Serum eosinophil cationic protein for predicting the prognosis of a step-down in inhaled corticosteroid therapy in adult chronic asthmatics

Stepping down the dose of inhaled corticosteroids for adults with asthma

BACKGROUND

Asthma is a condition of the airways affecting more than 300 million adults and children worldwide. National and international guidelines recommend titrating up the dose of inhaled corticosteroids (ICS) to gain symptom control at the lowest possible dose because long-term use of higher doses of ICS carries a risk of systemic adverse events. For patients whose asthma symptoms are controlled on moderate or higher doses of ICS, it may be possible to reduce the dose of ICS without compromising symptom control.

OBJECTIVES

To evaluate the evidence for stepping down ICS treatment in adults with well-controlled asthma who are already receiving a moderate or high dose of ICS.

SEARCH METHODS

We identified trials from the Specialised Register of the Cochrane Airways Group and conducted a search of ClinicalTrials.gov (www.ClinicalTrials.gov) and the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/). We searched all databases from their inception with no restriction on language. We also searched the reference lists of included studies and relevant reviews. We performed the most recent search in July 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least 12 weeks' duration and excluded cross-over trials. We looked for studies of adults (aged ≥ 18 years) whose asthma had been well controlled for a minimum of three months on at least a moderate dose of ICS. We excluded studies that enrolled participants with any other respiratory comorbidity.We included trials comparing a reduction in the dose of ICS versus no change in the dose of ICS in people with well-controlled asthma who a) were not taking a concomitant long-acting beta agonist (LABA; comparison 1), and b) were taking a concomitant LABA (comparison 2).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included studies, extracted data on prespecified outcomes of interest and assessed the risk of bias of included studies; we resolved disagreements by discussion with a third review author. We analysed dichotomous data as odds ratios (ORs) using study participants as the unit of analysis and analysed continuous data as mean differences (MDs). We used a random-effects model. We rated all outcomes using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) system and presented results in 'Summary of findings' tables.

MAIN RESULTS

We included six studies, which randomised a total of 1654 participants (ICS dose reduction, no concomitant LABA (comparison 1): n = 892 participants, three RCTs; ICS dose reduction, concomitant LABA (comparison 2): n = 762 participants, three RCTs). All included studies were RCTs with a parallel design that compared a fixed dose of ICS versus a 50% to 60% reduction in the dose of ICS in adult participants with well-controlled asthma. The duration of the treatment period ranged from 12 to 52 weeks (mean duration 21 weeks; median duration 14 weeks). Two studies were performed in the setting of primary care, two were performed in the secondary care setting and two reported no information on setting.Meta-analysis was hampered by the small number of studies contributing to each comparison, combined with heterogeneity among outcomes reported in the included studies. We found the quality of synthesised evidence to be low or very low for most outcomes considered because of a risk of bias (principally, selective reporting), imprecision and indirectness. Although we found no statistically significant or clinically relevant differences between groups with respect to any of the primary or secondary outcomes considered in this review, the data were insufficient to rule out benefit or harm.

AUTHORS' CONCLUSIONS

The strength of the evidence is not sufficient to determine whether stepping down the dose of ICS is of net benefit (in terms of fewer adverse effects) or harm (in terms of reduced effectiveness of treatment) for adult patients with well-controlled asthma. A small number of relevant studies and varied outcome measures limited the number of meta-analyses that we could perform. Additional well-designed RCTs of longer duration are needed to inform clinical practice regarding use of a 'stepping down ICS' strategy for patients with well-controlled asthma.

Randomized comparison of strategies for reducing treatment in mild persistent asthma

BACKGROUND

Treatment guidelines recommend the use of inhaled corticosteroids in patients with asthma who have persistent symptoms and the "stepping down" of therapy to the minimum needed to maintain control of asthma. Whether patients with asthma that is well controlled with the use of inhaled corticosteroids twice daily can receive a step-down treatment with once-daily montelukast (our primary hypothesis) or once-daily fluticasone propionate plus salmeterol (our secondary hypothesis) has not yet been determined.

METHODS

We randomly assigned 500 patients with asthma that was well controlled by inhaled fluticasone (100 microg twice daily) to receive continued fluticasone (100 microg twice daily) (169 patients), montelukast (5 or 10 mg each night) (166 patients), or fluticasone (100 microg) plus salmeterol (50 microg) each night (165 patients). Treatment was administered for 16 weeks in a double-blind manner. The primary outcome was the time to treatment failure.

RESULTS

Approximately 20% of patients assigned to receive continued fluticasone or switched to treatment with fluticasone plus salmeterol had treatment failure, as compared with 30.3% of subjects switched to montelukast. The hazard ratio for both comparisons was 1.6 (95% confidence interval, 1.1 to 2.6; P=0.03). The percentage of days on which patients were free of asthma symptoms (78.7 to 85.8%) was similar across the three groups.

CONCLUSIONS

Patients with asthma that is well controlled with the use of twice-daily inhaled fluticasone can be switched to once-daily fluticasone plus salmeterol without increased rates of treatment failure. A switch to montelukast results in an increased rate of treatment failure and decreased asthma control; however, patients taking montelukast remained free of symptoms on 78.7% of treatment days. (ClinicalTrials.gov number, NCT00156819 [ClinicalTrials.gov].).

Biomarkers predicting response to corticosteroid therapy in asthma

International guidelines on the management of asthma support the early introduction of corticosteroids to control symptoms and to improve lung function by reducing airway inflammation. However, not all individuals respond to corticosteroids to the same extent and it would be an advantage to be able to predict the response to corticosteroid treatment. Several biomarkers have been assessed following treatment with corticosteroids including measures of lung function, peripheral blood and sputum indices of inflammation, exhaled gases and breath condensates. The most widely examined measures in predicting a response to corticosteroids are airway hyperresponsiveness, exhaled nitric oxide (eNO) and induced sputum. Of these, sputum eosinophilia has been demonstrated to be the best predictor of a short-term response to corticosteroids. More importantly, directing treatment at normalizing the sputum eosinophil count can substantially reduce severe exacerbations. The widespread utilization of sputum induction is hampered because the procedure is relatively labor intensive. The measurement of eNO is simpler, but incorporating the assessment of NO in an asthma management strategy has not led to a reduction in exacerbation rates. The challenge now is to either simplify the measurement of a sputum eosinophilia or to identify another inflammatory marker with a similar efficacy as the sputum eosinophil count in predicting both the short- and long-term responses to corticosteroids.

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

BACKGROUND

Symptoms often deteriorate in well-controlled asthmatics after a step down in inhaled beclomethasone dipropionate (iBDP) therapy if the serum concentration of eosinophil cationic protein (sECP) is high. This deterioration is significantly abrogated by pranlukast, a leukotriene receptor antagonist, or by seratrodast, a thromboxane A2 receptor antagonist. However, these results were based on short-term (less than 6 months) observations.

METHODS

We studied 35 well-controlled adult asthmatics. We assigned the patients into different groups according to their sECP levels before the step down: (i) group A, sECP < 25 microg/L; (ii) group B, sECP > or = 25 microg/L; and (iii) group C, sECP > or = 25 microg/L but patients treated with pranlukast or seratrodast. We began the study with a step down in iBDP therapy (initial step down), then followed the clinical course of the asthma for 2 years. During the study period, we decreased, increased or maintained the iBDP dose on the basis of the stepwise approach described in the National Institutes of Health guidelines. We monitored the time and frequency of exacerbation and evaluated the iBDP dose required to control the asthma symptoms.

RESULTS

The rates of exacerbation after the step down were high in groups A and B. In group A, the conditions were again qualified for the step down in all patients, but this was not the case for most group B patients. From 15 to 21 months after the initial step down, the average dose of iBDP required to control symptoms was significantly higher in group B than in group A patients (P = 0.0127-0.0373). The exacerbation rate in group C after 12 months tended to be lower than in the other two patient groups (P = 0.0743). In group C, the average dose of iBDP from 9 to 24 months after the initial step down was significantly lower than before the step down (P < 0.0001) and was not significantly different from the mean dose of iBDP in groups A or B.

CONCLUSIONS

High sECP in well-controlled asthma may indicate the necessity for a higher iBDP dose over a long period than when the sECP concentration is not high. Even if sECP is high, pranlukast or seratrodast help to prevent exacerbation of asthma and enable successful step down in iBDP therapy for at least 2 years thereafter.

Effects of theophylline withdrawal in well-controlled asthmatics treated with inhaled corticosteroid

We examined effects of theophylline withdrawal in 17 adult asthmatics whose symptoms were well controlled under a treatment of a combination of theophylline and inhaled beclomethasone dipropionate (iBDP). We measured daily symptoms, daily peak flow values, spirometry, peripheral blood eosinophil count (EOS), and serum eosinophil cationic protein (sECP) at intervals of 1-3 weeks for 3 months after theophylline withdrawal. Twelve patients experienced exacerbation of asthma (exacerbation group), whereas the remaining 5 patients exhibited no symptoms (stationary group). In the exacerbation group, forced expiratory volume in 1 sec (FEV1) and percent vital capacity (% VC) gradually decreased until exacerbation of asthma, and the extent of these decreases within the first week after the withdrawal was greater compared with that at later than the third week. V25/HT decreased in both the exacerbation and stationary groups. In particular, the extent of the velocity of expiratory flow at 25% of the vital capacity/height (V25/HT) decrease in the exacerbation group was much greater than that of FEV1 or % VC in this group. Neither EOS nor sECP changed significantly during the clinical course in any patient. The rapid decrease in FEV1 and % VC after the withdrawal suggests that under treatment with iBDP, theophylline causes direct bronchodilating effects on smooth muscle, rather than anti-inflammatory effects. These results also suggest the importance of theophylline on peripheral as well as central airways.