Neutrophil extracellular traps and severe mycoplasma pneumonia: A clinical observational study

This full-scale confirmatory study aimed to measure serum neutrophil extracellular traps (NETs) levels in children with severe Mycoplasma pneumoniae pneumonia (SMPP) and non-severe MPP, and to compare the predictive performance of serum NETs, C-reactive protein (CRP), and lactate dehydrogenase (LDH) for SMPP.

A total of 200 children hospitalized with MPP between January 2023 and August 2024 were consecutively enrolled and divided into SMPP (n = 100) and non-severe MPP (n = 100) groups. Baseline demographic and laboratory indices were compared between groups. Receiver operating characteristic (ROC) curves were used to assess predictive value, and univariate and multivariate logistic regression were performed to identify independent predictors of SMPP.

Age and sex distributions were comparable between groups (all P > .05). Serum white blood cell count, neutrophil ratio, CRP, D-dimer, LDH, and NETs were significantly higher in the SMPP group (all P < .001). ROC analysis showed serum NETs had the highest area under the curve (AUC = 0.83, 95% confidence interval [CI]: 0.762-0.896), with a cutoff value of 19.2, sensitivity 0.818, and specificity 0.835. Multivariate logistic regression confirmed serum NETs (odds ratio [OR] = 4.32, 95% CI: 3.45-7.25, P = .023), CRP (OR = 3.62, 95% CI: 1.85-9.25, P = .010), and LDH (OR = 1.63, 95% CI: 1.18-2.26, P = .001) as independent predictors of SMPP.

Serum NETs are strongly elevated in children with SMPP and show better predictive performance than conventional CRP and LDH. Combined measurement of NETs, CRP, and LDH provides a reliable tool for the early identification of pediatric SMPP. This study extends and validates our preliminary exploratory findings with a larger sample and complete statistical analysis.