Diagnosis Of Mycoplasma Pneumoniae Infection Research Articles

Clinical significance of Mycoplasma pneumoniae specific IgM titer in children hospitalized with Mycoplasma pneumoniae pneumonia

BackgroundThe present study aimed to identify the clinical significance of Mycoplasma pneumoniae (MP)-specific immunoglobulin M (IgM) titer, in addition to a diagnosis of MP infection, in children with MP pneumonia.MethodsThis study was performed in 155 children hospitalized with MP pneumonia. The clinical features and laboratory and radiographic findings on admission in children with positive or negative MP-specific IgM titers were retrospectively reviewed from the electronic medical records.ResultsThe mean age of the included children was 6.0 years, and 118 (76.1%) of the children were positive for MP-specific IgM. A longer duration between symptom onset and admission (adjusted odds ratio [aOR] 1.47, 95% confidence interval [CI] 1.24–1.75), longer duration of symptoms during the illness (aOR 1.15, 95% CI 1.02–1.30), and development of extra-pulmonary manifestations (aOR 9.16, 95% CI 1.96–42.81) were significantly associated with a positive MP-specific IgM titer. Serum lactate dehydrogenase levels (aOR 1.00, 95% CI 1.00–1.01) and pneumonic infiltration involving > 50% of the total lung volume on chest radiography (aOR 4.68, 95% CI 1.12–19.55) were associated with positive MP-specific IgM in children with MP pneumonia. A poor response to stepwise treatment for MP pneumonia was more common in children with a positive MP-specific IgM titer than those with a negative MP-specific IgM titer on admission.ConclusionsA positive MP-specific IgM titer at diagnosis of MP pneumonia may partially suggest an exaggerated immune response with a higher disease burden compared to children with MP pneumonia with a negative MP-specific IgM titer.

Consideration in treatment decisions for refractory Mycoplasma pneumoniae pneumonia.

Mycoplasma pneumoniae (MP) is the most common cause of childhood bacterial pneumonia. Although macrolide is known to be effective as a first-line therapy, the proportion of macrolide resistance in MP pneumonia has strikingly increased during recent 2 decades in East Asia. This is challenging to physicians since they have to decide more often whether to use secondary treatment. Diagnostic methods to detect macrolide-resistance of MP are currently not available in Korean hospitals. Even in the diagnosis of MP infection, both serologic and molecular test have limitation: inability to differentiate current illness from carriage or asymptomatic infection. Combining these 2 diagnostic methods and excluding infection caused by other respiratory pathogens allow a more reliable diagnosis. This effort is even more demanding in recent years to keep children from unnecessary exposure to secondary antibiotics. Although several observational studies have reported that tetracycline and fluoroquinolone, which are considered in the treatment of refractory MP pneumonia, have efficacy of shortening the duration of fever and respiratory symptoms, those findings need to be proven by well-designed prospective studies. The use of tetracycline and fluoroquinolone in children is generally tolerable, as supported by many observational data. However, since concerns about side effects still remain, careful consideration about benefits and risks is needed to decide their use.

Mycoplasma pneumoniae-induced cerebral venous sinus thrombosis with autoimmune hemolytic anemia

Mycoplasma pneumoniae (MP) is a common organism causing pneumonia in school-going children. Although the disease is usually mild, it can rarely lead to severe extrapulmonary complications which may be life-threatening. We hereby report a case of an 8-year-old male child who presented with fever, cough, a maculopapular rash, and difficulty in breathing for 8 days who, after initially receiving treatment as community-acquired pneumonia with synpneumonic effusion, went on to develop severe autoimmune hemolytic anemia and cerebral venous thrombosis with features of vasculitis. With utilization of DNA polymerase chain reaction along with other laboratory parameters, the diagnosis of MP infection was made. The child was treated with oral clarithromycin, pulse dose methylprednisolone, low-molecular-weight heparin, and intravenous immunoglobulin while he also required mechanical ventilation, transfusions, and vasopressor support. He responded to these measures and survived with no neurological sequelae.

Frequency and Clinical Presentation of Mucocutaneous Disease Due to Mycoplasma pneumoniae Infection in Children With Community-Acquired Pneumonia

The diagnosis of Mycoplasma pneumoniae infection as the cause of mucocutaneous disease is challenging because current diagnostic tests are not able to differentiate M pneumoniae infection from carriage. To examine the frequency and clinical presentation of M pneumoniae-induced mucocutaneous disease in children with community-acquired pneumonia (CAP) using improved diagnostics. This prospective, longitudinal cohort study included 152 children aged 3 to 18 years with CAP enrolled in a CAP study from May 1, 2016, to April 30, 2017, at the University Children's Hospital Zurich. Children were inpatients or outpatients with clinically defined CAP according to the British Thoracic Society guidelines. Data analysis was performed from July 10, 2017, to June 29, 2018. Frequency and clinical presentation of M pneumoniae-induced mucocutaneous disease in childhood CAP. Mycoplasma pneumoniae infection was diagnosed by polymerase chain reaction (PCR) of oropharyngeal samples and confirmed with the measurement of specific peripheral blood IgM antibody-secreting cells by enzyme-linked immunospot assay to differentiate M pneumoniae-infected patients from carriers with CAP caused by other pathogens. Mucocutaneous disease was defined as any eruptive lesion that involved skin and/or mucous membranes occurring during the CAP episode. Among 152 enrolled children with CAP (median [interquartile range] age, 5.7 [4.3-8.9] years; 84 [55.3%] male), 44 (28.9%) tested positive for M pneumoniae by PCR; of these, 10 children (22.7%) developed mucocutaneous lesions. All 10 patients with mucocutaneous eruptions tested positive for specific IgM antibody-secreting cells. Skin manifestations were found in 3 cases (2.8%) of M pneumoniae PCR-negative CAP (P < .001). The spectrum of M pneumoniae-induced mucocutaneous disease included M pneumoniae-induced rash and mucositis (3 cases [6.8%]), urticaria (2 cases [4.5%]), and maculopapular skin eruptions (5 cases [11.4%]). Two patients had ocular involvement as the sole mucosal manifestation (bilateral anterior uveitis and nonpurulent conjunctivitis). Patients with M pneumoniae-induced mucocutaneous disease had longer duration of prodromal fever (median [interquartile range], 10.5 [8.3-11.8] vs 7.0 [5.5-9.5] days; P = .02) and higher C-reactive protein levels (median [interquartile range], 31 [22-59] vs 16 [7-23] mg/L; P = .04) than patients with CAP due to M pneumoniae without mucocutaneous manifestations. They were also more likely to require oxygen (5 [50%] vs 1 [5%]; P = .007), to require hospitalization (7 [70%] vs 4 [19%]; P = .01), and to develop long-term sequelae (3 [30%] vs 0; P = .03). Mucocutaneous disease occurred significantly more frequently in children with CAP due to M pneumoniae than in children with CAP of other origins. Mycoplasma pneumoniae-induced mucocutaneous disease was associated with increased systemic inflammation, morbidity, and a higher risk of long-term sequelae.

Diagnosis of Mycoplasma Pneumoniae Infection With Detection of Specific Antibody-secreting Cells in Community-acquired Pneumonia (CAP) Patients of the Randomised Placebo-controlled Multi-centre Effectiveness Trial of Adjunct Betamethasone Therapy

Diagnosis of Mycoplasma Pneumoniae Infection With Detection of Specific Antibody-secreting Cells in Community-acquired Pneumonia (CAP) Patients of the Randomised Placebo-controlled Multi-centre Effectiveness Trial of Adjunct Betamethasone Therapy

Genetic point‐of‐care diagnosis of Mycoplasma pneumoniae infection using LAMP assay

Mycoplasma pneumoniae (MP) is a major pathogen of lower respiratory tract infection (LRTI) in children. A rapid diagnostic method during the acute phase is required for the prescription of effective antibiotics. A prospective, single-centered study was conducted on community-acquired LRTI in children. We regarded the day of fever onset as the first day of illness. In part 1, we studied 191 patients with signs of LRTI. We compared diagnostic reliability using loop-mediated isothermal amplification (LAMP) assay and serological testing at the first visit. In part 2, we evaluated the clinical characteristics of 117 patients with positive LAMP assay. In part 1, 31 patients met the definite MP infection criteria. LAMP assay had a sensitivity of 96.8% and specificity of 100%, whereas enzyme immunoassay had a sensitivity of 38.7% and specificity of 76.9%, and particle agglutination test had a sensitivity of 19.4% and specificity of 93.1%. In part 2, of 106 patients with fever, 100 patients were diagnosed by the day 7 of illness. The diagnosis was made a mean of 3.5 ± 2.1 days after the onset of fever. LAMP assay had excellent sensitivity and specificity for the detection of acute MP infection at the first visit. This assay can diagnose MP infection during the very acute phase. LAMP assay is appropriate for genetic point-of-care diagnosis of MP infection in hospital laboratories.

Significance of dynamic detection of MP-DNA and IgM in the course of mycoplasma pneumoniae infection in children

Objective To explore the values of FQ-PCR for detecting MP-DNA and DIGFA for MP-IgM in the diagnosis of mycoplasma pneumoniae( MP ) infection in children.Methods Respiratory secretions and serum samples were collected.MP-DNA in respiratory secretions was detected by FQ-PCR and serum MP-IgM by DIGFA.Children with positive MP-DNA or MP-IgM alone or both MP-DNA and MP-IgM were diagnosed as MP infection.The changes in the positive rates of MP-DNA and MP-IgM during different courses were observed and analyzed.Results 56 children were diagnosed as MP infection.In the early disease course,the positive rate of MP-DNA was 82.14％ ( 46/56 ),and that of MP-IgM was 35.71％ ( 20/56 ); the former was significantly higher than the latter,with a significant difference ( P＜ 0.05 ).In the middle disease course,the positive rate of MP-DNA dropped to 64.29％ ( 36/56 ),while that of MP-IgM increased to 80.36％ ( 45/56 ); In the recovery course,the positive rate of MP-DNA continued to decline to 1.79％ ( 1/56 ),while that of MP-IgM decreased to 23.21％ ( 13/56 ).Conclusions In children with MP infection, MP-DNA is gradually decreased with the prolongation of the disease course,while MP-IgM is increased until to the middle course and then is declined.FQ-PCR for MP-DNA has a greater value in the diagnosis of MP infection at the early stage,while DIGFA for MP-IgM has a diagnostic significance for the children who has a longer disease course and makes a first visit.Combination of two methods is beneficial for the diagnosis and can be used for prediction of the disease outcome. Key words: FQ-PCR; Mycoplasmapneumoniae; MP-DNA; MP-IgM

Evaluation of 12 Commercial Tests and the Complement Fixation Test for Mycoplasma pneumoniae -Specific Immunoglobulin G (IgG) and IgM Antibodies, with PCR Used as the “Gold Standard”

Serology and nucleic acid amplification are the main diagnostic tools for the diagnosis of Mycoplasma pneumoniae infection. Since no reference standard is generally accepted, serologic assays for M. pneumoniae have not been evaluated on a broad scale. In this study, 12 commercially available serologic assays (for immunoglobulin G [IgG] and IgM) and the complement fixation test (CFT) were evaluated by using M. pneumoniae DNA detection by real-time PCR as the "gold standard." The assays tested were Platelia EIA (Bio-Rad), SeroMP EIA (Savyon), Serion classic EIA (Virion/Serion), Biotest EIA (Biotest), Ridascreen EIA (r-Biopharm), AniLabsystems EIA (Labsystems), Novum EIA (Novum Diagnostica), Diagnosys EIA (MP products), Genzyme/Virotech EIA, ImmunoWell EIA (Genbio), ImmunoCard EIA (Meridian), and SerodiaMycoII microparticle agglutination (Fujirebio). Serum samples (n = 46) from 27 PCR-positive patients with a known first day of disease and sera (n = 33) from PCR-negative controls were obtained from prospective studies of acute lower respiratory tract infections. Additionally, control sera (n = 63) from patients with acute viral or bacterial respiratory infections other than those caused by M. pneumoniae were tested. The results showed low specificities for both the Novum and the ImmunoCard IgM assays. The IgM assays with the best performances in terms of sensitivity and specificity were AniLabsystems (77% and 92%, respectively), SeroMP (71% and 88%, respectively), and CFT (65% and 97%, respectively). Good receiver operating characteristic areas under the curve were found for CFT (0.94), the Platelia assay (0.87), and the AniLabsystems assay (0.85). We conclude that there are few commercial serologic assays for the detection of M. pneumoniae infections with appropriate performances in terms of sensitivity and specificity and that PCR has become increasingly important for the diagnosis of M. pneumoniae infections in defined groups of patients.