Asthma is usually treated very effectively with inhaled steroids but for some patients, taking steroid tablets is the only way of controlling their condition, and this can cause considerable side effects. Unfortunately a sub-group of people with severe asthma fail to show clinical improvement, even with high doses of oral steroids, limiting their treatment options.
Professor Tak Lee, Director of the MRC-Asthma UK Centre in Allergic Mechanisms of Asthma at King's College London and Imperial College, who was involved in the latest study, explained its importance: 'This research is really exciting and points the direction towards potential new strategies for reversing steroid resistance. This has major implications for how to treat patients with severe asthma and could also substantially reduce the use of NHS resources.'
The team's results imply that steroid treatment works, at least in part, by inducing the T-cells of the immune system to synthesise a secreted signalling molecule, called IL-10. This molecule can inhibit the immune responses that cause the symptoms of allergic and asthmatic disease.
Unlike T-cells from healthy individuals, or patients that respond to steroids, T-cells taken from patients who are steroid resistant do not produce IL-10 when cultured in vitro with the steroid, dexamethasone.
However, the researchers found that when vitamin D3 was added to the culture medium along with dexamethasone, this defect was reversed and the previously steroid-resistant cells were able to respond to the tre
Contact: Gemma Bradley
King's College London