Lysosomal gold accumulations in pulmonary macrophages

Although soluble gold has been widely used in the treatment of rheumatoid arthritis, little is known about the distribution of gold deposits in extra-articular tissues. In the synovial lining cells and articular cartilage, the morphology of lysosomes containing gold, the aurosomes, is well documented. Because gold may cause pulmonary injury, the morphology and distribution of gold deposits in pulmonary tissue should be recognized. We found morphologically typical aurosomes with electron-dense membranes and granules, giving the spectrum of gold in electron microprobe analysis, in the interstitial and alveolar macrophages in the open lung biopsies of 3 patients who had received gold treatment but not in 12 patients who had not received gold treatment. In contrast to previous studies, aurosomes were not found in the endothelial cells.