Asbestos exposure as a cause of immunological stimulation.
Twenty immunological parameters were determined for 37 asbestos-exposed workers with no radiographic pulmonary fibrosis and 132 asbestosis patients, 37 of whom formed a matched referent group for the non-diseased workers. No clear differences between the matched groups were found for the autoantibodies tested, but the prevalence of autoantibodies was increased in both groups in comparison with the prevalence among Finnish blood donor candidates. This phenomenon may reflect a general immunological activity caused by asbestos dust, and this immunological activity may act as an adjuvant in immunisation. The patients revealed a high level of IgA, C3, C4 and alpha-1-antitrypsin. This result indicates that these factors may be related to the development of asbestosis, and could therefore be utilized in the evaluation of diffuse pulmonary fibrosis among workers with asbestos exposure.