The Clinical Characteristics and Predictors of Refractory Mycoplasma pneumoniae Pneumonia in Children

Prediction of Bronchial Mucus Plugs Formation in Patients with Refractory Mycoplasma Pneumoniae Pneumonia

We aimed to find the relationship between the clinical characteristics and mucus plug formation and developed models to predict mucus plug formation in refractory Mycoplasma pneumoniae pneumonia (RMPP) infection. Methods: RMPP patients treated with bronchoscopy were retrospectively enrolled in the study between November 2011 and November 2015. Multivariate logistic regression was performed to identify independent predictors of mucus plug formation. Results: Of the 173 RMPP patients enrolled, the mucus plug group accounted for 82 (47.4%) cases. Multivariate logistic regression analysis identified age, fever duration, C-reactive protein (CRP) and lactic dehydrogenase (LDH) as independent risk factors for mucus plug. We assigned one point for age, length of fever and CRP and two points for LDH. Using this predicted score, we identified patients with mucus plug with 71.8% sensitivity and 78.9% specificity. Conclusions: Our predictive models based on demographic and laboratory variables accurately predicted mucus plug formation in initial treatment of patients with RMPP.

Transcriptome analysis of bronchoalveolar lavage fluid from children with severe Mycoplasma pneumoniae pneumonia reveals novel gene expression and immunodeficiency

Background

A growing number of severe Mycoplasma pneumoniae pneumonia (MPP) cases have been reported recently. However, the pathogenesis of severe MPP is not clear. In the current study, transcriptome sequencing was used to identify gene expression and alternative splicing profiles to provide insights into the pathogenesis of severe MPP.

Methods

RNAs of bronchoalveolar lavage fluid (BALF) samples from three severe MPP children and three mild MPP children were analyzed respectively by deep sequencing followed by computational annotation and quantification.

Results

The gene expression analysis revealed 14 up-regulated and 34 down-regulated genes in severe MPP children comparing to mild MPP children. The top 10 most up-regulated genes were IGHV1-69, CH17-472G23.1, ATP1B2, FCER2, MUC21, IL13, FCRLB, CLEC5A, FAM124A, and INHBA. The top 10 most down-regulated genes were OSTN-AS1, IL22RA2, COL3A1, C1orf141, IGKV2-29, RP11-731F5.2, IGHV4-4, KIRREL, DNASE1L3, and COL6A2. Clustering analysis revealed similar expression pattern of CLEC5A, IL13, FCER2, and FLT1. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed changes related to primary immunodeficiency in severe MPP children comparing to mild MPP children; the pathway involves CD19, TNFRSF13C, CD79A, and AICDA genes. Among the differentially expressed genes, significant alternative splicing events were found in FCER2 and FCRLA.

Conclusions

The current study on RNA sequencing provides novel insights into the pathogenesis of severe MPP in terms of gene expression and alternative splicing. The up-regulation of IL13, FCER2, FLT1, and CLEC5A and the down-regulation of CD79A, AICDA, CD19, and TNFRSF13C may contribute to the pathogenesis of severe MPP. The differential expressions of FCER2 and FCRLA could be due to their alternative splicing.

Electronic supplementary material

The online version of this article (doi:10.1186/s40246-017-0101-y) contains supplementary material, which is available to authorized users.

The clinical characteristics of corticosteroid-resistant refractory Mycoplasma Pneumoniae pneumonia in children

To analyze the clinical characteristics of corticosteroid-resistant refractory Mycoplasma pneumoniae pneumonia (RMPP) and explore the related factors that predict corticosteroid-resistant RMPP. Retrospective analysis of 183 children with RMPP in our hospital admitted between January 1, 2012, and December 31, 2014 was performed. Of the 183 RMPP cases, 36 (19.7%) were corticosteroid-resistant RMPP cases. Corticosteroid-resistant RMPP cases had a longer duration of fever and hospitalization compared with corticosteroid-sensitive RMPP cases (P < 0.05). The radiographic findings of 123 (83.7%) cases of corticosteroid-sensitive RMPP apparently resolved after one week of corticosteroid treatment compared with 4 (11.1%) corticosteroid-resistant RMPP cases that had apparently resolution (P < 0.01). Twenty-four (75%) corticosteroid-resistant RMPP patients who received bronchoscopy had mucus plug formation while none of the corticosteroid-sensitive RMPP patients had mucus plug formation (P < 0.05). Multiple logistic regression analysis showed that duration of fever ≥11 days, percentage of lymphocytes ≤32%, CRP ≥48.73 mg/L and LDH ≥ 545.7 U/L were significant predictors of corticosteroid-resistant RMPP. Patients with corticosteroid-resistant RMPP had more severe presentations and more serious radiological findings. Clinicians might use the parameters of duration of fever, CRP, LDH and proportion of lymphocytes to identify children at higher risk of corticosteroid-resistant RMPP.

Cytokines as the good predictors of refractory Mycoplasma pneumoniae pneumonia in school-aged children

Excessive immune response against pathogens may play an important role in refracory Mycoplasma pneumoniae pneumonia (RMPP). The aim of this study was to elucidate the associations between cytokines and the prediction of RMPP in school-aged patients. Retrospective analysis was performed on school-aged children with Mycoplasma pneumoniae pneumonia (MPP) hospitalized in our hospital between January 1, 2011 and December 31, 2015. The clinical charcteristics, including the cytokines in serum between the RMPP group and the general Mycoplasma pneumoniae pneumonia (GMPP) group were compared and the predictive values of RMPP were explored. Of total 180 patients, 115 patients were in the GMPP group, 65 were in the RMPP group. We found the levels of cytokines, including nterleukin (IL)-6, IL-10, interferon gamma (IFN-γ) in RMPP group were significantly higher than those in GMPP group (P < 0.01). In ROC curve analysis, IL-10 and IFN-γ were useful for differentiating patients with RMPP from those with GMPP. Logistic regression analysis showed that the IL-10 ≥ 3.65 pg/ml and IFN-γ ≥ 29.05 pg/ml were significant predictors regarding to RMPP. Additionally, a positive correlation between serum IL-10 and IFN-γ concentrations was observed. Conclusions: IL-10 and IFN-γ could be used as the good predictors of RMPP in school-aged children.