Mycoplasma Pneumoniae Pneumonia Children Research Articles

Clinical profiles of Mycoplasma pneumoniae pneumonia in children with different pleural effusion patterns: a retrospective study

BackgroundThe clinical significance of the presence or absence of Mycoplasma pneumoniae (MP) in pleural effusion in Mycoplasma pneumoniae pneumonia (MPP) children has not yet been elucidated. Herein, we investigated the clinical implication of pleural fluid MP positive in children with MPP.MethodsA total of 165 MPP children with pleural effusion requiring thoracocentesis were enrolled in this study. They were subsequently divided into two groups according to the presence or absence of MP in pleural effusion, namely positive group (n = 38) and negative group (n = 127). Information on their clinical manifestations, laboratory findings, radiological characteristics and treatment modalities was retrospectively collected from medical chart reviews.ResultsThe length of hospitalization (15.00 (10.75–19.25) vs. 11.00 (9.00–14.00) days, p=0.001) and total course of illness (23.00 (18.00–28.00) vs. 20.00 (17.00–24.00) days, p=0.010) were significantly longer in the positive group than in the negative group. The occurrence of pericardial effusion (23.7% vs. 7.9%, p=0.017), atelectasis (73.7% vs. 53.5%, p=0.027) and necrotizing pneumonia (23.7% vs. 7.9%, p=0.017) were more frequent in the positive group compared to the negative group. The levels of neutrophil percentages (82.35% (75.40%-85.78%) vs. 72.70% (64.30%-79.90%), p<0.001), C-reactive protein (CRP) (71.12 (37.75–139.41) vs. 31.15 (13.54–65.00) mg/L, p<0.001), procalcitonin (PCT) (0.65 (0.30–3.05) vs. 0.33 (0.17–1.13) ng/ml, p=0.005), serum lactate dehydrogenase (LDH) (799.00 (589.00–1081.50) vs. 673.00 (503.00–869.00) U/L, p=0.009), D-dimer (6.21 (3.37–16.11) vs. 3.32 (2.12–6.62) mg/L, p=0.001) on admission were significantly higher in the positive group than in the negative group. These pronounced differences significantly contributed to the identification of MPP with MP positive pleural effusion, as evidenced by the ROC curve analysis. Marked elevations in adenosine deaminase (49.25 (36.20–60.18) vs. 36.20 (28.10–46.50) U/L, p<0.001) and LDH levels (2298.50 (1259.75–3287.00) vs. 1199.00 (707.00–1761.00) U/L, p<0.001) were observed in pleural fluid of the positive group when compared to the negative group. Meanwhile, the number of patients on low molecular weight heparin (LMWH) therapy (9 (23.7%) vs. 12 (9.4%), p=0.028) was higher in the positive group. Multivariate logistic regression analysis revealed that D-dimer > 7.33 mg/L was significantly associated with the incidence of MP positive pleural effusion in MPP (OR=3.517).ConclusionsThe presence of MP in pleural fluid in MPP children with pleural effusion indicated a more serious clinical course. D-dimer > 7.33 mg/L was a related factor for MP positive pleural effusion in MPP. The results of the present study would help in the creation of a therapeutic plan and prediction of the clinical course of MPP in children.

Clinical efficacy of macrolide antibiotics in mycoplasma pneumoniae pneumonia carrying a macrolide-resistant mutation in the 23 S rRNA gene in pediatric patients

BackgroundThe global prospective surveillance data showed the re-emergence of mycoplasma pneumoniae pneumonia (MPP) in Europe and Asia after the coronavirus disease 2019 pandemic. We sought to observe the effect of macrolide antibiotics in the treatment of MPP carrying a macrolide-resistant mutation gene and the potential of targeted next-generation sequencing (tNGS) as a front-line diagnostic in MPP patients.MethodsThe baseline characteristics of 91 children with MPP hospitalized from January to October 2023 were retrospectively analyzed. They were divided into two groups according to whether carrying the macrolide-resistant mutation or not. The logistic and linear regression analyses were used to determine whether the mutation was a standalone predictive predictor of the duration of fever and hospital length of stay.ResultsFirst, no patients had a fever for ≥ 7 days after macrolide treatment. But length of stay and hormone concentration were significantly different between the two groups (P < 0.05). There were also no statistical association between the mutation and the duration of fever and hospital length of stay.ConclusionMacrolides can be administered to MPP children carrying a macrolide-resistant mutation. tNGS can be seen as a front-line diagnostic in MPP.

Construction of a predictive model for performing bronchoalveolar lavage in children with Mycoplasma pneumoniae pneumonia and pulmonary consolidation

To investigate the risk factors for performing bronchoalveolar lavage (BAL) in children with Mycoplasma pneumoniae pneumonia (MPP) and pulmonary consolidation, and to construct a predictive model for performing BAL in these children. A retrospective analysis was performed for the clinical data of 202 children with MPP who were hospitalized in the Department of Pediatrics, Changzhou No. 2 People's Hospital Affiliated to Nanjing Medical University, from August 2019 to September 2022. According to whether BAL was performed, they were divided into BAL group with 100 children and non-BAL group with 102 children. A multivariate logistic regression analysis was used to identify the risk factors for performing BAL in MPP children with pulmonary consolidation. Rstudio software (R4.2.3) was used to establish a predictive model for performing BAL, and the receiver operator characteristic (ROC) curve, C-index, and calibration curve were used to assess the predictive performance of the model. The multivariate logistic regression analysis demonstrated that the fever duration, C-reactive protein levels, D-dimer levels, and presence of pleural effusion were risk factors for performing BAL in MPP children with pulmonary consolidation (P<0.05). A nomogram predictive model was established based on the results of the multivariate logistic regression analysis. In the training set, this model had an area under the ROC curve of 0.915 (95%CI: 0.827-0.938), with a sensitivity of 0.826 and a specificity of 0.875, while in the validation set, it had an area under the ROC curve of 0.983 (95%CI: 0.912-0.996), with a sensitivity of 0.879 and a specificity of 1.000. The Bootstrap-corrected C-index was 0.952 (95%CI: 0.901-0.986), and the calibration curve demonstrated good consistency between the predicted probability of the model and the actual probability of occurrence. The predictive model established in this study can be used to assess the likelihood of performing BAL in MPP children with pulmonary consolidation, based on factors such as fever duration, C-reactive protein levels, D-dimer levels, and the presence of pleural effusion. Additionally, the model demonstrates good predictive performance.

Immune response plays a role in Mycoplasma pneumoniae pneumonia.

Mycoplasma pneumoniae (MP) is a major pathogen of community-acquired pneumonia in children. However, the specific pathogenesis of the progression of Mycoplasma pneumoniae pneumonia (MPP) is unclear. We aimed to reveal the landscape of microbiota and the host immune response in MPP. This self-controlled study analyzed the microbiome and transcriptome of bronchoalveolar lavage fluid (BALF) from the severe side (SD) and opposite side (OD) of 41 children with MPP from January to December 2021 and revealed the differences of the peripheral blood neutrophil function among children with mild MPP, severe MPP, and healthy children through transcriptome sequencing. The MP load or the pulmonary microbiota had no significant difference between the SD group and OD group, and the deterioration of MPP was related to the immune response, especially the intrinsic immune response. The immune response plays a role in MPP, which may inform treatment strategies for MPP.

Clinical characteristics and serum inflammatory markers of community-acquired mycoplasma pneumonia in children.

To compare the demographic and clinical features, laboratory and imaging findings in mycoplasma pneumoniae pneumonia (MPP) children with non-MPP (NMPP) children and general MPP (GMPP) children with refractory MPP (RMPP) children and analysis the relationship with the severity of disease. The study included 265 children with MPP and 230 children with NMPP in the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University from 2020 to 2021. The children with MPP included RMPP (n = 85) and GMPP (n = 180). Demographic and clinical characteristics, laboratory and imaging findings of all children were measured as baseline data within 24 h after admission and the differences between MPP and NMPP, RMPP and GMPP patients were compared. ROC curves were used to evaluate the diagnostic and predictive value of different indicators for RMPP. Fever duration and hospital stay in children with MPP were longer than those with NMPP. The number of patients with imaging features of pleural effusion, lung consolidation and bronchopneumonia in MPP group was significantly higher than that in NMPP group. Compared with NMPP group, the levels of C-reactive protein (CRP), procalcitonin (PCT), serum amyloid A (SAA), erythrocyte sedimentation rate (ESR), lactic dehydrogenase (LDH), prothrombin time (PT), fibrinogen (FIB) and D-dimer and inflammatory cytokines (interleukin [IL]-6, IL-8, IL-10 and IL-1β) in MPP group were significantly higher (P < 0.05). The clinical symptoms and pulmonary imaging findings were more severe in RMPP group. The levels of white blood cell (WBC), CRP, PCT, SAA, ESR, alanine aminotransferase (ALT), LDH, ferritin, PT, FIB, D-dimer and inflammatory cytokines in RMPP group were higher than those in GMPP group. There was no significant difference in the level of lymphocyte subsets between the RMPP and GMPP group. IL-6, IL-10, LDH, PT, D-dimer and lung consolidation were independent risk factors for RMPP. IL-6 levels and LDH activity were good predictors of RMPP. In conclusion, there were differences in clinical characteristics and serum inflammatory markers between MPP group and NMPP group, RMPP group and GMPP group. IL-6, IL-10, LDH, PT and D-dimer can be used as predictive indicators for RMPP.

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

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

Correlation between Mycoplasma pneumoniae drug resistance and clinical characteristics in bronchoalveolar lavage fluid of children with refractory Mycoplasma pneumoniae pneumonia

BackgroundTo investigate the resistance-gene mutation of Mycoplasma pneumoniae (MP) in the bronchoalveolar lavage fluid of children with Mycoplasma pneumoniae pneumonia (MPP) and the clinical characteristics of refractory Mycoplasma pneumoniae pneumonia (RMPP) correlation.MethodsForty-eight children with MPP were selected and placed in RMPP and non-RMPP groups based on their clinical status – whether they had worsening clinical symptoms, persistent fever and a worsening lung image. They were also separated into drug-resistance gene mutation and non-mutated groups using nucleic acid detection. The participants’ data were collected on high-sensitivity C-reactive protein and MP-DNA loads, fever time, hospitalisation time, macrolide antibiotic application time and fever regression time after application. The differences in imaging manifestations were determined by using multivariate logistic regression to analyse the clinical characteristics of RMPP. Additionally, the correlation between drug-resistance gene mutations and the clinical characteristics of RMPP was summarised.ResultsAmong the 48 MPP children, 31 (64.6%) had A2063G and/or A2064G gene mutation, 31 (64.6%) had RMPP and 23 (74.2%) had drug-resistance gene mutation. The children in the drug-resistance gene mutation group had higher high-sensitivity C-reactive protein and MP-DNA loads, longer fever time, hospitalisation time, macrolide antibiotic application time, fever regression time after application and extrapulmonary complications. There were more symptoms and more severe changes under bronchoscopy. The difference was statistically significant (P < 0.05). Logistic multivariate regression analysis showed that the mutation of drug-resistance genes had no significant correlation with RMPP.ConclusionThe mutation rate of drug-resistance genes in children with MPP is high, the inflammatory index and MP-DNA load are high, the course of the disease is long, and the changes under bronchoscopy are severe. The occurrence of RMPP is not only determined by drug-resistance genes but may also be the result of a combination of factors.

High Expression of MUC5AC, MUC5B, and Layilin Plays an Essential Role in Prediction in the Development of Plastic Bronchitis Caused by MPP.

Plastic bronchitis (PB) is a rare respiratory condition which can result in severe respiratory complications such as respiratory failure and death. Mycoplasma pneumoniae infection is a main etiology cause of plastic bronchitis. However, the pathogenesis of plastic bronchitis complicated by Mycoplasma pneumoniae pneumonia (MPP) has not yet been fully elucidated. Our article aims to explore biomarkers for early prediction of MPP cases complicated with plastic bronchitis. We utilized a protein chip to screen for significantly different proteins among the groups of healthy, general Mycoplasma pneumoniae pneumonia (GMPP) and refractory Mycoplasma pneumoniae pneumonia (RMPP) patients, where layilin exhibited a potent change across biology information technology. Next, we demonstrated the high expression of MUC5AC, MUC5B, and layilin in bronchoalveolar lavage fluid (BALF) of MPP cases complicated with plastic bronchitis. Further study suggested that the level of layilin had a positive correlation with both MUC5AC and MUC5B. A receiver operating characteristic (ROC) analysis was performed to assess the diagnostic values of MUC5AC, MUC5B, and layilin in MPP cases with PB. Data show that the three indicators have similar diagnostic ability for MPP children with plastic bronchitis. Then, we used different concentrations of community-acquired respiratory distress syndrome (CARDS) toxin or lipid-associated membrane proteins (LAMPs) to simulate an in vitro experiment. The in vitro assay revealed that CARDS toxin or LAMPs induced A549 cells to secrete MUC5AC, MUC5B, layilin, and proinflammatory factors. These findings suggest that MUC5AC, MUC5B, and layilin are correlated with MPP. The high expression of MUC5AC, MUC5B, and layilin play an essential role in prediction in the development of plastic bronchitis caused by MPP. The high expression of MUC5AC, MUC5B, and layilin may be relevant to the severity of illness.

Intestinal bacteria flora changes in patients with Mycoplasma pneumoniae pneumonia with or without wheezing

Mycoplasma pneumoniae (MP) infection is a common cause of community-acquired pneumonia in children. Furthermore, many children with Mycoplasma pneumoniae pneumonia (MPP) have recurrent wheezing and reduced small airway function after their clinical symptoms have resolved, eventually leading to asthma. MPP can trigger immune disorders and systemic inflammatory responses. Hence, the intestine is the largest immune organ of the body. Therefore, we sought to investigate whether the alteration of intestinal flora is correlated with the development of wheezing in children with MPP. We collected 30 healthy children as group A, 50 children with nonwheezing MPP as group B, and 50 children with wheezing MPP as group C. We found that the percentage of eosinophil cells (EC) was significantly higher in group C than that in group B for routine blood tests and serum inflammatory factors. The serum cytokines, including IL-4, IL-17, TNF-α, and TGF-β, were significantly higher in group C than in group B. In addition, the level of IL-10 was significantly lower in group C than in group B. The distribution characteristics of intestinal flora strains in children with MPP were detected by sequencing of 16S rRNA gene amplicon sequencing. There were differences in the abundance of intestinal flora between children with MPP and healthy children, with lower abundance of Ruminococcus flavefaciens, Clostridium butyricum, Lactobacillus, and Bifidobacterium in the intestine of children with MPP compared to healthy children. The abundance of Ruminococcus flavefaciens and Clostridium butyricum was significantly lower in the intestine of children with wheezing MPP compared to children without wheezing MPP. In the correlation analysis between children with MPP and inflammatory factors, Ruminococcus flavefaciens was found to be negatively correlated with IL-17. Clostridium butyricum was negatively correlated with L-4, IL-17, TNF-α, and TGF-β; however, it positively correlated with IL-10. Thus, it was concluded that alterations in intestinal flora play a crucial role in the immune response to MPP, where a significant decline in intestinal Ruminococcus flavefaciens and Clostridium butyricum leads to an exacerbation of the inflammatory responses, which may promote the development of children with wheezing MPP.

Exhausted and Apoptotic BALF T Cells in Proinflammatory Airway Milieu at Acute Phase of Severe Mycoplasma Pneumoniae Pneumonia in Children.

Severe mycoplasma pneumoniae pneumonia (MPP) in children presents with serious clinical complications. Without proper and prompt intervention, it could lead to deadly consequences. Dynamics of the inflammatory airway milieu and activation status of immune cells were believed to be the hallmark of the pathogenesis and progress of the disease. In this study, by employing the T-cell sorting and mRNA microarray, we were able to define the main feature of the chemokine/cytokine expression and the unique characteristics of T cells in the bronchoalveolar lavage fluid (BALF) from severe MPP patients at acute phase. Our study for the first time delineated the molecular changes in isolated BALF T cells in severe MPP children with respect to the cytokine/chemokine expression, cell activation, exhaustion, and apoptosis. By comparing the BALF aqueous expression of cytokines/chemokines with that in sorted T cells, our data give a preliminary clue capable of finishing out the possible cell source of the proinflammatory cytokines/chemokines from the BALF mixture. Meanwhile, our data provide a distinctively pellucid expression profile particularly belonging to the isolated BALF T cells demonstrating that in the inflammatory airway, overactivated T cells were exhausted and on the verge of apoptotic progress.

Correlations of Different Serological Parameters with the Severity and Prognosis of Pneumonia in Children Infected with Mycoplasma Pneumoniae.

As a common pediatric respiratory disease, Mycoplasma pneumoniae pneumonia (MPP) accounts for 20 - 30% of acquired pneumonia in children, with a rising morbidity rate annually. We aimed to explore the correlations of different serological parameters with the severity and prognosis of MPP children. A total of 108 MPP children were divided into severe group (n = 58) and mild group (n = 50). The serum levels of triglycerides, HDL-C, LDL-C, erythrocyte sedimentation rate (ESR), D-dimer (DD), lactate dehydrogenase (LDH), interleukin-6 (IL-6), galectin-3 (Gal-3), homocysteine (Hcy), and procalcitonin (PCT) were measured. Receiver operating characteristic (ROC) curves were plotted to analyze their predictive values for poor prognosis. They were followed up for 6 months and assigned into good and poor prognosis groups. Multivariate logistic regression analysis was performed to explore the serological parameters affecting prognosis. A prediction model was established. In acute and recovery phases, the levels of ESR, DD, LDH, IL-6, Gal-3, Hcy, and PCT in the severe group were significantly higher than those in the mild group (p < 0.05). Prediction combining various serological parameters had the highest value for poor prognosis. ESR, DD, LDH, IL-6, Gal-3, Hcy, and PCT levels were independent risk factors. The concordance index of the nomogram model established using these factors was 0.745 (95% CI: 0.684 - 0.830). The area under the ROC curve was 0.726 (95% CI: 0.701 - 0.815). The predicted probability of the model was consistent with the actual one, showing high accuracy. Serum levels of ESR, DD, LDH, IL-6, Gal-3, Hcy, and PCT are closely correlated with the severity and prognosis of MPP children, which provide references for prognostic evaluation. Prediction combining these indices is more valuable than that using a single index.

Analysis of Clinical Characteristics and Risk Factors of Plastic Bronchitis in Children With Mycoplasma pneumoniae Pneumonia.

Objective: To analyze the clinical characteristics of plastic bronchitis (PB) in children with Mycoplasma pneumoniae pneumonia (MPP) in order to explore its risk factors.Methods: A retrospective analysis was performed in MPP children receiving bronchoscopy admitted to department of respiratory medicine in Shanghai Children's Hospital from January 2018 to December 2020. According to the bronchoscopic findings, the patients were divided into PB group and non-PB group. The clinical manifestations, laboratory examination, etiology, treatment methods and outcomes of the children were analyzed. Logistic regression was used to analyze the risk factors for PB in children with MPP.Results: A total of 296 children with MPP were enrolled in the study, including 42 (14.2%) children in the PB group and 254 (85.8%) children in the non-PB group. There was no difference in the ratios of gender, age, proportion of fever, cough, wet rales, and wheezing rales between the two groups (P > 0.05). The univariate analysis showed that there were significant differences between the PB group and the non-PB group in LDH, D-dimer, CD3+CD4+(%), CD3+CD4+/CD3+CD8+, CD3 count, CD4 count, CD8 count, complement 3, IL8, IL-1β, IL-2, IL-10 (P < 0.05). The multivariate logistic regression analysis showed that fever duration > 12 d, IL-8 > 2,721.33 pg/ml, LDH > 482 U/L and complement 3 <1.02 g/L were independent risk factors for PB in children with MPP.Conclusions: Children with PB caused by MPP have protracted fever, a strong inflammatory response and immune function disturbance.

Evaluation on blood coagulation and C-reactive protein level among children with mycoplasma pneumoniae pneumonia by different chest imaging findings.

Mycoplasma pneumoniae infection may induce a systemic hypercoagulable abnormality, like organ embolism and infarction. Indexes of blood coagulation and C-reactive protein (CRP) have been reported different between healthy people and mycoplasma pneumoniae pneumonia (MPP) patients, but this difference in MPP patients with different chest imaging findings has rarely been reported.We performed a retrospective study of 101 children with MPP and 119 controls, combined with radiological examination and blood tests, to compare the blood coagulation and CRP level among MPP children with different chest imaging findings.For the MPP children with different chest imaging findings, there were significant differences in CRP, fibrinogen (FIB) and D-dimer (D-D) levels among subgroups (P = .004, P = .008 and P < .001 respectively). The CRP level in group of interstitial pneumonia was significantly higher than that in groups of bronchopneumonia and hilar shadow thickening (P = .003 and P = .001 respectively). And the FIB and D-D values in group of lung consolidation were significantly higher than that in the other 3 groups (all P < .05). When compared with controls, the white blood cell, CRP, FIB, and D-D levels in MPP children were significantly higher, and the activated partial thromboplastin time and thrombin time levels were significantly lower (all P < .05).Our results showed that CRP level changed most significantly in group of interstitial pneumonia, whereas FIB, D-D levels changed most significantly in the lung consolidation group.

Clinical features of children with Mycoplasma pneumoniae pneumonia and peripheral lymphocytopenia

OBJECTIVE To study the clinical features of children with Mycoplasma pneumoniae pneumonia (MPP) and peripheral lymphocytopenia. METHODS A total of 310 MPP children who were hospitalized and underwent bronchoalveolar lavage from June 2018 to June 2019 were enrolled and divided into two groups: simple MPP group with 241 children (without peripheral lymphocytopenia) and MPP + peripheral lymphocytopenia group with 69 children. The two groups were compared in terms of clinical data and treatment outcome. RESULTS Compared with the simple MPP group, the MPP + peripheral lymphocytopenia group had significantly longer duration of fever and length of hospital stay and significant increases in C-reactive protein, lactate dehydrogenase, and Mycoplasma pneumoniae DNA copies in bronchoalveolar lavage fluid (P < 0.05). Compared with the simple MPP group, the MPP + peripheral lymphocytopenia group had significantly higher incidence rates of intrapulmonary consolidation, extrapulmonary complications, and serious lesions under bronchoscopy (erosion or sputum bolt) and a significantly higher proportion of patients with severe MPP (P < 0.05). CONCLUSIONS Children with MPP and peripheral lymphocytopenia tend to have more severe immunologic injury. Peripheral blood lymphocyte count may be used to evaluate the severity of MPP.

Dynamic change of Mycoplasma pneumoniae pneumonia in hospitalized children in a general hospital: a 3-year retrospective analysis

BackgroundThe epidemiology and economic burden of hospitalized community-acquired pneumonia (CAP) children due to MP is still poorly understood. This study aimed to investigate the dynamic changes of Mycoplasma pneumoniae pneumonia (MPP) in children in a general hospital.MethodsA total of 2011 CAP children aged 1–16 years hospitalized at Peking University Third Hospital from 2017 to 2019 were enrolled by cross-sectional study for the retrospective analysis of the clinical data mainly including seasonal distribution of MPP, hospital stay, severity, complications, use of flexible bronchoscopy, and hospitalization costs. The dynamic changes of CAP and MPP children within 3 consecutive years and the differences between the MPP group and non-MPP groups were compared.ResultsThe proportion of CAP children among hospitalized children was 32.4%, 38.5%, and 39.5% in 2017, 2018, and 2019, respectively, showing an upward trend (P<0.05).The prevalence rate of MPP was highest in the third quarter (30.2%) and the fourth quarter (39.2%) and lowest in the second quarter (13.2%) (χ2=51.8, P<0.05). Compared with the non-MPP group, the MPP group had significantly higher incidence of severe pneumonia (19.4% vs. 12.0%, χ2=20.99), incidence of complications (16.1% vs. 6.5%, χ2=48.24), proportion of patients undergoing flexible bronchoscopy (38.4% vs. 9.0%, χ2=252.79), and hospitalization costs (all P<0.05), along with significantly longer hospital stay (6 vs. 4 days, z=−11.131). A dynamic comparison of the clinical characteristics of MPP in 3 years showed that the number of children with MPP increased significantly in preschoolers in 2018 (37.3%) and in school-aged or older children in 2019 (53%) (P<0.05). MPP peaks occurred in August 2018 and November 2019. The total hospitalization costs, examination fees, and non-medication treatment costs increased significantly (the z values were 35.24, 46.79, and 9.64, respectively; P<0.05) year by year among MPP children; there was no significant difference in the medication cost over these 3 years (z=4.81, P>0.05).ConclusionsThe proportions of severe pneumonia, complications, and use of flexible bronchoscopy as well as the hospitalization days and costs are higher in MPP children. General hospitals should develop integrated clinical quality control programs for MPP children, so as to optimize the allocation of medical resources.

Impact of Epstein-Barr virus coinfection in Mycoplasma pneumoniae pneumonia.

Mycoplasma pneumoniae (MP) is one of the most common pathogens of respiratory infection in children, while Epstein-Barr virus (EBV) infection is usually subclinical in immunocompetent children. Although single MP infection is common enough, MP and EBV coinfection have received little attention. Especially, the pathogenic role of EBV in lung when coinfection with MP, has not been clarified. The purpose of this study was to investigate the impact of EBV on MP pneumonia (MPP) in hospitalized children. We retrospectively reviewed the clinical data of MPP children who underwent screening for EBV by polymerase chain reaction in bronchoalveolar lavage fluid during hospitalization in 2014. Of total 147 patients, 68 patients were in the MP group and 79 were in the MP/EBV coinfection group. We found longer fever duration and higher CRP, IgA, IgG, interleukin-2 (IL-2), percentage of peripheral neutrophils levels, higher incidence of pulmonary consolidation and percentage of refractory MPP in coinfection group, when compared to those in MP group. In ROC curve analysis, IL-2 was useful for differentiating patients with coinfection from those with MP infection. Logistic regression analysis showed that the IL-2 ≥ 3.35 pg/ml (OR = 3.677) was a significant predictor regarding to MP/EBV coinfection. In conclusion, coinfection of EBV and MP poses a higher risk for prolonged symptoms. IL-2 could be used as a good predictor of coinfection.

Airway microbiota in children with bronchial mucus plugs caused by Mycoplasma pneumoniae pneumonia.

There is increasing evidence for a role of lung microbiota in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). However, the alterations of lung microbiota in MPP with bronchial mucus plugs and its role in disease pathogenesis remain poorly understood. In this prospective observational study, we performed a longitudinal 16S rRNA-based microbiome survey on bronchoalveolar lavage (BAL) samples collected from 31 MPP with bronchial mucus plugs and 52 MPP without mucus plugs. Our study showed a clear difference in airway microbiota between MPP children with and without bronchial mucus plugs. The MPP children with mucus plugs had lower abundances of Sphingomonas and Elizabethkingia, and a high abundance of Mycoplasma compared with MPP children without mucus plugs, subsequently contributing to increased ratios of Mycoplasma to Sphingomonas and Mycoplasma to Elizabethkingia. Children's age, fever time and serum cytokine levels were associated with airway microbiota alteration. Furthermore, significant correlations between bacterial genus abundances were found in MPP children with mucus plugs. Our results suggest an impact of airway microbiota on the clinical course of MPP in children, deserving further investigations.

High Mycoplasma pneumoniae loads and persistent long-term Mycoplasma pneumoniae DNA in lower airway associated with severity of pediatric Mycoplasma pneumoniae pneumonia

BackgroundAn increased number of refractory mycoplasma pneumoniae (MP) pneumonia (MPP) cases have been reported. However the duration of MP infection in lower airway and the course of anti-MP treatment remains unclear.MethodsWe retrospectively reviewed the medical records of 94 MPP children. Patients were classified into two groups. The long-term group (Group LT) was defined as bronchoalveolar lavage fluid (BALF) remained MP-positive by PCR after 30 days of the disease course. The non-long-term group (Group NLT) was defined as BALF became MP-negative by PCR within 30 days of disease and patients who only needed one bronchoscopy lavage therapy. MP loads, clinical outcomes were analyzed along with other clinical measurements.ResultsThe average levels of inflammatory markers such as C reactive protein and lactate dehydrogenase in Group LT were significantly higher than those in Group NLT. Airway and lung damage in Group LT were more severe than Group NLT. 28 patients developed necrotizing pneumonia and 8 patients developed pulmonary embolism in Group LT. Mean maximum MP loads in BALF were 107.46 ± 0.93 and 104.86 ± 0.93 in Groups LT and NLT, respectively. There was persistent MP DNA in Group LT, even lasted for 120 days. One severe MPP patient in Group LT had MP-associated bloodstream infection. After 3 months of follow-up, chest imaging revealed incomplete absorption of pulmonary consolidation in 33 patients of Group LT [including 13 airway obliterans (AO) patients] and in 7 patients of Group NLT (including 2 AO patients).ConclusionMP loads of BALF were associated with the subsequent duration of MP DNA in lower airway. High MP loads and persistent long-term MP DNA in lower airway were associated with severity of pediatric MPP.

Cytokine signatures associate with disease severity in children with Mycoplasma pneumoniae pneumonia

Host immune response may be involved in the pathogenesis of children Mycoplasma pneumoniae pneumonia (MPP). In the current study, we investigated the alterations of cytokines levels among control, mild MPP and severe MPP children to determine whether cytokine signatures associate with MPP and correlate with disease severity. We measured 13 cytokines in bronchoalveolar lavage fluid (BALF) of 88 children with MPP and 26 children with foreign body aspiration (FB) using a Luminex system. Linear discriminant analyses were performed to develop predictive models of mild MPP and severe MPP on these children. We observed nearly complete separations of severe MPP group, mild MPP group and control group in linear discriminant analyses. Eleven cytokines significantly increased in children with MPP, and seven cytokines had statistically significant upward linear trends correlated with MPP severity. In addition, compared to control group, both IFNγ/IL4 ratio and IFNγ/IL13 ratio increased in mild MPP and severe MPP groups. Our results suggest that children MPP can alter BALF cytokines signatures which associate with disease severity and can be characterized by a distinct airway molecular phenotype that has elevated Th1/Th2 ratios.

Distribution and Expression of IL-17 and Related Cytokines in Children with Mycoplasma pneumoniae Pneumonia.

The pathogenesis of Mycoplasma pneumoniae pneumonia (MPP), specifically the local immune responses in the lungs, is poorly understood. In this study, flow cytometry was used to analyze IL-17 and related cytokines in plasma and bronchoalveolar lavage fluid (BALF) samples from 18 and 30 pediatric patients with general MPP (GMPP) and refractory MPP (RMPP), respectively. The levels of IL-1Ra, IL-6, IL-8, IL-17, and TNF-α were significantly elevated in the BALF of MPP children compared to the plasma (P < 0.01). Although the plasma IL-6 levels in the children with RMPP were higher than those in the children with GMPP (P < 0.05), the IL-17 levels showed the opposite trend (P < 0.05). The children with RMPP had significantly higher BALF levels of IL-8, IL-17, and TNF-α than the children with GMPP (P < 0.05), and the elevated levels of IL-17 correlated with the increased focal size of the lung lesions (P < 0.05). The elevated levels of IL-17 and related cytokines in the BALF samples could indicate that the local inflammatory response should be distinguished from the systemic inflammatory response in children with MPP. Moreover, RMPP might involve an aggravated inflammatory progression at the site of infection. The levels of IL-17 might correlate with the extent and severity of the lung lesions in MPP.