An inhaled steroid improves markers of airway inflammation in patients with mild asthma.
Airway inflammation can be demonstrated in mildly asthmatic patients who are not treated with inhaled steroids. Current guidelines recommend that inhaled steroids should be introduced in mild asthmatics who use an inhaled beta2-agonist more than once daily. It was postulated that inhaled steroids can have anti-inflammatory effects in patients with even milder disease. The effect of 4 weeks of treatment with budesonide (800 microg twice daily by Turbohaler) was studied in 10 steroid-naive mildly asthmatic patients (forced expiratory volume in one second (FEV1) = 96+/-1.4% predicted) who required an inhaled beta2-agonist less than one puff daily, in a double-blind, placebo-controlled, crossover fashion. Spirometry, exhaled nitric oxide (NO), bronchial responsiveness (provocative concentration causing a 20% fall in FEV1 (PC20)), and sputum induction were performed before and after each treatment period. Following budesonide treatment, there were significant improvements in FEV1, and PC20, in association with a significant reduction in the percentage of eosinophils in induced sputum. Exhaled NO levels tended towards reduction, but the change was nonsignificant. There were also nonsignificant reductions in sputum eosinophil cationic protein and tumour necrosis factor-alpha levels. In conclusion inhaled budesonide can lead to improvements in noninvasive markers of airway inflammation, in association with a small improvement in lung function, even in mildly asthmatic patients who require an inhaled beta2-agonist less than once daily. This suggests a potential benefit of inhaled corticosteroids, even in relatively asymptomatic asthma.
Currently there is a clear lack of evidence to support the use of azathioprine in the treatment of chronic asthma as a steroid sparing-agent. Large, long-term studies with pre-defined steroid reducing protocols are required before recommendations for clinical practice can be made.