Constrictive pericarditis secondary to infection with Mycoplasma pneumoniae

Predicting myocardial damage in children with mycoplasma pneumoniae pneumonia: a retrospective case-control study

PURPOSE

To investigate the clinical indicators that can predict myocardial damage in children with mycoplasma pneumoniae pneumonia (MPP) to help early identification and management.

METHODS

The clinical data of 123 MPP children admitted from December 2023 to February 2024 in the affiliated Changzhou Children's Hospital of Nantong University were analyzed retrospectively. According to the creatine kinase isoenzyme (CK-MB) level, the children were divided into 61 cases without myocardial damage group and 62 cases with myocardial damage group. Clinical manifestations and laboratory parameters were compared between the two groups. The factors affecting myocardial damage in children with MPP were analyzed by logistic regression. The ROC curve analyzed the predictive value of relevant indicators for myocardial damage in children with MPP.

RESULTS

The incidence of abnormal electrocardiogram (ECG), extrapulmonary manifestations (except myocardial damage), white blood cell count (WBC), neutrophil/lymphocyte ratio (NLR), erythrocyte sedimentation rate (ESR), albumin and other myocardial enzyme parameters in the myocardial damage group were higher than those in the group without myocardial damage (P < 0.05), and the median age and platelet/neutrophil ratio (PNR) were lower than those in the group without myocardial damage (P < 0.05); there was no significant difference in general data such as gender, duration of fever, length of hospital stay, the incidence of severe pneumonia between the two groups (P > 0.05); multivariate logistic regression analysis showed that median age, NLR level and extrapulmonary manifestations (except myocardial damage) were the main factors affecting myocardial damage in children with MPP (P < 0.05); considering the interaction between NLR and PNR. We also performed ROC curve analysis for PNR. Among the univariate factors, PNR had the highest predictive value, and the specificity was as high as 86.9%. The combined area under the curve of the four indicators was 0.747, higher than that of the univariate factor (P < 0.001), with a predictive sensitivity of 83.9% and a specificity of 63.9%.

CONCLUSION

Children with MPP younger than 6.79 years have extrapulmonary manifestations (acute sinusitis, acute otitis media, etc.), NLR > 2.41, and PNR < 44.74 in blood routine are more likely to develop myocardial damage.

CLINICAL TRIAL NUMBER

Not applicable.

Predictive value of plasma sB7-H3 and YKL-40 in pediatric refractory Mycoplasma pneumoniae pneumonia

Objective

This study investigated the clinical significance of plasma sB7-H3 and YKL-40 levels in children with refractory Mycoplasma pneumoniae pneumonia (RMPP).

Methods

A total of 182 RMPP patients (103 general Mycoplasma pneumoniae patients and 79 RMPP patients) were included. sB7-H3, YKL-40, and other inflammatory factors were measured. Independent factors associated with the early diagnosis of RMPP were determined. The value of each independent risk factor in predicting RMPP was evaluated.

Results

The RMPP group reported significantly longer hospital stays and total fever durations. Levels of C-reactive protein, D-dimer, IL-13, IL-6/-10, sB7-H3, and YKL-40 were higher in the RMPP group. sB7-H3 was positively correlated with IL-13, IL-6, and IL-4, whereas YKL-40 was positively correlated with all of the above indicators (IL-5 was also included). sB7-H3 and YKL-40 were independent risk factors for RMPP. The critical values for sB7-H3 and YKL-40 were 3.525 and 313.3 ng/mL, respectively. sB7-H3 and YKL-40 had areas under the curve of 0.734 and 0.859, respectively. YKL-40 had high sensitivity and specificity of 88.61 and 87.38%, respectively. Both indicators had predictive value, YKL-40 had the highest predictive ability for RMPP.

Conclusion

Detection of sB7-H3 and YKL-40 levels in the plasma may be useful in diagnosing RMPP early in the disease process.

Correlation of DNA load, genotyping, and clinical phenotype of Mycoplasma pneumoniae infection in children

Introduction

This study aimed to investigate the correlation between Mycoplasma pneumoniae (MP)-DNA load in the bronchoalveolar lavage fluid (BALF) of children with MP pneumonia (MPP) and its subtypes, relevant laboratory data, imaging, extrapulmonary complications in infected children, and its clinical significance in evaluating the disease.

Methods

Children hospitalized with MPP at Tianjin Children's Hospital between December 2017 and December 2020 were selected for the study, excluding those with mixed viral, bacterial, and fungal infections. Children were divided into low- and high-load groups according to the MP DNA load in BALF using real-time quantitative fluorescence polymerase chain reaction (PCR). After a successful MP culture, positive specimens were subjected to PCR-Restriction fragment length polymorphism and Multiple-locus variable number tandem repeat analysis typing. Basic data, clinical information, laboratory data, and radiological results were collected from all children included in the study.

Results

The PI-I type dominated the different load groups. Children in the low-load group had more wheezing and shortness of breath; however, children in the high-load group had a higher length of hospitalization, maximum fever temperature, higher chills/chilliness, incidence of abdominal pain, and higher C-reactive protein (CRP), procalcitonin (PCT) and aspartate aminotransferase (AST) levels. Children in the high-load group were more likely to have imaging changes such as pleural effusion, and the incidence of respiratory infections and extrapulmonary complications was higher than that of those in the low-load group. We applied Spearman's correlation analysis to clarify the relationship between MP DNA load and the clinical severity of MPP. We found that MP DNA load was positively correlated with length of hospitalization, maximum fever temperature, CRP, PCT, Interleukin-6 (IL-6), and AST levels, and negatively correlated with fever and cough durations, white blood cell count (WBC), and proportion of monocytes (MONO). The degree of correlation was as follows: length of hospitalization > IL-6 > cough duration > AST > fever duration > PCT > WBC > proportion of MONO > maximum fever temperature > CRP levels.

Conclusions

MP DNA load was not correlated with MP typing but was significantly correlated with the children's clinical phenotype. Therefore, the MP DNA load helps in the early diagnosis of infection and can better predict disease regression.

Mutations in domain V of Mycoplasma pneumoniae 23S rRNA and clinical characteristics of pediatric M. pneumoniae pneumonia in Nanjing, China

OBJECTIVE

To investigate the prevalence of mutations in domain V of Mycoplasma pneumoniae (MP) 23S ribosomal RNA (rRNA) and the clinical characteristics of pediatric MP pneumonia (MPP) in Nanjing, China.

METHODS

Domain V of 23S rRNA was sequenced in MP strains collected from children diagnosed with MPP in Nanjing. Clinical and laboratory data were obtained.

RESULTS

Among the 276 MP strains, 255 (92.39%) harbored mutations, primarily A2063G in domain V of MP 23S rRNA. When children were stratified according to the presence or absence of mutations, no significant differences were found in sex, age, the MP DNA load at enrollment, lymphocyte counts, pulmonary complications, immunomodulator levels, fever duration, the duration of fever after macrolide therapy, and hospital stay. The prevalence of refractory MPP in the two groups was similar. Children with refractory MPP exhibited higher MP DNA loads than those with non-refractory MPP.

CONCLUSIONS

Despite the high prevalence of the A2063G mutation in domain V of MP 23S rRNA, mutations were not associated with the clinical characteristics of MPP. The MP DNA load significantly differed between refractory and non-refractory MPP.

The combination of initial markers to predict refractory Mycoplasma pneumoniae pneumonia in Chinese children: a case control study

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.

Clinical characteristics of refractory mycoplasma pneumoniae pneumonia in children treated with glucocorticoid pulse therapy

BACKGROUND

To observe the effect of corticosteroids in the treatment of children with refractory Mycoplasma pneumoniae pneumonia (RMPP) under different doses, to summarize the clinical features of children treated with glucocorticoid pulse therapy.

METHODS

The clinical data of 125 children with RMPP hospitalized in Tianjin Children's Hospital from September 2018 to October 2019 were retrospectively analyzed. They were divided into two groups according to the dose of hormone. Compare the clinical features, laboratory findings, and imaging between the two groups, and use meaningful related indicators as ROC curves to find reference indicators for pulse therapy.

RESULTS

(1) The median age of the group II was older than that of the group I(P < 0.05). (2) We found more severe presentations, higher incidence of extra-pulmonary complications and more serious radiological findings in group II, which needed oxygen more often, higher the hormone, higher usage rate of gamma globulin, higher usage rate of bronchoscopy, and higher incidence of plastic bronchitis(P < 0.05). (3) WBC, CRP, LDH, FER, D-D dimer, APTT, TT, PCT, IL-6 and the percentage of neutrophils in peripheral blood in Group II were higher than those in Group I(P < 0.05). (4) In ROC curve analysis, CRP, LDH, FER, and neutrophils of leukocyte classification were independent related factors that could be used as valuable predictors of methylprednisolone pulse therapy for RMPP in children. The cut-off values were CRP44.45 mg/L, LDH590IU/L, FER411ng/L, and neutrophils in leukocyte classification were 73.75%, respectively.

CONCLUSION

CRP ≥ 44.45 mg/L, LDH ≥ 590 IU/L, FER ≥ 411 ng/L, neutrophil≥73.75%, lung consolidation, and pleural effusion may be predictors that guide the treatment of RMPP with pulse dose of GC.

Correlation Between the Clinical Severity, Bacterial Load, and Inflammatory Reaction in Children with Mycoplasma Pneumoniae Pneumonia

Given the lack of defining features in the clinical manifestations and radiographic findings for children with mycoplasma pneumoniae pneumonia (MPP), quantitative polymerase chain reaction (qPCR) has become a useful diagnostic method. This study was performed to explore the relationship between the qPCR findings, clinical symptoms, and inflammatory markers in children with MPP. Four hundred children with MPP have been enrolled in this retrospective analysis. All clinical and analytical information, including mycoplasma pneumoniae (MP) PCR results, has been collected. Based on the PCR results, the patients were divided into groups with load values (copy number) < 10⁵ (54 cases), ≥10⁵ and <10⁶ (71 cases), ≥10⁶ and <10⁷ (112 cases), ≥10⁷ and ≤10⁸ (114 cases), and >10⁸ (49 cases). The clinical features (including symptoms and signs) and inflammatory indicators were compared among the groups. The incidence of high fever (above 39°C), thermal peak during the entire hospitalization period, fever duration, days of hospitalization, and plasma lactate dehydrogenase (LDH) levels were statistically correlated with the MP PCR load value in children with MPP. The analysis of relevance degree showed the correlative order as a thermal peak of hospitalization > duration of fever > period of hospitalization > LDH value > C-reactive protein value. The host immune response was significantly greater in the complication group than in the non-complication group.

Identify clinical factors related to Mycoplasma pneumoniae pneumonia with hypoxia in children

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.

Development and validation of a simple-to-use nomogram for predicting refractory Mycoplasma pneumoniae pneumonia in children

OBJECTIVE

This study aimed to develop and validate a simple-to-use nomogram for predicting refractory Mycoplasma pneumoniae pneumonia (RMPP) in children.

METHODS

A total of 73 children with RMPP and 146 children with general Mycoplasma pneumoniae pneumonia were included. Clinical, laboratory, and radiological data were obtained. A least absolute shrinkage and selection operator (LASSO) regression model was used to determine optimal predictors. The nomogram was plotted by multivariable logistic regression. The performance of the nomogram was assessed by calibration, discrimination, and clinical utility.

RESULTS

The LASSO regression analysis identified lactate dehydrogenase, albumin, neutrophil ratio, and high fever as significant predictors of RMPP. This nomogram-illustrated model showed good discrimination, calibration, and clinical value. The area under the receiver operating characteristic curve of the nomogram was 0.884 (95% CI, 0.823-0.945) in the training set and 0.881 (95% CI, 0.807-0.955) in the validating set. Calibration curve and Hosmer-Lemeshow test showed good consistency between the predictions of the nomogram and the actual observations, and decision curve analysis showed that the nomogram was clinically useful.

CONCLUSION

A simple-to-use nomogram for predicting RMPP in early stage was developed and validated. This may help physicians recognize RMPP earlier.

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

Objective Acute organ embolism in children with Mycoplasma pneumoniae pneumonia (MPP) has been reported, but changes in coagulation are unclear. This study aimed to investigate changes in coagulation in children with MPP. Methods A total of 185 children with MMP (cases) and 117 healthy children (controls) were recruited. We measured prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), and plasma fibrinogen (FIB) and D-dimer levels. Results Plasma FIB (3.39 ± 0.96 g/L vs 2.93 ± 0.6 6g/L, t = 4.50) and D-dimer (326.45 ± 95.62mg/L vs 263.93 ± 103.32mg/L, t=5.36) in MPP children were higher than controls and PT (9.54 ± 4.97S vs 11.48 ± 5.96S, t=3.05) and APTT (31.41 ± 12.01S vs 38.38 ± 11.72S, t=4.95) were shorter than controls. FIB, D-dimer, PT, and APTT were not different between the high IgM-titre and low-titre groups. The areas under the receiver operating characteristic curves in cases and controls for plasma FIB and D-dimer levels were 0.654 (95% confidence interval [CI], 0.593-0.716, P = 0.031) and 0.682 (95% CI, 0.619-0.744, P = 0.032), respectively. Conclusions Children with MPP have a higher risk of blood coagulation and thrombosis. Controlling these problems should be considered as soon as possible.

Mycoplasma pneumoniae 23S rRNA A2063G mutation does not influence chest radiography features in children with pneumonia

Objective

To measure the rate of the A2063G mutation in the Mycoplasma pneumoniae (M. pneumoniae) 23S rRNA domain V in children with pneumonia and to determine the correlation between radiographic findings and the presence of the A2063G mutation.

Methods

Patients who were hospitalized with a confirmed diagnosis of M. pneumoniae pneumonia were enrolled in this study. M. pneumoniae strains were collected for genotype analysis. Chest radiography was performed on all children prior to and following macrolide treatment. Clinical and imaging data were obtained.

Results

Of 211 patients, 195 (92.42%) harboured M. pneumoniae with the A2063G mutation. No significant differences were identified in inflammation score, chest radiography inflammation absorption grade before and after macrolide treatment, or pulmonary complications (atelectasis, hydrothorax, or pleuritis) prior to macrolide treatment when children were stratified based on the presence or absence of the A2063G mutation.

Conclusions

A high proportion of children with pneumonia harboured strains of M. pneumoniae with the A2063G mutation in the 23S rRNA domain V. However, no obvious chest radiographic features of M. pneumoniae pneumonia were associated with the A2063G variant.

Transcriptome analysis of bronchoalveolar lavage fluid from children with severe Mycoplasma pneumoniae pneumonia reveals novel gene expression and immunodeficiency

BACKGROUND

A growing number of severe Mycoplasma pneumoniae pneumonia (MPP) cases have been reported recently. However, the pathogenesis of severe MPP is not clear. In the current study, transcriptome sequencing was used to identify gene expression and alternative splicing profiles to provide insights into the pathogenesis of severe MPP.

METHODS

RNAs of bronchoalveolar lavage fluid (BALF) samples from three severe MPP children and three mild MPP children were analyzed respectively by deep sequencing followed by computational annotation and quantification.

RESULTS

The gene expression analysis revealed 14 up-regulated and 34 down-regulated genes in severe MPP children comparing to mild MPP children. The top 10 most up-regulated genes were IGHV1-69, CH17-472G23.1, ATP1B2, FCER2, MUC21, IL13, FCRLB, CLEC5A, FAM124A, and INHBA. The top 10 most down-regulated genes were OSTN-AS1, IL22RA2, COL3A1, C1orf141, IGKV2-29, RP11-731F5.2, IGHV4-4, KIRREL, DNASE1L3, and COL6A2. Clustering analysis revealed similar expression pattern of CLEC5A, IL13, FCER2, and FLT1. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses revealed changes related to primary immunodeficiency in severe MPP children comparing to mild MPP children; the pathway involves CD19, TNFRSF13C, CD79A, and AICDA genes. Among the differentially expressed genes, significant alternative splicing events were found in FCER2 and FCRLA.

CONCLUSIONS

The current study on RNA sequencing provides novel insights into the pathogenesis of severe MPP in terms of gene expression and alternative splicing. The up-regulation of IL13, FCER2, FLT1, and CLEC5A and the down-regulation of CD79A, AICDA, CD19, and TNFRSF13C may contribute to the pathogenesis of severe MPP. The differential expressions of FCER2 and FCRLA could be due to their alternative splicing.

The Clinical Characteristics and Predictors of Refractory Mycoplasma pneumoniae Pneumonia in Children

Objective

To analyze the clinical characteristics of refracory Mycoplasma pneumoniae pneumonia (RMPP), and explore the related factors predicting RMPP.

Methods

Retrospective analysis was performed on 634 children with Mycoplasma pneumoniae pneumonia (MPP) hospitalized in our hospital between January 1, 2011 and December 31, 2014. The clinical features, laboratory data, radiological findings between the RMPP group and the general Mycoplasma pneumoniae pneumonia (GMPP) group were compared and the predictive values of related factors were analyzed.

Results

The median age of the RMPP patients (n = 145) was much older than that of the GMPP patients (n = 489) (P<0.01). We also found more severe presentations, higher incidence of extra-pulmonary complications and more serious radiological findings in RMPP group, which needed oxygen more often, longer antibiotics administration and intensive care (P<0.05). Meanwhile, the levels of C-reactive protein (CRP), lactic dehydrogenase (LDH), immunoglobulin A (IgM), interleukin (IL)-6, IL-10, interferon gamma (IFN-γ) and the percentage of neutrophils, CD8+ in RMPP group were significantly higher than those in GMPP group (P<0.05); while the levels of prealbumin (PAB) were lower than that in GMPP group (P<0.01). In ROC curve analysis, the percentage of neutrophil, CRP, LDH, PAB, IL-6, IL-10 and IFN-γ were useful for differentiating patients with RMPP from those with GMPP. Multiple logistic regression analysis showed that the CRP≥16.5mg/L, LDH ≥417IU/L and IL-6 ≥14.75pg/ml were significant predictors regarding to RMPP.

Conclusions

CRP≥16.5mg/L, LDH ≥417IU/L and IL-6 ≥14.75pg/ml might be the significant predictors of RMPP in children, which can aid in early recognition of RMPP.

Lesson of the month 1: Pericardial mass and cardiac tamponade associated with Mycoplasma pneumoniae

Mycoplasma pneumoniae primarily causes respiratory tract infections. Extrapulmonary manifestations are seen in 20-25% of cases. Cardiac involvement is rarely reported. We present a unique case of a pericardial mass and cardiac tamponade associated with a Mycoplasma pneumoniae pneumonia. This required emergency pericardial fenestration. The patient improved dramatically postoperatively on antibiotics and there was no recurrence of the pericardial effusion on follow up. This case highlights the often forgotten invasive properties of a common respiratory tract pathogen and emphasises the need to consider this easily treatable entity in the differential diagnosis of idiopathic pericardial effusions.

More complications occur in macrolide-resistant than in macrolide-sensitive Mycoplasma pneumoniae pneumonia

We sought to understand the situation of macrolide-resistant genotypes of Mycoplasma pneumoniae, and analyze the relationship between macrolide-resistant genotypes and clinical manifestations of Mycoplasma pneumoniae pneumonia (MPP). Full-length sequencing of the 23S rRNA gene of M. pneumoniae was performed in 235 nasopharyngeal aspirates (NPAs) from children with MPP. We also retrospectively compared the clinical characteristics of macrolide-resistant (MR) M. pneumoniae infections and macrolide-sensitive (MS) M. pneumoniae infections. A total of 206 patients had point mutations in the M. pneumoniae 23S rRNA gene, and these patients are referred to as MR patients. The remaining 29 patients without point mutations are referred to as MS patients. Among 206 MR patients, 199 (96.6%) had A2063G mutations, 6 had A2063T mutations, and the remaining patients had an A2064G mutation. Among the clinical manifestations, we found that the median fever durations were 8 days (range, 0 to 42 days) and 6 days (0 to 14 days) (P < 0.01), the median hospitalization durations were 8 days (2 to 45 days) and 6 days (3 to 16 days) (P < 0.01), and the median fever durations after macrolide therapy were 5 days (0 to 42 days) and 3 days (0 to 10 days) (P < 0.01), respectively, in the MR and MS groups. We also found that the incidence of extrapulmonary complications in the MR group was significantly higher than that in the MS group (P < 0.05). Moreover, the radiological findings were more serious in the MR group than in the MS group (P < 0.05). The increasing prevalence of MR M. pneumoniae has become a significant clinical issue in the pediatric patients, which may lead to more extrapulmonary complications and severe clinical features and radiological manifestations.

Age-specific Mycoplasma pneumoniae pneumonia-associated myocardial damage in children

OBJECTIVE

To measure Mycoplasma pneumoniae pneumonia (MPP)-associated myocardial damage in different age groups of children with pneumonia.

METHODS

Children aged 0-14 years with pneumonia and myocardial damage (serum creatine kinase isoenzyme-MB [CK-MB] concentration >25 U/l) were enrolled in the study. The children were classified as Mycoplasma pneumoniae immunoglobulin M positive (M. pneumoniae IgM+) or negative (M. pneumoniae IgM-) based on a serological test. Children were stratified into four age groups in order to analyse age-specific MPP-associated myocardial damage.

RESULTS

The incidence of fever was significantly higher in children who were M. pneumoniae IgM+ compared with M. pneumoniae IgM- children. The median serum CK-MB concentration was significantly higher in children who were M. pneumoniae IgM+ compared with those who were M. pneumoniae IgM-. Children who were M. pneumoniae IgM+ in the 13-36 months and 72 months-14 years age groups had significantly higher median serum CK-MB concentrations than those who were M. pneumoniae IgM- in the same age group.

CONCLUSIONS

M. pneumoniae infection was associated with greater myocardial damage in children aged 13-36 months and 72 months-14 years. This suggests age-specific immune responses to M. pneumoniae.

A case of acute myopericarditis associated with Mycoplasma pneumoniae infection in a child

Mycoplasma pneumoniae (M. pneumoniae) primarily causes respiratory tract infections in persons aged 5-20 years. Tracheobronchitis and bronchopneumonia are the most commonly recognized clinical symptoms associated with M. pneumoniae infection. Complications of this infection are unusual; in particular, cardiac involvement is very rare and is generally accompanied by pneumonia. Nonrespiratory illness can therefore involve direct invasion by M. pneumoniae or autoimmune mechanisms, as suggested by the frequency of cross reaction between human antigens and M. pneumoniae. Herein, we report a case of severe acute myopericarditis with pneumonia caused by M. pneumoniae in a healthy young child who presented with fever, lethargy, oliguria and dyspnea. She survived with aggressive therapy including clarithromycin, intravenous immunoglobulin, inotropics, and diuretics. The patient was discharged on the 19th day after admission and followed up 1 month thereafter at the outpatient clinic without sequelae.