Salt chamber treatment is ineffective in treating eosinophilic inflammation in asthma

BACKGROUND: We have shown that salt chamber treatment reduces airway hyper-responsiveness as an add-on therapy in adult asthmatics on inhaled corticosteroids. METHODS: We assessed whether this effect is due to the suppression of eosinophilic airway inflammation. Thirty-nine adult asthmatics on inhaled corticosteroids were randomized to receive active salt chamber treatment with low-salt treatment 6.6 mg/m(3) (n = 14), high-salt treatment 10.8 mg/m(3) (n = 15) or placebo 0.3 mg/m(3) (n = 10) 10 times in a 2 weeks' period in a double-blind manner. RESULTS: The level of induced sputum eosinophilic cationic protein μg/l, was 3070 before and 4651 after the low-salt treatment period, on average. In the high-salt treatment group, it was 12 192 μg/l vs 11 803 and in the placebo group 3942 vs 4144, respectively. Salt chamber treatment had no effect on sputum eosinophil or neutrophil cell numbers. CONCLUSIONS: The reduction in hyper-responsiveness observed in the previous study is probably not due to the effect on eosinophilic inflammation.