2026-06-01 | Clinical features and risk factors of plastic bronchitis in Mycoplasma pneumoniae pneumonia children with pulmonary consolidation: a prospective cohort study.

To explore the clinical features and predictive factors of plastic bronchitis (PB) in children with Mycoplasma pneumoniae pneumonia (MPP) and pulmonary consolidation. Prospective observational study. Children with MPP and lung consolidation who were hospitalized and underwent bronchoscopy and treatment between January 1, 2024, and December 31, 2025, were enrolled as the study subjects. These subjects were divided into a PB group and a non-PB group. Demographic data, laboratory test results, and imaging findings were statistically analyzed to describe their clinical characteristics. Multivariate logistic regression analysis was performed to identify significant risk factors for PB in MPP children with pulmonary consolidation. A total of 65 PB patients and 115 non-PB patients were enrolled. The PB group showed higher rates of respiratory distress, longer hospital stays, longer fever durations, and elevated levels of neutrophil percentage, CRP, PCT, IL-6, LDH, SF, D-dimer, and ALT. Multivariate analysis identified fever duration (OR 6.777), D-dimer (OR 1.020), and LDH (OR 1.643) as significant predictors. Bootstrap validation demonstrated good model stability (corrected AUC 0.971, shrinkage factor 0.866). Optimal cutoffs were ≥7.5 days for fever duration, >0.94 μg/mL for D-dimer, and >400.5 U/L for LDH. Fever duration ≥7.5 days, D-dimer >0.94 μg/mL, and LDH >400.5 U/L are independently associated with PB in MPP children with pulmonary consolidation. These associations support a link between hypercoagulability, excessive inflammation, and PB. Further studies are needed to evaluate whether early anti-inflammatory therapy or bronchoscopic intervention improves clinical outcomes.

Open article ↗

2026-05-25 | Risk factors associated with plastic bronchitis in children with severe Mycoplasma pneumoniae pneumonia: a systematic review and meta-analysis.

Plastic bronchitis (PB) represents a severe complication of Mycoplasma pneumoniae pneumonia (MPP) in pediatric populations, characterized by the formation of obstructive bronchial casts. Early identification of risk factors is essential for timely bronchoscopic intervention and improved clinical outcomes. However, existing primary studies have reported inconsistent findings regarding the strength and significance of individual risk factors, likely attributable to heterogeneous study designs, varying predictor definitions and cut-off values, and differences in population severity criteria. No comprehensive meta-analysis has systematically synthesized this evidence to date. This study aimed to systematically evaluate and quantitatively synthesize evidence on risk factors associated with PB in children with severe (SMPP) or refractory (RMPP) MPP, with particular focus on inflammatory biomarkers, radiological features, and clinical characteristics. A systematic literature search was conducted across PubMed/MEDLINE, Embase, Web of Science, Scopus, and Cochrane Library (January 1, 2015, to December 1, 2025). Case-control and cohort studies reporting risk factors for bronchoscopically confirmed PB in pediatric SMPP or RMPP patients were included. Methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Random-effects meta-analysis was performed using the DerSimonian-Laird method with Hartung-Knapp adjustment. Effect sizes were expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Heterogeneity was quantified using I2 statistics, and publication bias was assessed via Egger's regression test. Twelve studies (8 retrospective cohort, 2 case-control, 1 prospective cohort, 1 cohort with external validation; NOS range: 6-8) comprising 4,406 children (1,123 PB cases) were included, all originating from China. A total of 38 effect sizes across 8 risk factor categories were extracted; all were multivariate-adjusted ORs. Risk factors significantly associated with PB included: lactate dehydrogenase (LDH) elevation (k=4, OR =4.06, 95% CI: 2.69-6.11, P=0.002), prolonged fever duration (k=4, OR =3.70, 95% CI: 1.12-12.26, P=0.040), D-dimer elevation (k=3, OR =2.63, 95% CI: 2.01-3.43, P=0.004), pleural effusion (k=4, OR =2.46, 95% CI: 1.55-3.91, P=0.009), atelectasis (k=4, OR =2.32, 95% CI: 1.61-3.34, P=0.005), and consolidation involving ≥2/3 lung lobe (k=2, OR =1.79, 95% CI: 1.36-2.37, P=0.02). Radiological risk factors and LDH demonstrated consistently low heterogeneity (I2=0%). One study reporting LDH as a continuous per-unit OR was excluded from the LDH pooled analysis due to scale incompatibility with dichotomized ORs. Substantial heterogeneity was observed for procalcitonin (PCT) (I2=77.8%) and fever duration (I2=47.5%). Elevated LDH, prolonged fever duration, D-dimer elevation, and specific radiological features (pleural effusion, atelectasis, consolidation) are significantly associated with increased risk of PB in pediatric SMPP. These risk factors may inform early clinical risk stratification and guide decision-making regarding bronchoscopic intervention. However, their predictive accuracy requires formal evaluation using discrimination metrics. Future prospective multicenter studies are warranted to develop and validate clinical prediction models incorporating these factors.

Open article ↗

2026-05-01 | D27-22 When a Cough Tells More Than a Story: A Rare Paraneoplastic Presentation in Pediatric Hodgkins Lymphoma

Abstract Introduction Plastic bronchitis (PB) and obliterative bronchiolitis (OB) are rare, severe pulmonary disorders in children, typically arising from distinct underlying etiologies. To date, there are no previous reports describing the coexistence of Hodgkin’s lymphoma with PB and OB prior to hematopoietic stem cell transplantation (HSCT). Case Presentation A 12-year-old girl presented with a 3-day history of fever, productive cough, and dyspnea. Her past medical history included classic Hodgkin’s lymphoma, nodular sclerosis subtype, stage IV, and was during OEPA-COPDAC chemotherapy (third cycle completed 20-days earlier). On admission, she was tachycardic, tachypneic, and hypoxic, with diminished breath sounds, bilateral wheezing, and forced expiration. Laboratory studies showed elevated inflammatory markers; blood and respiratory cultures, and FilmArray were negative. Chest X-ray revealed diffuse interstitial opacities. She received empirical broad-spectrum antibiotics for presumed pneumonia in an immunocompromised host, with partial improvement. Nine days later, fever recurred and respiratory symptoms persisted. HRCT demonstrated diffuse ground-glass opacities, some areas with a nodular appearance. Bronchoscopy and bronchoalveolar lavage were negative for infection, but tenacious, rubbery mucus casts were retrieved. Histology revealed mucoid material with sparse inflammatory cells, confirming plastic bronchitis. The patient’s mother later reported similar mucus expectoration 4-months before the oncologic diagnosis. Echocardiography showed mild pulmonary hypertension, and lymphangiography was unavailable. Cast expulsion ceased with treatment, and oxygen was successfully weaned. Subsequently, disease progression was confirmed, and salvage chemotherapy was initiated. The patient developed worsening cough and dyspnea with radiologic evidence of upper-lobe–predominant parenchymal progression. Lung biopsy revealed lymphohistiocytic inflammatory infiltrate with frequent polymorphonuclear neutrophils and fibroblastic plugs (organizing pneumonia). Pulmonary function tests showed decreased diffusing capacity (DLCO), increased lung volumes due to an increase in residual volume, and a normal flow-volume curve without significant response to the bronchodilator. OB was diagnosed, and therapy was optimized with inhaled dornase alfa, heparin, budesonide/formoterol, tiotropium, and azathioprine. Multidisciplinary consensus led to autologous HSCT. At day +383 post-transplant, she remained asymptomatic, without recurrence of bronchial casts, and with stable pulmonary function. Conclusion In children, PB is most commonly associated with Fontan physiology or infection, while OB typically follows infection, HSCT or lung transplantation. Only one pediatric case has linked PB to Hodgkin’s lymphoma as a paraneoplastic manifestation, possibly due to lymphatic obstruction from mediastinal disease. OB has also been described as a paraneoplastic or chemotherapy-related complication in adults. Given the rarity of these entities and limited therapeutic evidence, this case highlights the importance of multidisciplinary management and long-term follow-up. This abstract is funded by: None

Open article ↗

2026-05-01 | A61-07 Plastic Bronchitis in HbSC Sickle Cell Disease: Expanding the Pulmonary Complications Spectrum

Abstract Plastic bronchitis (PB) is a rare complication seen most commonly in children with congenital cardiac defects, asthma, or following respiratory infections. This condition has been reported in a few case reports and case series in children with sickle cell disease (SCD). While almost all of the cases reported have been in children with HbSS phenotype, there was one case series that included a patient with the HbSC variant. Studies show that clinical presentation of SCD is milder in those with HbSC variants, with significantly fewer episodes of acute chest syndrome than in those with the homozygous variant, HbSS. While the actual pathophysiology of PB in SCD is unclear, it is likely secondary to an interplay of multiple factors causing airway inflammation and impaired muco-ciliary clearance. In addition, impaired lymphatic drainage has been hypothesized to contribute to the pathogenesis of plastic bronchitis secondary to pulmonary hypertension attributable to pulmonary microvascular occlusion, hypoxic vasoconstriction or fat embolism during vaso-occlusive crisis. We aim to show the importance of identifying PB as a complication in children with HbSC variants where early initiation of aggressive airway clearance can minimize invasive procedures like bronchoscopy and potentially long-term morbidity. We report on a 10-year-old boy with HbSC SCD and recurrent episodes of plastic bronchitis with a restrictive pattern of lung disease on pulmonary function testing. He had his first episode of acute chest syndrome at 16 months of age with collapse of the right upper and middle lobe requiring a therapeutic bronchoscopy. Spirometry showed a restrictive pattern at 5 years of age. He was readmitted with another episode of acute chest when he was 10 years old with a collapse of the right middle and lower lobes, clinically worsening despite starting early antibiotics and aggressive airway clearance with chest physiotherapy, albuterol, hypertonic saline, and pulmozyme. Addition of mucomyst, incentive spirometry, cough assist along with high frequency chest wall oscillation and intrapulmonary percussive ventilation for 48 hours were able to clear mucus plugs, resulting in significant improvement on imaging. Lung function testing at follow-up showed a persistent restrictive lung pattern. Identifying these children can inform monitoring of their pulmonary function, ultimately helping to identify those at higher risk of organ damage and lung function decline. These patients could potentially benefit from treatment with drugs like hydroxyurea for which we have existing extensive data on to support its use and efficacy in the HbSS disease process. This abstract is funded by: None

Open article ↗

2026-05-01 | Viral Infection‐Associated Plastic Bronchitis Demonstrating Eosinophil Extracellular Trap Formation

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.

Open article ↗