A first-in-human study of the anti-inflammatory profibrinolytic TMS-007, an SMTP family triprenyl phenol.

AIMS: TMS-007, an SMTP family member, modulates plasminogen conformation and enhances plasminogen-fibrin binding, leading to promotion of endogenous fibrinolysis. Its anti-inflammatory action, mediated by soluble epoxide hydrolase inhibition, may contribute to its efficacy. Evidence suggests that TMS-007 can effectively treat experimental thrombotic and embolic strokes with a wide time window, while reducing haemorrhagic transformation. We aim to evaluate the safety, pharmacokinetics and pharmacodynamics of TMS-007 in healthy volunteers. METHODS: This was a randomized, placebo-controlled, double blind, dose-escalation study, administered as a single intravenous infusion of TMS-007 in cohorts of healthy male Japanese subjects. Six cohorts were planned, but only five were completed. In each cohort (n = 8), individuals were randomized to receive one of five doses of TMS-007 (3, 15, 60, 180 or 360 mg; n = 6) or placebo (n = 2). RESULTS: TMS-007 was generally well tolerated, and no serious adverse events were attributed to the drug. A linear dose-dependency was observed for plasma TMS-007 levels. No symptoms of bleeding were observed on brain MRI analysis, and no bleeding-related responses were found on laboratory testing. The plasma levels of the coagulation factor fibrinogen and the anti-fibrinolysis factor α2 -antiplasmin levels were unchanged after TMS-007 dosing. A slight increase in the plasma level of plasmin-α2 -antiplasmin complex, an index of plasmin formation, was observed in the TMS-007 group in cohort 2. CONCLUSIONS: TMS-007 is generally well tolerated and exhibits favourable pharmacokinetic profiles that warrant further clinical development.

Preclinical safety, toxicokinetics and metabolism of BIIB131, a novel prothrombolytic agent for acute stroke.

BIIB131, a small molecule, is currently in Phase 2 for the treatment of acute ischemic stroke. Safety and metabolism of BIIB131 were evaluated following intravenous administration to rats and monkeys. Exposure increased dose-proportionally in rats up to 60 mg/kg and more than dose-proportionally in monkeys at greater than 10 mg/kg accompanied by prolonged half-life and safety findings. The BIIB131 was poorly metabolized in microsomes with no inhibition of CYPs. BIIB131-glucuronide, formed by UGT1A1, accounted for 21.5% metabolism in human hepatocytes and 28-40% in rat bile. In rats, excretion was primarily via the bile. BIIB131 inhibited the hERG and Nav1.5 cardiac channels by 39% but showed no effect on cardiovascular parameters in monkeys. Toxicology findings were limited to reversable hematuria, changes in urinary parameters and local effects. A MTD of 30 mg/kg was established in monkeys, the most sensitive species, at total plasma Cmax and AUC of 6- and 14-fold, respectively, greater than the NOAEL. The Phase 1 study started with intravenous 0.05 mg/kg and ascended to 6.0 mg/kg which corresponded to safety margins of 147- to 0.9-fold (for Cmax) within the linear drug exposure. Thus, the preclinical profile of BIIB131 has been appropriately characterized and supports its further clinical development.

The clinical characteristics of pediatric coronavirus disease 2019 in 2020 in Japan.

BACKGROUND: The COVID-19 pandemic has affected the lives of people of all ages. Most reports on pediatric cases suggest that children experience fewer and milder symptoms than do adults. This is the first nationwide study in Japan focusing on pediatric cases reported by pediatricians, including cases with no or mild symptoms. METHODS: We analyzed the epidemiological and clinical characteristics and transmission patterns of 840 pediatric (<16 years old) COVID-19 cases reported between February and December 2020 in Japan, using a dedicated database which was maintained voluntarily by members of the Japan Pediatric Society. RESULTS: Almost half of the patients (47.7%) were asymptomatic, while most of the others presented mild symptoms. At the time of admission or first outpatient clinic visit, 84.0% of the cases were afebrile (<37.5°C). In total, 609 cases (72.5%) were exposed to COVID-19-positive household members. We analyzed the influence of nationwide school closures that were introduced in March 2020 on COVID-19 transmission routes among children in Japan. Transmission within households occurred most frequently, with no significant difference between the periods before and after declaring nationwide school closures (70.9% and 74.5%, respectively). CONCLUSIONS: COVID-19 symptoms in children are less severe than those in adults. School closure appeared to have a limited effect on transmission. Controlling household transmission from adult family members is the most important measure for prevention of COVID-19 among children.

Rotavirus Vaccination Can Be Performed Without Viral Dissemination in the Neonatal Intensive Care Unit.

Background: This study was conducted to assess the transmissibility of rotavirus vaccine strains after rotavirus vaccination in a neonatal intensive care unit (NICU). Methods: Pentavalent (RV5) or monovalent (RV1) rotavirus vaccine was administered to infants admitted to the NICU. Nineteen vaccinated infants and 49 unvaccinated infants whose beds were located in close proximity to the vaccinated infants were enrolled in this study. Dissemination and fecal shedding of vaccine viruses within the NICU were examined using real-time reverse transcription-polymerase chain reaction. Results: Shedding of the vaccine strain was detected in all 19 vaccinated infants. RV5 virus shedding started 1 day after the first vaccination and persisted for 8 days after the first vaccination, and viral shedding terminated by day 5 after administration of the second RV5 dose. The kinetics of RV1 virus shedding differed among vaccinated infants. The duration of RV1 virus shedding was longer after the first vaccination than after the second vaccination. In contrast to the vaccinated infants, no vaccine virus genomes were detected in any of the stool samples collected from the 49 unvaccinated infants. Conclusions: This study is direct evidence of no transmission of rotavirus vaccine strains between vaccinated infants and unvaccinated infants in close proximity within a NICU.

Cooperation of Sall4 and Sox8 transcription factors in the regulation of the chicken Sox3 gene during otic placode development.

To elucidate the transcriptional regulation that underlies specification of the otic placode, we investigated the Sox3 downstream enhancer Otic1 of the chicken, the activity of which is restricted to and distributed across the entire otic placode. The 181-bp Otic1 enhancer sequence was dissected into a 68-bp minimal activating sequence, which exhibited dimer enhancer activity in the otic placode and cephalic neural crest, and this was further reduced to a 25-bp Otic1 core sequence, which also showed octamer enhancer activity in the same regions. The Otic1 core octamer was activated by the combined action of Sall4 and the SoxE transcription factors (TFs) Sox8 or Sox9. Binding of Sall4, Sox8 and Sox9 to the Otic1 sequence in embryonic tissues was confirmed by ChIP-qPCR analysis. The core-adjoining 3' side sequences of Otic1 augmented its enhancer activity, while inclusion of the CAGGTG sequence in the immediate 3' end of the 68-bp sequence repressed its enhancer activity outside the otic placode. The CAGGTG sequence likely serves as the binding sites of the repressor TFs δEF1 (Zeb1), Sip1 (Zeb2), and Snail2, all of which are expressed in the cephalic neural crest but not in the otic placode. Therefore, the combination of Sall4-Sox8-dependent activation and CAGGTG sequence-dependent repression determines otic placode development. Although the Otic1 sequence is not conserved in mammals or fishes, the activation mechanism is, as Otic1 was also activated in otic placode tissues developed from mouse embryonic stem cells and transient transgenic zebrafish embryos.

Role of matrix metalloproteinases in the pathogenesis of childhood gastroenteritis.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been implicated in the pathogenesis of gastrointestinal diseases, such as rotavirus gastroenteritis (GE). Kinetics of these biomarkers were examined in paired serum samples collected from bacterial enteritis patients with Campylobacter (n = 2) and Salmonella (n = 4) and viral GE patients with rotavirus (n = 27), norovirus (n = 25), and adenovirus (n = 11). At the time of hospital admission, all viral GE patients demonstrated increased MMP-9 and decreased MMP-2 and TIMP-2 serum levels. In contrast to viral GE patients, serum MMP-9 levels were not elevated at the time of hospital admission but elevated at the time of discharge; serum MMP-2 and TIMP-2 levels were decreased both at the time of admission and discharge in bacterial enteritis patients. Interestingly, the kinetics of serum MMP-2, MMP-9, and TIMP-2 levels were similar among the viral GE patients but distinct from bacterial enteritis patients. Thus, the involvement of MMPs and TIMPs in the pathophysiology of gastrointestinal symptoms likely varies depending on the etiological agent. Further studies are required to verify whether the extent of the bacterial enteritis or age of the patients influences these serum biomarkers. J. Med. Virol. 88:1341-1346, 2016. © 2016 Wiley Periodicals, Inc.

A Novel IgM-capture enzyme-linked immunosorbent assay using recombinant Vag8 fusion protein for the accurate and early diagnosis of Bordetella pertussis infection.

An ELISA that measures anti-PT IgG antibody has been used widely for the serodiagnosis of pertussis; however, the IgG-based ELISA is inadequate for patients during the acute phase of the disease because of the slow response of anti-PT IgG antibodies. To solve this problem, we developed a novel IgM-capture ELISA that measures serum anti-Bordetella pertussis Vag8 IgM levels for the accurate and early diagnosis of pertussis. First, we confirmed that Vag8 was highly expressed in all B. pertussis isolates tested (n = 30), but little or none in other Bordetella species, and that DTaP vaccines did not induce anti-Vag8 IgG antibodies in mice (i.e. the antibody level could be unaffected by the vaccination). To determine the immune response to Vag8 in B. pertussis infection, anti-Vag8 IgM levels were compared between 38 patients (acute phase of pertussis) and 29 healthy individuals using the anti-Vag8 IgM-capture ELISA. The results revealed that the anti-Vag8 IgM levels were significantly higher in the patients compared with the healthy individuals (P < 0.001). ROC analysis also showed that the anti-Vag8 IgM-capture ELISA has higher diagnostic accuracy (AUC, 0.92) than a commercial anti-PT IgG ELISA kit. Moreover, it was shown that anti-Vag8 IgM antibodies were induced earlier than anti-PT IgG antibodies on sequential patients' sera. These data indicate that our novel anti-Vag8 IgM-capture ELISA is a potentially useful tool for making the accurate and early diagnosis of B. pertussis infection.

Familial acute necrotizing encephalopathy without RANBP2 mutation: Poor outcome.

Most childhood cases of acute necrotizing encephalopathy (ANE) involve neither family history nor recurrence. ANE occasionally occurs, however, as a familial disorder or recurs in Caucasian patients. A mutation of RAN-binding protein 2 (RANBP2) has been discovered in more than one half of familial or recurrent ANE patients. In contrast, there has been no report of this mutation in East Asia. Here, we report the first sibling cases of typical ANE in Japan, with poor outcome. DNA analysis of genes associated with ANE or other encephalopathies, including RANBP2 and carnitine palmitoyl transferase II (CPT2), indicated neither mutations nor disease-related polymorphisms. On literature review, recurrent or familial ANE without the RANBP2 mutation has a more severe outcome and greater predilection for male sex than that with the RANBP2 mutation. This suggests that there are unknown gene mutations linked to ANE.

[Results of Booster Vaccination in Children with Primary Vaccine Failure after Initial Varicella Vaccination].

In October 2014, the varicella vaccination policy in Japan was changed from a single voluntary inoculation to two routine inoculations. This paper reports the results of booster vaccination in children who did not show seroconversion after initial vaccination (i.e., primary vaccine failure : PVF) over a 7-year period prior to the introduction of routine varicella vaccination. Between November 2007 and May 2014, 273 healthy children aged between 1.1 and 14.5 years (median : 1.7 years) underwent varicella vaccination. Before and 4 to 6 weeks after vaccination, the antibody titers were measured using an immune adherence hemagglutination (IAHA) assay and a glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). In addition, side reactions were examined during the four-week period after vaccination. Children who did not show IAHA seroconversion (PVF) were recommended to receive a booster vaccination, and the measurement of antibody titers and an assessment of side reactions were performed after the booster dose. In May 2015, a questionnaire was mailed to each of the 273 participants to investigate whether they had developed varicella and/or herpes zoster after vaccination. After initial vaccination, the IAHA seroconversion rate was 75% and the mean antibody titer (Log2) with seroconversion was 4.7, while the gpELISA seroconversion rate was 84% and the mean antibody titer (Log10) with seroconversion was 2.4. Among children with PVF, 54 received booster vaccination within 81 to 714 days (median : 139 days) after the initial vaccination. After booster vaccination, the IAHA seroconversion rate was 98% and the mean antibody titer (Log2) with seroconversion was 5.8. Both the seroconversion rate and the antibody titer were higher compared with the values after the initial vaccination (p < 0.01). After booster vaccination, the gpELISA seropositive rate was 100% and the mean positive antibody titer (Log 10) was 3.6 ; similar results were obtained for the IAHA assay, with a significantly higher, antibody response than that after the initial vaccination (p < 0.01). Side reactions were generally minor, including fever (≥ 37.5 degrees C), rash at the injection site, and rash at other sites. There were no significant differences in the incidences of side reactions between the initial and booster vaccinations. A total of 185 participants responded to the questionnaire (response rate : 68%), and the period between receiving the initial vaccination and their response to the questionnaire ranged from 1.0 to 7.5 years (median : 4.0 years). The prevalence of breakthrough varicella after the initial vaccination was 17% among seroconverters who did not receive booster vaccination and 14% among non-seroconverters who received booster vaccination, showing no significant difference between the two groups. In conclusion, there are no safety issues regarding the administration of a booster vaccination to children with PVF after an initial varicella vaccination, and,a good antibody response can be expected.

Psychosocial profiles of children with achondroplasia in terms of their short stature-related stress: a nationwide survey in Japan.

AIMS AND OBJECTIVES: To assess psychosocial profiles of children with achondroplasia using a nationwide survey. BACKGROUND: Achondroplasia, showing short stature and disproportionately short limbs, causes physical inconvenience such as difficulty in reaching high objects. It is, however, still controversial whether the condition is associated with psychological problems, especially in childhood. DESIGN: A cross-sectional descriptive design was employed. METHODS: To evaluate psychosocial profiles and adaptation processes in children with achondroplasia, we developed an inventory of scales based on the psychological stress model of which conceptual framework was comprised of stressor, coping process, coping resource and adaptation outcome domains. Participants were recruited nationwide through the largest advocacy support group for achondroplasia in Japan. Of the 130 group members, 73 X-ray-diagnosed patients, aged 8-18 years, completed the inventory of questionnaires to be analysed. RESULTS: As for the stressor domain, patients experienced short stature-related unpleasant experiences more frequently (z-score: +1·3 in average, +3·9 in physical inconvenience). Nevertheless, these experiences had little effect on the coping process (threat appraisal: -0·2, control appraisal: +0·1) and the adaptation outcome (stress response: +0·3, self-concept: 0·0). Interestingly, self-efficacy in the coping resource domain was noticeably increased (+3·1) and was strongly correlated with most variables in the coping process and in adaptation outcome domains. CONCLUSIONS: Although the children with achondroplasia experienced more short stature-related stressors, there was no evidence of any psychosocial maladaptation. This finding suggests that coping process as well as coping resources such as self-efficacy could be important targets for promoting psychological adjustment in children with achondroplasia. RELEVANCE TO CLINICAL PRACTICE: To help children with achondroplasia adapt socially, nurses and other healthcare providers should routinely assess their psychological adaptation process, especially cognitive appraisal and self-efficacy.

[Immunogenicity of additional varicella vaccination 3-5 years after the initial vaccination].

Additional varicella vaccination was carried out targeting 16 subjects who had immune adherence hemagglutination (IAHA) seroconversion following the initial varicella vaccination and did not contract breakthrough varicella after the initial vaccination. The median ages at the initial and additional vaccination were 2.1 (1.1-6.9) years old and 6.1 (4.4-10.5) years old, respectively. The mean interval between the initial and additional vaccination was 4.0 (3.2-5.2) years. IAHA and glycoprotein-based enzyme-linked immunosorbent assay (gpELISA) antibody titers were measured just before and 4-6 weeks after the additional vaccination. Side reaction was surveyed at four weeks after the additional vaccination, and compared with the results at the initial vaccination. IAHA and gpELISA seroconversion rates at the initial vaccination were 100% and 88% respectively. Prior to the additional vaccination, IAHA antibody titers significantly decreased in 50% of the subjects, and became negative in 38% of the subjects. On the other hand, a significant increase in IAHA antibody titers was observed in 25% of the subjects, and this is assumed to be the result of a subclinical infection after the initial vaccination. The positive rate of both antibodies after the additional vaccination was 100%, the mean IAHA antibody titer (Log2) after the initial/additional vaccination in seropositive subjects was 4.6/6.5, and the mean gpELISA antibody titer (Log10) was 2.3/4.0. The mean IAHA and gpELISA antibody titers were higher after the additional vaccination than after the initial vaccination (p < 0.01, p < 0.01). This is considered to be the booster effect due to the additional vaccination. At 0-2 days after the additional vaccination, a rash at the injection site was observed in 56% of the subjects, higher than the incidence after the initial vaccination (13%) (p < 0.05), but no severe systemic side reactions were observed at either the initial or the additional vaccination. In conclusion, an additional varicella vaccination 3-5 years after the initial vaccination is thought to have greater immunogenicity and is considered effective.

Anti-varicella-zoster virus antibody titers and seroprotection status from before the first dose of varicella vaccination to before entering elementary school in one region in Japan.

OBJECTIVE: We aimed to examine changes in anti-varicella-zoster virus (VZV) antibody titers and seroprotection status from before the first dose of vaccination to before 7 years old entering elementary school in children who received the routine two-dose varicella vaccination. METHODS: Participants were 37 healthy children who received the routine two-dose varicella vaccination at our hospital. A total of five serum samples per child were collected immediately before and 4-6 weeks after each dose of the vaccination and in the year before entry to elementary school. We measured anti-VZV antibody titers by immune adherence hemagglutination (IAHA) method and glycoprotein-based enzyme-linked immunosorbent assay (gpELISA). A positive antibody titer and the seroprotection level were set as ≥2-fold and ≥16-fold, respectively, for IAHA antibody and as ≥50 units and ≥105 units, respectively, for gpELISA-IgG antibody. RESULTS: The rates of IAHA antibody positivity in the five samples (in order of collection) were 0%, 65%, 38%, 100%, and 59%, and the rates of seroprotection were 0%, 43%, 8%, 100%, and 43%. The rates of gpELISA-IgG antibody positivity were 8%, 81%, 89%, 100%, and 100%, and the rates of seroprotection were 5%, 54%, 70%, 100%, and 89%. The mean IAHA antibody titer and mean gpELISA-IgG antibody titer before entering elementary school were both lower than the respective titers obtained after the second vaccination (both p < 0.01). CONCLUSIONS: Routine two-dose varicella vaccination leads to good antibody production, but titers of acquired antibodies decrease before children enter elementary school.

Acute and Postacute Clinical Characteristics of Coronavirus Disease 2019 in Children in Japan.

BACKGROUND: The clinical features of coronavirus disease 2019 (COVID-19) in children have been changing because of the emergence and rapid spread of variants of concern (VOC). The increase in cases infected with VOC has brought concern with persistent symptoms after COVID-19 in children. This survey aimed to analyze the clinical manifestations and persistent symptoms of pediatric COVID-19 cases in Japan. METHODS: We analyzed the clinical manifestations of pediatric COVID-19 cases reported between February 2020 and April 2022 in Japan, using a dedicated database updated voluntarily by the members of the Japan Pediatric Society. Using the same database, we also analyzed persistent symptoms after COVID-19 in children who were diagnosed between February 2020 and November 2021. RESULTS: A total of 5411 and 1697 pediatric COVID-19 cases were included for analyzing clinical manifestations and persistent symptoms, respectively. During the Omicron variant predominant period, the percentage of patients with seizures increased to 13.4% and 7.4% in patient groups 1-4 and 5-11 years of age, respectively, compared with the pre-Delta (1.3%, 0.4%) or Delta period (3.1%, 0.0%). Persistent and present symptoms after 28 days of COVID-19 onset were reported in 55 (3.2%). CONCLUSIONS: Our survey showed that the rate of symptomatic pediatric COVID-19 cases increased gradually, especially during the Omicron variant predominant period, and a certain percentage of pediatric cases had persistent symptoms. Certain percentages of pediatric COVID-19 patients had severe complications or prolonged symptoms. Further studies are needed to follow such patients.

Correlation between serum matrix metalloproteinase and antigenemia levels in patients infected with rotavirus.

Rotavirus (RV) antigenemia has been reported in patients with gastroenteritis; however, the exact mechanism remains unclear. In order to elucidate the mechanism of RV antigenemia, an association between RV antigenemia and matrix metalloproteinase (MMP) were analyzed. The object of this study was to elucidate the role of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in the pathogenesis of RV antigenemia. Forty children admitted to hospital with RV gastroenteritis were enrolled in this study. Paired serum samples were collected at the time of admission and discharge. Enzyme-linked immunosorbent assays (ELISA) were used to detect serum concentrations of viral antigens, MMP-1, -2, -9, -13, TIMP -1, and -2. Cytokines were measured using flow cytometric beads array. RV antigens were significantly higher in serum collected at the time of admission than discharge (P < 0.001). MMP-9 concentrations were significantly higher in serum collected at the time of admission than discharge (P < 0.001). MMP-2 concentrations were significantly lower in serum collected at the time of admission than discharge (P < 0.001). A weak but a significantly positive association (P = 0.034) was observed between RV antigen and MMP-9 in serum collected at the time of admission, and inverse association was observed between RV antigen and MMP-2. In addition, a weak but significantly positive association (P = 0.002) was observed between IL-6 and MMP-9. These data suggest that MMPs may contribute to the pathogenesis of RV antigenemia.

Clinical characteristics of norovirus gastroenteritis among hospitalized children in Japan.

Acute diarrhea is one of commonest pediatric illnesses worldwide. Although the importance of norovirus as a cause of gastroenteritis outbreaks is well documented, its role in sporadic acute gastroenteritis is not well characterized. The aim of this study was to clarify the prevalence and clinical characteristics of norovirus gastroenteritis among hospitalized children. Between November 2007 and April 2008, inpatients under 12 years of age with acute gastroenteritis in a single hospital in Japan were investigated. A stool sample from each patient was screened for enteropathogenic bacteria and tested by reverse transcription polymerase reaction for norovirus and by an immunochromatographic method for rotavirus and enteric adenoviruses. The clinical features of children with norovirus gastroenteritis were compared with those of children with rotavirus and children without noro- or rotovirus infections. Among 107 patients included in this study, norovirus and rotavirus were detected in 36 (34%) and 37 (35%) patients, respectively. Compared with rotavirus enteritis, the duration of vomiting and diarrhea was significantly longer, and serum C-reactive protein concentrations were higher, in patients with norovirus enteritis. Norovirus was detected as frequently as rotavirus in hospitalized pediatric gastroenteritis patients. Our results suggest that norovirus gastroenteritis among hospitalized young children is not less severe than rotavirus gastroenteritis.

SMTP (Stachybotrys microspora triprenyl phenol) enhances clot clearance in a pulmonary embolism model in rats.

BACKGROUND: Stachybotrys microspora triprenyl phenols (SMTPs) are a novel family of small molecules that enhance both activation and fibrin-binding of plasminogen. While their effects on fibrinolysis have been characterized in vitro, little is known about their activity in vivo with respect to plasminogen activation and blood clot clearance. RESULTS: To select a potent SMTP congener for the evaluation of its action in vitro and in vivo, we tested several SMTP congeners with distinct structural properties for their effects on plasminogen activation. As a result, SMTP-7 (orniplabin) was found to have distinguished activity. Several lines of biochemical evidence supported the idea that SMTP-7 acted as a plasminogen modulator. SMTP-7 elevated plasma level of plasmin-α2-antiplasmin complex, an index of plasmin formation in vivo, 1.5-fold in mice after the intravenous injections at doses of 5 and 10 mg kg-1. In a rat pulmonary embolism model, SMTP-7 (5 mg kg-1) enhanced the rate of clot clearance ~3-fold in the absence of exogenous plasminogen activator. Clot clearance was enhanced further by 5 mg kg-1 of SMTP-7 in combination with single-chain urokinase-type plasminogen activator. CONCLUSIONS: Our results show that SMTP-7 is a superior plasminogen modulator among the SMTP family compounds and suggest that the agent enhances plasmin generation in vivo, leading to clearance of thrombi in a model of pulmonary embolism.

Detection of Mycoplasma pneumoniae by loop-mediated isothermal amplification (LAMP) assay and serology in pediatric community-acquired pneumonia.

Rapid diagnosis of Mycoplasma pneumoniae pneumonia is required for treatment with effective antimicrobial agents without delay; however, this capacity has not yet been established in clinical practice. Recently, a novel nucleic acid amplification method termed loop-mediated isothermal amplification (LAMP) has been used to rapidly diagnose various infectious diseases. In this study, we prospectively evaluated the efficacy of the LAMP assay to rapidly diagnose M. pneumoniae pneumonia in clinical practice. Three hundred sixty-eight children (median age, 3.8 years; range, 0.1-14.3 years) admitted to our hospital between April 2009 and March 2010 for community-acquired pneumonia were enrolled in this study. We obtained throat swabs on admission to detect M. pneumoniae DNA and paired serum samples on admission and at discharge to assay M. pneumoniae antibody titers. M. pneumoniae pneumonia was diagnosed by either a positive LAMP assay or a fourfold or greater increase in antibody titer. Overall, 46 children (12.5% of the patients with pneumonia) were diagnosed with M. pneumoniae pneumonia; of these, 27 (58.7%) were aged less than 6 years. Of the aforementioned 46 children, 38 (82.6%) and 37 (80.4%) were identified by LAMP and serology, respectively. When the results of serology were taken as the standard, the sensitivity and specificity and positive and negative predictive values of the LAMP assay were 78.4%, 97.3%, 76.3%, and 97.6%, respectively. We concluded the LAMP assay may be useful for rapid diagnosis of M. pneumoniae pneumonia.

[A study for the necessity of virus titer of varicella vaccine presently used].

Recently available varicella vaccine titers are several dozen times higher than the formulation standard in accompanying information, i.e., > or = 1,000 PFU/dose. We investigated changes in immunogenicity associated with vaccination using a reduced dose whose virus titer was close to that used when the vaccine was developed, and examined the need for the virus titer presently used. In a non blinded study of 43 children with no history of varicella infection, we administered 0.1 mL of varicella vaccine (1/5 of the normal dose) to 20 children 1 year 0 month to 4 years 5 months old (median: 1 year 5 months) and the standard 0.5mL dose to 23 children 1 year 2 months to 3 years 7 months old (median: 1 year 9 months). We measured IAHA and gpELISA antibody titer before vaccination and 4 to 6 weeks after vaccination. We defined "positive" as > or = 2 fold of IAHA titer and > or = 50 U of gpELISA antibody titer. We administered an additional 0.5mL of varicella vaccine to children whose IAHA titer failed to show seroconversion and remeasured antibody titer 4 to 6 weeks after revaccination. IAHA seroconversion was 25.0% (5/20) and gpELISA seroconversion 55.0% (11/20) in the 0.1 mL vaccination group, which was lower than that of 76.2% (16/21) and 87.0% (20/23), IAHA p < 0.01, gpELISA p < 0.05, in the 0.5 mL vaccination group. We administered an additional vaccination to 19 children--15 in the 0.1 mL vaccination group and 4 in the 0.5 mL vaccination group-with 100% seroconversion for both methods. Mean antibody titer after revaccination in the 0.1 mL vaccination group (IAHA 2 (6.0), gpELISA 10 (3.7)) was higher than those in the 0.5mL vaccination group who seroconverted following initial vaccination (IAHA 2(4.5), gpELISA 10(2.6)) (p < 0.01). We also measured virus titer in the remaining vaccine following vaccination of 0.1 mL (n = 20), and estimated virus titer administered to the 0.1 mL vaccination group to be 2,600-6,400 PFU/ dose. Varicella vaccine immunogenicity decreased if dosage was reduced to 1/5 of the standard dose, indicating that the present virus titer is necessary to maintain adequate immunogenicity. An additional administration of the standard dose to children who failed to seroconvert after initial 0.1 mL administration produced high antibody titers thought to constitute a booster effect.

Clinical evaluation of a new rapid immunochromatographic test for detection of Bordetella pertussis antigen.

A more rapid and less complicated test to diagnose pertussis is required in clinical settings. We need to detect Bordetella pertussis, which mainly causes pertussis, as early as possible, because pertussis is more likely to become severe in infants, and people around them can easily become a source of infection due to its strong infectivity. Nevertheless, methods that can detect B. pertussis rapidly and efficiently are lacking. Therefore, we developed a new immunochromatographic antigen kit (ICkit) for the early diagnosis of pertussis. The ICkit detects B. pertussis antigens in a nasopharyngeal swab without equipment and provides the result in about 15 min with a simple procedure. Additionally, a prospective study to evaluate the ICkit was conducted in 11 medical institutions, involving 195 cases with suspected pertussis. Compared with the real-time polymerase chain reaction (rPCR), the sensitivity and specificity of the ICkit were 86.4% (19/22) and 97.1% (168/173), respectively. The ICkit detected the antigen in both children and adults. Furthermore, the ICkit detected the antigen until the 25th day from the onset of cough, when rPCR detected the antigen. Thus, the ICkit demonstrated a high correlation with rPCR and would help diagnose pertussis more rapidly and efficiently.