Enhanced alveolar macrophage Ia antigen expression after asbestos inhalation.

Asbestos is a disease characterized by pleural and interstitial pulmonary fibrosis resulting from the inhalation of asbestos dust (1). Although the pathogenesis of the disease is not fully understood, immunologic mechanisms are suspected to play an important role in asbestos-mediated lung injury. There is also evidence that alveolar macrophages (AM) may be pivotal in this regard. As an extension of earlier studies, the authors have recently shown that both amphibole (crocidolite) and serpentine (chrysotile) asbestos inhalation are associated with augmented antigen-directed release of interleukin 1 (IL 1) and interleukin 2 (IL 2) during in vitro culture. Because IL 1 activity is known to be under the control of the 1 region of the major histocompatibility complex, the present study was undertaken to assess the effects of crocidolite and chrysotile asbestos inhalation on Ia antigen expression by AM. By using a defined rat model the longer-term effects of asbestos inhalation were studied in one set of animals at a time contemporaneous with the earlier interleukin study. Another set of rats was also studied to monitor the shorter-term effects of asbestos exposure. The results indicate that both amphibole and serpentine asbestos inhalation in the rat are associated with enhanced Ia expressitivity onmore » AM.« less