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Background: Mycoplasma pneumoniae pneumonia (MPP) is responsible for 20 to 40% of all cases of pneumonia acquired by children and shows an increasing incidence year by year. The aim of this study was to investigate the expression of miR-34a in children with MPP and its diagnostic value, and further explore the relationship between miR-34a and the rehabilitation effect of children with MPP., Methods: The expression level of miR-34a was detected by RT-qPCR, and the clinical value of miR-34a was analyzed by ROC analysis. In addition, the levels of IL-6, IL-18 and TNF-α in serum of children with MPP were detected by ELISA kit, and the correlation with miR-34a was analyzed., Results: Elevated levels of miR-34a were observed in the serum of children with MPP, and significantly higher expression levels were observed in children with severe symptoms and poor rehabilitation. The study suggested that miR-34a has potential as a diagnostic marker for MPP in children, helping to distinguish between mild and severe cases and predicting rehabilitation from MPP in children. In addition, miR-34a expression was positively correlated with IL-6, IL-8, and TNF-α levels., Conclusions: miR-34a is closely related to MPP in children and miR-34a may be used as a clinical biomarker for MPP in children., (© 2024. The Author(s).)

Background: Blood routine testing was the most commonly used laboratory method in clinical practice. The results are often influenced by factors such as instruments, reagents, and samples, among which, the interference of cold agglutinin is a very rare element. In our article, we reported a case of red blood cell agglutination caused by Mycoplasma pneumoniae infection., Methods: The number of blood cells were detected by blood routine analyzer with or without treatment at 37℃ water bath. The red blood cell agglutination was observed through blood smear staining. The cold agglutination test were performed using O-type red blood cells added into patient's plasma and refrigerated overnight at 4℃. We also used luminescent immunoassay technology to detect the content of MP antibodies in patient's serum., Results: The patient's results were RBC (2.69 x 1012/L), MCH (48.5 pg), MCHC (522 g/L). Through a microscope, we observed red blood cell agglutination. The concentration of MP-igM was 60.37 AU/mL. The cold agglutination test was positive. Following a 37℃ water bath, the patient's results changed: RBC (3.85 x 1012/L), MCH (31.2 pg), MCHC (352 g/L). The phenomenon of massive agglutination of red blood cells has also disappeared., Conclusions: The cold agglutinin produced by MP infection can alter the results of red blood cell. During the epidemic period of MP infection, it is important to pay attention to the phenomenon of abnormal elevation of MCHC in clinical practice.

Introduction. Recently, the incidence of Mycoplasma pneumoniae ( M. pneumoniae ) infection in children has been increasing annually. Early differential diagnosis of M. pneumoniae infection can not only avoid the abuse of antibiotics, but also is essential for early treatment and reduction of transmission. Gap statement. The change of routine blood parameters may have important clinical significance for the diagnosis of M. pneumoniae infection, but it has not been reported so far. Aim. This study aims to establish a predictive model for M. pneumoniae infection and explore the changes and clinical value of routine blood parameters in children with M. pneumoniae infection, serving as auxiliary indicators for the diagnosis and differentiation of clinical M. pneumoniae infection. Methodology. A total of 770 paediatric patients with respiratory tract infections were enrolled in this study, including 360 in the M. pneumoniae group, 40 in the SARS-CoV-2 group, 200 in the influenza A virus group, and 170 in the control group. The differences of routine blood parameters among all groups were compared, and risk factors were analysed using multivariate logistics analysis, and the diagnostic efficacy of differential indicators using ROC curves. Results. This study revealed that Mono% (OR: 3.411; 95% CI: 1.638-7.102; P =0.001) was independent risk factor associated with M. pneumoniae infection, and Mono% (AUC=0.786, the optimal cutoff at 7.8%) had a good discriminative ability between patients with M. pneumoniae infection and healthy individuals. Additionally, Mono% (OR: 0.424; 95% CI: 0.231-0.781; P =0.006) and Lymp% (OR: 0.430; 95% CI: 0.246-0.753; P =0.003) were independent risk factors for distinguishing M. pneumoniae infection from influenza A virus infection, and the Lymp% (AUC=0.786, the optimal cutoff at 22.1%) and Net% (AUC=0.761, the optimal cutoff at 65.2%) had good discriminative abilities between M. pneumoniae infection and influenza A infection. Furthermore, platelet distribution width (OR: 0.680; 95% CI: 0.538-0.858; P =0.001) was independent risk factor for distinguishing M. pneumoniae infection from SARS-CoV-2 infection. Meanwhile, the ROC curve demonstrated that PDW (AUC=0.786, the optimal cutoff at 15%) has a good ability to differentiate between M. pneumoniae infection and SARS-CoV-2 infection. Conclusion. This study demonstrates that routine blood parameters can be used as auxiliary diagnostic indicators for M. pneumoniae infection and provide reference for the diagnosis and differentiation of clinical M. pneumoniae infection.

To determine the clinical indicators predictive of refractory Mycoplasma pneumoniae pneumonia (RMPP) in children and develop a robust predictive model to aid in early identification and management. A retrospective cohort study was conducted on 338 children diagnosed with RMPP out of a total of 1500 cases of Mycoplasma pneumoniae at a single tertiary hospital from May 2021 to November 2023. Clinical and demographic data analyzed included age, gender, parents' educational level, household income, body mass index, allergic constitution, and laboratory findings such as white blood cell count, neutrophil and lymphocyte counts, platelet count, and levels of C-reactive protein (CRP), D-dimer, and procalcitonin. Univariate and multivariate logistic regression analyses were performed to identify significant predictors of RMPP, and a predictive model was developed. Among the RMPP cohort, 52.4% were female, with a mean age of 6.07 ± 2.78 years. Multivariate analysis identified several significant predictors of poor prognosis, including higher body mass index, longer duration of fever, elevated white blood cell count, neutrophil count, C-reactive protein levels, and increased neutrophil to lymphocyte ratio and platelet to lymphocyte ratio. The model demonstrated outstanding diagnostic performance, with an area under the receiver operating characteristic curve of 0.963 (95% confidence interval: 0.946-0.981). Our study identifies key clinical indicators with significant diagnostic accuracy for predicting RMPP in children. The predictive model established offers a valuable tool for clinicians, potentially improving RMPP outcomes through timely intervention., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Host-response biomarkers to differentiate bacterial from viral etiology in children with respiratory infections have shown high accuracies, but are understudied in Mycoplasma pneumoniae (Mp) infections., Methods: We compared BV scores (0-34 indicating viral etiology, and 66-100 indicating bacterial etiology), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL; pg/mL), interferon-γ inducible protein 10 (IP-10; pg/mL), and C-reactive protein (CRP; mg/L) serum levels between Mp-positive (Mp+) and Mp-negative (Mp-) community-acquired pneumonia (CAP) patients. We performed receiver operating characteristic (ROC) curve analyses for clinical features and biomarkers., Results: Of 80 CAP patients (median age, 6.3 years; 57.5% male), 26 had Mp+CAP. In Mp+CAP patients, compared to Mp-CAP patients, BV scores were lower (14.0 [3.0-27.8] vs 54.0 [12.0-84.8]; P = .0008), TRAIL levels were higher (86.5 [67.4-123.0] vs 65.5 [42.5-103.9]; P = .025), CRP levels were lower (12.9 [4.0-22.3] vs 36.7 [13.0-132.8]; P = .0019), and IP-10 levels were comparable (366.0 [150.2-603.8] vs 331.0 [154.3-878.8]; P = .73) (all median [interquartile range]). ROC analyses yielded a comparable discriminatory accuracy for the combination of age, fever duration, and duration of respiratory symptoms, with either procalcitonin or BV score (area under the ROC curve, 0.87 vs 0.86; P = .94)., Conclusions: Children with Mp+CAP have atypically low, viral levels of the BV score, underscoring the complementary role of microbiological testing., Competing Interests: Potential conflicts of interest . All authors: No reported conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: This study investigated clinical and laboratory characteristics of human bocavirus type 1 (HBoV1)-plastic bronchiolitis (PB), Mycoplasma pneumoniae (MP)-associated plastic bronchitis (PB) and MP-NPB in children, highlighting inflammation, coagulation, and bronchoscopic needs., Methods: Data on preschool children with PB during HBoV1 or MP infection were collected, comparing MP-PB to severe Mycoplasma pneumoniae pneumonia., Result: Compared with the MP-PB group, the HBoV1-PB group, with younger children, had significantly milder clinical symptoms but higher WBC counts (p = .028). The MP-PB group exhibited notably elevated Fibrinogen (p = .045) and d-dimer levels (p < .001). When contrasting the MP-PB with the MP-NPB group, children in MP-PB group still had higher levels of d-dimer and increased inflammatory indicators such as C-reactive protein, procalcitonin, lactate dehydrogenase, and interleukin-6, which were significantly elevated compared with the MP-NPB group. MP-PB showed a higher prevalence of plastic bronchial casts in lower lobes (p = .016) and a dominance of neutrophils in BALF cytology. Additionally, children in the MP-PB group tended to undergo a greater number of bronchoscopies., Conclusion: This study identifies key differences in plastic bronchitis in children due to HBoV1 and MP, highlighting HBoV1's milder inflammation in younger kids and MP's link to severe inflammatory and coagulation responses, guiding clinical diagnosis and treatment., (© 2024 The Author(s). Immunity, Inflammation and Disease published by John Wiley & Sons Ltd.)

Objectives: Influenza and Mycoplasma pneumoniae infections often present concurrent and overlapping symptoms in clinical manifestations, making it crucial to accurately differentiate between the two in clinical practice. Therefore, this study aims to explore the potential of using peripheral blood routine parameters to effectively distinguish between influenza and Mycoplasma pneumoniae infections., Methods: This study selected 209 influenza patients (IV group) and 214 Mycoplasma pneumoniae patients (MP group) from September 2023 to January 2024 at Nansha Division, the First Affiliated Hospital of Sun Yat-sen University. We conducted a routine blood-related index test on all research subjects to develop a diagnostic model. For normally distributed parameters, we used the T-test, and for non-normally distributed parameters, we used the Wilcoxon test., Results: Based on an area under the curve (AUC) threshold of ≥ 0.7, we selected indices such as Lym# (lymphocyte count), Eos# (eosinophil percentage), Mon% (monocyte percentage), PLT (platelet count), HFC# (high fluorescent cell count), and PLR (platelet to lymphocyte ratio) to construct the model. Based on these indicators, we constructed a diagnostic algorithm named IV@MP using the random forest method., Conclusions: The diagnostic algorithm demonstrated excellent diagnostic performance and was validated in a new population, with an AUC of 0.845. In addition, we developed a web tool to facilitate the diagnosis of influenza and Mycoplasma pneumoniae infections. The results of this study provide an effective tool for clinical practice, enabling physicians to accurately diagnose and differentiate between influenza and Mycoplasma pneumoniae infection, thereby offering patients more precise treatment plans., (© 2024. The Author(s).)

Background: The prevalence and severity of pediatric Mycoplasma pneumoniae pneumonia (MPP) poses a significant threat to the health and lives of children. In this study, we aim to systematically evaluate the value of routine blood parameters in predicting MPP and develop a robust and generalizable ensemble artificial intelligence (AI) model to assist in identifying patients with MPP., Methods: We collected 27 features, including routine blood parameters and hs-CRP levels, from patients admitted to The Affiliated Dazu's Hospital of Chongqing Medical University with or without MPP between January, 2023 and January, 2024. A classification model was built using seven machine learning (ML) algorithms to develop an integrated prediction tool for diagnosing MPP. It was evaluated on both an internal validation set (982 individuals) and an external validation set (195 individuals). The primary outcome measured the accuracy of the model in predicting MPP., Results: The GBDT is state-of-the-art based on 27 features. Following inter-laboratory cohort testing, the GBDT demonstrated an AUC, accuracy, specificity, sensitivity, PPV, NPV, and F1-score of 0.980 (0.938-0.995), 0.928 (0.796-0.970), 0.929 (0.717-1.000), 0.926 (0.889-0.956), 0.922 (0.727-1.000), 0.937 (0.884-0.963), and 0.923 (0.800-0.966) in stratified 10-fold cross-validation. A GBDT-based AI Lab was developed to facilitate the healthcare providers in remote and impoverished areas., Conclusions: The GBDT-based AI Lab tool, with high sensitivity and specificity, could help discriminate between pediatric MPP infection and non-MPP infection based on routine blood parameters. Moreover, a user-friendly webpage tool for AI Lab could facilitate healthcare providers in remote and impoverished areas where advanced technologies are not accessible., (© 2024. The Author(s).)

Objectives: To investigate the role of calprotectin S100 A8/A9 complex in evaluating the condition of children with severe Mycoplasma pneumoniae pneumonia (SMPP)., Methods: A prospective study was conducted among 136 children with Mycoplasma pneumoniae pneumonia (MPP) and 30 healthy controls. According to the severity of the condition, the children with MPP were divided into mild subgroup (40 children) and SMPP subgroup (96 children). The levels of S100 A8/A9 complex and related inflammatory factors were compared between the MPP group and the healthy control group, as well as between the two subgroups of MPP. The role of S100 A8/A9 in assessing the severity of MPP was explored., Results: The MPP group had a significantly higher level of S100 A8/A9 than the healthy control group, with a significantly greater increase in the SMPP subgroup ( P <0.05). The multivariate logistic regression analysis showed that the increases in serum C reactive protein (CRP) and S100A8/A9 were closely associated with SMPP ( P <0.05). The receiver operating characteristic (ROC) curve analysis showed that the combined measurement of serum S100 A8/A9 and CRP had an area under the ROC curve of 0.904 in predicting SMPP, which was significantly higher than the AUC of S100 A8/A9 or CRP alone ( P <0.05), with a specificity of 0.718 and a sensitivity of 0.952., Conclusions: S100 A8/A9 is closely associated with the severity of MPP, and the combination of S100 A8/A9 with CRP is more advantageous for assessing the severity of MPP in children.

Background: This study explored the relationship between inflammatory markers and glucocorticoid dosage upon admission., Methods: We conducted a retrospective analysis of 206 patients with refractory Mycoplasma pneumoniae pneumonia (RMPP) admitted to a Children's Hospital from November 2017 to January 2022. Patients were categorized into three groups based on their methylprednisolone dosage: low-dose (≤ 2 mg/kg/d), medium-dose (2-10 mg/kg/d), and high-dose (≥ 10 mg/kg/d). We compared demographic data, clinical manifestations, laboratory findings, and radiological outcomes. Spearman's rank correlation coefficient was used to assess relationships between variables., Results: The median age was highest in the low-dose group at 7 years, compared to 5.5 years in the medium-dose group and 6 years in the high-dose group (P < 0.001). The body mass index (BMI) was also highest in the low-dose group at 16.12, followed by 14.86 in the medium-dose group and 14.58 in the high-dose group (P < 0.001). More severe radiographic findings, longer hospital stays, and greater incidence of hypoxia were noted in the high-dose group (P < 0.05). Additionally, significant increases in white blood cells, C-reactive protein, procalcitonin, lactate dehydrogenase (LDH), alanine transaminase, aspartate transaminase, ferritin, erythrocyte sedimentation rate, and D-dimer levels were observed in the high-dose group (P < 0.05). Specifically, LDH and ferritin were markedly higher in the high-dose group, with levels at 660.5 U/L and 475.05 ng/mL, respectively, compared to 450 U/L and 151.4 ng/mL in the medium-dose group, and 316.5 U/L and 120.5 ng/mL in the low-dose group. Correlation analysis indicated that LDH and ferritin levels were significantly and positively correlated with glucocorticoid dose (Spearman ρ = 0.672 and ρ = 0.654, respectively; P < 0.001)., Conclusions: Serum LDH and ferritin levels may be useful biomarkers for determining the appropriate corticosteroid dosage in treating children with RMPP., (© 2024. The Author(s).)

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., (© 2024. The Author(s).)

This study aimed to investigate the expression and significance of serum procalcitonin (PCT), leukotriene B4 (LTB4), Serum amyloid A (SAA), and C-reactive protein (CRP) in children with different types of pneumonia caused by different pathogenic infections. One hundred and one children with pneumonia admitted to The Fifth People Hospital of Zhuhai from July 2019 to June 2020 were enrolled and divided into 38 cases in the bacterial group, 30 cases in the mycoplasma group, and 33 cases in the virus group according to the different types of pathogens. The patients were divided into 42 cases in the noncritical group, 33 cases in the critical group, and 26 cases in the very critical group according to the pediatric clinical illness score (PCIS), and 30 healthy children were selected as the control group during the same period. Comparison of serum PCT, SAA: bacterial group > mycoplasma group > viral group > control group with significant differences (P < .05). Receiver operator characteristic (ROC) analysis showed that the area under the curves (AUCs) of serum PCT, LTB4, SAA, and CRP for the diagnosis of bacterial pneumonia were 1.000, 0.531, 0.969, and 0.833, respectively, and the AUCs for the diagnosis of mycoplasma pneumonia were 0.653, 0.609, 0.547, and 0.652, respectively, and the AUCs for the diagnosis of viral pneumonia were 0.888, 0.570, 0.955, and 1.000, respectively. Comparison of serum PCT, LTB4, SAA: very critical group > critical group > noncritical group > control group, with significant differences (P < .05). Serum PCT, LTB4, and SAA were negatively correlated with PCIS score by Pearson analysis (P < .05). Serum PCT and SAA showed diagnostic value for bacterial pneumonia, and serum SAA and CRP showed diagnostic value for viral pneumonia; serum PCT, LTB4, and SAA correlate with severity of disease and show higher expression with worsening of the condition., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Mycoplasma pneumoniae necrotizing pneumonia (MPNP) has a long and severe disease course, which seriously threatens to jeopardize patients' lives and health. Early prediction is essential for good recovery and prognosis. In the present study, we retrospect 128 children with MPNP and 118 children with Mycoplasma pneumoniae pneumonia combined with pulmonary consolidation to explore the predictive value of lactate dehydrogenase (LDH) in children with MPNP by propensity score matching method, multiple logistic regression analysis, dose-response analysis and decision curve analysis. The WBC count, PLT count and percentage of neutrophils were significantly higher in necrosis group than consolidation group. The serum CRP, PCT, ESR, D-D, FIB, ALT, LDH, IgG and IgM were significantly higher in necrosis group. Compared to consolidation group, necrosis group is more severe in chest pain and dyspnea. Multivariate logistic regression analysis showed that duration of LDH levels, high fever, D-dimer, and fibrinogen were independent predictive factors for the incidence of MPNP. Restricted cubic spline analysis showed that a non-linear dose-response relationship between the continuous changes of LDH level and the incidence of MPNP. Decision curve analysis revealed that LDH had an important clinical value in predicting MPNP. This study provides a potential serologic indicator for early diagnosis of MPNP., (© 2024. The Author(s).)

Objective: Early diagnosis of Severity Mycoplasma Pneumoniae Pneumonia (SMPP) has been a worldwide concern in clinical practice. Two cytokines, soluble Triggering Receptor Expressed on Myeloid cells (sTREM-1) and Interferon-Inducible Protein-10 (IP-10), were proved to be implicated in bacterial infection diseases. However, the diagnostic value of sTREM-1 and IP-10 in MPP was poorly known. This study aimed to investigate the diagnostic value of sTREM-1 and IP-10 for SMPP., Methods: In this prospective study, the authors enrolled 44 children with MPP, along with their clinical information. Blood samples were collected, and cytokine levels of sTREM-1 and IP-10 were detected with ELISA assay., Results: Serum levels of sTREM-1 and IP-10 were positively correlated with the severity of MPP. In addition, sTREM-1 and IP-10 have significant potential in the diagnosis of SMPP with an Area Under Curve (AUC) of 0.8564 (p-value = 0.0001, 95% CI 0.7461 to 0.9668) and 0.8086 (p-value = 0.0002, 95% CI 0.6918 to 0.9254) respectively. Notably, the combined diagnostic value of sTREM-1 and IP-10 is up to 0.911 in children with SMPP (p-value < 0.001, 95% CI 0.830 to 0.993)., Conclusions: Serum cytokine levels of sTREM-1 and IP-10 have a great potential diagnostic value in children with SMPP., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 HCFMUSP. Published by Elsevier España, S.L.U. All rights reserved.)

To explore the clinical characteristics and changes in serum CXCL10 and CXCL16 in patients with severe mycoplasma pneumonia, and to analyze the risk factors of severe mycoplasma pneumonia. About 258 children with acute mycoplasma pneumoniae pneumonia (MPP) admitted to the respiratory department of a certain hospital from January 2020 to December 2022 were selected as the study subjects. According to the severity of MPP, patients are divided into 2 groups, namely the mild illness group (Q group) and the severe illness group (Z group). The number of cases in these 2 groups of children is 167 and 91, respectively. The serum CXCL10, CXCL16, and other indicators of 2 groups are tested. Compared to group Q, patients in group Z have a higher proportion of extrapulmonary complications, longer cough time, longer shortness of breath, and longer wheezing time (P < .05). The serum CXCL16 is higher and the proportion of pleural effusion is higher (P < .01). There are more cases of fever, longer fever duration, longer hospital stay, higher serum CXCL10, and higher D-dimer levels (P < .001). The area under the curve of the probability curve for predicting severe mycoplasma pneumonia is 0.975 (P < .05). Children with severe mycoplasma pneumonia have significantly longer fever duration and hospital stay than those with mild symptoms. The serum levels of CXCL10 and CXCL16 are significantly elevated., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: High uric acid levels are a risk factor for cardiovascular disorders, and metabolic diseases; however, the role of serum uric acid (sUA) during the mycoplasma pneumoniae pneumonia (MPP) of children is poorly known. This study aimed to clarify the effects of sUA during the MPP of children., Methods: This was a prospective cohort study of children with MPP from multi-center inpatient departments from September 2019 to August 2020. Routine laboratory characteristics analyzed including ALT, AST, BUN, CREA, UA, LDH, CK-MB, WBC, N%, PLT, and CRP. Subjects were divided into 3 groups: non-MPP, mild MPP (MMPP), and severe MPP (SMPP)., Results: 949 subjects were enrolled, including 207 in non-MPP, 565 in MMPP, and 177 in SMPP. The optimal cutoff value for sUA is 239 μmmol/L in receiver operating characteristic (ROC) curves analysis. Multivariate logistic regression showed that WBC and sUA had significance for protective effects between non-MPP and SMPP, but CRP did not have significance between the two groups, N and PLT had significance for risk factors; WBC and sUA did not have significance for the protective effects between non-MPP and MMPP, CRP had significance between the two groups, N and PLT had significance for the risk effects. Similarly, binary logistic regression showed UA, WBC, and CRP had significance for the protective effects between non-MPP and MPP, but N and PLT had significance for the risk effects between the two groups., Conclusion: Both multivariate and binary logistic regression demonstrated that sUA displayed a protective effect during the MPP of children, which meant sUA is anti-inflammatory., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

This study aimed to investigate the effect of erythromycin sequential therapy plus azithromycin on lung function and inflammatory factors in children with severe mycoplasma pneumonia (MP). Ninety-three severe MP children were selected and randomized into azithromycin group, erythromycin group, and combination group, 31 cases in each. The disappearance time of cough, fever, lung rale and X-ray shadow in the combination group were shorter than those in the azithromycin group and erythromycin group. The clinical treatment efficiency of the combination group was higher than that of the azithromycin group. After treatment, FVC, FEV1/FVC and PEF in combination group were higher than before treatment; IL-8, IL-6, CRP in combination group were lower than erythromycin group and azithromycin group. IL-8, IL-6, CRP are negatively correlated with disappearance time of cough, fever, pulmonary rale, X-ray shadow and clinical treatment efficiency; FEV1/FVC is positively correlated with disappearance time of cough and fever, pulmonary rales and X-ray shadow, and clinical treatment efficiency. Sequential erythromycin therapy combined with azithromycin in the treatment of MP can effectively inhibit high inflammatory reactions, control the disease in a timely manner, improve lung function and produce fewer adverse reactions.

Background: Mycoplasma pneumoniae ( M. pneumoniae ) is implicated in several immune-mediated extrapulmonary manifestations, including reactive arthritis. Recently, increased total serum IgE were reported in children developing M. pneumoniae -related extrapulmonary diseases (MpEPDs). Here, we aimed at analyzing these aspects in children affected with rheumatic disorders and, in detail, Juvenile Idiopathic Arthritis (JIA)., Methods: M. pneumoniae serology (IgG and IgM) and total serum IgE were concomitantly analyzed in 139 pediatric patients diagnosed with: JIA (Group 1, n = 85), or any rheumatic disease other than JIA (Group 2, n = 27), or non-inflammatory endocrinological disorders (Group 3, n = 27)., Results: Overall, 19.4% M. pneumoniae seroprevalence was observed in this hospitalized pediatric population, without signicant differences among the three groups. No significant differences in total serum IgE levels were noted among these groups; however, a second analysis excluding children with very high (and clearly abnormal) IgE levels suggested that JIA patients and, in detail, those with oligopolyarticular forms may have higher serum IgE concentrations. This relative difference among groups in serum IgE level seems to be more pronounced in M. pneumoniae seropositive children., Conclusions: M. pneumoniae infection should be actively sought in children developing immune-mediated diseases, including patients affected with JIA and, especially, in oligopolyarticular forms. There is some evidence that total serum IgE levels may tend to be increased in patients with oligopolyarticular JIA subtype and especially in those resulting as M. pneumoniae seropositive. However, further and focused research is needed to confirm these preliminary results and to clarify the relation between M. pneumoniae infection, atopic status, and immune-mediated arthritis., Competing Interests: The authors have no conflict of interest to declare., (Copyright © 2021 Dimitri Poddighe et al.)

Objective: To investigate the value of high-sensitivity C-reactive protein (hs-CRP) in evaluating the myocardial damage and prognosis in children with mycoplasmal pneumonia., Materials: A total of 150 children with mycoplasmal pneumonia were selected. According to their serum creatine kinase isoenzyme (CK-MB) level, they were divided into 72 cases of the myocardial damage group and 78 cases of the non-myocardial damage group. Eighty healthy children undergoing physical examination were selected as the control group. The electrocardiography results and serum CK-MB and hs-CRP levels were compared among the subjects. The correlations among the above indexes were analyzed., Results: The levels of hs-CRP and CK-MB in the myocardial damage group were significantly higher than those in the nonmyocardial damage group and control group, respectively ( P <0.05). The rates of abnormal hs-CRP and abnormal electrocardiogram in the myocardial damage group were significantly higher than those in the non-myocardial damage group, respectively ( P <0.05). In the 150 children with mycoplasmal pneumonia, the serum hs-CRP and CK-MB levels were positively correlated ( P <0.001), and the abnormal hs-CRP rate was positively correlated with the abnormal electrocardiogram rate ( P <0.001). In the myocardial damage group, the serum levels of hs-CRP and CK-MB after treatment were significantly lower than those before treatment, respectively ( P <0.05). After treatment, each index in the myocardial damage group had no significant difference with those in the control group ( P >0.05)., Conclusion: hs-CRP may be an important index for evaluating the myocardial damage and prognosis in children with mycoplasmal pneumonia. The combination of hs-CRP and CK-MB detection has obvious guiding significance for the monitoring and treatment of mycoplasmal pneumonia complicated by myocardial damage., (© 2021 by the Association of Clinical Scientists, Inc.)

Objective: Mycoplasma pneumoniae ( M. pneumoniae ), an extracellular pathogen lacking a cell wall, causes respiratory infection in adults and children and has been implicated in asthma exacerbation; immunoglobulin (Ig) E may be involved in these exacerbations. Specific IgM and IgG immune response to M. pneumoniae has been reported, but less is known about IgE M. pneumoniae antibody (Ab) responses in asthma. Previous studies in our laboratory demonstrated that asthmatic children have increased IgM M. pneumoniae levels, but not IgE. Thus, we sought to investigate whether past M. pneumoniae infection triggers production of M. pneumoniae -specific IgE Abs in adult subjects with/without asthma., Methods: M. pneumoniae - IgE and -IgM Ab responses were studied in adult asthmatic (N=22) and non-asthmatic (N=22) subjects (ELISA). Data are reported as antibody index. Threshold detection levels: IgE, IgM: 0.2, 0.9, respectively., Results: M. pneumoniae -IgE Ab levels were low and below the threshold of detection in both asthmatic and non-asthmatics (0.002 ± 0.008 vs. 0.02 ± 0.03; P =0.021). However, specific-IgM levels were slightly higher in non-asthmatics compared with asthmatics (0.96 ± 0.37 vs. 0.79 ± 0.31; P =0.054). M. pneumoniae -IgM Ab positivity was similar in both groups ( P =1.0)., Conclusion: IgM M. pneumoniae Abs may play an important role in non-asthma and persist for months after acute infection. IgE M. pneumoniae Abs may play a less important role in both groups., (© 2021 by the Association of Clinical Scientists, Inc.)

Objective: To identify patients with Mycoplasma pneumoniae pneumonia (MPP) with a risk of prolonged fever while on macrolides., Methods: A retrospective study was performed with 716 children admitted for MPP. Refractory MPP (RMPP-3) was defined as fever persisting for > 72 h without improvement in clinical and radiologic findings after macrolide antibiotics (RMPP-3) or when fever persisted for > 120 h (RMPP-5) without improvement in clinical and radiologic findings. Radiological data, laboratory data, and fever profiles were compared between the RMPP and non-RMPP groups. Fever profiles included the highest temperature, lowest temperature, and frequency of fever. Prediction models for RMPP were created using the logistic regression method and deep neural network. Their predictive values were compared using receiver operating characteristic curves., Results: Overall, 716 patients were randomly divided into two groups: training and test cohorts for both RMPP-3 and RMPP-5. For the prediction of RMPP-3, a conventional logistic model with radiologic grouping showed increased sensitivity (63.3%) than the model using laboratory values. Adding laboratory values in the prediction model using radiologic grouping did not contribute to a meaningful increase in sensitivity (64.6%). For the prediction of RMPP-5, laboratory values or radiologic grouping showed lower sensitivities ranging from 12.9 to 16.1%. However, prediction models using predefined fever profiles showed significantly increased sensitivity for predicting RMPP-5, and neural network models using 12 sequential fever data showed a greatly increased sensitivity (64.5%)., Conclusion: RMPP-5 could not be effectively predicted using initial laboratory and radiologic data, which were previously reported to be predictive. Further studies using advanced mathematical models, based on large-sized easily accessible clinical data, are anticipated for predicting RMPP.

Background: Identifying new molecular diagnostic markers for Mycoplasma Pneumoniae Pneumonia (MPP) has always been an essential topic since MPP cases have increased every year, especially among children. Here, we examined the correlation between serum level of Purinergic receptor P2X7, vitamin A, and 25-hydroxy vitamin D (25(OH)D) and the severity of MPP, aiming to identify molecules that have the potential to become diagnostic markers., Methods: This study was conducted on 186 cases aged 1-14 (136 MPP and 50 non-MPP patients). Serum levels of Purinergic receptor P2X7, vitamin A, 25(OH)D, and multiple inflammatory and immune factors were measured, compared, and tested for statistical significance., Results: Serum P2X7, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) levels were significantly increased in severe MPP patients, while serum vitamin A, 25(OH)D, IgA, and IgG levels were significantly decreased., Conclusion: Our results demonstrated a positive correlation between serum P2X7 level and the severity of MPP, and negative correlations between serum levels of vitamin A and 25(OH)D and the severity of MPP, suggesting that high serum levels of P2X7 and low serum levels of vitamin A and 25(OH)D may indicate relatively severer MPP., (© 2021 The Authors. Journal of Clinical Laboratory Analysis published by Wiley Periodicals LLC.)

Objective: Thise study is aimed to identify the biomarkers for predicting refractory Mycoplasma pneumoniae pneumonia in Chinese children at the time of the hospital admission., Methods: The case control study retrospectively analyzed the clinical characteristics and laboratory results of Chinese pediatric patients presenting with common and refractory Mycoplasma pneumoniae pneumonia (CMPP and RMPP). Overall, there were 216 cases in the CMPP group and 88 cases in the RMPP group. Venous blood was collected, and serum ferritin (SF), lactate dehydrogenase (LDH), D-dimer, C-reactive protein (CRP), procalcitonin (PCT), neutrophil count/lymphocyte count (NLR), and other indexes were measured. A single factor analysis, an ROC curve analysis, and a logistic regression analysis were used to determine the independent risk factors of RMPP and find combination of initial markers for RMPP., Results: There were significant differences between the RMPP group and the CMPP group in mean SF (529.82 [357.86] vs. 147.22 [122.68] ng/mL), LDH (522.08 [389.08] vs. 286.85 [101.02] U/L), D-dimer (6.65 [5.66] vs. 1.46 [2.45] μg/mL), CRP (62.80 [52.15] vs. 19.03 [24.50] mg/L), PCT (0.80 [2.61] vs. 0.16 [0.44]) ng/mL, and NLR (4.14 [2.52] vs. 2.62 [1.55]), with P < 0.05 for each comparison. ROC cut-off values of the above indexes were 329.01 ng/mL, 375.50 U/L, 2.10 μg/mL, 43.08 mg/L, 0.08 ng/mL, and 2.96, respectively. The logistic regression analysis showed that SF, D-dimer, and CRP are independent risk factors to predict RMPP., Conclusion: SF, D-dimer, and CRP are statistically significant biomarkers to predict RMPP in Chinese children patients in the settings of pediatric emergency department.

Background: Chlamydia pneumoniae and Mycoplasma pneumoniae have been implicated in the pathogenesis of asthma and are responsible for chronic inflammation when host immune system fails to eradicate the bacteria., Method: We performed a prospective study on 410 patients who underwent a visit at the asthma clinic of CHU of Liege between June 2016 and June 2018 with serology testing for C. pneumoniae and M. pneumoniae., Results: 65% of our asthmatic population had serum IgA and/or IgG towards C. pneumoniae, while only 12.6% had IgM and/or IgG against M. pneumoniae. Compared to seronegative asthmatics, asthmatics with IgA+ and IgG+ against C. pneumoniae were more often male and older with a higher proportion of patients with smoking history. They received higher doses of inhaled corticosteroids (ICS) and displayed lower FEV 1 /FVC ratio, higher RV/TLC ratio and lower conductance. They had higher levels of fibrinogen, though in the normal range and had lower sputum eosinophil counts. Patients with IgA- and IgG+ against C. pneumoniae were older and had higher blood monocyte counts and alpha-1-antitrypsin levels as compared to seronegative patients. Patients with IgM and/or IgG towards M. pneumoniae were more often males than seronegative asthmatics. In a subpopulation of 14 neutrophilic asthmatics with Chlamydia pneumoniae IgA + /IgG + treated with macrolides, we found a significant decrease in blood neutrophils and normalization of sputum neutrophil count but no effect on asthma quality of life and exacerbations., Conclusion: Positive Chlamydia serologic test is more common than positive Mycoplasma serology. Asthmatics with IgA and IgG against C. pneumoniae have more severe disease with increased airway obstruction, higher doses of ICS, more signs of air trapping and less type-2 inflammation.

Rationale: Cardiac thrombus and stroke are rare complications in Mycoplasma pneumoniae infection, which is a common cause of community-acquired pneumonia in children. Early detection and prevention of thrombus in children with M pneumoniae pneumonia is relatively difficult., Patient Concerns: A 5-year-old boy with severe M pneumoniae pneumonia was referred to our center. During the treatment with sufficient antibiotics, an echocardiography surprisingly revealed a thrombus in the left atrium, with significant changes in D-dimer level and anti-phospholipid antibodies. At day 12 after admission, the patient showed impaired consciousness, aphasia, and reduced limb muscle power. Magnetic resonance angiography (MRA) showed right middle cerebral artery infarction., Diagnoses: Cardiac thrombus and stroke associated with M pneumoniae pneumonia., Interventions: He was started on aggressive antibiotic therapy and urokinase thrombolytic therapy for 24 hours, continued with low molecular heparin calcium and aspirin along with rehabilitation training., Outcomes: On follow up, the D-dimer decreased slowly and echocardiograms showed a steadily decreasing size of thrombus with eventual disappearance at day 22 after admission. His left limb muscle power was improved after rehabilitation for 2 months., Lessons: Early diagnosis and treatment with multiple modalities maybe useful for improving prognosis of cardiac thrombus and stroke in M pneumoniae pneumonia. Changes in D-dimer level and anti-phospholipid antibodies should be routinely monitored in severe M pneumoniae pneumonia., Competing Interests: The authors have no conflicts of interests to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

There is limited data on serum biomarkers in distinguishing Mycoplasma pneumoniae (MP) from Streptococcus pneumoniae (SP) and viral pneumoniae (VP) etiologies of community-acquired pneumonia (CAP). A retrospective study of inpatients diagnosed with CAP at the First Affiliated Hospital of Dali University (Dali, Yunnan, China) between January 2018 and June 2020 was conducted. The demographic, clinical and laboratory data of the patients with CAP were analyzed. Univariate analyses identified predictors for MP infections. The discriminative power of C-reactive protein (CRP), procalcitonin (PCT), CRP/PCT and CRP/PCT >350 μg/ng was assessed by area under the curve (AUC) of the receiver operating characteristic (ROC) curves. A total of 552 CAP patients, including 247 (44.7%) with MP, 152 (27.6%) with SP and 153 (27.7%) with influenza A and B viruses, were enrolled. When comparing MP with SP, cough and CRP/PCT >350 μg/ng (odds ratio [OR]) 2.88, p  < .001) were predictors for MP. CRP/PCT >350 μg/ng had 76% sensitivity and 100% specificity (AUC = 0.89, p  < .001, 95% confidence interval [CI]:0.81-0.94) to predict MP infections. Furthermore, similar results were again obtained when comparing MP with VP. CRP/PCT >350 μg/ng present better information (OR: 4.70; AUC = 0.92, p  < .001, 87% sensitivity and 100% specificity). In addition, comparing MP and non-MP (SP and VP combined), CRP/PCT >350 μg/ng exhibited excellent performance (AUC = 0.90, 95%CI 0.83-0.95, p  < .001, 76% sensitivity and 100% specificity). CRP/PCT ratio may be a potential index to distinguish MP-CAP from non-MP-CAP.

The correct diagnosis of acute infections as to bacteria, mycoplasma or virus is a clinical challenge and has a great impact on the therapeutic decisions. Current diagnostic tests of mycoplasma pneumoniae infections of the respiratory tract such as PCR and serology are either somewhat unreliable or slow and do not entirely meet the clinical needs of accurate and fast diagnosis. The aim of this report was to examine a panel of candidate biomarkers and their capacity to distinguish mycoplasma pneumoniae respiratory infections from respiratory infections caused by either bacterial or virus., Method: Patients with confirmed etiology of their acute respiratory infections (n = 156) were included of which 28 patients were diagnosed with mycoplasma pneumoniae. Blood was taken before any antibiotics treatment and analysed for Azurocidin (HBP), Calprotectin, CRP, Human Neutrophil Lipocalin (HNL), Interferon γ-induced Protein 10 kDa (IP-10), Procalcitonin (PCT), Thymidine Kinase 1 (TK1), TNF-Related Apoptosis-Inducing Ligand (TRAIL)., Results: Individually the concentrations of IP-10, TK1 and P-HNL distinguished mycoplasma pneumoniae from bacterial infections with AUCs of 0.79-0.85. However, in combination, TK1 with either IP-10 or P-HNL showed an AUC of 0.97-0.95. In the distinction between mycoplasma pneumoniae and viral respiratory infections CRP, Calprotectin and TRAIL showed individual AUCs of 0.94-0.84. Together with either P-HNL dimer or PCT, CRP showed AUCs of 0.97., Conclusion: Our results indicate that it may be possible to design useful diagnostic algorithms of biomarkers that could help distinguish mycoplasma pneumoniae from respiratory infections caused by bacteria or virus. The development of rapid point-of-care assays based on such algorithms could be clinically useful tools in the therapeutic decision-making., (Copyright © 2020 The Authors. Published by Elsevier B.V. All rights reserved.)

Abstract: 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., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2021 the Author(s). Published by Wolters Kluwer Health, Inc.)

To investigate the relationships between LncRNA NNT-AS1, CRP, PCT and their interactions and the refractory mycoplasma pneumoniae pneumonia (RMPP) in children. Serum levels of LncRNA NNT-AS1 of RMPP and non-RMPP (NRMPP) patients were detected by real-time PCR, and were analyzed together with serum c-reactive protein (CRP) and procalcitonin (PCT). Correlations between LncRNA NNT-AS1 and CRP and PCT were analyzed by Pearson correlation test. The ROC curve was used to analyze the potential of LncRNA NNT-AS1, CRP and PCT as biomarkers for predicting RMPP. Logistic regression crossover model and the Excel compiled by Andersson et al. were used to analyze the interactions among the biomarkers. We found that LncRNA NNT-AS1, CRP and PCT were all highly expressed in patients with RMPP. LncRNA NNT-AS1 could positively correlate with the expressions of CRP and PCT, and jointly promote the occurrence of RMPP. The combined diagnosis of LncRNA NNT-AS1, CRP and PCT could predict the occurrence of RMPP.

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.

BACKGROUND This retrospective study aimed to investigate co-infections with common respiratory pathogens and SARS-CoV-2 and laboratory biochemistry findings in patients with COVID-19 in the Zhuzhou area of China, in order to provide a reference for the disease assessment and clinical treatment of COVID-19. MATERIAL AND METHODS The clinical data of COVID-19 patients admitted to the hospital of Zhuzhou City from January 28 to March 15, 2020, as well as laboratory test results for respiratory pathogens and biochemical indicators, were collected to conduct correlation analyses. All patients were diagnosed based on fluorescence-based PCR assay for SARS-CoV-2. RESULTS Eleven of the 78 patients (14.1%) were co-infected with other respiratory pathogens, among which Mycoplasma pneumoniae (n=5, 45.5%) and respiratory syncytial virus (n=4, 36.4%) were the most frequent. There were 8 patients co-infected with 1 other pathogen and 3 patients co-infected with 2 other pathogens. Compared with mono-infected COVID-19 patients, patients with co-infections had significantly higher levels of procalcitonin (P=0.002). CONCLUSIONS The findings showed that Mycoplasma pneumonia and respiratory syncytial virus were the most common co-infections in patients with COVID-19 pneumonia. Increased levels of PCT in patients with COVID-19 pneumonia were associated with co-infection.

Mycoplasma pneumoniae is a bacterial human pathogen that causes primary atypical pneumonia. M. pneumoniae motility and infectivity are mediated by the immunodominant proteins P1 and P40/P90, which form a transmembrane adhesion complex. Here we report the structure of P1, determined by X-ray crystallography and cryo-electron microscopy, and the X-ray structure of P40/P90. Contrary to what had been suggested, the binding site for sialic acid was found in P40/P90 and not in P1. Genetic and clinical variability concentrates on the N-terminal domain surfaces of P1 and P40/P90. Polyclonal antibodies generated against the mostly conserved C-terminal domain of P1 inhibited adhesion of M. pneumoniae, and serology assays with sera from infected patients were positive when tested against this C-terminal domain. P40/P90 also showed strong reactivity against human infected sera. The architectural elements determined for P1 and P40/P90 open new possibilities in vaccine development against M. pneumoniae infections.

Mycoplasma pneumoniae infection is frequent but generally mild or self-limiting. Approximately 10% of cases develop clinical signs of pneumonia with "atypical" radiographic pattern. However, mycoplasma pneumoniae can be responsible for a variety of extrapulmonary manifestations, potentially involving all systems and apparatuses. Although exact pathophysiological mechanisms are not completely known, these could be secondary to direct invasion of the target organ, immunological damage due to molecular mimicry or vascular obstruction. A 45-year-old man was admitted to Internal Medicine Unit because of fever, dry cough and fatigue lasting 15 days. Fever disappeared after starting clarithromycin. About 72 h after admission the patient complained of right calf pain and tachypnea. The presence of anti-mycoplasma antibodies suggested mycoplasma pneumoniae infection. Moreover, a diagnosis of venous thrombo-embolism was performed. Given the absence of classical risk factors for thrombosis, patient was investigated for inherited and acquired thrombophilia and tested positive for antiphospholipid antibodies. A review of the English literature on the association between m. pneumoniae and pulmonary embolism will be provided in order to underline the possible pathogenetic role of antiphospholipid antibodies in this setting. Clinicians should outweigh risk and benefits for LMWH prophylaxis case by case considering these adjunctive pro-thrombotic mechanisms in patients m. pneumoniae infection.

Background: To analyze the clinical characteristics of Mycoplasma pneumoniae pneumonia with hypoxia in children, and identify the associated risk factors of hypoxia in MPP., Methods: A retrospective case-control study was performed on 345 children with Mycoplasma pneumoniae pneumonia (MPP) admitted to our hospital wards from January 2017 to June 2019. They were divided into three groups, namely MPP with hypoxia, refractory Mycoplasma pneumoniae pneumonia (RMPP), and general Mycoplasma pneumoniae pneumonia (GMPP). The clinical features, laboratory findings, imaging, and management were collected and compared in the three groups., Results: The MPP with hypoxia patients (n = 69) had longer disease duration, a higher extra-pulmonary complications rate, and more severe radiological abnormalities (P < 0.05). They also needed more complicated treatments (P < 0.05). Meanwhile, the levels of white blood cell count (WBC), C-reactive protein (CRP), lactic dehydrogenase (LDH), interleukin (IL)-6, ferritin, D-dimer, fibrinogen (FG), alanine aminotransferase (ALT) and the percentage of neutrophils in the MPP with hypoxia group were significantly higher than those in the RMPP group and the GMPP group (P < 0.05). In ROC curve analysis, the percentage of neutrophils, WBC, CRP, LDH, IL-6, ferritin, D-dimer, and ALT were contributed to identify the MPP with hypoxia patients. Multivariate logistic regression analysis revealed that ferritin> 174.15 ng/mL, IL-6 > 25.475 pg/ml, and pleural effusion were significantly associated with the incidence of hypoxia in MPP (P < 0.01)., Conclusion: MPP with hypoxia patients presented more serious clinical manifestations. Ferritin> 174.15 ng/mL, IL-6 > 25.475 pg/ml and pleural effusion were related risk factors for hypoxia in MPP.

Introduction: Mycoplasma pneumoniae (Mypn) infection could be occurring at an earlier age due to social pheno mena such as attending daycare centers more frequently and earlier than decades ago., Objective: to estimate the prevalence of anti-Mypn antibodies in children aged 0-12 years, and to explore whether age, attendance to daycare center/school, overcrowding or the presence of children aged below 12 years in the households increase the risk of seropositivity., Patients and Method: Cross-sectional stu dy including healthy children aged 0-12 years which required blood draws for routine laboratory tests. In all cases, the aforementioned variables were recorded and anti-Mypn IgG was determined by enzyme immunoassay. The association between predictors and seropositivity was assessed in a logistic regression model., Results: We included 232 patients (average age 56.4 ± 40.0 months). 56.9% attended a daycare center/school, 63.8% co-habited with children under 12 years old, and 15.9% lived in overcrowded households. The prevalence of anti-Mypn antibodies was 14.6%. There were no significant differences between seropositive and seronegative children regarding age (63.1 ± 40.7 vs. 55.4 ± 41.3 months), school/day-care attendance (64.7% vs. 55.5%), overcrowding (14.7% vs. 14.9%), or co-habiting with children (64.7% vs. 63.6%). Age was not an independent predictor of seropositivity in the multivariate model., Conclusion: The prevalence of anti-Mypn antibodies in children was 14.6% and age was not a predictor of seropositivity.

This study aimed to investigate the inner linkage and mechanism of Mycoplasma pneumoniae (MP) infection and Kawasaki disease (KD), as well as the risk factors of outcome in this cohort of patients.A retrospective study was performed in 210 patients diagnosed with KD complicated with community acquired pneumonia (CAP) in Children's Hospital, Zhejiang University School of Medicine from January 2014 to December 2017. They were divided into two groups based on MP infection: MP infection group (n = 97) and non-MP infection group (n = 113). We compared the variables of these two groups based on medical records.The MP infection group had higher ESR than the non-MP infection group. During hospitalization, the non-MP infection group had higher levels of WBC during hospital, LDH, PCT, and lower HB when compared to the MP infection group. No differences were found in the hs-CRP level, N%, PLT, ALT, CKMB, and cytokine levels (IL-2, IL-4, IL-6, IL-10, TNF-α, and IFN-γ) between MP and non-MP infection group. Likewise, no difference was found in fever duration or hospital stays between them. Totally 19 patients in the infection group had CAA with a rate of 19.59%; and 27 (23.89%) patients had CAA in the non-MP infection group. Unfortunately, no difference was found in CAA rate between the two groups.MP infection may occur simultaneously in children with Kawasaki disease. KD patients with MP infection tended to occur in older population. MP infection may not increase the risk of CAA, which still needs further large-scaled studies to confirm. Clinicians should be alert to KD patients with high level of ESR. MP should be screened and early treatment with macrolides should be given timely.

Mycoplasma pneumoniae (MP) is one of the most common pathogens of respiratory infection in children, while Epstein-Barr virus (EBV) infection is usually subclinical in immunocompetent children. Although single MP infection is common enough, MP and EBV coinfection have received little attention. Especially, the pathogenic role of EBV in lung when coinfection with MP, has not been clarified. The purpose of this study was to investigate the impact of EBV on MP pneumonia (MPP) in hospitalized children. We retrospectively reviewed the clinical data of MPP children who underwent screening for EBV by polymerase chain reaction in bronchoalveolar lavage fluid during hospitalization in 2014. Of total 147 patients, 68 patients were in the MP group and 79 were in the MP/EBV coinfection group. We found longer fever duration and higher CRP, IgA, IgG, interleukin-2 (IL-2), percentage of peripheral neutrophils levels, higher incidence of pulmonary consolidation and percentage of refractory MPP in coinfection group, when compared to those in MP group. In ROC curve analysis, IL-2 was useful for differentiating patients with coinfection from those with MP infection. Logistic regression analysis showed that the IL-2 ≥ 3.35 pg/ml (OR = 3.677) was a significant predictor regarding to MP/EBV coinfection. In conclusion, coinfection of EBV and MP poses a higher risk for prolonged symptoms. IL-2 could be used as a good predictor of coinfection.

Respiratory tract infections require early diagnosis and adequate treatment. With the antibiotic overuse and increment in antibiotic resistance there is an increased need to accurately distinguish between bacterial and viral infections. We investigated the diagnostic performance of calprotectin in respiratory tract infections and compared it with the performance of heparin binding protein (HBP) and procalcitonin (PCT). Biomarkers were analyzed in patients with viral respiratory infections and patients with bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis (n = 135). Results were compared with values obtained from 144 healthy controls. All biomarkers were elevated in bacterial and viral infections compared to healthy controls. Calprotectin was significantly increased in patients with bacterial infections; bacterial pneumonia, mycoplasma pneumonia and streptococcal tonsillitis compared with viral infections. PCT was significantly elevated in patients with bacterial pneumonia compared to viral infections but not in streptococcal tonsillitis or mycoplasma caused infections. HBP was not able to distinguish between bacterial and viral causes of infections. The overall clinical performance of calprotectin in the distinction between bacterial and viral respiratory infections, including mycoplasma was greater than performance of PCT and HBP. Rapid determination of calprotectin may improve the management of respiratory tract infections and allow more precise diagnosis and selective use of antibiotics.

Background: Different from the diagnosis of bacterial infections, Mycoplasma pneumoniae pneumonia (MPP) is still lacking of convenient non-specific laboratory parameters., Method: A total of 125 children with MPP were included in the MPP group and 89 children with Mycoplasma-negative pneumonia were included in the control group, and the sera were collected from the children at both the acute and recovery stages in the two groups., Results: The sialic acid and C3 in the MPP group were significantly higher than those in the control group both at the acute and at the recovery stage. On the other hand, the sialic acid and C3 at the acute stage were significantly higher than those at the recovery stage in the MPP group. However, in the control group, the sialic acid and C3 demonstrated IgG exhibited no significant change between the acute stage and the recovery stage. Lastly, positive correlations between sialic acid level and C3 level were identified in the MPP group at both acute and recovery stages., Conclusion: Our study demonstrated that the serum sialic acid correlated with C3 specifically increased in children with MPP, indicating that it might be the important non-specific parameters in the diagnosis of MPP., (© 2020 The Authors. Journal of Clinical Laboratory Analysis Published by Wiley Periodicals, Inc.)

Objective: To explore the relationship between serum sB7-H3 and cytokines (TNF-α, IL-1β and IL-6) and to evaluate the development of Mycoplasma pneumonae pneumonia (MPP) through analysis of the expression levels of above indices in serum of children with MPP., Study Design: An experimental study., Place and Duration of Study: Department of Clinical Laboratory, Renmin Hospital of Wuhan University, China, from January 2018 to August 2019., Methodology: One hundred and eight children with MPP were divided into severe MPP group (53 cases) and mild MPP group (55 cases) according to children's condition. Fifty children who received hernia or selective operation due to redundant prepuce were included in control group. Serum sB7-H3, TNF-α, IL-1β and IL-6 were compared., Results: Serum sB7-H3, TNF-α, IL-1β, and IL-6 levels in MPP group were higher than those in control group (all p<0.001); above indices in severe MPP group were higher than those in mild MPP group (all p<0.001). Pearson's linear correlation analysis results revealed that sB7-H3 had positive correlation with TNF-α, IL-1β, and IL-6 in MPP group (r=0.986, p<0.001; r=0.987, p<0.001; and r=0.991, p<0.001, respectively)., Conclusion: Detection of SB7-H3, TNF-α, IL-1β and IL-6 levels may be conducive to early diagnosis of MPP and the judgement of the severity of this disease.

Background: Extensive studies have focused on the diagnosis and treatment of Mycoplasma pneumoniae infection; however, rare studies investigated the posttreatment conditions. We analyzed the carrying status of M. pneumoniae in the respiratory tract of children before and after treatment., Methods: Ninety-two children with M. pneumoniae pneumonia were included in this study. Clinical data were obtained from each patient, and pharyngeal swab sampling was performed at preliminary diagnosis and discharge. Real-time PCR and dilution quantitative culture were utilized to determine the DNA quantification and number of viable M. pneumoniae from samples collected upon preliminary diagnosis and discharge., Results: All the 92 cases showed DNA positivity upon preliminary diagnosis, serum IgM antibody was detected in 80 patients, and positivity of M. pneumoniae culture was observed in 82 cases. Upon discharge, the M. pneumoniae nucleotide and culture positivity were detected in 87 and 49 cases, respectively. The content of viable M. pneumoniae was 10-10 4  CCU/mL and 10-10 2  CCU/mL in the preliminary diagnosis samples and discharge samples, respectively., Conclusions: Real-time PCR was rapid and effective for the qualitative diagnosis of M. pneumoniae at the early stage, but it cannot be used to evaluate the prognosis of patients with M. pneumoniae infection. Quantitative analysis for M. pneumoniae DNA could not directly reflex the viable strain content., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Fei Zhao et al.)

Objectives: Mycoplasma pneumoniae is a leading cause of community-acquired pneumonia in children. However, its mechanism of pathogenesis is not fully understood, and microRNAs might play a role. This study aimed to explore the microRNA-222-3p (miR-222-3p) expression and its possible role in children with M.pneumoniae pneumonia (MPP)., Methods: Thirty-six children with MPP and twenty-seven age-matched controls from Children's Hospital of Soochow University were enrolled in this study. MiR-222-3p and cluster of differentiation 4 (CD4) mRNA were detected using real-time PCR in children's peripheral blood plasma samples. THP-1 cells and mice were stimulated with M.pneumoniae lipid-associated membrane proteins(LAMPs)., Results: Children with MPP had significantly higher levels of miR-222-3p and lower levels of CD4 in peripheral blood plasma (P <  0.05). Additionally, Sixteen children with MPP complicated with pleural effusion had higher miR-222-3p levels than those without pleural effusion. MiR-222-3p or CD4 in THP-1 cells increased or decreased, respectively, in a dose dependent manner after LAMP stimulation. In LAMP-stimulated mice massive inflammatory cells infiltrates surrounded the bronchioles, and miR-222-3p increased in the bronchoalveolar lavage fluid. In conclusion, miR-222-3p was highly expressed in children with MPP, especially those with pleural effusion., Conclusion: Small sample studies showed that M.pneumoniae or its LAMPs could increase miR-222-3p and decrease CD4 in macrophages,both in vitro and vivo.Thus, miR-222-3p might be an MPP biomarker for the diagnosis and prognosis.

Using the hospital records, we retrospectively assessed whether urinary β2 microglobulin/creatinine ratio (UBCR) and lactate dehydrogenase (LD) values could be used to estimate the severity of Mycoplasma pneumoniae-associated lower respiratory tract infection (MP-LRTI). We studied 48 patients with MP-LRTI (median age, 7.5 years; range, 3-14 years) admitted to Kagoshima City Hospital and examined the relationships of the UBCR or LD values with fever and pulmonary tissue damage (hypoxemia and severity assessments on chest radiographs). Patients were assigned to four groups based on whether they had fever and/or hypoxemia. Patients with high fever showed significantly higher UBCR values than those without (P < 0.05), whereas those with hypoxemia showed higher LD values than those without (P = 0.001). The maximum body temperature on admission was closely associated with the UBCR but not with LD levels. In chest radiography assessments, LD levels were significantly higher in patients with severe than mild or moderate MP-LRTI. A cut-off LD level of 530 IU/L showed a very high sensitivity (100%) and specificity (93%). Although UBCR values were higher in patients with severe MP-LRTI, the differences were not statistically significant. Our study shows that the UBCR is associated with body temperature, whereas LD levels may serve as an index of pulmonary tissue damage in children with MP-LRTI., (Copyright © 2019 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

We report the first paediatric case of splenic infarction following acute Mycoplasma pneumoniae infection with induction of anti-prothrombin (aPT) antibodies. A 12-year-old boy was admitted to the paediatric emergency department for a left pleuropneumonia and a splenic infarction. aPT antibodies were transitorily detected. The patient recovered fully after antibiotic therapy and a 3-month course of anticoagulation treatment. Antiphospholipid (aPL) antibodies induced by acute infections have already been reported but cases of clinically relevant thrombosis remain rare. The pathogenicity of aPT antibodies is discussed here. We hypothesize that these antibodies were involved in this symptomatic hypercoagulable state., (Copyright © 2019. Published by Elsevier Masson SAS.)

The aim of this study was to evaluate the changes in the three subsets of monocyte (classical, intermediate, and non-classical) and the expression of human leukocyte antigen-DR (HLA-DR) on monocyte subsets during MP pneumonia in children. Monocyte subsets were analyzed in the peripheral blood of healthy volunteers and MP pneumonia patients at the stages of admission and remission after clinical therapy. They were defined as classical (CD14 + CD16 - ), intermediate (CD14 bright CD16 + ), and non-classical (CD14 dim CD16 + ) using flow cytometry. Furthermore, three subsets of monocyte were analyzed for the expression of HLA-DR. Patients with MP pneumonia at admission had a higher proportion of intermediate and non-classical monocytes than healthy subjects (all P < 0.05). The proportion of intermediate subset and non-classical subset was lower in MP pneumonia patients at remission than at admission (all P < 0.05). In comparison with the other monocyte subsets, intermediate subset showed a significantly higher percentage of HLA-DR in MP pneumonia patients at admission (P < 0.05). Further analysis revealed that the expression of HLA-DR on intermediate subset was lower in severe patients than in non-severe patients (P < 0.05).Our data has shown for the first time that MP pneumonia is associated with the increased proportion of non-classical and intermediate monocytes, indicating the involvement of monocyte-related mechanisms in the pathogenesis of this disease. Additionally, the decreased expression of HLA-DR on CD14 bright CD16 + subset may be a potential indicator of the severity of MP pneumonia.

Background Discriminating Mycoplasma pneumoniae (MP) from Streptococcus pneumoniae (SP) and viral etiologies of community-acquired pneumonia (CAP) is challenging but has important implications regarding empiric antibiotic therapy. We investigated patient parameters upon hospital admission to predict MP infection. Methods All patients hospitalized in a tertiary care hospital between 2013 and 2017 for CAP with a confirmed etiology were analyzed using logistic regression analyses and area under the receiver operator characteristics (ROC) curves (AUC) for associations between demographic, clinical and laboratory features and the causative pathogen. Results We analyzed 568 patients with CAP, including 47 (8%) with MP; 152 (27%) with SP and 369 (65%) with influenza or other viruses. Comparing MP and SP by multivariate logistic regression analysis, younger age (odds ration [OR] 0.56 per 10 years, 95% CI 0.42-0.73), a lower neutrophil/lymphocyte ratio (OR 0.9, 0.82-0.99) and an elevated C-reactive protein/procalcitonin (CRP/PCT) ratio (OR 15.04 [5.23-43.26] for a 400 mg/μg cut-off) independently predicted MP. With a ROC curve AUC of 0.91 (0.80 for the >400 mg/μg cutoff), the CRP/PCT ratio was the strongest predictor of MP vs. SP. The discriminatory value resulted from significantly lower PCT values (p < 0.001) for MP, while CRP was high in both groups (p = 0.057). Comparing MP and viral infections showed similar results with again the CRP/PCT ratio providing the best information (AUC 0.83; OR 5.55 for the >400 mg/μg cutoff, 2.26-13.64). Conclusions In patients hospitalized with CAP, a high admission CRP/PCT ratio predicts M. pneumoniae infection and may improve empiric management.

We report the case of a 9 year-old boy, presenting with an acute encephalitis with cerebrospinal fluid pleiocytosis. MRI showed T2/FLAIR (fluid attenuated inversion recovery) hyperintense signals of basal ganglia and cortex, EEG (electro encephalogram) showed diffuse slowing with epileptic discharges. A repetitively elevated IgM/IgG serologic response against Mycoplasma pneumoniae was observed with polymerase chain reaction in serum and cerebrospinal fluid remaining negative. No other pathogen or antigen could be identified. High IgG and IgM levels against the glycolipid galactocerebroside were detected in serum but not in CSF. After treatment with corticosteroids, the patient fully recovered. Brain MRI and EEG investigation returned completely normal. Besides a primary infection of the central nervous system, M. pneumoniae is associated with a parainfectious encephalitis in children which may be mediated by antibodies to galactocerebroside., Competing Interests: Dr. B.C.J. reports grants from Baxalta, grants from Grifols, grants from CSL-Behring, grants from Annexon, grants from Prinses-Beatrix Spierfonds, grants from GBS-CIDP Foundation International, outside the submitted work. All the other authors report no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

Purpose: Respiratory tract infections are a major cause of global morbidity and mortality. Pneumonia is the ninth leading cause of mortality in Sri Lanka. Atypical pathogens cause about one-fifth of community-acquired pneumonia, while Mycoplasma pneumoniae accounts for about 50 %. This study aimed to determine the seroprevalence of M. pneumoniae respiratory tract infections in Sri Lanka while attempting to understand the relationships between the serology and PCR., Methodology: Paired sera from 418 adult patients (pneumonia, n=97; bronchitis, n=183; pharyngitis, n=138) and 87 healthy controls were studied. IgM, IgG and IgA antibodies were tested by M. pneumoniae enzyme-linked immunosorbent assay (ELISA). Positive IgM and or IgG seroconversion was considered to be seropositive. M. pneumoniae DNA were tested by PCR in age and gender-matched seropositives and seronegatives., Results: M. pneumoniae IgG was in 14.4 % (14/97), 6.0 % (11/183) and 1.5 % (2/138) of pneumonia, bronchitis and pharyngitis patients, respectively, whilst IgM was in 6.2 % (6/97), 1.1 % (2/183) and 0 % (0/138), respectively. Amongst the pneumonia seropositives, 64.7 % (11/17) showed IgG alone, 17.5 % (3/17) showed IgM alone and 17.5 % (3/17) showed IgM and IgG. Amongst the bronchitis seropositives, 84.6 % (11/13) had IgG alone and 15.4 % (2/13) had IgM alone. In the pharyngitis seropositives, only IgG was detected 100 % (2/2). M. pneumoniae DNA was in 52.2 % (12/23) of seropositives and 15.4 % (4/26) of seronegatives. In pneumonia or bronchitis patients, specific DNA was in 77.8 % (7/10) and 50 % (6/12) of patients, respectively. M. pneumoniae DNA was not found in pharyngitis patients. Of the seropositive PCR-negative pneumonia patients, 66.7 % (2/3) showed IgG alone and 33.3 % (1/3)showed IgM alone. In bronchitis patients, 83.3 % (5/6) showed IgG alone and 16.7 % (1/6) showed IgM alone. Of the seronegative PCR-positive patients, 16.7 % (2/12) had pneumonia and 18.2 % (2/11) had bronchitis., Conclusion: The serological evidence for M. pneumoniae infection in Sri Lanka comprised the following prevalences: 17.5 % (17/97), 7.1 % (13/183) and 1.4 % (2/138) in adults with pneumonia, bronchitis or pharyngitis, respectively. M. pneumoniae DNA was in 52.2 % (12/23) of seropositives and 15.4 % (4/26) of seronegatives. IgG was predominant in PCR positives and negatives.