Abstract / Summary
Abstract Background The objective of the research was to assess the exploratory predictors risk factors related to plastic bronchitis (PB) in pediatric patients presenting with severe Human bocavirus 1 (HBoV1) monoinfectious pneumonia. Methods Between December 2020 and December 2025, pediatric cases with severe monoinfectious HBoV1 pneumonia hospitalized at Fujian Children’s Hospital were enrolled in this study. Pediatric patients who presented with mixed infections, did not undergo bronchoscopy, had severe underlying diseases, or had incomplete clinical data were excluded from the analysis. According to bronchoscopic evaluation, cases were assigned into the non-PB group (n = 35) and the PB group (n = 16). Potential risk factors were determined by first analyzing differences in clinical presentations and laboratory findings across groups. The identification process utilized the least absolute shrinkage and selection operator (LASSO) regression together with Firth's penalized logistic regression. To assess the model’s stability, 1,000 bootstrap resamplings were then performed. Results Of 484 children initially examined for HBoV1 pneumonia, 51 with severe mono-HBoV1 infection were selected for the final analysis. Serum ferritin (SF), serum amyloid A (SAA), and D-dimer were markedly increased in the PB group. The combination of LASSO feature selection and Firth's penalized logistic regression identified SF (OR = 1.025, 95% CI: 1.010–1.046, P < 0.001), SAA (OR = 1.015, 95% CI: 1.003–1.052, P = 0.014), and D-dimer (OR = 2.247, 95% CI: 1.060–5.994, P = 0.036) as potential predicted factors for PB. Internal validation(1,000 bootstrap resamples) demonstrated good model discrimination, with an AUC of 0.952 (95% CI: 0.882–0.996). Conclusions Patients with HBoV1-associated PB have higher levels of SF, SAA, and D-dimer, suggesting tissue damage and hypercoagulative state in PB. These biomarkers may assist in the early identification of PB. Trial registration Not applicable.