Retrospective study identifies CRP, pleural effusion, and LDH as risk factors for plastic bronchitis in children with refractory M. pneumoniae pneumonia

A retrospective cohort study analyzed 205 hospitalized children diagnosed with refractory Mycoplasma pneumoniae pneumonia (RMPP) at two tertiary hospitals to identify risk factors for plastic bronchitis (PB). The study found that 52 patients (25.4% of the cohort) developed PB. Researchers developed a nomogram prediction model indicating three risk factors associated with PB development: C-reactive protein (CRP) levels > 20 mg/L, presence of pleural effusion, and high lactate dehydrogenase (LDH) levels.

The prediction model demonstrated an area under the receiver operating characteristic curve (AUC) of 0.783 (95% CI: 0.71–0.86), suggesting moderate discriminatory ability. The Hosmer–Lemeshow goodness-of-fit test showed a P-value of 0.408, indicating adequate model calibration. No specific intervention or exposure was reported, and the comparator group consisted of children with RMPP who did not develop PB.

Safety and tolerability data were not reported in this retrospective analysis. The study has several limitations: it was observational and retrospective in design, conducted at only two tertiary centers, and did not report follow-up duration. The model identifies statistical associations for risk prediction but does not establish causation or confirm PB diagnosis. Funding sources and conflicts of interest were not reported.

For clinical practice, these findings suggest that in children with RMPP, clinicians might consider monitoring CRP levels, checking for pleural effusion, and assessing LDH levels as potential indicators of increased PB risk. However, given the observational nature and moderate predictive performance of the model, these factors should not replace clinical judgment or definitive diagnostic procedures like bronchoscopy when indicated.