Biomedical Engineering Reference
In-Depth Information
4
Asthma vs. COPD: Cellular and
Molecular Differences
Leonardo M. Fabbri, Fabrizio Luppi, Micaela Romagnoli, and
Lorenzo Corbetta
Department of Respiratory Diseases, University of Modena and
Reggio Emilia, Via del Pozzo, Modena, Italy
I.
INTRODUCTION
COPD and bronchial asthma are considered two distinct chronic respiratory
disorders sharing two common functional features, airflow limitation and
bronchopulmonary inflammation (1,2). For clinical purposes, COPD is
defined on a spirometric basis, as a disease state characterized by airflow
limitation that is not fully reversible postbronchodilator FEV
1
<
80% pre-
dicted with a FEV
1
=
FVC
<
70% and is progressive in a subject with a cur-
rent or previous history of tobacco smoking or exposure to noxious agents
(2). Similarly, asthma is defined on a spirometric basis, i.e. a disease state
characterized by airflow limitation that is often reversible either sponta-
neously or with treatment (1). The difference between not fully reversible air-
flow limitation of COPD and often reversible airflow limitation of asthma is
minimal and makes it difficult in some cases to distinguish the two disease
states. In addition, in asthma, airflow limitation may also progress, even
if at lesser extent as compared to COPD, and thus it may shift from rever-
sible to not reversible as in COPD (3). Chronic airway inflammation is pre-
sent in both COPD and asthma, even though the characteristics of the
inflammatory process are markedly different in the two disease states (4,5).
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