The predictive values of soluble B7-DC in children with refractory mycoplasma pneumoniae pneumonia.

Background: Refractory mycoplasma pneumoniae pneumonia (RMPP) is a serious mycoplasma pneumoniae infection and is difficult to diagnose early. The levels of serum soluble B7-dendritic cell (sB7-DC) in children with mycoplasma pneumoniae pneumonia (MPP) were assessed to explore the clinical significance of sB7-DC levels in RMPP. Methods: A total of 65 patients with mycoplasma pneumoniae pneumonia (MPP) were enrolled in this study between January 2017 and December 2018. The patients were divided into the general mycoplasma pneumoniae pneumonia (GMPP) (n=30) and RMPP groups (n=35); the data of 20 normal children served as a control group (n=20). An enzyme-linked immunoassay kit was used to detect the expression of soluble B7-dendritic cell (sB7-DC) and other inflammatory factors. Binary logistic regression was performed to identify the independent predictors of RMPP. Receiver operating characteristic (ROC) curves were drawn to evaluate the value of each independent risk factor in the early diagnosis of RMPP. Results: The results showed that compared to the GMPP group, children in the RMPP group had a significantly longer hospital stay and had a significantly longer fever duration (P<0.05). The values of interferon-gamma (IFN-γ), interleukin 17 (IL-17), and sB7-DC in the RMPP group were significantly higher than those in the normal control and GMPP groups (all P<0.05). The results of the correlation analysis showed that sB7-DC was positively correlated with IFN-γ and IL-17 and these indicators could be used in combination to evaluate the severity of the disease. The binary logistic regression analysis identified IL-17 and sB7-DC as independent risk factors for RMPP (P<0.05). The ROC curve analysis showed that the cut-off values of IL-17 and sB7-DC were 309.6 pg/L and 1,109.7 pg/mL, respectively. The areas under the curve (AUCs) of IL-17 and sB7-DC were 0.741 and 0.794, respectively. The sensitivity of IL-17 to RMPP prediction was 83.3%, and the specificity was 62.9%. The sensitivity and specificity of sB7-DC to RMPP were 86.7% and 62.9%, indicating that sB7-DC had the highest predictive power for RMPP. Conclusions: The level of serum sB7-DC may play an important role in the early diagnosis of RMPP. Our research results provide a theoretical basis for the early diagnosis of RMPP.

[Association of Haemophilus influenzae infection with environmental and climatic factors in Suzhou, China]. / è‹å·žåœ°åŒºæµæ„Ÿå—œè¡€æ†èŒæ„ŸæŸ“ä¸ŽçŽ¯å¢ƒæ°”å€™çš„ç›¸å ³å› ç´ åˆ†æž.

OBJECTIVES: To investigate the epidemiological characteristics of respiratory Haemophilus influenzae (HI) infection in children in Suzhou, China and its association with climatic factors and air pollutants. METHODS: The data on air pollutants and climatic factors in Suzhou from January 2016 to December 2019 were collected. Respiratory secretions were collected from 7 940 children with acute respiratory infection who were hospitalized during this period, and bacterial culture results were analyzed for the detection of HI. A stepwise regression analysis was used to investigate the association of HI detection rate with air pollutants (PM2.5, PM10, NO2, SO2, CO, and O3) and climatic factors (monthly mean temperature, monthly mean humidity, monthly total rainfall, monthly total sunshine duration, and monthly mean wind speed). RESULTS: In 2016-2019, the 4-year overall detection rate of HI was 9.26% (735/7 940) among the children in Suzhou. The children aged <1 year and 1-<3 years had a significantly higher HI detection rate than those aged ≥3 years (P<0.01). The detection rate of HI in spring was significantly higher than that in the other three seasons, and the detection rate of HI in autumn was significantly lower than that in the other three seasons (P<0.001). The multiple linear regression analysis showed that PM10 and monthly mean wind speed were independent risk factors for the detection rate of HI: the detection rate of HI was increased by 0.86% for every 10 µg/m3 increase in the concentration of PM10 and was increased by 5.64% for every 1 m/s increase in monthly mean wind speed. Air pollutants and climatic factors had a lag effect on the detection rate of HI. CONCLUSIONS: HI is an important pathogen for acute respiratory infection in children in Suzhou and is prevalent in spring. PM10 and monthly mean wind speed are independent risk factors for the detection rate of HI.

The expression and function of programmed death-ligand 1 and related cytokines in neutrophilic asthma.

BACKGROUND: Programmed death-ligand 1 (PD-L1) is an important immune checkpoint inhibitor. Recent studies suggest that the PD-L1-mediated pathway may be a promising target in allergic asthma. However, the mechanism by which PD-L1 represses neutrophilic asthma (NA) remains unclear. In this study, we examined correlations between the expression of PD-L1 and the production of T helper cell type 1 (Th1), T helper cell type 2 (Th2), and T helper cell type 17 (Th17) cells in pediatric patients with NA and a mouse model. METHODS: The clinical samples of 26 children with asthma and 15 children with a bronchial foreign body were collected over a period of 12 months by the Children's Hospital of Soochow University. An experimental mouse model of asthma was established to study NA. An enzyme-linked immunoassay (ELISA) was used to assess soluble PD-L1 (sPD-L1) and cytokines [e.g., interleukin (IL)-4, IL-6, interferon gamma (IFN-γ), IL-17 and granulocyte-macrophage colony-stimulating factor (GM-CSF)] in bronchoalveolar lavage fluid (BALF). RESULTS: NA patients had significantly higher levels of sPD-L1, IL-6, IL-17, and GM-CSF in their BALF than non-NA and control patients (P<0.05). In a murine model of asthma, the positive rate and fluorescence intensity of PD-L1 in the NA group and the immunoglobulin G (IgG)-treated NA group were higher than in the PD-L1 antibody (Ab)-treated NA group and the phosphate-buffered saline (PBS) control group (P<0.05). In the plasma and the BALF of the NA group and the IgG-treatment NA group, the levels of IL-17, IL-4, tumor necrosis factor alpha (TNF-α), and granulocyte colony-stimulating were higher than those in the PBS control group (P<0.05). The histopathological examination of lung tissues from all mice groups showed that a large number of inflammatory cells were found around the airway in the NA group and the IgG-treatment group. CONCLUSIONS: PD-L1 may contribute to the Th17/IL-17 immune response, which is associated with neutrophilic inflammation and asthma. A PD-L1 blockade reduces pulmonary neutrophils and mucus production.

The diagnostic value of serological tests and real-time polymerase chain reaction in children with acute Mycoplasma pneumoniae infection.

BACKGROUND: This study set out to evaluate the clinical significance and diagnostic effectiveness of serological tests and real-time polymerase chain reactions (RT-PCR) in children of different age groups and disease durations infected with Mycoplasma pneumoniae (MP). METHODS: Pediatric patients with lower respiratory tract infection (LRTI) confirmed by polymerase chain reaction (PCR) were enrolled and subjected to bronchoalveolar lavage fluid PCR (BALF-PCR) for MP infection. The diagnostic values of the serum immunoglobulin M (IgM) test, paired sera immunoglobulin G (IgG) test, RT PCR applied to nasopharyngeal aspirates (NPA-PCR), and combined IgM and NPA-PCR test were evaluated. RESULTS: When BALF PCR was used as the gold standard, the MP positivity rate of combined IgM and NPA PCR was 78.85%in children aged 3-5 years. The positivity rates of IgM, NPA PCR, and combined IgM and NPA PCR in children older than 5 years were 71.21%, 72.72%, and 84.85%, respectively. The detection rate of combined IgM and NPA PCR was consistent with BALF PCR (Kappa =0.727). The MP positivity rates of combined IgM and NPA PCR at 1-2 weeks was as high as 91.11%, and was consistent with the BALF PCR (Kappa =0.756). Moreover, the positivity rates of IgM or NPA PCR at 2-3 weeks were 63.16%, and were consistent with each other (Kappa =0.771). CONCLUSIONS: Combined IgM and NPA PCR is the optimal test to confirm MP infection among children aged 3-5 years in cases with a disease duration of less than2 weeks, and either NPA PCR or IgM is recommended for children older than 5 years with a disease duration of 2-3 weeks. KEYWORDS: Mycoplasma pneumoniae pneumonia (MPP); diagnosis; children; age; disease duration.

[Detection of viral pathogens and allergens in infants and young children at high risk of asthma during a wheezing episode].

OBJECTIVE: To investigate the viral etiology and allergen distribution in infants and young children at high risk of asthma during a wheezing episode. METHODS: A total of 135 infants and young children at high risk of asthma were enrolled who were admitted due to asthmatic bronchitis or asthmatic bronchopneumonia between April 2016 and August 2017. Fluorescent probe PCR was used to measure influenza A (Flu A), respiratory syncytium virus (RSV), adenovirus (ADV), parainfluenza virus (PinF), human rhinovirus (HRV), human partial lung virus (hMPV) and human bocavirus (HBoV) in nasopharyngeal aspirates. ImmunoCAP was used to measure inhaled allergens, food allergens, and total IgE concentration. RESULTS: Among the 135 patients, the overall virus detection rate of nasopharyngeal aspirates was 49.6%, and HRV had the highest detection rate of 25.2%, followed by HBoV (9.6%), RSV (8.1%), PinF (5.9%), Flu-A (3.7%), ADV (1.5%) and hMPV (0.7%). The 1-3 years group had a significantly higher detection rate of HRV than the <1 year group (P<0.05). The positive rate of allergen screening was 59.3%, with 44% for inhaled allergens and 89% for food allergens. Among the inhaled allergens, dust mites had the highest positive rate of 77%, followed by mould (37%), pollen (26%) and animal dander (9%). Among the food allergens, egg white had a positive rate of 73% and milk had a positive rate of 68%. The <1 year group had a significantly higher positive rate of inhaled allergens than the 1-3 years group (P<0.05). The 1-3 years age group had a significantly higher level of T-IgE than the <1 year group (P<0.05). The positive virus group had a significantly higher positive rate of inhaled allergens than the non-virus group (P<0.05). The children with the second wheezing episode had significantly higher positive rates of inhaled allergens and food allergens and level of T-IgE than those with the first wheezing episode (P<0.05). The children with the second wheezing episode also had significantly higher positive rates of dust mites and mould than those with the first wheezing episode (P<0.05). CONCLUSIONS: Early HRV infection and inhaled allergen sensitization are closely associated with the development of wheezing in infants and young children at high risk of asthma.

The role of miR-29c/B7-H3/Th17 axis in children with Mycoplasma pneumoniae pneumonia.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired pneumonia in children. Recent studies demonstrated that the incidence of severe or fatal M. pneumoniae was gradually increasing, which may be related to the excessive inflammation. However, the exact pathogenesis of excessive inflammation in Mycoplasma pneumoniae pneumonia(MPP) is still unclear. This study aimed to reveal the role of miR-29c/B7-H3/Th17 axis in children with MPP. METHODS: Children hospitalized in Respiratory Department during Jan. 2014 to Dec. 2015 were enrolled. All children enrolled was confirmed with MP infection using real-time PCR and ELISA. Children were excluded if they were co-infected with other pathogens. A total of 52 children with MPP and 26 controls were enrolled. miR-29c expression in monocytes of children with MPP was determined by real-time PCR and soluble B7-H3 (sB7-H3) and IL-17 were determined by ELISA, and explore their clinical significance. miR-29c overexpression and silencing technology and luciferase reporter assay were performed to confirm whether B7-H3 is the direct target of miR-29c. The levels of transcription factor ROR-γt in CD4+ T cells and cytokine IL-17A in supernatant were detected after stimulated by different concentrations of B7-H3 fusion protein in vitro. RESULTS: Of all 52 children with MPP, the mean age of the children were 77 ± 33 months, and 23 cases were male accounting for 44.2%. Nineteen cases had pleural effusion accounting for 36.5%. Children with MPP had significantly lower level of miR-29c and higher level of sB7-H3 and IL-17 compared to controls (both P < 0.05). The level of miR-29c significantly increased during convalescent phase compared to that of acute phase while sB7-H3 and IL-17 significantly decreased during convalescent phase (both P < 0.05). There was a positive correlation between the level of sB7-H3 and IL-17 in children with MPP during acute-stage (r = 0.361,P = 0.009). Children with MPP combined with pleural effusion had significantly higher level of sB7-H3 compared to those without pleural effusion (9952.3 ± 3065.3 vs. 7449.7 ± 2231.5, pg/ml), and the levels of sB7-H3 was positively correlated with the number of days of fever. The level of miR-29c was negatively correlated with M. pneumoniae specific IgG, IgM level. High concentrations of B7-H3(15µg/ml) could enhance ROR-γt expression and increase IL-17A. Functional studies based on luciferase reporter assay and immunofluorescence staining suggested that B7-H3 is the direct target of miR-29c, and miR-29c silencing or overexpression could up- or down-regulate the expression of B7-H3 in THP-1 cells. CONCLUSIONS: The axis of miR-29c/B7-H3/Th17 plays a vital role in children with MPP through excessive inflammation. miR-29c and B7-H3 may be the new target for the prevention and treatment of MPP, and may be the novel and potential biomarkers for the assessment of prognosis.

[Epidemiological analysis of 440 cases of respiratory adenovirus infections in children from the Suzhou area between 2006 and 2015].

OBJECTIVE: To study the epidemiological characteristics of respiratory adenovirus (ADV) infections in children from the Suzhou area, China. METHODS: The clinical data of ADV-positive children out of 35 529 children with respiratory tract infections who were hospitalized in the Children's Hospital of Soochow University between January 2006 and December 2015 were retrospectively studied. RESULTS: Of the 35 529 children with respiratory tract infections, 440 (1.24%) were ADV-positive. There was no significant difference in the rate of ADV infections between boys and girls (1.18% vs 1.34%). The ADV infection rates of children at the age of <1 year old, 1-3 years old, 3-7 years old and 7-14 years old were 0.39% (71/18 002), 1.12% (103/9 191), 3.14% (201/6 398), and 3.35%( 65/1 938) respectively and the rate increased with age (P<0.01). The ADV infection rates in spring [1.85%(60/8 658)] and summer [2.20%(189/8 606)] were significantly higher than in autumn [0.30%(27/8 952)] and winter [0.69%(64/9 313)] (P<0.01). CONCLUSIONS: The ADV infection rate is increased with age in the children from the Suzhou area, but it is not associated with gender. ADV infections are more common in spring and summer.

[Association of T lymphocyte subsets and allergens with Mycoplasma pneumoniae infection complicated by wheezing in infants and young children].

OBJECTIVE: To investigate the percentage of T lymphocyte subsets and allergen screening results in infants and young children with Mycoplasma pneumoniae (MP) infection complicated by wheezing. METHODS: Flow cytometry was used to measure the percentage of peripheral blood T cell subsets in 354 infants and young children with MP infection complicated by wheezing (MP wheezing group), 336 infants and young children with MP infection but without wheezing (MP non-wheezing group), and 277 children with recurrent wheezing (recurrent wheezing group). Allergen screening was also performed for these children. RESULTS: Both the MP wheezing group and recurrent wheezing group had significantly lower percentages of CD3+ and CD3+CD8+ lymphocytes than the MP non-wheezing group (p<0.05). The MP groups with or without wheezing had a significantly higher percentage of CD3+CD4+ lymphocytes than the recurrent wheezing group (p<0.05). Both the MP wheezing group and recurrent wheezing group had significantly higher percentages of CD3-CD19+ and CD19+CD23+ lymphocytes than the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest percentages (p<0.05). The overall positive rate of food allergens was significantly higher than that of inhaled allergens (30.3% vs 14.7%; p<0.05). The positive rates of food and inhaled allergens in the recurrent wheezing group and MP wheezing group were significantly higher than in the MP non-wheezing group (p<0.05), and the recurrent wheezing group had the highest rates. CONCLUSIONS: Imbalance of T lymphocyte subsets and allergic constitution play important roles in the pathogenesis of MP infection complicated by wheezing in infants and young children.

[An epidemiological study on human rhinovirus C in hospitalized children with respiratory tract infections].

OBJECTIVE: To investigate the detection rates, epidemical characteristics, and clinical features of human rhinovirus C (HRV-C) in hospitalized children with respiratory tract infections (RTIs) in Suzhou, China. METHODS: A total of 1 702 hospitalized children with RTIs from January to December, 2014 were enrolled, and 1 702 nasopharyngeal aspirate samples were collected from all children. RT-PCR was used to measure HRV mRNA, and quantitative real-time PCR combined with high-resolution melting curve was used to measure HRV-C. RESULTS: Of all children, 244 (14.34%) were detected to have HRV infection, among whom 69 (69/244, 28.3%) had HRV-C infection. The rate of mixed infection of HRV-C with other viruses and bacteria was 61% (42/69). HRV-C was detected in each month of the year, and the detection rate of HRV-C in autumn was significantly higher than that in spring, summer, and winter (P<0.05). The children aged 2-5 years had a significantly higher detection rate of HRV-C than those in the other age groups (P<0.05). Compared with HRV-A/B infection, HRV-C infection led to significantly higher proportions of patients with lobar pneumonia and acute exacerbation of asthma (P<0.05), as well as patients with increased neutrophil count and CRP level (P<0.05). There were no significant differences in sex distribution or other clinical manifestations (P>0.05). CONCLUSIONS: HRV-C infection accounts for about 1/3 of HRV infection, with a high incidence rate in autumn. The rate of mixed infection of HRV-C with other viruses and bacteria is high, and children aged 2-5 years have the highest detection rate of HRV-C. Children with HRV-C infection have similar clinical manifestations as those with HRV-A/B infection.

[Bacterial pathogenic characteristics of respiratory tract infection in children in Suzhou, China: an analysis of 14,994 cases].

OBJECTIVE: To investigate the bacterial pathogenic characteristics of respiratory tract infection in children. METHODS: The medical data from 14,994 children with respiratory tract infection who were hospitalized in Children's Hospital Affiliated to Soochow University between November 2005 and October 2014 were retrospectively reviewed. RESULTS: Among the 14,994 sputum samples from the children with respiratory tract infection, 3,947 (26.32%) had a positive bacterial culture. The most common bacterial pathogen was Streptococcus pneumonia (12.79%), followed by Haemophilus influenzae (5.02%) and Moraxella catarrhalis (2.91%). The bacterial detection rates differed significantly in different years and seasons and children of different ages (P<0.01). The children who had not taken antibacterial agents before admission had a significantly higher positive bacterial culture rate than those who had taken antibacterial agents (P<0.01). There were significant differences in the bacterial detection rate among the children with different course of disease (<1 month, 1-3 months and >3 months) (P<0.05). The detection rates of Streptococcus pneumonia, Moraxella catarrhalis and Acinetobacter baumannii showed an increased trend with a prolonged disease course (P<0.05). CONCLUSIONS: Streptococcus pneumonia is the most common bacterial pathogen causing respiratory tract infection in children, followed by Haemophilus influenzae and Moraxella catarrhalis. The detection rate of bacterial pathogens varies in different years and seasons and children of different ages. The course of the disease and application of antibacterial agents outside hospital can affect the detection rate of bacterial pathogens in children with respiratory tract infection.

Detection of human bocavirus in nasopharyngeal aspirates versus in broncho-alveolar lavage fluids in children with lower respiratory tract infections.

To compare the presence of human bocavirus (HBoV) in nasopharyngeal aspirates (NPA) versus broncho-alveolar lavage fluids (BAL) in children with lower respiratory tract infections (LRTIs), as revealed by real-time PCR, in order to confirm the diagnostic validity of NPA samples. A retrospective 5-year study was performed from 2009 to 2014 in 1,194 patients under the age of 17 years (mean age of 3 years) that were diagnosed with LRTIs and from whom both NPA and BAL were obtained. Clinical and demographic data were recorded, and NPA and BAL samples were analyzed for HBoV-positivity by real-time PCR. Of the 1,194 patients enrolled, 65 (5.4%) patients had HBoV detected from NPA, and 61 (5.1%) had HBoV detected from BAL. For HBoV, there was a significant association between the NPA and BAL samples (P < 0.001), but the diagnostic validity was relatively low (kappa = 0.414). When real-time PCR-positivity for HBoV in BAL was used as a reference for diagnosis, NPA had a good specificity and better positive predictive validity in male patients or those younger than 3 years of age. NPA has a similar yield and a good specificity for diagnosis of LRTIs with HBoV compared to BAL. The best diagnostic validity for NPA was detected in male patients or those younger than 3 years old.

[Clinical significance of MP-DNA from endotracheal aspirates in diagnosis of Mycoplasma pneumoniae pneumonia in children].

OBJECTIVE: To compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia. METHODS: A total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA. RESULTS: The positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05). CONCLUSIONS: MP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.

Comparison of severe pneumonia caused by Human metapneumovirus and respiratory syncytial virus in hospitalized children.

OBJECTIVES: The objective of this study is to compare the incidence and clinical characteristics of severe pneumonia caused by Human metapneumovirus (hMPV) to respiratory syncytial virus (RSV) infection in children. PATIENTS AND METHODS: A total of 151 children hospitalized with severe pneumonia, were tested for hMPV using reverse-transcription polymerase chain reaction. At the same time, samples were tested for RSV and other common respiratory viruses. Medical records, including clinical, laboratory data, and chest radiography findings, were reviewed for all children. RESULTS: Of the 151 samples, 88 (58.3%) were positive for respiratory viruses. Of the 88 positive, there were 6 (4.0%) with hMPV, 66 (43.7%) with RSV, 13 (8.6%) with influenza A, 2 (1.3%) with parainfluenza virus III, 1 (0.7%) with parainfluenza virus I, 1 (0.7%) with adenovirus and 1 (0.7%) with influenza B. hMPV-infected patients were significantly older than RSV-infected patients (P < 0.001). Children with hMPV pneumonia had fever more frequently (P = 0.03). Two hMPV-positive patients (33.3%) required admission to an intensive care unit, and two patients (33.3%) required mechanical ventilation. The duration of illness was 18.33 ± 7.09 days. These characteristics of hMPV infections were similar to patients with RSV infections. CONCLUSION: Human metapneumovirus is an infrequent viral pathogen causing severe pneumonia in children. Children with hMPV were older than those with RSV. The disease caused by hMPV was similar in presentation and severity to RSV, with a minority of children requiring additional respiratory support.

Etiology of acute bronchiolitis and the relationship with meteorological conditions in hospitalized infants in China.

BACKGROUND/PURPOSE: To investigate the prevalence of common viruses and Mycoplasma pneumoniae (MP) in hospitalized infants with acute bronchiolitis and study the relationship between bronchiolitis and meteorological conditions. METHODS: A 2-year prospective study was conducted on infants with a first episode of bronchiolitis admitted to Respiratory Department of Suzhou Children's Hospital. Demographic and clinical characteristics and meteorological conditions were obtained and analyzed. RESULTS: Pathogens were identified in 59.6% of 998 cases analyzed. The most frequent pathogen identified was respiratory syncytial virus (28.7%), followed by human bocavirus (11.6%), MP (9.0%), human parainfluenza virus-3 (7.8%), human metapneumovirus (6.6%), influenza A (3.5%), adenovirus (1.0%), and human parainfluenza virus-1 (0.3%). The clinical scores in children with MP or human metapneumovirus single infections, based on the assessment of severity of acute bronchiolitis, were significantly lower than in children with respiratory syncytial virus single infections. Respiratory syncytial virus had the strongest inverse correlation with mean temperature, followed by influenza A and human metapneumovirus. In addition, MP and human parainfluenza virus-3 showed positive correlations with mean temperature. CONCLUSION: Although respiratory syncytial virus was the most frequent pathogen in patients in whom bronchiolitis was diagnosed, other pathogens, including newly identified viruses and MP, also play important roles in infants with bronchiolitis. Different respiratory pathogens have different traits in response to certain meteorological conditions.

Clinical and epidemiological profiles of lower respiratory tract infection in hospitalized children due to human bocavirus in a subtropical area of China.

Lower respiratory tract infection is a major cause of morbidity and mortality in children. Human bocavirus (HBoV) is confirmed to have an association with pediatric lower respiratory tract infection. Seasonal and meteorological factors may play a key role in the epidemiology of HBoV. The purpose of this study was to ascertain the frequency, season, and clinical characteristics of hospitalized children with HBoV infection. In addition, an evaluation of the effects of meteorological factors on the incidence of HBoV in a subtropical area in China will be conducted. Children were <14 years in age and hospitalized for lower respiratory tract infection between January 1, 2009 and December 31, 2012 in the Respiratory Disease Department at the Children's Hospital affiliated to Soochow University. Multi-pathogens were detected in nasopharyngeal aspirate samples. The association between HBoV activity and regional meteorological conditions was analyzed. The average incidence of HBoV infection was 6.6% (502/7,626). Of the 502 HBoV positive children, the median age was 13 months (range 1-156 months). The HBoV infection rate was highest among the 7-12 months groups (12.9%, 163/1,267). Seasonal distribution of HBoV was noted during June to November, especially during the summer season (June to August). HBoV activity was associated with temperature and humidity although the lag effect between temperature and HBoV activity observed. HBoV is one of the most common viral pathogens in children with lower respiratory tract infection. HBoV infection occurs throughout the year with a peak during the summer. Temperature and humidity may affect the incidence of HBoV.

Soluble B7-H3 elevations in hospitalized children with Mycoplasma pneumoniae pneumonia.

The purpose of this study is to explore the associations between soluble B7-H3 (sB7-H3) and cytokines, clinical characteristics and laboratory findings. Thirty-two children with Mycoplasma pneumoniae pneumonia diagnosed by both positive serology and PCR were admitted to Children's Hospital affiliated to Soochow University. These children were enrolled and evaluated from May 2012 through September 2012. Soluble B7-H3 level and cytokines (tumor necrosis factor-α (TNF-α), interferon-γ, interleukin (IL)-4, IL-10) were determined by enzyme-linked immunosorbent assay technique. Meanwhile, clinical parameters including laboratory findings were obtained. Soluble B7-H3 level was significantly increased in patients with M. pneumoniae pneumonia compared with the levels of sB7-H3 in control subjects (4.94 ± 2.69 vs. 3.42 ± 1.48, ng/mL; P = 0.032). Furthermore, level of sB7-H3 was correlated with TNF-α level in plasma in patients with M. pneumoniae pneumonia (rp = 0.667; P < 0.001) as well as level of sB7-H3 in M. pneumoniae pneumonia subjects was also correlated with duration of symptoms (rp = 0.607; P < 0.001), percentage of neutrophil cells (rp = 0.657; P < 0.001), and C-reactive protein level (rs = 0.445; P = 0.011). Level of sB7-H3 was decreased after treatment (6.08 ± 3.07 vs. 3.55 ± 1.58, ng/mL; P = 0.019). Soluble B7-H3 maybe plays an important role in immunopathogenesis of M. pneumoniae pneumonia, especially for increasing TNF-α concentration and activation neutrophils.

[Etiology of acute respiratory tract infection in hospitalized children in Suzhou from 2005 to 2011].

OBJECTIVE: To elucidate the etiology of acute respiratory tract infection (ARI) in hospitalized children in Suzhou from 2005 to 2011. METHODS: A total of 10 243 hospitalized children with ARI in Children's Hospital Affiliated to Soochow University from September 2005 to October 2011 were enrolled in the study. The clinical information was collected; and the nasopharyngeal aspiration fluid and serum samples were sent for multi-pathogen detection. Respiratory syncytial virus (RSV), influenza virus type A and B (IV-A, IV-B), parainfluenza virus type 1-3 (PIV-1-PIV-3) and adenovirus (ADV) were detected by direct immunofluorescence assay. Human bocavirus (HBoV), mycoplasma pneumoniae (MP) and chlamydia pneumoniae (CP) were detected by fluorescent quantitative PCR while human metapneumovirus (hMPV) was detected by reverse transcription PCR (RT-PCR). Sputum culture was applied to detect bacterial infection and quantitative ELISA was adopted to detect the specific antibodies of MP and CP. The results of the above detections were analyzed, and thereby to explore the prevalent pathogens among different aging children and the seasonal distribution and characteristics of the disease. RESULTS: At least one type of pathogen was detected in 5871 out of 10 243 hospitalized children and the overall positive rate was 57.32%; including 3326 virus samples with positive rate at 32.47% (3326/10 243), 2870 bacteria samples with positive rate at 28.02% (2870/10 243) and 2759 atypical pathogen samples,with positive rate at 26.94% (2759/10 243). MP was the most common pathogen,whose detected rate was 25.74% (2637/10 243). The median age of children with RSV (6 months) or PIV-3(8 months) infection was younger than the median age of all hospitalized children (12 months) (χ(2) = 380.992, 34.826, P < 0.05). While the median age of children with ADV (42 months), HBoV (14 months) or IV-A (24 months) infection was older than it of all hospitalized children (χ(2) = 83.583, 13.169, 18.012, P < 0.05). The median age of children with MP (30 months),streptococcus pneumoniae (17 months) or haemophilus parainfluenzae (21 months) infection was older than it of all hospitalized children (χ(2) = 728.299, 60.463, 8.803, P < 0.05). The detected rate of RSV in the groups of children aging less than 6 months, 7-12 months, 2-3 years, 4-5 years and over 6 years was separately 25.59% (840/3283), 17.05% (333/1953), 11.85% (310/2615), 6.68% (90/1347), and 2.87% (30/1045); which decreased while the age grew (χ(2) = 178.46, P < 0.01). Conversely, the positive rate of MP increased with the age growing (χ(2) = 379.21, P < 0.01). The rate in the above groups was 8.25% (271/3283), 19.46% (380/1953), 33.00% (863/2615), 41.43% (558/1347), 54.07% (565/1045), respectively. RSV and IV-A were prevalent in winter, whose detected rates were 35.73% (941/2634) and 4.44% (117/2634) respectively.hMPV infection was common in spring, with the detected rate at 10.55% (278/2634); while HBoV infection was common in summer and autumn, with the positive rate at 9.99% (149/1491) and 9.71% (98/1009). MP and CP were frequently detected in summer, up to 31.27% (819/2619) and 10.07% (43/427) respectively. RSV was the most common pathogen in bronchiolitis (33.27% (866/2603)) and MP was the most common pathogen in bronchopneumonia (26.05% (1152/4422)) and lober pneumonia (52.25% (267/511)). CONCLUSION: MP and RSV were the most common pathogens in respiratory tract infection in hospitalized children. The novel virus included hMPV and HBoV, which also played an important role in ARI. Different pathogens were prevalent in different ages; with respective seasonal distribution and characteristics.

Therapeutic effects of anti-B7-H3 antibody in an ovalbumin-induced mouse asthma model.

BACKGROUND: B7 molecules play a key role in regulating allergen-induced T cell activation in asthma, which may occur through T cell recruitment and T helper cell differentiation on allergen provocation. Initial studies have shown that B7-H3 (CD276), a recently identified B7 family member, plays a critical role in the development of Th2 cells. OBJECTIVE: To investigate the effects of anti-B7-H3 monoclonal antibody (mAb) in a mouse model of allergic asthma. METHODS: The asthma model was established by ovalbumin (OVA) sensitization and challenging in female BALB/c mice. Total cell numbers in bronchoalveolar lavage fluid (BALF) were determined, and the expression levels of interferon gamma (IFN-γ), interleukin (IL)-4, and IL-17 in BALF were measured by enzyme-linked immunosorbent assay. Pulmonary eosinophil infiltration and mucus production were detected by hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS), respectively. B7-H3 expression was detected by immunohistochemistry in frozen tissue sections. RESULTS: Anti-B7-H3 mAb treatment alleviated the asthmatic syndrome, decreased the levels of B7-H3-positive cells in the lung tissues, abrogated hypercellularity, eosinophil infiltration, and mucus production, and inhibited IL-4 and IL-17 production in BALF at the induction phase as compared with the immunoglobulin G (IgG) control group (P < .01). In addition, the treatment of anti-B7-H3 mAb at the induction phase could increase the expression levels of IFN-γ as compared with the IgG control group (P < .01). Anti-B7-H3 mAb treatment at the effector phase did not inhibit the asthma response. CONCLUSION: Blockade of B7-H3 signals may provide a novel therapeutic approach to the treatment of allergic asthma.

Seasonal distribution and epidemiological characteristics of human metapneumovirus infections in pediatric inpatients in Southeast China.

Human metapneumovirus (hMPV) is an important respiratory pathogen in young children whose seasonal activity varies substantially from year to year among different populations. This study was conducted to investigate if there was a seasonal variation in the incidence of hMPV infection in young children and possible associations between hMPV infection and local meteorological parameters in Suzhou, China. A total of 6,655 children with acute respiratory tract infection (ARTI) admitted to the Children's Hospital affiliated to Soochow University, Suzhou, were tested from January 2006 to December 2009 for the presence of hMPV using reverse-transcription polymerase chain reaction. The relationship between the presence of the virus and regional meteorological conditions was analyzed by linear and multivariate regression analysis. The overall hMPV infection incidence over the four-year study was 8.2 %, 8.1 %, 12.7 % and 7.4 % per year, respectively. Four hundred eighty-eight hMPV-positive children (78.2 %) were younger than 3 years of age. hMPV infections appear to have a seasonal distribution in Suzhou. In 2006, 2007 and 2009, the peak seasons were in December to January, while in 2008, the peak of hMPV activity occurred in May. The incidence of hMPV infection was negatively correlated with the average monthly temperature and rainfall. hMPV was one of the most common viral pathogens after respiratory syncytial virus that was associated with acute respiratory tract infection in children in Suzhou. hMPV infection occurred throughout the year with peaks during late winter and early spring. Climatic factors, especially monthly average temperature, may affect the prevalence of hMPV in Suzhou.

[Characteristics and the prevalence of respiratory viruses and the correlation with climatic factors of hospitalized children in Suzhou children's hospital].

OBJECTIVE: To study the epidemiological characteristics of respiratory virus infection and its relations to climatic factors in Suzhou. METHODS: From 2006 to 2009, viral etiology surveillance was conducted among 6655 children hospitalized with acute respiratory tract infections (ARIs). Direct immunofluorescence method was used to test respiratory secretion samples for respiratory syncytial virus (RSV), influenza viruses A and B (Inf-A, Inf-B), parainfluenza virus types I, II, and III (Pinf-I, Pinf-II, Pinf-III) and adenovirus. Samples were tested for human metapneumovirus (hMPV) with reverse transcription polymerase chain reaction (RT-PCR). Samples from Jan 2006 to Dec 2009 were also tested for human bocavirus (HBoV). Climatic factors, including mean temperature, relative humidity, rainfall amount, sum of sunshine and mean wind velocity were collected monthly. The relationship between activity of each virus and climatic factors were analyzed by linear regression and stepwise regression analysis. RESULTS: From 2006 to 2009, in the total virus detection rate was 32.2% (2142/6655) in Suzhou. RSV was the most common virus and the average detection rate was 15.7% (1048/6655), followed by hMPV 8.9% (596/6655), HBoV 7.8% (148/1883), Pinf-III 2.7% (183/6655), Inf-A 2.4% (161/6655), ADV 1.3% (89/6655), Pinf-I 0.4% (29/6655), Inf-B 0.37% (25/6655) and Pinf-II 0.16% (11/6655). The positive rates of RSV, hMPV and ADV were significantly different in four years (χ(2) = 17.71, 33.23, 8.42, all P values < 0.05). Different virus has different epidemiological characteristics and distinct seasonality. The detection rate of RSV, hMPV, Inf-A were higher in Winter as 37.2%, 13.2%, 4.4%, respectively. ADV and Pinf-III were higher in summer as 2.3% and 4.6% respectively. The peak of HBoV existed in Autumn as 3.3%. The total virus detection rate showed significant inverse correlation with month average temperature (r = -0.732, P < 0.001) and a weak inverse correlation with average wind velocity was also found (r = -0.36, 0.01 < P < 0.05). The highest month total virus detection rate was from 47.6% to 84.4% when average temperature was from 3.2°C to 9.4°C and mean wind velocity was from 1.2 - 1.9 m/s. The associations of average temperature, sum of sunshine and wind velocity with RSV activity were statistical significant (r = -0.88, P < 0.001; r = -0.43, P < 0.01; r = -0.47, P < 0.01). The highest rate was from 24.3% to 58.2%, when mean temperature was from 5.3°C to 19.9°C, mean wind velocity was from 1.3 - 2.4 m/s and sum of sunshine was 61.0 to 153.4 hours. hMPV detection rate was inversely correlated with mean temperature and rain account (r = -0.43, P < 0.01; r = -0.29, P < 0.05). The rate was highest from 11.7% to 31.6% when mean temperature was from 5.3°C to 21.9°C and rain account was from 27.5 millimeter to 150.9 millimeter. Only mean temperature was positively correlated with Pinf-III (r = 0.53, P < 0.001). The rate was from 2.8% to 7.2% when mean temperature was between 11.9°C and 30.4°C. ADV detection rate was positively correlated with mean temperature and sum of sunshine, but negatively correlated with wind velocity (r = 0.35, P < 0.05; r = 0.30, P < 0.05; r = -0.32, P < 0.05). The rate was from 2.2% to 6.6% when mean temperature was between 15.9°C and 30.4°C, and sum of sunshine between 93 hours to 240.7 hours and mean wind velocity was from 1.1 - 2.8 m/s. Average temperature and relative humidity showed interactions on the detection rate of ADV (r = 0.36, P = 0.0093; r = -0.34, P = 0.016), but temperature showed higher effect on ADV detection rate. ADV detection rate was high at higher temperature (15.9 - 30.4°C) and low humidity (56% - 71%). CONCLUSION: RSV was one of the most common viruses among hospitalized children in Suzhou, and hMPV and HBoV also played an important role in respiratory tract infection of children. Different virus has different cycle and seasonality. Climatic factors, especially mean temperature, was the main factor affecting the virus prevalence.