Low variability in peak expiratory flow predicts successful inhaled corticosteroid reduction in adults

Published online: December 6, 2017

Current guidelines from the Global Initiative for Asthma recommend that when control in adult patients with asthma is maintained for at least 3 months, treatment can be stepped down to minimize the cost and maximize the safety of the treatment. However, previous studies have monitored clinical outcomes for only 1 to 6 months after inhaled corticosteroids (ICS) dose reduction, and the prognosis for patients beyond 1 year after ICS reduction remains unknown. In fact, some reports indicate that reducing the ICS dose leads to deterioration of asthma control in adult patients. Moreover, factors that can be evaluated before the initiation of any asthma treatment or at the time of ICS reduction and that are predictive of long-term control are unknown.

In a recently published research article in The Journal of Allergy and Clinical Immunology; In Practice, Tsurikisawa and colleagues investigated predictive factors of long-term disease control that can be evaluated before the initiation of asthma treatment or at the time of consideration of dose reduction of inhaled corticosteroids. Two hundred twenty-three patients enrolled in six hospitals in the National Hospital Organization of Japan during the 36 months after 50% reduction of their daily ICS dose were studied. All patients recorded their morning and evening peak expiratory flows (PEFs) in their diaries. Lung function, bronchial hyperresponsiveness, fractional exhaled nitric oxide (FeNO) levels, numbers of eosinophils in sputum, and serum IgE levels were measured in most patients. Serum levels of interleukin (IL)-10, IL-33, and thymic stromal lymphopoietin before ICS reduction were measured in all patients.

The authors found during the 36-month study period, asthma control was retained in 127 (59.6%) of the 213 enrolled patients who underwent ICS dose reduction. Multivariate logistic regression analysis revealed that, at the initiation of dose reduction, the factors most predictive of maintenance of asthma control after ICS reduction were a low serum IL-33 level, low PEF variability over 1 week, childhood onset of asthma (at <10 years of age), and low serum IL-10 level.

These findings suggest that low PEF variability over 1 week, low serum IL-10 level, and low serum IL-33 concentration were useful factors for predicting that an adult asthmatic will remain in control for months to years after a 50% reduction in their daily ICS dose.

The Journal of Allergy and Clinical Immunology; In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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