Good definitions, research lacking for COPD-asthma overlap

ORLANDO – Experts agreed that asthma and chronic obstructive pulmonary disease (COPD) overlap syndrome, referred to as ACOS, is an area in dire need of more careful study to give clinicians data they can actually use.

The topic is even more pressing given the growing interest and research into biological treatments for asthma and consideration of their possible use in COPD, experts said at the joint congress of the American Academy of Allergy, Asthma, and Immunology and the World Asthma Organization. Their remarks came in what was ostensibly a “debate” on whether ACOS is a distinct entity requiring special treatment but largely turned into a discussion about gaps in knowledge on the topic.

The dilemma, they said, is that the research tends to look almost exclusively at extreme cases, with asthma studies excluding COPD patients and COPD studies excluding asthma patients.

“The problem here is that it has not been defined in a way that everyone agrees on – that does create a problem because, if there’s no consensus on the diagnostic criteria, then it may be difficult to study this overlap,” said Donald Tashkin, MD, director of the pulmonary function laboratories at the University of California, Los Angeles. “Because there is no agreement on how to diagnose ACOS, it hasn’t been studied with respect to its responsiveness to different treatment options.”R. Stokes Peebles Jr., MD, professor of allergy, pulmonary, and critical care medicine at Vanderbilt University Medical Center, Nashville, Tenn., said that, although the number of published articles on ACOS has skyrocketed over the last several years, review articles have outnumbered original research articles.