Specific Genetic Mutations Do Not Affect Lung Function Response to Asthma Treatment

Therapy's effects on airway hyperresponsiveness, not lung function, was affected by genetic mutation.

Online PR News – 15-December-2009 – – Boston, MA – Contrary to previous studies which suggest that asthma patients with a specific genetic mutation might respond less favorably to certain treatments than those with a different mutation, researchers at Brigham and Women’s Hospital (BWH) found that patients with either mutation respond to combination treatment, and this treatment should be continued for these patients. These findings appear in the November 19 issue of The Lancet.
Some studies suggest that patients with the an amino-acid variation at a certain position in the ß2-adrenergic receptor benefit less from treatment with long-acting ß2 agonists than do those with a different mutation at the ß2-adrenergic receptor. The authors investigated whether there is a genotype-specific response to treatment with a longacting ß2 agonist in combination with an inhaled corticosteroid.
Adult patients with moderate asthma were enrolled in pairs of similar lung capacity and ethnic origin, according to which genetic mutation they had. Individuals in a matched pair were assigned to receive inhaled longacting ß2 agonist or a placebo. An inhaled corticosteroid was given to all participants during the treatment periods. Researchers measured lung function with standard measure of lung function with morning peak expiratory flow (PEF).
The team found that lung function did not differ between groups, but participants with the genetic mutation arginine-arginine did not benefit from the addition of longacting ß2 agonist in regards to airway hyperresponsiveness.
“Interestingly, we also found that African-Americans with one of the genetic variations did not improve with respect to lung function with the addition of the long-acting beta-agonist to the inhaled corticosteroid the way African-Americans with the other mutation did,” said Michael Wechsler, MD, of the Pulmonary Division at BWH. This may modify the risk benefit ratio of longacting beta agonists in this population.

About Brigham and Women's Hospital:-
Brigham and Women's Hospital (BWH) is a 777-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare, an integrated health care delivery network. In July of 2008, the hospital opened the Carl J. and Ruth Shapiro Cardiovascular Center, the most advanced center of its kind. BWH is committed to excellence in patient care with expertise in virtually every specialty of medicine and surgery. The BWH medical preeminence dates back to 1832, and today that rich history in clinical care is coupled with its national leadership in quality improvement and patient safety initiatives and its dedication to educating and training the next generation of health care professionals. Through investigation and discovery conducted at its Biomedical Research Institute (BRI), BWH is an international leader in basic, clinical and translational research on human diseases, involving more than 860 physician-investigators and renowned biomedical scientists and faculty supported by more than $416 M in funding. BWH is also home to major landmark epidemiologic population studies, including the Nurses' and Physicians' Health Studies and the Women's Health Initiative. For more information about BWH, please visit http://www.brighamandwomens.org/