Objective This study aimed to assess the consistency of Mycoplasma pneumoniae (MP)-DNA load in the respiratory tracts, its correlation with Mycoplasma pneumoniae pneumonia (MPP) manifestations, and its predictive value for refractory Mycoplasma pneumoniae pneumonia (RMPP).

Methods A retrospective study was performed on a cohort of MPP cases, including 215 patients with positive nasopharyngeal aspirate (NPA) MP-DNA and 59 with positive bronchoalveolar lavage fluid (BALF) MP-DNA. Patients were categorized into two groups based on MP-DNA load: low load (≤106/mL) and high load (>106/mL). The consistency of MP-DNA load in NPA and BALF was determined by Spearman's correlation coefficient. Clinical, laboratory, and radiological data were compared, and the predictive value of NPA MP-DNA for RMPP was evaluated using the receiver operating characteristic curve.

Results A strong correlation was observed between NPA and BALF MP-DNA. High-load groups in both had longer fever durations and more pronounced increases in C-reactive protein, lactate dehydrogenase, and ferritin (p < 0.05). Routine-dose glucocorticoids were more required for patients exhibiting high MP-DNA loads, regardless of the source of the sample. The area under the curve for predicting RMPP using NPA MP-DNA load was 0.861, with 92.9% sensitivity and 67.9% specificity at a cutoff of 9.5 × 105/mL.

Conclusion The NPA MP-DNA load reflects the severity of pulmonary inflammatory response. Increased MP-DNA load in both the upper and lower airways is associated with longer fever and increased inflammation, indicating a need for glucocorticoid therapy. NPA MP-DNA can predict RMPP with high sensitivity.

C.Y. contributed to the study conception and design; Z.M. and L.X.Q. to the data collection; C.Q. and C.L. to resources; H.R. to the statistical analysis; and C.Y. and L.C.X to writing. All authors reviewed the results and approved the final version of the article.

The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.

Received: 25 April 2024

Accepted: 04 October 2024

Article published online:
11 December 2024

© 2024. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany