Influencing factors and their diagnostic value of plastic bronchitis in children with refractory Mycoplasma pneumoniae pneumonia

Abstract

Objective: We aimed to investigate the influencing factors and diagnostic value of plastic bronchitis (PB) in children with refractory Mycoplasma pneumoniae (RMPP).

Methods: A retrospective analysis was conducted on 147 children diagnosed with RMPP between January 2022 and December 2024. Patients were divided into a PB group (n =32) and a Non-PB group (n = 115). General features, extrapulmonary manifestations, and laboratory parameters were compared. Independent risk factors for PB were identified by binary logistic regression. ROC curve and DeLong test were used to assess the predictive performance of CRP, LDH, and their combination.

Results: The PB group exhibited higher rates of fever duration > 10 days, wheeze, hypoxemia, atelectasis, and pleural effusion versus the Non-PB group (P < 0.05). Digestive, hematologic, mucocutaneous, and pleural complications were more frequent in PB cases (P < 0.05). Laboratory analyses revealed lower LY and elevated NEUT, CRP, LDH, ALT, AST, D-D, and Fibrinogen (Fg) in the PB group relative to the Non-PB group (P < 0.05). Binary logistic regression identified CRP and LDH as independent risk factors for PB in RMPP children (P < 0.05). Combined CRP+LDH showed superior predictive accuracy (AUC 0.911) compared to CRP (0.805) or LDH (0.824) alone (P < 0.05).

Conclusion: Elevated CRP and LDH levels are strong predictors for PB in children with RMPP, and their combined assessment offers higher diagnostic value.

Keywords: C-reactive protein; Children; Diagnostic value; Lactate dehydrogenase; Plastic bronchitis; Refractory mycoplasma pneumoniae.