Immunological studies of patients with asbestosis. I. Studies of cell-mediated immunity.

A variety of cancers have been documented in patients exposed to asbestos dust. Since a deranged immune system may play a rôle in cancer development, the general level of immunocompetence was studied in a group of twenty-six patients with radiographically defined asbestosis, who might be at risk of developing asbestos-related neoplasms. Statistical comparisons were made with a comparable control group. A disproportionate number of the patients displayed cutaneous energy to certain recall antigens and to 2,4-dinitrochlorobenzene. In vitro studies of cellular immunity, as evaluated by phytohaemagglutinin-induced proliferative and cytotoxicity assays, showed significantly lower values amongst the patient group. Serum inhibitors of mitogen-induced lymphocyte transformation were also detected in several of the patients. The possible significance of these findings is discussed.