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BackgroundAdmission eosinopenia (

OBJECTIVE: Progressive pulmonary fibrosis (PPF) is the leading cause of death in systemic sclerosis (SSc). This study aimed to develop a clinical prediction nomogram using clinical and biological data to assess risk of PPF among patients receiving treatment of SSc-related interstitial lung disease (SSc-ILD). METHODS: Patients with SSc-ILD who participated in the Scleroderma Lung Study II (SLS II) were randomized to treatment with either mycophenolate mofetil (MMF) or cyclophosphamide (CYC). Clinical and biological parameters were analyzed using univariable and multivariable logistic regression, and a nomogram was created to assess the risk of PPF and validated by bootstrap resampling. RESULTS: Among 112 participants with follow-up data, 22 (19.6%) met criteria for PPF between 12 and 24 months. An equal proportion of patients randomized to CYC (n = 11 of 56) and mycophenolate mofetil (n = 11 of 56) developed PPF. The baseline severity of ILD was similar for patients who did, compared to those who did not, experience PPF in terms of their baseline forced vital capacity percent predicted, diffusing capacity for carbon monoxide percent predicted, and quantitative radiological extent of ILD. Predictors in the nomogram included sex, baseline CXCL4 level, and baseline gastrointestinal reflux score. The nomogram demonstrated moderate discrimination in estimating the risk of PPF, with a C-index of 0.72 (95% confidence interval 0.60-0.84). CONCLUSION: The SLS II data set provided a unique opportunity to investigate predictors of PPF and develop a nomogram to help clinicians identify patients with SSc-ILD who require closer monitoring while on therapy and potentially an alternative treatment approach. This nomogram warrants external validation in other SSc-ILD cohorts to confirm its predictive power.

OBJECTIVE: To investigate whether symptoms of gastroesophageal reflux disease and radiographic measures of esophageal dilation are associated with radiographic progression of systemic sclerosis-related interstitial lung disease (SSc-ILD). METHODS: Participants of the Scleroderma Lung Study II, which compared mycophenolate versus cyclophosphamide for SSc-ILD, completed the reflux domain of the University of California Los Angeles Scleroderma Clinical Trials Consortium Gastrointestinal Tract 2.0 at baseline. The diameter and area of the esophagus in the region of maximum dilation was measured by quantitative image analysis. Univariate and multivariable linear regression analyses were created to evaluate the relationship between these measures of esophageal involvement and progression of SSc-ILD over 2 years, based on the radiologic quantitative interstitial lung disease (QILD) and quantitative lung fibrosis (QLF) in the lobe of maximum involvement (LM). All multivariable models controlled for the treatment arm, baseline ILD severity, and proton-pump inhibitor use. RESULTS: The baseline mean patient-reported reflux score was 0.57, indicating moderate reflux (n = 141). Baseline mean maximal esophageal diameter and area were 22 mm and 242 mm2 , respectively. Baseline reflux scores were significantly associated with the change in QLF-LM and QILD-LM in the univariate and multivariable models. Neither radiographic measure of esophageal dilation was associated with the change in radiographic measures of lung involvement. CONCLUSION: Severity of reflux symptoms as measured by an SSc-specific questionnaire was independently associated with the change in the radiographic extent of ILD and fibrosis over 2 years in patients with SSc-ILD. Two objective measures of esophageal dilation were not associated with radiographic progression of ILD, highlighting the need for improved objective measures of esophageal dysfunction in SSc.

BACKGROUND: Abnormal lung volumes representing air trapping identify the subset of smokers with preserved spirometry who develop spirometric chronic obstructive pulmonary disease (COPD) and adverse outcomes. However, how lung volumes evolve in early COPD as airflow obstruction develops remains unclear. METHODS: To establish how lung volumes change with the development of spirometric COPD, we examined lung volumes from the pulmonary function data (seated posture) available in the U.S. Department of Veterans Affairs electronic health records (n=71,356) and lung volumes measured by computed tomography (supine posture) available from the COPD Genetic Epidemiology (COPDGene®) study (n=7969) and the SubPopulations and InterMediate Outcome Measures In COPD Study (SPIROMICS) (n=2552) cohorts, and studied their cross-sectional distributions and longitudinal changes across the airflow obstruction spectrum. Patients with preserved ratio-impaired spirometry (PRISm) were excluded from this analysis. RESULTS: Lung volumes from all 3 cohorts showed similar patterns of distributions and longitudinal changes with worsening airflow obstruction. The distributions for total lung capacity (TLC), vital capacity (VC), and inspiratory capacity (IC) and their patterns of change were nonlinear and included different phases. When stratified by airflow obstruction using Global initiative for chronic Obstructive Lung Disease (GOLD) stages, patients with GOLD 1 (mild) COPD had larger lung volumes (TLC, VC, IC) compared to patients with GOLD 0 (smokers with preserved spirometry) or GOLD 2 (moderate) disease. In longitudinal follow-up of baseline GOLD 0 patients who progressed to spirometric COPD, those with an initially higher TLC and VC developed mild obstruction (GOLD 1) while those with an initially lower TLC and VC developed moderate obstruction (GOLD 2). CONCLUSIONS: In COPD, TLC, and VC have biphasic distributions, change in nonlinear fashions as obstruction worsens, and could differentiate those GOLD 0 patients at risk for more rapid spirometric disease progression.

BACKGROUND: Limited data are available regarding marijuana smokings impact on the development or progression of chronic obstructive pulmonary disease (COPD) in middle-aged or older adults with a variable history of tobacco cigarette smoking. METHODS: We divided ever-tobacco smoking participants in the SubPopulations and InteRmediate Outcomes In COPD Study (SPIROMICS) into 3 groups based on self-reported marijuana use: current, former, or never marijuana smokers (CMSs, FMSs or NMSs, respectively). Longitudinal data were analyzed in participants with ≥2 visits over a period of ≥52 weeks. MEASUREMENTS: We compared CMSs, FMSs, and NMSs, and those with varying amounts of lifetime marijuana use. Mixed effects linear regression models were used to analyze changes in spirometry, symptoms, health status, and radiographic metrics; zero-inflated negative binomial models were used for exacerbation rates. All models were adjusted for age, sex, race, baseline tobacco smoking amount, and forced expiratory volume in 1 second (FEV1) %predicted. RESULTS: Most participants were followed for ≥4 years. Annual rates of change in FEV1, incident COPD, respiratory symptoms, health status, radiographic extent of emphysema or air trapping, and total or severe exacerbations were not different between CMSs or FMSs versus NMSs or between those with any lifetime amount of marijuana use versus NMSs. CONCLUSIONS: Among SPIROMICS participants with or without COPD, neither former nor current marijuana smoking of any lifetime amount was associated with evidence of COPD progression or its development. Because of our studys limitations, these findings underscore the need for further studies to better understand longer-term effects of marijuana smoking in COPD.

Background: Illicit drug use has become a global epidemic, yet it is unclear if drug smoking increases the risk of tobacco-related cancers.Objectives: We aimed to evaluate hypothesized associations between smoking three drugs - opium, phencyclidine (PCP) and crack cocaine and lung and upper aerodigestive tract (UADT) cancers.Methods: A population-based case-control study with 611 lung cancer cases (50% male), 601 UADT cancers cases (76% male), and 1,040 controls (60% male) was conducted in Los Angeles County (1999-2004). Epidemiologic data including drug smoking histories were collected in face-to-face interviews. Associations were estimated with logistic regressions.Results: Adjusting for potential confounders, ever vs. never crack smoking was positively associated with UADT cancers (aOR = 1.56, 95% CI: 1.05, 2.33), and a dose-response relationship was observed for lifetime smoking frequency (p for trend = .024). Heavy (> median) vs. never crack smoking was associated with UADT cancers (aOR = 1.81, 95% CI: 1.07, 3.08) and lung cancer (aOR = 1.58, 95% CI: 0.88, 2.83). A positive association was also observed between heavy PCP smoking and UADT cancers (aOR = 2.29, 95% CI: 0.91, 5.79). Little or no associations were found between opium smoking and lung cancer or UADT cancers.Conclusion: The positive associations between illicit drug use and lung and/or UADT cancers suggest that smoking these drugs may increase the risk of tobacco-related cancers. Despite the low frequency of drug smoking and possible residual confounding, our findings may provide additional insights on the development of lung and UADT cancers.

OBJECTIVES: To establish a framework by which experts define disease subsets in systemic sclerosis associated interstitial lung disease (SSc-ILD). METHODS: A conceptual framework for subclinical, clinical and progressive ILD was provided to 83 experts, asking them to use the framework and classify actual SSc-ILD patients. Each patient profile was designed to be classified by at least four experts in terms of severity and risk of progression at baseline; progression was based on 1-year follow-up data. A consensus was reached if ≥75% of experts agreed. Experts provided information on which items were important in determining classification. RESULTS: Forty-four experts (53%) completed the survey. Consensus was achieved on the dimensions of severity (75%, 60 of 80 profiles), risk of progression (71%, 57 of 80 profiles) and progressive ILD (60%, 24 of 40 profiles). For profiles achieving consensus, most were classified as clinical ILD (92%), low risk (54%) and stable (71%). Severity and disease progression overlapped in terms of framework items that were most influential in classifying patients (forced vital capacity, extent of lung involvement on high resolution chest CT [HRCT]); risk of progression was influenced primarily by disease duration. CONCLUSIONS: Using our proposed conceptual framework, international experts were able to achieve a consensus on classifying SSc-ILD patients along the dimensions of disease severity, risk of progression and progression over time. Experts rely on similar items when classifying disease severity and progression: a combination of spirometry and gas exchange and quantitative HRCT.

BackgroundBronchodilator responsiveness (BDR) in obstructive lung disease varies over time and may be associated with distinct clinical features.Research questionIs consistent BDR over time (always present) differentially associated with obstructive lung disease features relative to inconsistent (sometimes present) or never (never present) BDR in tobacco-exposed people with or without COPD?Study design and methodsWe retrospectively analyzed data from 2,269 tobacco-exposed participants in the Subpopulations and Intermediate Outcome Measures in COPD Study with or without COPD. We used various BDR definitions: change of ≥ 200 mL and ≥ 12% in FEV1 (FEV1-BDR), change in FVC (FVC-BDR), and change in in FEV1, FVC or both (ATS-BDR). Using generalized linear models adjusted for demographics, smoking history, FEV1 % predicted after bronchodilator administration, and number of visits that the participant completed, we assessed the association of BDR group: (1) consistent BDR, (2) inconsistent BDR, and (3) never BDR with asthma, CT scan features, blood eosinophil levels, and FEV1 decline in participants without COPD (Global Initiative for Chronic Obstructive Lung Disease [GOLD] stage 0) and the entire cohort (participants with or without COPD).ResultsBoth consistent and inconsistent ATS-BDR were associated with asthma history and greater small airways disease (%parametric response mapping functional small airways disease) relative to never ATS-BDR in participants with GOLD stage 0 disease and the entire cohort. We observed similar findings using FEV1-BDR and FVC-BDR definitions. Eosinophils did not vary consistently among BDR groups. Consistent BDR was associated with FEV1 decline over time relative to never BDR in the entire cohort. In participants with GOLD stage 0 disease, both the inconsistent ATS-BDR group (OR, 3.20; 95% CI, 2.21-4.66; P < .001) and consistent ATS-BDR group (OR, 9.48; 95% CI, 3.77-29.12; P < .001) were associated with progression to COPD relative to the never ATS-BDR group.InterpretationDemonstration of BDR, even once, describes an obstructive lung disease phenotype with a history of asthma and greater small airways disease. Consistent demonstration of BDR indicated a high risk of lung function decline over time in the entire cohort and was associated with higher risk of progression to COPD in patients with GOLD stage 0 disease.

OBJECTIVE: To assess the predictive significance of blood neutrophil count and the ratio between neutrophil and lymphocyte count (neutrophil-to-lymphocyte ratio [NLR]) for disease severity and mortality in systemic sclerosis (SSc). METHODS: Neutrophil and lymphocyte counts were prospectively measured in the Genetics versus Environment in Scleroderma Outcome Study (GENISOS) and the Scleroderma Lung Study II (SLS II). Forced vital capacity percent predicted (FVC%) and modified Rodnan skin thickness score (MRSS) were used as surrogate measures for disease severity. Longitudinal analyses were performed using generalized linear mixed models. Cox proportional hazards models evaluated the predictive significance of these cell counts for mortality. RESULTS: Of the 447 SSc patients in the GENISOS cohort at the time of analysis, 377 (84.3%) had available baseline blood neutrophil and lymphocyte counts. Higher baseline neutrophil count and NLR predicted lower serially obtained FVC% (b = -4.74, P = 0.009 and b = -2.68, P = 0.028, respectively) and higher serially obtained MRSS (b = 4.07, P

BACKGROUND: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) considers blood eosinophil counts < 100 cells/μL (BEC≤100) in people with COPD to predict poor inhaled corticosteroid (ICS) responsiveness. However, the BEC≤100 phenotype is inadequately characterized, especially in advanced COPD. RESEARCH QUESTION: Are there differences between GOLD group D patients with high BEC and those with low BEC regarding baseline characteristics and longitudinal outcomes? STUDY DESIGN AND METHODS: We used multivariable mixed models and logistic regression to contrast clinical characteristics and outcomes of BEC≤100 vs BEC > 100 (BEC100+) in all subjects with COPD (n = 1,414) and GOLD group D subjects (n = 185) not receiving ICS. RESULTS: We identified n = 485 with BEC≤100 (n = 61 GOLD group D) and n = 929 people with BEC100+ (n = 124 GOLD group D). BEC≤100 status was stable at 6 weeks and approximately 52 weeks (intraclass correlations of 0.78 and 0.71, respectively). Compared with BEC100+, BEC≤100 comprised more women, with greater current smoking, and less frequent childhood asthma. Among all analyzed participants, the two BEC-defined subsets showed similar rates of lung function decline (mean slope, BEC≤100 vs BEC100+, -50 vs -39 mL/y; P = .140), exacerbations (0.40 vs 0.36/y; P = .098), subsequent ICS initiation (2.5% vs 4.4%; P = .071), and mortality (7.8% vs 8.4%; P = .715). However, in GOLD group D, people with BEC≤100 showed higher exacerbation rates within 365 days of enrollment (0.62 vs 0.33/y; P = .002) and total follow-up (1.16 vs 0.83/y; P = .014). They also had greater lung function decline (mean slope of -68 mL/y vs -23 mL/y; P = .036) and had greater emphysema at baseline (voxels < 950 Hounsfield units at total lung capacity of 7.46% vs 4.61%; P = .029). INTERPRETATION: In non-ICS-treated GOLD group D COPD, people with BEC≤100 had more baseline emphysema, prospective exacerbations, and lung function decline. Our analysis has identified a particularly vulnerable subpopulation of people with COPD, suggesting the need for studies focused specifically on their therapeutic treatment. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT01969344; URL: www. CLINICALTRIALS: gov.

INTRODUCTION: Clinical decisions in chronic obstructive pulmonary disease (COPD) treatment often utilize serially assessed physiologic parameters and biomarkers. To better understand the reliability of these tests, we evaluated changes in commonly assessed biomarkers over 3 months in patients with clinically stable COPD. METHODS: We performed an observational prospective cohort study of 89 individuals with clinically stable COPD, defined as no exacerbation history within 3 months of enrollment. Biomarkers included lung function and functional performance status, patient-reported outcomes of symptoms and health status, and blood markers of inflammation. The correlation between testing at baseline and at 3-month follow-up was reported as the intraclass correlation coefficient (ICC). Outliers had significant variability between tests, defined as >1.645 standard deviations between the two measurements. Differences in clinical features between outliers and others were compared. RESULTS: Participants with COPD (n = 89) were 70.5 ± 6.7 years old, 54 (61%) male, had a 40 pack-year smoking history with 24.7% being current smokers, and postbronchodilator forced expiratory volume in one second (FEV1) 62.3 ± 22.7% predicted. The biomarkers with excellent agreement between the initial and the follow-up measurements were FEV1 (ICC = 0.96), Saint Georges Respiratory Questionnaire (SGRQ) (ICC = 0.98), COPD Assessment Test (CAT) (ICC = 0.93) and C-reactive protein (CRP) (ICC = 0.90). By contrast, parameters showing less robust agreement were 6-minute walking distance (ICC = 0.75), eosinophil count (ICC = 0.77), erythrocyte sedimentation rate (ICC = 0.75) and white blood cell count (ICC = 0.48). Individuals with greater variability in biomarkers reported chronic bronchitis more often and had higher baseline SGRQ and CAT scores. CONCLUSION: Our study evaluated the stability of commonly assessed biomarkers in clinically stable COPD and showed excellent agreement between baseline and three-month follow-up values for FEV1, SGRQ, CAT and CRP. Individuals with chronic bronchitis and more symptomatic disease at baseline demonstrated greater variability in 3-month interval biomarkers.

BACKGROUND: Observational studies have shown that men with systemic sclerosis have an increased risk of interstitial lung disease (ILD) and mortality compared with women. However, previous studies have not controlled for treatment effect or evaluated the biological mechanism or mechanisms underlying this sex difference. We aimed to compare ILD progression and long-term morbidity and mortality outcomes in male and female participants of two randomised controlled trials for systemic sclerosis-associated ILD. METHODS: For this post-hoc analysis, data from all participants in the Scleroderma Lung Study (SLS) I and SLS II were analysed. The primary objective was to explore the effect of sex on the course of the percentage predicted forced vital capacity (FVC) during and after active treatment over the 24-month study periods. In SLS I, 158 participants (111 women, 47 men) were randomly assigned to receive oral cyclophosphamide (cyclophosphamide; ≤2 mg/kg daily) or placebo; in SLS II, 142 participants (105 women, 37 men) were randomly assigned to receive oral mycophenolate mofetil (1500 mg twice daily) or oral cyclophosphamide (≤2 mg/kg daily). Sex (ie, male or female) was self-reported in both studies by the participants. Changes in radiographic fibrosis and time to death and respiratory failure were secondary outcomes of the present analysis. Baseline levels of biomarkers implicated in the pathobiology of systemic sclerosis-associated ILD were measured in bronchoalveolar lavage fluid in SLS I. FINDINGS: In the SLS I placebo group, the rate of decline in percentage predicted FVC from 3 months to 12 months was greater in men than in women, but the difference was not significant (estimated effect -0·29 [95% CI -0·67 to 0·10]; p=0·14). In SLS II, the rate of decline in percentage predicted FVC from 3 months to 12 months was significantly worse in men treated with either cyclophosphamide (estimated effect -0·72; [95% CI -1·14 to -0·31]; p=0·00060) or mycophenolate mofetil (estimated effect -0·34 [-0·58 to -0·10]; p=0·0051) than in women. A greater proportion of men had a decline in percentage predicted FVC of 10% or greater compared with women for the pooled active treatment groups from SLS I and SLS II and the placebo group of SLS I. Men had worse radiographic outcomes at 2 years than women in SLS II, even after adjusting for baseline disease severity and treatment arm assignment. Long-term survival was worse in men in SLS I (log-rank test p=0·080) and SLS II (log-rank test p=0·030). In SLS II, male sex was independently associated with increased mortality (hazard ratio 2·42 [95% CI 1·16 to 5·04]; p=0·018). In bronchoalveolar lavage fluid, men had increased concentrations of pro-fibrotic mediators (eg, matrix metalloproteinase-13 and tissue inhibitor of metallopeptidase 1), whereas women had increased pro-inflammatory mediators (eg, interleukin [IL]-12, IL-7, and granulocyte-colony stimulating factor). INTERPRETATION: In two randomised controlled trials, men with systemic sclerosis-associated ILD had a less favourable course of ILD both with and without active treatment, as well as worse long-term survival. Sex differences in pro-fibrotic or inflammatory mediators of disease might account for these differences and warrant future study. FUNDING: US National Institutes of Health; US National Heart, Lung, and Blood Institute; US National Institute of Arthritis and Musculoskeletal and Skin Diseases; Bristol Myers Squibb; and Hoffmann-LaRoche.

Rationale: Chronic obstructive pulmonary disease (COPD) is defined by fixed spirometric ratio, FEV1/FVC

OBJECTIVE: To explore the presence of small airway disease (SAD) and emphysema in scleroderma-related interstitial lung disease (SSc-ILD) and to evaluate the physiologic and clinical correlates of SAD in SSc-ILD. METHODS: Thoracic high-resolution computed tomography (HRCT) images obtained from the Scleroderma Lung Study II (SLSII) participants were reviewed by a group of thoracic radiologists. The presence of SAD was assessed by visual assessment for air trapping. HRCT scans were also evaluated for the presence of emphysema. The association of the presence of air trapping and emphysema with physiological measures of airway disease and clinical variables was evaluated. RESULTS: A total of 155 baseline HRCT scans were reviewed. For assessment of air trapping, images needed to be adequate end-expiratory examinations, leaving 123 scans. Air trapping was seen in 13/123 (10.6%) of the SSc-ILD cohort and was independent of smoking history, asthma or the presence of gastroesophageal reflux. Air trapping on HRCT was not associated with physiologic evidence of SAD. We also identified 8/155 (5.2%) patients with emphysema on HRCT, which was independent of SAD and found mostly in prior smokers. CONCLUSION: We report the first study of air trapping on standardized, high-quality HRCT images as a reflection of SAD in a relatively large, well characterized SSc-ILD cohort. The presence of SAD in non-smoking SSc-ILD patients supports that SSc may cause not only restrictive lung disease (SSc-ILD), but also, to a lesser extent, obstructive disease. Physiologic measures alone may be inadequate to detect airway disease in patients with SSc-ILD.

ObjectivesTo characterise the peripheral blood cell (PBC) gene expression changes ensuing from mycophenolate mofetil (MMF) or cyclophosphamide (CYC) treatment and to determine the predictive significance of baseline PBC transcript scores for response to immunosuppression in systemic sclerosis (SSc)-related interstitial lung disease (ILD).MethodsPBC RNA samples from baseline and 12-month visits, corresponding to the active treatment period of both arms in Scleroderma Lung Study II, were investigated by global RNA sequencing. Joint models were created to examine the predictive significance of baseline composite modular scores for the course of forced vital capacity (FVC) per cent predicted measurements from 3 to 12 months.Results134 patients with SSc-ILD (CYC=69 and MMF=65) were investigated. CYC led to an upregulation of erythropoiesis, inflammation and myeloid lineage-related modules and a downregulation of lymphoid lineage-related modules. The modular changes resulting from MMF treatment were more modest and included a downregulation of plasmablast module. In the longitudinal analysis, none of the baseline transcript module scores showed predictive significance for FVC% course in the CYC arm. In contrast, in the MMF arm, higher baseline lymphoid lineage modules predicted better subsequent FVC% course, while higher baseline myeloid lineage and inflammation modules predicted worse subsequent FVC% course.ConclusionConsistent with the primary mechanism of action of MMF on lymphocytes, patients with SSc-ILD with higher baseline lymphoid module scores had better FVC% course, while those with higher myeloid cell lineage activation score had poorer FVC% course on MMF.

BackgroundImproved understanding of the pathways associated with airway pathophysiologic features in COPD will identify new predictive biomarkers and novel therapeutic targets.Research questionWhich physiologic pathways are altered in the airways of patients with COPD and will predict exacerbations?Study design and methodsWe applied a mass spectrometric panel of metabolomic biomarkers related to mucus hydration and inflammation to sputa from the multicenter Subpopulations and Intermediate Outcome Measures in COPD Study. Biomarkers elevated in sputa from patients with COPD were evaluated for relationships to measures of COPD disease severity and their ability to predict future exacerbations.ResultsSputum supernatants from 980 patients were analyzed: 77 healthy nonsmokers, 341 smokers with preserved spirometry, and 562 patients with COPD (178 with Global Initiative on Chronic Obstructive Lung Disease [GOLD] stage 1 disease, 303 with GOLD stage 2 disease, and 81 with GOLD stage 3 disease) were analyzed. Biomarkers from multiple pathways were elevated in COPD and correlated with sputum neutrophil counts. Among the most significant analytes (false discovery rate, 0.1) were sialic acid, hypoxanthine, xanthine, methylthioadenosine, adenine, and glutathione. Sialic acid and hypoxanthine were associated strongly with measures of disease severity, and elevation of these biomarkers was associated with shorter time to exacerbation and improved prediction models of future exacerbations.InterpretationBiomarker evaluation implicated pathways involved in mucus hydration, adenosine metabolism, methionine salvage, and oxidative stress in COPD airway pathophysiologic characteristics. Therapies that target these pathways may be of benefit in COPD, and a simple model adding sputum-soluble phase biomarkers improves prediction of pulmonary exacerbations.Trial registryClinicalTrials.gov; No.: NCT01969344; URL: www.Clinicaltrialsgov.

BackgroundRadiographic end points commonly are included in therapeutic trials for systemic sclerosis (SSc)-interstitial lung disease (ILD); however, the relationship between these outcomes and long-term mortality is unclear.Research questionDo short-term changes in radiographic measures of ILD predict long-term survival in patients with SSc?Study design and methodsThe Scleroderma Lung Study (SLS) I and II evaluated the safety and efficacy of cyclophosphamide (in SLS I and II) and mycophenolate mofetil (in SLS II) for the treatment of SSc-ILD. Changes in the extent of ILD over time were assessed on high-resolution CT scans of the chest by quantitative image analysis, an approach that applies a computer-based algorithm to assess changes in the radiographic extent of ILD objectively. Participants subsequently were followed for up to 12 years (SLS I) and 8 years (SLS II). Cox proportional hazards models determined whether the change in the quantitative radiographic extent of ILD predicted survival, adjusting for other known predictors of survival.ResultsAmong SLS I and II participants, 82 and 90 had follow-up imaging scans, respectively, and were included in the analysis. Participants in both trials who showed an increase in the total quantitative radiographic extent of ILD scores of ≥ 2% at 12 months (SLS I) or 24 months (SLS II) experienced significantly worse long-term survival than those with change scores of

BackgroundForced expiratory volume in 1 second (FEV1) is central to the diagnosis of chronic obstructive pulmonary disease (COPD) but is imprecise in classifying disease burden. We examined the potential of the maximal mid-expiratory flow rate (forced expiratory flow rate between 25% and 75% [FEF25%-75%]) as an additional tool for characterizing pathophysiology in COPD.ObjectiveTo determine whether FEF25%-75% helps predict clinical and radiographic abnormalities in COPD.Study design and methodsThe SubPopulations and InteRediate Outcome Measures In COPD Study (SPIROMICS) enrolled a prospective cohort of 2978 nonsmokers and ever-smokers, with and without COPD, to identify phenotypes and intermediate markers of disease progression. We used baseline data from 2771 ever-smokers from the SPIROMICS cohort to identify associations between percent predicted FEF25%-75% (%predFEF25%-75%) and both clinical markers and computed tomography (CT) findings of smoking-related lung disease.ResultsLower %predFEF25-75% was associated with more severe disease, manifested radiographically by increased functional small airways disease, emphysema (most notably with homogeneous distribution), CT-measured residual volume, total lung capacity (TLC), and airway wall thickness, and clinically by increased symptoms, decreased 6-minute walk distance, and increased bronchodilator responsiveness (BDR). A lower %predFEF25-75% remained significantly associated with increased emphysema, functional small airways disease, TLC, and BDR after adjustment for FEV1 or forced vital capacity (FVC).InterpretationThe %predFEF25-75% provides additional information about disease manifestation beyond FEV1. These associations may reflect loss of elastic recoil and air trapping from emphysema and intrinsic small airways disease. Thus, %predFEF25-75% helps link the anatomic pathology and deranged physiology of COPD.

BackgroundSmall airways are known to be affected early in the course of COPD; however, traditional spirometric indices may not accurately identify small airways disease.Research questionCan forced expiratory volume in 3 s/forced expiratory volume in 6 s (FEV3/FEV6) identify early airflow abnormalities and predict future clinically important respiratory-related outcomes, including development of COPD?Study design and methodsThe study included 832 current and former smokers with post-bronchodilator FEV1/FVC ≥ 0.7 from the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort. Participants were classified as having a reduced pre-bronchodilator FEV3/FEV6 based on lower limit of normal (LLN) values. Repeatability analysis was performed for FEV3 and FEV6. Regression modeling was used to evaluate the relationship between baseline FEV3/FEV6 and outcome measures, including functional small airways disease, on thoracic imaging and respiratory exacerbations. Interval-censored analysis was used to assess progression to COPD.ResultsFEV3/FEV6 less than the LLN at baseline, defined as reduced compared with FEV3/FEV6 at or above the LLN, was associated with lower FEV1, poorer health status (St. George's Respiratory Questionnaire score), more emphysema, and more functional small airways disease on quantitative imaging. FEV3 and FEV6 showed excellent agreement between repeat measurements. A reduced FEV3/FEV6 was associated with increased odds of a severe respiratory exacerbation within the first year of follow-up and decreased time to first exacerbation. A low FEV3/FEV6 was also associated with development of COPD according to spirometry results (post-bronchodilator FEV1/FVC < 0.7) during study follow-up.InterpretationFEV3/FEV6 is a routinely available and repeatable spirometric index that can be useful in the evaluation of early airflow obstruction in current and former smokers without COPD. A reduced FEV3/FEV6 can identify those at risk for future development of COPD and respiratory exacerbations.Clinical trial registrationClinicalTrials.gov; No.: NCT01969344; URL: www.Clinicaltrialsgov: ClinicalTrials.gov.

The purpose of this study was to explore the relationships between heart rate variability (HRV) and various phenotypic measures that relate to health and functional status in chronic obstructive pulmonary disease (COPD), and secondly, to demonstrate the feasibility of ascertaining HRV via a chest-worn wearable biosensor in COPD patients. HRV analysis was performed using SDNN (standard deviation of the mean of all normal R-R intervals), low frequency (LF), high frequency (HF), and LF/HF ratio. We evaluated the associations between HRV and COPD severity, class of bronchodilator therapy prescribed, and patient reported outcomes. Seventy-nine participants with COPD were enrolled. There were no differences in SDNN, HF, and LF/HF ratio according to COPD severity. The SDNN in participants treated with concurrent beta-agonists and muscarinic antagonists was lower than that in other participants after adjusting heart rate (beta coefficient -3.980, p = 0.019). The SDNN was positively correlated with Veterans Specific Activity Questionnaire (VSAQ) score (r = 0.308, p = 0.006) and handgrip strength (r = 0.285, p = 0.011), and negatively correlated with dyspnea by modified Medical Research Council (mMRC) questionnaire (r = -0.234, p = 0.039), health status by Saint Georges Respiratory Questionnaire (SGRQ) (r = -0.298, p = 0.008), symptoms by COPD Assessment Test (CAT) (r = -0.280, p = 0.012), and BODE index (r = -0.269, p = 0.020). When measured by a chest-worn wearable device, reduced HRV was observed in COPD participants receiving inhaled beta-sympathomimetic agonist and muscarinic antagonists. HRV was also correlated with various health status and performance measures.

Rationale: Individuals with chronic obstructive pulmonary disease (COPD) have a high prevalence of depression, which is associated with increased COPD hospitalizations and readmissions. Objectives: Examine the impact of depressive symptoms compared with FEV1% on COPD morbidity. Methods: Using longitudinal data from individuals with COPD in the Subpopulations and Intermediate Outcome Measures in COPD Study, longitudinal growth analysis was performed to assess COPD morbidity by assessing differences in baseline 6-minute walk distance and patient reported outcomes (PROs) and their rate of change over time explained by depressive symptoms or lung function, as measured by Hospital Anxiety and Depression Scale or FEV1% respectively. PROs consisted of in-person completion of St. George's Respiratory Questionnaire, COPD Assessment Test, Functional Assessment of Chronic Illness Therapy Fatigue, and Modified Medical Research Council Dyspnea Scale measures. Results: Of the individuals analyzed (n = 1,830), 43% were female, 81% Caucasian with mean ± SD age of 65.1 ± 8.1, and 52.7 ± 27.5 pack-years smoking. Mean ± SD FEV1% was 60.9 ± 23.0% and 20% had clinically significant depressive symptoms. Adjusted models showed higher Hospital Anxiety and Depression Scale scores and lower FEV1% each were associated with worse PROs at baseline (P ⩽ 0.001). Depression accounted for more baseline variance in St. George's Respiratory Questionnaire, COPD Assessment Test, and Functional Assessment of Chronic Illness Therapy Fatigue than FEV1%, explaining 30-67% of heterogeneity. FEV1% accounted for more baseline variance in Modified Medical Research Council Dyspnea Scale and 6-minute walk distance than depression, explaining 16-32% of heterogeneity. Depressive symptoms accounted for 3-17% variance in change over time in PROs. In contrast, FEV1% accounted for 1-4% variance over time in PROs. Conclusions: Depression is more strongly associated with many PROs at baseline and their change over time compared with FEV1%. Recognizing and incorporating the impact of depressive symptoms into individualized care may improve COPD outcomes.

BackgroundChronic obstructive pulmonary disease (COPD) is associated with worsened outcomes in COVID-19 (coronavirus disease 2019). However, data remain fraught with heterogeneity and bias from comorbid conditions. Additionally, data on the impact of COPD-specific factors, such as pre-hospital medications and pulmonologist involvement, remain sparse.ObjectiveWe report a single-center analysis of COPD patients hospitalized with COVID-19 compared to those without COPD. Primary outcomes include ICU admission, mechanical ventilation, and in-hospital mortality.MethodsWe evaluated all patients ≥40 years admitted with PCR-confirmed COVID-19 between February 2020 and February 2021. COPD was defined by documented ICD-10 diagnosis of COPD, confirmed smoking history, and active bronchodilator use. We compared outcomes between COPD patients and the remainder of the COVID-19 cohort. Multivariable analyses were adjusted for age, sex, smoking status, and comorbid conditions.ResultsOf 1537 hospitalized COVID-19 patients, 122 (7.9%) carried a diagnosis of COPD. The COPD cohort was older (74 ± 13 vs 66 ± 15 years, P < 0.001) and more often former smokers (P < 0.001). Comorbid conditions including diabetes, cardiovascular disease, and kidney disease were more prevalent in the COPD group (P < 0.001). After adjusting for comorbid conditions, the COPD cohort had higher severity scores and trended towards fewer hospital-free days. Among patients with COPD, pre-hospital use of aspirin was associated with decreased ICU admissions (aHR 0.56, P = 0.049) and mechanical ventilation (aHR 0.25, P = 0.008), while LAMAs (long-acting muscarinic antagonists) were associated with decreased in-hospital mortality (aHR 0.34, P = 0.047). Involvement of pulmonology in pre-hospital management of COPD was not found to significantly affect outcomes.ConclusionWhen corrected for comorbid illnesses, COPD was associated with more severe disease but not with increased ICU admission, mechanical ventilation, or in-hospital mortality rates. Among COPD patients, prehospital treatment with aspirin and COPD-directed therapies were associated with improved outcomes.

BackgroundTraditional hookah smoking has grown quickly to become a global tobacco epidemic. More recently, electronic hookahs (e-hookahs)-vaped through traditional water pipes-were introduced as healthier alternatives to combustible hookah. With combustible tobacco smoking, oxidative stress, inflammation, and vascular stiffness are key components in the development and progression of atherosclerosis. The comparable effects of hookah are unknown.Research questionWhat is the differential acute effect of e-hookah vaping vs combustible hookah smoking on oxidation, inflammation, and arterial stiffness?Study design and methodsIn a randomized crossover design study, among a cohort of 17 healthy young adult chronic hookah smokers, we investigated the effect of e-hookah vaping and hookah smoking on measures of conduit arterial stiffness, including carotid-femoral pulse wave velocity (PWV), augmentation index-corrected for heart rate before and after a 30-min exposure session. We assessed a panel of circulating biomarkers indicative of inflammation and oxidants and measured plasma nicotine and exhaled carbon monoxide (CO) levels before and after the sessions.Resultse-Hookah vaping tended to lead to a larger acute increase in PWV than hookah smoking (mean ± SE: e-hookah, +0.74 ± 0.12 m/s; combustible hookah, +0.57 ± 0.14 m/s [P < .05 for both]), indicative of large artery stiffening. Compared with baseline, only e-hookah vaping induced an acute increase in augmentation index (e-hookah, +5.58 ± 1.54% [P = .004]; combustible hookah, +2.87 ± 2.12% [P = not significant]). These vascular changes were accompanied by elevation of the proinflammatory biomarkers high-sensitivity C-reactive protein, fibrinogen, and tumor necrosis factor α after vaping (all P < .05). No changes in biomarkers of inflammation and oxidants were observed after smoking. Compared with baseline, exhaled CO levels were higher after smoking than after vaping (+36.81 ± 6.70 parts per million vs -0.38 ± 0.22 parts per million; P < .001), whereas plasma nicotine concentrations were comparable (+6.14 ± 1.03 ng/mL vs +5.24 ± 0.96 ng/mL; P = .478).InterpretationAlthough advertised to be "safe," flavored e-hookah vaping exerts injurious effects on the vasculature that are, at least in part, mediated by inflammation.Trial registryClinicalTrials.gov; No.: NCT03690427; URL: www.clinicaltrials.gov.

BackgroundWhile cannabis is known to have immunomodulatory properties, the clinical consequences of its use on outcomes in COVID-19 have not been extensively evaluated. We aimed to assess whether cannabis users hospitalized for COVID-19 had improved outcomes compared to non-users.MethodsWe conducted a retrospective analysis of 1831 patients admitted to two medical centers in Southern California with a diagnosis of COVID-19. We evaluated outcomes including NIH COVID-19 Severity Score, need for supplemental oxygen, ICU (intensive care unit) admission, mechanical ventilation, length of hospitalization, and in-hospital death for cannabis users and non-users. Cannabis use was reported in the patient's social history. Propensity matching was used to account for differences in age, body-mass index, sex, race, tobacco smoking history, and comorbidities known to be risk factors for COVID-19 mortality between cannabis users and non-users.ResultsOf 1831 patients admitted with COVID-19, 69 patients reported active cannabis use (4% of the cohort). Active users were younger (44 years vs. 62 years, p < 0.001), less often diabetic (23.2% vs 37.2%, p < 0.021), and more frequently active tobacco smokers (20.3% vs. 4.1%, p < 0.001) compared to non-users. Notably, active users had lower levels of inflammatory markers upon admission than non-users-CRP (C-reactive protein) (3.7 mg/L vs 7.6 mg/L, p < 0.001), ferritin (282 μg/L vs 622 μg/L, p < 0.001), D-dimer (468 ng/mL vs 1140 ng/mL, p = 0.017), and procalcitonin (0.10 ng/mL vs 0.15 ng/mL, p = 0.001). Based on univariate analysis, cannabis users had significantly better outcomes compared to non-users as reflected in lower NIH scores (5.1 vs 6.0, p < 0.001), shorter hospitalization (4 days vs 6 days, p < 0.001), lower ICU admission rates (12% vs 31%, p < 0.001), and less need for mechanical ventilation (6% vs 17%, p = 0.027). Using propensity matching, differences in overall survival were not statistically significant between cannabis users and non-users, nevertheless ICU admission was 12 percentage points lower (p = 0.018) and intubation rates were 6 percentage points lower (p = 0.017) in cannabis users.ConclusionsThis retrospective cohort study suggests that active cannabis users hospitalized with COVID-19 had better clinical outcomes compared with non-users, including decreased need for ICU admission or mechanical ventilation. However, our results need to be interpreted with caution given the limitations of a retrospective analysis. Prospective and observational studies will better elucidate the effects cannabis use in COVID-19 patients.

BackgroundWe previously reported a Phase 1/2 randomized placebo-controlled trial of systemic administration of bone marrow-derived allogeneic MSCs (remestemcel-L) in COPD. While safety profile was good, no functional efficacy was observed. However, in view of growing recognition of effects of inflammatory environments on MSC actions we conducted a post-hoc analysis with stratification by baseline levels of a circulating inflammatory marker, C-reactive protein (CRP) to determine the effects of MSC administration in COPD patients with varying circulating CRP levels.MethodsTime course of lung function, exercise performance, patient reported responses, and exacerbation frequency following four monthly infusions of remestemcel-L vs. placebo were re-assessed in subgroups based on baseline circulating CRP levels.ResultsIn COPD patients with baseline CRP ≥ 4 mg/L, compared to COPD patients receiving placebo (N = 17), those treated with remestemcel-L (N = 12), demonstrated significant improvements from baseline in forced expiratory volume in one second, forced vital capacity, and six minute walk distance at 120 days with treatment differences evident as early as 10 days after the first infusion. Significant although smaller benefits were also detected in those with CRP levels ≥ 2 or ≥ 3 mg/L. These improvements persisted variably over the 2-year observational period. No significant benefits were observed in patient reported responses or number of COPD exacerbations between treatment groups.ConclusionIn an inflammatory environment, defined by elevated circulating CRP, remestemcel-L administration yielded at least transient meaningful pulmonary and functional improvements. These findings warrant further investigation of potential MSC-based therapies in COPD and other inflammatory pulmonary diseases.Trial registrationClinicaltrials.gov NCT00683722.

Inhaled bronchodilators are central for the treatment of chronic obstructive pulmonary disease (COPD), as they can provide symptom relief and reduce the frequency and severity of exacerbations while improving health status and exercise tolerance. In 2017, glycopyrrolate (GLY) delivered via the eFlow® closed system (CS) nebulizer (nebulized GLY; 25 µg twice daily), was approved by the US Food and Drug Administration for maintenance treatment of moderate-to-very-severe COPD. This approval was based largely on results from the replicate, placebo-controlled, Phase III clinical trials- GOLDEN 3 and 4. In this review, we summarize key findings from secondary analyses of the GOLDEN 3 and 4 studies, and provide a comprehensive overview that may assist both pulmonologists and primary-care providers in their treatment decisions. Comorbidities are common among patients with COPD in clinical practice and may impact bronchodilator efficacy. This review highlights outcomes among subpopulations of patients with comorbidities (e.g., anxiety/depression, cardiovascular disease), and their impact on the efficacy of nebulized GLY. In addition, the efficacy and safety of nebulized GLY across various demographics (e.g., age, gender) and baseline disease characteristics (e.g., disease severity, rescue medication use) are discussed. Real-world outcomes with nebulized GLY, including device satisfaction, healthcare resource utilization, and exacerbations, are also presented. These secondary analyses and real-world data complement the primary results with nebulized GLY from Phase III studies and support the need for the inclusion of patients representative of real-world clinical practice in RCTs. In addition, these data suggest that RCTs for COPD therapies should be complemented with real-world observational studies.

BackgroundMild expiratory flow limitation may not be recognized using traditional spirometric criteria based on the ratio of FEV1/FVC.Research questionDoes slow vital capacity (SVC) instead of FVC increase the sensitivity of spirometry to identify patients with early or mild obstructive lung disease?Study design and methodsWe included 854 current and former smokers from the Subpopulations and Intermediate Outcome Measures in COPD Study cohort with a postbronchodilator FEV1/FVC ≥ 0.7 and FEV1 % predicted of ≥ 80% at enrollment. We compared baseline characteristics, chest CT scan features, exacerbations, and progression to COPD (postbronchodilator FEV1/FVC, < 0.7) during the follow-up period between 734 participants with postbronchodilator FEV1/SVC of ≥ 0.7 and 120 with postbronchodilator FEV1/SVC < 0.7 at the enrollment. We performed multivariate linear and logistic regression models and negative binomial and interval-censored proportion hazards regression models adjusted for demographics and smoking exposure to examine the association of FEV1/SVC < 0.7 with those characteristics and outcomes.ResultsParticipants with FEV1/SVC < 0.7 were older and had lower FEV1 and more emphysema than those with FEV1/SVC ≥ 0.7. In adjusted analysis, individuals with postbronchodilator FEV1/SVC < 0.7 showed a greater percentage of emphysema by 0.45% (95% CI, 0.09%-0.82%), percentage of gas trapping by 2.52% (95% CI, 0.59%-4.44%), and percentage of functional small airways disease based on parametric response mapping by 2.78% (95% CI, 0.72%-4.83%) at baseline than those with FEV1/SVC ≥ 0.7. During a median follow-up time of 1,500 days, an FEV1/SVC < 0.7 was not associated with total exacerbations (incident rate ratio [IRR], 1.61; 95% CI, 0.97-2.64), but was associated with severe exacerbations (IRR, 2.60; 95% CI, 1.04-4.89). An FEV1/SVC < 0.7 was associated with progression to COPD during a 3-year follow-up even after adjustment for demographics and smoking exposure (hazard ratio, 3.93; 95% CI, 2.71-5.72). We found similar results when we examined the association of prebronchodilator FEV1/SVC < 0.7 or FEV1/SVC less than the lower limit of normal with chest CT scan features and progression to COPD.InterpretationLow FEV1 to SVC in current and former smokers with normal spirometry results can identify individuals with CT scan features of COPD who are at risk for severe exacerbations and is associated with progression to COPD in the future.Trial registryClinicalTrials.gov; No.: NCT01969344T4; URL: www.clinicaltrials.gov.

OBJECTIVE: Response to immunosuppression is highly variable in systemic sclerosis (SSc)-related interstitial lung disease (ILD). This study was undertaken to determine whether a composite serum interferon (IFN)-inducible protein score exhibits predictive significance for the response to immunosuppression in SSc-ILD. METHODS: Serum samples collected in the Scleroderma Lung Study II, a randomized controlled trial of mycophenolate mofetil (MMF) versus cyclophosphamide (CYC), were examined. Results were validated in an independent observational cohort receiving active treatment. A composite score of 6 IFN-inducible proteins IFNγ-inducible 10-kd protein, monokine induced by IFNγ, monocyte chemotactic protein 2, β2 -microglobulin, tumor necrosis factor receptor type II, and macrophage inflammatory protein 3β) was calculated, and its predictive significance for longitudinal forced vital capacity percent predicted measurements was evaluated. RESULTS: Higher baseline IFN-inducible protein score predicted better response over 3 to 12 months in the MMF arm (point estimate = 0.41, P = 0.001) and CYC arm (point estimate = 0.91, P = 0.009). In contrast, higher baseline C-reactive protein (CRP) levels were predictive of a worse ILD course in both treatment arms. The predictive significance of the IFN-inducible protein score and CRP levels remained after adjustment for baseline demographic and clinical predictors. During the second year of treatment, in which patients in the CYC arm were switched to placebo, a higher IFN-inducible protein score at 12 months showed a trend toward predicting a worse ILD course (point estimate = -0.61, P = 0.068), while it remained predictive of better response to active immunosuppression in the MMF arm (point estimate = 0.28, P = 0.029). The predictive significance of baseline IFN-inducible protein score was replicated in the independent cohort (rs = 0.43, P = 0.028). CONCLUSION: A higher IFN-inducible protein score in SSc-ILD is predictive of better response to immunosuppression and could potentially be used to identify patients who may derive the most benefit from MMF or CYC.

BackgroundWe previously reported a Phase 1/2 randomized placebo-controlled trial of systemic administration of bone marrow-derived allogeneic MSCs (remestemcel-L) in COPD. While safety profile was good, no functional efficacy was observed. However, in view of growing recognition of effects of inflammatory environments on MSC actions we conducted a post-hoc analysis with stratification by baseline levels of a circulating inflammatory marker, C-reactive protein (CRP) to determine the effects of MSC administration in COPD patients with varying circulating CRP levels.MethodsTime course of lung function, exercise performance, patient reported responses, and exacerbation frequency following four monthly infusions of remestemcel-L vs. placebo were re-assessed in subgroups based on baseline circulating CRP levels.ResultsIn COPD patients with baseline CRP ≥ 4 mg/L, compared to COPD patients receiving placebo (N = 17), those treated with remestemcel-L (N = 12), demonstrated significant improvements from baseline in forced expiratory volume in one second, forced vital capacity, and six minute walk distance at 120 days with treatment differences evident as early as 10 days after the first infusion. Significant although smaller benefits were also detected in those with CRP levels ≥ 2 or ≥ 3 mg/L. These improvements persisted variably over the 2-year observational period. No significant benefits were observed in patient reported responses or number of COPD exacerbations between treatment groups.ConclusionIn an inflammatory environment, defined by elevated circulating CRP, remestemcel-L administration yielded at least transient meaningful pulmonary and functional improvements. These findings warrant further investigation of potential MSC-based therapies in COPD and other inflammatory pulmonary diseases.Trial registrationClinicaltrials.gov NCT00683722.

OBJECTIVE: To evaluate short- and long-term outcomes of African American (AA) participants of Scleroderma Lung Studies (SLS) I and II. METHODS: SLS I randomized 158 participants with systemic sclerosis-interstitial lung disease (SSc-ILD) to 1 year of oral cyclophosphamide (CYC) versus placebo. SLS II randomized 142 participants with SSc-ILD to 1 year of oral CYC followed by 1 year of placebo versus 2 years of mycophenolate (MMF). Joint models compared the course of forced vital capacity (FVC) and diffusing capacity for carbon monoxide (DLCO) between AA and non-AA, and Cox proportional hazard models assessed long-term morbidity and mortality outcomes. RESULTS: In SLS I, there was no difference in the course of the FVC or DLCO between AA and non-AA in either treatment arm. In SLS II, AA had an improved course of the FVC compared with non-AA in the CYC arm; in the MMF arm, there was no difference in FVC course. There was no difference in DLCO course in either arm. Time to death and respiratory failure were similar for AA and non-AA in SLS I. There was a trend for improved survival and time to respiratory failure in AA compared with non-AA in SLS II. AA race was not independently associated with mortality in the SLS I or II in the Cox models. CONCLUSION: Data from two randomized controlled trials demonstrated that AA patients with SSc-ILD have similar morbidity and mortality outcomes compared with non-AA patients. These findings contrast with the racial disparities described in prior observational studies and warrant further investigation.

Recent studies have emphasized the difficulty of early detection of chronic obstructive pulmonary disease (COPD) in symptomatic smokers with normal routine spirometry. This includes post-bronchodilator normal forced expiratory volume in 1 second (FEV1)(L)≥80% predicted, forced vital capacity (FVC)(L)≥80% predicted, and FEV1/FVC ≥70% or greater than age corrected lower limit of normal (LLN). However, in COPD the pathologic site of small airway obstruction and emphysema begins in the small peripheral airways ≤2 mm id which normally contribute

Inhaled bronchodilators are central for the treatment of chronic obstructive pulmonary disease (COPD), as they can provide symptom relief and reduce the frequency and severity of exacerbations while improving health status and exercise tolerance. In 2017, glycopyrrolate (GLY) delivered via the eFlow® closed system (CS) nebulizer (nebulized GLY; 25 µg twice daily), was approved by the US Food and Drug Administration for maintenance treatment of moderate-to-very-severe COPD. This approval was based largely on results from the replicate, placebo-controlled, Phase III clinical trials- GOLDEN 3 and 4. In this review, we summarize key findings from secondary analyses of the GOLDEN 3 and 4 studies, and provide a comprehensive overview that may assist both pulmonologists and primary-care providers in their treatment decisions. Comorbidities are common among patients with COPD in clinical practice and may impact bronchodilator efficacy. This review highlights outcomes among subpopulations of patients with comorbidities (e.g., anxiety/depression, cardiovascular disease), and their impact on the efficacy of nebulized GLY. In addition, the efficacy and safety of nebulized GLY across various demographics (e.g., age, gender) and baseline disease characteristics (e.g., disease severity, rescue medication use) are discussed. Real-world outcomes with nebulized GLY, including device satisfaction, healthcare resource utilization, and exacerbations, are also presented. These secondary analyses and real-world data complement the primary results with nebulized GLY from Phase III studies and support the need for the inclusion of patients representative of real-world clinical practice in RCTs. In addition, these data suggest that RCTs for COPD therapies should be complemented with real-world observational studies.

BackgroundAlthough there is some evidence of positive associations between both the glycemic index (GI) and glycemic load (GL) with cancer risk, the relationships with lung cancer risk remain largely unexplored. We evaluated the associations between GI and GL with lung cancer.MethodsThe analyses were performed using data from a population-based case-control study recruited between 1999 and 2004 in Los Angeles County. Dietary factors were collected from 593 incident lung cancer cases and 1026 controls using a modified food frequency questionnaire. GI and GL were estimated using a food composition table. Adjusted odds ratios (ORs) and 95 % confidence intervals (CI) were estimated using unconditional logistic regression adjusting for potential confounders.ResultsDietary GI was positively associated with lung cancer (OR for upper vs. lower tertile = 1.62; 95 % CI: 1.17, 2.25). For histologic subtypes, positive associations were observed between GI and adenocarcinoma (OR for upper vs. lower tertile = 1.82; 95 % CI: 1.22, 2.70) and small cell carcinoma (OR for upper vs. lower tertile = 2.68; 95 % CI: 1.25, 5.74). No clear association between GL and lung cancer was observed.ConclusionThese findings suggest that high dietary GI was associated with increased lung cancer risk, and the positive associations were observed for both lung adenocarcinoma and small cell lung carcinoma. Replication in an independent dataset is merited for a broader interpretation of our results.

ObjectiveTo investigate the prevalence of the MUC5B promoter variant rs35705950 in patients with systemic sclerosis-interstitial lung disease (SSc-ILD) and whether its presence predicts response to immunosuppression with cyclophosphamide (CYC) and mycophenolate (MMF).MethodsSSc-ILD patients who participated in Scleroderma Lung Study (SLS) II (MMF versus CYC) were included in this study (N = 142). TaqMan Genotyping Assays were used to determine the MUC5B rs35705950 single nucleotide polymorphism. Joint models were created to examine how the presence of this variant affected the course of the forced vital capacity (FVC) over 2 years. Linear regression models were used to investigate the relationship between the presence of this variant and the change in quantitative radiographic fibrosis.ResultsAmong 128 participants who were tested for this variant, 18% possessed at least one copy of the MUC5B minor allele. Patients with at least one copy of this allele were similar to those without the allele with respect to age, sex, SSc subtype, ILD disease severity; however, this variant was rare among African Americans (3.7%). The presence of the MUC5B variant did not affect the course of the FVC, nor the change in quantitative radiographic fibrosis, ground glass or ILD scores in either treatment arm.ConclusionIn the context of a randomized controlled trial for SSc-ILD, the presence of the MUC5B variant did not predict disease severity, nor affect treatment response to MMF or CYC. Future studies are needed to determine whether this variant affects ILD progression in other SSc cohorts and in patients receiving anti-fibrotic therapy.

OBJECTIVE: Our objective was to determine if treatment with cyclophosphamide (CYC) and mycophenolate mofetil (MMF) improves patient-reported outcomes (PROs) among patients with systemic sclerosis-related interstitial lung disease (SSc-ILD). METHODS: This study examined PROs in patients with SSc-ILD (N = 142) who participated in the Scleroderma Lung Study II, a randomized controlled trial comparing MMF for 2 years with oral CYC for 1 year followed by 1 year of a placebo. Joint models were created to evaluate the course of PROs over 2 years. The difference in PRO scores from baseline to 24 months was measured, and the percentage of patients meeting the minimum clinically important difference (MCID) was calculated. Correlations between PROs and SSc-ILD disease severity measures were also examined. RESULTS: Treatment with CYC and MMF led to improvements in several PROs with no between-treatment differences. Scores for the Transitional Dyspnea Index (TDI) and St. Georges Respiratory Questionnaire (SGRQ) improved significantly over 2 years, and 29%/24% and 28%/25% of participants in the CYC/MMF groups met or exceeded the MCID estimates for TDI and SGRQ, respectively. At baseline, the forced vital capacity (FVC) percentage predicted (FVC%-predicted) did not correlate with the Baseline Dyspnea Index or SGRQ. However, improvements in the FVC%-predicted were weakly associated with improvements in dyspnea (assessed by the TDI) and SGRQ scores. CONCLUSION: Treatment with CYC and MMF improved overall health-related quality of life in patients with SSc-ILD. The relationship between PRO measures and the FVC was relatively weak, suggesting that PROs provide complementary information about treatment efficacy not captured by changes in the FVC alone in this patient population.

Systemic sclerosis (SSc) is a complex, multiorgan, autoimmune disease. Lung fibrosis occurs in ∼80% of patients with SSc; 25% to 30% develop progressive interstitial lung disease (ILD). The pathogenesis of fibrosis in SSc-associated ILD (SSc-ILD) involves cellular injury, activation/differentiation of mesenchymal cells, and morphological/biological changes in epithelial/endothelial cells. Risk factors for progressive SSc-ILD include older age, male sex, degree of lung involvement on baseline high-resolution computed tomography imaging, reduced DlCO, and reduced FVC. SSc-ILD does not share the genetic risk architecture observed in idiopathic pulmonary fibrosis (IPF), with key risk factors yet to be identified. Presence of anti-Scl-70 antibodies and absence of anti-centromere antibodies indicate increased likelihood of progressive ILD. Elevated levels of serum Krebs von den Lungen-6 and C-reactive protein are both associated with SSc-ILD severity and predict SSc-ILD progression. A promising prognostic indicator is serum chemokine (C-C motif) ligand 18. SSc-ILD shares similarities with IPF, although clear differences exist. Histologically, a nonspecific interstitial pneumonia pattern is commonly observed in SSc-ILD, whereas IPF is defined by usual interstitial pneumonia. The course of SSc-ILD is variable, ranging from minor, stable disease to a progressive course, whereas all patients with IPF experience progression of disease. Although appropriately treated patients with SSc-ILD have better chances of stabilization and survival, a relentlessly progressive course, akin to IPF, is seen in a minority. Better understanding of cellular and molecular pathogenesis, genetic risk, and distinctive features of SSc-ILD and identification of robust prognostic biomarkers are needed for optimal disease management.

Rationale: The role of PI (protease inhibitor) type Z heterozygotes and additional rare variant genotypes in the gene encoding alpha-1 antitrypsin, SERPINA1 (serpin peptidase inhibitor, clade A, member 1), in determining chronic obstructive pulmonary disease risk and severity is controversial.Objectives: To comprehensively evaluate the effects of rare SERPINA1 variants on lung function and emphysema phenotypes in subjects with significant tobacco smoke exposure using deep gene resequencing and alpha-1 antitrypsin concentrations.Methods: DNA samples from 1,693 non-Hispanic white individuals, 385 African Americans, and 90 Hispanics with ≥20 pack-years smoking were resequenced for the identification of rare variants (allele frequency

Systemic sclerosis (SSc) is a complex, multiorgan, autoimmune disease. Lung fibrosis occurs in ∼80% of patients with SSc; 25% to 30% develop progressive interstitial lung disease (ILD). The pathogenesis of fibrosis in SSc-associated ILD (SSc-ILD) involves cellular injury, activation/differentiation of mesenchymal cells, and morphological/biological changes in epithelial/endothelial cells. Risk factors for progressive SSc-ILD include older age, male sex, degree of lung involvement on baseline high-resolution computed tomography imaging, reduced DlCO, and reduced FVC. SSc-ILD does not share the genetic risk architecture observed in idiopathic pulmonary fibrosis (IPF), with key risk factors yet to be identified. Presence of anti-Scl-70 antibodies and absence of anti-centromere antibodies indicate increased likelihood of progressive ILD. Elevated levels of serum Krebs von den Lungen-6 and C-reactive protein are both associated with SSc-ILD severity and predict SSc-ILD progression. A promising prognostic indicator is serum chemokine (C-C motif) ligand 18. SSc-ILD shares similarities with IPF, although clear differences exist. Histologically, a nonspecific interstitial pneumonia pattern is commonly observed in SSc-ILD, whereas IPF is defined by usual interstitial pneumonia. The course of SSc-ILD is variable, ranging from minor, stable disease to a progressive course, whereas all patients with IPF experience progression of disease. Although appropriately treated patients with SSc-ILD have better chances of stabilization and survival, a relentlessly progressive course, akin to IPF, is seen in a minority. Better understanding of cellular and molecular pathogenesis, genetic risk, and distinctive features of SSc-ILD and identification of robust prognostic biomarkers are needed for optimal disease management.

ObjectiveTo examine changes in the extent of specific patterns of interstitial lung disease (ILD) as they transition from one pattern to another in response to immunosuppressive therapy in systemic sclerosis-related ILD (SSc-ILD).MethodsWe evaluated changes in the quantitative extent of specific lung patterns of ILD using volumetric high-resolution computed tomography (HRCT) scans obtained at baseline and after 2 years of therapy in patients treated with either cyclophosphamide (CYC) for 1 year or mycophenolate mofetil (MMF) for 2 years in Scleroderma Lung Study II. ILD patterns included lung fibrosis, ground glass, honeycombing, and normal lung. Net change was calculated as the difference in the probability of change from one ILD pattern to another. Wilcoxon's signed rank test was used to compare the changes.ResultsForty-seven and 50 patients had baseline and follow-up scans in the CYC and MMF groups, respectively. Mean net improvements reflecting favorable changes from one ILD pattern to another in the whole lung in the CYC and MMF groups, respectively, were as follows: from lung fibrosis to a normal lung pattern, 21% and 19%; from a ground-glass pattern to a normal lung pattern, 30% and 28%; and from lung fibrosis to a ground-glass pattern, 5% and 0.5%. The mean overall improvement in transitioning from a ground-glass pattern or lung fibrosis to a normal lung pattern was significant for both treatments (all P < 0.001).ConclusionSignificantly favorable transitions from both ground-glass and lung fibrosis ILD patterns to a normal lung pattern were observed in patients undergoing immunosuppressive treatment for SSc-ILD, suggesting the usefulness of examining these transitions for insights into the underlying pathobiology of treatment response.

Analytic epidemiological studies cover a large spectrum of study methodologies, ranging from noninterventional observational studies (population-based, case-control, or cohort studies) to interventional studies (clinical trials). Herein, we review the different research methodologies or study designs and discuss their advantages and disadvantages in the context of chronic obstructive pulmonary disease (COPD) pharmacotherapy. Although randomized controlled trials (RCTs) are considered the gold standard for evaluating the efficacy and safety of an intervention, observational studies conducted in a real-world scenario are useful in providing evidence on the effectiveness of the intervention in clinical practice; understanding both efficacy and effectiveness is important from the clinicians perspective. Pragmatic clinical trials that use real-world data while retaining randomization bridge the gap between explanatory RCTs and noninterventional observational studies. Overall, different study designs have their associated advantages and disadvantages; together, findings from all types of studies bring about progress in clinical research as elucidated through examples from COPD research in this paper.

Coronavirus disease 2019 (COVID-19), caused by the highly contagious novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a worldwide pandemic and currently represents a major public health issue. COVID-19 has highlighted the need for clear and accurate guidance on the use of aerosol-generating procedures, such as nebulization, for the treatment of patients with respiratory diseases with or without COVID-19. Despite the lack of evidence, there is heightened concern about the potential risk of transmission of SARS-CoV-2 in the form of aerosolized respiratory droplets during the nebulized treatment of patients with COVID-19. Consequently, the use of metered-dose inhalers (MDIs) has risen considerably as an alternative to nebulized therapy, which has led to inadequate supplies of MDIs in some parts of the United States. In this article, we review and discuss the role of nebulization in patients with SARS-CoV-2 and the treatment of noninfected patients with chronic respiratory diseases. The following two important questions are addressed: (1) should nebulized therapy be used in hospital or home settings by patients infected with SARS-CoV-2; and (2) should nebulized therapy be continued in patients already using it for chronic respiratory disease management in hospital or home settings?The reviews of this paper are available via the supplemental material section.

[This corrects the article DOI: 10.2147/COPD.S220164.].

ObjectiveTo investigate the relationship between Krebs von den Lungen 6 (KL-6) and CCL18 levels and the severity and progression of systemic sclerosis (SSc)-related interstitial lung disease (ILD).MethodsPatients enrolled in the Scleroderma Lung Study II (cyclophosphamide [CYC] versus mycophenolate mofetil [MMF]) were included. Baseline and 12-month plasma samples were analyzed by enzyme-linked immunosorbent assay to assess CCL18 and KL-6 levels. The forced vital capacity (FVC) and the diffusing capacity for carbon monoxide (DLco) were measured every 3 months. Joint models were created to investigate the relationship between baseline CCL18 and KL-6 levels and the course of the FVC and DLco over 1 year according to treatment arm.ResultsBaseline KL-6 and CCL18 levels each correlated with the extent of radiographic fibrosis. Levels of both CCL18 and KL-6 declined significantly at 1 year. In both treatment arms (n = 71 for CYC, n = 62 for MMF), a higher baseline KL-6 level predicted progression of ILD based on the course of FVC (P = 0.024 for CYC; P = 0.005 for MMF) and DLco (P < 0.001 for CYC; P = 0.004 for MMF) over 1 year. A higher baseline CCL18 level predicted progression of ILD based on the course of the FVC (P < 0.001 for CYC; P = 0.007 for MMF) and DLco (P = 0.001 for CYC; P < 0.001 for MMF) over 1 year, as well as mortality (P = 0.0008 for CYC arm only).ConclusionIn a rigorously conducted clinical trial for SSc-related ILD, KL-6 and CCL18 levels correlated with ILD severity and declined with immunosuppression. Patients with higher baseline KL-6 and CCL18 levels were more likely to experience disease progression despite treatment. KL-6 and CCL18 levels could be used to identify patients with a progressive ILD phenotype who may benefit from a more aggressive initial treatment approach.

BackgroundSmoking is a major risk factor for COPD and may impact the efficacy of COPD treatments; however, a large proportion of COPD patients continue to smoke following diagnosis.MethodsThis post-hoc analysis of pooled data from the replicate 12-week, placebo-controlled GEM1 and GEM2 studies assessed the impact of smoking status on the efficacy and safety of glycopyrrolate 15.6 μg twice daily vs placebo in patients with moderate-to-severe COPD. Data from 867 patients enrolled in GEM1 and GEM2 were pooled for analysis and grouped by smoking status (57% current smokers, 43% ex-smokers). Forced expiratory volume in 1 s (FEV1) area under the curve from 0 to 12 h, trough FEV1, forced vital capacity, St George's Respiratory Questionnaire (SGRQ) total score, COPD assessment test (CAT) score, transition dyspnea index (TDI) focal score, daily symptom scores, and rescue medication use were assessed in current smokers and ex-smokers. Incidences of adverse events (AEs) and serious AEs (SAEs) were also assessed.ResultsTreatment with glycopyrrolate resulted in significant improvements in all lung function measures, independent of smoking status. In both current and ex-smokers, changes from baseline in trough FEV1 were less marked in patients taking inhaled corticosteroids (ICS) than those not receiving ICS. Changes from baseline in SGRQ total score and rescue medication use were significantly greater with glycopyrrolate compared with placebo, regardless of smoking status. Changes in the CAT score, TDI focal score, and daily symptom scores significantly improved versus placebo, but only in current smokers. Improvements in patient-reported outcomes (PROs) with glycopyrrolate relative to placebo were numerically greater in current smokers than ex-smokers. The incidences of AEs and SAEs were similar regardless of smoking status.ConclusionsIn this post-hoc analysis of GEM1 and GEM2, glycopyrrolate use led to significant improvements in lung function, independent of baseline smoking status; improvements were less marked among patients receiving background ICS, regardless of baseline smoking status. Improvements in PROs were greater with glycopyrrolate than placebo, and the magnitude of changes was numerically greater among current smokers. The safety profile of glycopyrrolate was comparable between current smokers and ex-smokers.

ObjectiveThis study aimed to assess the minimal clinically important differences (MCIDs) for the modified Rodnan skin score (mRSS) using combined data from the Scleroderma Lung Studies (I and II).MethodsMCID estimates for the mRSS at 12 months were calculated using three anchors: change in scores on the Health Assessment Questionnaire- Disability Index from baseline to 12 months, change in scores on the Patient Global Assessment from baseline to 12 months, and answer at 12 month for the Short Form-36 health transition question "Compared to one year ago, how would you rate your health in general now?" We determined the mRSS MCID estimates for all participants and for those with diffuse cutaneous systemic sclerosis (dcSSc). We then assessed associations between MCID estimates of mRSS improvement and patient-reported outcomes, using Student's t test to compare the mean differences in patient outcomes between those who met the MCID improvement criteria versus those who did not meet the improvement criteria.ResultsThe mean (SD) mRSS at baseline was 14.75 (10.72) for all participants and 20.93 (9.61) for those with dcSSc. The MCID estimate for mRSS improvement at 12 months ranged from 3 to 4 units for the overall group (improvement of 20-27% from baseline) and was 5 units for those with dcSSc (improvement of 24% from baseline). Those who met the mRSS MCID improvement criteria had statistically significant improvements in scores on the Short Form-36 Physical Component Summary, the Transition Dyspnea Index, and joint contractures at 12 months.ConclusionMCID estimates for the mRSS were 3-4 units for all participants and 5 units for those with dcSSc. These findings are consistent with previously reported MCID estimates for systemic sclerosis.

Airway inflammation is a major contributing factor in both asthma and chronic obstructive pulmonary disease (COPD) and represents an important target for treatment. Inhaled corticosteroids (ICS) as monotherapy or in combination therapy with long-acting β2-agonists or long-acting muscarinic antagonists are used extensively in the treatment of asthma and COPD. The development of ICS for their anti-inflammatory properties progressed through efforts to increase topical potency and minimise systemic potency and through advances in inhaled delivery technology. Budesonide is a potent, non-halogenated ICS that was developed in the early 1970s and is now one of the most widely used lung medicines worldwide. Inhaled budesonide's physiochemical and pharmacokinetic/pharmacodynamic properties allow it to reach a rapid and high airway efficacy due to its more balanced relationship between water solubility and lipophilicity. When absorbed from the airways and lung tissue, its moderate lipophilicity shortens systemic exposure, and its unique property of intracellular esterification acts like a sustained release mechanism within airway tissues, contributing to its airway selectivity and a low risk of adverse events. There is a large volume of clinical evidence supporting the efficacy and safety of budesonide, both alone and in combination with the fast- and long-acting β2-agonist formoterol, as maintenance therapy in patients with asthma and with COPD. The combination of budesonide/formoterol can also be used as an as-needed reliever with anti-inflammatory properties, with or without regular maintenance for asthma, a novel approach that is already approved by some country-specific regulatory authorities and currently recommended in the Global Initiative for Asthma (GINA) guidelines. Budesonide remains one of the most well-established and versatile of the inhaled anti-inflammatory drugs. This narrative review provides a clinical reappraisal of the benefit:risk profile of budesonide in the management of asthma and COPD.

Page 5, Fig. 2 Key milestones in the development of budesonide.

Airway inflammation is a major contributing factor in both asthma and chronic obstructive pulmonary disease (COPD) and represents an important target for treatment. Inhaled corticosteroids (ICS) as monotherapy or in combination therapy with long-acting β2-agonists or long-acting muscarinic antagonists are used extensively in the treatment of asthma and COPD. The development of ICS for their anti-inflammatory properties progressed through efforts to increase topical potency and minimise systemic potency and through advances in inhaled delivery technology. Budesonide is a potent, non-halogenated ICS that was developed in the early 1970s and is now one of the most widely used lung medicines worldwide. Inhaled budesonide's physiochemical and pharmacokinetic/pharmacodynamic properties allow it to reach a rapid and high airway efficacy due to its more balanced relationship between water solubility and lipophilicity. When absorbed from the airways and lung tissue, its moderate lipophilicity shortens systemic exposure, and its unique property of intracellular esterification acts like a sustained release mechanism within airway tissues, contributing to its airway selectivity and a low risk of adverse events. There is a large volume of clinical evidence supporting the efficacy and safety of budesonide, both alone and in combination with the fast- and long-acting β2-agonist formoterol, as maintenance therapy in patients with asthma and with COPD. The combination of budesonide/formoterol can also be used as an as-needed reliever with anti-inflammatory properties, with or without regular maintenance for asthma, a novel approach that is already approved by some country-specific regulatory authorities and currently recommended in the Global Initiative for Asthma (GINA) guidelines. Budesonide remains one of the most well-established and versatile of the inhaled anti-inflammatory drugs. This narrative review provides a clinical reappraisal of the benefit:risk profile of budesonide in the management of asthma and COPD.

Epinephrine HFA (Primatene® Mist) is a newly formulated asthma metered dose inhaler developed to replace the previous Primatene® Mist CFC. The formulation of Epinephrine HFA contains thymol, a substance recognized to be safe by the FDA. Although the content of thymol contained in Epinephrine HFA is much lower compared to many common foods and medications available, there are no known nonclinical data about the chronic toxicity of thymol through inhalation. Two sequential 6-month studies of identical design were conducted to assess the chronic toxicity of inhaled thymol in mice. Four treatment groups, (a) Air; (b) vehicle control; (c) Article-1 (thymol 0.1%); and (d) Article-2 (thymol 0.5%) were assessed in 128 mice for 26 weeks. The mice were sacrificed at the end of the treatment period and a histopathologic evaluation was performed with respect to lungs, bronchial lymph nodes, nasal passages/nasopharynx, and trachea. Forty-five pathologic assessment parameters (PAPs) were evaluated. In total, 5591 data points from 487 mouse organs were assessed. Chronic toxicity index was calculated for 16 PAPs that had multiple histopathologic abnormal observations. The t tests were conducted for these 16 PAPs (Articles-1 and 2 versus Air and vehicle control, respectively), and all P-values were greater than .05 indicating no significant differences between all treatment groups. An evaluation was also conducted for 25 PAPs that had only a very small number of pathologic abnormalities. No significant differences for chronic toxicity were found when comparing mice under long-term repeated exposure of high doses of inhaled thymol and mice that inhaled no thymol.

Thymol is generally recognized as a safe substance by the FDA and has been widely used in the pharmaceutical, food, and cosmetic industries. Pharmacokinetic (PK) studies of thymol have been previously conducted for oral administration, but there has been no PK study for inhalation administration or intravenous (IV) injection. This study aims at exploring and comparing the inhalation and IV PK profile of thymol in a mouse model. The inhalation PK for mouse model was corrected with fur/skin absorption. Thirty-two male CD-1 mice were randomized into two study arms, Arm-A for intravenous (n = 16) and Arm-B for inhalation (n = 16). The amount of thymol in the mouse serum was measured for Arm-A and for Arm-B at the highest dose. Furthermore, 48 mice were utilized for fur/skin absorption of thymol. In total, 320 mouse serum samples for thymol were analyzed by LC/MS method. After inhalation, the peak concentration of thymol in mouse serum was 42.3 ng/mL (Cmax ) and occurred at 2 minutes (tmax ). The AUC of the inhaled thymol at 0-60 minutes (AUC0-60) was 464 ng/mL/min. From 10-60 minutes post-dose, the PK inhalation curve appeared to be higher than that for the IV injection. This is likely attributed to the effect of absorption of thymol through the fur/skin of mice. After an adjustment by fur/skin absorption, the PK profile for net inhalation closely matched the two-compartment model. In fact, the bioavailability for the net inhalation of thymol was 74% and 77% relative to that for IV injection per AUC0-60min and AUC0-infinite, respectively.