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Table 2 Characteristics of patients with asthma classified by DNA concentration

From: Raised sputum extracellular DNA confers lung function impairment and poor symptom control in an exacerbation-susceptible phenotype of neutrophilic asthma

Characteristic

Low-eDNA

(n = 95)

High-eDNA

(n = 39)

P-value

Age, years

52 (44–63)

51 (43–59)

0.57

Sex, % male

49

41

0.44

BMI, kg/m2

27.3 (24.0–29.0)

26.3 (23.8–34.4)

0.58

Smoking history %

20

27

0.37

Current smokers, %

9

10

1.0

Severe asthma, %

41

64

0.021

Severe exacerbations in last 12 months, %

49

74

0.012

ICS dose, µg

450 (250–950)

500 (450–1000)

0.026

OCS use, %

20

33

0.12

OCS dose; mg

7.5 (5–11)

12 (10–15)

0.14

Blood cell counts, 103/µl

 Eosinophils

245 (140–477)

190 (135–450)

0.56

 Neutrophils

4035 (3302–5758)

4810 (3415–6135)

0.24

Sputum cell counts

 Eosinophils, 106/ml

0.03 (0.01–0.14)

0.06 (0.01–0.24)

0.29

 Eosinophils, %*

1.5 (0.4–5.1)

2.0 (0.35–14.1)

0.87

 Neutrophils, 106/ml

0.81(0.31–1.83)

2.5 (1.0–5.8)

 < 0.0001

 Neutrophils, %*

48 (30–61)

65 (40–77)

0.005

 Macrophages, 106/ml

0.56(0.36–0.93)

0.67 (0.37–1.1)

0.43

 Macrophages, %*

37 (18–56)

19 (11–34)

0.002

Sputum cell viability, %

80 (71–87)

80 (70–88)

0.93

Duration of sputum induction, min

21 (14–21)

21 (14–21)

0.30

FeNO, ppb

25 (15–46)

22 (11–35)

0.1

FEV1, %

87 (74–99)

76 (59–87)

0.002

FVC, %

109 (96–116)

104 (90–112)

0.06

FEV1/FVC, %

68 (61–73)

62 (54–72)

0.059

FEF50, %

58 (38–78)

37 (24–61)

0.004

FEF25–75, (l/s)

1.74 (1.2–2.3)

1.19 (0.64–2.0)

0.016

R20, KPa/l/s

0.32 (0.27–0.38)

0.33 (0.28–0.41)

0.29

R5, KPa/l/s

0.40 (0.35–0.50)

0.49 (0.38–0.62)

0.043

R5-20, %

32 (16–54)

51 (20–80)

0.058

X5Hz, KPa/l/s

− 0.12 (− 0.18–0.09)

− 0.20 (− 0.26–0.13)

 < 0.001

RV, %

118 (103–132)

132 (107–164)

0.015

RV/TLC, %

36 (33–42)

41 (37–48)

0.012

sReff, %

98 (75–138)

133 (89–189)

0.016

LCI

6.1 (5.6–6.6)

6.9 (6.2–7.9)

 < 0.001

  1. Data are reported in median (interquartile range)
  2. BMI body mass index, ICS inhaled corticosteroids, ICS dose fluticasone equivalent, OCS oral corticosteroids, FeNO fractional exhaled nitric oxide, FEV1 forced expiratory volume in first second, FVC forced vital capacity, FEF50% and FEF25–75 mean forced expiratory flow at 50% and between 25 and 75% of the forced vital capacity, R20 proximal airway resistance at 20 Hz, R5-20 small airway resistance (total lung resistance – large airway resistance), X5 lung reactance at 5 Hz, RV residual volume, TLC total lung capacity, sReff specific effective airway resistance, LCI lung clearance index from multiple breath washout
  3. *Sputum cell counts percentage of non-squamous cells