Evaluation of variation in coagulation among children with Mycoplasma pneumoniae pneumonia: a case-control study

Development of machine learning-based differential diagnosis model and risk prediction model of organ damage for severe Mycoplasma pneumoniae pneumonia in children

Severe Mycoplasma pneumoniae pneumonia (SMPP) poses significant diagnostic challenges due to its clinical features overlapping with those of other common respiratory diseases. This study aims to develop and validate machine learning (ML) models for the early identification of SMPP and the risk prediction for liver and heart damage in SMPP using accessible laboratory indicators. Cohort 1 was divided into SMPP group and other respiratory diseases group. Cohort 2 was divided into myocardial damage, liver damage, and non-damage groups. The models built using five ML algorithms were compared to screen the best algorithm and model. Receiver Operating Characteristic (ROC) curves, accuracy, sensitivity, and other performance indicators were utilized to evaluate the performance of each model. Feature importance and Shapley Additive Explanation (SHAP) values were introduced to enhance the interpretability of models. Cohort 3 was used for external validation. In Cohort 1, the SMPP differential diagnostic model developed using the LightGBM algorithm achieved the highest performance with AUCROC = 0.975. In Cohort 2, the LightGBM model demonstrated superior performance in distinguishing myocardial damage, liver damage, and non-damage in SMPP patients (accuracy = 0.814). Feature importance and SHAP values indicated that ALT and CK-MB emerged as pivotal contributors significantly influencing Model 2's output magnitude. The diagnostic and predictive abilities of the ML models were validated in Cohort 3, demonstrating the models had some clinical generalizability. The Model 1 and Model 2 constructed by LightGBM algorithm showed excellent ability in differential diagnosis of SMPP and risk prediction of organ damage in children.

Mycoplasma pneumoniae pneumonia in children

Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen that causes community-acquired pneumonia in children. The clinical presentation of this pathogen can range from mild self-limiting illness to severe and refractory cases. Complications may occur, such as necrotizing pneumonia and respiratory failure. Extrapulmonary complications, including encephalitis, myocarditis, nephritis, hepatitis, or even multiple organ failure, can also arise. In this editorial, we discuss the clinical implications of the significant findings from the article "Serum inflammatory markers in children with M. pneumoniae pneumonia and their predictive value for mycoplasma severity" published by Wang et al. They reported that measuring lactic dehydrogenase, interleukin-6 levels, and D-dimer effectively predicts refractory M. pneumoniae pneumonia cases.

Pulmonary thromboembolism due to Mycoplasma pneumoniae in children: a case report and literature review

BACKGROUND

Mycoplasma pneumoniae (MP) is a common respiratory pathogen in children that can sometimes lead to extrapulmonary manifestations. Among these, pediatric pulmonary thromboembolism (PE) is clinically rare but carries significant implications. However, it is often underrecognized, and its diagnosis and treatment are not well understood.

CASE PRESENTATION

We report a case of PE associated with MP pneumonia in a 6-year-old girl who presented with recurrent hyperpyrexia, cough, extensive consolidation in the upper lobe of the left lung, and pulmonary artery thrombi in the right lung. Following prompt diagnosis of PE and appropriate antibiotic therapy combined with anticoagulation treatment, the child recovered well and remained healthy at follow-up. The diagnostic and treatment processes were analyzed, and previously reported cases of pediatric MP-related PE were reviewed.

CONCLUSION

PE should be considered in pediatric patients with MP pneumonia who do not improve or whose condition worsens despite standard therapy. The outcomes of pediatric MP-related PE are generally favorable if prompt diagnosis and appropriate treatment are provided.

Clinical characteristics and risk factors of pulmonary embolism with Mycoplasma pneumoniae pneumonia in children

Pulmonary embolism is a rare but serious complication in Mycoplasma pneumoniae pneumonia patients, leading to serious sequelae and even death. We aim to retrospectively analyze the clinical features of Mycoplasma pneumoniae pneumonia with pulmonary consolidation in children and to explore the independent risk factors for progression to pulmonary embolism. Clinical data of 207 children with Mycoplasma pneumoniae pneumonia complicated with pulmonary consolidation were collected, and the patients were divided into the pulmonary embolism group (69 patients) and the control group (138 patients). Multivariate logistic regression was used to analyze the risk factors and the predictive efficacy was evaluated by receiver operating characteristic curve. Multivariate logistic regression analysis showed that fever days, D-dimer, immunoglobulin A, chest pain, extra-respiratory symptoms, plastic bronchitis and cutaneous mucosal system complications were the independent risk factors. Fever days ≥ 7.5, D-dimer ≥ 0.895 mg/L, immunoglobulin A ≥ 1.015 g/L, chest pain, extra-respiratory symptoms, plastic bronchitis and cutaneous mucous system complications significantly increased the risk of pulmonary embolism in children with Mycoplasma pneumoniae pneumonia complicated with pulmonary consolidation.

Clinical profiles of Mycoplasma pneumoniae pneumonia in children with different pleural effusion patterns: a retrospective study

BACKGROUND

The clinical significance of the presence or absence of Mycoplasma pneumoniae (MP) in pleural effusion in Mycoplasma pneumoniae pneumonia (MPP) children has not yet been elucidated. Herein, we investigated the clinical implication of pleural fluid MP positive in children with MPP.

METHODS

A total of 165 MPP children with pleural effusion requiring thoracocentesis were enrolled in this study. They were subsequently divided into two groups according to the presence or absence of MP in pleural effusion, namely positive group (n = 38) and negative group (n = 127). Information on their clinical manifestations, laboratory findings, radiological characteristics and treatment modalities was retrospectively collected from medical chart reviews.

RESULTS

The length of hospitalization (15.00 (10.75-19.25) vs. 11.00 (9.00-14.00) days, p=0.001) and total course of illness (23.00 (18.00-28.00) vs. 20.00 (17.00-24.00) days, p=0.010) were significantly longer in the positive group than in the negative group. The occurrence of pericardial effusion (23.7% vs. 7.9%, p=0.017), atelectasis (73.7% vs. 53.5%, p=0.027) and necrotizing pneumonia (23.7% vs. 7.9%, p=0.017) were more frequent in the positive group compared to the negative group. The levels of neutrophil percentages (82.35% (75.40%-85.78%) vs. 72.70% (64.30%-79.90%), p<0.001), C-reactive protein (CRP) (71.12 (37.75-139.41) vs. 31.15 (13.54-65.00) mg/L, p<0.001), procalcitonin (PCT) (0.65 (0.30-3.05) vs. 0.33 (0.17-1.13) ng/ml, p=0.005), serum lactate dehydrogenase (LDH) (799.00 (589.00-1081.50) vs. 673.00 (503.00-869.00) U/L, p=0.009), D-dimer (6.21 (3.37-16.11) vs. 3.32 (2.12-6.62) mg/L, p=0.001) on admission were significantly higher in the positive group than in the negative group. These pronounced differences significantly contributed to the identification of MPP with MP positive pleural effusion, as evidenced by the ROC curve analysis. Marked elevations in adenosine deaminase (49.25 (36.20-60.18) vs. 36.20 (28.10-46.50) U/L, p<0.001) and LDH levels (2298.50 (1259.75-3287.00) vs. 1199.00 (707.00-1761.00) U/L, p<0.001) were observed in pleural fluid of the positive group when compared to the negative group. Meanwhile, the number of patients on low molecular weight heparin (LMWH) therapy (9 (23.7%) vs. 12 (9.4%), p=0.028) was higher in the positive group. Multivariate logistic regression analysis revealed that D-dimer > 7.33 mg/L was significantly associated with the incidence of MP positive pleural effusion in MPP (OR=3.517).

CONCLUSIONS

The presence of MP in pleural fluid in MPP children with pleural effusion indicated a more serious clinical course. D-dimer > 7.33 mg/L was a related factor for MP positive pleural effusion in MPP. The results of the present study would help in the creation of a therapeutic plan and prediction of the clinical course of MPP in children.

miR-483-5p-Containing exosomes treatment ameliorated deep vein thrombosis‑induced inflammatory response

Peripheral vascular condition, known as deep vein thrombosis (DVT), is a common ailment that may lead to deadly pulmonary embolism. Inflammation is closely connected to venous thrombosis, which results in blood stasis, leading to ischemia and hypoxia, as indicated by research. The objective of this research was to investigate the mechanism by which exosomes derived from adipose stem cells (ADSCs) prevent deep vein thrombosis. Our data showed that Exo-483 effectively reduced the thrombus weight in DVT rats by intravenous injection. Exo-483 decreased the expression of tissue factor (TF) protein, the influx of inflammatory cells into the thrombosed vein wall, and the levels of cytokines in the serum. Furthermore, Exo-483 suppressed the expression of Mitogen-activated protein kinase 1 (MAPK1) and decreased the expression of NLRP3 inflammasomes. In an oxygen-glucose deprivation (OGD) cell model, the tube-forming and migratory abilities of primary human umbilical vein endothelial cells (HUVEC) and EA.hy926 cells were suppressed by Exo-483 pretreatment.Exo-483 is also linked to regulating Dynamin-related protein 1 (DRP1) production downstream of MAPK1.By decreasing the mitochondrial localization and phosphorylation at the S616 site of DRP1, it diminishes the expression of NLRP3 inflammasomes. Moreover, according to Bioinformatics analysis, miR-483-5p was anticipated to target MAPK1. The research conducted by our team revealed that the miR-483-5p exosome derived from ADSCs exhibited anti-inflammatory properties through the modulation of downstream DRP1-NLRP3 expression by targeting MAPK1.The findings of this research propose that miR-483-5p may be regarded as an innovative treatment target for DVT.

Serum inflammatory markers in children with Mycoplasma pneumoniae pneumonia and their predictive value for mycoplasma severity

BACKGROUND

Mycoplasma pneumoniae pneumonia (MPP) significantly impacts pediatric health, necessitating markers for early severe disease identification.

AIM

To investigate the correlation between serum inflammatory marker and the severity of MPP in children.

METHODS

A prospective study was carried out from January 2023 to November 2023. A total of 160 children with MPP who underwent treatment were selected: 80 had severe MPP and 80 had mild MPP. Clinical and laboratory data were collected at the time of hospital admission and during hospitalization. Receiver operating characteristic curves were utilized to assess the diagnostic and prognostic for severe MPP.

RESULTS

Fever duration and length of hospitalization in pediatric patients with severe MPP exceeded those with mild MPP. The incidence of pleural effusion, lung consolidation, and bronchopneumonia on imaging was markedly elevated in the severe MPP cohort compared to the mild MPP cohort. In contrast to the mild cohort, there was a notable increase in C-reactive protein (CRP), procalcitonin (PCT), erythrocyte sedimentation rate, lactic dehydrogenase, D-dimer, and inflammatory cytokines [interleukin (IL)-6, IL-8, IL-10 and tumor necrosis factor (TNF)-α] in the severe MPP group were significantly higher.

CONCLUSION

Serum inflammatory markers (CRP, PCT, IL-6, D-dimer, IL-10 and TNF-α) were considered as predictors in children with severe MPP.

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.

Evaluation and clinical significance of serum neurospecific enolase in children with pneumonia: a case-control study

BACKGROUND

Neurospecific Enolase (NSE), a multifunctional protein, is present in various tissues of the body and plays an important role in many disease processes, such as infection, inflammation, tumours, injury, and immunity. In recent years, the application of NSE in respiratory diseases has become increasingly widespread and a research hotspot.

OBJECTIVE

This study aims to explore the relationship between NSE and childhood pneumonia, providing assistance for the diagnosis and assessment of pneumonia.

METHODS

Using prospective research and case-control methods, We selected 129 children with pneumonia hospitalised in Weifang People's Hospital from September 2020 to April 2022 as the case group. Among them were 67 cases of Mycoplasma pneumoniae pneumonia (MP+), 62 cases of non-Mycoplasma pneumoniae pneumonia (MP -), and 21 cases of severe pneumonia. At the same time, 136 children who underwent outpatient health examinations were selected as the control group. The levels of NSE, ESR, CRP in cases group and NSE in control group were measured separately.

RESULT

The NSE levels in the MP + group were 17.86 (14.29-22.54) ng/mL, while those in the MP- group were 17.89 (14.10-21.66) ng/mL, both of which were higher than the control group's NSE levels of 13.26(12.18,14.44) ng/mL (H = 46.92, P = 0.000). There was no statistically significant difference in NSE levels between the MP + and MP - groups (P > 0.05). The NSE level in the severe pneumonia group was 27.38 (13.95-34.06) ng/mL, higher than that in the mild pneumonia group, which was 17.68 (14.27-21.04) ng/mL, (P = 0.024). The AUC values for diagnosing pneumonia are NSE0.714, CRP0.539, and ESR0.535, with NSE having the highest diagnostic value.

CONCLUSION

Serum NSE can serve as an inflammatory indicator for paediatric pneumonia, which has important clinical guidance significance for the diagnosis, condition evaluation, and prognosis of paediatric pneumonia.

Characteristics and Outcomes of Mycoplasma Pneumoniae Pneumonia Associated with Pulmonary Embolism and Necrotizing Pneumonia in Children

Purpose

To explore the clinical characteristics, treatment, and long-term prognosis of mycoplasma pneumoniae pneumonia (MPP) combined with pulmonary embolism (PE) in children.

Patients and Methods

The medical records of 16 children who were diagnosed with MPP associated with PE between January 2016 and January 2023 at Children's Hospital, Zhejiang University School of Medicine were retrospectively reviewed.

Results

The average age patients were 8.24 ± 1.99 years. All cases were diagnosed with refractory mycoplasma pneumoniae pneumonia (RMPP) and presented complications in the form of necrotizing pneumonia (NP). The main symptoms observed were cough and fever (n = 16, 100%), chest pain (n = 8, 50%), dyspnea (n = 8, 50%), and hemoptysis (n = 4, 25%). In these cases, 12 patients had involvement of the pulmonary artery, 3 patients experienced issues with the pulmonary vein, and 1 patient had simultaneous involvement of both the pulmonary artery and pulmonary vein. Among the 12 pulmonary artery embolism cases, 6 involved the right pulmonary artery, 4 involved the left pulmonary artery, and 2 involved both the right and left pulmonary arteries. The mean D-dimer level was 8.50 ± 4.76 mg/L. All patients received anticoagulant therapy, and after treatment, there was a significant improvement in their symptoms and lung lesions.

Conclusion

Children with RMPP, chest pain, hemoptysis, and elevated D-dimer levels should be closely monitored for the potential development of PE. The co-occurrence of MPP and PE often involves the presence of NP. In cases of confirmed PE, anticoagulation therapy may be a suitable consideration. PE and NP resulting from MPP generally had a favorable overall prognosis.

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.

Changes in coagulation markers in children with Mycoplasma pneumoniae pneumonia and their predictive value for Mycoplasma severity

BACKGROUND

This study investigates the correlation between coagulation levels and the severity of Mycoplasma pneumoniae pneumonia (MPP) in children. In addition, the study analyses the predictive value of coagulation abnormalities in MPP combined with necrotising pneumonia (NP).

METHODS

A total of 170 children with MPP who underwent treatment between June 2021 and February 2022 were selected for this study. The study population was divided into groups according to the severity of the disease to compare differences in the incidence of coagulation abnormalities between the groups. The participants were also divided into groups according to imaging manifestations to compare the differences in coagulation function among the different groups. All data information was processed for statistical analysis using SPSS Statistics 25.0 and GraphPad Prism 7.0 statistical analysis software.

RESULTS

The incidence of coagulation abnormalities in the children in the severe MPP (SMPP) group was significantly higher than that in the normal MPP (NMPP) group (P < 0.05). The multi-factor logistic regression analysis revealed that the D-dimer level is an independent risk factor for the development of NP in SMPP (P < 0.05). The receiver operating characteristic curve analysis revealed statistically significant differences (P < 0.05) in D-dimer, fibrinogen degeneration products (FDP), neutrophils, lactate dehydrogenase and serum ferritin for predicting SMPP combined with NP. Bronchoscopic manifestations of coagulation indicators (D-dimer and FDP levels) were significantly higher in the mucus plug group than in the non-mucus plug group, while the activated partial thromboplastin time levels were lower in the former than in the latter (P < 0.05).

CONCLUSION

The degree of elevated D-dimer and FDP levels was positively correlated with the severity of MPP, with elevated serum D-dimer levels (> 3.705 mg/L) serving as an independent predictor of MPP combined with NP in children.

Clinical characteristics and serum inflammatory markers of community-acquired mycoplasma pneumonia in children

BACKGROUND

To compare the demographic and clinical features, laboratory and imaging findings in mycoplasma pneumoniae pneumonia (MPP) children with non-MPP (NMPP) children and general MPP (GMPP) children with refractory MPP (RMPP) children and analysis the relationship with the severity of disease.

METHODS

The study included 265 children with MPP and 230 children with NMPP in the Affiliated Changzhou No. 2 People's Hospital of Nanjing Medical University from 2020 to 2021. The children with MPP included RMPP (n = 85) and GMPP (n = 180). Demographic and clinical characteristics, laboratory and imaging findings of all children were measured as baseline data within 24 h after admission and the differences between MPP and NMPP, RMPP and GMPP patients were compared. ROC curves were used to evaluate the diagnostic and predictive value of different indicators for RMPP.

RESULTS

Fever duration and hospital stay in children with MPP were longer than those with NMPP. The number of patients with imaging features of pleural effusion, lung consolidation and bronchopneumonia in MPP group was significantly higher than that in NMPP group. Compared with NMPP group, the levels of C-reactive protein (CRP), procalcitonin (PCT), serum amyloid A (SAA), erythrocyte sedimentation rate (ESR), lactic dehydrogenase (LDH), prothrombin time (PT), fibrinogen (FIB) and D-dimer and inflammatory cytokines (interleukin [IL]-6, IL-8, IL-10 and IL-1β) in MPP group were significantly higher (P < 0.05). The clinical symptoms and pulmonary imaging findings were more severe in RMPP group. The levels of white blood cell (WBC), CRP, PCT, SAA, ESR, alanine aminotransferase (ALT), LDH, ferritin, PT, FIB, D-dimer and inflammatory cytokines in RMPP group were higher than those in GMPP group. There was no significant difference in the level of lymphocyte subsets between the RMPP and GMPP group. IL-6, IL-10, LDH, PT, D-dimer and lung consolidation were independent risk factors for RMPP. IL-6 levels and LDH activity were good predictors of RMPP.

CONCLUSION

In conclusion, there were differences in clinical characteristics and serum inflammatory markers between MPP group and NMPP group, RMPP group and GMPP group. IL-6, IL-10, LDH, PT and D-dimer can be used as predictive indicators for RMPP.

Thromboembolic complications of Mycoplasma pneumoniae pneumonia in children

BACKGROUND

Thromboembolism is less common in children than in adults, but it is frequently associated with Mycoplasma pneumoniae infection in many cases. This study aimed to investigate the clinical characteristics of pediatric M. pneumoniae pneumonia complicated with thromboembolism.

METHODS

Hospitalized patients with M. pneumoniae pneumonia complicated by thromboembolism were enrolled from January 2012 to December 2021 in Beijing Children's Hospital, Capital Medical University, China. The data on clinical manifestations, laboratory tests, and treatment were evaluated.

RESULTS

A total of 49 cases were enrolled, with a mean age of 7.9 years old, including 27 boys and 22 girls. Consolidation of pulmonary lobe or segment was observed in 95.9% (47/49) of the cases, whereas interstitial change was found only in two patients; 85.7% (42/49) of patients had pleural effusion. Pulmonary vascular thromboembolism was most common in 35 patients, whereas 13 cases had thromboembolism of multiple anatomic sites. The levels of C-reaction protein, lactate dehydrogenase, and erythrocyte sedimentation rate were all increased, with a mean value of 54.08 ± 52.27 g/L, 451.12 ± 218.76 U/L, 43.40 ± 29.43 mm/h, respectively. Blood coagulation test showed that all 49 patients had elevated D-dimer values (median 3.81 ng/ml, range, 0.34-48 ng/ml) and normal PT. aPTT.LA was positive in 74.3% (26/35) of the cases. aCL-IgM was positive in 66.7% (26/39) of the cases. aβ2GPI-IgM was positive in 79.4% (27/34) of the cases. The prognosis was generally good in this group.

CONCLUSION

Pulmonary arteriovenous thromboembolism is the most common thromboembolism complicated in MPP, and cerebral artery embolism and cardiac thrombosis are common in extrapulmonary thromboembolism. In the cases of MPP with thromboembolic complications, pulmonary consolidation with pleural effusion is the main characteristic. About two thirds of the cases are positive for antiphospholipid antibodies.

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.

Analysis of Clinical Related Factors of Severe Mycoplasma pneumoniae Pneumonia in Children Based on Imaging Diagnosis

Severe pneumonia is a common acute respiratory disease in children, and it has a rapid onset and violent onset, which often affects the whole body. Moreover, typical clinical manifestations and signs often cannot be taken seriously or covered up in clinical work. Due to the short time for treatment, it is easy to cause improper diagnosis and treatment, aggravate the disease and further deteriorate, and even threaten the life of the child. In order to achieve early intervention and treatment of severe Mycoplasma pneumoniae pneumonia in children, reduce or shorten the course of the disease, and improve the cure rate, this paper combines the imaging diagnosis to study the analysis of clinical related factors of severe Mycoplasma pneumoniae pneumonia in children. In addition, this paper analyzes the experimental data with hospital case samples, conducts statistical research on the analysis of clinical related factors of severe Mycoplasma pneumoniae pneumonia in children, and proposes effective coping strategies.

Value of D-dimer in predicting various clinical outcomes following community-acquired pneumonia: A network meta-analysis

Background

Whether high D-dimer level before treatment has any impact on poor outcomes in patients with community-associated pneumonia (CAP) remains unclear. Therefore, we conducted the first meta-analysis focusing specifically on prognostic value of high D-dimer level before treatment in CAP patients.

Methods

Pubmed, Embase, the Cochrane Central Register of Controlled Trials and World Health Organization clinical trials registry center were searched up to the end of March 2021. Randomized clinical trials (RCT) and observational studies were included to demonstrate the association between the level of D-dimer and clinical outcomes. Data were extracted using an adaptation of the Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies (CHARMS-PF). When feasible, meta-analysis using random-effects models was performed. Risk of bias and level of evidence were assessed with the Quality in Prognosis Studies tool and an adaptation of Grading of Recommendations Assessment, Development, and Evaluation. Data were analyzed using STATA 14.0 to complete meta and network analysis.

Main outcomes and measures

Besides d-dimer levels in CAP patients with poor outcomes, we also analyzed proportion of patients with or without poor outcomes correctly classified by the d-dimer levels as being at high or low risk. The poor outcome includes severe CAP, death, pulmonary embolism (PE) and invasive mechanical ventilators.

Results

32 studies with a total of 9,593 patients were eventually included. Pooled effect size (ES) suggested that d-dimer level was significantly higher in severe CAP patients than non-severe CAP patients with great heterogeneity (SMD = 1.21 95%CI 0.87–1.56, I² = 86.8% p = 0.000). D-dimer level was significantly elevated in non-survivors compared to survivors with CAP (SMD = 1.22 95%CI 0.67–1.77, I² = 85.1% p = 0.000). Prognostic value of d-dimer for pulmonary embolism (PE) was proved by hierarchical summary receiver operating characteristic curve (HSROC) with good summary sensitivity (0.74, 95%CI, 0.50–0.89) and summary specificity (0.82, 95%CI, 0.41–0.97). Network meta-analysis suggested that there was a significant elevation of d-dimer levels in CAP patients with poor outcome than general CAP patients but d-dimer levels weren’t significantly different among poor outcomes.

Conclusion

The prognostic ability of d-dimer among patients with CAP appeared to be good at correctly identifying high-risk populations of poor outcomes, suggesting potential for clinical utility in patients with CAP.

Analysis of the Nursing Effect of Respiratory Critical Illness Based on Refined Nursing Management

In order to improve the nursing effect of respiratory critical illness, this paper combines the refined nursing method to explore the nursing plan of respiratory critical illness. Moreover, this paper uses the variable control method to explore the effects of nursing management, combines the hospital patient samples to conduct a controlled trial analysis, and conducts sample grouping according to the random grouping method. The patients in the control group are managed by traditional nursing management methods, the patients in the test group are managed by refined nursing management methods, and other conditions are basically the same. In addition, the experiment process variable control is carried out according to the mathematical statistics method, and the reasonable statistics and data processing are carried out. Through the comparison method, we can see that the refined management method proposed in this paper has a good effect in the nursing of respiratory critical illness.

[The Association between the Level of Plasma D-dimer and Disease Severity and Prognosis of Mycoplasma pneumoniae Pneumonia in Children]

OBJECTIVE

To explore the association between the levels of plasma D-dimer and the disease severity and prognosis of Mycoplasma pneumoniae pneumonia (MPP) in children.

METHODS

We retrospectively analyzed the clinical data of pediatric MPP patients who were admitted in our hospital between January 1, 2016 and December 31, 2018. According to the peak value of D-dimer, patients were divided into the normal group (D-dimer<0.55 mg/L) and the elevated group (D-dimer≥0.55 mg/L). Information regarding the demographics, clinical manifestations, auxiliary examinations and treatments of patients in the two groups was compared.

RESULTS

Of the 231 MPP patients included in the study, 70 were in the normal group and 161 were in the elevated group. The age of patients in the D-dimer elevated group was significantly higher than that of the normal group ( P<0.01). Compared with the normal group, the elevated group had longer lengths of fever, hospital stay and antibiotic therapy, and more severe radiographic manifestations (all P<0.01). In addition, the incidence of extrapulmonary complications, refractory MPP and severe MPP in the elevated group were significantly higher than those in the normal group ( P<0.01). As for the laboratory data, we found that neutrophils, C-reactive protein, lactate dehydrogenase, interleukin-6, interleukin-10 and interferon-γ were significantly higher in the elevated group than those in the normal group ( P<0.05). After treatments, all patients showed improvement and were discharged, but the proportions of patients requiring glucocorticoids, bronchoscopy, thoracentesis were significantly higher in the elevated group than those in the normal group ( P<0.05). Follow-up findings showed that the absorption rate of lung lesions 4 weeks after admission was significantly higher, the time needed for lung lesions absorption was significantly shorter, and the incidence of pulmonary sequelae was significantly lower in the normal group than those in the elevated group (all P<0.05). Correlation analysis showed that D-dimer level was positively correlated with the severity of pneumonia ( r=0.272, P=0.000) and the incidence of pulmonary sequelae ( r=0.235, P=0.000).

CONCLUSION

Pediatric patients of MPP who had elevated plasma D-dimer had clinical manifestations that were more severe, required longer duration of treatment and longer recovery time for lung lesions, and were more likely to have pulmonary sequelae.

Assessment of mechanisms of infectious pneumonia based on expression of fibrinogen, procalcitonin, high-sensitivity C-reactive protein expression, T helper 17 cells, regulatory T cells interleukin-10, and interleukin-17

BACKGROUND

Infectious pneumonia is one of the important causes of neonatal death that can lead to the imbalance of T helper 17 cells (Th17) and T regulatory T cells (Treg) cells. The correlation between plasma fibrinogen (FIB), procalcitonin (PCT), C-reactive protein (CRP) and Th17/Treg-IL-10/IL-17 axis balance and their specific role in the occurrence and development of infectious pneumonia are not completely clear.

METHODS

Thirty specific-pathogen free Sprague Dawley (SD) rats were randomly divided into a control group for comparison and IPN model group. After the establishment of infectious pneumonia model, levels of FIB, PCT, hs-CRP, IL-10, and IL-17 in the serum of the two groups were measured using enzyme linked immunosorbent assay (ELISA), the pathological changes of lung tissue were observed using hematoxylin and eosin (HE) staining, the number of Treg and Th17 cells and the ratio of Th17/Treg in serum were detected using flow cytometry, and the levels of retinoic acid-related orphan receptor γt and forkhead box P3 (FOXP3) in lung tissue were detected using reverse transcription polymerase chain reaction (RT-PCR) and western blot.

RESULTS

The results showed that the serum levels of FIB, PCT, hs-CRP, Th17 cell number, Th17/Treg ratio, left lung dry and wet weight, lung tissue wet/dry ratio, lung pathology score and IL-17 level in the model group were significantly higher than those in the control group, while the number of Treg cells and the level of IL-10 in the model group were significantly lower than those in the control group. In addition, the expression of Foxp3mRNA and protein in lung tissue of model group decreased significantly, while the expression level of ROR- γ t mRNA and protein increased.

CONCLUSIONS

In infectious pneumonia, the expression levels of FIB, PCT and hs-CRP are up-regulated, and Th17 cells are activated, Treg cells are inhibited, proinflammatory cytokine IL-17 expression is up-regulated, anti-inflammatory cytokine IL-10 expression is down-regulated, resulting in increased inflammatory response, thus promoting the occurrence and development of infectious pneumonia.

The Level of D-Dimer Is Positively Correlated With the Severity of Mycoplasma pneumoniae Pneumonia in Children

Objective

Mycoplasma pneumoniae pneumonia (MPP) is an important disease in children. Studies have demonstrated that the levels of D-dimer are elevated in some children with MPP, especially those with thrombotic complications. However, the potential association between MPP and D-dimer remains unclear. In our study, we sought to explore the relationship between the levels of plasma D-dimer and clinical characteristics of MPP patients.

Methods

Retrospective analysis was conducted on 356 patients who were hospitalized in our hospital for MPP between January 1, 2017, and December 31, 2019. According to the peak value of D-dimer, patients were divided into three groups: the normal group (D-dimer<0.55 mg/L), the mild-moderately elevated group (D-dimer 0.55–5.5 mg/L) and the severely elevated group (D-dimer >5.5 mg/L). The demographic and clinical information, radiological findings, laboratory data, and treatments of patients were compared among different groups.

Results

106 patients were in the normal group, 204 patients were in the mild-moderately elevated group, and 46 patients were in the severely elevated group. More severe clinical and radiographic manifestations, longer length of fever, hospital stay and antibiotic therapy duration, higher incidences of extra-pulmonary complications, refractory MPP (RMPP), severe MPP (SMPP) were found in the elevated group, when compared with the normal group (P<0.01). Meanwhile, we found that the percentage of neutrophil (N%) and CD₈⁺ lymphocyte (CD₈⁺%), C-reactive protein (CRP), lactate dehydrogenase (LDH), interleukin (IL)-6, IL-10, and interferon-gamma (IFN-γ) trended higher with increasing D-dimer, whereas the percentage of lymphocyte (L%) and prealbumin (PAB) trended lower (P<0.01). In addition, the proportions of patients requiring oxygen therapy, glucocorticoid, bronchoscopy, immunoglobulin use, thoracentesis, or ICU admission were significantly higher in the severely elevated group than those in the other two groups (P<0.01). Correlation analysis showed that N%, L%, CRP, LDH, IL-10, length of fever, length of stay, and length of antibiotic therapy had strong correlations with the level of D-dimer.

Conclusions

MPP patients with higher levels of D-dimer had more severe clinical manifestations and needed longer duration of treatment, which might be closely related to the severity of lung inflammation after MP infection.

Thrombosis associated with mycoplasma pneumoniae infection (Review)

Mycoplasma pneumoniae is a common pathogen causing respiratory infections in children and adults. In addition to respiratory diseases, Mycoplasma pneumoniae is also involved in numerous extrapulmonary diseases. Thrombosis is an extrapulmonary manifestation associated with Mycoplasma pneumoniae infection. In recent years, an increasing number of case reports have been published identifying thrombosis secondary to Mycoplasma pneumoniae infection. In the present study, the available relevant literature in English available on PubMed, Medline and Web of Science was consulted. The results of the present study demonstrated that in patients with thrombosis caused by Mycoplasma pneumoniae infection, some of the factors causing thrombosis are transient and some are due to hereditary thrombophilia. Following timely treatment, the majority of patients recovered completely but some patients had a poor prognosis. The present review focuses on the pathogenesis, clinical features, treatment and prognosis of this crucial issue, which contributes toward the understanding of the disease.

Dynamic Changes in Coagulation Function in Patients With Pneumonia Under Admission and Non-admission Treatment

Objective: We aimed to explore the dynamic changes in coagulation function and the effect of age on coagulation function in patients with pneumonia under admission and non-admission treatment. Methods: We included 178 confirmed adult inpatients with COVID-19 from Wuhan Union Hospital Affiliated to Huazhong University of Science and Technology (Wuhan, China). Patients were classified into common types, and all were cured and discharged after hospitalization. We recorded the time of the first clinical symptoms of the patients and performed blood coagulation tests at the time of admission and after admission. In total, eight factors (TT, FIB, INR, APTT, PT, DD, ATIII, and FDP) were analyzed. Patients were classified into four groups according to the time from the first symptom onset to hospital admission for comparative analysis. The patients who were admitted within 2 weeks of disease onset were analyzed for the dynamic changes in their blood coagulation tests. Further division into two groups, one group comprising patients admitted to the hospital within 2 weeks after the onset of disease and the other comprising patients admitted to the hospital 2 weeks after disease onset, was performed to form two groups based on whether the patient ages were over or under 55 years. Chi-square tests and T tests were used to explore the dynamic changes in coagulation function and the influence of age on the results of coagulation function tests. Results: A total of 178 inpatients, 34 of whom underwent dynamic detection, were included in this analysis. We divided these patients into four groups according to the interval between the onset of COVID-19 pneumonia and the time to admission in the hospital: the 1-7 days (group 1), 8-14 days (group 2), 15-21 days (group 3), and >21-days (group 4). Eight factors all increased within 2 weeks after onset and gradually decreased to normal 2 weeks before the patient was admitted. The changes in coagulation function of patients admitted to the hospital were similar. After being admitted to the hospital, the most significant decreases among the eight factors were between week 2 and 3. There were distinct differences among the eight factors between people older than 55 years and those younger than 55 years. In the first 2 weeks after being admitted, the levels of the eight factors in patients >55 years were significantly higher than those in patients <55 years, and after another 2 weeks of treatment, the factor levels in both age groups returned to normal. Conclusion: The eight factors all increased within 2 weeks after onset and gradually decreased to normal after 2 weeks regardless of treatment. Compared with patients younger than 55 years, patients older than 55 years have greater changes in their blood coagulation test values.

Two new inflammatory markers related to the CURB-65 score for disease severity in patients with community-acquired pneumonia: The hypersensitive C-reactive protein to albumin ratio and fibrinogen to albumin ratio

Background

The objective of this study was to investigate the relationship among hypersensitive C-reactive protein to albumin ratio (CAR), fibrinogen to albumin ratio (FAR), and the CURB-65 score for community-acquired pneumonia (CAP) severity.

Methods

Clinical data and laboratory indicators of 82 patients with CAP and 40 healthy subjects were retrospectively analysed. The relationship among CAR, FAR, and the severity of CAP was then analysed.

Results

CAR and FAR in patients with low-risk CAP were significantly higher than those in the normal control group (P < 0.05). CAR and FAR in patients with medium-high-risk CAP were further increased compared with those in patients with low-risk CAP (P < 0.05). CAR and FAR were positively correlated with hypersensitive C-reactive protein, neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and CURB-65 scores (P < 0.05). In the receiver operating characteristic curve for predicting severe CAP, the area under the curve of combining four biomarkers (CAR + FAR + NLR + PLR) was the largest. CAR was also an independent risk factor for severe CAP (OR = 8.789, 95% CI: 1.543-50.064, P = 0.014).

Conclusions

CAR and FAR may be used as the inflammatory markers for CAP severity evaluation.

An Unusual Case of Myocarditis, Left Ventricular Thrombus, and Embolic Stroke Caused by Mycoplasma pneumoniae

Mycoplasma pneumoniae is a common cause of community-acquired pneumonia, but it can affect other parts of the body. Due to the varied presentation and lack of readily available specific diagnostic tools, diagnosis is often challenging, which may lead to delay in the treatment and unfavorable outcomes. We describe such a unique case of myocarditis caused by Mycoplasma pneumoniae complicated by left ventricular thrombus and an embolic stroke without the presence of pneumonia. There is a paucity of data regarding Mycoplasma pneumoniae myocarditis and stroke in the absence of pulmonary symptoms especially in adults, calling for further studies for early diagnosis and management.

Evaluation on blood coagulation and C-reactive protein level among children with mycoplasma pneumoniae pneumonia by different chest imaging findings

Mycoplasma pneumoniae infection may induce a systemic hypercoagulable abnormality, like organ embolism and infarction. Indexes of blood coagulation and C-reactive protein (CRP) have been reported different between healthy people and mycoplasma pneumoniae pneumonia (MPP) patients, but this difference in MPP patients with different chest imaging findings has rarely been reported.We performed a retrospective study of 101 children with MPP and 119 controls, combined with radiological examination and blood tests, to compare the blood coagulation and CRP level among MPP children with different chest imaging findings.For the MPP children with different chest imaging findings, there were significant differences in CRP, fibrinogen (FIB) and D-dimer (D-D) levels among subgroups (P = .004, P = .008 and P < .001 respectively). The CRP level in group of interstitial pneumonia was significantly higher than that in groups of bronchopneumonia and hilar shadow thickening (P = .003 and P = .001 respectively). And the FIB and D-D values in group of lung consolidation were significantly higher than that in the other 3 groups (all P < .05). When compared with controls, the white blood cell, CRP, FIB, and D-D levels in MPP children were significantly higher, and the activated partial thromboplastin time and thrombin time levels were significantly lower (all P < .05).Our results showed that CRP level changed most significantly in group of interstitial pneumonia, whereas FIB, D-D levels changed most significantly in the lung consolidation group.

Mycoplasma pneumoniae pneumonia with pulmonary embolism: A study on pediatric cases in Jilin province of China

Mycoplasma is one of the most common pathogens causing community-acquired pneumonia in pediatric patients. In recent years, the number of refractory or severe cases with drug resistance has been gradually increasing and cases that developed embolism after Mycoplasma pneumoniae (M. pneumoniae) infection have been reported. The present study retrospectively analyzed the clinical features, diagnosis and treatment of M. pneumoniae pneumonia (MPP) combined with pulmonary embolism (PE) in a series of 7 cases encountered between January 1st, 2016 to August 1st, 2019 at the Department of Pediatric Intensive Care Unit of The First Hospital of Jilin University (Changchun, China). Combined with relevant Chinese and international studies published during the last two decades, a comprehensive analysis was performed. All of the pediatric patients of the present study had fever, cough and dyspnea respiratory symptoms at onset and the disease progressed rapidly. Thereafter, PE was confirmed by a series of examinations. Pulmonary CT indicated patchy inflammations and significantly elevated D-dimer levels, accompanied by positive anticardiolipin antibodies. Furthermore, a filling defect in the pulmonary artery branch was observed on CT pulmonary angiography (CTPA) examination. In 2 cases, the condition was improved with anti-infection and anticoagulation treatment with low-molecular-weight heparin and warfarin, respectively, and the pulmonary embolism disappeared after 3-4 months. A total of 5 cases, who were not responsive to the drug treatment, underwent surgical resection. During the operation, the local tissues were determined to be infarcted and the pathological diagnosis was consistent with pulmonary infarction. Among the 5 cases, 2 died of Acute Respiratory Distress Syndrome at 3-8 days after the operation. The remaining patients underwent 6-12 months of follow-up and respiratory rehabilitation and their quality of life is now good. In conclusion, compared with healthy individuals, pediatric patients with critical MPP have an elevated risk of embolism. It is necessary to be vigilant regarding whether MMP is combined with PE and perform timely CTPA examination. Early detection, early treatment and surgical intervention (if necessary) may significantly reduce the risk of mortality and disability.

Clinical significance of D-dimer levels in refractory Mycoplasma pneumoniae pneumonia

BACKGROUND

The levels of serum D-dimer (D-D) in children with Mycoplasma pneumoniae pneumonia (MPP) were assessed to explore the clinical significance of D-D levels in refractory MPP (RMPP).

METHOD

A total of 430 patients with MPP were enrolled between January 2015 and December 2015 and divided into a general MPP (GMPP) group (n = 306) and a RMPP group (n = 124). Clinical data, D-D level, white blood cell (WBC) count, proportion of neutrophils (N%), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), alanine transaminase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were compared between the two groups. Multivariate logistic regression was performed to identify independent predictors of RMPP.

RESULTS

(1) Hospitalization time, preadmission fever duration, total fever duration, WBC, N %, CRP, LDH, ESR, ALT, AST, and D-D were significantly higher in the RMPP group than those in the GMPP group (all P < 0.05). (2) Correlation analysis showed that D-D was positively correlated with WBC, CRP, ESR, and LDH, and could be used to jointly evaluate the severity of the disease. (3) Multivariate logistic regression analysis identified preadmission fever duration, CRP, LDH and DD as independent risk factors for RMPP (all P < 0. 05). D-D had the highest predictive power for RMPP (P < 0.01). The D-D level also had a good ability to predict pleural effusion and liver injury (all P < 0.01).

CONCLUSION

Serum D-D levels were significantly increased in patients with RMPP, indicating that excessive inflammatory response and vascular endothelial injury with prolonged duration existed in this patient population. Increased levels of serum D-D may be used as an early predictor of RMPP and the occurrence of complications. Our findings provide a theoretical basis for the early diagnosis of RMPP, early intervention and excessive inflammatory response in the pathogenesis of mycoplasma.

Deep Vein Thrombosis and Pulmonary Embolism in the Setting of Mycoplasma Infection

Thirteen-year-old female twins presented one week apart with documented Mycoplasma pneumoniae respiratory infection. Each developed venous thrombosis and pulmonary emboli in association with transient self-limited para-infectious anti-phospholipid antibodies. Comprehensive evaluation revealed no identifiable genetic prothrombotic variables. Both children recovered after receiving antibiotics and anticoagulation therapy. Thrombotic complications associated with Mycoplasma pneumoniae infections are rare, particularly in children; the occurrence of this complication in identical twins has not been previously reported.

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.

Detection of Mycoplasma pneumoniae in Mexican children with community-acquired pneumonia: experience in a tertiary care hospital

Purpose: Mycoplasma pneumoniae is an important cause of community-acquired pneumonia (CAP). Information on the prevalence of M. pneumoniae in pediatric patients with CAP in Mexico is limited. The aim of this study was to detect M. pneumoniae in hospitalized pediatric patients with CAP. Patients and methods: We performed a descriptive study in a tertiary-level pediatric reference center, obtaining 154 respiratory samples from patients under 18 years of age and diagnosed with CAP. M. pneumoniae was detected by real-time polymerase chain reaction (PCR) targeting the p1 and CARDS genes. Complete blood cell count, measurement of C-reactive protein and detection of IgM and IgG anti-P1 were performed. Clinical, epidemiological and radiological data of the patients were analyzed. Results: M. pneumoniae was detected by real-time PCR in 26.6% of the samples. 39% of the cases occurred during the spring season. A total of 83% of the patients with M. pneumoniae had some underlying disease; renal disease, autoimmune disease and primary immunodeficiencies had a significant association with M. pneumoniae CAP. Children under 6 years of age represented 53.7% of the cases. Fever and cough were the most frequent symptoms. IgM and IgG were positive in 1.9% and 14% of the patients, respectively. In the chest X-ray, 17.1% of the patients showed multifocal alveolar infiltrates pattern. The complications in this series were 26.8%. The mortality in this study was 4.9%. Conclusion: This is the first report in Mexico about M. pneumoniae as a causal agent of CAP in a tertiary care pediatric hospital using real-time PCR and serology. M. pneumoniae was responsible for 26.6% of the cases and was frequent in children under 6 years of age. In addition, we described the clinical presentation in patients with underlying diseases.

Stroke Associated With Recent Mycoplasma Pneumoniae Infection: A Systematic Review of Clinical Features and Presumed Pathophysiological Mechanisms

Introduction: An association between Mycoplasma pneumoniae (MP) infection and stroke has been described, especially in children. However, current knowledge on this rare potential cause of stroke is scant. The purpose of this systematic review of all published cases was to help better understand the relationships between recent MP infection and ischemic stroke on a clinical, radiological and pathophysiological perspective.

Material and Methods: A PubMed and Embase search was performed in September 2018 to identify all published cases of stroke occurring within 4 weeks after MP infection.

Results: Twenty-eight patients with ischemic stroke associated with MP infection were identified. Median age was 8 years (range: neonate to 57). The middle cerebral artery territory was involved in 25 (89%) patients. Fifteen (54%) patients had at least one arterial occlusion. Elevated D-dimer and/or fibrinogen was reported in 8 (29%) patients. Four patients had transient anticardiolipin IgM antibodies. Cerebrospinal fluid analysis showed pleocytosis in 7/20 (35%) patients (median: 19 leucocytes/μL, range: 10 to 63) and MP PCR was positive in 3/8 (38%) patients. The etiological work-up was considered inconclusive in 25 (89%) patients. Three (11%) patients died during follow-up, all of early respiratory deterioration. Neurological functional outcome was good in 22/27 (81%) patients.

Conclusion: The association between MP infection and ischemic stroke in children and young adults is rare. Underlying pathogenesis might include hypercoagulability and vasculitis. Most patients achieve a favorable recovery. Whether MP infection could be a long-term risk factor for stroke by promoting atherosclerosis is uncertain and deserves further investigation.