Expert consensus on the diagnosis and treatment of macrolide-resistant Mycoplasma pneumoniae pneumonia in children.

BACKGROUND: Mycoplasma pneumoniae (M. pneumoniae) is a significant contributor to community-acquired pneumonia among children. Since 1968, when a strain of M. pneumoniae resistant to macrolide antibiotics was initially reported in Japan, macrolide-resistant M. pneumoniae (MRMP) has been documented in many countries worldwide, with varying incidence rates. MRMP infections lead to a poor response to macrolide antibiotics, frequently resulting in prolonged fever, extended antibiotic treatment, increased hospitalization, intensive care unit admissions, and a significantly higher proportion of patients receiving glucocorticoids or second-line antibiotics. Since 2000, the global incidence of MRMP has gradually increased, especially in East Asia, which has posed a serious challenge to the treatment of M. pneumoniae infections in children and attracted widespread attention from pediatricians. However, there is still no global consensus on the diagnosis and treatment of MRMP in children. METHODS: We organized 29 Chinese experts majoring in pediatric pulmonology and epidemiology to write the world's first consensus on the diagnosis and treatment of pediatric MRMP pneumonia, based on evidence collection. The evidence searches and reviews were conducted using electronic databases, including PubMed, Embase, Web of Science, CNKI, Medline, and the Cochrane Library. We used variations in terms for "macrolide-resistant", "Mycoplasma pneumoniae", "MP", "M. pneumoniae", "pneumonia", "MRMP", "lower respiratory tract infection", "Mycoplasma pneumoniae infection", "children", and "pediatric". RESULTS: Epidemiology, pathogenesis, clinical manifestations, early identification, laboratory examination, principles of antibiotic use, application of glucocorticoids and intravenous immunoglobulin, and precautions for bronchoscopy are highlighted. Early and rapid identification of gene mutations associated with MRMP is now available by polymerase chain reaction and fluorescent probe techniques in respiratory specimens. Although the resistance rate to macrolide remains high, it is fortunate that M. pneumoniae still maintains good in vitro sensitivity to second-line antibiotics such as tetracyclines and quinolones, making them an effective treatment option for patients with initial treatment failure caused by macrolide antibiotics. CONCLUSIONS: This consensus, based on international and national scientific evidence, provides scientific guidance for the diagnosis and treatment of MRMP in children. Further studies on tetracycline and quinolone drugs in children are urgently needed to evaluate their effects on the growth and development. Additionally, developing an antibiotic rotation treatment strategy is necessary to reduce the prevalence of MRMP strains.

Clinical features of severe Mycoplasma pneumoniae pneumonia with pulmonary complications in childhood: A retrospective study.

INTRODUCTION: Incidence of severe M. pneumoniae pneumonia (SMPP) reported in China has been increasing over the last decade. We aimed to evaluate the clinical features of pediatric SMPP with pulmonary complications, according to laboratory tests and chest radiographic resolution patterns. MATERIAL AND METHODS: We retrospectively reviewed 93 SMPP patients between January 2016 and February 2019, and grouped them by pneumonia pattern: pulmonary complications (63 patients) and extensive lung lesions without pulmonary complications (30 patients). RESULTS: SMPP patients with pleural effusion (medium or large) and necrotizing pneumonia showed longer duration of fever, high serum value of lactate dehydrogenase (LDH), d-dimer, and LDH to albumin ratio (LAR). LAR and  d-dimer were associated with moderate or massive pleural effusion, and  d-dimer was associated with lung necrosis. The average time of radiographic resolution in the pulmonary complication group was 12 weeks, while those with elevated d-dimer were significantly more likely to have longer time for radiographic clearance. CONCLUSION: We conclude that M. pneumoniae pneumonia in patients with pleural effusion (medium or large) or lung necrosis was more severe than those without pulmonary complications. LAR and  d-dimer might be used as parameters to identify children susceptible to pleural effusion (medium or large) or lung necrosis, and longer time for radiographic clearance among pediatric patients of SMPP.

[Clinical characteristics of plastic bronchitis and risk factors for recurrence in children]. / å„¿ç«¥å¡‘åž‹æ€§æ”¯æ°”ç®¡ç‚Žä¸´åºŠç‰¹å¾åŠå¤å‘å±é™©å› ç´ åˆ†æž.

OBJECTIVES: To study the clinical characteristics of plastic bronchitis (PB) in children and investigate the the risk factors for recurrence of PB. METHODS: This was a retrospective analysis of medical data of children with PB who were hospitalized in Children's Hospital of Chongqing Medical University from January 2012 to July 2022. The children were divided into a single occurrence of PB group and a recurrent PB group and the risk factors for recurrence of PB were analyzed. RESULTS: A total of 107 children with PB were included, including 61 males (57.0%) and 46 females (43.0%), with a median age of 5.0 years, and 78 cases (72.9%) were over 3 years old. All the children had cough, 96 children (89.7%) had fever, with high fever in 90 children. Seventy-three children (68.2%) had shortness of breath, and 64 children (59.8%) had respiratory failure. Sixty-six children (61.7%) had atelectasis and 52 children (48.6%) had pleural effusion. Forty-seven children (43.9%) had Mycoplasma pneumoniae infection, 28 children (26.2%) had adenovirus infection, and 17 children (15.9%) had influenza virus infection. Seventy-one children (66.4%) had a single occurrence of PB, and 36 cases (33.6%) had recurrent occurrence of PB (≥2 times). Multivariate logistic regression analysis showed that involvement of ≥2 lung lobes (OR=3.376) under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts (OR=3.275), and concomitant multi-organ dysfunction outside the lungs (OR=2.906) were independent risk factors for recurrent occurrence of PB (P<0.05). CONCLUSIONS: Children with pneumonia accompanied by persistent high fever, shortness of breath, respiratory failure, atelectasis or pleural effusion should be highly suspected with PB. Involvement of ≥2 lung lobes under bronchoscopy, continued need for invasive ventilation after initial removal of plastic casts, and concomitant multi-organ dysfunction outside the lungs may be risk factors for recurrent occurrence of PB.

[Clinical and bronchoscopy features of tracheobronchial tuberculosis in children]. / å„¿ç«¥æ°”ç®¡æ”¯æ°”ç®¡ç»“æ ¸çš„ä¸´åºŠåŠæ”¯æ°”ç®¡é•œä¸‹ç‰¹å¾åˆ†æž.

OBJECTIVES: To study the clinical and bronchoscopic characteristics of tracheobronchial tuberculosis (TBTB) in children and to identify factors influencing residual airway obstruction or stenosis. METHODS: The clinical data of children with TBTB were retrospectively collected. The children were divided into two groups based on the last bronchoscopic result within one year of follow-up: a group with residual airway obstruction or stenosis (n=34) and a group without residual airway obstruction or stenosis (n=58). A multivariate logistic regression analysis was used to identify the factors influencing residual airway obstruction or stenosis in children with TBTB. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of the factors influencing residual airway obstruction or stenosis in children with TBTB. RESULTS: A total of 92 children with TBTB were included, and the main symptoms were cough (90%) and fever (68%). In children under 1 year old, the incidence rates of dyspnea and wheezing were significantly higher than in other age groups (P<0.008). Chest CT findings included mediastinal or hilar lymph node enlargement (90%) and tracheobronchial stenosis or obstruction (61%). The lymphatic fistula type was the main type of TBTB observed bronchoscopically (77%). All children received interventional treatment, and the effective rate was 84%. During one year of follow-up, 34 children had residual airway obstruction or stenosis. The TBTB diagnostic time and the initiation of interventional treatment were significantly delayed in the group with residual airway obstruction or stenosis compared with the group without residual airway obstruction or stenosis (P<0.05). The multivariate logistic regression analysis showed that the TBTB diagnostic time was closely related to residual airway obstruction or stenosis in children (P<0.05). ROC curve analysis showed that at the cut-off value of 92 days of TBTB diagnostic time, the area under the curve for predicting residual airway obstruction or stenosis in children with TBTB was 0.707, with a sensitivity of 58.8% and a specificity of 75.9%. CONCLUSIONS: The clinical manifestations of TBTB are nonspecific, and symptoms are more severe in children under 1 year old. TBTB should be suspected in children with tuberculosis and chest imaging indicating airway involvement. Delayed diagnosis of TBTB is associated with the development of residual airway obstruction or stenosis.

[The Effect of Interventional Treatment with Bronchoscopy in 10 Children with Acquired Subglottic Stenosis].

OBJECTIVE: To explore the effects of interventional therapy with bronchoscopy in children with acquired subglottic stenosis (SGS). METHODS: The clinical data of ten pediatric inpatients with acquired SGS who were admitted to Children's Hospital of Chongqing Medical University, as well as their follow-up information obtained 1 week, 1 month, 3 months and 6 months after the procedure was done.were retrospectively analyzed to examine the effect of interventional bronchoscopic therapies, including balloon dilatation, holmium laser, and cryotherapy, in pediatric patients with acquired SGS. RESULTS: Among the 10 patients with acquired SGS, there were 5 boys and 5 girls aged between 1 month and 6 years and 5 months, with a median age of 11 months and 1 day. Among the 5 patients with acute acquired SGS, two were treated with balloon dilatation only, with one cured and one showing clinical improvement, while three received comprehensive interventional therapy combining balloon dilatation, holmium laser, and cryotherapy, with two cured and one showing improvement. Among the 5 patients with chronic acquired SGS, four cases were cured with comprehensive interventional therapy, while one case suffered from aggravated upper airway obstruction 4 + hours after balloon dilatation. The patient was subsequently put on invasive mechanical ventilation for 4 days, but was unable to be extubated. The parents signed do-not-resuscitate order and the patient died afterwards. Bronchoscopy performed 1 week, 1 month and 3 months after the procedure was done showed that the SGS was improved to varying degrees. CONCLUSION: Bronchoscopy intervention is an effective therapy for acquired SGS in children.

[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.

The Impact of Weather and Air Pollution on Viral Infection and Disease Outcome Among Pediatric Pneumonia Patients in Chongqing, China, from 2009 to 2018: A Prospective Observational Study.

BACKGROUND: For pediatric pneumonia, the meteorological and air pollution indicators have been frequently investigated for their association with viral circulation but not for their impact on disease severity. METHODS: We performed a 10-year prospective, observational study in 1 hospital in Chongqing, China, to recruit children with pneumonia. Eight commonly seen respiratory viruses were tested. Autoregressive distributed lag (ADL) and random forest (RF) models were used to fit monthly detection rates of each virus at the population level and to predict the possibility of severe pneumonia at the individual level, respectively. RESULTS: Between 2009 and 2018, 6611 pediatric pneumonia patients were included, and 4846 (73.3%) tested positive for at least 1 respiratory virus. The patient median age was 9 months (interquartile range, 4‒20). ADL models demonstrated a decent fitting of detection rates of R2 > 0.7 for respiratory syncytial virus, human rhinovirus, parainfluenza virus, and human metapneumovirus. Based on the RF models, the area under the curve for host-related factors alone was 0.88 (95% confidence interval [CI], .87‒.89) and 0.86 (95% CI, .85‒.88) for meteorological and air pollution indicators alone and 0.62 (95% CI, .60‒.63) for viral infections alone. The final model indicated that 9 weather and air pollution indicators were important determinants of severe pneumonia, with a relative contribution of 62.53%, which is significantly higher than respiratory viral infections (7.36%). CONCLUSIONS: Meteorological and air pollution predictors contributed more to severe pneumonia in children than did respiratory viruses. These meteorological data could help predict times when children would be at increased risk for severe pneumonia and when interventions, such as reducing outdoor activities, may be warranted.

[Predictive factors for failure of continuous positive airway pressure treatment in infants with bronchiolitis].

OBJECTIVE: To study the predictive factors for the failure of continuous positive airway pressure (CPAP) treatment in infants with bronchiolitis. METHODS: A retrospective analysis was performed on the clinical data of 310 hospitalized children (aged 1-12 months) with bronchiolitis treated with CPAP. Their clinical features were compared between the successful treatment group (270 cases) and the failed treatment group (40 cases). A multivariate logistic regression analysis was used to explore the predictive factors for failure of CPAP treatment. RESULTS: The multivariate logistic regression analysis showed that the score of the Pediatric Risk of Mortality III (PRISM III) ≥10 (OR=13.905), development of atelectasis (OR=12.080), comorbidity of cardiac insufficiency (OR=7.741), and no improvement in oxygenation index (arterial partial pressure of oxygen/fraction of inhaled oxygen, P/F) after 2 hours of CPAP treatment (OR=34.084) were predictive factors for failure of CPAP treatment for bronchiolitis (P<0.05). In predicting CPAP treatment failure, no improvement in P/F after 2 hours of CPAP treatment had an area under the receiver operating characteristic curve of 0.793, with a sensitivity of 70.3% and a specificity of 82.4% at a cut-off value of 203. CONCLUSIONS: No improvement in P/F after 2 hours of CPAP treatment, PRISM III score ≥10, development of atelectasis, and comorbidity of cardiac insufficiency can be used as predictive factors for CPAP treatment failure in infants with bronchiolitis.

[Current status of antibiotic therapy for Staphylococcus aureus sepsis in children].

OBJECTIVE: To investigate the current status of empirical antibiotic therapy for children with Staphylococcus aureus sepsis and the effect of therapeutic paradigm on prognosis based on a retrospective analysis. METHODS: A total of 78 children with Staphylococcus aureus sepsis who were admitted from January 2014 to August 2017 were enrolled. According to the preferred empirical antibiotics before the detection of Staphylococcus aureus by blood culture, these children were divided into a carbapenem group with 16 children, a ß-lactam group with 37 children, a vancomycin group with 15 children and a vancomycin+ß-lactam group with 10 children. A retrospective analysis was performed for related clinical data including general status, underlying diseases, Acute Physiology and Chronic Health Evaluation II (APACHE II) score, history of use of immunosuppressant, drug resistance to methicillin and prognosis. A logistic regression analysis was used to investigate the effect of empirical antibiotic therapy on the clinical outcome and prognosis of children with Staphylococcus aureus sepsis. RESULTS: There were no significant differences among these groups in general status, underlying diseases, history of use of immunosuppressant, APACHE II score, nosocomial infection and detection rate of methicillin-resistant Staphylococcus aureus (P>0.05). There were significant differences in the incidence rate of septic shock and in-hospital mortality among these four groups (P<0.05). The carbapenem group had the highest incidence rate of septic shock and in-hospital mortality (69% and 50% respectively). The multivariate logistic regression analysis showed that empirical antibiotic therapy with different antibiotics had different risks for septic shock and in-hospital death in children with Staphylococcus aureus sepsis (P<0.05), and that an APACHE II score of ≥15 was an independent risk factor for septic shock in these children (P<0.05). The carbapenem group had significantly higher risks of septic shock and in-hospital death than the vancomycin group (P<0.05). CONCLUSIONS: Inappropriate empirical use of antibiotics may lead to a poor prognosis in children with Staphylococcus aureus sepsis. Empirical use of carbapenems is not recommended for children suspected of Staphylococcus aureus sepsis.

Epidemiological characteristics of nasopharyngeal Streptococcus pneumoniae strains among children with pneumonia in Chongqing, China.

Streptococcus pneumoniae (pneumococcus) is the most common respiratory pathogen worldwide. Nasopharyngeal carriage with S. pneumoniae is the major source of lower respiratory tract infection and horizontal spread among children. Investigating nasopharyngeal S. pneumoniae is crucial for clinicians to control pneumococcus disease. Here, we retrospectively analyzed clinical information of 5,960 hospitalized children, focusing on pneumonia children less than five years with positive nasopharyngeal pneumococcal cultures. Nasopharyngeal aspirates (NPAs) were collected between June 2009 and December 2016, which were outside the pneumococcal conjugate vaccine(PCV) period. NPAs were subjected to common bacterial culture and antibiotic susceptibility tests, and serotypes were identified by both multiplex PCR and DNA sequencing. Results clearly revealed that clinical manifestations of the children whose NPAs were S. pneumoniae culture positive were serious, especially in those less than twelve months old. Fifteen different serotypes of nasopharyngeal S. pneumoniae were detected, the most common ones being 19F (35.2%), 6A/B (23.8%), 19A (11.4%), 15B/C (9.3%) and 23F (7.8%). Eight serotypes, accounting for 85.5% of the isolates, corresponded to the PCV13 serotypes. Approximately one-third of all S. pneumoniae strains were susceptible to penicillin. Overall, we consider nasopharyngeal S. pneumoniae culture is beneficial in assessing the situations of pneumonia children. Moreover, PCV13 could be useful in preventing pneumococcal disease in Chongqing, China.

Association between secondary thrombocytosis and viral respiratory tract infections in children.

Secondary thrombocytosis (ST) is frequently observed in children with a variety of clinical conditions. The leading cause of ST is respiratory tract infection (RTI) in children. Nasopharyngeal aspirate samples were collected and assessed for common respiratory viruses. The relationships between virus infections and secondary thrombocytosis were analyzed retrospectively. The blood platelet count and the presence of respiratory viruses were determined for 3156 RTI patients, and 817 (25.9%) cases with platelet ≥500 × 10(9)/L were considered as the thrombocytosis group. Compared with the normal group, the detection rates of respiratory syncytial virus (RSV) and human rhinovirus (HRV) were significantly higher in the thrombocytosis group (P = 0.017 and 0.042, respectively). HRV single infection was a risk factor associated with thrombocytosis [odds ratio (OR) = 1.560, 95% confidence interval (CI) = 1.108-2.197]. Furthermore, ST was more likely to occur in younger patients who had clinical manifestations of wheezing and dyspnea and who had been diagnosed with bronchiolitis. Furthermore, the course of disease lasted longer in these patients. ST is associated with viral respiratory tract infections, especially RSV and HRV infections. HRV single infection is a risk factor associated with thrombocytosis.

Association of Pneumococcal Carriage and Expression of Foxp3+ Regulatory T Cells and Th17 Cells in the Adenoids of Children.

BACKGROUND: Pneumococcal carriage in the nasopharynx is a primary means of transmission and a necessary prerequisite for pneumococcal disease. OBJECTIVES: We analyzed the relationship between expressions of Foxp3+ regulatory T (Treg) cells and Th17 cells, and pneumococcal carriage in the adenoids of children who were either positive or negative for pneumococci. METHODS: We collected adenoidal tissue and nasopharyngeal swab samples from children undergoing an adenoidectomy. Adenoidal mononuclear cells were isolated, cultured and then stimulated with culture concentrated supernatant (CCS) obtained from a D39 bacterial strain. RESULTS: Foxp3+ Treg cells were upregulated and Th17 cells were downregulated in populations of adenoidal mononuclear cells obtained from the pneumococcus-positive group. Following CCS stimulation, the increment in Foxp3+ Treg cells in the pneumococcus-positive group was significantly greater than that in the pneumococcus-negative group, while the increment in Th17 cells was less as compared to that in the pneumococcus-negative group. These results were consistent with variations in levels of Foxp3 mRNA and retinoic acid receptor-related orphan receptor-γt mRNA in adenoidal mononuclear cells. Levels of IL-17A and IL-6 in adenoid tissue were higher in the pneumococcus-negative group, and the levels of TGF-ß in adenoid tissue were lower in the pneumococcus-negative group compared to the pneumococcus-positive group. Pneumococcal carriage in children was closely associated with the expressions of Foxp3+ Treg and Th17 cells in the adenoid. CONCLUSION: Upregulation of Foxp3+ Treg cells might downregulate the production of Th17 cells in the adenoid, resulting in decreased scavenging of Streptococcus pneumoniae and chronic pneumococcal carriage.

[Clinical features of inhaled and blood-borne Staphylococcus aureus pneumonia and analysis of antibiotic resistance of the pathogen in children].

OBJECTIVE: To compare the clinical manifestations between inhaled and blood-borne Staphylococcus aureus pneumonia (SAP) and the antibiotic resistance between the isolates of inhaled and blood-borne Staphylococcus aureus. METHODS: The clinical data of 44 pediatric SAP cases in the Children′s Hospital, Chongqing Medical University from January 2008 to December 2013 were retrospectively analyzed. Twenty-four cases were identified as inhaled SAP, and 20 cases as blood-borne SAP. RESULTS: Inhaled SAP was more common in children younger than 3 years of age, while blood-borne SAP was more prevalent in children older than 6 years of age. Patients with inhaled SAP had significantly higher incidence rates of cough, wheeze, moist rales, dyspnea and empyema than those with blood-borne SAP (P<0.05). The patients with blood-borne SAP were more vulnerable to severe fever, unconsciousness, dysfunction of liver and kidney, pyogenic osteomyelitis, septic arthritis, sepsis, and abscess of skin and soft tissues (P<0.05). Inhaled SAP isolates had significantly higher rates of resistance to amoxicillin/clavulanic acid, oxacillin, and cefoxitin than blood-borne SAP isolates (P<0.05), while the latter had a higher rate of resistance to cotrimoxazole (P<0.05). CONCLUSIONS: Inhaled SAP often occurs in children younger than 3 years of age, and the respiratory manifestations are commonly seen. Blood-borne SAP often occurs in children older than 6 years of age, with the infectious-toxic symptoms that result in multiple organ infection and dysfunction. The isolates of inhaled and blood-borne SAP have different antibiograms.

[Analysis of serum vancomycin concentration after administration of different doses in children with Staphylococcus aureus pneumonia].

OBJECTIVE: To analyze serum vancomycin concentration after administration of different therapeutic doses in children with Staphylococcus aureus pneumonia (SAP) in order to determine the appropriate dose of vancomycin in clinical administration. METHODS: The clinical data of 35 children who were diagnosed with SAP and treated with vancomycin from January 2008 to December 2013 were retrospectively analyzed. RESULTS: Among the 35 SAP cases with vancomycin therapy, 22 cases (63%) had serum vancomycin trough concentration monitored. The numbers of cases with vancomycin at 10, 12.5, and 15 mg/(kg·dose) × every 6 hours (q6h) were 11, 4 and 7, respectively. The mean serum trough concentration of vancomycin in the 15 mg/(kg·dose) group was 14.98 mg/L, which was significantly higher than in the 10 mg/(kg·dose) and 12.5 mg/(kg·dose) groups (4.97 and 8.00 mg/L respectively; P<0.05). The percentage of cases that reached the expected trough concentration in the 15 mg/(kg·dose) group (71%) was significantly higher than that in the 10 mg/(kg·dose) group (9%), but there was no significant difference in this percentage between the 15 mg/(kg·dose) and 12.5 mg/(kg·dose) groups (71% vs 25%). CONCLUSIONS: The reasonable dosage of vancomycin for the treatment of pediatric SAP is 15 mg/(kg·dose) × q6h or 60 mg/(kg·d).

[Clinical analysis of 28 cases of bronchiolitis obliterans].

OBJECTIVE: To study the clinical features of bronchiolitis obliterans (BO) in children. METHODS: The clinical data of 28 children with BO between July 2007 and April 2012 was retrospectively reviewed. RESULTS: All patients presented with persistent or repeated cough and wheezing. Twenty-three cases were post-infectious bronchiolitis obliterans (PIBO), among whom the etiology were adenovirus (12 cases), measles (2 cases), influenza virus A (2 cases), mycoplasma pneumoniae (1 case), mycoplasma pneumoniae coinfection with adenovirus (1 case), respiratory syncytial virus coinfection with Parainfluenza type 3 virus (1 case) and pulmonary tuberculosis (1 case). The etiology of 3 cases was not associated with infection. The etiology was unknown in 2 cases. Pulmonary HRCT revealed that decreased density in 25 cases, mosaic perfusion in 21 cases, bronchial wall thickening in 15 cases, bronchiectasis in 12 cases and air retention in 6 cases. Lung function test was performed on 21 cases and demonstrated that obstructive ventilation disorder in all 21 cases. Bronchodilation test was performed on 18 cases and 17 cases showed a negative result. All 28 cases received corticosteroid treatment, and 24 cases were orally administered with low doses of azithromycin. One case died during hospitalization. Eighteen cases were followed up for 4 months to 4 years and seven months. Clinical manifestations were improved in 12 cases and one case died. CONCLUSIONS: Low respiratory infection is the most common cause of pediatric BO and adenovirus is a major pathogen. Persistent wheezing and cough were main clinical manifestations. Pulmonary HRCT imaging is important for diagnosis and follow-up of BO. Lung function test can typically show obstructive ventilation disorder. Corticosteroid and methotrexate may be effective for treatment of BO. Prognosis of this disease is unsatisfactory. Early diagnosis and treatment, and avoidance of repeated respiratory tract infection may be helpful to improve the prognosis.

[Etiology of nonspecific chronic cough in children and relationship between TRPV1 gene polymorphisms and nonspecific chronic cough].

OBJECTIVE: To explore the causes of nonspecific chronic cough in children and relationship between transient receptor potential vanilloid 1 (TRPV1) gene polymorphisms and nonspecific chronic cough. METHODS: A total of 195 children with chronic cough were followed up half a month, one month and three months after their first visit to hospital. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine polymorphisms of the TRPV1 gene in the children. A total of 205 healthy or surgical children without chronic cough served as the control group. RESULTS: The etiologic distribution of the 195 children with chronic cough was as follows: 96 (49.2%) cases of cough variant asthma (CVA), 48 (24.6%) cases of CVA complicated by upper airway cough syndrome (UACS), 34 (17.4%) cases of post-infectious cough, and 17 (8.7%) cases of UACS. Three genotypes were identified in both groups at positions rs222747 (CC, GC and GG), rs222748 (CC, TC and TT) and rs8065080 (CC, TC and TT). The frequencies of genotype and allele at position rs222747 did not accord with the law of Hardy-Weinberg. There was no significant difference in frequencies of genotype and allele at positions rs222748 and rs8065080 between the two groups. CONCLUSIONS: CVA, UACS and post-infectious cough are common causes of nonspecific chronic cough in children. TRPV1 gene polymorphisms at positions rs222748 and rs8065080 may be unrelated to nonspecific chronic cough in children.

[Proportion of incidence of etiological agents in children with non-specific chronic cough in Chongqing: a follow-up study].

OBJECTIVE: To investigate the proportion of incidence of children with non-specific chronic cough in Chongqing and analyze the characteristics of etiology during the follow-up. METHOD: Diagnostic criteria were defined for children with non-specific chronic cough according to the Guidelines of diagnosis and therapy for children with chronic cough that were formulated by the Subspecialty Group, Society of Pediatrics, Chinese Medical Association and Chinese Journal of Pediatrics in 2008. Totally 266 patients in whom cough was the main or the only symptom,lasting > 4 weeks, presenting to Asthma Center of Children's Hospital, Chongqing Medical University between June 2008 and April 2009 were recruited into this study. Based on the Guidelines, diagnosis was made after taking history, physical examination and assistant examination. After etiological treatment, the patients were followed up during the second week, the fourth week and the twelfth week. Etiological diagnosis was confirmed if cough was resolved after specific therapy. If cough was not resolved,the diagnosis was rechecked and a new therapy was applied. RESULT: Totally 125 (47.0%) patients received final diagnoses of cough variant asthma (CVA), 58 (21.8%) was CVA and upper airway cough syndrome (UACS), 44 (16.5%) was diagnosed postinfection cough, 35 (13.2%) of UACS. In different age groups, the proportion of incidence of etiological agents is statistically distinct. In the ≤ 3 years old group, 35 patients (70.0%) were diagnosed CVA, 10 (20.0%) was postinfection cough; in 3 - 6 years group, 71 patients (50.7%) had CVA; the incidence of UACS was significantly higher in ≥ 6 years group. CONCLUSION: It is concluded that CVA, CVA and UACS, post infection cough, and simple UACS were identified as the three top reasons for children with chronic cough in Chongqing. Children with chronic cough of different age groups had different etiology of cough. The characteristic of each etiology need further study.

[Construction and identification of yeast expression plasmids containing mouse signal transducers and activators of transcription-4/6].

AIM: To construct yeast expression plasmids containing mouse STAT4/6 gene for further study of their interaction with other proteins in yeast two-hybrid system. METHODS: Mouse STAT4/6 genes were amplified by PCR and T-A was cloned with pMD19-T simple vector and then was cloned into yeast expression vector pGADT7 cut with incision enzymes and treated with CIAP. The yeast expression vector pGADT7 was identified by enzyme cutting and sequencing. The yeast expression plasmids pGADT7-STAT4/6 were transformed into AH109 yeast cells and the expression of the STAT4/6 fusion proteins was detected by Western blot. Their toxicity and self-activation were also detected. RESULTS: Mouse STAT4/6 genes were successfully amplified and cloned into pMD19-T simple vector and pGADT7. Sequencing analysis revealed that both plasmids met the design of the study. The yeast expression plasmids pGADT7-STAT4/6 were successfully transformed into AH109 yeast cells, without toxicity or self-activation. The expression of STAT4/6 fusion proteins was confirmed by Western blot. CONCLUSION: The yeast expression plasmids pGADT7-STAT4/6 are successfully constructed and can be applied in the detection of their interaction with other proteins.

Vitamin A deficiency and wheezing.

BACKGROUND: Vitamin A deficiency may increase the responsiveness of the respiratory tract and increase the risk of respiratory tract infection, resulting in airway obstruction and wheezing. This study aimed to investigate the relation between vitamin A deficiency and infant wheezing. METHODS: Three ml venous blood samples were collected from 331 hospitalized children who suffered from wheezing to determine the serum vitamin A concentration and the relationship between vitamin A and some causative factors of wheezing. RESULTS: The severity of vitamin A deficiency was related to the course of wheezing. In the persistent wheezing group, 14 patients (34.1%) were diagnosed as having severe vitamin A deficiency and 16 patients (39%) having moderate vitamin A deficiency; among the acute wheezing group, 18 patients (16.4%) were diagnosed as having severe vitamin A deficiency and 32 patients (29%) having moderate vitamin A deficiency. Comparison of the two groups revealed that there was a significantly higher rate of moderate and severe vitamin A deficiency in the persistent wheezing group than in the acute wheezing group (P<0.01). The severity of vitamin A deficiency was related to the infants' wheezing severity. Severe vitamin A deficiency was found in 24 patients (47%) in the severe wheezing group and 8 (8%) in the mild and moderate wheezing groups. The rate of severe vitamin A deficiency was significantly higher in patients with severe wheezing than in those with mild and moderate wheezing (P<0.01). CONCLUSIONS: Serum vitamin A deficiency could be commonly found in infants with wheezing. The severity of vitamin A deficiency might be related to the course of wheezing and the infants' wheezing severity.