Analysis of cytokine levels, cytological findings, and MP-DNA level in bronchoalveolar lavage fluid of children with Mycoplasma pneumoniae pneumonia.

BACKGROUND: The present study was conducted to determine the inflammatory response in the lungs of children with Mycoplasma pneumoniae pneumonia (MPP). METHODS: This study retrospectively analyzed cytokine levels, cytological findings, and M. pneumoniae (MP)-DNA level in the bronchoalveolar lavage fluid (BALF) of 96 children with MPP. The study utilized Spearman's correlation method to evaluate the contribution of BALF and blood parameters in MPP children. RESULTS: (1) A total of 96 MPP children were classified into the Low MP-DNA MPP group (BALF MP-DNA ≤ 105 copies/mL) and the High MP-DNA MPP group (BALF MP-DNA > 105 copies/mL); the Non-fever MPP group (no fever during the entire course of pneumonia) and the Fever MPP group; the Defervescence MPP group (fever had subsided at the time of bronchoscopy) and the Fervescence MPP group; and the Mild MPP group and the Severe MPP group. (2) The High MP-DNA MPP, Fever MPP, Fervescence MPP, and Severe MPP groups had higher levels of interleukin (IL)-6, IL-10, and tumor necrosis factor-α (TNF-α) in their BALF (all p < .05). (3) The proportions of neutrophils and macrophages in the BALF of the High MP-DNA MPP and Fever MPP groups increased and decreased, respectively (all p < .05). (4) In the BALF of MPP children, MP-DNA, IL-6, IL-10, TNF-α, and interferon gamma (IFN-γ) levels positively correlated with neutrophil proportion while negatively correlated with macrophage proportion (all p < .05). (5) The MP-DNA, IL-6, IL-10, TNF-α, and IFN-γ levels in the BALF of MPP children were positively correlated with the levels of C-reactive protein, procalcitonin, lactic dehydrogenase, fibrinogen, and d-dimer, while they were negatively correlated with the albumin level (all p < .05). CONCLUSIONS: In children with MPP, the pulmonary inflammatory immune response was stronger in the High MP-DNA MPP, Fever MPP, Fervescence MPP, and Severe MPP groups. The relationship between pulmonary cytokine levels, MP-DNA load, and serum inflammatory parameters were found to be weak.

Respiratory Microbiome Profile of Pediatric Pulmonary Hypertension Patients Associated With Congenital Heart Disease.

BACKGROUND: Pulmonary hypertension (PH) associated with congenital heart disease (CHD) is the most common type of PH in pediatric patients. The airway microbiome profile in CHD-PH patients remains rarely studied. METHODS: A total of 158 children were recruited for collection of oropharyngeal swabs to sequence the 16S ribosomal RNA (16S rRNA) V3-V4 region of respiratory microbiome, to establish a correlation between these bacterial groups and echocardiography indicators in CHD-PH patients. RESULTS: Bacterial α- and ß-diversity of the airway microbiome indicated a significantly lower richness in the CHD-PH group and compositional differences associated with the specific taxa and their relative abundances in the upper respiratory tract. Principal coordinate analysis showed that the pharynx microbiota composition in the CHD-PH group varied from that in the CHD or control group. The linear discriminant analysis effect size also highlighted an increased presence of Streptococcus and Rothia in pediatric CHD-PH patients. Comparison of microbial composition between pediatric and adult PH patients showed significant differences and separation of microbiota. The correlation between bacterial abundance and transthoracic echocardiography indexes in CHD-associated PH indicated that different groups of microbiomes may be related to different PH grades. CONCLUSIONS: In summary, our study reported the systematic definition and divergent profile of the upper respiratory tract microbiota in pediatric PH patients, CHD and reference subjects, as well as between pediatric and adult PH patients.

ZEB1 recruits BRG1 to regulate airway remodelling epithelial-to-mesenchymal transition in asthma.

NEW FINDINGS: What is the central question of this study? The aim was to investigate the function of brahma-related gene-1 (BRG1) in airway remodelling epithelial-to-mesenchymal transition (EMT) of asthma and identify the transcription factor of BRG1 that binds to the protomer of E-cadherin. What is the main finding and its importance? This study highlighted an important molecular mechanism involving chromatin remodelling factor BRG1 that played a crucial role in airway remodelling EMT of asthma and demonstrated that ZEB1 was the key transcription factor recruiting BRG1. This finding might offer new insights into gene-based therapy for asthma. ABSTRACT: Epithelial-to-mesenchymal transition (EMT) of airway remodelling happens in children with asthma. A reduction in the epithelial marker E-cadherin is reported to be one of the initiating factors of EMT. Our previous study showed that chromatin remodelling factor brahma-related gene-1 (BRG1) could regulate the expression of E-cadherin indirectly. However, the transcription factor involved in the recruitment of BRG1 in asthma is unknown. Here, we studied the function of Brg1 in an ovalbumin-induced asthma model [lung-specific conditional Brg1 knockdown (Brg1-/- ) mice] and human bronchial epithelial 16HBE cells stably expressing BRG1 short hairpin RNA. Our results showed that Brg1 was involved in EMT in asthmatic mice by detecting the expression of EMT markers. We also identified that BRG1 participated in the transforming growth factor-ß-induced EMT of 16HBE cells. We observed that zinc finger E-box binding homeobox 1 (ZEB1) and BRG1 co-localized in the EMT of TGF-ß-induced 16HBE cells. Further results revealed that ZEB1 recruited BRG1 and bound to the promoter region (+3563/3715) to regulate E-cadherin expression. Thus, ZEB1 might be the key transcription factor to recruit BRG1 in airway remodelling EMT of asthma and might be a new therapeutic target.

The difference in clinical features and prognosis of severe adenoviral pneumonia in children of different ages.

This study aims to analyze the difference in clinical features and prognosis of severe adenovirus pneumonia (SAP) in children of different ages and analyze the risk factors for poor prognosis in children with SAP. A retrospective observational study was performed to describe the clinical features and analyze the risk factors for death and postinfectious bronchiolitis obliterans (PIBO) in 303 children hospitalized with SAP from January 2015 through to January 2020. The participants were divided into four age groups: <6 months (n = 25, 8.3%); 6-12 months (n = 98, 32.3%); 12-36 months (n = 118, 38.9%); and >36 months (n = 62, 20.5%). Fever rate, peak, and duration were the lowest in the <6 months group, while no significant difference was found among other age groups. Serum levels of lactate dehydrogenase and a load of adenovirus were the lowest in the <6 months group, and the highest in the 6-12 and 12-36 months groups, respectively. A total of 80.9% of patients recovered, 3.3% of patients died, and 15.8% of patients were diagnosed with PIBO. The mortality rate showed no significance between age groups. The >36 months group had the highest recovery rate and the lowest incidence of PIBO, while the 6-12 months group had the lowest recovery rate and the highest incidence of PIBO. Independent risk factors for PIBO among all participants from the four groups were invasive mechanical ventilation, administration of intravenous steroids, duration of fever, and male gender. Independent risk factors for death among all participants from the four groups were hypercapnia, low albumin levels, and invasive mechanical ventilation. Risk factor analysis of different ages was not possible due to the limited sample size. The morbidity, clinical features, and prognosis of SAP are affected by children's ages. Pediatric patients with a longer duration of fever, hypercapnia, low serum albumin levels, invasive mechanical ventilation, and intravenous steroids use are more likely to develop a poor prognosis in SAP, especially if the patient is male.

Consistency between nasopharyngeal aspirates and bronchoalveolar lavage fluid in pathogen detection in children with pneumonia: an analysis of 533 cases. / 533ä¾‹è‚ºç‚Žå„¿ç«¥é¼»å’½æŠ½å¸ç‰©å’Œæ”¯æ°”ç®¡è‚ºæ³¡çŒæ´—æ¶²çš„ç— åŽŸæ£€å‡ºä¸€è‡´æ€§åˆ†æž.

OBJECTIVES: To study the consistency between nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in pathogen detection in children with pneumonia. METHODS: A retrospective analysis was performed on the data of pathogens detected in 533 children with pneumonia from February 2017 to March 2020. The paired McNemar's test was used to compare the difference in pathogen detection between NPA and BALF groups. The Kappa coefficient was used to analyze the consistency in pathogen detection between the two groups. RESULTS: NPA had a sensitivity of 28%, a specificity of 74%, a positive predictive value of 14%, and a negative predictive value of 91% in detecting bacteria, and a Kappa coefficient of 0.013 suggested poor consistency between NPA and BALF. NPA had a sensitivity of 52%, a specificity of 81%, a positive predictive value of 24%, and a negative predictive value of 94% in detecting viruses, and a Kappa coefficient of 0.213 suggested poor consistency between NPA and BALF. NPA had a sensitivity of 78%, a specificity of 71%, a positive predictive value of 49%, and a negative predictive value of 90% in detecting Mycoplasma pneumoniae, and a Kappa coefficient of 0.407 suggested moderate consistency between NPA and BALF. CONCLUSIONS: There is poor consistency between NPA and BALF in the detection of bacteria and viruses, and clinicians should be cautious in diagnosing lower respiratory tract infection based on bacteria or viruses detected in NPA. There is moderate consistency between NPA and BALF in the detection of Mycoplasma pneumoniae, suggesting that it may be reliable to diagnose lower respiratory tract infection based on Mycoplasma pneumoniae detected in NPA, while comprehensive judgment in combination with clinical conditions is needed.

Blockade of GITRL/GITR signaling pathway attenuates house dust mite-induced allergic asthma in mice through inhibition of MAPKs and NF-κB signaling.

GITRL/GITR signaling pathway plays an important role in allergy, inflammation, transplantation and autoimmunity. However, its role in asthma remains unclear. Thus, the present study aimed to investigate changes in this pathway and observe the therapeutic effect of its blocking on asthma. By using house dust mite-induced asthma model, changes of GITRL/GITR and its downstream molecules MAPKs (e.g., p38 MAPK, JNK and Erk) and NF-κB were observed. After that, GITRL in lung of mice was knocked down by recombinant adeno-associated virus to observe the impact on its downstream molecules and assess the therapeutic effect on asthma. These results showed that GITRL/GITR and its downstream molecules MAPKs/NF-κB were activated in asthmatic mice. This activation was suppressed after GITRL knockdown, and allergic airway inflammation and airway hyperresponsiveness were alleviated. These results demonstrate that GITRL/GITR-MAPKs/NF-κB signaling pathway participates in the pathogenesis of asthma. Blockade of GITRL/GITR signaling pathway exhibits protective effects in a mouse model of house dust mite-induced allergic asthma.

GITRL on dendritic cells aggravates house dust mite-induced airway inflammation and airway hyperresponsiveness by modulating CD4+ T cell differentiation.

BACKGROUND: Glucocorticoid-induced tumor necrosis factor receptor family-related protein ligand (GITRL) plays an important role in tumors, autoimmunity and inflammation. However, GITRL is not known to modulate the pathogenesis of allergic asthma. In this study, we investigated whether regulating GITRL expressed on dendritic cells (DCs) can prevent asthma and to elucidate its mechanism of action. METHODS: In vivo, the role of GITRL in modulating house dust mite (HDM)-induced asthma was assessed in adeno-associated virus (AAV)-shGITRL mice. In vitro, the role of GITRL expression by DCs was evaluated in LV-shGITRL bone marrow dendritic cells (BMDCs) under HDM stimulation. And the direct effect of GITRL was observed by stimulating splenocytes with GITRL protein. The effect of regulating GITRL on CD4+ T cell differentiation was detected. Further, GITRL mRNA in the peripheral blood of asthmatic children was tested. RESULTS: GITRL was significantly increased in HDM-challenged mice. In GITRL knockdown mice, allergen-induced airway inflammation, serum total IgE levels and airway hyperresponsiveness (AHR) were reduced. In vitro, GITRL expression on BMDCs was increased after HDM stimulation. Further, knocking down GITRL on DCs partially restored the balance of Th1/Th2 and Th17/Treg cells. Moreover, GITRL stimulation in vitro inhibited Treg cell differentiation and promoted Th2 and Th17 cell differentiation. Similarly, GITRL mRNA expression was increased in the peripheral blood from asthmatic children. CONCLUSIONS: This study identified a novel role for GITRL expressed by DCs as a positive regulator of CD4+ T cells responses in asthma, which implicates that GITRL inhibitors may be a potential immunotherapy for asthma.

A multicenter survey of pediatric flexible bronchoscopy in western China.

BACKGROUND: This study aims to investigate the current use of pediatric flexible bronchoscopy (PFB) in western China. METHODS: A cross-sectional survey was conducted in western China between January 1, 2018 to December 30, 2018. Fifty-four centers were invited to answer a questionnaire for seeking information about performance of PFB. The data collected were analyzed to investigate the current status of western China, and hierarchical cluster analysis was conducted to identify developmental level of PFB of cities. RESULTS: Forty-seven centers were included in analysis. A total of 22,585 flexible bronchoscopies were carried out in the participating centers from January 1, 2018 to December 30, 2018. Eight centers (17.0%) performed more than 1,000 pediatric flexible bronchoscopies for children, but 20 centers (42.6%) performed less than 100. The median proportion of systematic and professional trained physicians in a single team was 50%, and the pooled rate was 59% (95% CI, 47-70%). Only 10, 8 and 11 centers performed balloon dilatation, thermal ablation and cryoablation, respectively. Obvious cough was the most frequent complication after the PFB procedure, the pooled rate is 24% (95% CI, 18-29%). No one died during and after the PFB procedure. Hierarchical cluster analysis showed that the development of PBF in western China varies, and Chongqing might be the most developed area in PFB use in western China. CONCLUSIONS: Flexible bronchoscopy in children is now a mature and safe procedure, while the development of PFB varies in western China, especially for the advanced bronchoscopic intervention.

[Epidemiological characteristics of respiratory syncytial virus in hospitalized children with acute lower respiratory tract infection in Chongqing, China, from 2013 to 2018: an analysis of 2 066 cases].

OBJECTIVE: To study the detection rate, epidemic pattern, and clinical features of respiratory syncytial virus (RSV) in hospitalized children with acute lower respiratory infection (ALRI). METHODS: Nasopharyngeal aspirates were collected from children with ALRI, aged < 2 years, who were hospitalized in Children's Hospital of Chongqing Medical University from June 2013 to May 2018. Multiplex PCR was used to detect 16 common respiratory viruses. The epidemiological characteristics of RSV were analyzed. RESULTS: A total of 2 066 hospitalized children with ALRI were enrolled. Among the children, 1 595 (77.20%) tested positive for virus and 826 (39.98%) tested positive for RSV [410(49.6%) positive for RSV-A, 414 (50.1%) positive for RSV-B, and 2 (0.2%) positive for both RSV-A and RSV-B]. RSV-B was the main subtype detected in 2013-2014 and 2016-2017, while RSV-A was the main subtype in 2014-2015 and 2017-2018, and these two subtypes were prevalent in 2015-2016. The highest detection rate of RSV was noted in winter. RSV + human rhinovirus was the most common combination of viruses and was detected in 123 children. These children were more likely to develop wheezing than those with single RSV detected (P=0.030). A total of 298 samples were detected with single RSV, 148 were detected with RSV mixed with other viruses, 389 were detected with other viruses, and 241 were detected negative for viruses. Compared with the other viruses and negative virus groups, the single RSV group had a significantly younger age and significantly higher incidence rates of dyspnea, respiratory failure, and severe lower respiratory tract infection (P < 0.0083). The RSV-A positive group had a significantly higher proportion of boys than the RSV-B positive group (P=0.004), but there were no significant differences in clinical manifestations between the two groups. CONCLUSIONS: In Chongqing in 2013-2018, RSV-A and RSV-B not only can predominate alternately, but also can co-circulate during a season. RSV is the major viral pathogen of hospitalized children with ALRI and can cause severe lower respiratory tract infection. There are no differences in clinical manifestations between children with RSV-A infection and those with RSV-B infection, but boys are more susceptible to RSV-A infection.

How should our testing behaviour change with time in children in current COVID-19 pandemic?

BACKGROUNDS: More paediatric-confirmed cases have been reported with the global pandemic of COVID-19. This study aims to summarize the key points and supply suggestions on screening paediatric COVID-19 patients more appropriately. MATERIALS AND METHODS: We retrospectively included paediatric patients who have accepted SARS-CoV-2 RT-PCR testing in Children's Hospital of Chongqing Medical University (30 January 2020 to 13 February 2020) and compared them with paediatric-confirmed COVID-19 cases. Besides, a review was carried out by analysing all current literature about laboratory-confirmed paediatric cases with COVID-19. RESULTS: There were 46 suspected cases included in the descriptive study. The results of SARS-CoV-2 RT-PCR testing were all negative. Compared with paediatric-confirmed cases, the incidence of epidemic history was lower in suspected cases (P < .001). The rate of fever (P < .001), cough (P < .001), headache or dizziness (P < .001), vomiting (P < .001) and abdominal discomfort or distention (P = .01) were more observed in the included suspected children. There were more children having decreased WBC count in the confirmed group. In the literature review, twenty-nine studies were obtained with 488 paediatric COVID-19 cases. 88.6% of them had epidemiological history. Cough and fever were the most common symptoms. Compared with older patients, the incidence of fever, respiratory symptoms, lethargy and headache or dizziness was lower, while gastrointestinal symptoms were reported more. CONCLUSIONS: Children with a history of close contact with confirmed cases, manifested as cough and fever should be paid more attention to after excluding infection of other common pathogens. Atypical symptoms should not be over-emphasized in screening paediatric COVID-19. More studies are needed for guiding efficient recognition in paediatric COVID-19.

Potential effectiveness and safety of antiviral agents in children with coronavirus disease 2019: a rapid review and meta-analysis.

BACKGROUND: The COVID-19 outbreak presents a new, life-threatening disease. Our aim was to assess the potential effectiveness and safety of antiviral agents for COVID-19 in children. METHODS: Electronic databases (MEDLINE, Embase, Web of Science, the Cochrane library, CBM, CNKI, and Wanfang Data) from their inception to March 31, 2020 were searched for randomized controlled trials (RCTs), clinical controlled trials and cohort studies of interventions with antiviral agents for children (less than 18 years of age) with COVID-19. RESULTS: A total of 23 studies with 6,008 patients were included. There was no direct evidence and all of evidence were indirect. The risks of bias in all studies were moderate to high in general. The effectiveness and safety of antiviral agents for children with COVID-19 is uncertain: For adults with COVID-19, lopinavir/ritonavir had no effect on mortality [risk ratio (RR) =0.77; 95% confidence interval (CI), 0.45 to 1.30]. Arbidol and hydroxychloroquine (HCQ) had no benefit on probability of negative PCR test (RR =1.27; 95% CI, 0.93 to 1.73; RR =0.93; 95% CI, 0.73 to 1.18) respectively. For adults with SARS, interferon was associated with reduced corticosteroid dose [weighted mean difference (WMD) = -0.14 g; 95% CI, -0.21 to -0.07] but had no effect on mortality (RR =0.72; 95% CI, 0.28 to 1.88); ribavirin did not reduce mortality (RR =0.68; 95% CI, 0.43 to 1.06) and was associated with high risk of severe adverse reactions; and oseltamivir had no effect on mortality (RR =0.87; 95% CI, 0.55 to 1.38). Ribavirin combined with interferon was also not effective in adults with MERS and associated with adverse reactions. CONCLUSIONS: There is no evidence showing the effectiveness of antiviral agents for children with COVID-19, and the clinical efficacy of existing antiviral agents is still uncertain. We do not suggest clinical routine use of antivirals for COVID-19 in children, with the exception of clinical trials.

Effectiveness of fractional exhaled nitric oxide for asthma management in children: A systematic review and meta-analysis.

BACKGROUND: Fractional exhaled nitric oxide (FENO) is a noninvasive strategy for diagnosing and managing asthma, but limited evidence is available for the effects of FENO-guided asthma management in children. This meta-analysis aimed to evaluate the effectiveness of FENO for asthma management in children. METHODS: In total, six databases were searched, and 23 randomized controlled trials that compared the effects of FENO-guided asthma management with those not using FENO in pediatric asthma were included. Methodological quality was assessed using the Cochrane risk-of-bias tool. Data for relevant endpoints were extracted and analyzed. RESULTS: Our meta-analysis of the effectiveness of FENO for asthma management in children showed that FENO-guided asthma management helped reduce the numbers of children with asthma exacerbations (risk ratio: 0.73; 95% confidence interval [CI:] 0.63-0.84; P < .0001) and the exacerbation frequency (standardized mean difference: -1.57; 95% CI: -2.25 to -0.88; P < .00001). Furthermore, it improved the predicted forced expiratory volume in 1 minute (weighted mean difference [WMD]: 3.67; 95% CI: 0.91-6.43; P = .009) and was also found to be associated with an increase of daily inhaled corticosteroid (ICS) dose (WMD: 64.17 µg; 95% CI: 53.59-74.75; P < .00001). CONCLUSIONS: This meta-analysis indicated that the FENO-guided asthma management strategy could partially improve the outcomes of pediatric asthma at the expense of increased ICS use.

Allogeneic human umbilical cord-derived mesenchymal stem cells for severe bronchopulmonary dysplasia in children: study protocol for a randomized controlled trial (MSC-BPD trial).

BACKGROUND: Bronchopulmonary dysplasia (BPD) is a complex lung pathological lesion secondary to multiple factors and one of the most common chronic lung diseases. It has a poor prognosis, especially in preterm infants. However, effective therapies for this disease are lacking. Stem-cell therapy is a promising way to improve lung injury and abnormal alveolarization, and the human umbilical cord (hUC) is a good source of mesenchymal stem cells (MSCs), which have demonstrated efficacy in other diseases. We hypothesized that intravenously administered allogeneic hUC-MSCs are safe and effective for severe BPD. METHODS: The MSC-BPD trial is a randomized, single-center, open-label, dose-escalation, phase-II trial designed to investigate the safety and efficacy of hUC-MSCs in children with severe BPD. In this study, 72 patients will be enrolled and randomly divided into two intervention groups and one control group. Patients in the intervention groups will receive a low dose of hUC-MSCs (n = 24; 2.5 million cells/kg) or a high dose of hUC-MSCs (n = 24; 5 million cells/kg) in combination with traditional supportive treatments for BPD. The patients in the control group (n = 24) will be treated with traditional supportive treatments alone without hUC-MSCs. The primary outcome measures will be cumulative duration of oxygen therapy. Follow-up assessments will be performed at 1, 3, 6, 12, and 24 months post intervention, and the key outcome during follow-up will be changes on chest radiography. Statistical analyses will evaluate the efficacy of the hUC-MSC treatment. DISCUSSION: This will be the first randomized controlled trial to evaluate the safety and efficacy of intravenously administered hUC-MSCs in children with severe BPD. Its results should provide a new evidence-based therapy for severe BPD. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03601416. Registered on 26 July 2018.

Correction: Pseudomonas aeruginosa-derived exosomes ameliorates allergic reactions via inducing the Treg response in asthma.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

[Diffuse alveolar hemorrhage in children].

Diffuse alveolar hemorrhage (DAH) is a clinical syndrome with major clinical manifestations of hemoptysis, anemia, and diffuse infiltration in the lung. DAH has a high mortality rate in the acute stage and is a life-threatening emergency in clinical practice. Compared with adult DHA, childhood DHA tends to have a specific spectrum of underlying diseases. It has long been believed that idiopathic pulmonary hemosiderosis (IPH) is the main cause of childhood DAH; however, with the increase in reports of childhood DAH cases, the etiology spectrum of childhood DAH is expanding. The treatment and prognosis of DAH with different etiologies are different. This review article gives a general outline of childhood DAH, with focuses on DAH caused by IPH, systemic lupus erythematosus, anti-neutrophil cytoplasmic antibody-related vasculitis, COPA syndrome, or IgA vasculitis.

Severe Bordetella pertussis infection and vaccine issue in Chongqing, from 2012 to 2018.

OBJECTIVE: Pertussis is a highly contagious respiratory illness mainly caused by the Gram-negative bacterium Bordetella pertussis. The infection of B. pertussis has been increasing and the current diagnosis of pertussis in children is challenging; little is known of B. pertussis infection in Chongqing. METHODS: There were 25,441 children (14,863 male and 10,578 female) with suspected pertussis enrolled in our retrospective study from December 2012 to November 2018. Then 800 children with suspected B. pertussis infection were randomly chosen to be evaluated by simultaneous amplification and testing in this prospective study. RESULTS: Infants younger than 12 months had the greatest burden of pertussis, and the incidence of pertussis in Chongqing appeared to have a periodic pattern. The problem of vaccine quality in China was more serious than previously reported based on the fluctuation of infection rates from 2012 to 2018. Simultaneous amplification and testing to detect B. pertussis RNA (Area Under Curve: 0.900 and Kappa value: 0.831) had better diagnostic performance than real-time PCR for B. pertussis DNA (Area Under Curve: 0.869 and Kappa value: 0.690). CONCLUSIONS: We revealed the characteristics of B. pertussis infection and vaccine issues in Chongqing. Simultaneous amplification and testing could be a potential novel assay for measuring B. pertussis infection in the future.

Pseudomonas aeruginosa-derived exosomes ameliorates allergic reactions via inducing the Treg response in asthma.

BACKGROUND: Exosomes are nanovesicles originating from multivesicular bodies that have complex functions and significant therapeutic effects in many diseases. In the present study, we successfully extracted exosomes from Pseudomonas aeruginosa and assessed the effect of those exosomes on the development of the allergic response in two types of classic asthma models. METHODS: Female BALB/c mice were administrated with P. aeruginosa-derived exosomes 1 week before ovalbumin (OVA) or house dust mite (HDM) sensitization. Bronchoalveolar lavage fluid, serums and lung tissues were collected and analyzed for pathophysiology and immune responses. RESULTS: Our results demonstrated that P. aeruginosa-derived exosomes inhibited the development of airway hyper-responsiveness (AHR), peribronchial and perivascular inflammation in lung tissues and the level of serum IgE. Moreover, this protective effect was associated with an increase in the regulatory T cell (Treg) response and a concomitant decreased Th2 response. CONCLUSIONS: In conclusion, these observations demonstrated that P. aeruginosa-derived exosomes could induce protection against allergic sensitization in asthma mice, and our study provided a new insight to prevent allergic diseases.

LPS Exposure in Early Life Protects Against Mucus Hypersecretion in Ovalbumin-Induced Asthma by Down-Regulation of the IL-13 and JAK-STAT6 Pathways.

BACKGROUND/AIMS: Previous studies have shown that lipopolysaccharide (LPS) exposure may have a protective effect on asthma by reducing airway hyper-responsiveness, airway inflammation and serum IgE levels. However, there are few studies investigating the effect of LPS on mucous secretion in asthma. In this study, we evaluate the relationship between LPS pre-treatment in infant mice and airway mucus hypersecretion in an OVA (ovalbumin)-induced asthma model, and further explore the mechanisms behind this effect. METHODS: Mice were pre-treated with LPS by intranasal instillation (i.n.) from the 3rd day of life for 10 consecutive days before the OVA-induced asthma model was established. In order to detect mucus secretion, periodic acid-Schiff (PAS) staining was carried out, and the expression of Muc5ac was detected. The IL-13 levels in Bronchoalveolar lavage fluid (BALF) and lung tissue were also detected. In vitro, the expression of Muc5ac mRNA and protein was quantified in IL-13-stimulated 16HBE cells with or without LPS pre-treatment. In addition, proteins in the JAK2/STAT6 pathway, transcription factors (forkhead box transcription factor A2 (FOXA2), activation protein-1(AP-1), NF-κB), and the levels of reactive oxygen species (ROS) were also measured in vivo and in vitro. RESULTS: LPS pre-treatment reduced mucus secretion, as demonstrated by decreased PAS staining and muc5ac expression. Further exploration of the underlying mechanisms of this phenomenon revealed that LPS pre-treatment decreased the production of IL-13, IL-13 induced ROS synthesis was reduced, and the JAK2/STAT6 pathway was inhibited. Decreased stat6 increased transcription factor FOXA2, and the relatively increased FOXA2 further decreased the level of Muc5ac and mucous hypersecretion in OVA-induced asthma. CONCLUSIONS: LPS pre-treatment ameliorated mucus hypersecretion in an OVA-induced asthma model by inhibition of IL-13 production and by further inhibiting the JAK2/STAT6 pathway and ROS activity, and up-regulating expression of FOXA2.

[Effect of vitamin A as an adjuvant therapy for pneumonia in children: a Meta analysis].

OBJECTIVE: To investigate the effect and safety of vitamin A supplementation in children with pneumonia through a systematic review. METHODS: Cochrane Library, EMbase, PubMed, China Biology Medicine disc, CNKI, and Wanfang Data were searched for randomized controlled trials (RCTs) on vitamin A as an adjuvant therapy for pneumonia in children. Two reviewers independently screened the studies and evaluated their quality according to the inclusion and exclusion criteria. RevMan5.3 was used for the Meta analysis. RESULTS: A total of 15 RCTs with 3 021 patients were included. The Meta analysis showed that vitamin A supplementation did not reduce the mortality of children with pneumonia (P>0.05), but it increased the overall clinical response rate (P<0.05) and shortened the duration of pyrexia and cough, clearance time of signs and abnormal chest X-ray results, and length of hospital stay (P<0.05). As an adjuvant therapy, vitamin A did not increase the incidence rates of adverse reactions such as nausea, vomiting, diarrhea, allergy, and bregma bulging. CONCLUSIONS: Current evidence shows that in the treatment of pneumonia in children, vitamin A supplementation helps to relieve clinical symptoms and signs and shorten the length of hospital stay.The adjuvant therapy does not increase the incidence rates of adverse reactions.