TABLE 1.
Characterization of eosinophilic and non‐eosinophilic phenotypes of difficult asthma in the WATCH cohort using ISAR eosinophil gradient algorithm
|
Highest BEC Cells/µl |
Treatment or clinical characteristics | Eosinophilic phenotype | ISAR study |
WATCH (latest result test only) |
WATCH (highest result in last 5 years) |
WATCH (highest result in last 10 years) |
WATCH (highest result ever) |
||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||
| ≥300 | n/a |
Grade 3 Most likely |
83.8% | 163 (32.6%) | 225 (45.0%) | 296 (59.2%) | 335 (67.0%) | 342 (68.4%) | 374 (74.8%) | 359 (71.8%) | 387 (77.4%) |
| n/a | On anti‐IL−5 or anti‐IL−5Rα therapy |
Grade 3 Most likely |
39 (7.8%) | 15 (3.0%) | 10 (2.0%) | 8 (1.6%) | |||||
| 150–300 | Long‐term OCS |
Grade 3 Most likely |
15 (3.0%) | 19 (3.8%) | 18 (3.6%) | 17 (3.4%) | |||||
| Presence of >2 of the following NP, FeNO >25 ppb or adult onset (no long‐term OCS) |
Grade 3 Most likely |
8 (1.6%) | 5 (1.0%) | 4 (0.8%) | 3 (0.6%) | ||||||
| Either NP, elevated FeNO or adult onset (no long‐term OCS) |
Grade 2 Likely |
3.9% | 28 (5.6%) | 29 (5.8%) | 29 (5.8%) | 25 (5.0%) | |||||
| No NP, elevated FeNO, adult onset or long‐term OCS |
Grade 1 Least likely |
1.6% | 28 (5.6%) | 27 (5.4%) | 29 (5.8%) | 25 (5.0%) | |||||
| <150 | Long‐term OCS | Grade 2 | 4.4% | 71 (14.2%) | 33 (6.6%) | 22 (4.4%) | 20 (4.0%) | ||||
| Either NP, FeNO >25 ppb or adult onset (no long‐term OCS) |
Grade 1 Least likely |
4.7% | 82 (16.4%) | 39 (7.8%) | 25 (5.0%) | 22 (4.4%) | |||||
| No NP, elevated FeNO, adult‐onset or long‐term OCS |
Grade 0 Unlikely (non) |
1.6% | 66 (13.2%) | 37 (7.4%) | 21 (4.2%) | 21 (4.2%) | |||||
Table replicated from the ISAR phenotypes Heaney 2021 5 compared to the WATCH data.
FeNO, NP and mOCS were current at the time of enrolment.
Abbreviations: BEC, Blood eosinophil counts; FeNO, fraction of exhaled nitric oxide; IL‐5, interleukin 5’; ISAR, International Severe Asthma Registry; n/a, not applicable; NP, nasal polyps; OCS, oral corticosteroids; ppb, parts per billion; WATCH, Wessex AsThma CoHort of difficult asthma.