Objective: Interstitial lung disease (ILD) is a severe adverse event of gefitinib therapy. However, the mechanism still remains unclear. The objective of this study was to examine whether or not oxidative stress, one of the common factors in drug-associated ILD, is involved in the pathogenesis of gefitinib-induced ILD.
Patients and methods: Using an enzyme-linked immunosorbent assay (ELISA), we measured the concentration of serum thioredoxin (Trx), a redox-active protein with antioxidative effects, in 44 patients treated with gefitinib, including three patients who had ILD.
Results: In patients who had gefitinib-induced ILD, serum Trx levels were significantly elevated. They decreased after cessation of gefitinib therapy accompanying clinical improvement of ILD.
Conclusion: It was suggested that oxidative stress may be involved as a part of mechanisms causing or worsening gefitinib-induced ILD.