Inflammatory biomarkers in asthma-COPD overlap syndrome

Figures & data

Table 1 Characteristics of the study patients (n=257)

Age, years	75 (10)
Female	21 (8.2)
BMI, kg/m^2	23.3 (4.6)
Smoking history, pack-years	52.0 (35.1)
Rhinitis	8 (3.1)
FEV1, L	1.50 (0.93)
%FEV1, %	63.1 (32.9)
FVC, L	3.03 (1.32)
GOLD stage
1	54 (21.0)
2	122 (47.5)
3	49 (19.1)
4	32 (12.4)
mMRC dyspnea scale grade	1 (2)
CAT score	5 (6.5)
Regular medication
LAMA	195 (75.9)
LABA	48 (18.7)
ICS	8 (3.1)
LAMA/LABA	21 (8.2)
ICS/LABA	105 (40.9)
Theophylline	31 (12.1)
Home oxygen therapy	38 (14.8)
Severe exacerbation in previous year	18 (7.0)

Notes: Data are shown as median (interquartile range) or number (%). Used with the permission of the Medical Research Council.¹⁶

Abbreviations: BMI, body mass index; CAT, COPD assessment test; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting beta-agonist; LAMA, long-acting muscarinic antagonist; mMRC, modified Medical Research Council.

Table 2 Characteristics of patients with and without ACOS

Characteristic	ACOS (+) (n=37)	ACOS (−) (n=220)	P-value
Age, years	71.3±7.5	75.0±7.0	0.003
Female	4 (10.8)	17 (7.7)	0.527
BMI, kg/m^2	24.0±3.8	23.4±3.8	0.331
Smoking history, pack-years	47.4±27.4	58.9±27.3	0.019
Rhinitis	3 (8.1)	5 (2.3)	0.092
FEV1, L	1.68±0.69	1.51 ±0.65	0.152
%FEV1, %	64.4±21.9	61.4±22.1	0.441
FVC, L	3.32±0.99	3.09± 1.73	0.428
GOLD stage			0.421
1	9 (24.3)	45 (20.5)
2	18 (48.6)	104 (47.3)
3	7 (18.9)	42 (19.1)
4	3 (8.1)	29 (13.2)
mMRC dyspnea scale score	0.9±0.9	1.1± 1.0	0.193
CAT score	5.6±4.0	7.0±6.3	0.443
Regular medicationa
LAMA	32 (86.5)	184 (83.6)	0.661
LABA	30 (81.1)	143 (65.0)	0.054
ICS	32 (86.5)	81 (36.8)	<0.001
Theophylline	10 (27.0)	21 (9.5)	<0.001
Home oxygen therapy	3 (8.1)	35 (15.9)	0.216
Severe exacerbation in prior year	1 (2.7)	17 (7.7)	0.268

Notes: Data are shown as mean ± SD or number (%). Used with the permission of the Medical Research Council.¹⁶

a Medication could be used alone or in combination. Differences between groups were assessed by using the Student’s t test or Mann-Whitney U test for continuous variables. Distribution of GOLD staging between patients with and without ACOS was analysed by using the Kruskal-Wallis test. P<0.05 was considered statistically significant.

Abbreviations: ACOS, asthma-COPD overlap syndrome; BMI, body mass index; CAT, COPD assessment test; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; GOLD, Global Initiative for Chronic Obstructive Lung Disease; ICS, inhaled corticosteroid; LABA, long-acting beta-agonist; LAMA, long-acting muscarinic antagonist; mMRC, modified Medical Research Council; SD, standard deviation.

Table 3 Inflammatory biomarkers in patients with and without ACOS

Biomarker	ACOS (+) (n=37)	ACOS (−) (n=220)	P-value
FENO level
<25 ppb	12 (32.4)	161 (73.2)	<0.001
>50 ppb	10 (27.0)	6 (2.7)	<0.001
Blood eosinophils
≥500/mm^3	6 (16.2)	16 (7.3)	0.104
>2%	31 (83.8)	138 (62.7)	0.014
Total serum IgE level >173 IU/mL	19 (51.4)	65 (29.5)	0.013
Presence of antigen-specific IgE	21 (56.8)	63 (28.6)	0.001

Notes: Data are shown as number (%). Associations between categorical variables were evaluated by using Fisher’s exact test. P<0.05 was considered statistically significant.

Abbreviations: ACOS, asthma-COPD overlap syndrome; FENO, fractional exhaled nitric oxide; IgE, immunoglobulin E; ppb, parts per billion.

Figure 1 Inflammatory biomarkers in patients with and without ACOS.

Notes: (A) FENO level, (B) blood eosinophil count, (C) percentage of blood eosinophils, (D) total serum IgE level. The error bars represent the standard deviation. Differences between groups were assessed by using the Student’s t test. The value of total serum IgE level was log transformed because the variables were not normally distributed; the results are expressed as geometric mean values. P<0.05 was considered statistically significant: *P<0.05, **P<0.01, and ***P<0.001.
Abbreviations: ACOS, asthma-COPD overlap syndrome; FENO, fractional exhaled nitric oxide; ppb, parts per billion; IgE, immunoglobulin E.

MahlerDAWellsCKEvaluation of clinical methods for rating dyspneaChest19889335805863342669

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