Bronchial hyperresponsiveness, airway inflammation, and reversibility in patients with chronic obstructive pulmonary disease

Figures & data

Table 1 Clinical and functional characteristics of the studied patients

	COPD patients (n=29)
Age (years)	67±9
Sex (female/male)	6/23
Current smoker, n (%)	13 (45)
Smoking consumption (pack/year)	51±34
FEV1 (% predicted)	68±17
VC (% predicted)	98±14
FEV1/VC (%)	54±10
RV (% predicted)	155±39
TLC (% predicted)	118±17
RV/TLC (%)	51±7
IC (L)	2.6±0.4
Change in FEV1 (%)	8.6±8.5
BMI (kg/m^2)	27±4
Exacerbations previous year	0.7±0.8
Symptom score	8.1±4.2
Cough	21/29
Wheezing	8/29
Dyspnea	15/29
Sputum	24/29
Nocturnal symptoms	10/29

Note: Values are expressed as mean ± SD.

Abbreviations: FEV₁, forced respiratory volume in 1 second; VC, vital capacity; RV, residual volume; TLC, total lung capacity; IC, inspiratory capacity; BMI, body mass index; SD, standard deviation.

Table 2 Induced sputum cells in mild and moderate COPD subjects

	All patients (n=29)	Patients with BHR (n=12)	Patients without BHR (n=17)	P-value*
Macrophages (%)	6.6 (4.6–9.5)	7.5 (2.5–8.6)	6.6 (5.3–10.9)	0.578
Neutrophils (%)	78 (73–84)	78.1 (68.1–85.5)	79 (76.3–83)	0.703
Eosinophils (%)	2 (1–4.6)	3.4 (1.2–5.2)	1.6 (0.8–2.1)	0.046*
Lymphocytes (%)	0.2 (0–0.4)	0.1 (0–0.4)	0.2 (0–0.5)	0.577
Epithelial cells (%)	11.5 (5.6–15.6)	10.7 (5.3–18.1)	12.4 (5.6–15.1)	0.836

Notes: Values are expressed as median (interquartile range). Comparisons between variables were determined by unpaired t-test.

* Patients with BHR vs patients without BHR.

Abbreviation: BHR, bronchial hyperresponsiveness.

Figure 1 Venn-diagram showing the percentage distribution of bronchial reversibility, bronchial hyperresponsiveness, and sputum eosinophilia in the COPD subjects enrolled in the study.

Table 3 BHR, reversibility, symptom score, and exacerbations in COPD patients considered altogether and divided according to sputum eosinophils

	All patients (n=29)	Patients with eosinophils ≥3% (n=9)	Patients with eosinophils <3% (n=20)	P-value*
BHR (μg)	1,600 (208–1,600)	100 (32–1,600)	1,600 (990–1,600)	0.010
Reversibility (change FEV1 in %)	5.6 (0.3–14.6)	3.0 (0–21.1)	5.9 (1.1–13.2)	0.862
Symptom score	8.0 (5.0–10.0)	8.0 (8.0–9.5)	6.5 (4.2–9.5)	0.031
Exacerbations previous year	0.0 (0.0–1.0)	1.0 (1.0–1.5)	0.0 (0.0–1.0)	0.019

Notes: Values are expressed as median (interquartile range). Comparisons between variables were determined by unpaired t-test.

* Patients with eosinophils ≥3% vs patients with eosinophils <3%.

Abbreviations: BHR, bronchial hyperresponsiveness; FEV₁, forced respiratory volume in 1 second.

Figure 2 Correlation between the cumulative dose of methacholine (PD₂₀) and the score of COPD symptoms questionnaire (r_s=−0.76, P=0.005) (A), and the number of exacerbations in the previous year (r_s=−0.59, P=0.021) (B).

Figure 3 Correlation between changes in post-bronchodilator FEV₁ (% baseline) and sputum eosinophils (%) (r_s=0.82, P=0.003).

Abbreviation: FEV₁, forced respiratory volume in 1 second.