**Asthma-COPD Overlap Syndrome (ACOS): Current Understanding and Future Perspectives**

Irina Bobolea and Luis Alejandro Pérez de Llano

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/62412

#### **Abstract**

This chapter resumes our current understanding of asthma–chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS), pretending to offer a compre‐ hensive approach for the practicing physician, and provides some future perspectives on this entity.

Although different studies recognize the presence of ACOS, the detection, diagnosis, and treatment of these patients in clinical practice are not always simple and are subject to different interpretations. These patients are of special interest, because they are usually excluded from clinical trials with new medications, and also represent a clinically very important and quite prevalent population, with particular characteristics: more respiratory symptoms, frequent exacerbations, and worse health-related quality of life. They are also characterized by an increase in comorbidity and a greater consumption of health care resources compared to patients with only asthma or COPD alone.

There are currently no universally accepted, validated criteria for the diagnosis of ACOS. The differences between clinical guidelines are discussed here (GINA 2014, GEMA 2015, and GOLD 2014). However, to obtain clear and validated criteria, we think that further research about the underlying mechanisms is needed.

Several potential pathways that might lead to the adult presentation of ACOS are revised. The therapeutic recommendations of the Spanish consensus guideline for patients with overlap phenotype COPD–asthma are provided, and other possible future therapies are discussed in this chapter.

**Keywords:** ACOS, ACOS criteria, ACOS treatment, asthma, COPD

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
