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) < 10(5) (54 cases), ≥10(5) and <10(6) (71 cases), ≥10(6) and <10(7) (112 cases), ≥10(7) and ≤10(8) (114 cases), and >10(8) (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.