Exploring the link between a novel approach for computer aided lung sound analysis and imaging biomarkers: a cross-sectional study.

BACKGROUND: Computer Aided Lung Sound Analysis (CALSA) aims to overcome limitations associated with standard lung auscultation by removing the subjective component and allowing quantification of sound characteristics. In this proof-of-concept study, a novel automated approach was evaluated in real patient data by comparing lung sound characteristics to structural and functional imaging biomarkers. METHODS: Patients with cystic fibrosis (CF) aged > 5y were recruited in a prospective cross-sectional study. CT scans were analyzed by the CF-CT scoring method and Functional Respiratory Imaging (FRI). A digital stethoscope was used to record lung sounds at six chest locations. Following sound characteristics were determined: expiration-to-inspiration (E/I) signal power ratios within different frequency ranges, number of crackles per respiratory phase and wheeze parameters. Linear mixed-effects models were computed to relate CALSA parameters to imaging biomarkers on a lobar level. RESULTS: 222 recordings from 25 CF patients were included. Significant associations were found between E/I ratios and structural abnormalities, of which the ratio between 200 and 400 Hz appeared to be most clinically relevant due to its relation with bronchiectasis, mucus plugging, bronchial wall thickening and air trapping on CT. The number of crackles was also associated with multiple structural abnormalities as well as regional airway resistance determined by FRI. Wheeze parameters were not considered in the statistical analysis, since wheezing was detected in only one recording. CONCLUSIONS: The present study is the first to investigate associations between auscultatory findings and imaging biomarkers, which are considered the gold standard to evaluate the respiratory system. Despite the exploratory nature of this study, the results showed various meaningful associations that highlight the potential value of automated CALSA as a novel non-invasive outcome measure in future research and clinical practice.

Correlation between early postnatal body weight changes and lung ultrasound scores as predictors of bronchopulmonary dysplasia in preterm infants: A secondary analysis of a prospective study.

Recent research links early weight changes (EWC) with bronchopulmonary dysplasia (BPD) in preterm neonates, while lung ultrasound score (LUS) has shown promise in predicting BPD. We aimed to explore the correlation between LUS and EWC as markers of extravascular lung edema and to investigate the correlation between LUS and EWC in preterm infants with respiratory distress syndrome regarding future BPD development. This secondary analysis of a prospective study involved infants ≤ 28 weeks gestation. Enrolled infants underwent lung ultrasound assessment on postnatal days 3, 7 and 14, measuring LUS. EWC was computed on the same time points. Infants were classified as either having BPD or not. Descriptive statistics, correlation coefficient, and area under the receiver operating characteristic (AUROC) curve analysis were utilized. Of 132 infants, 70 (53%) had BPD. Univariate analysis revealed statistically significant differences in LUS and EWC at days 3, 7, and 14 between BPD and no-BPD groups (p < 0.001). A statistically significant but weak positive correlation existed between LUS and EWC (r0.37, r0.29, r0.24, and p < 0.01) at postnatal days 3, 7, and 14, respectively. AUROC analysis indicated LUS having superior predictive capacity for the need for invasive mechanical ventilation at day 14 as well as the later BPD development compared to EWC (p < 0.0001). CONCLUSION: In a cohort of extreme preterm infants, our study revealed a positive yet weak correlation between LUS and EWC, suggesting that EWC was not the major contributing to the evolving chronic lung disease. WHAT IS KNOWN: • Recent evidence links Early Weight-Changes with bronchopulmonary dysplasia in preterm neonates. • Lung ultrasound score has shown promise in early prediction of the subsequent development of bronchopulmonary dysplasia in preterm infants. No studies have examined the correlation between Early Weight-Changes and Lung ultrasound score in preterm infants during first 2 weeks after birth. WHAT IS NEW: • Our study demonstrated a positive and statistically significant correlation between early LUS and EWC, indicating their potential role as early predictors for the subsequent development of BPD in extreme preterm infants. • The weak correlation between the two parameters may stem from the possible restricted influence of EWC, given that it may not be the primary factor contributing to the evolving chronic lung disease.

Clinical Implications of Removing Race-Corrected Pulmonary Function Tests for African American Patients Requiring Surgery for Lung Cancer.

Importance: Removal of race correction in pulmonary function tests (PFTs) is a priority, given that race correction inappropriately conflates race, a social construct, with biological differences and falsely assumes worse lung function in African American than White individuals. However, the impact of decorrecting PFTs for African American patients with lung cancer is unknown. Objectives: To identify how many hospitals providing lung cancer surgery use race correction, examine the association of race correction with predicted lung function, and test the effect of decorrection on surgeons' treatment recommendations. Design, Setting, and Participants: In this quality improvement study, hospitals participating in a statewide quality collaborative were contacted to determine use of race correction in PFTs. For hospitals performing race correction, percent predicted preoperative and postoperative forced expiratory volume in 1 second (FEV1) was calculated for African American patients who underwent lung cancer resection between January 1, 2015, and September 31, 2022, using race-corrected and race-neutral equations. US cardiothoracic surgeons were then randomized to receive 1 clinical vignette that differed by the use of Global Lung Function Initiative equations for (1) African American patients (percent predicted postoperative FEV1, 49%), (2) other race or multiracial patients (percent predicted postoperative FEV1, 45%), and (3) race-neutral patients (percent predicted postoperative FEV1, 42%). Main Outcomes and Measures: Number of hospitals using race correction in PFTs, change in preoperative and postoperative FEV1 estimates based on race-neutral or race-corrected equations, and surgeon treatment recommendations for clinical vignettes. Results: A total of 515 African American patients (308 [59.8%] female; mean [SD] age, 66.2 [9.4] years) were included in the study. Fifteen of the 16 hospitals (93.8%) performing lung cancer resection for African American patients during the study period reported using race correction, which corresponds to 473 African American patients (91.8%) having race-corrected PFTs. Among these patients, the percent predicted preoperative FEV1 and postoperative FEV1 would have decreased by 9.2% (95% CI, -9.0% to -9.5%; P < .001) and 7.6% (95% CI, -7.3% to -7.9%; P < .001), respectively, if race-neutral equations had been used. A total of 225 surgeons (194 male [87.8%]; mean [SD] time in practice, 19.4 [11.3] years) were successfully randomized and completed the vignette items regarding risk perception and treatment outcomes (76% completion rate). Surgeons randomized to the vignette with African American race-corrected PFTs were more likely to recommend lobectomy (79.2%; 95% CI, 69.8%-88.5%) compared with surgeons randomized to the other race or multiracial-corrected (61.7%; 95% CI, 51.1%-72.3%; P = .02) or race-neutral PFTs (52.8%; 95% CI, 41.2%-64.3%; P = .001). Conclusions and Relevance: Given the findings of this quality improvement study, surgeons should be aware of changes in PFT testing because removal of race correction PFTs may change surgeons' treatment decisions and potentially worsen existing disparities in receipt of lung cancer surgery among African American patients.

Longitudinal Follow-Up of Participants With Tobacco Exposure and Preserved Spirometry.

Importance: People who smoked cigarettes may experience respiratory symptoms without spirometric airflow obstruction. These individuals are typically excluded from chronic obstructive pulmonary disease (COPD) trials and lack evidence-based therapies. Objective: To define the natural history of persons with tobacco exposure and preserved spirometry (TEPS) and symptoms (symptomatic TEPS). Design, Setting, and Participants: SPIROMICS II was an extension of SPIROMICS I, a multicenter study of persons aged 40 to 80 years who smoked cigarettes (>20 pack-years) with or without COPD and controls without tobacco exposure or airflow obstruction. Participants were enrolled in SPIROMICS I and II from November 10, 2010, through July 31, 2015, and followed up through July 31, 2021. Exposures: Participants in SPIROMICS I underwent spirometry, 6-minute walk distance testing, assessment of respiratory symptoms, and computed tomography of the chest at yearly visits for 3 to 4 years. Participants in SPIROMICS II had 1 additional in-person visit 5 to 7 years after enrollment in SPIROMICS I. Respiratory symptoms were assessed with the COPD Assessment Test (range, 0 to 40; higher scores indicate more severe symptoms). Participants with symptomatic TEPS had normal spirometry (postbronchodilator ratio of forced expiratory volume in the first second [FEV1] to forced vital capacity >0.70) and COPD Assessment Test scores of 10 or greater. Participants with asymptomatic TEPS had normal spirometry and COPD Assessment Test scores of less than 10. Patient-reported respiratory symptoms and exacerbations were assessed every 4 months via phone calls. Main Outcomes and Measures: The primary outcome was assessment for accelerated decline in lung function (FEV1) in participants with symptomatic TEPS vs asymptomatic TEPS. Secondary outcomes included development of COPD defined by spirometry, respiratory symptoms, rates of respiratory exacerbations, and progression of computed tomographic-defined airway wall thickening or emphysema. Results: Of 1397 study participants, 226 had symptomatic TEPS (mean age, 60.1 [SD, 9.8] years; 134 were women [59%]) and 269 had asymptomatic TEPS (mean age, 63.1 [SD, 9.1] years; 134 were women [50%]). At a median follow-up of 5.76 years, the decline in FEV1 was -31.3 mL/y for participants with symptomatic TEPS vs -38.8 mL/y for those with asymptomatic TEPS (between-group difference, -7.5 mL/y [95% CI, -16.6 to 1.6 mL/y]). The cumulative incidence of COPD was 33.0% among participants with symptomatic TEPS vs 31.6% among those with asymptomatic TEPS (hazard ratio, 1.05 [95% CI, 0.76 to 1.46]). Participants with symptomatic TEPS had significantly more respiratory exacerbations than those with asymptomatic TEPS (0.23 vs 0.08 exacerbations per person-year, respectively; rate ratio, 2.38 [95% CI, 1.71 to 3.31], P < .001). Conclusions and Relevance: Participants with symptomatic TEPS did not have accelerated rates of decline in FEV1 or increased incidence of COPD vs those with asymptomatic TEPS, but participants with symptomatic TEPS did experience significantly more respiratory exacerbations over a median follow-up of 5.8 years.

O uso de métodos contraceptivos hormonais em pacientes com asma: repercussões clínicas / The use of hormonal contraceptives methods in patients with asthma: clinical repercussions

Objetivo: Analisar o uso dos contraceptivos hormonais em mulheres com asma e a escolha desses métodos contraceptivos para essa população, com avaliação de eventuais repercussões sobre novos episódios de asma e sibilos. Métodos: Foram selecionados estudos longitudinais, ensaios clínicos, revisões sistemáticas e metanálises. As plataformas consultadas foram PubMed, Embase, Cochrane e SciELO, com a utilização dos descritores: "contracepção", "contracepção hormonal", "sistema intrauterino liberador de levonorgestrel" e "asma". Resultados: Dois grandes estudos demonstraram que o uso de contraceptivos hormonais esteve associado à redução do risco de novos episódios de asma. Uma revisão sistemática concluiu que os resultados para o uso de contraceptivos hormonais para mulheres com asma foram mistos, com aumento ou redução dos seguintes riscos: novo episódio de asma e aumento da frequência das crises e dos sibilos. O uso da contracepção hormonal em pacientes obesas portadoras de asma é controverso. Conclusão: Os resultados para o uso de contraceptivos hormonais em mulheres com asma são inconsistentes, com relatos de aumento ou de redução do risco de novos episódios. O uso do método contraceptivo deve ser discutido individualmente, levando-se em consideração outros fatores de risco associados e o desejo da mulher. A paciente deverá ser orientada se houver piora dos sintomas clínicos de asma na vigência do uso de qualquer método contraceptivo hormonal.

Objective: To analyze the use of hormonal contraceptives in women with asthma and the choice of this contraceptive method for this population, evaluating possible repercussions on new episodes of asthma and wheezing. Methods: Longitudinal studies, clinical trials, systematic reviews and meta-analyses were selected. Platforms consulted: PubMed, Embase, Cochrane, SciELO, using the descriptors: "contraception", "hormonal contraception", "levonorgestrel-releasing intrauterine system" and "asthma". Results: Two large studies demonstrated that the use of hormonal contraceptives was associated with a reduced risk of new episodes of asthma. A systematic review concluded that the results for the use of hormonal contraceptives for women with asthma were mixed, with increased or decrease in the following risks: new asthma episodes, increased frequency and wheezing. The use of hormonal contraception in obese patients with asthma is controversial. Conclusion: The results for the use of hormonal contraceptives in women with asthma are inconsistent, with reports of increased or reduced risk of new episodes. The use of the contraceptive method should be discussed individually, taking into account other associated risk factors and the woman's desire. The patient will be advised if there is a worsening of the clinical symptoms of asthma while using any hormonal contraceptive method.

Respiratory Invariant Textures From Static Computed Tomography Scans for Explainable Lung Function Characterization.

PURPOSE: The inherent characteristics of lung tissue independent of breathing maneuvers may provide fundamental information for function assessment. This paper attempted to correlate textural signatures from computed tomography (CT) with pulmonary function measurements. MATERIALS AND METHODS: Twenty-one lung cancer patients with thoracic 4-dimensional CT, DTPA-single-photon emission CT ventilation ( VNM ) scans, and available spirometry measurements (forced expiratory volume in 1 s, FEV 1 ; forced vital capacity, FVC; and FEV 1 /FVC) were collected. In subregional feature discovery, function-correlated candidates were identified from 79 radiomic features based on the statistical strength to differentiate defected/nondefected lung regions. Feature maps (FMs) of selected candidates were generated on 4-dimensional CT phases for a voxel-wise feature distribution study. Quantitative metrics were applied for validations, including the Spearman correlation coefficient (SCC) and the Dice similarity coefficient for FM- VNM spatial agreement assessments, intraclass correlation coefficient for FM interphase robustness evaluations, and FM-spirometry comparisons. RESULTS: At the subregion level, 8 function-correlated features were identified (effect size>0.330). The FMs of candidates yielded moderate-to-strong voxel-wise correlations with the reference VNM . The FMs of gray level dependence matrix dependence nonuniformity showed the highest robust (intraclass correlation coefficient=0.96 and P <0.0001) spatial correlation, with median SCCs ranging from 0.54 to 0.59 throughout the 10 breathing phases. Its phase-averaged FM achieved a median SCC of 0.60, a median Dice similarity coefficient of 0.60 (0.65) for high (low) functional lung volumes, and a correlation of 0.565 (0.646) between the spatially averaged feature values and FEV 1 (FEV 1 /FVC). CONCLUSIONS: The results provide further insight into the underlying association of specific pulmonary textures with both local ( VNM ) and global (FEV 1 /FVC, FEV 1 ) functions. Further validations of the FM generalizability and the standardization of implementation protocols are warranted before clinically relevant investigations.

Ziritaxestat, a Novel Autotaxin Inhibitor, and Lung Function in Idiopathic Pulmonary Fibrosis: The ISABELA 1 and 2 Randomized Clinical Trials.

Importance: There is a major need for effective, well-tolerated treatments for idiopathic pulmonary fibrosis (IPF). Objective: To assess the efficacy and safety of the autotaxin inhibitor ziritaxestat in patients with IPF. Design, Setting, and Participants: The 2 identically designed, phase 3, randomized clinical trials, ISABELA 1 and ISABELA 2, were conducted in Africa, Asia-Pacific region, Europe, Latin America, the Middle East, and North America (26 countries). A total of 1306 patients with IPF were randomized (525 patients at 106 sites in ISABELA 1 and 781 patients at 121 sites in ISABELA 2). Enrollment began in November 2018 in both trials and follow-up was completed early due to study termination on April 12, 2021, for ISABELA 1 and on March 30, 2021, for ISABELA 2. Interventions: Patients were randomized 1:1:1 to receive 600 mg of oral ziritaxestat, 200 mg of ziritaxestat, or placebo once daily in addition to local standard of care (pirfenidone, nintedanib, or neither) for at least 52 weeks. Main Outcomes and Measures: The primary outcome was the annual rate of decline for forced vital capacity (FVC) at week 52. The key secondary outcomes were disease progression, time to first respiratory-related hospitalization, and change from baseline in St George's Respiratory Questionnaire total score (range, 0 to 100; higher scores indicate poorer health-related quality of life). Results: At the time of study termination, 525 patients were randomized in ISABELA 1 and 781 patients in ISABELA 2 (mean age: 70.0 [SD, 7.2] years in ISABELA 1 and 69.8 [SD, 7.1] years in ISABELA 2; male: 82.4% and 81.2%, respectively). The trials were terminated early after an independent data and safety monitoring committee concluded that the benefit to risk profile of ziritaxestat no longer supported their continuation. Ziritaxestat did not improve the annual rate of FVC decline vs placebo in either study. In ISABELA 1, the least-squares mean annual rate of FVC decline was -124.6 mL (95% CI, -178.0 to -71.2 mL) with 600 mg of ziritaxestat vs -147.3 mL (95% CI, -199.8 to -94.7 mL) with placebo (between-group difference, 22.7 mL [95% CI, -52.3 to 97.6 mL]), and -173.9 mL (95% CI, -225.7 to -122.2 mL) with 200 mg of ziritaxestat (between-group difference vs placebo, -26.7 mL [95% CI, -100.5 to 47.1 mL]). In ISABELA 2, the least-squares mean annual rate of FVC decline was -173.8 mL (95% CI, -209.2 to -138.4 mL) with 600 mg of ziritaxestat vs -176.6 mL (95% CI, -211.4 to -141.8 mL) with placebo (between-group difference, 2.8 mL [95% CI, -46.9 to 52.4 mL]) and -174.9 mL (95% CI, -209.5 to -140.2 mL) with 200 mg of ziritaxestat (between-group difference vs placebo, 1.7 mL [95% CI, -47.4 to 50.8 mL]). There was no benefit with ziritaxestat vs placebo for the key secondary outcomes. In ISABELA 1, all-cause mortality was 8.0% with 600 mg of ziritaxestat, 4.6% with 200 mg of ziritaxestat, and 6.3% with placebo; in ISABELA 2, it was 9.3% with 600 mg of ziritaxestat, 8.5% with 200 mg of ziritaxestat, and 4.7% with placebo. Conclusions and Relevance: Ziritaxestat did not improve clinical outcomes compared with placebo in patients with IPF receiving standard of care treatment with pirfenidone or nintedanib or in those not receiving standard of care treatment. Trial Registration: ClinicalTrials.gov Identifiers: NCT03711162 and NCT03733444.

Cross-sectional and Longitudinal Associations Between Propylene Oxide Exposure and Lung Function Among Chinese Community Residents: Roles of Oxidative DNA Damage, Lipid Peroxidation, and Protein Carbonylation.

BACKGROUND: Toxicologic studies have reported propylene oxide (PO) exposure may harm the respiratory system, but the association between PO exposure and lung function and potential mechanism remains unclear. RESEARCH QUESTION: What is the association between PO exposure and lung function and potential mediating mechanism? STUDY DESIGN AND METHODS: Urinary PO metabolite [N-Acetyl-S-(2-hydroxypropyl)-L-cysteine (2HPMA)] as PO internal exposure biomarker and lung function were measured for 3,692 community residents at baseline and repeated at 3-year follow up. Cross-sectional and longitudinal associations between urinary 2HPMA and lung function were assessed by linear mixed model. Urinary 8-hydroxy-deoxyguanosine, urinary 8-iso-prostaglandin-F2α, and plasma protein carbonyls as biomarkers of oxidative DNA damage, lipid peroxidation, and protein carbonylation, respectively, were measured for all participants to explore their potential roles in 2HPMA-associated lung function decline by mediation analysis. RESULTS: After adjustment for potential covariates, each threefold increase in urinary 2HPMA was cross sectionally associated with a 26.18 mL (95% CI, -50.55 to -1.81) and a 21.83 mL (95% CI, -42.71 to -0.95) decrease in FVC and FEV1, respectively, at baseline (all P < .05). After 3 years of follow up, 2HPMA was observed to be longitudinally associated with FEV1/FVC decline. No significant interaction effect of smoking or passive smoking was observed (Pinteraction > .05), and the associations between 2HPMA and lung function indexes were persistent among participants who were not smoking and those who were not passive smoking in both baseline and follow-up evaluations. We observed urinary 8-hydroxy-deoxyguanosine partially mediated the associations of 2HPMA with FVC (mediation proportion, 5.48%) and FEV1 (mediation proportion, 6.81%), and plasma protein carbonyl partially mediated the association between 2HPMA and FEV1 (mediation proportion, 3.44%). INTERPRETATION: PO exposure was associated with lung function decline among community residents, and oxidative DNA damage and protein carbonylation partially mediated PO exposure-associated lung function decline. Further attention on respiratory damage caused by PO exposure is warranted.

Radiation pneumonitis in relation to pulmonary function, dosimetric factors, TGFß1 expression, and quality of life in breast cancer patients receiving post-operative radiotherapy: a prospective 6-month follow-up study.

PURPOSE: To investigate development of radiation pneumonitis (RP) in relation to pulmonary function, dosimetric factors, and transforming growth factor beta-1 (TGFß1) expression in irradiated breast cancer patients. METHODS: A total of 49 breast cancer patients who received post-operative radiotherapy (RT) were evaluated in terms of pulmonary function tests (PFTs), quality of life (QoL), development of RP, dosimetric factors, cytokine levels, and lung high-resolution computed tomography (HRCT) before and after RT. ROC analysis was performed for performance of dosimetric factors in predicting RP, while frequencies of single nucleotide polymorphisms (SNPs) genotyped for TGFß1 (rs11466345 and rs1800470) were also evaluated. RESULTS: All cases with RP (10.2%) recovered clinically at the end of third post-RT month. PFT and HRCT parameters were similar before and after RT overall, as well as by RP and the radiation field subgroups. ROC analysis revealed the significant role of the ipsilateral V5 (cutoff value of 45.9%, p = 0.039), V10 (29.4%, p = 0.015), V20 (23%, p = 0.017), and MLD (1200 cGy, p = 0.030) in predicting RP. Higher post-RT TGFß1 levels (p = 0.037) were noted overall and in patients with RP. Patient and control groups were similar in terms of frequencies of SNPs genotyped for TGFß1 (rs11466345 and rs1800470). EORTC QLQ-C30 and QLQ-BR-23 scores were similar in patients with vs. without RP. CONCLUSION: Our findings revealed significant role of dosimetric factors including MLD, V20 as well as the low dose-volume metrics in predicting the risk of RP among breast cancer patients who received post-operative RT. Implementation of RT, extent of radiation field or the presence of RP had no significant impact on PFTs.

Assessing the health risk of living near composting facilities on lung health, fungal and bacterial disease in cystic fibrosis: a UK CF Registry study.

AIM: To explore the health risk of living near permitted composting sites (PCSs) on disease severity in children and adults with cystic fibrosis (CF) across the UK.  METHODS: A semi-individual cross-sectional study was used to examine the risk of disease severity in people with CF (pwCF) within and beyond 4 km of PCSs in the UK in 2016. All pwCF registered in the UK CF Registry were eligible for this study. Linear and Poisson regressions, adjusted for age, gender, genotype, BMI, Pseudomonas aeruginosa and deprivation, were used to quantify associations between distance to a PCS and percent predicted forced expiratory volume in one second (ppFEV1), pulmonary exacerbations (#IVdays), and fungal and bacterial infections. RESULTS: The mean age of the 9,361 pwCF (3,931 children and 5,430 adults) studied was 20.1 (SD = 14.1) years; 53.3% were male; and 49.2% were homozygous F508del. Over 10% of pwCF (n = 1,015) lived within 4 km of a PCS. We found no statistically significant difference in ppFEV1 and #IVdays/year in children. However, in adults, ppFEV1 was -1.07% lower (95% confidence interval (CI): -2.29%, 0.16%) and #IVdays/year were 1.02 day higher (95%CI: 1.01, 1.04) within 4 km of a PCS. Furthermore, there were statistically significant differences in mean ppFEV1 in CF adults with Aspergillus fumigatus (58.2.% vs 62.0%, p = 0.005) and Candida spp. (56.9% vs 59.9%, p = 0.029) residing within 4 km of a PCS. No associations were identified for allergic bronchopulmonary aspergillosis, P. aeruginosa or Staphylococcus aureus. CONCLUSIONS: This novel national study provides evidence that adults with CF living near a PCS may experience small reductions in lung function, an increased risk of pulmonary exacerbations, and more frequent fungal infections. If confirmed by studies using refined exposure assessment methods accounting for bioaerosol dispersion, these results could have important implications for the living environment of pwCF.

Compounds in cigarette smoke induce EGR1 expression via the AHR, resulting in apoptosis and COPD.

Chronic obstructive pulmonary disease (COPD) is a major cause of mortality worldwide, and pulmonary epithelial cell apoptosis is regarded as one of the most important factors in its pathogenesis. Here, we examined the molecular mechanisms of apoptosis caused by cigarette smoke (CS). In the normal bronchial epithelium cell line BEAS-2B, a CS extract markedly induced apoptosis together with transient early growth response 1 (EGR1) protein expression, which is activated over time via the aryl hydrocarbon receptor (AHR). The CS extract-induced apoptosis decreased cell count of BEAS-2B cells and was significantly reversed by knockdown of either EGR1 or AHR. In vivo, the CS extract caused alveolar wall destruction, mimicking COPD, 1 week after intrathoracic injection. Bronchoalveolar lavage fluid (BALF) from the CS extract-treated mice contained massive numbers of apoptotic epithelial cells. Furthermore, it was found that aminoanthracene induced EGR1 expression and cell apoptosis. By contrast, the AHR antagonist stemregenin 1 (SR1) restored apoptosis upon CS treatment. These results suggest that aryl hydrocarbons, such as aminoanthracene, induce EGR1 expression via the AHR, resulting in cell apoptosis and that this can be prevented by administration of an antagonist of AHR.