Thrombosis associated with mycoplasma pneumoniae infection (Review)

Development and Evaluation of a Nomogram for Predicting Pulmonary Embolism in Children With Severe Mycoplasma pneumoniae Pneumonia

OBJECTIVE

To construct a nomogram utilizing pediatric severe Mycoplasma pneumoniae pneumonia (SMPP) risk factors for pulmonary embolism (PE), facilitating the clinical identification and management of high-risk patients and reducing the excessive use of CT pulmonary angiography (CTPA).

METHOD

This was a retrospective analysis conducted between August 2021 and March 2024. We identified 35 children with SMPP complicated by PE, forming the PE group. A control group of 70 age- and sex-matched children with SMPP without PE was randomly selected at a 1:2 ratio. Clinical, laboratory, and CT findings were compared between the groups. Least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression were used to develop a scoring model using a nomogram. The model's performance was assessed via the receiver operating characteristic curve (ROC), fivefold cross-validation, calibration curve, and clinical decision curve analysis.

RESULTS

LASSO regression and multivariate logistic regression analyses revealed that D-dimer, neutrophil ratio, time to admission, pleural effusion, and necrotizing pneumonia were independent risk factors for PE in patients with SMPP. A nomogram prediction model was established based on the aforementioned independent risk factors. The area under ROC curve was 0.900. Fivefold cross-validation results further confirmed the model's stability. The calibration curve revealed good agreement between the predicted and actual probabilities of PE caused by SMPP, and the decision curve demonstrated that the nomogram model had a higher clinical net benefit.

CONCLUSIONS

The nomogram serves as a predictive tool to aid in early intervention for pediatric patients with SMPP at high risk for PE, while minimizing unnecessary CTPA and overtreatment in low-risk patients.

Pulmonary embolism in children with mycoplasma pneumonia: can it be predicted?

PURPOSE

To investigate the clinical characteristics of Mycoplasma pneumoniae (MP) pneumonia (MPP) combined with pulmonary embolism (PE) in children.

METHODS

291 hospitalized pediatric cases with MPP were enrolled from January 2018 to May 2024 and divided into the PE group (141 cases) and non-PE control group (150 cases). Clinical data of both groups were analyzed and compared.

RESULTS

C-reactive protein (CRP), D-dimer, lactate dehydrogenase (LDH), and interleukin 6 (IL-6) were significantly higher in the PE group than in the non-PE control group. There were 85 males and 56 females in the PE group. The PE group has male-to-female ratio of 3: 2,and hemoptysis was observed in 11 children (7.08%), chest pain in 29 children (20.60%), and pulmonary necrosis in 89 children (63.12%). In the receiver operator curve(ROC), the areas under the curve(AUC) for D-dimer, CRP, IL-6, and LDH were 0.964, 0.690, 0.632, and 0.765, respectively. In the ROC curve, the cutoff values for D-dimer, CRP, IL-6, and LDH were 0.8 µg/ml, 24.2 mg/L, 37.8 pg/ml, and 461 U/L, respectively.

CONCLUSION

A proportion of children with MP infection combined with PE show atypical clinical symptoms. Children with MPP and elevated D-dimer levels, IL-6, CRP, erythrocyte sedimentation rate (ESR), and LDH may be prone to develop PE.

Gut microbiota and myocardial infarction: A bibliometric analysis from 2004 to 2023

Background

In recent years, numerous studies have suggested that the gut microbiota and its metabolites are closely related to myocardial infarction. Utilizing insights from these research findings may be advantageous in the prevention, treatment, and prognosis of myocardial infarction. We have employed bibliometric methodology to summarize the progress made in this research area over the past 20 years, identify the hotspots, and highlight the developmental tendencies, providing a reference for future research in this field.

Methods

We searched the content related to this field in the Web of Science Core Collection database, with a time range from 2001 to 2023. We used VOSviewer, CiteSpace, and Scimago Graphica software to visualize the search results.

Results

We included 889 reports in this study. The country with the most publications was China, while the country with the greatest influence was the United States. An analysis of institutions showed that the Chinese Academy of Medical Sciences had the largest volume of publications, whereas the Cleveland Clinic had the most influential ones. An author analysis showed Stanley L Hazen to have published the most and to also have been the most influential researcher. An analysis of all the journals publishing articles related to the search terms showed that PLoS One journal had the highest number of publications (18 articles), while Atherosclerosis journal had the most influential articles. The results of our reference analysis showed a strong association between Trimethylamine N-oxide and myocardial infarction. We found that increased intestinal permeability may be related to the progression of cardiovascular diseases, a high-fiber diet may help in the prevention of diseases such as myocardial infarction, and populations with a high intake of red meat may have an increased risk of myocardial infarction. Keyword analysis suggested that 'cardiac fibrosis' and 'major bleeding' were promising research directions in the future, and supplementing food intake with short-chain fatty acids was looked upon as a promising approach to treating coronary heart disease.

Conclusion

The gut microbiota are closely related to myocardial infarction, and investigating this relationship is crucial for the prevention and treatment of myocardial infarction, where interdisciplinary research and international cooperation are indispensable.

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.

Intracardiac and Cerebral Thrombosis Complicated With Mycoplasma Pneumonia

A seven-year-old girl developed multiposition thrombosis after fever and respiratory symptoms. Chest computed tomography (CT) scan demonstrated bilateral infiltrates, consolidation of the right lower lobe, and pleural effusion in the right lung field. Brain magnetic resonance imaging (MRI) showed multiple abnormal signals in the brain with limited diffusion, and cerebral infarction could not be excluded. Echocardiography revealed hypoechoic mitral valve tips, which are likely to be suspected as vegetation. Mycoplasma pneumoniae infection was clarified by a four-fold increase in IgG antibodies to M. pneumoniae sera. D-dimer levels were elevated increasingly. We found and reported this rare pediatric case of an M. pneumoniae-induced severe pneumonia complicated with intracardiac and cerebral thrombosis. We investigate the clinical characteristics, diagnosis, and treatment of refractory mycoplasma pneumonia complicated with intracardiac and cerebral thrombosis in children.

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.

Diagnostic Challenges in Pulmonary Embolism in Young Adults: Thrombosis Associated With Cytomegalovirus and Mycoplasma pneumoniae

A 23-year-old man presented with a fever, shaking chills, headaches, nausea, and a dry cough. Investigations showed lymphocytic leukocytosis with atypical lymphocytes in a blood smear. Liver function test results, D-dimer concentrations, and fibrin degradation product concentrations were greatly elevated. Computed tomography of the whole body with contrast showed hepatosplenomegaly with splenic infarction and bilateral pulmonary embolism without deep vein thrombosis. Cytomegalovirus (CMV) immunoglobulin M, and serum CMV pp65 antigenemia were positive, and serum Mycoplasma pneumoniae (M. pneumoniae) antibody was also highly positive. These results suggested the diagnosis of co-infection of CMV and M. pneumoniae complicated by systemic arteriovenous thrombosis, which resulted in pulmonary embolism and splenic infarction. After he started edoxaban tosilate hydrate for the thrombosis, his symptoms resolved in a few days. To the best of our knowledge, this is the first case of co-infection of CMV and M. pneumoniae leading to pulmonary embolism and splenic infarction.

Analysis of the risk factors and clinical features of Mycoplasma pneumoniae pneumonia with embolism in children: a retrospective study

Background

Mycoplasmapneumoniae pneumonia (MPP) is a prevalent disease in community-acquired pneumonia among children. However, in addition to respiratory manifestations, it may also develop extra-pulmonary complications. Embolism is one of the uncommon extra-respiratory manifestations prone to severe sequelae and even death. This study aims to analyze the clinical features of MPP with embolism in children, and explore the associated risk factors of embolism in MPP patients.

Methods

A retrospective case–control analysis was performed on 48 children with MPP admitted to our hospital wards between January 2010 and December 2021. Embolism group comprised children with embolism by CTA or MRA results, whereas the non-embolism group comprised children with clinical suspicion of embolism but negative diagnostic imaging support. The clinical features, laboratory findings and imaging were analyzed to explore the risk factors for embolism in children with MPP.

Results

A total of 48 children with MPP were enrolled in the study (16 cases and 32 controls). In the embolism group, 10 patients (62.5%) had pulmonary embolism, 3 patients (18.75%) presented ventricle embolism, 2 patients (12.5%) presented cerebral and carotid artery embolism, one patient (6.25%) had a cerebral embolism, limb, and spleen, respectively. The univariate analysis revealed the maximum body temperature (Tmax), CRP, D-dimer (closest to CTA/MRA), the percentage of neutrophils (N%), pulmonary consolidation (⩾ 2/3 lobe), pleural effusion and atelectasis have significant differences between the embolism group and non-embolism group (P < 0.05). Multivariate logistic regression analysis showed that D-dimer (closest to CTA/MRA) > 3.55 mg/L [OR = 1.255 (95% CI: 1.025—1.537), P < 0.05], pulmonary consolidation (⩾ 2/3 lobe) [OR = 8.050 (95% CI: 1.341—48.327), P < 0.05], and pleural effusion [OR = 25.321 (95% CI: 2.738—234.205), P < 0.01] were independent risk factors for embolism in children with MPP.

Conclusion

In conclusion, MPP with embolism patients have more D-dimer values and severe radiologic manifestations.