Addressing Asthma Exacerbations Via Sputum Eosinophils vs Clinical Symptoms

eosinophil ganulocytes
eosinophil ganulocytes
Adults with asthma benefit from tailoring interventions based on sputum eosinophils vs clinical symptoms.

Modifying interventions based on sputum eosinophils is beneficial for reducing the frequency of exacerbations in adults with asthma, according to a recent review published in the Cochrane Database of Systematic Reviews.

As the researchers noted, the severity and control of asthma can be assessed via both subjective and objective measures. One method for the objective assessment of asthma is sputum analysis, which evaluates the percentage of sputum eosinophilia and thus directly measures airway inflammation. The use of sputum analysis for adjusting or tailoring asthma medications may be superior to the use of traditional methods, which are based on patients’ symptoms and spirometry/peak flow.


The investigators searched a variety of databases for relevant randomized controlled comparisons of asthma treatment adjustments based on sputum eosinophils vs traditional methods. A total of 6 studies comprising 382 participants were included in the analysis (5 studies in adults [n=327] and 1 study in children/adolescents [n=55]). Study participants were between aged 12 and 48 years .

A significant reduction in asthma exacerbations was observed when treatment was based on sputum eosinophil counts vs clinical symptoms with or without lung function results (pooled odds ratio, 0.57; 95% CI, 0.38-0.86). The risk of experiencing ≥1 exacerbation during 16 months was 82% in the control arm vs 62% in the sputum arm (number needed to treat to benefit, 6; 95% CI, 4-13).

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Differences were also reported between the 2 groups with respect to the rate and severity of asthma exacerbations, which was determined by of the need for oral corticosteroids and hospitalization. The risk for ≥1 hospitalization during 16 months was 24% in the control group vs 8% in the sputum group (95% CI, 3%-21%). Data on clinical symptoms, quality of life, and spirometry were similar in both groups.

The researchers concluded that tailoring asthma interventions based on sputum eosinophils was helpful in decreasing the occurrence of asthma exacerbations in adults. Insufficient data were available regarding the usefulness of sputum eosinophilia vs clinical symptoms in children with asthma.


Petsky HL, Li A, Chang AB. Tailored interventions based on sputum eosinophils versus clinical symptoms for asthma in children and adults. Cochrane Database Syst Rev.
2017;8:CD005603. doi:10.1002/14651858.CD005603.pub3