Pulmonary disposition of gallium-67 in patients with Pneumocystis pneumonia: an analysis using bronchoalveolar lavage

Gallium-67 localizes to the cellular fraction of bronchoalveolar lavage (BAL) fluid in patients with sarcoidosis, idiopathic pulmonary fibrosis, as well as normal subjects. To further study 67Ga disposition in BAL fluid, 11 patients with Pneumocystis carinii pneumonia (PCP) and 8 patients with a variety of other lung diseases, underwent BAL 24 hr after 67Ga injection. Compared to the non-PCP patients, PCP patients had high uptake gallium scans at 24 and 72 hr, and showed significantly increased radioactivity in both unfractionated lavage and in the acellular, supernatant fraction of BAL. The mean ratio of total supernatant/cell pellet radioactivity was also higher in patients with PCP (1.23 +/- 0.27 versus 0.24 +/- 0.05, p less than 0.01). Supernatant radioactivity correlated with the presence of neutrophil alveolitis, but not with BAL transferrin concentrations. We conclude that neutrophil alveolitis in PCP promotes 67Ga accumulation in the acellular fraction of BAL fluid. However, the high uptake 67Ga scans observed in PCP patients without neutrophil alveolitis suggest that the mechanism of pulmonary uptake of 67Ga is not fully elucidated by BAL fluid analysis alone.