Serum cytokine profile contributes to discriminating M. pneumoniae pneumonia in children

Serum IL-17A and IL-6 in paediatric Mycoplasma pneumoniae pneumonia: implications for different endotypes

Paediatric Mycoplasma pneumoniae pneumonia (MPP) is a heterogeneous disease with a diverse spectrum of clinical phenotypes. No studies have demonstrated the relationship between underlying endotypes and clinical phenotypes as well as prognosis about this disease. Thus, we conducted a multicentre prospective longitudinal study on children hospitalized for MPP between June 2021 and March 2023, with the end of follow-up in August 2023. Blood samples were collected and processed at multiple time points. Multiplex cytokine assay was performed to characterize serum cytokine profiles and their dynamic changes after admission. Cluster analysis based on different clinical phenotypes was conducted. Among the included 196 patients, the levels of serum IL-17A and IL-6 showed remarkable variabilities. Four cytokine clusters based on the two cytokines and four clinical groups were identified. Significant elevation of IL-17A mainly correlated with diffuse bronchiolitis and lobar lesion by airway mucus hypersecretions, while that of IL-6 was largely associated with lobar lesion which later developed into lung necrosis. Besides, glucocorticoid therapy failed to inhibit IL-17A, and markedly elevated IL-17A and IL-6 levels may correlate with lower airway obliterans. Our study provides critical relationship between molecular signatures (endotypes) and clustered clinical phenotypes in paediatric patients with MPP.

Performance of interferon-gamma levels may lead to earlier diagnosing macrophage activation syndrome complicating systemic juvenile idiopathic arthritis

Macrophage activation syndrome (MAS) is a severe, potentially fatal complication of rheumatic diseases, predominantly in systemic juvenile idiopathic arthritis (SJIA), and is considered as an autoinflammatory disease. Specific cytokine profiles could play a pivotal role in this inflammatory response. Gram-negative bacteremia, bacterial pneumonia, Kawasaki disease, and active SJIA exhibited similar cytokine profiles with elevated interleukin-6 (IL-6) and/or IL-10, further suggesting a correlation between them. Only when JIA is complicated by MAS can increased interferon-γ (IFN-γ) levels be observed. Therefore, increased serum IFN-γ levels could contribute to early diagnosing MAS in patients with SJIA in combination with other variables such as serum ferritin. A prospective multi-center study will be performed to further confirm the role of IFN-γ in the early recognition of MAS in SJIA.

The role of flexible bronchoscopy in children with Mycoplasma pneumoniae pneumonia

PURPOSE

To explore the effectiveness of flexible bronchoscopy in pediatric Mycoplasma pneumoniae pneumonia (MPP).

METHODS

This retrospective cohort study included children with MPP admitted between 2016 and 2019 in Shanghai. Tracheobronchial manifestations, etiologic findings, therapeutic effect, and health-economic indicators were assessed in bronchoscopy (plus bronchoalveolar lavage (BAL)) and non-bronchoscopy group. We used propensity-score matching and multivariable logistic regression to investigate the effect of bronchoscopy and BAL on disease recovery.

RESULTS

In 900 children with MPP, 24/278 (8.6%) of those who underwent bronchoscopy had sputum plugs. Coinfection rate was four-fold enhanced by BAL (19.6% vs. 4.5%, p < 0.01) in patients with severe MPP (SMPP) and nearly doubled (10.8% vs. 5.9%, p = 0.03) in those without SMPP, compared with no BAL. Total of 224 (24.9%) patients had multilobar consolidation; after BAL, a significantly shorter lesion-resolution duration was observed on imaging (OR: 0.2, 95% CI: 0.0-0.7). However, longer fever duration (OR: 2.8, 95% CI: 1.7-4.8), hospital stay (OR: 3.1, 95% CI: 1.9-5.1), and higher costs were found in the bronchoscopy group than in the non-bronchoscopy group.

CONCLUSIONS

Through BAL, coinfection may explain one-fifth of causes for SMPP. Bronchoscopy with BAL may increase the detection rate of pathogen and resolve pulmonary lesions in patients with multilobar consolidation.

IMPACT

Flexible bronchoscopy with bronchoalveolar lavage is of great assistance in the timely detection of coinfection, sputum plug and inflammatory polyps in children with Mycoplasma pneumoniae pneumonia (MPP), and improves the recovery of lung damage in MPP patients with multilobar consolidation. This study provides new insights into the indications of flexible bronchoscopy for the diagnosis and treatment of pediatric patients with MPP.

Systematic review and meta-analysis of the diagnostic value of four biomarkers in detecting neonatal sepsis in low- and middle-income countries

BACKGROUND

Biomarkers may enhance diagnostic capability for common paediatric infections, especially in low- and middle-income countries (LMICs) where standard diagnostic modalities are frequently unavailable, but disease burden is high. A comprehensive understanding of the diagnostic capability of commonly available biomarkers for neonatal sepsis in LMICs is lacking. Our objective was to systematically review evidence on biomarkers to understand their diagnostic performance for neonatal sepsis in LMICs.

METHODS

We conducted a systematic review and meta-analysis of studies published in English, Spanish, French, German, Dutch, and Arabic reporting the diagnostic performance of C reactive protein (CRP), erythrocyte sedimentation rate (ESR), white blood cell count (WBC) and procalcitonin (PCT) for neonatal sepsis. We calculated pooled test characteristics and the area under the curve (AUC) for each biomarker compared with the reference standards blood culture or clinical sepsis defined by each article.

RESULTS

Of 6570 studies related to biomarkers in children, 134 met inclusion criteria and included 23 179 neonates. There were 80 (59.7%) studies conducted in LMICs. CRP of ≥60 mg/L (AUC 0.87, 95% CI 0.76 to 0.91) among 1339 neonates and PCT of ≥0.5 ng/mL (AUC 0.87, 95% CI 0.70 to 0.92) among 617 neonates demonstrated the greatest discriminatory value for the diagnosis of neonatal sepsis using blood culture as the reference standard in LMICs.

CONCLUSIONS

PCT and CRP had good discriminatory value for neonatal sepsis in LMICs. ESR and WBC demonstrated poor discrimination for neonatal sepsis in LMICs. Future studies may incorporate biomarkers into clinical evaluation in LMICs to diagnose neonatal sepsis more accurately.

PROSPERO REGISTRATION NUMBER

CRD42020188680.

Pinocembrin Relieves Mycoplasma pneumoniae Infection‑Induced Pneumonia in Mice Through the Inhibition of Oxidative Stress and Inflammatory Response

Pneumonia is a serious infectious disease with increased morbidity and mortality worldwide. The M. pneumoniae is a major airway pathogen that mainly affects respiratory tract and ultimately leads to the development of pneumonia. The current exploration was aimed to uncover the beneficial properties of pinocembrin against the M. pneumoniae-triggered pneumonia in mice via its anti-inflammatory property. The pneumonia was stimulated to the BALB/c mice via infecting them with M. pneumoniae (100 µl) for 2 days through nasal drops and concomitantly treated with pinocembrin (10 mg/kg) for 3 days. The azithromycin (100 mg/kg) was used as a standard drug. Then the lung weight, nitric oxide, and myeloperoxidase (MPO) activity was assessed. The content of MDA, GSH, and SOD activity was scrutinized using kits. The total cells and DNA amount present in the bronchoalveolar lavage fluid (BALF) was assessed by standard methods. The IL-1, IL-6, IL-8, TNF-α, and TGF contents in the BALF samples and NF-κB level in the lung tissues were assessed using kits. The lung histopathology was assessed microscopically to detect the histological alterations. The 10 mg/kg of pinocembrin treatment substantially decreased the lung weight, nitric oxide (NO) level, and MPO activity. The MDA level was decreased, and GSH content and SOD activity were improved by the pinocembrin treatment. The pinocembrin administered pneumonia animals also demonstrated the decreased total cells, DNA amount, IL-1, IL-6, IL-8, TNF-α, and TGF in the BALF and NF-κB level. The findings of histological studies also witnessed the beneficial role of pinocembrin against M. pneumoniae-infected pneumonia. In conclusion, our findings confirmed that the pinocembrin effectively ameliorated the M. pneumoniae-provoked inflammation and oxidative stress in the pneumonia mice model. Hence, it could be a hopeful therapeutic agent to treat the pneumonia in the future.

Fucoxanthin, a Marine Carotenoid, Suppresses Mycoplasma pneumoniae-Triggered Inflammatory Cytokine Production and Promotes Bacterial Clearance in a Murine Model

Mycoplasma pneumoniae (MP), an atypical bacterium, is a common pathogenetic organism of respiratory infection in children. In the present study, we analyzed the beneficial role of fucoxanthin (Fx), a marine carotenoid, in a murine model of MP. C57BL/6 mice were inoculated once intranasally with 107 CFU of M. pneumoniae, and we found that Fx treatment markedly decreased BAL (quantitative bronchoalveolar lavage) M. pneumoniae concentrations and alleviated airway obstruction in the infected mice. Moreover, the concentrations of proinflammatory cytokines, including IL-6, TNF-α and IL-1β, were significantly decreased by Fx treatment in the BAL samples of infected mice. In vitro study further indicated that Fx treatment markedly suppressed the production of proinflammatory cytokines in mouse peritoneal macrophages after M. pneumoniae infection. In conclusion, this may be the first study to report the protective role of Fx against M. pneumoniae infection, providing a potential therapeutic agent for MP.

Cytokine Expression of Lung Bacterial Infection in Newly Diagnosed Adult Hematological Malignancies

Adult patients with hematological malignancies are frequently accompanied by bacterial infections in the lungs when they are first diagnosed. Sputum culture, procalcitonin (PCT), C-reactive protein (CRP), body temperature, and other routinely used assays are not always reliable. Cytokines are frequently abnormally produced in adult hematological malignancies associated with a lung infection, it is uncertain if cytokines can predict lung bacterial infections in individuals with hematological malignancies. Therefore, we reviewed 541 adult patients newly diagnosed with hematological malignancies, of which 254 patients had lung bacterial infections and 287 patients had no other clearly diagnosed infections. To explore the predictive value of cytokines for pulmonary bacterial infection in adult patients with hematological malignancies. Our results show that IL-4, IL-6, IL-8, IL-10, IL-12P70, IL-1β, IL-2, IFN-γ, TNF-α, TNF-β and IL-17A are in the lungs The expression level of bacterially infected individuals was higher than that of patients without any infections (P<0.05). Furthermore, we found that 88.89% (200/225) of patients with IL-6 ≥34.12 pg/ml had a bacterial infection in their lungs. With the level of IL-8 ≥16.35 pg/ml, 71.67% (210/293) of patients were infected. While 66.10% (193/292) of patients had lung bacterial infections with the level of IL-10 ≥5.62 pg/ml. When IL-6, IL-8, and IL-10 were both greater than or equal to their Cutoff-value, 98.52% (133/135) of patients had lung bacterial infection. Significantly better than PCT ≥0.11 ng/ml [63.83% (150/235)], body temperature ≥38.5°C [71.24% (62/87)], CRP ≥9.3 mg/L [53.59% (112/209)] the proportion of lung infection. In general. IL-6, IL-8 and IL-10 are abnormally elevated in patients with lung bacterial infections in adult hematological malignancies. Then, the abnormal increase of IL-6, IL-8 and IL-10 should pay close attention to the possible lung bacterial infection in patients.

Immunological Features of Pediatric Interstitial Pneumonia Due to Mycoplasma pneumoniae

Background: Inflammatory response, oxidative stress, and immunologic mechanism are involved in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). However, the role of immune system of pediatric interstitial pneumonia due to M. pneumoniae infections remains poorly understood. The aim of this study was to analyze the immunologic features of pediatric interstitial pneumonia due to Mycoplasma pneumoniae (M. pneumoniae). Methods: A retrospective study was conducted on a primary cohort of children with MPP. Propensity score analysis was performed to match interstitial pneumonia and pulmonary consolidation children. Results: The clinical characteristics strongly associated with the development of interstitial pneumonia were boys, age >5 years, wheezing history, hydrothorax free, lymphocytes (>3.0 × 10⁹/L), CD19⁺ (>0.9 × 10⁹/L), CD3⁺ (>2.5 × 10⁹/L), CD4⁺ (>1.5 × 10⁹/L), CD8⁺ (>0.9 × 10⁹/L), interleukin-6 (IL-6, <30 pg/ml), IL-10 (<6 pg/ml), and interferon-γ (IFN-γ, <15 pg/ml). After propensity score analysis, children with interstitial pneumonia showed significantly higher CD19⁺, CD3⁺, and CD4⁺ T cell counts, and lower serum IL-6, IL-10, and IFN-γ levels. The final regression model showed that only CD4⁺ T cells (>1.5 × 10⁹/L, OR = 2.473), IFN-γ (<15 pg/ml, OR = 2.250), and hydrothorax free (OR = 14.454) were correlated with the development of interstitial pneumonia among children with MPP. Conclusions: The M. pneumoniae-induced interstitial pneumonia showed increased CD4⁺ T cells and lower serum IFN-γ level. Specific immunologic profiles could be involved in the development of pediatric interstitial pneumonia due to M. pneumoniae infections.

Serum Cytokines and FeNO in School-Aged Children with Mycoplasma pneumoniae Pneumonia

Background

Mycoplasma pneumoniae is a major cause of community-acquired pneumonia (CAP) that is particularly prevalent in school-aged children. This study explored the potential involvement of cytokines in children with Mycoplasma pneumoniae pneumonia (MPP) infection.

Material/Methods

Children aged 3–7 years who were hospitalized due to CAP infection were enrolled and divided into 2 groups: an MPP group (n=33) and a NMPP group (n=38), along with 21 age-matched healthy controls. Clinical characteristics and laboratory data were recorded. Serum levels of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were assessed using Luminex xMAP technology. Correlation analysis and ROC curves analysis were also performed to further explore the role of these detected cytokines in CAP.

Results

Compared with the healthy controls, the serum expression of IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 were significantly higher in the MPP and NMPP groups. Furthermore, serum IL-18 expression was found to be significantly correlated with lgE, FeNO, IL-5, IL-8, and IL-13 concentrations. Significant differences were also observed between the MPP group and NMPP group patients in levels of IL-18, IL-5, and IL-6, and further ROC analysis showed that the area under the curve (AUC) of IL-18 and IL-5 were 0.813 (95% CI: 0.710–0.917; P<0.01) and 0.844 (95% CI: 0.756–0.933; P<0.01), respectively.

Conclusions

IL-18, IL-33, IFN-γ, IL-5, IL-6, IL-8, and IL-13 serum levels showed significant differences in children with CAP. IL-18 and IL-5 were much higher in the MPP group compared to the NMPP group patients, whereas IL-6 levels were significantly lower in these 2 groups.

Nomogram for Prediction of Bronchial Mucus Plugs in Children with Mycoplasma pneumoniae Pneumonia

The presence of bronchial mucus plugs (BMP) in children with Mycoplasma pneumoniae pneumonia (MPP) results in delayed clinical and radiographic resolution and long-standing pulmonary sequelae. The predictive factors associated with BMP formation remains poorly defined. Nomograms to predict BMP presence in children with MPP were proposed using a cohort of patients who underwent bronchoscopy intervention at Children’s Hospital in Eastern China. Patients with MPP in an earlier period formed the training cohort (n = 872) for nomogram development, and those thereafter formed the validation cohort (n = 399) to confirmed model’s performance. BMP in children with MPP were found in 196 (22.5%) and 91(22.8%) patients in the training and validation cohorts, respectively. The independent risk factors associated with BMP were age >5years (OR 2.06; 95% CI 1.43 to 2.98), higher IL-10 level (>10 ng/L, 2.19; 95% CI 1.46 to 3.28), higher IFN-γ level (>30 ng/L, 1.69; 95% CI 1.13 to 2.54), and presence of complication (3.43; 95% CI 1.45 to 8.09). Incorporating these 4 factors, the nomogram achieved good concordance indexes of 0.771(95% CI, 0.734–0.808) and 0.796 (95% CI, 0.744–0.848) in predicting BMP in the training and validation cohorts, respectively. The nomogram achieved an optimal prediction of BMP in children with MPP. Using this model, the risk of BMP formation would be determined, contributing to a rational therapeutic choice.

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

BACKGROUND

There is increasing evidence for a role of lung microbiota in the pathogenesis of Mycoplasma pneumoniae pneumonia (MPP). However, the alterations of lung microbiota in MPP with bronchial mucus plugs and its role in disease pathogenesis remain poorly understood.

METHODS

In this prospective observational study, we performed a longitudinal 16S rRNA-based microbiome survey on bronchoalveolar lavage (BAL) samples collected from 31 MPP with bronchial mucus plugs and 52 MPP without mucus plugs.

RESULTS

Our study showed a clear difference in airway microbiota between MPP children with and without bronchial mucus plugs. The MPP children with mucus plugs had lower abundances of Sphingomonas and Elizabethkingia, and a high abundance of Mycoplasma compared with MPP children without mucus plugs, subsequently contributing to increased ratios of Mycoplasma to Sphingomonas and Mycoplasma to Elizabethkingia. Children's age, fever time and serum cytokine levels were associated with airway microbiota alteration. Furthermore, significant correlations between bacterial genus abundances were found in MPP children with mucus plugs.

CONCLUSIONS

Our results suggest an impact of airway microbiota on the clinical course of MPP in children, deserving further investigations.

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.

Systemic interleukins levels in community-acquired pneumonia and their association with adverse outcomes

Introduction: Community-acquired pneumonia (CAP) is still one of the major causes of morbidity and mortality worldwide. Pro-inflammatory and anti-inflammatory interleukins have been studied to elucidate the role that inflammation plays in its pathogenesis. The aim of this study is to investigate inflammation in CAP, by analyzing in dynamic, serum levels of six interleukins (IL) and their predictive value regarding adverse outcomes.

Materials and methods: Forty adult patients with CAP, admitted in the Teaching Hospital of Infectious Diseases, Cluj-Napoca, Romania from December 2015 to February 2017, were enrolled in this study. Serum levels of pro-inflammatory: IL1β, TNF-α, IL-6, anti-inflammatory: IL-10 and IL-4, along with IL-17A were analyzed in dynamic, on day 1 and day 4.The receiver – operator curves (ROC) were used to analyze the outcome prediction of IL.

Results: Serum levels of IL-1β, IL-6, TNF-α and IL-10 have decreased significantly in dynamic, while IL-4 increases. IL-17A has acted like a pro-inflammatory cytokine. We have found a correlation between IL-6 and IL-10 (r=0.429, p=0.000), IL-6 and IL-17A (r=0.295, p=0.008) and IL-10 and IL-17A (r=0.475, p=0.000). Out of 40 patients, 9 had adverse outcomes, consisting in 9 relapses from which 1 died. IL-6 discriminates alone between adverse and favorable outcomes. With multivariate analysis and multiple regression of all combined IL, we have found that there is a predictive model regarding adverse outcomes.

Conclusion: IL-10 and IL-17A behave like pro-inflammatory cytokines. IL-6 is a predictive marker for adverse outcomes alone. All IL studied together have an impact on adverse outcomes.

Ameliorative Effects of Infantile Feire Kechuan Oral Solution on Mycoplasma Pneumoniae Pneumonia in Infant Mouse and Rat Models

Mycoplasma pneumoniae (MP) infection is a major pathogen of community-acquired pneumonia (CAP) in children worldwide. Infantile Feire Kechuan Oral Solution (IFKOS) has been used for the treatment of MP pneumonia clinically in China for many years. The present study was designed to investigate the therapeutic effect of IFKOS on MP pneumonia and explore the potential mechanism of the actions. The infant BALB/c mouse and Wistar rat models of MP infection were successfully established to confirm the therapeutic effects of IFKOS, followed by assays for related cytokines and investigations of the IgM response involved. The results showed that IFKOS exhibited an inhibitory effect on pulmonary index (PI) and effectively reduced the degree of lesions in the lungs. The lethal rate of mice was significantly decreased while survival time of mice was dramatically increased by IFKOS treatment in comparison to infection control, respectively. IFKOS treatment (40, 20, and 10ml/kg) significantly decreased the level of MP-IgM in a dose-dependent manner, whereas IFKOS showed no obvious inhibitory effect on the increase of relative expression of MP-DNA. In addition, the elevated IL-2 and TNF-α levels were significantly reduced and the decreased IL-6 level was significantly enhanced by IFKOS treatment. Our study demonstrates that IFKOS has inhibitory effect on MP infection in infant mouse and rat models of MP pneumonia and protective effect from lethal MP challenge in infant murine model. These anti-MP effects might be related to suppression of the IgM response and a reversal the imbalance of Th1/Th2 cytokines induced by MP infection.

Low birth weight contributed to increased serum IL-6 levels in infantile respiratory syncytial virus infection

Background

To evaluate the role of serum cytokines in the pathogenesis of respiratory syncytial virus (RSV) infection in infants with low birth weight (LBW).

Methods

A prospective observational study was performed, and hospitalized children with lower respiratory tract infection (LRTI) were recruited. Three hundred fifty-eight patients < 1 year met the inclusion criteria: 116 patients had only RSV infection (RSV group); 242 patients had no RSV or other specific pathogen (non-RSV group). Serum interleukin-2 (IL-2), IL-4, IL-6, IL-10, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were detected through flow cytometry.

Results

No significant differences in serum IL-2, 4, 6, 10, and IFN-γ levels were observed between the RSV and non-RSV groups. For RSV infected infants with or without wheezing, delivery mode had no obvious effect on the changes of serum cytokine levels. However, the level of IL-6 in the RSV-infected infants with LBW was significantly higher than that in infants with normal birth weight.

Conclusions

Serum IL-6 level was significantly increased in RSV infected infants with LBW. It is likely that the specific serum cytokine pattern will contribute to our understanding of the pathogenesis of RSV infections, especially in RSV-infected infants with LBW.

TIPE2 negatively regulates mycoplasma pneumonia-triggered immune response via MAPK signaling pathway

Excessive immune responses played an important role in pathophysiology of mycoplasma pneumonia (MP) infection. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) is a negative regulator of immune response. This study investigated the expression change of TIPE2 and its role in immune defense against MP infection, as well as the underlying mechanisms. Expressions of TIPE2 both in patients and in macrophages in vitro after MP infection were measured. We further studied cytokine production and mitogen-activated protein kinase (MAPK) signaling function in macrophages with interfered expression of TIPE2 upon MP infection. A significant decrease of TIPE2 mRNA expression was observed in peripheral blood mononuclear cells (PBMCs) from MP patients, which was correlated with the severity of infection. Accordingly we found down-regulation of TIPE2 expression in macrophages after MP infection. In vitro study further suggested that TIPE2 jeopardized inflammatory cytokine production trigged by MP infection via inhibiting MAPK signaling pathway. These findings provided evidences of the novel function of TIPE2 in anti-MP immunity and its possible clinical utility related clinical significance.