This is the first report to our knowledge showing the feasibility of assessing synthetic glucocorticoids in induced sputum of an asthmatic patient to document current compliance to therapy. The patient was shown to be compliant with his medication regimen at the time of sample analysis. Corresponding evidence of adherence included a reduction in symptoms, improvement in spirometry, and a decrease in sputum eosinophilia from 78 to 2%. Although before this episode of care the patient's clinical course had been refractory to both inhaled and oral corticosteroids, suggesting possible steroid resistance, with documented compliant administration of treatment he was shown to improve clinically, confirmed by reductions in airflow obstruction and sputum eosinophils.10
Use of sputum induction in the evaluation and treatment of asthma has been shown to be safe and reproducible.11,12
Greene et al.
suggest that treatment of eosinophilic inflammation detected through induced sputum would lead to better control of moderate to severe asthma.7
This suggestion has been supported by meta-analysis in adults.13
Also, several published studies show that induced sputum reveals information qualitatively similar to bronchoscopy and bronchial washings.9
Thus, through sputum induction we can measure airway inflammation, adherence with therapy, and, by repeat testing, response to treatment.14
Milgrom et al.
showed that patient-reported use of their inhaled corticosteroids in diaries was 95.4% whereas their median actual use was 58.4%. The majority of the patients (90%) in that study exaggerated their adherence with inhaled steroids. Furthermore, children who required a steroid burst for an exacerbation had much lower rates of adherence (14%) than those who did not experience exacerbations (68%).5
Guilbert's thoughtful analysis of the long-term effects of inhaled corticosteroids in children was limited by a 25–30% nonadherence rate.15
Rates of nonadherence with asthma therapy have been reported as 20% to 80%.2
The consequences of poor adherence with asthma include absences from work or school, increased emergency room visits, more severe attacks, increased drug side effects, greater cost of care, and death.16
According to the National Asthma Education and Prevention Program Expert Panel Report 3 Guidelines, adherence to medications should be assessed before “stepping up” asthma care. Referral to an asthma specialist should be considered if there are concerns over poor adherence. However, specific tools to document nonadherence are not outlined for either the primary or the specialty physician in these guidelines.17
Inhaled corticosteroids are currently the most effective long-term control medications for asthma and, fortunately, provide control for the majority of asthmatic patients.6
Appropriate use and avoidance of systemic corticosteroid overuse is essential to providing optimal asthma care. Regular use of inhaled corticosteroids is associated with a decreased risk of death from asthma.18
Because we rely on these drugs for the majority of patients with asthma and the ability of clinicians to determine adherence is not perfect, a gold standard for assessing adherence could provide useful information in select patients. In addition, direct analysis of glucocorticoids in sputum could provide a tool to augment the reliability of sputum eosinophil assessments. We report the first case to our knowledge where sputum as well as blood and urine were used to determine adherence with therapy.
This is the first report to our knowledge where direct measurements of synthetic glucocorticoids were performed in asthmatic sputum to assess current compliance to inhaled therapy. This novel method to assess inhaled steroids in sputum has potential value such as documenting current compliance to inhaled steroids when considering “step up care” or improving the interpretation of sputum eosinophilia in a specific patient. This methodology could be particularly important in differentiating poor adherence from steroid resistance in a specific patient. Concomitant measurements of airway inflammation, adherence with therapy, and response to treatment may have applicability in a tertiary referral center for asthma.