Serum Eosinophil Cationic Protein for Predicting the Prognosis of a Step-Down in Inhaled Corticosteroid Therapy in Adult Chronic Asthmatics

Abstract

We investigated whether the serum concentration of eosinophil cationic protein (s-ECP) can be used to determine when a step-down in inhaled corticosteroid therapy is indicated for patients with chronic asthma. A total of 24 adult patients, whose symptoms were well controlled with inhaled beclomethasone dipropionate (iBDP), were studied. The dosage of iBDP was reduced by half once a month until the dose reached one-quarter of the original level. s-ECP and blood eosinophil counts were determined once a month before and during the 6-month period after the step-down. In 12 patients, moderate and frequent exacerbation occurred, thus requiring a return to the initial or twice the initial dose of iBDP. Thus, the step-down here was defined as unsuccessful. In the remaining 12 patients, the symptoms were stable over the course of the 6 months, and the step-down was defined as successful. s-ECP correlated with eosinophil counts in peripheral blood (EOS) in both the successful and the unsuccessful groups. Although EOS before the step-down did not differ significantly between the two groups, s-ECP was significantly higher in the unsuccessful group (mean 35.7 microg/L) than in the successful group (mean 17.0 microg/L, p < 0.03). Thus, s-ECP appears to be a useful marker for determining when a step-down in iBDP therapy is indicated, and thus may contribute to successful long-term management of chronic asthma.

Long‐term observations of the clinical course after step down of corticosteroid inhalation therapy in adult chronic asthmatics: Correlation with serum levels of eosinophil cationic protein

“…The rate of exacerbation within 3 months of the initial step down was higher in group B patients (45.5%) than in group A patients (23.1%), although the difference was not statistically significant. We have reported previously that a high level of sECP may indicate an increased risk of exacerbation within a short‐term clinical course after a step down in iBDP therapy 6 . The results in the present study confirm these previous findings.…”

“…Several lines of evidence indicate that theophylline contributes to asthma control by affecting eosinophil‐relevant airway inflammation 14–17 . We examined the short‐term prognosis of a step down in iBDP therapy among patients taking oral theophylline and found that sECP still rose following the step down 6 . Furthermore, we reported that sECP levels in asthmatics did not change significantly after withdrawal of theophylline 18 .…”

“…Our previous studies 6,7 raised the following questions: (i) what is the long‐term prognosis after step down in iBDP therapy in patients who are stable but whose sECP levels are high (i.e. the step down risk is considered to be high); (ii) what is the long‐term prognosis in patients whose sECP levels are low; and (iii) what is the long‐term prognosis of patients for whom the step down risk is expected to be high and are therefore administered an LT or TxA 2 receptor antagonist?…”

Effects Of Theophylline Withdrawal in Well-Controlled Asthmatics Treated with Inhaled Corticosteroid

“…This finding is in contrast to our previous finding that sECP before a step down in iBDP therapy was significantly higher in patients when the step down was successful than when it was unsuccessful (6,7). Furthermore, the finding in the present study that significant fluctuation in EOS or sECP was not observed even during symptom deterioration also differed from the results obtained in our previous study (7).…”

“…However, the mechanisms of these actions remain unclear, unlike corticosteroid, which is known to be only an anti-inflammatory agent. We previously performed long-term consecu- tive measurement of the serum concentration of eosinophil cationic protein (sECP) in adult asthmatics, and reported that in mild to moderately persistent asthmatics whose symptoms were well controlled by 400-800 mg inhaled beclomethasone dipropionate (iBDP)/day, sECP is a useful indicator of the requirement for a step down in iBDP therapy (6)(7)(8).…”