(RxWiki News) Asthma and inflammation may seem like an obvious relationship, but that's not the case. New research suggests that the majority of patients with mild-to-moderate asthma may not respond to anti-inflammatory treatments.
According to a cross-sectional study, a large percentage of mild-to-moderate asthma sufferers have persistently non-eosinophilic disease.
This means is that current anti-inflammatory treatments do not work.
"If you have asthma, ask your doctor about new treatments."
This large group of asthma sufferers do not respond to traditional steroid treatments according to John Fahy, M.D., M.Sc., professor of medicine and director of the Cardiovascular Research Institute/University of California San Francisco Airway Clinical Research Center.
Eosinophilia is an increase in the amount of eosinophil cells. Eosinophil cells are white blood cells that the immune system produces to attack foreign bodies. Eosinophils also help regulate the reaction to irritants in asthma patients.
An excess of eosinophil cells can damage the airways of the lung and anti-inflammatory treatments are needed to reduce eosinophil levels.
The study was conducted by the National Heart, Lung and Blood Institute (NHLBI) Asthma Clinical Research Network and involved 995 patients suffering from mild-to-moderate asthma. Mucus samples were collected and for patients using an inhaled corticosteroid (ICS), only 17 percent of asthma patients had eosinophilia.
For patients who did not use an ICS, multiple mucus samples were collected. Out of all the samples, 22 percent had persistent eosinophilia, 31 percent had eosinophilia on at least one mucus sample and 47 had no sign of eosinophilia.
A two week combined treatment of anti-inflammatory drugs provided significant airway obstruction improvement for patients with eosinophilia. The combined treatment had no improvement in airway obstruction for persistently non-eosinophilic asthma patients.
This study has changed previous understanding about eosinophilia and its connection to asthma. Previously, only one mucus sample was collected and now the multiple samples collected over time have provided more accurate results.
Airway obstruction is still an issue and the lack of response to combined anti-inflammatory treatments in non-eosinophilic asthma patients means that new treatments need to be developed. Researchers and doctors should treat non-eosinophilic asthma patients as a unique subgroup of mild-to-moderate asthma sufferers.
Future research can focus on separating asthma patients with eosinophilia and those without eosinophilia. This distinction can lead to not only better treatments but also a better understanding of how asthma works.
This study was published of the January edition of American Journal of Respiratory and Critical Care Medicine.