Mycoplasma pneumoniae induces allergy by producing P1-specific immunoglobulin E

The impact of atopy on the clinical characteristics of mycoplasma pneumoniae pneumonia in pediatric patients

Mycoplasma pneumoniae (MP) is one of the pathogens that cause community-acquired pneumonia in children. Atopic diseases are also common in children. However, the impact of atopy on Mycoplasma pneumoniae pneumonia (MPP) in children is still unclear. The purpose of this study is to analyze the impact of atopy on the clinical characteristics of MPP in children, and provide a diagnosis and treatment plan. A total of 489 children hospitalized for MPP in our hospital from June 2023 to December 2023 were selected. They were divided into an atopic group (n = 172) and a non-atopic group (n = 317) based on whether they had atopy or not. Clinical data, treatment regimens, and laboratory indicators were compared between the two groups. Eosinophil count, lactate dehydrogenase and IgE levels were higher in the atopic group than in the non-atopic group. Additionally, neutrophil percentage, procalcitonin levels were lower in the atopic group than in the non-atopic group (P < 0.05). The proportion of bronchiolitis type on lung imaging was higher in the atopic group, and there was a higher incidence of severe pneumonia compared to the non-atopic group (P < 0.05). Atopy may lead to severe MPP and bronchiolitis-type MPP. Therefore, the treatment and prognosis of these children should be given more attention.

Refractory and Relapsing Laryngeal Edema Possibly Associated With Chronic Tonsillitis and Mycoplasma Infection, Requiring Reintubation and Tracheostomy

Relapsing epiglottitis has rarely been reported, and its etiology is not well established. A 44-year-old previously healthy Japanese man presented with a quickly progressing choking sensation. He had been experiencing refractory and relapsing laryngeal edema and probably acute epiglottitis (three episodes within 2 weeks), with rash and elevated pancreatic amylase. The patient required immediate intubation. After the initial extubation, he required reintubation and a subsequent tracheostomy. Antibiotics, glucocorticoid, and antihistamines were administered, and he finally recovered with the tracheostomy's closure. Potential causes of this patient's relapsing epiglottitis are as follows: persistent right swollen tonsil; a positive result on a Mycoplasma pneumoniae antigen test and a particle agglutination (PA) test, implicating chronic tonsillitis; and/or Mycoplasma infection. This is the first case report of refractory and relapsing epiglottitis requiring reintubation possibly concurrent with chronic tonsillitis and Mycoplasma infection.

New Insights on the Clinical Significance of Mycoplasma pneumoniae DNA Load in Mycoplasma pneumoniae Pneumonia

Objective This study aimed to assess the consistency of Mycoplasma pneumoniae (MP)-DNA load in the respiratory tracts, its correlation with Mycoplasma pneumoniae pneumonia (MPP) manifestations, and its predictive value for refractory Mycoplasma pneumoniae pneumonia (RMPP).

Methods A retrospective study was performed on a cohort of MPP cases, including 215 patients with positive nasopharyngeal aspirate (NPA) MP-DNA and 59 with positive bronchoalveolar lavage fluid (BALF) MP-DNA. Patients were categorized into two groups based on MP-DNA load: low load (≤106/mL) and high load (>106/mL). The consistency of MP-DNA load in NPA and BALF was determined by Spearman's correlation coefficient. Clinical, laboratory, and radiological data were compared, and the predictive value of NPA MP-DNA for RMPP was evaluated using the receiver operating characteristic curve.

Results A strong correlation was observed between NPA and BALF MP-DNA. High-load groups in both had longer fever durations and more pronounced increases in C-reactive protein, lactate dehydrogenase, and ferritin (p < 0.05). Routine-dose glucocorticoids were more required for patients exhibiting high MP-DNA loads, regardless of the source of the sample. The area under the curve for predicting RMPP using NPA MP-DNA load was 0.861, with 92.9% sensitivity and 67.9% specificity at a cutoff of 9.5 × 105/mL.

Conclusion The NPA MP-DNA load reflects the severity of pulmonary inflammatory response. Increased MP-DNA load in both the upper and lower airways is associated with longer fever and increased inflammation, indicating a need for glucocorticoid therapy. NPA MP-DNA can predict RMPP with high sensitivity.

Exploring the pathogenetic mechanisms of Mycoplasmapneumoniae (Review)

Mycoplasmas, the smallest self-replicating prokaryotes without a cell wall, are the most prevalent and extensively studied species in humans. They significantly contribute to chronic respiratory tract illnesses and pneumonia, with children and adolescents being particularly vulnerable. Mycoplasma pneumoniae (M. pneumoniae) infections typically tend to be self-limiting and mild but can progress to severe or even life-threatening conditions in certain individuals. Extrapulmonary effects often occur without pneumonia, and both intrapulmonary and extrapulmonary complications operate through separate pathological mechanisms. The indirect immune-mediated damage of the immune system, vascular blockages brought on by vasculitis or thrombosis and direct harm from invasion or locally induced inflammatory cytokines are potential causes of extrapulmonary manifestations due to M. pneumoniae. Proteins associated with adhesion serve as the primary factor crucial for the pathogenicity of M. pneumoniae, relying on a specialized polarized terminal attachment organelle. The type and density of these host receptors significantly impact the adhesion and movement of M. pneumoniae, subsequently influencing the pathogenic mechanism and infection outcomes. Adjacent proteins are crucial for the proper assembly of the attachment organelle, with variations in the genetic domains of P1, P40 and P90 surfaces contributing to the variability of clinical symptoms and offering new avenues for developing vaccines against M. pneumoniae infections. M. pneumoniae causes oxidative stress within respiratory tract epithelial cells by adhering to host cells and releasing hydrogen peroxide and superoxide radicals. This oxidative stress enhances the vulnerability of host cells to harm induced by oxygen molecules. The lack of superoxide dismutase and catalase of bacteria allows it to hinder the catalase activity of the host cell, leading to the reduced breakdown of peroxides. Lung macrophages play a significant role in managing M. pneumoniae infection, identifying it via Toll-like receptor 2 and initiating the myeloid differentiation primary response gene 88-nuclear factor κΒ signaling cascade. However, the precise mechanisms enabling M. pneumoniae to evade intracellular host defenses remain unknown, necessitating further exploration of the pathways involved in intracellular survival. The present comprehensive review delves into the pathogenesis of M. pneumoniae infection within the pulmonary system and into extrapulmonary areas, outlining its impact.

The molecular characteristics, diagnosis, and treatment of macrolide-resistant Mycoplasma pneumoniae in children

The purpose of this study is to review the molecular characteristics, the diagnosis, and treatment of the widespread infection of macrolide-resistant Mycoplasma pneumoniae (M. pneumoniae; MRMP) in children, thus providing a better knowledge of this infection and presenting the associated problems. Single point mutations in the V region of the 23S rRNA gene of M. pneumoniae genome are associated with macrolide resistance. P1-1, MLVA4-5-7-2, and ST3 are usually the predominated genetic types in the M. pneumoniae epidemics. The short-term two times serological IgM (or together with IgG) test in the acute stage can be used for confirmation. Combined serological testing and PCR might be a more prudent method to reduce macrolide consumption and antibiotic selective pressure in a clinical setting. Molecular methods for the detection of single-nucleotide mutations in the V region of the 23S rRNA gene can be used for the diagnosis of MRMP. The routine use of macrolide for the treatment of macrolide-sensitive Mycoplasma pneumoniae (MSMP) infections can get good effect, but the effects are limited for severe MRMP infections. Additional corticosteroids may be required for the treatment of severe MRMP infections in children in China during the era of MRMP.

Reserve of Wnt/β-catenin Signaling Alleviates Mycoplasma pneumoniae P1-C-induced Inflammation in airway epithelial cells and lungs of mice

Mycoplasma pneumoniae (M. pneumoniae) is the most common pathogen of respiratory tract infections in both children and adults. M. pneumoniae P1 adhesin plays an important role in the pathogenesis of M. pneumoniae infection by mediating the attachment of pathogen to host cells. The inoculation of C-terminal residuals of P1 (P1-C) showed a protective role from M. pneumoniae infection. Accumulated evidence suggests that the Wnt/β-Catenin signaling is implicated in regulation of inflammatory responses to bacterial infections. However, mechanisms underlying the regulatory roles of Wnt signaling in host cells in response to M. pneumoniae infections are incompletely understood. In the present study, the impact and molecular mechanism of Wnt/β-catenin signaling in immune responses induced by M. pneumoniae P1-C were investigated. The results demonstrated that the P1-C could activate Wnt/β-catenin and Toll-like receptor (TLR) signaling in primary mouse airway epithelial cells cultured in an air-liquid interface (ALI) state. Interestingly, the inhibition of Wnt/β-catenin signaling by an adenovirus-mediated Wnt inhibitor Dickkopf-1 (Dkk1) gene transduction alleviated the P1-C induced inflammation fibrosis in mouse lung, accompanied by the reduced expression of epithelial mesenchymal transition (EMT) markers. Mechanistical analysis further demonstrated that the Dkk1 could suppress the expression of JAK2/STAT1-STAT3 and Caspase3, 8/Bax signaling in mouse lung tissues. In vitro study further revealed that XAV939, a small molecule of Wnt/β-catenin inhibitor, inhibited the P1-C-activated TLR4/MyD88 signaling and cytokine productions in primary mouse airway ALI epithelial cells. This study thus provides an insight into the function of Wnt/β-catenin signaling in regulation of the pathogenesis of M. pneumoniae infection, suggesting that targeting Wnt/β-catenin signaling by gene transduction of Dkk1, or pharmacological molecules of inhibitor may be a promised approach that worthy of further investigation in the treatment of M. pneumoniae pneumonia.

Insight into the Pathogenic Mechanism of Mycoplasma pneumoniae

Mycoplasma pneumoniae, an obligate parasitic pathogen without cell wall, can cause severe upper and lower respiratory tract symptoms. It is the pathogen of human bronchitis and walking pneumonia, and named community-acquired pneumonia. In addition to severe respiratory symptoms, there are clinical extrapulmonary manifestations in the skin, brain, kidney, musculoskeletal, digestive system, and even blood system after M. pneumoniae infection. Hereby, we comprehensively summarized and reviewed the intrapulmonary and extrapulmonary pathogenesis of M. pneumoniae infection. The pathogenesis of related respiratory symptoms caused by M. pneumoniae is mainly adhesion damage, direct damage including nutrient predation, invasion and toxin, cytokine induced inflammation damage and immune evasion effect. The pathogenesis of extrapulmonary manifestations includes direct damage mediated by invasion and inflammatory factors, indirect damage caused by host immune response, and vascular occlusion. The intrapulmonary and extrapulmonary pathogenic mechanisms of M. pneumoniae infection are independent and interrelated, and have certain commonalities. In fact, the pathogenic mechanisms of M. pneumoniae are complicated, and the specific content is still not completely clear, further researches are necessary for determining the detailed pathogenesis of M. pneumoniae. This review can provide certain guidance for the effective prevention and treatment of M. pneumoniae infection.

Serum cytokine profiling reveals different immune response patterns during general and severe Mycoplasma pneumoniae pneumonia

Mycoplasma pneumoniae (MP) is an important human pathogen that mainly affects children causing general and severe Mycoplasma pneumoniae pneumonia (G/SMPP). In the present study, a comprehensive immune response data (33 cytokines) was obtained in school-age children (3-9 years old) during MPP, aiming to analyze the immune response patterns during MPP. At acute phase, changes of cytokines were both detected in GMPP (24/33) and SMPP (23/33) groups compared to the healthy group (p < 0.05), with 20 identical cytokines. Between MPP groups, the levels of 13 cytokines (IL-2, IL-10, IL-11, IL-12, IL-20, IL-28A, IL-32, IL-35, IFN-α2, IFN-γ, IFN-β, BAFF, and TSLP) were higher and three cytokines (LIGHT, OPN and CHI3L1) were lower in the SMPP group than in the GMPP group (p < 0.05). Function analysis reveals that macrophage function (sCD163, CHI3L1) are not activated in both MPP groups; difference in regulatory patterns of T cells (IL26, IL27, OPN, LIGHT) and defective activation of B cells (BAFF) were detected in the SMPP group compared to the GMPP group. Besides, the level of osteocalcin; sIL-6Rβ and MMP-2 are both decreased in MPP groups at acute and convalescent phases compared to the healthy group, among which the levels of sIL-6Rβ and MMP-2 showed negative correlations (p < 0.1) to the application of bronchial lavage in SMPP group, indicating their roles in the development of MPP. At the convalescent phase, more cytokines recovered in GMPP (18) than SMPP (11), revealing better controlled immune response during GMPP. These results reveal different immune response patterns during GMPP and SMPP. In addition, the differentiated cytokines may serve as potential indicators of SMPP; early intervention on immune response regulations may be helpful in reducing the severity of SMPP.

Mycoplasma pneumonia Infection Is Associated With an Increased Risk of Systemic Lupus Erythematosus: A Nationwide, Retrospective Cohort Study

Background

Infections may play a role in the development of systemic lupus erythematosus (SLE).

Objective

To assess the link between Mycoplasma pneumonia (M. pneumonia) infection and the incidence of SLE.

Method

We conducted a retrospective cohort study, which identified 116,043 hospitalized patients with M. pneumoniae between 2000 and 2012 from the Taiwan National Health Insurance Research Database and compared them with 447,839 matched inpatients who had never been diagnosed with M. pneumonia infection (at a 1:4 ratio, matched by age, gender, and index year). Their comparative risk of developing SLE was evaluated. The follow-up period was defined as the time from the initial diagnosis of M. pneumonia infection to the date of SLE diagnosis, or December 31, 2013. The incidence rates of SLE were assessed in people with and without M. pneumoniae infection. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), with the uninfected group used as the reference.

Results

The adjusted HR of SLE for the M. pneumoniae group was 2.97 with 95% CI = 2.18–4.05 compared with the uninfected group. The risk was most significantly higher within 0.5 years after the M. pneumoniae infection with an adjusted HR of 6.18 (95% CI = 3.82–9.97, p < 0.01). The adjusted HR for SLE from 0.5 to 2 years and from 2 to 5 years after M. pneumoniae infection was 1.59 (95% CI = 0.70–3.59, p = 0.27) and 2.42 (95% CI = 1.22–4.81, p = 0.01), respectively.

Conclusion

The incidence of SLE was significantly higher in subjects infected with M. pneumoniae.

Immune responses to bacterial lung infections and their implications for vaccination

The pulmonary immune system plays a vital role in protecting the delicate structures of gaseous exchange against invasion from bacterial pathogens. With antimicrobial resistance becoming an increasing concern, finding novel strategies to develop vaccines against bacterial lung diseases remains a top priority. In order to do so, a continued expansion of our understanding of the pulmonary immune response is warranted. Whilst some aspects are well characterised, emerging paradigms such as the importance of innate cells and inducible immune structures in mediating protection provide avenues of potential to rethink our approach to vaccine development. In this review, we aim to provide a broad overview of both the innate and adaptive immune mechanisms in place to protect the pulmonary tissue from invading bacterial organisms. We use specific examples from several infection models and human studies to depict the varying functions of the pulmonary immune system that may be manipulated in future vaccine development. Particular emphasis has been placed on emerging themes that are less reviewed and underappreciated in vaccine development studies.

Increased Total Serum Immunoglobulin E Is Likely to Cause Complications of Mycoplasma pneumoniae Pneumonia in Children

Objective

To investigate the correlation between serum immunoglobulin E (IgE) levels and the complications in children with Mycoplasma pneumoniae pneumonia (MPP).

Methods

A retrospective study of MPP patients hospitalized from May 2019 to July 2021 was performed. We analyzed the clinical manifestations, complications, laboratory findings, and treatments.

Results

A total of 275 patients who met the inclusion criteria were enrolled in the study. We divided patients into two groups based on whether there were complications. Complications occurred in 147 patients, of which pulmonary complications were more common than extrapulmonary complications. The IgE level in the complication group was higher than that in the non-complication group with p = 0.041. Patients with complications of necrotizing pneumonitis, pneumothorax, skin rash, or bronchiolitis obliterans had higher IgE levels. There was no statistically significant difference in IgE levels between pulmonary complications and extrapulmonary complications. The older the age, the greater the probability of complications (p = 0.001). The group with complications was more likely to have chest pain (p = 0.000), while the group without complications was more likely to have wheezing (p = 0.017). The use of bronchoscopy and glucocorticoids was higher in the complication group than in the non-complication group (p = 0.000).

Conclusions

MPP patients with higher IgE levels had more severe clinical symptoms and complications. We speculated that IgE might be a biomarker for complications after MP infection.

Mycoplasma pneumoniae infection and risk of childhood asthma: A systematic review and meta-analysis

The etiology of childhood asthma is multifactorial, atypical bacterial pathogens, including Mycoplasma pneumoniae, have been proposed as possible risk factors or contributors. This review aims to assess the possible association between M. pneumoniae infection and childhood asthma. We searched major international literature databases (up to January 10, 2021) to identify relevant studies. We used a random-effects meta-analysis (REM) model to generate the pooled odds ratio (OR) and 95% confidence intervals (CIs). Several subgroups analyses were performed concerning the IgG, IgM, and DNA detection of M. pneumoniae infection. We included 22 eligible studies; these studies involved a total of 5064 children. We found that there was a statistically significant association between M. pneumoniae infection, as determined by IgM serology (OR, 3.13; 95% CI, 1.78-5.48), and DNA detection (OR, 1.57; 95% CI, 1.25-1.97) with increased risk of any type of childhood asthma. Moreover, children with acute asthma had significantly higher seropositivity for anti- M. pneumoniae IgM antibodies (OR, 4.43; 95% CI, 2.80-7.02) than children with stable asthma. Although our findings indicate a positive association between M. pneumoniae infection and childhood asthma, well-designed and -controlled studies are need in the future to rigorously test this association and identify the underlying mechanisms.

Analysis of Clinical Characteristics and Risk Factors of Severe Adenovirus Pneumonia in Children

Objective: To analyze the clinical characteristics of adenovirus pneumonia (ADVP) in children and explore risk factors for severe ADVP. Methods: Clinical data from 7,008 hospitalized children with community-acquired pneumonia and 211 with ADVP were retrospectively analyzed between July 2014 and June 2019. Eighty-six patients were diagnosed with severe pneumonia, and related risk factors were analyzed. Results: ADVP accounts for 3.01% (211/7008) of CAP in hospitalized children. Among 211 patients, 167 (64.9%) children aged 1-5 years old, and the onset was in winter and spring for 126 (59.7%) children. All patients had cough, and 116 (92.8%) patients with mild cases and 82 (95.4%) patients with severe cases had varying degrees of fever. The duration of fever in the severe ADVP group and mild ADVP group was 7.3 and 5.4 days, respectively. The average hospital stays were 9.8 and 5.8 days, respectively. There was no significant difference in the levels of WBC and ESR between the two groups, but the levels of N%, CRP, PCT and LDH in children with severe ADVP were significantly higher than those in the mild ADVP group. The univariate analysis showed that there were significant differences between the severe ADVP group and the mild ADVP group in ≥7 days of fever and high IgE (P < 0.05). There was no significant difference in sex, age, onset season, mycoplasma infection, bacterial infection between the two groups (P > 0.05). The multivariate logistic analysis showed that ≥7 days of fever and high IgE were independent risk factors for severe ADVP (P < 0.05). Conclusions: Children with severe ADVP have long fever duration, a strong inflammatory response and immune function disturbance. Fever duration (≥7 days) and high IgE were independent risk factors for severe ADVP.

Mycoplasma pneumoniae: Atypical Pathogen in Community Acquired Pneumonia

Mycoplasma pneumoniae is a one of most common reasons of respiratory tract infections in both adolescents and children with severity ranged from moderate to high. Many facts in the previous years regarding infections were induced via this organism having extra pathogenic mechanisms. Clinically, resistance to macrolide has produced internationally and represents a treatment trouble. Antimicrobial sensitivity checking out techniques have been applied, and novel antibiotics which are effective towards M. pneumoniae are present processing development. That evaluate concentrates on the several trends occurring in the previous quite a few years which beautify the grasp of that microorganism, which is one of the smallest pathogenic bacteria; however, is of extreme medical significance.

Bacteria in Asthma Pathogenesis

The airways are under continuous assault from aerosolized bacteria and oral flora. The bacteria present in the airways and gastrointestinal tract of neonates promote immune maturation and protect against asthma pathogenesis. Later bacterial infections and perturbations to the microbiome can contribute to asthma pathogenesis, persistence, and severity.

Impact of atopy on the severity and extrapulmonary manifestations of childhood Mycoplasma pneumoniae pneumonia

Objectives

The impact of atopy on disease severity and extrapulmonary manifestations in children with Mycoplasmapneumoniae (MP) pneumonia is unknown.

Methods

Patients diagnosed with MP pneumonia between January 2016, and December 2017, were enrolled in this study. A total of 150 MP pneumonia patients were enrolled at diagnosis and divided into the atopic group (n = 48) and the nonatopic group (n = 102). Furthermore, these patients were also assessed after being divided into the pulmonary group (n = 120) and the extrapulmonary group (n = 30). Clinical characteristics, respiratory disease severity, any allergy history, and specific allergen sensitizations were collected from all patients. The serum interleukin‐17 (IL‐17) and total immunoglobulin E (lgE) levels were also measured.

Results

More children in the atopic group than those in the nonatopic group presented with severe MP pneumonia, tachypnea, oxygen therapy, steroid treatment, atopic conditions including asthma attack, a previous history of asthma, decreased IL‐17 levels, and increased IgE levels (all P < 0.05). When compared with those in the pulmonary group, the patients in the extrapulmonary group showed higher percentages of atopy, higher total lgE levels, and lower IL‐17 levels (all P < 0.05).

Conclusions

Atopy may be a risk factor for disease severity and extrapulmonary manifestations in children with MP pneumonia.