Glutathione (GSH) is decreased in cystic fibrosis (CF) airways, thus its resupply by inhalation has been employed to restore antioxidant defense. CF airways present however increased activity of gamma-glutamyltransferase (GGT), the enzyme specifically capable of degrading GSH, and thus inhaled GSH might be promptly catabolized. In addition, prooxidant reactions are known to originate during GGT-mediated GSH catabolism. We determined levels of GGT in the sputum samples obtained from a previously published trial of GSH inhalation treatment, and analyzed their correlations with inflammatory markers and FEV1% values. Results indicate that differentiating patients with increasing vs. decreasing GGT activity - as measured in sputum before and after the six months duration of the study - may discriminate subjects more likely profiting from inhaled GSH, as opposed to those with increasing GGT in which these treatments might even produce aggravation of the damage.
Keywords: Cystic fibrosis; Gamma-glutamyltransferase; Glutathione; Inflammation.
Copyright © 2016 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.