Regional differences in emphysema scores and BAL glutathione levels, in HIV-infected individuals

Study objectives: Evidence exists that HIV-seropositive individuals may be at increased risk for the development of precocious pulmonary emphysema. HIV infection is also associated with antioxidant deficiency in both the serum and lungs, and it is therefore possible that increased oxidant stress may contribute to parenchymal lung injury occurring in the setting of HIV. We sought to determine the regional distribution of emphysema and regional distribution of glutathione (GSH) concentrations among HIV-seropositive subjects with emphysema. Design: Cross-sectional evaluation of a prospective, longitudinal study. Setting: University teaching hospital. Subjects/measurements: HIV-seropositive subjects without AIDS-related pulmonary complications participating in a descriptive study of lung biology in HIV-seropositive individuals. Emphysema scoring and evaluation of emphysema lobar distribution was performed among 40 subjects with emphysema. Eleven subjects underwent BAL of the right middle lobe (RML) and tight upper lobe (RUL) with measurement of epithelial lining fluid (ELF) GSH in each lobe. Results: We found that the mean emphysema scores were much higher in the upper lobes compared to the rest of the lung. Mean GSH levels were significantly greater in the RUL compared to the RML. The regional differences were present in both smokers and nonsmokers. Conclusions: We conclude that in the setting of HIV, emphysemia is more prominent and lung GSH concentrations are higher in the upper lobes. We hypothesize that the increased GSH may represent a compensatory response to increased oxidant stress in the upper lobes.