Background. Inhalation treatments with glutathione (GSH) have gained interest among CF patients. GSH is a primary antioxidant whose levels are significantly decreased in lungs during inflammatory processes. However the results attained so far remain disappointing. One of the possible reasons may lie in the fact that CF lungs often present with increased levels of gammaglutamyltransferase (GGT), an enzyme secreted by inflammatory cells, capable of degrading GSH.

Hypothesis and objectives. The hypothesis to be verified was whether the different levels of airways GGT in CF patients might modulate the effects of GSH-based therapies. It is of importance to clarify whether GSH inhalation therapies are truly beneficial, useless or even – in selected conditions – potentially dangerous.