viral infections and multiple infections were determined for the 5 most often detected viruses. RESULTS: Among 512 specimens analyzed, one or more viruses were detected in 424 (83%) specimens. Two or more viruses were detected in 160 samples (31% of all samples). The epidemic peaks of the viruses did not coincide with each other. Rhinoviruses were the most frequently detected viruses and their coinfection rates were also higher. However, the disease severity in the lower respiratory tract did not differ in most respiratory viral infections regardless of whether there was single infection or dual infection with a rhinovirus and other respiratory virus. CONCLUSIONS: Seasonal distribution was seen for each virus. There were no significant differences in clinical symptoms in the children studied. Because the infection of rhinoviruses is the common occurrence in children, it is hypothesized that the factors related to disease severity are mainly the underlying conditions of the children.

Human parechovirus infections and child myositis cases associated with genotype 3 in Osaka City, Japan, 2014.

Human parechovirus (HPeV) infects humans early in life and typically causes asymptomatic or mild diseases such as gastrointestinal and respiratory illness but sometimes leads to more serious consequences in neonates and young infants. In 2014, we detected HPeV from 38 patients by real-time reverse transcription-PCR in Osaka City, Japan, and 33 HPeV strains were genotyped based on their VP1 sequences. HPeV genotype 3 (HPeV-3) was the most prevalent and accounted for 22 cases (66.7%) followed by nine HPeV-1 (27.3%), one HPeV-2 (3.0%) and one HPeV-4 (3.0%). Phylogenetic analysis revealed that detected HPeV-3 strains were divided into three genetically distinct groups. One was characterized by a novel single amino acid deletion mutation at the N terminus of the 2A protein as well as the VP1 sequence, whereas the others were closely related to HPeV-3 strains detected in Japan in either 2008 or 2011. These HPeV-3 groups were detected from patients with various symptoms including three myositis cases. Recent papers have demonstrated that HPeV-3 was the aetiological agent for epidemic myalgia exclusively among adults from Yamagata Prefecture in Japan. Here, we provide clinical details and episodes of three myositis patients including an adult and two children in Osaka City, Japan. Our results suggest that HPeV-3 is a causative agent of myositis not only in adults but also in children.

Associations between co-detected respiratory viruses in children with acute respiratory infections.

Viruses are the major etiological agents of acute respiratory infections (ARIs) in young children. Although respiratory virus co-detections are common, analysis of combinations of co-detected viruses has never been conducted in Japan. Nineteen respiratory viruses or subtypes were surveyed using multiplex real-time PCR on 1,044 pediatric (patient age < 6 years) ARI specimens collected in Osaka City, Japan between January 2010 and December 2011. In total, 891 specimens (85.3%) were virus positive (1,414 viruses were detected), and 388 of the virus-positive specimens (43.5%, 388/891) were positive for multiple viruses. The ratio of multiple/total respiratory virus-positive specimens was high in children aged 0-35 months. Statistical analyses revealed that human bocavirus 1 and human adenovirus were synchronously co-detected. On the other hand, co-detections of human parainfluenza virus type 1 (HPIV-1) with HPIV-3, HPIV-3 with human metapneumovirus (hMPV), hMPV with respiratory syncytial virus A (RSV A), hMPV with influenza virus A (H1N1) 2009 (FLUA (H1N1) 2009), RSV A with RSV B, and human rhinovirus and FLUA (H1N1) 2009 were exclusive. These results suggest that young children (<3 years) are highly susceptible to respiratory viruses, and some combinations of viruses are synchronously or exclusively co-detected.

Pediatric hospitalizations with influenza A infection during the 2009-2010 pandemic in five hospitals in Japan.

BACKGROUND: The aim of this study was to identify the clinical characteristics of hospitalized children with the 2009 pandemic influenza virus infection in Japan. METHODS: We retrospectively reviewed cases of hospitalized children younger than 16 years with laboratory-confirmed influenza A virus infection during the 2009-2010 pandemic season in five hospitals in Japan. RESULTS: A total of 515 cases were included in the analysis. The median age was 6.3 years (range 0-15), and 216 subjects (41.9%) had one or more underlying medical conditions. There were no fatalities, but 16 patients (3.1%) required intensive care. More than 93% of the subjects received neuraminidase inhibitors, and more than 87% received these medications within 48 h of the onset of symptoms. Approximately 80% of all subjects were admitted to hospital within 48 h of the onset of symptoms. CONCLUSIONS: There were no fatalities, and the proportion of patients with serious illness was substantially lower than previously reported from other countries. Good access to medical services and proactive treatment may have contributed to the lower disease burden of the 2009 influenza pandemic on Japanese children.

Molecular epidemiology of human rhinovirus C in patients with acute respiratory tract infections in Osaka City, Japan.

Human rhinovirus (HRV) is a causative agent of acute respiratory tract infection (ARTI). In 2007, a novel HRV group, HRV-C, was discovered. This study, which assessed whether HRV-C is epidemic among patients with ARTI, was aimed at analyzing the seasonal prevalence of HRV-C in Osaka City, Japan. Gene amplification tests were performed to detect 10 respiratory viruses in 336 specimens collected during November 2008-October 2009. In total, 364 viruses were detected in 271 specimens. The most commonly detected virus was HRV (n = 84). For HRV-positive specimens, we conducted phylogenetic analyses using the VP4/VP2 gene region to identify the HRV species (HRV-C, 30; HRV-A, 54). Both the number and rate of HRV-C detection were highest in December. The highest numbers and the highest rate of HRV-A detection were obtained in April and June and in April, respectively. Statistical analysis showed that the most probable prevalent period of HRV-C was between September and March, and that of HRV-A was between March and November. These results suggest that HRV-C is mainly epidemic during autumn and early spring; this seasonal prevalence was different from that of HRV-A. Moreover, the HRV-C Osaka strains were scattered in many genetic clusters along with previously reported strains from different parts of the world. This result also emphasizes the worldwide circulation of HRV-C.

Enterovirus 68 in children with acute respiratory tract infections, Osaka, Japan.

Enterovirus 68 strains were detected in 14 specimens from children with respiratory tract infections and 1 specimen from a child with febrile convulsions during 2010 in Osaka, Japan. These strains had deletions in the 5' untranslated region and were genetically different from reported strains. This virus is associated with respiratory tract infections in Japan.

Kampo medicines improved blood test and QOL in two vasculitis cases of Churg-Strauss syndrome and Henoch-Shönlein purpura after inadequate treatment with conventional therapies.

OBJECTIVE: Based on the tenets of traditional Chinese medicine (TCM) theory, Kampo medicines were selected and applied to two cases of Churg-Strauss syndrome and Henoch-Shönlein purpura. Two vasculitis syndrome patients exhibited persistent symptoms and abnormal blood tests after treatment with conventional therapies. METHODS: As the two cases had "blood stagnation" and "damps and heat" and one had a "yang deficiency" in terms of TCM theory, we applied certain selected Kampo medicines. RESULTS: In case 1, the patient presented with hypereosinophilia, venous thrombosis, pulmonary infarction, decreased platelet count, ulner nerve palsy and Raynaud's phenomena, which led to a diminished quality of life. After starting the Kampo medicines, the patient improved quickly and recovered within 11 months. In case 2, persistent purpura, abdominal pain, and bloody feces quickly improved and disappeared after Kampo treatment. After starting the Kampo medicines, prednisolone was stopped at 21 days without any sign of relapse to date. CONCLUSION: Kampo medicines helped clear the persistent abnormal symptoms and laboratory findings of vasculitis syndromes, Churg-Strauss syndrome and Henoch-Shönlein purpura, which had responded inadequately to the conventional therapies administered.

Detection of measles virus RNA on SYBR green real-time reverse transcription-polymerase chain reaction.

BACKGROUND: As the coverage rate of the measles vaccine increases, not all patients present the typical symptoms of measles after exposure to the measles virus (MV). The virus loads in clinical specimens from patients with vaccine-modified non-typical measles are expected to be low compared with those of primary MV infection. A rapid and sensitive laboratory procedure is required for diagnosis of measles. METHODS: SYBR Green (TaKaRa) and TaqMan (ABI) real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed to detect MV-RNA. For the real-time RT-PCR, primer sets were designed from a region of the MV H gene of the Edmonston strain (genotype A). A TaqMan probe specific for the H gene of genotype D MV was used. The minimum detectable level of MV-RNA in the SYBR Green and TaqMan real-time RT-PCR assays was evaluated using synthetic MV-RNA. The sensitivity of real-time RT-PCR was compared with that of nested RT-PCR and the virus isolation method using throat swabs and peripheral blood samples from patients with measles. RESULTS: The minimum detectable level of RNA was 10 and 10(2) copies for SYBR Green RT-PCR and TaqMan RT-PCR, respectively. Ten-10(6) copies of standard RNA were linearly detected on SYBR Green RT-PCR. The sensitivity of SYBR Green RT-PCR was equal to that of nested RT-PCR. MV-RNA was detected in virus isolation-negative throat swabs on SYBR Green RT-PCR. CONCLUSION: SYBR Green RT-PCR is a highly sensitive, rapid, and useful diagnostic procedure for the detection of MV.

Evaluation of real-time RT-PCR compared with conventional RT-PCR for detecting human metapneumovirus RNA from clinical specimens.

Human metapneumovirus (hMPV) is an etiologic agent of respiratory tract infections. In this study, we compared the sensitivity and specificity of real-time reverse transcription (RT)-polymerase chain reaction (PCR), conventional RT-PCR, and nested PCR in detecting hMPV genes. A total of 146 clinical specimens from 143 patients who showed acute respiratory tract infection symptoms were tested by real-time RT-PCR, conventional RT-PCR, and nested PCR targeting for the fusion gene. We detected hMPV RNA from 14 (9.6%) clinical specimens (real-time RT-PCR, 8; conventional RT-PCR, 5; and nested PCR, 13). When conventional RT-PCR was the reference standard, the sensitivity and specificity of real-time RT-PCR were 100 and 97.9%, respectively. When nested PCR was the standard, the sensitivity and specificity of real-time RT-PCR were 53.8 and 99.2%, respectively. Therefore, real-time RT-PCR was more sensitive than conventional RT-PCR but less so than nested PCR. Phylogenetic analysis showed that the real-time RT-PCR detected four genetic sublineages of hMPV. These results taken together indicate that real-time RT-PCR is an efficient method for detecting four genetic sublineages of hMPV from clinical specimens.

Co-infection of human metapneumovirus with adenovirus or respiratory syncytial virus among children in Japan.

Human metapneumovirus (hMPV) is one of the etiological agents of acute respiratory tract infections. From June 2005 to May 2006, we collected 185 clinical specimens from children in Osaka City, Japan, and detected 41 hMPV RNA. Of the 41 specimens, four (9.8%) also contained other viruses (3 with adenovirus [AdV] and 1 with respiratory syncytial virus [RSV]). The clinical symptoms of patients coinfected with AdV were indistinct from those of patients mono-infected with hMPV. The symptoms of the one patient co-infected with RSV were clinically severe. Further research is needed to clarify the effect of hMPV on other respiratory viruses or vice versa.

Sensorineural hearing loss in a case of familial hemophagocytic lymphohistiocytosis.

Severe sensorineural hearing loss (bilateral >80 dB) was diagnosed in a case of familial hemophagocytic lymphohistiocytosis (FHL). The female patient developed HLH at 3 months of age and underwent allogeneic cord blood transplantation at 11 months of age following 7 months of immuno-chemotherapy. The type 2 FHL patient had a homozygous perforin gene mutation of 1090-1091delCT, and was noted to have hearing loss at 3.5 years of age. Retrospective evaluation did not clarify the exact causes of hearing loss. Reports on Kawasaki disease, suggesting a correlation between severe inflammatory status in infancy and the development of sensorineural hearing loss, may shed some light on this rare complication in this case of FHL. Considering the markedly improved prognosis of FHL due to recent advances made in the molecular diagnosis and in the management including allogeneic hematopoietic stem cell transplantation, auditor by screening might be warranted for surviving FHL patients.

Detection of adenovirus DNA in throat swabs and blood by SYBR green real-time PCR assay in patients with adenovirus-associated tonsillitis.

The adenovirus DNA load ranged from 10(5) to 10(10) copy/mL and from 10(4) to 10(7) copy/mL in throat swabs and blood from patients with adenovirus-associated exudative tonsillitis, respectively. The copy number of adenovirus DNA in blood was positively correlated with the duration of the fever.

Clinical and genetic analyses of presumed Shwachman-Diamond syndrome in Japan.

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disorder characterized by exocrine pancreatic insufficiency, bone marrow dysfunction, and skeletal abnormalities. SBDS was identified as a causative gene for SDS in 2003, and genetic analyses of SDS have been performed. We performed genetic analysis of 13 Japanese patients with presumed SDS and found that 10 of them had SBDS mutations. Most patients had recurrent mutations (181-184TA-->CT and 258+2T-->C); however, 2 patients had unique mutations (259-1G-->A and 428C-->G). Although genetic analysis is useful for definitive diagnosis and for genetic counseling of SDS patients and families, SDS appears to be a genetically heterogeneous disorder. In addition, presumed SDS patients without SBDS mutations may be included in other disorders.

Improved outcome in the treatment of pediatric multifocal Langerhans cell histiocytosis: Results from the Japan Langerhans Cell Histiocytosis Study Group-96 protocol study.

BACKGROUND: The treatment outcome of multifocal childhood Langerhans cell histiocytosis (LCH) has not been satisfactory and has resulted in poor therapeutic responses with high mortality and a high incidence of reactivation with late sequelae. To overcome these issues, the Japan LCH Study Group-96 (JLSG-96) protocol was conducted prospectively from 1996 to 2001 in Japan. METHODS: Newly diagnosed children with multifocal LCH were classified into 2 groups: a single-system multisite (SS-m) group and a multisystem (MS) group. All patients initially were treated on Protocol A, which consisted of 6 weeks of induction therapy with combined cytosine arabinoside, vincristine (VCR), and prednisolone (PSL) followed by 6 months of maintenance therapy. Patients who had a poor response to the induction of Protocol A were switched to a salvage regimen (Protocol B), which consisted of an intensive combination of doxorubicin, cyclophosphamide, VCR, and PSL. RESULTS: In total, 91 patients were treated, including 32 patients in the SS-m group and 59 patients in the MS group. At the median 5-year follow-up, 96.9% of patients in the SS-m group and 78.0% of patients in the MS group had good response status. Diabetes insipidus developed in 3.1% of patients in the SS-m group and in 8.9% of patients in the MS group. The overall survival rate at 5 years for the SS-m and MS groups was 100% and 94.4% +/- 3.2%, respectively. CONCLUSIONS: The JLSG-96 protocol attained very low mortality for pediatric patients with multifocal LCH.

Seasonal distribution and phylogenetic analysis of human metapneumovirus among children in Osaka City, Japan.

BACKGROUND: Human metapneumovirus (hMPV) is one of the etiological agents of respiratory tract infection (RTI). Because clinical symptoms of hMPV resemble those caused by respiratory syncytial virus (RSV), clinical diagnosis of hMPV infection is difficult. Moreover, hMPV isolation using cultured cells is generally difficult and not efficient compared with reverse transcription-PCR (RT-PCR). OBJECTIVES: To assess infection and seasonal distribution of hMPV associated with RTI among children in Osaka City, Japan. STUDY DESIGN: To detect the hMPV gene, we extracted viral RNA from clinical specimens of patients with RTI and performed RT-PCR or nested-PCR for the fusion (F) gene. hMPV-specific amplicons were sequenced and subjected to phylogenetic analysis. RESULTS: From June 2004 to May 2005, we detected 29 (20.1%) hMPV strains among 144 clinical specimens. Fifteen strains were detected by RT-PCR and the remaining 14 by nested-PCR. Prevalence was principally in winter and spring with incidence peaking in April. We also detected the hMPV RNA from a patient with encephalitis. Approximately 80% of the hMPV-positive patients were younger than 3 years. To analyze these isolates precisely, a phylogenetic analysis using F gene was performed and demonstrated that Osaka City isolates of hMPV consists of two major genetic lineages each comprising two sublineages. CONCLUSIONS: We found two major genetic lineages of hMPV in Osaka City, Japan. We also found that nested-PCR was an efficient method for detecting the hMPV gene in clinical specimens. Of the 28 patients presenting with hMPV infection, 1 patient had associated encephalitis suggesting that hMPV infection might play a role in inducing encephalitis.