Expansion of Phenotypically Altered Dendritic Cell Populations in the Small Airways and Alveolar Parenchyma in Patients with Chronic Obstructive Pulmonary Disease

Contrasting the antigen-presenting dendritic cells (DCs) in the conducting airways, the alveolar DC populations in human lungs have remained poorly investigated. Consequently, little is known about how alveolar DCs are altered in diseases such as chronic obstructive pulmonary disease (COPD). This study maps multiple tissue DC categories in the distal lung across COPD severities. Specifically, single-multiplex immunohistochemistry was applied to quantify langerin/CD207+, CD1a+, BDCA2+, and CD11c+ subsets in distal lung compartments from patients with COPD (GOLD stage I-IV) and never-smoking and smoking controls. In the alveolar parenchyma, increased numbers of CD1a+langerin- (p < 0.05) and BDCA-2+ DCs (p < 0.001) were observed in advanced COPD compared with controls. Alveolar CD11c+ DCs also increased in advanced COPD (p < 0.01). In small airways, langerin+ and BDCA-2+ DCs were also significantly increased. Contrasting the small airway DCs, most alveolar DC subsets frequently extended luminal protrusions. Importantly, alveolar and small airway langerin+ DCs in COPD lungs displayed site-specific marker profiles. Further, multiplex immunohistochemistry with single-cell quantification was used to specifically profile langerin DCs and reveal site-specific expression patterns of the maturation and activation markers S100, fascin, MHC2, and B7. Taken together, our results show that clinically advanced COPD is associated with increased levels of multiple alveolar DC populations exhibiting features of both adaptive and innate immunity phenotypes. This expansion is likely to contribute to the distal lung immunopathology in COPD patients.

Flexible bronchoscopy-guided microwave ablation in peripheral porcine lung: a new minimally-invasive ablation

Background

Transbronchial lung biopsy is an important approach to diagnose peripheral lung cancer, but bronchoscopy based treatment options are limited and poorly studied. A flexible bronchoscopy-guided water-cooled microwave ablation (MWA) catheter was developed to evaluate the feasibility and safety both in ex vivo and in vivo porcine models.

Methods

Using direct penetration of the catheter through the surface of ex vivo porcine lung, ablations (n=9) were performed at 70, 80, 90 W for 10 minutes. Temperatures of the catheter and 10, 15, 20 mm away from the tip were measured. Under bronchoscopy conditions in porcine lung, ablations (n=18, 6 in ex vivo and 12 in vivo) were performed at 80 W for 5 minutes. Computed tomography (CT) was acquired perioperative, 24 hours, 2 weeks, and 4 weeks post ablation. Ablation zones were excised at 24 hours and 4 weeks respectively. Long-axis diameter (Dl) and short-axis diameter (Ds) were measured and tissues were sectioned for pathological examination.

Results

In-ex vivo lung, the temperature at 20 mm removed was over 60 °C at 80 W for 288±26 seconds. The ablations under bronchoscopic conditions were successful in-ex vivo and in vivo lung. No complications occurred during the procedures. Coagulation necrosis was visible at 24 hours, and repaired fibrous tissue was seen at 4 weeks.

Conclusions

The flexible bronchoscopy-guided water-cooled MWA is feasible and safe. This early animal data holds promise of MWA becoming a potential therapeutic tool for Peripheral Lung Cancers.