Pulmonary · COPD · Clinical Pearl
Blood eosinophils can help decide when inhaled corticosteroids are worth the risk
Lede: In COPD, blood eosinophils are not a stand-alone indication for inhaled corticosteroids, but they can help estimate how likely a patient with exacerbations is to benefit from adding ICS.
Why it matters
The benefit of inhaled corticosteroids in COPD is greatest when the patient has a meaningful exacerbation history and an eosinophilic inflammatory signal. Current GOLD guidance treats the eosinophil count as a continuum of predicted ICS response, not a binary cutoff. Benefit is generally small at very low counts, becomes more likely above about 100 cells/µL, and is greatest around 300 cells/µL or higher—especially in patients who continue to exacerbate despite long-acting bronchodilator therapy.
The pearl
Use blood eosinophils to modify the expected benefit of ICS—not to prescribe ICS automatically.
- <100 cells/µL: expected preventive benefit from ICS is usually low.
- 100–299 cells/µL: potential benefit rises progressively and should be interpreted alongside exacerbation history.
- ≥300 cells/µL: the probability of exacerbation reduction with ICS is highest, and withdrawal may increase exacerbation risk in susceptible patients.
The other side of the decision is risk. ICS can increase pneumonia risk in COPD, so the clinical question is not simply “Is the eosinophil count high?” but rather: Does this patient’s exacerbation risk and inflammatory phenotype justify the added corticosteroid exposure?
Go deeper
- GOLD 2026 Report — blood eosinophils and ICS treatment in COPD
- Pascoe S, et al. Blood eosinophil counts, exacerbations, and response to inhaled fluticasone furoate in COPD. Lancet Respir Med. 2015.
- Watz H, et al. Blood eosinophils and exacerbations after withdrawal of inhaled corticosteroids: WISDOM analysis. Lancet Respir Med. 2016.
Educational content for clinicians and trainees. This material does not replace individualized clinical judgment or patient-specific medical care.
