Effects of Methylprednisolone Pulse Therapy on Refractory Mycoplasma pneumoniae Pneumonia in Children

Challenges in the treatment of pediatric Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is an important cause of community-acquired pneumonia in children and young adolescents. Despite macrolide antibiotics effectiveness as a first-line therapy, persistence of fever and/or clinical deterioration sometimes may complicate treatment and may even lead to severe systemic disease. To date, there is no consensus on alternative treatment options, optimal dosage, and duration for treating severe, progressive, and systemic MP pneumonia after macrolide treatment failure. Macrolide-resistant MP pneumonia and refractory MP pneumonia are the two major complex conditions that are clinically encountered. Currently, the vast majority of MP isolates are resistant to macrolides in East Asia, especially China, whereas in Europe and North America, whereas in Europe and North America prevalence is substantially lower than in Asia, varying across countries. The severity of pneumonia and extrapulmonary presentations may reflect the intensity of the host's immune reaction or the dissemination of bacterial infection. Children infected with macrolide-resistant MP strains who receive macrolide treatment experience persistent fever with extended antibiotic therapy and minimal decrease in MP-DNA load. Alternative second-line agents such as tetracyclines (doxycycline or minocycline) and fluoroquinolones (ciprofloxacin or levofloxacin) may lead to clinical improvement after macrolide treatment failure in children. Refractory MP pneumonia reflects a deterioration of clinical and radiological findings due to excessive immune response against the infection. Immunomodulators such as corticosteroids and intravenous immunoglobulin (IVIG) have shown promising results in treatment of refractory MP pneumonia, particularly when combined with appropriate antimicrobials. Corticosteroid-resistant hyperinflammatory MP pneumonia represents a persistent or recrudescent fever despite corticosteroid therapy with intravenous methylprednisolone at standard dosage.

CONCLUSION

 This report summarizes the clinical significance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drugs, with a stepwise approach to the management of MP pneumonia recommended from the viewpoint of clinical practice.

WHAT IS KNOWN

• Although MP pneumonia is usually a benign self-limited infection with response macrolides as first line therapy, severe life-threatening cases may develop if additional treatment strategies are not effectively implemented. • Macrolide-resistant and refractory MP pneumonia are two conditions that may complicate the clinical course of MP pneumonia, increasing the risk for exacerbation and even death.

WHAT IS NEW

• This report summarizes the clinical relevance of macrolide-resistant and refractory MP pneumonia and discusses the efficacy and safety of alternative drug therapies. • A practical stepwise approach to the management of MP pneumonia is developed based on a comprehensive analysis of existing evidence and expert opinion.

Pulmonary Thrombotic Complication of Mycoplasma pneumoniae Pneumonia in Chinese Children: Clinical Feature and Risk Factor Analysis

BACKGROUND

Thrombotic disease is a rare but severe complication of Mycoplasma pneumoniae pneumonia in children, with pulmonary thrombosis (PT) being the most frequent type. This study aims to describe the clinical features of pediatric severe Mycoplasma pneumoniae pneumonia (SMPP) patients with PT, and to identify risk factors predictive of PT development in this population.

METHODS

We retrospectively enrolled 60 children with SMPP complicated by PT who were admitted to Children's Hospital Affiliated to Zhengzhou University from January 2019 to October 2023. We reviewed their demographic data, laboratory tests and imaging examinations to describe their clinical features. We used multivariate logistic regression analysis to identify significant risk factors for PT in SMPP.

RESULTS

The PT group exhibited higher incidences of chest pain, hemoptysis, inflammation and elevated D-dimer levels, as well as more severe pulmonary damage and transaminitis complication, compared to the non-PT group. The left pulmonary artery was the predominant location of PT in SMPP children. A multivariate analysis revealed that C-reactive protein (CRP) and D-dimer were significant predictors of PT in SMPP patients, with odds ratios of 1.10 and 3.37, respectively. The optimal cutoff values of CRP and D-dimer for predicting PT in SMPP were 76.73 mg/L and 3.98 µg/mL, respectively.

CONCLUSIONS

In SMPP, CRP >76.73 mg/L and D-dimer >3.98 µg/mL are independent predictors of PT. These findings suggest that SMPP-induced excessive inflammation may contribute to PT pathogenesis. Early and intensive anticoagulant, anti-inflammatory and antimycoplasma therapy may improve the disease course and prognosis.

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.

Global research trends of Mycoplasma pneumoniae pneumonia in children: a bibliometric analysis

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP), attributable to Mycoplasma pneumoniae (MP), represents a predominant form of community-acquired pneumonia in pediatric populations, thereby posing a significant threat to pediatric health. Given the burgeoning volume of research literature associated with pediatric MPP in recent years, it becomes imperative to undertake a bibliometric analysis aimed at delineating the current research landscape and emerging trends, thereby furnishing a framework for subsequent investigations.

METHODS

A comprehensive literature search targeting pediatric MPP was conducted in the Web of Science Core Collection. After the removal of duplicate entries through Endnote software, the remaining articles were subject to scientometric analysis via Citespace software, VOSviewer software and R language, focusing on variables such as publication volume, contributing nations, institutions and authors, references and keywords.

RESULTS

A total of 1,729 articles pertinent to pediatric MPP were included in the analysis. China and the United States emerged as the nations with the highest publication output. Italian scholar Susanna Esposito and Japanese scholar Kazunobu Ouchi were the most influential authors in the domain of pediatric MPP. Highly-cited articles primarily focused on the epidemiological investigation of pediatric MPP, the clinical characteristics and treatment of macrolide-resistant MPP, and biomarkers for refractory Mycoplasma pneumoniae pneumonia (RMPP). From the corpus of 1,729 articles, 636 keywords were extracted and categorized into ten clusters: Cluster #0 centered on molecular-level typing of macrolide-resistant strains; Cluster #1 focused on lower respiratory tract co-infections; Clusters #2 and #6 emphasized other respiratory ailments caused by MP; Cluster #3 involved biomarkers and treatment of RMPP; Clusters #4 and #9 pertained to extrapulmonary complications of MPP, Clusters #5 and #7 addressed etiological diagnosis of MPP, and Cluster #8 explored pathogenic mechanisms.

CONCLUSIONS

The past few years have witnessed extensive attention directed towards pediatric MPP. Research in pediatric MPP principally revolves around diagnostic techniques for MP, macrolide resistance, complications of MPP, treatment and diagnosis of RMPP, and elucidation of pathogenic mechanisms. The present study provides pediatric clinicians and researchers with the research status and focal points in this field, thereby guiding the orientation of future research endeavors.

Clinical features and “early” corticosteroid treatment outcome of pediatric mycoplasma pneumoniae pneumonia

Background

Many children with mycoplasma pneumoniae (MP) pneumonia (MPP) developed sequelae such as bronchiolitis/bronchitis obliterans (BO). Early corticosteroid therapy might prevent disease progression. This study aimed to use “early” corticosteroid and observe the treatment outcome in patients with MPP.

Methods

Patients who had pulmonary infiltrations on chest imaging within 5 days of the disease course and were suspected of having MP infection on admission were enrolled. Among them, patients whose disease course was within 10 days on admission were ultimately enrolled. We analyzed their data including the clinical features, the starting time and dose of corticosteroid therapy, and the treatment outcome. According to chest imaging, we divided patients into two groups (Group A: bronchiolitis-associated lesions or ground-glass opacities; Group B: pulmonary segmental/lobar consolidation).

Results

A total of 210 patients with confirmed MPP were ultimately enrolled. There were 59 patients in Group A and 151 patients in Group B. Patients in Group A were more prone to have allergy histories, hypoxemia, wheezing sound, and wet rales on auscultation than those in Group B. Corticosteroid treatment was initiated between 5 and 10 days of disease onset in all patients and 6–7 days in most patients. Methylprednisolone was prescribed in all patients within 10 days of disease onset, and the highest prescribed dose was at least 2 mg/kg/day. In Group A, methylprednisolone &gt;2 mg/kg/day was prescribed in 22 patients, and among them, 8 patients with diffuse bronchiolitis-associated lesions received high-dose methylprednisolone therapy. After 3 months, lung CT revealed slightly segmental ground-glass opacity in three patients. In Group B, methylprednisolone &gt;2 mg/kg/day was prescribed in 76 patients, and among them, 20 patients with pulmonary lobar consolidation received high-dose methylprednisolone therapy. After 3 months, chest imaging revealed incomplete absorption of pulmonary lesions in seven patients. Among them, five patients with consolidation in more than one pulmonary lobe ultimately had slight BO.

Conclusion

In hospitalized patients with MPP, particularly severe MPP, the ideal starting time of corticosteroid treatment might be 5–10 days, preferably 6–7 days, after disease onset. The initial dosage of corticosteroid therapy should be decided according to the severity of the disease. MPP patients with diffuse bronchiolitis-associated lesions/whole lobar consolidation on imaging might require high-dose corticosteroid therapy.

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.

Effects of propofol and sevoflurane on T-cell immune function and Th cell differentiation in children with SMPP undergoing fibreoptic bronchoscopy

OBJECTIVES

The potentially different effects of commonly used anaesthetic agents propofol and sevoflurane on T-cell immune function and Th cell differentiation were investigated in patients with severe mycoplasmal pneumonia (SMPP) undergoing fibreoptic bronchoscopy.

METHODS

Sixty children (2-12 years of age) with SMPP were randomized into the sevoflurane group and the propofol group. Patients in the sevoflurane group were anaesthetised with inhalational sevoflurane and intravenous remifentanil. Patients in the propofol group were anaesthetised with intravenous propofol and remifentanil. Patients in both groups underwent fibreoptic bronchoscopy and lavage therapy. We compared the clinical outcomes, cellular immunity function, and Th cell differentiation into Th1 and Th2 levels in both groups.

RESULTS

There was no significant difference in clinical outcomes and hospital stay between the two groups (7.94 vs 7.36, p > .05). However, the CD3⁺ T cells, CD4⁺ T cells, and CD4⁺/CD8⁺ in the propofol group were significantly higher than those in the sevoflurane group (T1 51.96 vs 48.33, T2 58.08 vs 55.31, p < .05). The ratio of Th₁/Th₂ in the two groups was significantly increased postoperatively in both groups (Sevoflurane 8.53 vs 7.23, Propofol 9.35 vs 7.18), and the propofol group was significantly higher than the sevoflurane group (9.35 vs 8.53, p < .05).

CONCLUSIONS

Propofol might have a less inhibitory effect on T lymphocytes in children with SMPP than sevoflurane. And propofol may have less impact on the differentiation of Th cells into Th₁ cells and better preserving the Th₁/Th₂ ratio than sevoflurane. KEY MESSAGESThe pathogenesis of SMPP is still unclear, likely through alveolar infiltration with neutrophils and lymphocytes, lymphocyte/plasma cell infiltrates in the peri-bronchovascular area, and immune dysfunction.Recent experimental and clinical studies showed that sevoflurane might have immunosuppressive effects, and multiple studies confirmed that the immune function of children with SMPP had been reduced.This study found that propofol administered in children with SMPP had a less inhibitory effect on T lymphocytes than inhalational sevoflurane, had little inhibitory effect on the differentiation of Th cells into Th1 cells, and better preserve Th1/Th2 ratio and maintain the balanced immune function.

Development and validation of a nomogram to predict plastic bronchitis in children with refractory Mycoplasma pneumoniae pneumonia

Background

Early identification of plastic bronchitis (PB) is of great importance and may aid in delivering appropriate treatment. This study aimed to develop and validate a nomogram for predicting PB in patients with refractory Mycoplasma pneumoniae pneumonia (RMPP).

Methods

A total of 547 consecutive children with RMPP who underwent fiberoptic bronchoscopy (FOB) intervention from January 2016 to June 2021 were enrolled in this study. Subsequently, 374 RMPP children (PB: 137, without PB: 237) from January 2016 to December 2019 were assigned to the development dataset to construct the nomogram to predict PB and 173 RMPP children from January 2020 to June 2021 were assigned to the validation dataset. The clinical, laboratory and radiological findings were screened using Least Absolute Shrinkage and Selection Operator (LASSO) regression and logistic regression was applied to construct a nomogram. The performance of the nomogram was evaluated by discrimination, calibration and clinical utility. Comparsion of ROC analysis and decision curve analysis (DCA) between nomogram and other models was performed to evaluate the discrimination ability and clinical utility.

Results

The development dataset included 374 patients with a mean age of 6.6 years and 185(49.5%) were men. The validation dataset included 173 patients and the mean age of the dataset was 6.7 years and 86 (49.7%) were men. From 26 potential predictors, LASSO regression identified 6 variables as significant predictive factors to construct the nomogram for predicting PB, including peak body temperature, neutrophil ratio (N%), platelet counts (PLT), interleukin-6 (IL-6), actic dehydrogenase (LDH) and pulmonary atelectasis. The nomogram showed good discrimination, calibration and clinical value. The mean AUC of the nomogram was 0.813 (95% CI 0.769–0.856) in the development dataset and 0.895 (95% CI 0.847–0.943) in the validation dataset. Through calibration plot and Hosmer–Lemeshow test, the predicted probability had a good consistency with actual probability both in the development dataset (P = 0.217) and validation dataset (P = 0.183), and DCA showed good clinical utility. ROC analysis indicated that the nomogram showed better discrimination ability compared with model of peak body temperature + pulmonary atelactsis and another model of N% + PLT + IL-6 + LDH, both in development dataset (AUC 0.813 vs 0.757 vs 0.754) and validation dataset (AUC 0.895 vs 0.789 vs 0.842).

Conclusions

In this study, a nomogram for predicting PB among RMPP patients was developed and validated. It performs well on discrimination ability, calibration ability and clinical value and may have the potential for the early identification of PB that will help physicians take timely intervention and appropriate management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02047-2.

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.

Clinical significance of Mycoplasma pneumoniae specific IgM titer in children hospitalized with Mycoplasma pneumoniae pneumonia

BACKGROUND

The present study aimed to identify the clinical significance of Mycoplasma pneumoniae (MP)-specific immunoglobulin M (IgM) titer, in addition to a diagnosis of MP infection, in children with MP pneumonia.

METHODS

This study was performed in 155 children hospitalized with MP pneumonia. The clinical features and laboratory and radiographic findings on admission in children with positive or negative MP-specific IgM titers were retrospectively reviewed from the electronic medical records.

RESULTS

The mean age of the included children was 6.0 years, and 118 (76.1%) of the children were positive for MP-specific IgM. A longer duration between symptom onset and admission (adjusted odds ratio [aOR] 1.47, 95% confidence interval [CI] 1.24-1.75), longer duration of symptoms during the illness (aOR 1.15, 95% CI 1.02-1.30), and development of extra-pulmonary manifestations (aOR 9.16, 95% CI 1.96-42.81) were significantly associated with a positive MP-specific IgM titer. Serum lactate dehydrogenase levels (aOR 1.00, 95% CI 1.00-1.01) and pneumonic infiltration involving > 50% of the total lung volume on chest radiography (aOR 4.68, 95% CI 1.12-19.55) were associated with positive MP-specific IgM in children with MP pneumonia. A poor response to stepwise treatment for MP pneumonia was more common in children with a positive MP-specific IgM titer than those with a negative MP-specific IgM titer on admission.

CONCLUSIONS

A positive MP-specific IgM titer at diagnosis of MP pneumonia may partially suggest an exaggerated immune response with a higher disease burden compared to children with MP pneumonia with a negative MP-specific IgM titer.

Recent Trends in the Epidemiology, Diagnosis, and Treatment of Macrolide-Resistant Mycoplasma pneumoniae

Among Mycoplasma pneumoniae (MP) is one of the major pathogens causing lower respiratory tract infection. Macrolide-resistant Mycoplasma pneumoniae (MRMP) isolates have been increasing and has become a global concern, especially in East Asian countries. This affects the treatment of MP infection; that is, some patients with MRMP infections fever cannot be controlled despite macrolide therapy. Therefore, alternative therapies, including secondary antimicrobials, including tetracyclines, fluoroquinolones, or systemic corticosteroids, were introduced. However, there are insufficient data on these alternative therapies. Thus, this article provides reviews of the recent trends in the epidemiology, diagnosis, and treatment of MRMP.

Severe pediatric Mycoplasma pneumonia as the cause of diffuse alveolar hemorrhage requiring veno-venous extracorporeal membrane oxygenation: A case report

BACKGROUND

Diffuse alveolar hemorrhage (DAH) is an acute life-threatening disease often associated with immunocompromised patients and systemic disorders, such as infections, vasculitis, and toxins. Mycoplasma pneumoniae is one of the most common causes of community-acquired pneumonia in children, which rarely causes respiratory failure and fulminant disease; However, a rapid progression may occur in some patients. Mycoplasma pneumonia-associated DAH is rare.

CASE PRESENTATION

We report a case of severe pediatric mycoplasma pneumonia in an immuno-competent child. This patient's condition progressed rapidly, with severe lung lesions associated with pleural effusion, coagulopathy, diffuse alveolar haemorrhage and severe respiratory distress requiring ventilator and intravenous extracorporeal membrane oxygenation (VV-ECMO) support. She was discharged upon successful treatment.

CONCLUSION

Diffuse alveolar hemorrhage associated with Mycoplasma pneumoniae in children is very rare, and clinicians should be aware of the potential rapid onset of the disease. Early detection and diagnosis are very important. The main treatment measures include anti-infection and supportive measures such as mechanical ventilation, but as in our case, success with both prone positioning for more than 10 h per day and VV-ECMO was life-saving.

Risk factors for delayed radiographic resolution in children with refractory Mycoplasma pneumoniae pneumonia

OBJECTIVE

To determine the risk factors for delayed radiographic resolution in children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and explore the most suitable time for interventional bronchoscopy.

METHODS

This retrospective study involved 142 children with RMPP who were admitted to our hospital from 1 January 2015 to 31 December 2017. They were divided into a common resolution group and a delayed resolution group based on their chest radiograph series.

RESULTS

Among the 142 patients, 67 showed common resolution on chest radiographs and 75 showed delayed resolution. Independent risk factors for delayed resolution were a clinical course of ≥11.5 days before the performance of interventional bronchoscopy, mucus plug formation, corticosteroid resistance, and atelectasis. When bronchoscopy was performed before the disease had been present for <11.5 days, the length of hospitalization, total fever duration, and duration of time until disappearance of coughing were shorter than those in children who underwent bronchoscopy after the disease had been present for ≥11.5 days.

CONCLUSIONS

Corticosteroid resistance, the time to interventional bronchoscopy, atelectasis, and mucus plug formation were associated with delayed resolution on chest radiographs. Performance of interventional bronchoscopy before the clinical course has reached 11.5 days may help alleviate clinical symptoms and improve radiographic resolution.

Development of a scale for early prediction of refractory Mycoplasma pneumoniae pneumonia in hospitalized children

Now there is no clinical scale for early prediction of refractory Mycoplasma pneumoniae pneumonia (RMPP). The aim of this study is to identify indicators and develop an early predictive scale for RMPP in hospitalized children. First we conducted a retrospective cohort study of children with M. pneumoniae pneumonia admitted to Children's Hospital of Nanjing Medical University, China in 2016. Children were divided into two groups, according to whether their pneumonia were refractory and the results were used to develop an early predictive scale. Second we conducted a prospective study to validate the predictive scale for RMPP in children in 2018. 618 children were included in the retrospective study, of which 73 with RMPP. Six prognostic indicators were identified and included in the prognostic assessment scale. The sensitivity of the prognostic assessment scale was 74.0% (54/73), and the specificity was 88.3% (481/545) in the retrospective study. 944 children were included in the prospective cohort, including 92 with RMPP, the sensitivity of the prognostic assessment scale was 78.3% (72/92) and the specificity was 86.2% (734/852). The prognostic assessment scale for RMPP has high diagnostic accuracy and is suitable for use in standard clinical practice.

The risk factors of children acquiring refractory mycoplasma pneumoniae pneumonia: A meta-analysis

OBJECTIVES

Refractory mycoplasma pneumoniae pneumonia (RMPP) in children has been increasing worldwide. In this study, we conducted a meta-analysis to generate large-scale evidence on the risk factors of RMPP to provide suggestions on prevention and controlling for children.

METHODS

Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, and Wanfang (Chinese) were searched to identify relevant articles. All analyses were performed using Stata 14.0.

RESULTS

We conducted a meta-analysis of 15 separate studies. Fever for more than 10 days (odds ratio [OR] 3.965, 95% confidence interval [CI] 2.109-7.456), pleural effusion (OR 6.922, 95% CI 2.058-23.282), extra-pulmonary complications (OR 17.762, 95% CI 11.146-28.305), pulmonary X-ray consolidation ≥2/3 (OR 8.245, 95% CI 1.990-34.153), CRP >40 mg/L (OR 4.975, 95% CI 2.116-11.697) were significantly related to the risk of RMPP. We did not find an association between male sex (OR 0.808, 95% CI 0.548-1.189), LDH >410IU/L (OR 1.033, 95% CI 0.979-1.091) and the risk of RMPP.

CONCLUSIONS

Fever for more than 10 days, pleural effusion, extra-pulmonary complications, pulmonary X-ray consolidation≥ 2/3 and CRP >40 mg/L are risk factors for early evaluation of RMPP.

Predictive Factors of the Responses to Treatment of Mycoplasma pneumoniae Pneumonia

The prevalence of refractory Mycoplasma pneumoniae (MP) pneumonia is increasing. The present study aimed to identify the predictive factors of responses to treatment of MP pneumonia in children. A total of 149 children were diagnosed with MP pneumonia, of whom 56 were included in the good response group, 75 children in the slow response group, and 18 children in no response or progression group. Data on the clinical, laboratory, and radiologic features were retrospectively obtained through medical chart reviews. The severity of pneumonia, based on the extent of pneumonic lesions on chest x-ray (adjusted odds ratio (aOR), 10.573; 95% confidence intervals (CIs), 2.303-48.543), and lactate dehydrogenase (LDH) levels (aOR, 1.002; 95% CIs, 1.000-1.004) at the time of admission were associated with slow response to treatment of MP pneumonia. Pleural effusion (aOR, 5.127; 95% CIs, 1.404-18.727), respiratory virus co-infection (aOR, 4.354; 95% CIs, 1.374-13.800), and higher LDH levels (aOR, 1.005; 95% CIs, 1.002-1.007) as well as MP-specific IgM titer (aOR, 1.309; 95% CIs, 1.095-1.564) were associated with no response or progression of MP pneumonia. The area under the curve for the prediction of no or poor response in MP pneumonia using pleural effusion, respiratory virus co-infection, LDH levels, and MP-specific IgM titer at the time of admission was 0.8547. This study identified the predictive factors of responses to treatment of MP pneumonia in children, which would be helpful in establishing a therapeutic plan and predicting the clinical course of MP pneumonia in children.

Early Confirmation of Mycoplasma pneumoniae Infection by Two Short-Term Serologic IgM Examination

The aim of the present study is to re-evaluate the clinical application of two-times serologic immunoglobulin M (IgM) tests using microparticle agglutination assay (MAA), an enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) assay in diagnosing Mycoplasma pneumoniae (MP) infection. A retrospective analysis of 62 children with MP pneumonia during a recent epidemic (2019–2020) was conducted. The MAA and ELISA immunoglobulin M (IgM) and IgG measurements were conducted twice at admission and around discharge, and MP PCR once at presentation. Diagnostic rates in each test were calculated at presentation and at discharge. The seroconverters were 39% (24/62) of patients tested by MAA and 29% (18/62) by ELISA. At presentation, the diagnostic positive rates of MAA, ELISA, and PCR tests were 61%, 71%, and 52%, respectively. After the second examination, the rates were 100% in both serologic tests. There were positive correlations between the titers of MAA and the IgM values of ELISA. The single serologic IgM or PCR tests had limitations to select patients infected with MP in the early stage. The short-term, paired IgM serologic tests during hospitalization can reduce patient-selection bias in MP infection studies.

Mycoplasma pneumoniae: a pathogen with unsolved therapeutic problems

INTRODUCTION

Despite the amount of new information, the most effective approach for the diagnosis and treatment of Mycoplasma pneumoniae infections is not established. In this narrative review the pharmacological options for macrolide-resistant (ML) M. pneumoniae infections in children are discussed.

AREAS COVERED

Despite significant improvement in the diagnosis and in the definition of diseases potentially associated with this pathogen, not all the problems related to M. pneumoniae infection are solved. True epidemiology of M. pneumoniae diseases and the real role of this pathogen in extra-respiratory manifestations is still unestablished. This reflects on therapy. It is not known whether antibiotics are really needed in all the cases, independently of severity and localization. The choice of antibiotic therapy is debated as it is not known whether ML resistance has clinical relevance. Moreover, not precisely defined is the clinical importance of corticosteroids for improvement of severe cases, including those associated with ML-resistant strains.

EXPERT OPINION

Improvement in M. pneumoniae identification is mandatory to reduce antibiotics overuse , especially in the presence of ML-resistant strains. Priority for future studies includes the evaluation of the true benefit of therapeutic approaches including corticosteroids in patients with severe CAP and in those with extra-respiratory M. pneumoniae diseases.

The effect of vibrating positive expiratory pressure therapy on refractory Mycoplasma pneumoniae pneumonia prognosis in children

BACKGROUND

It is well documented that vibration techniques and positive expiratory pressure (PEP) can improve airway clearance, however, few clinical trials have studied the efficacy of vibrating PEP therapy on refractory Mycoplasma pneumoniae (M. pneumoniae) pneumonia (RMPP) in children. This study aimed to explore using vibrating PEP therapy in children with RMPP.

METHODS

Sixty participants in the remission stage of RMPP were recruited into this randomized study and divided into two groups. The Acapella group (n=30) used the Acapella^® Choice twice daily for 2 months to clear their airways. The control group (n=30) used traditional chest percussion or postural drainage to mediate sputum expectoration. The groups administered their respective treatments at home and were followed up weekly. Participants kept a record of their treatment and condition in a daily log. The primary outcome of this study was the resolution of chest images, and the secondary outcome was the sputum period.

RESULTS

There was no significant difference in sex or age distribution between the two groups. There were no significant differences at baseline between the groups in the location of their lesions (P=0.11). After 2 months of treatment, there was a better resolution of chest images in the Acapella group (P=0.00) compared with the control group. Additionally, the mean sputum period was significantly shorter for the Acapella group than for the control group (Acapella: 7.97±1.54 days; control: 11.90±1.64 days; P=0.00).

CONCLUSIONS

Vibrating PEP therapy is an effective therapy for children with RMPP, both in airway clearance and the resolution of lung abnormalities.

Case Report: Clinical Analysis of Fulminant Mycoplasma pneumoniae Pneumonia in Children

Fulminant Mycoplasma pneumoniae pneumonia (FMPP) accounts for 0.5-2% of all MPP cases, which is considered as MPP combined with severe complications such as hypoxemia, acute respiratory distress syndrome, or acute respiratory failure. It primarily affects young adults with no underlying disease. Although some studies have proved the severity of FMPP, the details about clinical diagnosis and treatment of FMPP in children have been rarely reported. In this case study, we described three cases who suffered from FMPP. These children not only developed acute lung injury and multiple organ involvement within 7 days of treatment, but were also found plastic bronchitis by bronchoscopy. Finally, all the patients were treated successfully with azithromycin, glucocorticoid, and bronchoscopy lavage. We conclude that this case study would contribute to raise awareness with respect to FMPP, which may occur at a younger age with faster disease progression and common extrapulmonary manifestations. It also reinforces the importance of early identification and prompt intervention to save life of children and reduces sequelae. Further studies are needed about mechanism of FMPP.

Rational stepwise approach for Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae is a common pathogen that causes community-acquired pneumonia. In the past, M. pneumoniae was sensitive to macrolide antibiotics, and M. pneumoniae pneumonia (MPP) was usually a benign and self-limiting disease. However, despite use of the appropriate antibiotics, persistent fever and clinical deterioration may occur, leading to severe disease. Two major complicated conditions that may be clinically encountered are macrolide-resistant MPP and refractory MPP. Regarding the epidemics in Taiwan, before 2017, the mean rate of macrolide resistance was below 30%. Notably, since 2018, the prevalence of macrolide-resistant MPP in Taiwan has increased rapidly. Macrolide-resistant MPP shows persistent fever and/or no radiological regression to macrolide antibiotics and may even progress to severe and complicated pneumonia. Tetracyclines (doxycycline or minocycline) or fluoroquinolones are alternative treatments for macrolide-resistant MPP. Refractory MPP is characterized by an excessive immune response against the pathogen. In this context, corticosteroids have been suggested as an immunomodulator for downregulating the overactive host immune reaction. Overuse of macrolides may contribute to macrolide resistance, and thereafter, an increase in macrolide-resistant MPP. Delayed effective antimicrobial treatment is associated with prolonged and/or more severe disease. Thus, the appropriate prescription of antibiotics, as well as the rapid and accurate diagnosis of MPP, is important. The exact starting point, dose, and duration of the immunomodulator are yet to be established. We discuss these important issues in this review.

Reactive infectious mucocutaneous eruption: Mycoplasma pneumoniae-induced rash and mucositis and other parainfectious eruptions

Mycoplasma pneumoniae-induced rash and mucositis is the most accurate diagnosis for patients with blistering mucocutaneous disease provoked by an infection. Recent literature suggests expansion of the name is required, as other infections have caused a clinically similar presentation. This review provides a concise update on current understanding of M. pneumoniae-induced rash and mucositis and other reactive infectious mucocutaneous eruptions.

Altered chemokine profile in Refractory Mycoplasma pneumoniae pneumonia infected children

BACKGROUND

Mycoplasma pneumoniae is one of the major pathogens causing community-acquired pneumonia in children. Although usually self-limited, Mycoplasma pneumoniae pneumonia (MPP) may lead to complicated morbidity that can even be life-threatening. Upon MPP infection, alveolar macrophage becomes attracted and activated and will induce subsequent cytokine and chemokine reaction. Refractory Mycoplasma pneumoniae pneumonia (RMPP) is manifested by clinical or radiological deterioration despite proper antibiotic therapy. RMPP is characterized with excessive inflammation and may need subsequent glucocorticoid treatment.

AIM

The aim of this study was to investigate the change of plasma chemokines in non-refractory Mycoplasma pneumoniae pneumonia (NRMPP) and RMPP before and after antibiotic or methylprednisolone treatment.

METHOD

A total of 42 children with MPP were enrolled in this study. Plasma specimens were collected at admission and one to two weeks after antibiotic or methylprednisolone treatment with declined fever. Plasma specimens were then indicated to chemokines detection.

RESULTS

Mycoplasma pneumoniae pneumonia altered the chemokine profile through the observation of decreased plasma M1 related chemokines (CCL2, CCL8 and CXCL10) and increased M2 related chemokines (CCL17 and CCL22) after treatment.When the patients were divided into RMPP and NRMPP groups and the chemokines before treatment were compared, the RMPP group showed higher CXCL10 but lower CCL3 and CCL11 than the NRMPP group.

CONCLUSION

Unique changes in macrophage related chemokines is observed in the course of MPP infection. NRMPP and RMPP infection in children showed distinct manifestation in chemokine profiles.

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.

Meta-analysis of the Clinical Efficacy and Safety of High- and Low-dose Methylprednisolone in the Treatment of Children With Severe Mycoplasma Pneumoniae Pneumonia

BACKGROUND

Mycoplasma pneumoniae pneumonia is generally a self-limiting disease, but it can develop into severe Mycoplasma pneumoniae pneumonia (SMPP). Immunologic mechanisms are thought to play an important role in the pathogenesis of SMPP. Therefore, the use of systemic glucocorticoids may have beneficial effects. However, to date, the use of glucocorticoid therapy in SMPP is limited to small case series, and the glucocorticoid dosage for children with SMPP has not been established.

METHODS

Here, we used a meta-analysis method to collect data from randomized control trials of different doses of methylprednisolone in SMPP to assess the safety and efficacy of treatment with low- versus high-dose methylprednisolone in children with SMPP.

RESULTS

We included 13 Chinese randomized control trials that included 1049 children. The high- and low-dose groups were comprised of 524 and 525 children, respectively. The high-dose group was significantly more effective than the low-dose group in clinical efficacy [risk ratio = 1.30, 95% confidence interval (CI) (1.23, 1.38), P < 0.05]. In addition, compared with low-dose methylprednisolone, high-dose methylprednisolone significantly shortened hospital stays and antipyretic therapy, pulmonary rales disappearance, cough disappearance and pulmonary shadow absorption times. There was no significant difference in adverse events between the high- and low-dose groups: risk ratio= 0.85, 95% CI (0.53, 1.36), P > 0.05.

CONCLUSIONS

We conclude that high-dose methylprednisolone is effective in the treatment of SMPP without increasing the incidence of adverse reactions.

Annual and seasonal patterns in etiologies of pediatric community-acquired pneumonia due to respiratory viruses and Mycoplasma pneumoniae requiring hospitalization in South Korea

Background

Community–acquired pneumonia (CAP) is one of the leading worldwide causes of childhood morbidity and mortality. Its disease burden varies by age and etiology and is time dependent. We aimed to investigate the annual and seasonal patterns in etiologies of pediatric CAP requiring hospitalization.

Methods

We conducted a retrospective study in 30,994 children (aged 0–18 years) with CAP between 2010 and 2015 at 23 nationwide hospitals in South Korea. Mycoplasma pneumoniae (MP) pneumonia was clinically classified as macrolide-sensitive MP, macrolide-less effective MP (MLEP), and macrolide-refractory MP (MRMP) based on fever duration after initiation of macrolide treatment, regardless of the results of in vitro macrolide sensitivity tests.

Results

MP and respiratory syncytial virus (RSV) were the two most commonly identified pathogens of CAP. With the two epidemics of MP pneumonia (2011 and 2015), the rates of clinical MLEP and MRMP pneumonia showed increasing trends of 36.4% of the total MP pneumonia. In children < 2 years of age, RSV (34.0%) was the most common cause of CAP, followed by MP (9.4%); however, MP was the most common cause of CAP in children aged 2–18 years of age (45.3%). Systemic corticosteroid was most commonly administered for MP pneumonia. The rate of hospitalization in intensive care units was the highest for RSV pneumonia, and ventilator care was most commonly needed in cases of adenovirus pneumonia.

Conclusions

The present study provides fundamental data to establish public health policies to decrease the disease burden due to CAP and improve pediatric health.

Mycoplasma pneumoniae pneumonia associated thrombosis at Beijing Children's hospital

Background

With the increase of awareness of mycoplasma pneumoniae pneumonia (MPP), we found thrombosis in severe MPP (SMPP) was not rare. The aim of the study was to investigate the clinical characteristics, treatment, and long-term prognosis of MPP-associated thrombosis.

Methods

We retrospectively reviewed the medical records of 43 children with MPP-associated thrombosis between January 2013 and June 2019 at Beijing Children’s Hospital. The results of blood coagulation studies, autoimmune antibody, thrombophilia screening, contrast-enhanced lung computed tomography, echocardiography, and blood vessel ultrasonography were analyzed, as were treatment outcomes.

Results

Forty-two patients were diagnosed with SMPP. D-dimer was higher than 5.0 mg/L in 58.1% (25/43) of patients. The mean D-dimer level was 11.1 ± 12.4 mg/L. Anticardiolipin-IgM was positive in 60.0% of patients, β2-glycoprotein-IgM in 64.0%, and lupus anticoagulant in 42.1%. Chest imaging revealed pulmonary consolidation with lobe distribution in all patients (2/3–1 lobe in 10 patients, > 1 lobe in 29 patients). In our experience, thrombosis can occur in a vessel of any part of the body, and it can be initially detected as late as 31 days after disease onset. Thrombosis in the brain and abdomen can occur early, at 5 days after disease onset. Pulmonary vessels were the most commonly involved sites in the current study, and accordingly chest pain was the most common symptom (32.6%), followed by neurological symptoms (14.0%) and abdominal pain (9.3%). Thirty-five percent of patients were asymptomatic with regard to thrombosis. All patients underwent anticoagulant therapy, and thrombus absorption took > 3 months in most patients. All patients were followed until October 2019, at which time 41 were asymptomatic and 2 had mild recurrent cough.

Conclusions

SMPP with pulmonary consolidation (> 2/3 lobe) was the most strongly associated risk factor for thrombosis. Thrombosis-associated symptoms may be subtle, even absent. Elevated D-dimer, specifically > 11.1 mg/L (even > 5.0 mg/L), would assist in the early diagnosis of thrombosis. The long-term prognosis of thrombosis was good after timely administration of anticoagulant therapy.

Efficacy of glucocorticoids for the treatment of macrolide refractory mycoplasma pneumonia in children: meta-analysis of randomized controlled trials

Background

Mycoplasma pneumoniae is one of the most common pathogens causing community acquired pneumonia in children. Although the rate of macrolide-refractory Mycoplasma pneumoniae (MRMP) has increased, systemic glucocorticoids as a treatment option has not been validated yet. The purpose of this study was to assess the efficacy of glucocorticoids add-on in the treatment of MRMP in children through systematic review and meta-analysis.

Methods

Data sources

A systematic literature search was conducted using ten electronic bibliographic databases including English, Korean, Chinese and Japanese languages, up to March 8, 2018.

Study selection

The study was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and selected randomized control trials which compared the efficacy of glucocorticoids add-on to macrolide in the treatment of MRMP in children.

Data extraction

Two independent reviewers extracted: primary outcomes as hospital days, fever duration, and change in C-reactive protein (CRP) and main analysis was performed through meta-analysis with random effects model.

Results

Twenty-four unique randomized controlled trials met the inclusion criteria. The mean length of hospital stay in glucocorticoids treatment group was significantly shorter than that in conventional macrolide-treatment group (Weighted mean difference (WMD) = − 4.03 days). The mean length of fever duration was significantly shorter in the glucocorticoid treatment group in comparison with the conventional treatment group (WMD = -3.32 days). Level of CRP after treatment was significantly lower in the glucocorticoid treatment group than that in the conventional treatment group (WMD = -16.03). Sensitivity analysis and subgroup analysis showed no significant improvement in heterogeneity. As limitations of the study, most of the studies included were from a single country and we were unable to control for heterogeneity across interventions, lack of standardized measures, and different time points of assessments across studies.

Conclusions

Glucocorticoid add-on treatment for MRMP can significantly shorten the duration of fever and hospital stay and decrease the level of CRP. These results should be confirmed by adequately powered studies in the future.

Comparison of azithromycin and erythromycin in the treatment of mycoplasma pneumonia in children

Objective:

To study and compare the clinical effects of azithromycin and erythromycin on children with mycoplasma pneumonia.

Methods:

Total 132 children with mycoplasma pneumonia who were admitted to our hospital between November 2017 and September 2018 were selected as the research subjects. All the children were divided into an observation group and a control group according to random number table, 66 each. The observation group was treated with azithromycin, while the control group was treated with erythromycin. The therapeutic effect, incidence of adverse reactions and disappearance time of clinical symptoms were compared between the two groups.

Results:

The total efficacy of the observation group was 98.04%, and that of the control group was 74.51%; there was a significant difference (X²=7.184, P=0.007). The incidence of adverse reactions in the observation group was 15.69%, significantly lower than that in the control group (41.18%) (X²=6.376, P=0.002). The disappearance of fever, cough, rale and X ray shadow of the observation group was significantly earlier than that of the control group, and the difference was statistically significant (P<0.05).

Conclusion:

Compared with erythromycin, azithromycin is more effective in the treatment of mycoplasma pneumonia in children. Azithromycin can further shorten the improvement time of clinical symptoms and signs and has few adverse reactions and high safety. It is worth clinical application.

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

Background

An 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.

Methods

We 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.

Results

The 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 10^{7.46 ± 0.93} and 10^{4.86 ± 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).

Conclusion

MP 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.

Predictive Model for Discrimination of Tuberculous Pleural Effusion From Severe Mycoplasma pneumoniae Pneumonic Effusion in Children

BACKGROUND

Tuberculous pleural effusion (TPE) is often misdiagnosed as severe Mycoplasma pneumoniae pneumonic effusion (SMPPE) in children at early stage. The aim of this study was to develop a predictive model based on clinical and laboratory indices to make accurate differential diagnosis.

METHODS

Patients included in this study were 167 children (83 patients with TPE and 84 with SMPPE), containing 117 patients for predictive model development and 50 patients for external validation. Multivariate logistic regression analysis was conducted to select potentially useful characteristics for discrimination of TPEs. External validation was performed for model evaluation.

RESULTS

Multivariate analysis revealed that blood neutrophils and serum lactate dehydrogenase were significant independent factors to discriminate between TPEs and SMPPEs. The results indicated that blood neutrophils ≤69.6% and concentration of serum lactate dehydrogenase ≤297 U/L were the extremely important discrimination factors of TPEs. The area under the receiver operating characteristic curve of the model was 0.9839. The accuracy rate, sensitivity and specificity of the model were 94.02%, 98.28% and 89.83%, respectively. Meanwhile, the accuracy rate of the external validation from the 50 patients was 94.0%.

CONCLUSIONS

Applying a predictive model with clinical and laboratory indices can facilitate the differential diagnosis of TPE from SMPPE in children, which seems helpful when a microbiologic or histologic diagnosis of pleural tuberculosis could not be established.

In vitro susceptibility test of Xiao'er Feire Kechuan Oral Solution to Mycoplasma pneumoniae

The aim of this study was to evaluate the inhibitory effect of antibiotics and Xiao'er Feire Kechuan Oral Solution on Mycoplasma pneumoniae (MP) clinical isolates.Twenty clinical isolates containing A-to-G transition at position 2063 and 10 clinical isolates without mutations in 23S rRNA V regions were randomly selected. The international standard strain FH was chosen as control strain. The minimum inhibitory concentration (MIC) of macrolide, quinolones, tetracycline, and Xiao'er Feire Kechuan Oral Solution to MP clinical isolates were performed using broth microdilution method.In vitro antibiotic susceptibility test of MP clinical isolates showed that MP showed high resistance to macrolide antibiotics (erythromycin and azithromycin); MIC of both were more than 64 μg/mL. The MICs of erythromycin and azithromycin for clinical isolates without mutations in 23S rRNA V regions were ≤0.5 μg/mL. The MICs of tetracycline and levofloxacin for all clinical isolated strains were ≤2.0 μg/mL and ≤1.0 μg/mL, respectively. The MIC of Xiao'er Feire Kechuan Oral Solution was 13.828∼6.914 mg/mL.In vitro, the drug resistance of MP to macrolide antibiotics is higher, MP clinical isolates are sensitive to tetracycline and levofloxacin, and Xiao'er Feire Kechuan Oral Solution also has a certain inhibitory effect on the macrolide-resistant MP.

Early Corticosteroid Therapy for Mycoplasma pneumoniae Pneumonia Irrespective of Used Antibiotics in Children

Antibiotics’ effect on Mycoplasma pneumoniae (MP) infection still remains controversial. A prospective study of 257 children with MP pneumonia during a recent epidemic (2015–2016) was conducted. All MP pneumonia patients were treated with corticosteroids within 24–36 h after admission. Initially, oral prednisolone (1 mg/kg) or intravenous methylprednisolone (IVMP; 1–2 mg/kg) was administered for mild pneumonia patients, and IVMP (5–10 mg/kg/day) for severe pneumonia patients. If patients showed a persistent fever for 36–48 h or disease progression, additive IVMP (5 mg/kg or 10 mg/kg) was given. Thirty-three percent of patients received only a broad-spectrum antibiotic without a macrolide. The mean age and the male-to-female ratio was 5.6 ± 3.1 years and 1:1, respectively. Seventy-four percent of patients showed immediate defervescence within 24 h, and 96% of patients showed defervescence within 72 h with improvements in clinical symptoms. Three percent of patients (8/257) who received additive IVMP also showed clinical improvement within 48 h without adverse reactions. There were no clinical or laboratory differences between patients treated with a macrolide (n = 172) and without (n = 85). Early corticosteroid therapy might reduce disease morbidity and prevent disease progression in MP pneumonia patients without side effects, and antibiotics may have limited effects on MP infection.

Comparison of multiple detection methods of Mycoplasma pneumoniae antibody for the early diagnosis of pediatric mycoplasma pneumonia

Mycoplasma pneumoniae pneumonia (MPP) is a common disease in infants and young children. MPP can also be a potential cause of healthcare-associated pneumonia. However, it is challenging to make an accurate diagnosis in a timely fashion. Our goal is to determine the assay consistencies of acridinium ester chemiluminescence immunoassay (AECLIA) and gelatin particle agglutination (GPA) test for the detection of Mycoplasma pneumoniae (MP) antibody. In this study, a total of 1404 children with suspected MPP were enrolled. Among them, 130 were diagnosed as MPP positive by mycoplasma culture, and 186 were negative. MP antibodies were detected by AECLIA, enzyme-linked immunosorbent assay (ELISA) and GPA. Consistency rates, differences among assays, and diagnosis performance were compared for the three methods. The independent χ2 test results of AECLIA and ELISA for the detection of MP-IgG and MP-IgM antibodies were χ2 = 29.210, P < 0.001; χ2 = 9.081, P = 0.017, respectively, suggesting that the two detection methods are well correlated. Similar analyses were done for the comparison of AECLIA and GPA as well as the comparison of ELISA and GPA. The positive rates of these methods agree with epidemiology data and have good consistency. Thus, AECLIA with a much shorter assay time could be a better option for the screening of MPP.

Independent predictors for longer radiographic resolution in patients with refractory Mycoplasma pneumoniae pneumonia: a prospective cohort study

OBJECTIVES

To examine prospectively the radiographic clearance of refractory Mycoplasma pneumoniae pneumonia (RMPP) in immunocompetent children, and to identify independent predictors of time to complete radiographic resolution in patients with RMPP.

DESIGN

A prospective cohort study.

SETTING

Children's Hospital of Soochow University, China.

PARTICIPANTS

A total of 187 patients with RMPP treated with bronchoscopy were prospectively enrolled in the study between January 2012 and December 2015.

METHODS

Serial chest radiographs were obtained after discharge every 4 weeks up to a maximum of 24 weeks after diagnosis or until large infiltration on chest radiographs had resolved. Multivariate logistic regression was performed to identify independent predictors of time to complete radiographic resolution.

RESULTS

Of the 187 patients with RMPP, bronchial mucus plug formation was detected in 73 (39.0%). C reactive protein (CRP) ≥50 mg/L, lactate dehydrogenase (LDH) ≥480 U/L, total fever duration ≥10 days and presence of mucus plugs were associated with longer time to radiographic clearance (all p<0.01). Compared with children without mucus plugs, those with mucus plugs were significantly more likely to have longer time to radiographic clearance (adjusted OR: 11.5; 95% CI 2.5 to 45.7; p<0.01).

CONCLUSION

Clinicians might use duration of fever, CRP, LDH and presence of mucus plugs as parameters to identify children at a longer time to radiographic clearance in patients with RMPP.

Therapeutic Efficacy and Safety of Prolonged Macrolide, Corticosteroid, Doxycycline, and Levofloxacin against Macrolide-Unresponsive Mycoplasma pneumoniae Pneumonia in Children

BACKGROUND

We aimed to compare the therapeutic efficacy of prolonged macrolide (PMC), corticosteroids (CST), doxycycline (DXC), and levofloxacin (LFX) against macrolide-unresponsive Mycoplasma pneumoniae (MP) pneumonia in children and to evaluate the safety of the secondary treatment agents.

METHODS

We retrospectively analyzed the data of patients with MP pneumonia hospitalized between January 2015 and April 2017. Macrolide-unresponsiveness was clinically defined with a persistent fever of ≥ 38.0°C at ≥ 72 hours after macrolide treatment. The cases were divided into four groups: PMC, CST, DXC, and LFX. We compared the time to defervescence (TTD) after secondary treatment and the TTD after initial macrolide treatment in each group with adjustment using propensity score-matching analysis.

RESULTS

Among 1,165 cases of MP pneumonia, 190 (16.3%) were unresponsive to macrolides. The proportion of patients who achieved defervescence within 48 hours in CST, DXC, and LFX groups were 96.9% (31/33), 85.7% (12/14), and 83.3% (5/6), respectively. The TTD after initial macrolide treatment did not differ between PMC and CST groups (5.1 vs. 4.2 days, P = 0.085), PMC and DXC groups (4.9 vs. 5.7 days, P = 0.453), and PMC and LFX groups (4.4 vs. 5.0 days, P = 0.283). No side effects were observed in the CST, DXC, and LFX groups.

CONCLUSION

The change to secondary treatment did not show better efficacy compared to PMC in children with macrolide-unresponsive MP pneumonia. Further studies are needed to guide appropriate treatment in children with MP pneumonia.

Serum lactate dehydrogenase isoenzymes 4 plus 5 is a better biomarker than total lactate dehydrogenase for refractory Mycoplasma pneumoniae pneumonia in children

Although usually self-limiting, Mycoplasma pneumoniae pneumonia (MPP) may lead to clinical or radiological deterioration despite macrolide antibiotic therapy, resulting in the development of refractory MPP (RMPP). Corticosteroids have been used to treat RMPP with beneficial effects. Serum lactate dehydrogenase (LDH) is a suggested biomarker for the use of steroid therapy. Since serum LDH is a non-specific marker and elevated in many inflammatory processes, this study investigates the predicting level of LDH isoenzymes for RMPP. Fifty-four children with non-refractory M. pneumoniae pneumonia (NRMPP) and 16 children with RMPP were enrolled in this study. In comparison to the NRMPP group, the RMPP group showed significantly higher levels of serum LDH. Concerning LDH isoenzymes, the RMPP group showed significantly lower proportions of LDH1 and LDH2, while higher LDH4 and LDH5 percentage. Receiver operating characteristic curve analysis showed that the area under the curve for the total LDH data was 0.812 with a cut-off of 408 IU/L (sensitivity of 75.0%, specificity of 72.2%). The areas under the curve for LDH4, LDH5, and [LDH4 + LDH5] were estimated to be 0.813, 0.818, and 0.829, respectively. The threshold for [LDH4 + LDH5] was estimated to be 109.4 IU/L (sensitivity, 75.0%; specificity, 87.0%). These results indicate that for the initiation of corticosteroid therapy, serum [LDH4 + LDH5] level is a more sensitive biomarker than total LDH.

Low-dose versus high-dose methylprednisolone for children with severe Mycoplasma pneumoniae pneumonia (MCMP): Study protocol for a randomized controlled trial

BACKGROUND

Severe Mycoplasma pneumoniae pneumonia (MPP) may develop with long-term pulmonary outcomes despite treatment with macrolides. Combined treatment with glucocorticoids can improve this outcome, though the optimal dosage is unknown. The aim of this study was to investigate the effects of low- and high-dose methylprednisolone in reducing the percentage of long-term pulmonary outcomes for children with severe MPP.

METHODS

A randomized, single-blind, parallel-controlled, multicenter clinical trial, methylprednisolone for children with severe M. pneumoniae pneumonia (MCMP), is being conducted in China. Pediatric patients (≤18 years of age, expected number = 402) admitted to the hospital with a clinical diagnosis of severe MPP and fulfilling inclusion and exclusion criteria are randomized (ratio of 1:1) to either a low-dose (2 mg/kg/d) or high-dose (10 mg/kg/d) methylprednisolone treatment group for 3 days followed by tapering of methylprednisolone over 12 days and combined with azithromycin. The primary composite outcome will be incidence of atelectasis, bronchiectasis, or bronchiolitis obliterans at 6-months after treatment. Secondary outcomes include recovery time of patient temperature, proportion of pulmonary lesions absorbed, changes of mucosa identified by bronchoscopy, length of hospital stay, pulmonary function and number of participant(s) needing intensive care. Assessments will be made at baseline, post-treatment and at 1-month, 3-month and 6-month follow-ups.

DISCUSSION

This is the first randomized clinical trial designed to evaluate the safety and efficacy of low- versus high-dose methylprednisolone for reducing long-term pulmonary outcomes in pediatric patients with severe MPP. The results of this study will provide scientific evidence to guide clinical practice for the treatment of severe MPP. Trial registration: This study is registered at ClinicalTrials.gov (NCT02303587).

Transcriptome Analysis of Bronchoalveolar Lavage Fluid From Children With Mycoplasma pneumoniae Pneumonia Reveals Natural Killer and T Cell-Proliferation Responses

Background

Mycoplasma pneumoniae pneumonia (MPP) is one of the most common community-acquired pneumonia; this study is to explore the immune-pathogenesis of children MPP.

Methods

Next-generation transcriptome sequencing was performed on the bronchoalveolar lavage fluid cells from six children with MPP and three children with foreign body aspiration as control. Some of the results had been validated by quantitative real-time PCR in an expanded group of children.

Results

Results revealed 810 differentially expressed genes in MPP group comparing to control group, of which 412 genes including RLTPR, CARD11 and RASAL3 were upregulated. These upregulated genes were mainly enriched in mononuclear cell proliferation and signaling biological processes. Kyoto encyclopedia of genes and genomes pathway analysis revealed that hematopoietic cell linage pathway, natural killer cell-mediated cytotoxicity pathway, and T cell receptor signaling pathway were significantly upregulated in MPP children. In addition, significant alternative splicing events were found in GNLY and SLC11A1 genes, which may cause the differential expressions of these genes.

Conclusion

Our results suggest that NK and CD8+ T cells are over activated and proliferated in MPP children; the upregulated IFNγ, PRF1, GZMB, FASL, and GNLY may play important roles in the pathogenesis of children MPP.

Mycoplasma pneumoniae: A Potentially Severe Infection

Mycoplasma pneumoniae infections remain one of the most common etiologies of community-acquired pneumonia (CAP). The clinical presentation and manifestations vary widely and can affect all organs of the body. Diagnosis is challenging because there are no constant findings in physical exams or laboratory or radiological assessments that indicate Mycoplasma pneumoniae pneumonia, and specific diagnostic tools are not readily available. Extrapulmonary manifestations and severe pulmonary manifestations can lead to long-term sequelae. The increasing emergence of Mycoplasma pneumoniae that is resistant to macrolides in some areas of the world and increased world travel could add to the difficulty of controlling and treating Mycoplasma pneumoniae infections. We present a concise and up-to-date review of the current knowledge of Mycoplasma pneumoniae pneumonia.

Recent trends in practice patterns and impact of corticosteroid use on pediatric Mycoplasma pneumoniae-related respiratory infections

BACKGROUND

Mycoplasma pneumoniae is a major pathogen causing community-acquired pneumonia/bronchitis in children, and macrolide-resistant strains are increasing in East Asian countries. Recent practice patterns, especially for antibiotic selection, and benefits of corticosteroid treatment in pediatric Mycoplasma pneumoniae infections remain unclear.

METHODS

Using the Japanese Diagnosis Procedure Combination inpatient database, we analyzed recent trends in antibiotic selection and corticosteroid use for pediatric Mycoplasma pneumoniae-related respiratory infections, using multivariable mixed effects logistic regressions. In addition, we compared hospital utilization and readmission between children who received corticosteroids and those who did not, using propensity-score matching and instrumental variable analyses.

RESULTS

Overall, 51,633 inpatients were identified. From 2010 to 2014, the use of macrolides and lincosamides decreased from 62.8% to 50.6% and from 25.6% to 13.7% respectively (P_trend < 0.001), whereas fluoroquinolone use increased from 4.6% to 22.6% (P_trend < 0.001). Tetracycline use did not demonstrate a significant change in trend. Propensity score matching analysis showed that hospital stay in the steroid group was 0.90 days longer than in the non-steroid group (95% confidence interval, 0.84-0.96). Total hospitalization cost was higher in the steroid compared to the non-steroid group (57.6 US dollars; 95% CI, 48.8-66.8). A significant difference in 30-day readmission risk was observed between the steroid (1.6%) and non-steroid (1.2%) groups (risk difference 0.4%; 95% CI, 0.1-0.7%). Similar results were observed on instrumental variable analyses.

CONCLUSIONS

Increasing trends in fluoroquinolone use and decreasing trends in macrolide use were observed. Our study did not prove the benefits of corticosteroid use. Further studies are required to confirm the clinical benefits of corticosteroid treatment.

Low Bacterial Co-infection Invalidates the Early Use of Non-anti-Mycoplasma pneumoniae Antibiotics in Pediatric Refractory Mycoplasma pneumoniae Pneumonia Patients

Background: Childhood refractory mycoplasma pneumoniae (MP) pneumonia (RMPP) is a lung disease with elevated level of C-reactive protein and severe clinical and radiological deterioration. Whether bacterial co-infection contributes to disease of RMPP and whether inclusion of non-anti-MP antibiotics in treatment regimen would benefit RMPP patients remains elusive. Methods: We retrospectively reviewed the medical records of 675 RMPP children. Traditional bacterial culture and next generation sequencing (NGS) were used to detect bacteria in bronchoalveolar lavage fluid in all the 675 patients and 18 patients respectively. Antibiotics used and clinical outcomes were analyzed along with other clinical measurements. Results: Positive bacterial cultures were only found in 18 out of 675 cases (2.67%) and NGS analyses of another 18 cases did not revealed positive bacterial infection, which were consistent with the results of bacterial cultures. Non-anti-MP antibiotics were utilized in 630 cases (93.33%), even last-line antibiotics, such as glycopeptides or carbapenems, were frequently used. Conclusion: Bacterial co-infection in RMPP was rare and non-anti-MP antibiotics didn't show any efficacy for early treatment of RMPP patients, which may provide a rationale for restricting the use of non-anti-MP antibiotics in RMPP patients and preventing antibiotic resistance globally.

Adjunctive corticosteroid therapy for inpatients with Mycoplasma pneumoniae pneumonia

Background

There is conflicting evidence regarding the benefit of adjunctive corticosteroid therapy in patients with Mycoplasma pneumoniae pneumonia. We hypothesised that corticosteroid therapy could reduce mortality and length of stay (LOS) in such patients.

Methods

Adult patients with M. pneumoniae pneumonia from January 2010 to December 2013 were identified from the Japanese Diagnosis Procedure Combination inpatient database. The effects of low-dose and high-dose corticosteroid therapies on mortality, LOS, drug costs and hyperglycaemia requiring insulin treatment were evaluated using propensity score analyses.

Results

Eligible patients (n = 2228) from 630 hospitals were divided into no-corticosteroid (n = 1829), low-dose corticosteroid (n = 267) and high-dose corticosteroid (n = 132) groups. The propensity score-matched pairs were generated from no-corticoid and low-dose corticoid groups (251 pairs), or no-corticoid and high-dose corticosteroid groups (120 pairs). Adjunctive corticosteroid therapy did not decrease 30-day mortality. In addition, both low-dose and high-dose corticosteroid therapies were associated with increases in LOS. Furthermore, hyperglycaemia requiring insulin treatment and drug cost increased with corticosteroid use.

Conclusions

Adjunctive treatment with low-dose or high-dose corticosteroids may not be beneficial in M. pneumoniae pneumonia.