[Immunological aspects of asbestos-related diseases].

Abstract

Asbestos is a generic name for a group of silicate minerals. The most common are chrysotile, crocidolite, amosite, tremolite and anthophyllite. Exposure to asbestos may cause asbestos-related non-malignant diseases of the lung and pleura, including asbestosis, pleural plaques, diffuse pleural fibrosis, small airway disease, and malignant diseases such as lung cancer and malignant mesothelioma. Inhaled asbestos fibres deposit in the distal regions of the respiratory system where they interact with epithelial cells and alveolar macrophages, and trigger active immunological response which leads to a slowly progressing lung fibrosis. Asbestos may affect immunocompetent cells and induce malignant transformation of mesothelial cells. It is still not clear whether asbestos causes mesothelioma directly or indirectly. There is a general opinion that malignant mesothelioma is a complex tumour that results from the accumulation of multiple genetic alterations over many years. There is no specific antibody for malignant mesothelioma as yet which could act as a single diagnostic tool. Recent studies have demonstrated that asbestos acts on peripheral T cells as superantigen and that in malignant mesothelioma patients there is an overexpression of the Bcl-2 gene on peripheral CD4+ T cells. These findings contribute to better understanding of biological effects of asbestos in respect to the duration and intensity of exposure.