Comparison of clinical, treatment, sputum and blood characteristics before and after a cessation/decreased dose of ICS, according to the baseline eosinophilic phenotype
| Eosinophilic asthmatics before a cessation/decreased dose of ICS (N=22) | Eosinophilic asthmatics after a cessation/decreased dose of ICS (N=22) | P value | Non-eosinophilic asthmatics before a cessation/decreased dose of ICS (N=38) | Non-eosinophilic asthmatics after a cessation/decreased dose of ICS (N=38) | P value | |
| ACQ | 2.2±1.5 | 2.4±1.3 | 0.19 | 1.9±1.1 | 1.5±1.1 | 0.026 |
| Mini-AQLQ | 4.4±1.8 | 4.1±1.6 | 0.045 | 4.3±1.3 | 4.9±1.4 | 0.007 |
| Number of severe exacerbations in the previous year* | 0.2±0.1† | 0±0† | 0.16 | 1.2±0.5‡ | 0.3±0.2‡ | 0.027 |
| Prebronchodilator FEV1, % predicted | 75.2±19.2 | 72.3±20.1 | 0.30 | 81.2±16.7 | 81.4±19.5 | 0.93 |
| PC20M, mg/mL | >16 (>16->16)§ | 8.20 (3.35->16)§ | 0.17 | 12.00 (3.42->16)¶ | 3.30 (1.46->16)¶ | 0.19 |
| ICS dose, beclomethasone equivalents | 1800 (1000–2400) | 800 (200–1600) | – | 1100 (800–2000) | 400 (0–1000) | – |
| LABA, n (%) | 19 (86) | 18 (82) | 1.0 | 31 (82) | 24 (63) | 0.039 |
| LTRA, n (%) | 4 (18) | 4 (18) | 1.0 | 14 (37) | 12 (32) | 0.63 |
| Theophylline, n (%) | 0 (0) | 0 (0) | 1.0 | 1 (3) | 1 (3) | 1.0 |
| Antihistamine, n (%) | 4 (18) | 4 (18) | 1.0 | 7 (18) | 12 (32) | 0.13 |
| FENO, ppb | 48 (15–67)** | 46 (25–79)** | 0.59 | 15 (10–34)†† | 16 (10–30)†† | 0.88 |
| Sputum total non-squamous cell count, × 106/g | 1.05 (0.49–1.79) | 2.03 (0.63–3.34) | 0.035 | 1.63 (0.59–4.27) | 1.16 (0.65–2.26) | 0.12 |
| Sputum viability, % | 68 (61–74) | 69 (52–77) | 0.78 | 71 (63–83) | 67 (59–80) | 0.61 |
| Sputum squamous cells, % | 16 (9–23) | 14 (2–25) | 0.26 | 15 (3–36) | 14 (4–29) | 0.97 |
| Sputum eosinophils, × 103/g | 148 (28–328) | 107 (24–480) | 0.52 | 6 (0–18) | 24 (2–120) | 0.002 |
| Sputum eosinophils, % of non-squamous cells | 11.1 (5.4–16.3) | 8.1 (1.0–24.8) | 0.90 | 0.4 (0.0–1.4) | 2.3 (0.2–6.2) | <0.0001 |
| Sputum neutrophils, × 103/g | 408 (107–823) | 364 (239–1522) | 0.062 | 685 (175–3565) | 922 (242–1415) | 0.50 |
| Sputum macrophages, × 103/g | 345 (112–655) | 528 (110–1230) | 0.24 | 368 (148–933) | 197 (114–412) | 0.026 |
| Sputum lymphocytes, × 103/g | 19 (2–59) | 37 (12–94) | 0.031 | 8 (1–50) | 9 (5–39) | 0.71 |
| Sputum epithelial cells, × 103/g | 59 (10–124) | 112 (48–227) | 0.053 | 53 (7–143) | 25 (12–92) | 0.057 |
| Blood leucocytes, × 109/L | 7.47 (6.32–9.37) | 7.86 (6.74–9.49) | 0.64 | 7.95 (6.69–9.56) | 7.18 (5.81–8.87) | 0.057 |
| Blood eosinophils, /µL | 319 (164–452) | 304 (187–456) | 0.83 | 179 (91–306) | 218 (132–441) | 0.032 |
| Blood neutrophils, /µL | 4209 (3666–5303) | 3953 (3526–4927) | 0.71 | 4684 (3500–5774) | 3785 (2882–5606) | 0.007 |
| Blood monocytes, /µL | 452 (354–645) | 517 (381–692) | 0.37 | 498 (407–626) | 526 (452–610) | 0.55 |
| Blood lymphocyte, /µL | 2383 (1979–2624) | 2628 (2288–2957) | 0.37 | 2220 (1729–2600) | 2188 (1948–2914) | 0.49 |
| Blood basophils, /µL | 42 (28–56) | 38 (32–42) | 0.19 | 33 (23–47) | 35 (23–43) | 0.44 |
| CRP, mg/L | 1.8 (1.1–3.7)‡‡ | 1.8 (0.5–3.6)‡‡ | 0.50 | 3.2 (0.9–8.4)§§ | 2.2 (0.8–5.9)§§ | 0.18 |
| Fibrinogen, g/L | 3.3 (3.0–3.5)¶¶ | 3.4 (3.0–3.7)¶¶ | 0.65 | 3.9 (3.3–4.2)*** | 3.5 (3.0–3.8)*** | 0.07 |
*Data are presented as mean±SEM.
Data available for both visits in: †9, ‡10, §3,¶13, **19,††31 ‡‡11, §§21, ¶¶10, and ***18 patients.
ACQ, Asthma Control Questionnaire; AQLQ, Asthma Quality of Life Questionnaire; CRP, C reactive protein; FENO, fractional exhaled nitric oxide; FEV1, forced expiratory volume in 1 s; ICS, inhaled corticosteroid; LABA, long-acting β2 agonist; LTRA, leukotriene receptor antagonist; PC20M, provocative concentration of methacholine causing a 20% fall in FEV1; ppb, parts per billion.