A New Bronchodilator Response Grading Strategy Identifies Distinct Patient Populations

Rationale: A positive bronchodilator response (BDR) according to American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines require both 200 ml and 12% increase in forced expiratory volume in 1 second (FEV1) or forced vital capacity (FVC) after bronchodilator inhalation. This dual criterion is insensitive in those with high or low FEV1. Objectives: To establish BDR criteria with volume or percentage FEV1 change. Methods: The largest FEV1 and FVC were identified from three pre- and three post-bronchodilator maneuvers in COPDGene (Genetic Epidemiology of COPD) participants. A total of 7,741 individuals with coefficient of variation less than 15% for both FEV1 and FVC formed bronchodilator categories of FEV1 response: negative (≤0.00% or ≤0.00 L), minimal (>0.00% to ≤9.00% or >0.00 L to ≤0.09 L), mild (>9.00% to ≤16.00% or >0.09 L to ≤0.16 L), moderate (>16.00% to ≤26.00% or >0.16 L to ≤0.26 L), and marked (>26.00% or >0.26 L). These response size categories are based on empirical limits considering average FEV1 increase of approximately 160 ml and the clinically important difference for FEV1. To compare flow and volume response characteristics, BDR-FEV1 category assignments were applied for the BDR-FVC response. Results: Twenty percent met mild and 31% met moderate or marked BDR-FEV1 criteria, whereas 12% met mild and 33% met moderate or marked BDR-FVC criteria. In contrast, only 20.6% met ATS/ERS positive criteria. Compared with the negative BDR-FEV1 category, the minimal, mild, moderate, and marked BDR-FEV1 categories were associated with greater 6-minute-walk distance and lower St. George’s Respiratory Questionnaire and modified Medical Research Council dyspnea scale scores. Compared with negative BDR, moderate and marked BDR-FEV1 categories were associated with fewer exacerbations, and minimal BDR was associated with lower computed tomography airway wall thickness. Compared with the negative category, all BDR-FVC categories were associated with increasing emphysema percentage and gas trapping percentage. Moderate and marked BDR-FVC categories were associated with higher St. George’s Respiratory Questionnaire scores but fewer exacerbations and lower dyspnea scores. Conclusions: BDR grading by FEV1 volume or percentage response identified subjects otherwise missed by ATS/ERS criteria. BDR grades were associated with functional exercise performance, quality of life, exacerbation frequency, dyspnea, and radiological airway measures. BDR grades in FEV1 and FVC indicate different clinical and radiological characteristics

European Respiratory Society International Congress 2018: four shades of epidemiology and tobacco control

In this article, early career members and experienced members of the Epidemiology and Environment Assembly of the European Respiratory Society highlight and summarise a selection of six sessions from the Society’s annual congress, which in 2018 was held in Paris, France. The topics covered in these sessions span from cutting-edge molecular epidemiology of lung function to clinical, occupational and environmental epidemiology of respiratory disease, and from emergent tobacco products to tobacco control

Serum CCL-18 level is a risk factor for COPD exacerbations requiring hospitalization

Asli Gorek Dilektasli,1 Ezgi Demirdogen Cetinoglu,1 Esra Uzaslan,1 Ferah Budak,2 Funda Coskun,1 Ahmet Ursavas,1 Ilker Ercan,3 Ercument Ege1 1Department of Pulmonary Disesaes, 2Department of Immunology, 3Department of Biostatistics, Uludag University Faculty of Medicine, Bursa, Turkey Introduction: Chemokine (C-C motif) ligand 18 (CCL-18) has been shown to be elevated in chronic obstructive pulmonary disease (COPD) patients. This study primarily aimed to evaluate whether the serum CCL-18 level differentiates the frequent exacerbator COPD phenotype from infrequent exacerbators. The secondary aim was to investigate whether serum CCL-18 level is a risk factor for exacerbations requiring hospitalization. Materials and methods: Clinically stable COPD patients and participants with smoking history but normal spirometry (NSp) were recruited for the study. Modified Medical Research Council Dyspnea Scale, COPD Assessment Test, spirometry, and 6-min walking test were performed. Serum CCL-18 levels were measured with a commercial ELISA Kit. Results: Sixty COPD patients and 20 NSp patients were recruited. Serum CCL-18 levels were higher in COPD patients than those in NSp patients (169 vs 94 ng/mL, P<0.0001). CCL-18 level was significantly correlated with the number of exacerbations (r=0.30, P=0.026), although a difference in CCL-18 values between infrequent and frequent exacerbator COPD (168 vs 196 ng/mL) subgroups did not achieve statistical significance (P=0.09). Serum CCL-18 levels were significantly higher in COPD patients who had experienced at least one exacerbation during the previous 12 months. Overall, ROC analysis revealed that a serum CCL-18 level of 181.71 ng/mL could differentiate COPD patients with hospitalized exacerbations from those who were not hospitalized with a 88% sensitivity and 88.2% specificity (area under curve: 0.92). Serum CCL-18 level had a strong correlation with the frequency of exacerbations requiring hospitalization (r=0.68, P<0.0001) and was found to be an independent risk factor for hospitalized exacerbations in the multivariable analysis. Conclusion: CCL-18 is a promising biomarker in COPD, as it is associated with frequency of exacerbations, particularly with severe COPD exacerbations requiring hospitalization, as well as with functional parameters and symptom scores. Keywords: COPD, frequent exacerbator, hospitalized exacerbation, PARC/(CCL-18

A Novel Spirometric Measure Identifies Mild COPD Unidentified by Standard Criteria

Rationale: In chronic obstructive pulmonary disease both smaller and larger airways are affected. Forced expiratory volume in one second (FEV1) mainly reflects large airways obstruction, while the later fraction of forced exhalation reflects reduction in terminal expiratory flow. Objective: To evaluate the relationship between spirometric ratios, including the ratio of forced expiratory volume in 3 and 6 seconds (FEV3/FEV6), and small airway measures and gas trapping in quantitative chest computed tomography (CT), and clinical outcomes in the COPD Gene cohort. Methods: 7,853 current and ex-smokers were evaluated for airflow obstruction using recently defined linear iteratively-derived equations of Hansen et al.1 11 to determine lower limits of normal equations for pre-bronchodilator FEV1/FVC, FEV1/FEV6, FEV3/FEV6 and FEV3/FVC. General linear and ordinal regression models were applied to the relation between pre-bronchodilator spirometry and radiologic and clinical data. Main Results: Of the 10,311 participants included in the COPDGene Phase 1 study, participants with incomplete quantitative CT or relevant spirometric data were excluded, resulting in 7,853 participants in the present study. Of 4,386 participants with ratio of FEV1 to forced vital capacity (FEV1/FVC) greater than lower limit of normal, 15.4% had abnormal FEV3/FEV6. Compared to participants with normal FEV3/FEV6 and FEV1/FVC, abnormal FEV3/FEV6 was associated with significantly greater gas trapping, St. George Respiratory Questionnaire score, mMRC dyspnea score, BODE index, and shorter six-minute walking distance (all P < 0.0001), but not CT22 evidence of emphysema. Conclusions: Current and ex-smokers with pre-bronchodilator FEV3/FEV6 1 < lower limit of normal as the sole abnormality identifies a distinct population with evidence of small airway disease in quantitative CT, impaired indices of physical function and quality of life otherwise deemed normal by current spirometric definition

European Respiratory Society International Congress 2018: Four shades of epidemiology and tobacco control

In this article, early career members and experienced members of the Epidemiology and Environment Assembly of the European Respiratory Society (ERS) highlight and summarise a selection of six sessions from the society’s annual congress, which in 2018 was held in Paris. The topics covered in these sessions span from cutting-edge molecular epidemiology of lung function to environmental, occupational and clinical epidemiology of respiratory disease and from emergent tobacco products to tobacco control