Researchers Discover Why Steroid Treatment For COPD Is Ineffective
Posted Oct 18 2011 5:46pm
Chronic obstructive pulmonary disease (COPD) leads to persistent inflammation of the airways and is typically managed with corticosteroids, a class of anti-inflammatory medication. However, corticosteroids do not improve survival nor alter the progression of COPD and may reduce lung symptoms as little as 20 percent. A new study led by researchers at the Johns Hopkins Bloomberg School of Public Health, found why corticosteroids do not work well for COPD patients and how additional treatment with sulforaphane—an ingredient of broccoli and other vegetables—can improve the effectiveness of corticosteroids. The study was published online October 17, 2011, in advance of print in the Journal of Clinical Investigation.
COPD is a major public health problem for both the developed and the developing world, and is most often caused by cigarette smoking or exposure to pollutants from combustion. Characterized by chronic bronchitis and emphysema, COPD is the third leading cause of death in the U.S. and affects 24 million Americans and 210 million people worldwide.
Histone deacetylase 2 (HDAC2) is critical component in a chain of reactions that enable corticosteroids to reduce inflammation. However, HDAC2 is substantially reduced in the lung tissue of individuals with COPD. In the study, Johns Hopkins researchers found that S-nitrosylation causes HDAC2 dysfunction and leads to corticosteroid insensitivity in the alveolar macrophages of the lungs of individuals with COPD. S-nitrosylation of HDAC2 occurs from exposure to cigarette smoke, a primary cause of COPD.