Airway inflammation in Japanese COPD patients compared with smoking and nonsmoking controls

Figures & data

Table 1 Summary of demographics and spirometry measurements

Demographics and measurements	Nonsmoker control	Smoker control	COPD
Participants, n	20	30	47
Demographics
Age, years	59.0±10.2	62.7±12.1	70.8±8.1
Sex, males/females	10/10	28/2	45/2
Height, cm	160.6±7.3	165.8±7.5	163.5±6.7
Weight, kg	62.3±11.0	66.6±10.0	62.3±9.6
Smoking history
Current/former/never	0/3/17	9/21/0	13/34/0
Number of pack-years	0.34±0.3	57.3±105.9	62.3±44.7
Spirometry
FVC, L	3.03±0.69	3.72±0.94	3.18±0.76
FEV1, L	2.47±0.55*	2.91±0.80†	1.92±0.56
FEV1, % predicted	95.0±11.7*	96.5±16.9†	71.3±17.4
FEV1/FVC	81.8±6.8†	78.1±5.6†	60.2±9.1
Whole-breath Impulse Oscillation System results
R5, kPa/L/second	0.283±0.113‡	0.242±0.121¶	0.341±0.149
R20, kPa/L/second	0.248±0.089§	0.219±0.076	0.262±0.078
X5, kPa/L/second	−0.112±0.03§	−0.106±0.09‡	−0.170±0.12

Notes: Demographic data are shown as number of subjects or raw means ± standard deviation, as appropriate. Spirometry data are shown as number of subjects or adjusted means ± standard error, as appropriate. The Dunnett’s test was conducted by comparing with each adjusted mean values.

* P<0.0005 (difference between COPD and nonsmoker control or smoker control groups, by the Dunnett’s test).

† P<0.0001 (difference between COPD and nonsmoker control or smoker control groups, by the Dunnett’s test).

‡ P<0.01 (difference between COPD and nonsmoker control or smoker control groups, by the Dunnett’s test).

¶ P<0.005 (difference between COPD and nonsmoker control or smoker control groups, by the Dunnett’s test).

§ P<0.05 (difference between COPD and nonsmoker control or smoker control groups, by the Dunnett’s test).

Abbreviations: COPD, chronic obstructive pulmonary disease; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity.

Table 2 Summary of inflammatory cells and biomarkers in sputum and blood

Inflammatory biomarkers	Nonsmoker control	Smoker control	Chronic obstructive pulmonary disease
Participants, n	20	30	47
Inflammatory cells (sputum)
Total cell count, ×10^5 cells/mL	39.5±30.4	45.8±40.4	66.5±80.8
Neutrophil count, ×10^5 cells/mL	24.6±21.5	32.7±32.1	53.6±73.6
Macrophage count, ×10^5 cells/mL	12.3±21.6	9.5±10.0	8.7±9.1
Sputum neutrophils, %	67.4±24.3	69.5±20.3	76.3±15.7
Sputum macrophages, %	25.4±23.7	23.1±18.0	16.6±13.3
Biomarkers (sputum)
IL-8, pg/mL	336.0	263.0*	551.0
MMP-9, ng/mL	80.0	90.0	130.0
SP-A, ng/mL	95.16	140.0	158.0
SP-D, ng/mL	21.1	24.1	36.7
KL-6, U/mL	42.8	44.5	71.5
Biomarkers (serum)
IL-8, pg/mL	5.5	5.4	6.0
hs-CRP, ng/dL	327.0	500.0	594.0
CC-16, ng/mL	5.6	6.6	8.5
SP-A, ng/mL	27.0	38.4	39.5
SP-D, ng/mL	45.5	65.2	59.6
KL-6, U/mL	209.5	248.5	285.5
Biomarkers (plasma)
Fibrinogen, mg/dL	289.0	303.5	300.0

Notes: Sputum inflammatory cell and serum biomarker data are shown as mean ± standard deviation; sputum biomarker data are shown as median value. The nonparametric Dunnett’s test was conducted by comparing with each raw median value.

* P<0.05 (difference between patients with COPD and smoker control patients, by the nonparametric Dunnett’s test).

Abbreviations: IL-8, interleukin 8; MMP-9, matrix metalloproteinase 9; SP-A, surfactant protein A; SP-D, surfactant protein D; KL-6, Krebs von den Lungen 6; hs-CRP, high-sensitivity C-reactive protein; CC-16, clara cell 16.

Table 3 Summary of correlation between sputum inflammatory cell counts and sputum biomarkers in patients with COPD

COPD (N=47)	Sputum
	IL-8, pg/mL	MMP-9, ng/mL	SP-A, ng/mL	SP-D, ng/mL	KL-6, U/mL
Sputum
Number of total cells, ×10^5 cells/ml	0.3493*	0.5337†	0.1655	0.1077	0.2329
Number of neutrophils, ×10^5 cells/ml	0.3156*	0.5073†	0.1466	0.0967	0.1908
Number of macrophages, ×10^5 cells/ml	0.2758	0.3038*	0.1977	0.2576	0.4058‡

Notes:

* P<0.05,

‡ P<0.01,

† P<0.001 (correlation between variables, by Spearman’s rank correlation coefficient).

Abbreviations: COPD, chronic obstructive pulmonary disease; IL-8, interleukin 8; MMP-9, matrix metalloproteinase 9; SP-A, surfactant protein A; SP-D, surfactant protein D; KL-6, Krebs von den Lungen 6.

Table 4 Summary of correlation coefficient between sputum inflammatory cell counts and serum biomarkers in COPD patients

COPD (N=47)	Serum
	IL-8, pg/mL	KL-6, U/mL	CC-16, ng/mL	SP-A, ng/mL	SP-D, ng/mL	hs-CRP, ng/dL
Sputum
Number of total cells, ×10^5 cells/ml	−0.0486	0.1990	0.4515*	−0.0395	0.3241	0.2175
Number of neutrophils, ×10^5 cells/ml	−0.0360	0.2163	0.4371*	−0.0138	0.3078	0.2155
Number of macrophages, ×10^5 cells/ml	−0.0713	0.0227	0.2679	−0.0013	0.1786	0.1200

Notes:

* P<0.005 (correlation between variables, by Spearman’s rank correlation coefficient).

Abbreviations: COPD, chronic obstructive pulmonary disease; IL-8, interleukin 8; KL-6, Krebs von den Lungen 6; CC-16, clara cell 16; SP-A, surfactant protein A; SP-D, surfactant protein D; hs-CRP, high sensitivity c-reactive protein.