Background: Initial investigations demonstrated a deficiency of glutathione (GSH) in the epithelial Lining fluid (ELF) of HIV-seropositive patients, In a recent study, our laboratory was unable to document such a deficiency. The current study was performed in an attempt to reconcile those disparate findings. Study objectives: To determine if ELF GSH decreases over time in asymptomatic HIV-seropositive subjects. Design: Prospective, longitudinal study. Setting: Major university medical center. Patients or participants: Thirty-three asymptomatic HIV-seropositive volunteers. Interventions: None. Measurements and results: BAL was performed on 33 asymptomatic HIV-seropositive subjects at baseline, 6 months later, and 12 months later. The volume of ELF and the concentration of GSH and oxidized GSH were determined. The concentration of total GSH in ELF was 689.0 +/- 100.4 mu M. This significantly decreased when measured 6 and 12 months later (355.9 +/- 41.7 mu M, and 397.9 +/- 52.7 mu M, respectively, p=0.01, compared with baseline, both comparisons). Significant decreases were also noted in the HIV-seropositive subjects who smoked cigarettes (baseline - 762.6 +/- 142.4 mu M; 6 months - 373.7 +/- 45.9 mu M; 12 months - 459.3 +/- 73.8 mu M, p<0.03, for baseline vs 6 months, and baseline vs 12 months). In nonsmoking HIV-seropositive subjects, there was a decrease in ELF GSH over time, but it did not reach statistical significance (baseline - 589.1 +/- 138.2 mu M; 6 months - 335.3 +/- 74.1 mu M; 12 months - 345.8 +/- 74.0 mu M, p>0.1, all comparisons), The percentage of total GSH in the oxidized form was similar at all three time points (baseline - 3.8 +/- 0.5%; 6 months - 3.1 +/- 0.5%; 12 months - 3.9 +/- 0.9%, p>0.1, all comparisons). Conclusions: The current study demonstrates that the GSH level in ELF is significantly decreased in HIV-seropositive subjects 6 and 12 months after the initial determination.