The biochemistry of asthma

Background: Asthma is not one disease. Different patients have biochemically distinct phenotypes. Scope of review: Biomarker analysis was developed to identify inflammation in the asthmatic airway. It has led to a renewed interest in biochemical abnormalities in the asthmatic airway. The biochemical determinants of asthma heterogeneity are many. Examples include decreased activity of superoxide dismutases; increased activity of eosinophil peroxidase, S-nitrosoglutathione reductase, and arginases; decreased airway pH; and increased levels of asymmetric dimethyl arginine. Major conclusions: New discoveries suggest that biomarkers such as exhaled nitric oxide reflect complex airway biochemistry. This biochemistry can be informative and therapeutically relevant. General significance: Improved understanding of airway biochemistry will lead to new tests to identify biochemically unique subpopulations of patients with asthma. It will also likely lead to new, targeted treatments for these specific asthma subpopulations. This article is part of a Special Issue entitled Biochemistry of Asthma. (C) 2011 Published by Elsevier B.V.