Immunological reflections on asbestos.

As a pulmonary immunologist interest in all forms of immune injury to the lung, I have had some experience with related minerals, such as silica and coal mine dust. When compared to the immunologic aspects of silicosis or coal workers' pneumonitis (CWP), the bulk of the immunologic evidence concerning asbestosis is scanty and unimpressive. To begin with, most of the experimental work is irrelevant because it dealt with doses that were much too high. Moreover, infected rats were often the experimental animals, there were no attempts to distinguish effects caused by asbestos from those caused by the almost universal opportunistic infections by mycoplasmas, and finally too much of the work used irrelevant experimental procedures like injecting the asbestos fibers into some organ or lumen. Aside from this we can ask a few questions, speculate a little, suggest a few avenues of approach, award some bouquets, and cast a few stones. The pleural plaques contain collagen and I would expect that there would be immunofluorescent localization of globulin at these sites, but Zaidi (1) and Turner-Warwick (2) in separte studies on limited material did not find such. Do these people produce antilung connective tissue antibodies seen in other chronic pulmonary disease? Turner-Warwick has found them, but was unimpressed with the frequency in the small population of cases she has studied. Similarly, since IgA is known to be greatly increased in miners with CWP, could one look for IgA levels in patients with asbestosis? Turner-