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Table 2 Bronchoalveolar lavage (BAL) cohort: Demographic and clinical characteristics and ADAM15 levels

From: ADAM15 expression is increased in lung CD8+ T cells, macrophages, and bronchial epithelial cells in patients with COPD and is inversely related to airflow obstruction

Characteristics Non-smokersa (N = 6) Smokersa (N = 19) COPD Patients (N = 14) P valuec
Number of males (%) 5 (83) 7 (37) 7 (50) NS
Age (years) 59 (46–73) 64 (51–75) 66 (60–74) NS
Pack-yrs. of smoking 0 29 (12–68) 43 (7–160) P < 0.001d
Number of current smokers (%) 0 (0) 7 (37) 6 (43) NS
FEV1(% of predicted)b 94 (83–106) 92 (71–114) 59 (10–89) P < 0.001e
FEV1/FVC (% of predicted)b 78 (74–82) 78 (72–88) 55 (41–69) P < 0.001f
ADAM15mRNA Levels in AMs (Normalized to Levels in AMs From Non-smokers) 1 ± 0.3 1.2 ± 0.5 2 ± 0.4 P < 0.001g
ADAM15 Protein Levels in AMs (% of Levels in AMs From Non-smokers) 100 ± 26 130 ± 27 234 ± 50 P < 0.001h
sADAM15 Protein Levels in BALF (pg/ml) 7.4 (0–23) 10 (0–25) 7 (0–58) NSi
  1. The table shows the demographic and clinical characteristics of the patients with COPD, smokers without COPD, and non-smoker controls who underwent a bronchoscopy and bronchoalveolar lavage (BAL) as part of another research study. Patients with COPD were sub-divided according to Global Initiative for Obstructive Lung Disease (GOLD) criteria (4 subjects had GOLD stage I, 7 subjects had GOLD stage II, and 3 had GOLD stage III disease). Patients with GOLD stage IV disease were not including in the research study due to the risks associated with a bronchoscopy in this population. BAL was performed as described in Methods, and the BAL cell fraction was separated from the BALF fraction using centrifugation. BALF soluble ADAM15 (sADAM15) levels were measured using an ELISA. Alveolar macrophages (AMs) were isolated from BAL samples as described in Methods. ADAM15 steady state mRNA levels were measured in the AM samples using a quantitative real time reverse transcription polymerization chain reaction assay and ADAM15 protein levels were measured using Western blotting and densitometry. ADAM15 mRNA and protein levels in the AMs from the smokers and COPD patients were normalized to the mRNA or protein levels, respectively, in AMs from non-smokers
  2. Data are presented as median (interquartile range) for data that were not normally distributed or mean ± SD for data that were normally distributed
  3. a Non-smokers were all never-smokers. Smokers were defined as subjects who had a > 10 pack-years of smoking history. Current smokers were defined as active smokers at the time of the bronchoscopy or had stopped smoking < 1 year before the bronchoscopy was performed
  4. b All COPD patients had forced expiratory volume in 1 s/forced vital capacity ratio (FEV1/FVC) < 0.7 whereas smokers without COPD and non-smoker controls had FEV1/FCV > 0.7
  5. c Categorical variables were analyzed with z-test. Statistical analyses included One-Way ANOVA tests for continuous variables (age, FEV1% predicted, FEV1/FCV, and pack-years of smoking history) followed by pair-wise comparisons using 2 tailed Student’s t-tests for data that were normally distributed or Mann-Whitney U tests for that were not normally distributed
  6. d The pack-years of smoking histories of the COPD patients were not significantly different from those of the smokers (P = 0.177). The pack-years of smoking histories of the COPD patients and the smokers were significantly different from those of the non-smoker group by design (P < 0.001 for both comparisons)
  7. e The FEV1 values for the COPD patients were significantly lower than those of the smokers and non-smokers by design (P < 0.001 for both comparisons). The FEV1 values for the smokers were not significantly different from those for the non-smoker groups (P = 0.7)
  8. f The FEV1/FVC ratios for the COPD patients were significantly lower than those of the smoker and non-smoker groups by design (P < 0.001 for both comparisons). The FEV1/FVC ratios of the smokers were not significantly different from those of the non-smokers (P = 0.65)
  9. gADAM15 steady state mRNA levels in AMs normalized to the mean value in the non-smoker group. P values were adjusted to correct for differences in pack-years of smoking history between the COPD patients and controls using an ordinal logistic regression model. After adjusting for these covariates, ADAM15 mRNA levels in AMs from patients with COPD remained significantly different from those in AMs from non-smoker and smoker groups. The adjusted P values are shown in the Table. There were no significant differences in ADAM15 steady state mRNA levels in AMs between the non-smoker and smoker groups
  10. h ADAM15 protein levels in AMs normalized to the mean value in the non-smoker group. P values were adjusted to correct for differences in pack-years of smoking histories between the COPD and control groups using an ordinal logistic regression model. After adjusting for these covariates, ADAM15 protein levels in AMs from the patients with COPD remained significantly different from those in AMs from the non-smoker and smoker groups. The adjusted P values are shown in the Table. There were no significant differences in ADAM15 protein levels in AMs between the non-smoker and smoker groups
  11. i Soluble ADAM15 levels in the BALF samples are shown. P values were adjusted to correct for differences in pack-years of smoking history between the patients with COPD and controls using an ordinal logistic regression model. After adjusting for these covariates, there were no significant differences in BALF sADAM15 levels between patients with COPD and the control groups
  12. NS not significant