Figures
- Figure 1–
Demographic, functional and inflammatory characteristics of patients according to their local and systemic eosinophil count. FEV1: forced expiratory volume in 1 s; FVC; forced vital capacity; BHR: bronchial hyperresponsiveness; FeNO: exhaled nitric oxide fraction; QoL: quality of life.
- Figure 2–
Asthma Control Questionnaire (ACQ) score according blood and sputum eosinophil count. The presence of both local and systemic eosinophilic inflammation was associated with lower asthma control in the a) retrospective (n=508) and b) prospective cohort (n=250). Data are presented as mean±sem.
- Figure 3–
Exhaled nitric oxide fraction (FeNO) levels in patients classified according to the presence and/or absence of blood and sputum eosinophilia. Patients exhibiting both local and systemic inflammation had the highest level of FeNO (n=508). The presence of uncontrolled eosinophilic inflammation either at local or systemic level was associated with intermediate levels of FeNO. The group of asthmatics showing no increase in eosinophilic inflammation had the lowest level of FeNO. Data are presented as mean±sem.
- Figure 4–
Correlation between Asthma Control Questionnaire (ACQ) score and a) sputum and b) blood eosinophil count when combining the prospective and retrospective cohorts (n=758). Asthma is considered uncontrolled if the ACQ score is >1.5.
Tables
- Table 1– Demographic, control and treatment characteristics for the whole population
Characteristics Retrospective cohort Prospective cohort Subjects n 508 250 Males/females n 201/307 99/151 Age years 52 (19–88) 50 (16–85) Age of onset <12 years 24 22 12–40 years 37 36 ≥40 years 39 42 Height cm 167±9 168±9 Weight kg 74±16 73±17 Atopy yes/no (%) 296/212 (58) 148/102 (59) Current smokers 101 (20) 55 (22) Exposure pack-years 22 (0.5–60) 25 (2–60) Ex-smokers 99 (19) 38 (15) Exposure pack-years 15 (0.5–90) 17 (0.5–63) Bronchiectasis 19ƒ 17 Gastro-oesophageal reflux 79 71* Nasal polyposis 22## 27 Sinusitis 42## 41 Rhinitis 58 56 Exacerbations per patient per year# 0.68±1.50¶¶ 0.86±2.02++ LABA 319 (63) 141 (56) LTRA 93 (18) 50 (20) Theophylline 16 (3) 11 (4) ICS Steroid naïve 153 (30) 82 (33) Low dose¶ 73 (14) 35 (14) Moderate dose+ 138 (27) 63 (25) High dose§ 144 (28) 70 (28) Oral corticosteroids 32 (6) 25 (10) Data are presented as median (range), %, mean±sd or n (%), unless otherwise stated. Exacerbations were evaluated during the year prior to the visit. LABA: long-acting β2-agonist; LTRA: leukotriene receptor antagonist; ICS: Inhaled corticosteroids. High dose: >1000 μg·day−1 beclomethasone. #: during the year prior to the visit; ¶: ≤500 μg per day beclomethasone; +: 500–1000 μg per day beclomethasone; §: >1000 μg per day beclomethasone; ƒ: n=174; ##: n=273; ¶¶: n=428; ++: n=237. *: p<0.05.
- Table 2– Functional and inflammatory characteristics for the whole population
Characteristics Retrospective cohort Prospective cohort FEV1 % predicted 84±19 82±21 FEV1/FVC % 73±11 71±15* PC20 mg·mL−1 geometric mean (range) 3.20 (0.025–16) 2.92 (0.05–16) Reversibility % 11±14 9±10 ACQ score 2.01±1.38 2.00±1.25 AQLQ score 4.61±1.35 4.46±1.39 Blood eosinophil count cells per mm3 230 (0–3220) 188 (0–1133)* FeNO ppb 27 (0–247) 25 (4–348) Sputum eosinophils % 2 (0–94) 2.8 (0–90) Sputum neutrophils % 45 (0–100) 49 (0–100) Data are presented as mean±sd or median (range), unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; PC20: provocative concentration of methacholine causing a 20% fall in FEV1; ACQ: Asthma Control Questionnaire; AQLQ: Asthma Quality of Life Questionnaire; FeNO: exhaled nitric oxide fraction. *: p<0.05.
- Table 3– Retrospective cohort: demographic and treatment characteristics of asthmatics (n=508) according to blood and sputum eosinophil count
Blood eosinophils <400 cells per mm3, sputum eosinophils <3%# Blood eosinophils <400 cells per mm3, sputum eosinophils ≥3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils <3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils ≥3% Subjects 249 (49) 128 (25) 34 (7) 97 (19) Males/females n 78/171 54/74* 16/18 53/44*** Age years 52 (21–86) 53 (21–88) 51 (21–85) 51 (19–86) Age of onset <12 years 22.6 27.6 26.5 23.3 12–40 years 34.5 36.2 32.3 45.6 ≥40 years 42.9 36.2 41.2 31.1 Height cm 166±9 168±9 169±9 169±9 Weight kg 73±16 74±15 76±17 75±17 BMI kg·m−2 26.3±5 26.4±5 26.3±4.8 26.4±5.3 Atopy yes/no (%) 126/123 (51) 82/46 (64)* 22/12 (65) 66/31 (68)** Current smokers 54 (22) 29 (23) 6 (18) 12 (12)* Bronchiectasis¶,+ 19 13 17 26 Gastro-oesophageal reflux 77 81 86 77 Nasal polyposis§ 9 25*** 37*** 43*** Sinusitis§,ƒ 34 38 42 61*** Rhinitis 53 59 72 65 Exacerbations per patient per year## 0.42±0.9 0.93±2.72* 0.59±0.98 1.5±2.5*** ICS Steroid naïve 82 (33) 31 (24) 9 (26) 31 (32) Low dose¶¶ 30 (12) 20 (16) 5 (15) 18 (19) Moderate++ 70 (28) 37 (29) 11 (32) 20 (21) High dose§§ 67 (27) 40 (31)* 9 (26) 28 (29) Data are presented as n (%), median (range), % or mean±sd, unless otherwise stated. BMI: body mass index; ICS: inhaled corticosteroids. #: comparator group; ¶: n=174; +: based on chest computed tomography (CT); §: based on sinus CT and nasal endoscopy; ƒ: n=273; ##: during the year prior to the visit; ¶¶: ≤500 μg per day beclomethasone; ++: 500–1000 μg per day beclomethasone; §§: >1000 μg per day beclomethasone. *: p<0.05; **: p<0.01; ***: p<0.001.
- Table 4– Retrospective cohort: functional characteristics, asthma control and quality of life of asthmatics (n=508) according to blood and sputum eosinophil count
Blood eosinophils <400 cells per mm3, sputum eosinophils <3%# Blood eosinophils <400 cells per mm3, sputum eosinophils ≥3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils <3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils ≥3% FEV1 % predicted 87±19 83±20* 84±23 75±19*** FEV1/FVC % 75±10 72±9* 77±10 71±10*** TLC % predicted 101±16 101±20 92±21 103±15 FRC % predicted 109±29 108±20 97±30 101±18 KCO % predicted 89±19 92±20 99±14** 94±26* PC20 mg·mL−1 geometric mean (range) 3.99 (0.05–16) 2.32 (0.025–16)* 4.53 (0.05–16) 1.49 (0.05–16)** Reversibility % 8±9 13±14* 9±12 17±16*** ACQ score 1.88±1.39 1.87±1.19 1.98±1.5 2.54±1.45*** <0.75 58 (23) 26 (20) 7 (21) 10 (10)** 0.75–1.5 45 (18) 30 (23) 10 (29) 15 (15) >1.5 146 (59) 72 (56) 17 (50) 72 (74)* AQLQ score 4.67±1.36 4.84±1.3 4.47±1.26 4.3±1.4* Data are presented as mean±sd or n (%), unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; TLC: total lung capacity; FRC: functional residual capacity; KCO: transfer coefficient of the lung for carbon monoxide; PC20: provocative concentration of methacholine causing a 20% fall in FEV1; ACQ: Asthma Control Questionnaire; AQLQ: Asthma Quality of Life Questionnaire. #: comparator group. *: p<0.05; **: p<0.01; ***: p<0.001.
- Table 5– Retrospective cohort: inflammatory characteristics of asthmatics (n=508) according to blood and sputum eosinophil count
Blood eosinophils <400 cells per mm3, sputum eosinophils <3%# Blood eosinophils <400 cells per mm3, sputum eosinophils ≥3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils <3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils ≥3% IgE kU·L−1 87 (1–7338) 211 (3–6785)*** 180 (13–2329)* 225 (1–17183)*** Blood eosinophils % 1.7 (0–5.4) 3.2 (0–7)*** 6 (0.3–15)*** 8 (0.4–30)*** Blood eosinophils per mm3 140 (0–380) 250 (0–390)*** 490 (400–1220)*** 590 (400–3220)*** Blood neutrophils % 59 (27–82) 57 (34–91) 57 (41–76) 52 (32–67)*** Blood neutrophils per mm3 4180 (76–11 080) 4370 (2290–15 410) 5040 (1760–10 010) 3965 (1820–8670) Sputum eosinophils % 0.3 (0–2.9) 9 (3–79)*** 0.6 (0–2.8) 26 (3.2–94)*** Sputum eosinophils per mm3 2.7 (0–1020) 70 (6–5226)*** 4.8 (0–1796) 287 (5–33 375)*** Sputum neutrophils % 58 (0–100) 39 (0–90)*** 57 (0.2–99) 30 (0.2–91)*** Sputum neutrophils per mm3 422 (0–73 440) 334 (1–9588) 560 (14–160 974) 259 (1–15 441) Fibrinogen g·L−1 3.2 (1.9–10) 3 (2–6) 3.3 (2.6–5) 3.4 (2.2–7) CRP mg·L−1 1.7 (0.2–10) 2 (0.2–14) 1.4 (0.5–4) 1.6 (0.2–13) FeNO ppb 17 (0–192) 37 (2–222)*** 32 (5–93)** 77 (11–247)*** Data are presented as median (range). CRP: C-reactive protein; FeNO: exhaled nitric oxide. #: comparator group. *: p<0.05; **: p<0.01; ***: p<0.001.
- Table 6– Retrospective cohort: demographic, functional and inflammatory characteristics of patients receiving high doses of corticosteroids (n=144)
Blood eosinophils <400 cells per mm3, sputum eosinophils <3%# Blood eosinophils <400 cells per mm3, sputum eosinophils ≥3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils <3% Blood eosinophils ≥400 cells per mm3, sputum eosinophils ≥3% Subject n (%) 67 (47) 40 (28) 9 (6) 28 (19) Males/females n 20/47 16/24 5/4 15/13 Age years 52 (21–86) 59 (26–88) 62 (44–85) 52 (29–86) Age of onset % <12 years 25 35 0 30 12–40 years 33 30 50 40 ≥40 years 42 35 50 30 Exacerbations per patient per year¶ 0.76±1.06 0.95±1.29 1.25±1.17 3.52±5.00*** FEV1 % predicted 77±17 77±20 71±28 65±18** FEV1/FVC % 73±11 68±13 70±11 64±9** ACQ score 2.57±1.96 1.97±1.25 3.19±1.79 3.18±1.38 AQLQ score 4.11±1.39 4.52±1.40 3.59±1.47 3.50±1.31 FeNO ppb 14 (4–114) 30 (8–119)*** 10 (5–58) 55 (11–139)*** Blood eosinophils per mm3 160 (10–350) 225 (0–390)*** 465 (400–1030)*** 615 (400–3220)*** Sputum eosinophils % 0.25 (0–2.6) 8.4 (3–52.2)*** 0.4 (0–2.7) 22.3 (3.6–94.4)*** Data are presented as median (range) or mean±sd, unless otherwise stated. FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; ACQ: Asthma Control Questionnaire; AQLQ: Asthma Quality of Life Questionnaire; FeNO: exhaled nitric oxide fraction. #: comparator group; ¶: during the year prior to the visit. *: p<0.05; **: p<0.01; ***: p<0.001.
Supplementary material
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Files in this Data Supplement:
- Prospective cohort - Asthma control and exacerbation rate in asthmatics classified according to blood and sputum eosinophil count
ERJ Podcast
Duration: 15:45 min
Presenter: Marc Humbert, Chief Editor, ERJ
Interviewee: Renaud Louis, Dept of Pulmonary Medicine, CHU Sart-Tilman, Liege, I3GIGA Research Group, University of Liege, Liege, Belgium
Articles discussed:
- Kostikas K, Zervas E, Gaga M. Airway and systemic eosinophilia in asthma: does site matter? Eur Respir J 2014; 44: 14-16. Full Text
- Schleich FN, Chevremont A, Paulus V, et al. Importance of concomitant local and systemic eosinophilia in uncontrolled asthma. Eur Respir J 2014; 44: 97-108. Full Text
- Ortega H, Chupp G, Bardin P, et al. The role of mepolizumab in atopic and nonatopic severe asthma with persistent eosinophilia. Eur Respir J 2014; 44: 239-241. Full Text
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Files in this Data Supplement:
- Listen to podcast - July 2014
