OBJECTIVEMycoplasma pneumoniae (Mp) infection is one of major causes of community-acquired pneumonia. Isolation and culture of Mp are very difficult, fluorescent quantitative PCR is a new technique to detect Mp. The aim of this study was to explore the diagnostic value of fluorescent quantitation PCR for Mp infection.

METHODMp-DNA from the deep respiratory tract secretion of children suffering from pneumonia was tested by a fluorescent quantitative PCR. Totally 256 cases who were positive for Mp DNA were enrolled into this study, 164 (64.1%) were male, 92 (35.9%) were female; the age ranged from 9 days to 16 years. All the patients also had results of Mp-IgM test. These patients were divided into 2 groups according to the result of Mp-IgM detection, namely, Mp-IgM positive and negative groups. Area under the roc curve (Az) was used as the index to evaluate the diagnostic value of fluorescent quantitation PCR for Mp detection. The number of Mp-DNA copies, age and course of disease of the 2 groups were also compared.

RESULTS(1) Diagnostic accuracy of fluorescent quantitative PCR for detecting Mp infection was that Az = 0.641. (2) The number of copies of the cases in Mp-IgM positive group was 5.42 +/- 1.26 [log(Mp-DNA copy/ml)], while that of Mp-IgM-negative group was 4.87 +/- 1.29 [log(Mp-DNA copy/ml), t = 3.43, P < 0.05]. (3) The age of Mp-IgM positive group was dramatically younger than Mp-IgM negative group (P < 0.001).

CONCLUSIONThe diagnostic accuracy of fluorescent quantitative PCR for mycoplasma pneumoniae (Mp) infection is low; however for children whose immunologic systems are not fully developed, this technique has some diagnostic value, and higher number of Mp-DNA copies may support diagnosis of Mp infection.

Adolescent ; Child ; Child, Preschool ; Female ; Humans ; Immunoglobulin M ; blood ; Infant ; Infant, Newborn ; Male ; Mycoplasma pneumoniae ; genetics ; immunology ; isolation & purification ; Pneumonia, Mycoplasma ; diagnosis ; Polymerase Chain Reaction ; methods

BACKGROUNDMycoplasma pneumoniae (M. pneumoniae) is a frequent cause of respiratory tract infections. However, there is deficient knowledge about the clinical manifestations of M. pneumoniae infection. We described the clinical and laboratory findings of M. pneumoniae pneumonia in hospitalized children who were all diagnosed by a ≥ fourfold increase in antibody titer.

METHODSM. pneumoniae antibodies were routinely detected in children admitted with acute respiratory infection during a one-year period. The medical history was re-collected from children whose M. pneumoniae antibody titer increased ≥ fourfold at the bedside by a single person, and their frozen paired serum samples were measured again for the M. pneumoniae antibody titer.

RESULTSOf the 635 children whose sera were detected for the M. pneumoniae antibody, paired sera were obtained from 82 and 29.3% (24/82) showed a ≥ fourfold increase in antibody titer. There were 24 cases, nine boys and 15 girls, aged from two to 14 years, whose second serum samples were taken on day 9 at the earliest after symptom onset; the shortest interval was three days. All children presented with a high fever (≥ 38.5°C) and coughing. Twenty-one had no nasal obstruction or a runny nose, and five had mild headaches which all were associated with the high fever. The disease was comparatively severe if the peak temperature was > 39.5°C. All were diagnosed as having pneumonia through chest X-rays. Four had bilateral or multilobar involvement and their peak temperatures were all ≤ 39.5°C. None of the children had difficulty in breathing and all showed no signs of wheezing.

CONCLUSIONSThe second serum sample could be taken on day 9 at the earliest after symptom onset meant that paired sera could be used for the clinical diagnosis of M. pneumoniae pneumonia in children at the acute stage. M. pneumoniae is a lower respiratory tract pathogen. Extrapulmonary complications were rare and minor in our study. High peak temperature (> 39.5°C) is correlated with the severity of M. pneumoniae pneumonia in children.

Acute Disease ; Adolescent ; Antibodies, Bacterial ; blood ; Child ; Child, Hospitalized ; Child, Preschool ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; immunology ; Pneumonia, Mycoplasma ; complications ; diagnosis ; drug therapy ; Radiography, Thoracic

Diagnosis of Mycoplasma pneumoniae infection is important due to its variable clinical manifestations and absence of response to beta-lactams. Introduction of enzyme immunoassays (EIAs) for serologic diagnosis of M. pneumoniae has made it possible to separate the analyses of specific IgG and IgM antibodies. We compared four different commercial EIAs, ImmunoWELL IgG, IgM (GenBio), Medac IgG, IgA, IgM (Medac), Platelia IgG, IgM (Sanofi Pasteur), and Ridascreen IgG, IgA, IgM (r-Biopharm) with indirect particle agglutination assay (PA), Serodia-MycoII (Fujirebio). We tested 91 specimens from 73 pediatric patients (2-17 yr) hospitalized at a tertiary-care hospital between December 2005 and January 2006. The measurements of IgM EIAs were correlated with PA titers (Spearman's correlation coefficient, from 0.89 to 0.92) with high concordance rates, ranging from 82.4% to 92.3%. However, some negative IgM-EIA results in PA-positive specimens indicated that serial samplings with convalescent sera would be necessary to confirm M. pneumoniae infection.
Adolescent ; Antibodies, Bacterial/chemistry ; Child ; Child, Preschool ; Female ; Humans ; Immunoenzyme Techniques/*methods ; Immunoglobulin G/*chemistry ; Immunoglobulin M/*chemistry ; Infant ; Male ; Microbiology ; Mycoplasma pneumoniae/chemistry/*immunology/metabolism ; Pneumonia, Mycoplasma/*diagnosis/*immunology ; Polymerase Chain Reaction ; Serologic Tests

The aim of study was to describe Mycoplasma pneumoniae epidemics in a hospital-based population. Special attention was paid to the relationship between antibody titer to M. pneumoniae and sex, age, and atopy. During the eight 6-month periods between January 2000 and December 2003, serum samples were obtained from 1,319 Korean children who presented with respiratory symptoms, and were examined for antibodies to M. pneumoniae using the indirect particle agglutination test. Geometric mean antibody titers peaked in the second half of 2000 and then decreased gradually, a second peak occurred in the second half of 2003. Likewise, the frequency of high antibody titers (>or=1:640) also peaked during these two periods. Antibody titers in children aged 0-3 yr were lower than in older children during both peak periods and for 2 yr after the first peak. Sex and atopy had no effect on antibody titers. During the years 2000-2003, geometric mean antibody titers and the frequencies of high antibody titers varied with time. These changes suggest a cyclic pattern of M. pneumoniae infection, with two epidemic peaks separated by 3 yr.
Adolescent ; Age Distribution ; Antibodies, Bacterial/*blood ; Child ; Child, Preschool ; Disease Outbreaks/statistics & numerical data ; Female ; Humans ; Infant ; Infant, Newborn ; Korea/epidemiology ; Male ; Mycoplasma pneumoniae/*immunology ; Pneumonia, Mycoplasma/*blood/epidemiology/immunology ; Research Support, Non-U.S. Gov't ; Sex Distribution ; Time Factors

Mycoplasma pneumoniae and Chlamydia pneumoniae have been suggested to take part in the acute exacerbation of bronchial asthma and chronic obstructive pulmonary disease (COPD). Several studies have questioned whether they may play pathogenic roles in connection with bronchial asthma and COPD. This study was designed to evaluate the seroprevalences of M. pneumoniae and C. pneumoniae in stable asthma and COPD patients, and to compare with control patients. The medical records of one hundred forty patients who underwent M. pneumoniae and C. pneumoniae serology were retrospectively reviewed. Seroprevalences of M. pneumoniae and C. pneumoniae in the asthma group (11.1% and 8.3%, respectively) were higher than in the control group (4.4% and 2.2%, respectively) without statistical significance. The seroprevalence of M. pneumoniae in the COPD group (16.9%) was significantly higher than in the control group, and the seroprevalence of C. pneumoniae in the COPD group (3.4%) was higher than in the control group without statistical significance. This study raises important questions about the relation of M. pneumoniae and C. pneumoniae infection with stable asthma or COPD.
Adult ; Aged ; Asthma/*microbiology ; Chlamydophila Infections/*epidemiology ; Chlamydophila pneumoniae/immunology ; Female ; Humans ; Male ; Middle Aged ; Pneumonia, Mycoplasma/*epidemiology ; Pulmonary Disease, Chronic Obstructive/*microbiology ; Seroepidemiologic Studies

A case of inflammatory pseudotumor of the lung occurring in a six-year-old boy is reported with clinicopathologic findings, including its ultrastructure. The patient had had frequent upper respiratory tract infections, and one and half year before the discovery of the lung mass, he suffered from pneumonia of the right lung, which was serologically proven to be a mycoplasma pneumoniae infection. Exploratory thoracotomy revealed a large mediastinal mass that was removed together with the right middle and lower lobes of the lung. The mass arose from the lung with an endobronchial element. Microscopically, the mass was composed of a variety of inflammatory and mesenchymal cells, including plasma cells, histiocytes, lymphocytes, and fibroblast-like spindle cells. Ultrastructurally, the spindle-shaped mesenchymal cells were either fibroblasts or myofibroblasts. At the time of diagnosis of the inflammatory pseudotumor of the lung, the serum titer of antimycoplasma antibody rose again, and the lung parenchyma adjacent to the mass showed interstitial pneumonia with features of bronchiolitis obliterans. The present case suggests that the inflammatory pseudotumor of the lung could be a postinflammatory lesion associated with mycoplasma pneumoniae infection.
Antibodies, Bacterial/blood ; Bronchiolitis Obliterans/complications ; Child ; Diagnosis, Differential ; Fibroma/etiology/*pathology/surgery ; Humans ; Lung Neoplasms/etiology/*pathology/surgery ; Male ; Mycoplasma pneumoniae/immunology/*pathogenicity ; Pneumonia, Mycoplasma/complications/microbiology/*pathology ; Tomography, X-Ray Computed

This study investigated the serum vascular endothelial growth factor (VEGF) levels in children with community-acquired pneumonia. Serum VEGF levels were measured in patients with pneumonia (n=29) and in control subjects (n=27) by a sandwich enzyme-linked immunosorbent assay. The pneumonia group was classified into bronchopneumonia with pleural effusion (n=1), bronchopneumonia without pleural effusion (n=15), lobar pneumonia with pleural effusion (n=4), and lobar pneumonia without pleural effusion (n=9) groups based on the findings of chest radiographs. We also measured serum IL-6 levels and the other acute inflammatory parameters. Serum levels of VEGF in children with pneumonia were significantly higher than those in control subjects (p<0.01). Children with lobar pneumonia with or without effusion showed significantly higher levels of serum VEGF than children with bronchopneumonia. For lobar pneumonia, children with pleural effusion showed higher levels of VEGF than those without pleural effusion. Children with a positive urinary S. pneumonia antigen test also showed higher levels of VEGF than those with a negative result. Serum IL-6 levels did not show significant differences between children with pneumonia and control subjects. Serum levels of VEGF showed a positive correlation with the erythrocyte sedimentation rate in the children with pneumonia. In conclusion, VEGF may be one of the key mediators that lead to lobar pneumonia and parapneumonic effusion.
Vascular Endothelial Growth Factor A/*blood ; Streptococcus pneumoniae/growth & development/immunology ; Pneumonia, Bacterial/*blood/complications/microbiology ; Pleural Effusion/*blood/complications/microbiology ; Mycoplasma pneumoniae/growth & development/immunology ; Male ; Interleukin-6/blood ; Infant ; Humans ; Female ; Enzyme-Linked Immunosorbent Assay ; Community-Acquired Infections/blood/microbiology ; Child, Preschool ; Child ; Antigens, Bacterial/immunology ; Antibodies, Bacterial/immunology ; Adolescent

Local epidemiologic data on the etiologies of patients hospitalized with community-acquired pneumonia (CAP) is needed to develop guidelines for clinical practice. This study was conducted prospectively to determine the proportion of atypical bacterial pathogens in adults patients hospitalized with CAP in Korea between October 2001 and December 2002. Microbiological diagnosis was determined by serology for antibodies to Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella pneu-mophila. Nucleic acid of M. pneumoniae and C. pneumoniae in respiratory samples and Legionella antigen in urine samples were detected. The study population consisted of 126 patients (71 males, 55 females), averaging 54.6 yr (SD+/-17.8), whose paired sera were available. An etiologic diagnosis for atypical pathogens was made in 18 patients (14.3%): C. pneumoniae 9 (7.1%), M. pneumoniae 8 (6.3%), and L. pneumophila 3 patients (2.4%). Streptococcus preumoniae and other typical pathogens were isolated from 36 patients (28.6%). Of 126 patients, 16 (12.7%) were admitted to intensive care unit and atypical pathogens were identified in 5 patients (31.3%). Initial clinical features of patients with pneumonia due to atypical, typical or undetermined pathogens were indistinguishable. We conclude that atypical pathogens should be seriously considered in hospitalized patients with CAP, when initiating empiric treatment in Korea.
RNA, Ribosomal, 16S/genetics ; Prospective Studies ; Polymerase Chain Reaction ; Pneumonia, Bacterial/blood/*microbiology/urine ; Mycoplasma pneumoniae/genetics/immunology/*isolation & purification ; Middle Aged ; Male ; Legionella pneumophila/genetics/immunology/*isolation & purification ; Korea ; Humans ; Hospitalization/statistics & numerical data ; Female ; Community-Acquired Infections/microbiology ; Chlamydophila pneumoniae/genetics/immunology/*isolation & purification ; Antigens, Bacterial/urine ; Antibodies, Bacterial/blood ; Aged ; Adult