Clinical Characteristics of Macrolide-Refractory Mycoplasma pneumoniae Pneumonia in Korean Children: A Multicenter Retrospective Study

[Construction of a risk prediction model for bronchiolitis obliterans in children with refractory Mycoplasma pneumoniae pneumonia]

OBJECTIVES

To explore the establishment of a risk prediction model for concurrent bronchiolitis obliterans (BO) in children with refractory Mycoplasma pneumoniae pneumonia (RMPP).

METHODS

A retrospective study included 116 RMPP children treated in the Department of Pediatrics of Xiangya Changde Hospital from June 2021 to December 2023. Eighty-one cases were allocated to the training set and thirty-five cases to the validation set based on a 7:3 ratio. Among them, 26 cases in the training set developed BO, while 55 did not. The multivariate logistic regression was used to select variable factors for constructing the BO risk prediction model. Nomograms were drawn, and the receiver operating characteristic (ROC) curve was used to assess the discriminative ability of the model, while calibration curves and Hosmer-Lemeshow tests evaluated the model's calibration.

RESULTS

Multivariate logistic regression analysis indicated that several factors were significantly associated with concurrent BO in RMPP children, including length of hospital stay, duration of fever, atelectasis, neutrophil percentage (NEUT%), peak lactate dehydrogenase (LDH), ferritin, peak C reactive protein (CRP), oxygenation index (PaO2/FiO2), ≥2/3 lung lobe consolidation, pleural effusion, bronchial mucous plugs, bronchial mucosal necrosis, and arterial oxygen partial pressure (PaO2) (P<0.05). ROC curve analysis for the training set indicated an area under the curve of 0.904 with 88% sensitivity and 83% specificity; the validation set showed an area under the curve of 0.823 with 76% sensitivity and 93% specificity. The Hosmer-Lemeshow test's Chi-square values for the training and validation sets were 2.17 and 1.92, respectively, with P values of 0.221 and 0.196, respectively.

CONCLUSIONS

The risk prediction model for BO in RMPP children based on logistic regression has good performance. Variables such as length of hospital stay, duration of fever, atelectasis, peak LDH, peak CRP, NEUT%, ferritin, ≥2/3 lung lobe consolidation, pleural effusion, bronchial mucous plugs, bronchial mucosal necrosis, PaO2/FiO2, andPaO2 can be used as predictors.

Clinical differences between Mycoplasma pneumoniae pneumonia and Streptococcus pneumoniae pneumonia: a case control study

Introduction

Mycoplasma pneumoniae pneumonia (MPP) and Streptococcus pneumoniae pneumonia (SPP) are frequent causes of respiratory tract infection, the aims of the study were to explore the differences in clinical features between children with MPP and those with SPP.

Methods

This retrospective study included admitted children who were diagnosed with MPP or SPP over 5 years from January 2015 to January 2020. Children with MPP were compared to children with SPP in terms of clinical features.

Results

506 patients with MPP were compared to 311 patients with SPP in terms of clinical differences. The MPP group with a median age of 60 [29-89] months and the SPP group with a median age of 24 [10-40] months. Patients with MPP were older and had a higher occurrence of receiving antibiotics before admission, fever, dry cough, polypnea and diarrhea than patients with SPP (all p < 0.01). Patients with SPP were more likely to have wheezing, cyanosis and irritability (all p < 0.01). Laboratory findings in our study showed that there were significant differences between MPP and SPP patients in mean leucocyte count, neutrophil % (N%), lymphocyte % (L%), ALT levels, AST levels, LDH levels and incidence of accelerated procalcitonin (PCT) (all p < 0.01). Lower age, no dry cough, no polypnea, lower LDH levels, and higher PCT might lead to the diagnosis of SPP. Our study showed that age had a higher accuracy in predicting MPP than LDH levels, with an age >48.5 months shown to be an independent predictive factor for the early evaluation and identification of MPP.

Discussion

In conclusion, patients with MPP and SPP usually present with fever, cough and some nonspecific symptoms. Our study showed that age, dry cough, polypnea, LDH levels, and PCT levels were independent predictive factors associated with MPP and SPP.

Model based on the automated AI-driven CT quantification is effective for the diagnosis of refractory Mycoplasma pneumoniae pneumonia

The prediction of refractory Mycoplasma pneumoniae pneumonia (RMPP) remains a clinically significant challenge. This study aimed to develop an early predictive model utilizing artificial intelligence (AI)-derived quantitative assessment of lung lesion extent on initial computed tomography (CT) scans and clinical indicators for RMPP in pediatric inpatients. A retrospective cohort study was conducted on patients with M. pneumoniae pneumonia (MP) admitted to the Children's Hospital of Nanjing Medical University, China from January 2019 to December 2020. An early prediction model was developed by stratifying the patients with Mycoplasma pneumoniae pneumonia (MPP) into two cohorts according to the presence or absence of refractory pneumonia. A retrospective cohort of 126 children diagnosed with Mycoplasma pneumoniae pneumonia (MPP) was utilized as a training set, with 85 cases classified as RMPP. Subsequently, a prospective cohort comprising 54 MPP cases, including 37 instances of RMPP, was assembled as a validation set to assess the performance of the predictive model for RMPP from January to December 2021. We defined a constant Φ which can combine the volume and CT value of pulmonary lesions and be further used to calculate the logarithm of Φ to the base of 2 (Log2Φ). A clinical-imaging prediction model was then constructed utilizing Log2Φ and clinical characteristics. Performance was evaluated by the area under the receiver operating characteristic curve (AUC). The clinical model demonstrated AUC values of 0.810 and 0.782, while the imaging model showed AUC values of 0.764 and 0.769 in the training and test sets, respectively. The clinical-imaging model, incorporating Log2Φ, temperature(T), aspartate aminotransferase (AST), preadmission fever duration (PFD), and preadmission macrolides therapy duration (PMTD), achieved the highest AUC values of 0.897 and 0.895 in the training and test sets, respectively. A prognostic model developed through automated quantification of lung disease on CT scans, in conjunction with clinical data in MPP may be utilized for the early identification of RMPP.

Clinical Features and Biomarkers for Early Prediction of Refractory Mycoplasma Pneumoniae Pneumonia in Children

Objective

The study aimed to analyze the clinical characteristics of children with RMPP and to explore the biomarkers for the early prediction of RMPP, thus providing references for the clinical diagnosis and treatment of RMPP in children.

Methods

Baseline clinical characteristics, clinical symptoms, physical examination, chest imaging, and laboratory indicators between children with RMPP and general refractory mycoplasma pneumoniae pneumonia (GMPP) were compared. Multiple logistic regression analysis was used to determine independent risk factors for RMPP. ROC curves were adopted to analyze the predictive values of biomarkers.

Results

The RMPP group had more severe clinical symptoms and manifestations on imaging (including pleural effusion, pulmonary consolidation, and pulmonary atelectasis), a higher incidence of extrapulmonary complications, and a longer duration of hospital stays. Results of multiple logistic regression analysis showed that serum D-dimer (OR = 8.169, P < 0.001), C-reactive protein (CRP) (OR = 1.146, P < 0.001), and lactate dehydrogenase (LDH) (OR = 1.025, P < 0.001) levels were independent risk factors for RMPP. The area under the receiver operating characteristic curve (AUROC) in RMPP prediction was 0.841, 0.870, and 0.893 for serum levels of D-dimer, CRP, and LDH, respectively (P < 0.001), with a cutoff value of 1.47 ng/ml, 39.34 mg/L, and 379 IU/L, respectively.

Conclusions

Serum D-dimer, CRP, and LDH levels were related to the severity of mycoplasma pneumoniae pneumonia in children and had potential as biomarkers for the early prediction of RMPP, suggesting great applicative values for the early diagnosis and timely intervention of children with RMPP in clinical practice.

Clinical features and risk factors of plastic bronchitis caused by Mycoplasma pneumoniae pneumonia in children

BACKGROUND

We analyzed the clinical characteristics of children with plastic bronchitis (PB) caused by Mycoplasma pneumoniae (MP) and explored its risk factors.

METHODS

We prospectively analyzed clinical data of children with MP pneumonia (MPP) treated with fiberoptic bronchoscopy (FB). Patients were classified into a PB and non-PB group. General information, clinical manifestations, laboratory tests, results of computed tomography scan, and FB findings were compared between groups. We conducted statistical analysis of risk factors for developing PB.

RESULTS

Of 1169 children who had MPP and were treated with FB, 133 and 1036 were in the PB and non-PB groups, respectively. There were no significant differences in sex, age, and incident season between groups (P > 0.05). The number of children in the PB group decreased during the COVID-19 pandemic. Compared with children in the non-PB group, those in the PB group had longer duration of hospitalization, increased levels of neutrophil (N), C-reactive protein (CRP), procalcitonin (PCT), D-dimer, lactate dehydrogenase (LDH), alanine transaminase (ALT) and aspartate transaminase (AST); lower levels of lymphocyte (L) and platelet (PLT); and higher incidence of lack of appetite, decreased breath sounds, single lobar infiltrate, pleural effusion, pericardial effusion, mucosal erosion and/or necrosis, and bronchial embolization. L levels and pleural effusion were identified as risk factors in multivariate logistic regression.

CONCLUSIONS

Children with PB caused by MPP had a strong and local inflammatory response. L levels and pleural effusion were independent risk factors of PB with MPP in children. Our findings will help clinicians identify potential PB in pediatric patients for early and effective intervention.

Recognition of refractory Mycoplasma pneumoniae pneumonia among Myocoplasma pneumoniae pneumonia in hospitalized children: development and validation of a predictive nomogram model

BACKGROUD

The current diagnostic criteria for refractory Mycoplasma pneumoniae pneumonia (RMPP) among Mycoplasma pneumoniae Pneumonia (MPP) are insufficient for early identification, and potentially delayed appropriate treatment. This study aimed to develop an effective individualized diagnostic prediction nomogram for pediatric RMPP.

METHODS

A total of 517 hospitalized children with MPP, including 131 with RMPP and 386 without RMPP (non-RMPP), treated at Lianyungang Maternal and Child Health Care Hospital from January 2018 to December 2021 were retrospectively enrolled as a development (modeling) cohort to construct an RMPP prediction nomogram. Additionally, 322 pediatric patients with MPP (64 with RMPP and 258 with non-RMPP, who were treated at the Affiliated Hospital of Xuzhou Medical University from June 2020 to May 2022 were retrospectively enrolled as a validation cohort to assess the prediction accuracy of model. Univariable and multivariable logistic regression analyses were used to identify RMPP risk factors among patients with MPP. Nomogram were generated based on these risk factors using the rms package of R, and the predictive performance was evaluated based on receiver operating characteristic (ROC) curves and using decision curve analysis (DCA).

RESULTS

Multivariate analysis revealed five significant independent predictors of RMPP among patients with MPP: age (hazard ratio [HR] 1.16, 95% confidence interval [CI] 1.08-1.33, P = 0.038), fever duration (HR 1.34, 95%CI 1.20-1.50, P < 0.001), lymphocyte count (HR 0.45, 95%CI 0.23-0.89, P = 0.021), serum D-dimer (D-d) level (HR 1.70, 95%CI 1.16-2.49, P = 0.006), and pulmonary imaging score (HR 5.16, 95%CI 2.38-11.21, P < 0.001). The area under the ROC curve was 90.7% for the development cohort and 96.36% for the validation cohort. The internal and external verification calibration curves were almost linear with slopes of 1, and the DCA curve revealed a net benefit with the final predictive nomogram.

CONCLUSION

This study proposes a predictive nomogram only based on five variables. The nomogram can be used for early identification of RMPP among pediatric patients with MPP, thereby facilitating more timely and effective intervention.

Pre-Pandemic Distribution of Bacterial Species in Nasopharyngeal Swab Specimens from Pediatric and Adult Patients Detected via RT-PCR Using the Allplex Respiratory Panel

Background: Recently, panel-based molecular diagnostics for the simultaneous detection of respiratory viruses and bacteria in nasopharyngeal swab (NPS) specimens have been highlighted. We identified the distribution of bacterial species in NPS specimens collected from pediatric and adult patients by employing RT-PCR (Allplex respiratory panel 4, RP4, Seegene) to estimate its applicability in a panel-based assay for detecting respiratory viruses. Methods: We used 271 and 173 NPS specimens from pediatric and adult patients, respectively. The results of the Allplex RP4 panel using NPS (NPS-RP4) from adult patients were compared with those of the Seeplex PneumoBacter ACE Detection assay (Seegene), which used sputum for testing (sputum-Seeplex). Results: A total of 147 specimens (54.2%) were positive for the NPS-RP4 panel in pediatric patients. There were 94, 77, 10, 3, 3, and 2 specimens that were positive for Haemophilus influenzae (HI), Streptococcus pneumoniae (SP), Mycoplasma pneumoniae (MP), Chlamydia pneumoniae (CP), Bordetella pertussis (BP), and B. parapertussis (BPP), respectively. Among 173 adult patients, 39 specimens (22.5%) were positive in the NPS-RP4. Thirty specimens were positive for HI, and 13 were positive for SP. One specimen tested positive for both MP and Legionella pneumophila (LP). CP, BP, and BPP results were all negative. However, 126 specimens (72.8%) had positive results with sputum-Seeplex (99 SP, 59 HI, three LP, and two MP), and the overall percentage of agreement between the two assays was 39.3% in the adult patients. Conclusions: Bacterial species in NPS from more than half of pediatric patients were detected. Performing the Allplex RP4 assay with NPS revealed additional respiratory bacteria that are not detected in current clinical practices, which do not include bacterial testing, demanding the use of sputum specimens. However, the use of NPS showed low agreement with standard assays using sputum in adult patients. Thus, more research is needed to develop a reliable RT-PCR method using NPS specimens in adult patients.

Mechanisms of Long-Term Persistence of Mycoplasmas in Children with Asthma

Improving the management of children with asthma associated with mycoplasma infection is important. Aim: To study the duration of the persistence of antigens, and DNA in a free state, in the structures of circulating immune complexes (CICs) and living cells of Mycoplasma pneumoniae (Mpn) and Mycoplasma hominis (Mh) in children with asthma. In total, 205 children with asthma from 1 to 14 years were observed. The reaction of aggregate-hemagglutination (AHAA), the direct immunofluorescence reaction (DIF), the reaction of the polymerase chain reaction (PCR), and the culture method were used. In addition, 47 children were re-examined 1.5 months after the treatment of mycoplasma infection with azithromycin. The number of samples positive for antigens and DNA in the free state and in the structures of CICs significantly decreased. Then, 50 blood serum samples containing Mh antigens, and 50 samples containing Mpn antigens were analyzed by culture method. Mh was isolated in 21 (65.5%) of 32 samples containing DNA. Mpn was isolated from antigen-positive samples in nine cases. The presented data indicate the long-term persistence of antigens, and DNA of mycoplasma cells in the free state, in the structure of CICs, as well as in the form of "microcolonies". A high level of CICs can be used to predict the course of the disease and the response to therapy.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Identification and comparison of Chlamydia psittaci, Legionella and Mycoplasma pneumonia infection

INTRODUCTION

Conventional etiological detection and pathogenic antibody methods make it challenging to identify the atypical pathogens among the community-acquired pneumonia (CAP). Metagenomic next-generation sequencing (mNGS) could rapidly detect all potentially infectious diseases and identifies novel or potential pathogens.

METHODS

Eighteen patients diagnosed with atypical CAP were enrolled in this retrospective study, including nine Chlamydia psittaci pneumonia (C. p), four Legionella pneumonia (L. p) and five Mycoplasma pneumonia (M. p). We simultaneously tested bronchoalveolar lavage fluid (BALF) samples for conventional microbiological methods and mNGS, and blood specimens were analysed. We also collected and compared baseline and clinical characteristics and treatment responses.

RESULTS

Patients with C. p and L. p had similar symptoms, including fever, cough, headache, dyspnoea, asthenia, shivering and headache, compared with M. p, whose symptoms were slight. C. p and L. p usually showed multiple lobar distributions with pleural effusion. Serologic testing indicated that L. p had higher levels of white blood cells (WBCs), neutrophils, C-reactive protein (CRP), procalcitonin (PCT), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and creatinine compared with M. p and L. p (p < 0.05). However, patients with C. p had lower levels of albumin (p < 0.05), and M. p had a minimum risk of cardiac volume loads (p < 0.05). CD4/CD8 ratio, lymphocytes, aspartate aminotransferase (AST), creatine kinase (CK), cell counting of BALF and coagulation had no difference (p < 0.05). Pathogenic IgM assay showed that 4/5 cases were positive for M. p and no positive detection for C. p and L. p infection. We timely adjusted the antibiotics according to the final mNGS results. Eventually, 16/18 patients recovered fully. Conditions of L. p patients were worse than those of C. p patients, and those of M. p patients were the least.

CONCLUSION

Early application of mNGS detection increased the atypical pathogenic identification, improved the prognosis and made up for the deficiency of conventional detection methods.

Clinical features and risk factors of plastic bronchitis caused by refractory Mycoplasma pneumoniae pneumonia in children: a practical nomogram prediction model

Early assessment of refractory Mycoplasma pneumoniae pneumonia (RMPP) with plastic bronchitis (PB) allows timely removal of casts using fiberoptic bronchoscopic manipulation, which relieves airway obstruction and limit sequelae development. This study aimed to analyze clinical data for risk factors and develop a nomogram for early predictive evaluation of RMPP with PB. The clinical data of 1-14 year-old patients with RMPP were retrospectively analyzed. Patients were classified into a PB or non-PB group. The general characteristics, clinical symptoms, laboratory test results, imaging findings, and microscopic changes of the two groups were compared. A statistical analysis of the risk factors for developing PB was performed, and a nomogram model of risk factors was constructed. Of 120 patients with RMPP included, 68 and 52 were in the non-PB and PB groups, respectively. Using multivariate logistic regression analysis, fever before bronchoscopy, extrapulmonary complications, pleural effusion, cough duration, and lactate dehydrogenase (LDH) levels were identified as risk factors. A nomogram was constructed based on the results of the multivariate analysis. The area under the receiver operating characteristic curve value of the nomogram was 0.944 (95% confidence interval: 0.779-0.962). The Hosmer-Lemeshow test displayed good calibration of the nomogram (p = 0.376, R2 = 0.723).

CONCLUSION

The nomogram model constructed in this study based on five risk factors (persistent fever before bronchoscopy, extrapulmonary complications, pleural effusion, cough duration, and LDH levels) prior to bronchoscopy can be used for the early identification of RMPP-induced PB.

WHAT IS KNOWN

• Refractory Mycoplasma pneumoniae pneumonia (RMPP) in children has been increasingly reported and recognized, which often leads to serious complications. • Plastic bronchitis (PB) is considered to be one of the causes of RMPP, and bronchoscopic treatment should be improved as soon as possible to remove plastic sputum thrombus in bronchus.

WHAT IS NEW

• This study determined the risk factors for RMPP-induced PB. • The nomogram model constructed in this study prior to bronchoscopy can be used for the early identification of RMPP-induced PB, which facilitate the early bronchoscopic removal of casts, thereby promoting recovery and reducing cases with poor RMPP prognosis.

Asthma with recurrent middle lobe syndrome in children: Clinical features and lung function patterns

BACKGROUND

Middle lobe syndrome (MLS) is a complication of childhood asthma. This study aimed to compare the clinical features and lung function between asthmatic children with recurrent MLS and transient right middle lobe (RML) and/or lingula atelectasis.

METHODS

This study retrospectively analyzed asthmatic children with RML and/or lingula atelectasis between 2010 and 2020 using data from the pediatric pulmonary department. According to the episodes of atelectasis, children were divided into recurrent (≥2 episodes) and non-recurrent (only 1 episode) MLS groups, to compare clinical features and lung function. Spirometry during acute asthma exacerbation and stable stages were recorded, and variations were calculated.

RESULTS

A total of 35 children with asthma and RML and/or lingula atelectasis were included, 15 of whom had recurrent MLS. The recurrent MLS group had a higher proportion of girls, infections, family allergy history, severe asthma, severe exacerbation, and higher levels of total IgE than the non-recurrent MLS group (P < 0.05). The recurrent MLS group had a significantly higher % predicted and z-scores for forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC), a greater proportion of high FEV₁ and higher variations in FEV₁ and FVC than that in the non-recurrent group (P < 0.05). After excluding children with mild to moderate asthma in the recurrent MLS group, the differences in clinical features disappeared, but the results regarding lung function remained similar, when compared to severe asthma patients without RML and/or lingula atelectasis.

CONCLUSIONS

Childhood asthma with recurrent MLS has more frequent severe asthma and exacerbation but high lung function and variations.

Progress in diagnosis and treatment of difficult-to-treat asthma in children

At present, medications containing inhaled corticosteroids (ICS-containing) are the keystones of asthma treatment. The majority of asthmatic children can significantly improve clinical outcomes with little worsening by standardized inhaled glucocorticoid treatment, but there is still a small proportion of children who are unable to achieve good symptom control even after the maximum standardized treatment, known as 'children with difficult-to-treat asthma (DA)'. The high heterogeneity of DA makes therapy challenging and expensive, which poses a serious risk to children's health and makes it extremely difficult for clinical physicians to accurately identify and treat children with DA. This article reviews the definition, evaluation, and treatment of this asthma in order to provide a reference for optimal clinical decision-making.

Clinical role of M. pneumoniae typing antibody detected by chemiluminescent immunoassay in the diagnosis of Mycoplasma pneumoniae pneumonia in children

OBJECTIVE

The levels of serum M. pneumoniae typing antibodies in children with community-acquired pneumonia (CAP) were detected by chemiluminescent immunoassay (CLIA) to explore the clinical role of M. pneumoniae typing antibody (MP-IgM, MP-IgG) in M. pneumoniae pneumonia.

METHODS

A total of 387 Child patients with CAP diagnosed at the Pediatric outpatient department of Zengcheng Branch, Nanfang Hospital, Southern Medical University, were enrolled between January 2020 to December 2021 and divided into M. pneumoniae pneumonia (MPP) group (n = 210) and non-M. pneumoniae pneumonia (NMPP) group (n = 177). Firstly, Clinical data, full blood count (WBC, NEU%, LYM%, MONO%, EOS%, BASO%, RBC, HGB, PLT) and biochemical tests (AST, LDH, ɑ-HBDH, CK, CKMB, CRP, PCT, IL-6) as well as laboratory diagnostic tests (MP-IgM, MP-IgG) were compared between the two groups. Secondly, we assessed the correlation between the average level of M. pneumoniae typing antibody detected by CLIA and the titer of anti-M. pneumoniae antibody (MP-Ab) tested by passive agglutination (PA) method. Thirdly, receiver operating characteristic (ROC) curve for the MP-IgM and MP-IgG was examined to evaluate the value of diagnosing M. pneumoniae pneumonia. Finally, we follow-up 120 cases of MPP group and analysis medication results.

RESULTS

(1) Mean age, runny nose, expectoration, LYM%, NEU%, HGB, AST, MP-IgM and MP-IgG were statistically significant in the MPP group and NMPP group (all P < 0.05). (2) Correlation analysis showed that MP-IgM average level was linearly associated with MP-Ab titer (R² = 0.84) and MP-IgG average level was exponentially correlated with MP-Ab titer under 1:640 (R² = 0.96). (3) The ROC curve of MP-IgM and MP-IgG were significantly different (both P < 0.001). A serum MP-IgM level above 1 S/CO and MP-IgG level above 14.15 AU/mL were significant predictors for M. pneumoniae pneumonia: area under the curve (AUC) of 0.810, 0.815; standard error (SE) of 0.021, 0.022; 95 % confidence interval (CI) of 0.768-0.852, 0.773-0.858; the diagnostic sensitivity of 74.3 %, 62.1 %; and specificity of 72.9 %, 87.0 %; respectively. (4) Of the 120 children with M. pneumoniae pneumonia followed up, 79 (65.8 %) cases took azithromycin and 68 (86.1 %) cases were recovered.

CONCLUSIONS

A series of our studies shown that, CLIA, speedy and automated clinical examination method, has higher specificity and sensitivity for the quantitative detection of MP-IgM and MP-IgG, playing an important role of early diagnosis as well as prompt intervention to reduces macrolide-resistant strains and sequelae of children with M. pneumoniae pneumonia.

Global Trends in the Proportion of Macrolide-Resistant Mycoplasma pneumoniae Infections: A Systematic Review and Meta-analysis

IMPORTANCE

The proportion of macrolide-resistant Mycoplasma pneumoniae (MRMP) infections has changed, and it differs according to geographical region.

OBJECTIVE

To analyze the global patterns, including the temporal trends, regional variations, and variant types, in the proportion of MRMP infections in this systematic review and meta-anaysis.

DATA SOURCES

PubMed, Cochrane Library, and Embase databases were searched for observational studies from inception to September 10, 2021.

STUDY SELECTION

Observational studies reporting the proportion of MRMP infections were screened independently by 2 authors. The presence of MRMP infection was defined as any case of M pneumoniae infection positive for any variants associated with macrolide resistance identified using respiratory samples.

DATA EXTRACTION AND SYNTHESIS

Data were extracted independently and in duplicate by 2 reviewers. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was used. Random-effects meta-analyses were used to estimate the proportion of MRMP infections.

MAIN OUTCOMES AND MEASURES

The global patterns in the proportion of MRMP infections were estimated, and the temporal trends and variant types of MRMP infection with regional differences were investigated.

RESULTS

This study included 153 studies from 150 articles (27 408 samples in 26 countries) in the meta-analysis. The global patterns in the proportion of MRMP infections showed an increasing trend with regional differences. The proportion of MRMP infections was highest in the Western Pacific regions (53.4%; 95% CI, 47.4%-60.3%), followed by the South East Asian region (9.8%; 95% CI, 0.8%-100%), the region of the Americas (8.4%; 95% CI, 6.1%-11.6%), and the European region (5.1%; 95% CI, 3.3%-8.0%). The most commonly identified variant of MRMP infection was A2063G (96.8%; 95% CI, 95.8%-97.7%), followed by A2064G (4.8%; 95% CI, 3.5%-6.7%). The proportion of MRMP infections was the highest in studies including only children (37.0%; 95% CI, 29.8%-46.1%), followed by those including only adults (15.9%; 95% CI, 6.4%-39.7%) and those including both children and adults (16.7%; 95% CI, 10.1%-27.6%).

CONCLUSIONS AND RELEVANCE

This study provides global trends in the proportion of MRMP infections and suggests that strategies to prevent the spread of MRMP infection and to treat MRMP infections are needed to decrease disease burden.

Refractory Mycoplasma pneumoniae Pneumonia in Children: Early Recognition and Management

Refractory Mycoplasma pneumoniae pneumonia (RMPP) is a severe state of M. pneumoniae infection that has attracted increasing universal attention in recent years. The pathogenesis of RMPP remains unknown, but the excessive host immune responses as well as macrolide resistance of M. pneumoniae might play important roles in the development of RMPP. To improve the prognosis of RMPP, it is mandatory to recognize RMPP in the early stages, and the detection of macrolide-resistant MP, clinical unresponsiveness to macrolides and elevated proinflammatory cytokines might be clues. Timely and effective anti-mycoplasmal therapy and immunomodulating therapy are the main strategies for RMPP.

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.

Effects of bronchoalveolar lavage on Mycoplasma Pneumoniae pneumonia: A propensity score matched-cohort study

BACKGROUND

The purpose of this study was to evaluate the efficacy and safety of BAL in treating MPP.

METHODS

From January 2013 to January 2019, 1,689 pediatric patients with MPP were analyzed retrospectively. Patients were subdivided into BAL group and non-BAL group according to whether they received BAL treatment within seven days after admission. The propensity score matching method matched patients' baseline characteristics (1:1). The primary outcomes were hospital stays and the cure rate. Secondary outcomes included mortality, co-infection, repeat hospitalization within 30 days, and total cost of treatment.

RESULTS

After matching, 524 patients (BAL: 262; control: 262) were recorded. The BAL group had significantly shorter hospital stays (OR: 0.5, 95% CI: 0.4-0.7). Meanwhile, BAL did not significantly modify the cost, co-infection rate, and mortality. In subgroup analyses, the group with BAL intervention within three days had a significantly shorter hospital stay (OR: 0.4, 95% CI: 0.3-0.5) compared with the group with BAL intervention three days after admission.

CONCLUSIONS

Early BAL intervention is a better treatment than conventional drug therapy alone, and no significant complications were seen in this study. BAL intervention has an excellent clinical benefit. The earlier the intervention, the better the effect.