Objective:To summarize the clinical features of Chlamydia pneumoniae pneumonia (CPP) in children. Methods:Case series study. Clinical data of 10 children with CPP hospitalized in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University from January 2019 to August 2024 were retrospectively collected, including general information, clinical manifestations, chest imaging, laboratory examination and treatment. The clinical features and prognosis were summarized.Results:Among the 10 children with CPP, 7 were male and 3 were female. The age of onset was 11.2 (10.3, 13.1) years. The course were 17 (7, 23) days. Cough occurred in 9 cases with wet cough in 7 cases, while moderate and high fever occurred in 6 cases. Besides, chest pain occurred in 4 cases, rash and hemoptysis occurred in 1 case respectively. High density mass shadow was found in 7 cases chest CT imaging, accompanied by air bronchogram sign, surrounded by halo sign, 6 cases of which were distributed under the pleura, while patchy consolidation in the remaining 3 cases. Pulmonary embolism was present in 2 cases. Among the 10 children with CPP, bilateral lung involvement was found in 3 cases and unilateral lung involvement in 7 cases. The white blood cell count was 10.21 (7.45, 11.64)×10 9/L and the proportion of neutrophils was 0.69 (0.63, 0.71). C-reactive protein increased in 7 cases, with the level of 33 (16, 77) mg/L. D-dimer increased slightly in 3 cases (0.393, 0.396, 0.739 mg/L). Serum Chlamydia pneumoniae-IgM antibody test was positive in 6 cases. Chlamydia pneumoniae nucleic acid test by bronchoalveolar lavage fluid (BALF) next-generation sequencing was positive in 6 cases. Both serum IgM antibody and BALF nucleic acid tests were positive in 2 cases. Among the 10 children with CPP, azithromycin alone was used in 5 cases, while glucocorticoid was added in 1 case. Due to poor response to azithromycin in 4 cases, doxycycline was replaced in 3 cases and minocycline was replaced in 1 case, while glucocorticoid was added in 2 cases. Moxifloxacin combined with glucocorticoid therapy was adopted in 1 case with long course after the poor response to azithromycin and doxycycline. All patients were cured finally. Conclusions:CPP mostly occurs in elderly children. The main clinical manifestations include cough, fever and chest pain. The common chest imaging feature is subpleural high-density mass shadow with halo sign. Pulmonary embolism is present in a few cases. Nucleic acid detection and (or) serology is helpful for etiological diagnosis. Some cases need glucocorticoid therapy.

Objective:To explore the risk factors for bronchiolitis obliterans (BO) after Mycoplasma pneumoniae bronchiolitis in children. Methods:A retrospective cohort study was conducted on 122 children diagnosed with Mycoplasma pneumoniae bronchiolitis in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University, from March 2017 to December 2024. Clinical data, including general information, clinical manifestations, imaging findings, laboratory tests, and outcomes, were analyzed. Patients were divided into BO and non-BO groups based on the presence of BO. Differences between groups were assessed using Mann-Whitney U test, χ2 test, or Fisher exact test. Logistic regression and receiver operating characteristic (ROC) curve analysis were employed to identify risk factors and evaluate predictive performance. Results:Among 122 children (73 males, 49 females), the age at onset was 5.0 (2.4, 7.1) years. The BO group included 21 patients, and the non-BO group 101. The BO group exhibited significantly longer durations of persistent high fever and higher peak levels of C-reactive protein, lactate dehydrogenase, and D-dimer compared to the non-BO group (9 (7, 11) vs. 4 (2, 6) d, 19 (7, 35) vs. 10 (7, 18) mg/L, 438 (337, 498) vs. 315 (274, 351) U/L, 0.36 (0.27, 0.91) vs. 0.21 (0.15, 0.29) mg/L, U=295.00, 743.50, 463.50, 470.50, all P<0.05). The BO group also had higher proportions of resting oxygen saturation <0.95 on room air (100.0% (21/21) vs. 43.6% (44/101)), inspiratory retractions (57.1% (12/21) vs. 18.8% (19/101), χ2=11.53), and adenovirus co-infection (38.1% (8/21) vs. 5.0% (5/101)) (all P<0.05). Multivariate Logistic regression identified prolonged high fever ( OR=1.83, 95% CI 1.31-2.58, P<0.001), inspiratory retractions ( OR=10.48, 95% CI 1.72-63.85, P=0.011), and adenovirus co-infection ( OR=42.47, 95% CI 4.04-446.87, P=0.002) as independent risk factors for BO. ROC curve analysis revealed that a fever duration cutoff of 7.5 days predicted BO with 0.71 sensitivity and 0.92 specificity. Conclusions:Prolonged high fever (≥7.5 days), inspiratory retractions, and adenovirus co-infection are significant predictors of BO after Mycoplasma pneumoniae bronchiolitis in children, which are helpful for early clinical identification.

Objective:To summarize the clinical features of Chlamydia pneumoniae pneumonia (CPP) in children. Methods:Case series study. Clinical data of 10 children with CPP hospitalized in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University from January 2019 to August 2024 were retrospectively collected, including general information, clinical manifestations, chest imaging, laboratory examination and treatment. The clinical features and prognosis were summarized.Results:Among the 10 children with CPP, 7 were male and 3 were female. The age of onset was 11.2 (10.3, 13.1) years. The course were 17 (7, 23) days. Cough occurred in 9 cases with wet cough in 7 cases, while moderate and high fever occurred in 6 cases. Besides, chest pain occurred in 4 cases, rash and hemoptysis occurred in 1 case respectively. High density mass shadow was found in 7 cases chest CT imaging, accompanied by air bronchogram sign, surrounded by halo sign, 6 cases of which were distributed under the pleura, while patchy consolidation in the remaining 3 cases. Pulmonary embolism was present in 2 cases. Among the 10 children with CPP, bilateral lung involvement was found in 3 cases and unilateral lung involvement in 7 cases. The white blood cell count was 10.21 (7.45, 11.64)×10 9/L and the proportion of neutrophils was 0.69 (0.63, 0.71). C-reactive protein increased in 7 cases, with the level of 33 (16, 77) mg/L. D-dimer increased slightly in 3 cases (0.393, 0.396, 0.739 mg/L). Serum Chlamydia pneumoniae-IgM antibody test was positive in 6 cases. Chlamydia pneumoniae nucleic acid test by bronchoalveolar lavage fluid (BALF) next-generation sequencing was positive in 6 cases. Both serum IgM antibody and BALF nucleic acid tests were positive in 2 cases. Among the 10 children with CPP, azithromycin alone was used in 5 cases, while glucocorticoid was added in 1 case. Due to poor response to azithromycin in 4 cases, doxycycline was replaced in 3 cases and minocycline was replaced in 1 case, while glucocorticoid was added in 2 cases. Moxifloxacin combined with glucocorticoid therapy was adopted in 1 case with long course after the poor response to azithromycin and doxycycline. All patients were cured finally. Conclusions:CPP mostly occurs in elderly children. The main clinical manifestations include cough, fever and chest pain. The common chest imaging feature is subpleural high-density mass shadow with halo sign. Pulmonary embolism is present in a few cases. Nucleic acid detection and (or) serology is helpful for etiological diagnosis. Some cases need glucocorticoid therapy.

Objective:To explore the risk factors for bronchiolitis obliterans (BO) after Mycoplasma pneumoniae bronchiolitis in children. Methods:A retrospective cohort study was conducted on 122 children diagnosed with Mycoplasma pneumoniae bronchiolitis in Department No.2 of Respiratory Medicine of Beijing Children′s Hospital, Capital Medical University, from March 2017 to December 2024. Clinical data, including general information, clinical manifestations, imaging findings, laboratory tests, and outcomes, were analyzed. Patients were divided into BO and non-BO groups based on the presence of BO. Differences between groups were assessed using Mann-Whitney U test, χ2 test, or Fisher exact test. Logistic regression and receiver operating characteristic (ROC) curve analysis were employed to identify risk factors and evaluate predictive performance. Results:Among 122 children (73 males, 49 females), the age at onset was 5.0 (2.4, 7.1) years. The BO group included 21 patients, and the non-BO group 101. The BO group exhibited significantly longer durations of persistent high fever and higher peak levels of C-reactive protein, lactate dehydrogenase, and D-dimer compared to the non-BO group (9 (7, 11) vs. 4 (2, 6) d, 19 (7, 35) vs. 10 (7, 18) mg/L, 438 (337, 498) vs. 315 (274, 351) U/L, 0.36 (0.27, 0.91) vs. 0.21 (0.15, 0.29) mg/L, U=295.00, 743.50, 463.50, 470.50, all P<0.05). The BO group also had higher proportions of resting oxygen saturation <0.95 on room air (100.0% (21/21) vs. 43.6% (44/101)), inspiratory retractions (57.1% (12/21) vs. 18.8% (19/101), χ2=11.53), and adenovirus co-infection (38.1% (8/21) vs. 5.0% (5/101)) (all P<0.05). Multivariate Logistic regression identified prolonged high fever ( OR=1.83, 95% CI 1.31-2.58, P<0.001), inspiratory retractions ( OR=10.48, 95% CI 1.72-63.85, P=0.011), and adenovirus co-infection ( OR=42.47, 95% CI 4.04-446.87, P=0.002) as independent risk factors for BO. ROC curve analysis revealed that a fever duration cutoff of 7.5 days predicted BO with 0.71 sensitivity and 0.92 specificity. Conclusions:Prolonged high fever (≥7.5 days), inspiratory retractions, and adenovirus co-infection are significant predictors of BO after Mycoplasma pneumoniae bronchiolitis in children, which are helpful for early clinical identification.

Objective·To develop physiologically based pharmacokinetic(PBPK)models specifically designed for the Chinese population by utilizing the combination of clozapine and fluvoxamine as a case,and predict the drug-drug interaction(DDI)associated with the combination medication of clozapine,ultimately optimizing the dosage of clozapine.Methods·By obtaining the physicochemical parameters,absorption,distribution,metabolism,excretion(ADME)-related parameters,and physiologically relevant parameters of the Chinese population through literature and pharmacology-related databases,PBPK models for the clozapine and fluvoxamine were constructed by using PK-Sim? software.The models' accuracy was evaluated by comparing predicted values of the area under the curve(AUC)and peak concentration(Cmax)to observed data,using the mean percentage error(MPE)and mean absolute percentage error(MAPE)as evaluation indicators.The models were validated against real-world plasma drug concentration data.Additionally,combining the inhibitory effect of fluvoxamine on clozapine,models for the combination therapy of clozapine and fluvoxamine were developed to predict the pharmacokinetic changes of clozapine.The presence of clinically significant DDI was determined by using the 90%confidence interval of the AUC ratio(AUCR)or Cmax ratio(CmaxR)as evaluation metrics,with a non-effect boundary set at 80%?125%.The pharmacokinetic changes of clozapine upon co-administration with fluvoxamine based on PBPK models were quantified,and a dosage optimization for clozapine was developed.Results·The constructed model of clozapine and fluvoxamine was considered accurate if the absolute value of the MPE was≤10%and the MAPE was<25%during validation,indicating that the predicted concentration-time curves were accurate.The PBPK model for the co-administration of clozapine and fluvoxamine was able to accurately predict pharmacokinetic parameters if the ratio of predicted AUC to observed AUC was within 1.25.The prediction of PBPK model for the co-administration showed that the 90%confidence intervals for AUCR and CmaxR of the combination therapy of clozapine and fluvoxamine were not entirely within the ineffective effect boundary,indicating a clinically significant DDI when these two drugs were used concomitantly.Moreover,the dose optimization according to the PBPK models indicated that when subjects were co-administered with clozapine and fluvoxamine,reducing the dose of clozapine to 50%of the original dose could maintain the exposure levels of clozapine consistent with monotherapy.Conclusion·The established PBPK model can effectively simulate the impact of combination therapy on pharmacokinetic changes of clozapine,providing valuable insights for predicting potential DDI and optimizing dosage regimens.If clozapine needs to be co-administered with fluvoxamine during the treatment,clinicians should remain vigilant for clinically significant DDI and contemplate optimizing the dosage of clozapine accordingly.

Objective:To observe the expression of Galectin-7 in the serum and sputum of asthmatic children and to explore its significance in asthmatic children.Methods:The study prospectively case-control selected 183 children diagnosed with bronchial asthma at Department Ⅱ of Respiratory Medicine, National Clinical Research Center for Respiratory Diseases, Beijing Children′s Hospital of Capital Medical University. The control group consisted of 41 children with other bronchial diseases and 43 healthy children. Children in the asthma group were divided into acute and non-acute exacerbation groups. Acute exacerbation group was divided as mild acute, moderate acute and severe acute groups; non-acute exacerbation group was divided as mild persistent, moderate persistent and severe persistent groups. Children without acute exacerbation asthma in the asthma group were divided into high and low Galectin-7 groups based on median serum Galectin-7 levels. Serum and sputum were collected, Galectin-7 levels were measured using enzyme-linked immunosorbent assay. The study compared and analyzed the differences in Galectin-7 levels between children with asthma and the control groups using Mann-Whitney U test or the Kruskal-Wallis or the Chi-square test for inter-group comparisons. Results:Among 183 children, 61 cases had acute asthma exacerbation, and 122 cases had persistent asthma without acute exacerbation. The asthma group comprised 110 males and 73 females. The control group consisted of 41 children with other bronchial diseases, including 24 cases of bronchiectasis and 17 cases of obliterans bronchitis. The control group comprised 26 males and 15 females. Forty-three healthy children who underwent physical examination, including 22 males and 21 females. The levels of Galectin-7 in serum were significantly higher in children with an acute asthma exacerbation than that of healthy children (0.1 (0, 0.7) vs. 0 (0, 0.2) μg/L, Z=2.09, P=0.001). Galectin-7 levels in sputum were higher in children with an acute asthma exacerbation than that in children with other bronchial diseases (1.2 (0.1,3.7) vs. 0.4 (0.1, 1.5) μg/L, Z=2.20, P<0.001). Serum Galectin-7 levels were significantly higher in children with persistent asthma compared to children with other bronchial diseases and healthy children (0.6 (0.3, 1.2) vs. 0.1 (0, 0.5) and 0 (0, 0.2) μg/L, Z=-6.12 ,-7.63, both P<0.001), and the levels were significantly and positively correlated with asthma severity ( r=0.77, P<0.001), disease duration ( r=0.34, P=0.001), and number of previous attacks ( r=0.51, P<0.001). There were 61 children in the high-Galectin-7 group and 61 children in the low-Galectin-7 group. Children with high Galectin-7 had more asthma triggers, a greater proportion with a positive family history, more previous asthma attacks, longer duration of asthma, and higher serum total IgE levels compared to those with low Galectin-7 ( χ2=9.30, 22.46, Z=5.06, 3.57, 2.31, all P<0.05). Conclusion:The expression of Galectin-7 is found to be elevated in the serum and sputum of asthmatic children and correlated with asthma conditions.

Objective:To investigate and summarize pediatric patients with severe Mycoplasma pneumoniae pneumonia (MPP) presenting with varied clinical and chest imaging features in order to guide the individualized treatment. Methods:This was a retrospective cohort study. Medical records of clinical, imaging and laboratory data of 505 patients with MPP who were admitted to the Department Ⅱ of Respirology Center, Beijing Children′s Hospital, Capital Medical University from January 2016 to October 2023 and met the enrollment criteria were included. They were divided into severe group and non-severe group according to whether lower airway obliterans was developed. The clinical and chest imaging features of the two groups were analyzed. Those severe cases with single lobe ≥2/3 consolidation (lobar consolidation) were further divided into subtype lung-necrosis and subtype non-lung-necrosis based on whether lung necrosis was developed. Comparison on the clinical manifestations, bronchoscopic findings, whole blood C-reactive protein (CRP) and other inflammatory indicators between the two subtypes was performed. Comparisons between two groups were achieved using independent-sample t-test, nonparametric test or chi-square test. Univariate receiver operating characteristic (ROC) curve analyses were performed on the indicators such as CRP of the two subtypes. Results:Of the 505 cases, 254 were male and 251 were female. The age of the onset was (8.2±2.9) years. There were 233 severe cases, among whom 206 were with lobar consolidation and 27 with diffuse bronchiolitis. The other 272 belonged to non-severe cases, with patchy, cloudy infiltrations or single lobe <2/3 uneven consolidation or localized bronchiolitis. Of the 206 cases (88.4%) severe cases with lobar consolidation, 88 harbored subtype lung-necrosis and 118 harbored subtype non-lung-necrosis. All 206 cases (100.0%) presented with persistent high fever, among whom 203 cases (98.5%) presented with inflammatory secretion obstruction and plastic bronchitis under bronchoscopy. Of those 88 cases with subtype lung-necrosis, there were 42 cases (47.7%) with dyspnea and 39 cases (44.3%) with moderate to massive amount of pleural effusion. There were 35 cases (39.8%) diagnosed with lung embolism during the disease course, of which other 34 cases (38.6%) were highly suspected. Extensive airway mucosal necrosis was observed in 46 cases (52.3%), and the level of their whole blood CRP was significantly higher than that of subtype non-lung-necrosis (131.5 (91.0, 180.0) vs. 25.5 (12.0, 43.1) mg/L, U=334.00, P<0.001). They were regarded as subtype "lung consolidation-atelectasis-necrosis". Of those 118 cases with subtype non-lung-necrosis, 27 cases (22.9%) presented with dyspnea and none were with moderate to massive amount of pleural effusion. Sixty-five cases (55.1%) presented with plastic bronchitis and localized airway mucosal necrosis was observed in 32 cases (27.1%). They were deemed as subtype "lung consolidation-atelectasis". ROC curve analyses revealed that whole blood CRP of 67.5 mg/L on the 6-10 th day of disease course exhibited a sensitivity of 0.96, a specificity of 0.89, and an area under the curve of 0.97 for distinguishing between these two subtypes among those with lobar consolidation. Conclusions:Pediatric patients with severe MPP present with lobar consolidation or diffuse bronchiolitis on chest imaging. Those with lobar consolidation harbor 2 subtypes as "lung consolidation-atelectasis-necrosis" and "lung consolidation-atelectasis". Whole blood CRP of 67.5 mg/L can be applied as an early discriminating indicator to discriminate between these two subtypes.

Child ; Humans ; Granulomatous Disease, Chronic/complications* ; Pneumonia

Objective:To study the clinical characteristics of respiratory syncytial viral pneumonia in children aged 2 to 5 years, and pinpoint the risk factors of severe pneumonia, in order to establish a basis for early diagnosis.Methods:We performed a retrospective investigation of clinical data from 210 children aged 2-5 years, diagnosed with respiratory syncytial virus pneumonia and hospitalized in our institution from December 2017 to June 2023 of New Century International Children′s Hospital, Beijing. According to the severity of their illness, they were divided into mild group and severe group. The aim was to compare their general data and clinical characteristics and to analyze the risk factors of severe respiratory syncytial viral pneumonia.Results:Among 210 children infected with RSV pneumonia, the male to female ratio was 1.26∶1, with a peak body temperature of 39.35±0.68 ℃, an average course of fever was 5.98±2.20 days, and an average hospital stay of 7.16±2.29 days. RSV pneumonia occurred throughout the year, predominantly in spring and winter. Among the children affected, 26.19% had tachypnea, 22.38% had three concave sign, 77.14% had moist rales in the lungs, 42.86% had wheezing sounds, 22.86% had myocardial damage, 15.24% had diffuse panbronchiolitis. The result from the univariate analysis showed that there were statistically significant differences in preterm delivery, peak body temperature, length of hospital stay, tachypnea, wheezing, three concave sign, moist rale, wheezing sound, CRP, X-ray pulmonary shadow and diffuse panbronchiolitis between mild and severe groups ( P<0.05). Multivariate logistic regression analysis showed that moist rales and X-ray lung shadows were risk factors for severe RSV pneumonia. Conclusions:Importantly, certain clinical differences were observed between mild and severe cases of respiratory syncytial virus pneumonia in children aged 2 to 5 years. Moist rales and X-ray lung shadows are independent risk factors for severe respiratory syncytial viral pneumonia in children aged 2 to 5 years.

Objective:To explore the threshold of tidal breathing nasal nitric oxide (TB-nNO) in diagnosing primary ciliary dyskinesia (PCD) in children aged 3 to 5 years.Methods:Retrospective study.The TB-nNO values were examined of 165 healthy children aged 3-5 in a kindergarten in Xicheng District, Beijing, from March 27 to March 29, 2018, which were also measured in children aged 3-5 years who were diagnosed as PCD, cystic fibrosis, bronchiolitis obliterans, bronchiectasis caused by other diseases and asthma in the Second Department of Pediatric Pneumology, Beijing Children′s Hospital, Capital Medical University from January 2018 to December 2021.Relevant factors associated with TB-nNO in normal children were screened by a multiple linear regression model.The cut-off value of TB-nNO in diagnosing PCD in preschool children aged 3-5 years was determined by calculating the maximum area under the receiver operating characteristic (ROC) curve.Results:TB-nNO value in healthy children aged 3, 4 and 5 years were (94.8±36.4) nL/min, (103.3±50.7) nL/min and (106.9±61.5) nL/min, respectively.The mean TB-nNO value in 9 children with PCD was (18.9±10.8) nL/min.TB-nNO values in 49 children with asthma, 19 children with bronchiolitis obliterans, 17 children with bronchiectasis and 6 children with cystic fibrosis were (97.7±51.1) nL/min, (93.2±49.2) nL/min, (93.7±75.3) nL/min and (45.4±18.2) nL/min, respectively.Using 30 nL/min of TB-nNO as the cut-off point, the sensitivity and specificity of TB-nNO in diagnosing PCD were 88.9% (8/9) and 96.9%, respectively.The area under the ROC curve was 98.3% (95% CI: 95.3%-100.0%). Conclusions:TB-nNO value of 30 nL/min can be used as the cut-off point in the diagnosis screening of PCD in children aged 3-5 years.Its diagnostic value in this age group should be further evaluated.