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

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.

New Insights into the Epidemiological Characteristics of Mycoplasma pneumoniae Infection before and after the COVID-19 Pandemic

Mycoplasma pneumoniae (M. pneumoniae), a prevalent respiratory pathogen affecting children and adolescents, is known to trigger periodic global epidemics. The most recent significant outbreak commenced in the first half of 2023 and reached its peak globally during the autumn and winter months. Considering the worldwide repercussions of the COVID-19 pandemic, it has become increasingly essential to delve into the epidemiological characteristics of M. pneumoniae both before and after the pandemic. This review aims to provide a comprehensive analysis of the key features of M. pneumoniae epidemics in the pre-and post-COVID-19 contexts, including but not limited to shifts in the susceptible population, the molecular genotypes of the pathogen, the clinical manifestations, and potential new trends in drug resistance. Additionally, we will introduce the latest advancements in the diagnosis of M. pneumoniae.

Application value of antibody titres and RNA detection in the early prediction of Mycoplasma pneumoniae pneumonia in children: a retrospective study

BACKGROUND

Children with Mycoplasma pneumoniae pneumonia (MPP) are prone to a missed diagnosis at the early stages of the disease, which greatly affects the prognosis of children. In this study, the application value of Mycoplasma pneumoniae (MP) antibody titres and RNA detection for diagnosing MP infection in children with community-acquired pneumonia (CAP) was evaluated. The present study aimed to seek appropriate detection methods and strategies for early rapid diagnosis in children with MPP.

METHODS

A retrospective study was conducted on 563 paediatric patients aged 1 month to 15 years with CAP who were admitted to Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology between July 2021 and February 2022. In all patients, throat swabs were collected for MP-RNA detection (simultaneous amplification and testing, SAT), and paired serum samples were collected for MP total antibody detection (particle agglutination, PA).

RESULTS

The classification as MPP or non-MPP was based on clinical diagnosis, serum MP antibody titre, and clinical or laboratory evidence of infection by other pathogen(s). Among the 563 patients with pneumonia, 187 patients were in the MPP group, and 376 patients were in the non-MPP group. The Kappa values between the particle agglutination test at different titres (1:80, 1:160) and MP-RNA detection were 0.612 and 0.660 (P<0.01), and the consistency of the three methods was acceptable. When the single screening method was used, MP-RNA had the highest sensitivity (93.05%), while PA (1:160) had the highest specificity (100%). PA (1:80), with an area under the curve (AUC) of 0.822, was better than PA (1:160), with an AUC of 0.783, and there was a significant difference. When the combined screening methods were used, the AUC of MP-RNA parallel PA (1:160) was significantly higher than that of titres (1:80) (z=-4.906, P < 0.01). Except for MP-80, the efficacy of the other three test methods in females was slightly better than that in males. Among the differences in age distribution, PA (1:80) was slightly less effective in the 13-72 months age group than at other ages, and MP-RNA parallel PA (1:160) was slightly better than the younger age group (≤ 36 m). In the older age group (> 36 m), PA (1:160) was just the opposite, while MP-RNA was slightly better than other age groups in the 13-72 months age group.

CONCLUSIONS

For the diagnosis of MPP in children at the early of the disease, the antibody titre (1:160) parallel MP-RNA should be given preference, and then the disease should be further classified according to the antibody titre level and the age of the child. The combined application of the two detection methods could complement each other and strengthen the advantages, providing reliable laboratory evidence for the clinical diagnosis and timely treatment of MPP. When using the PA method alone to provide a reference standard to clarify MP infection, the differential diagnosis ability of 1:80 for MPP is better than 1:160, especially for children younger than 36 months.