Immune response in shipyard workers with x ray abnormalities consistent with asbestos exposure.

The association of cellular and humoral immune responses with asbestos exposure was studied in two groups of 150 workers each from a shipyard population and compared with a population of Red Cross blood donors. One of the shipyard groups had both chest x ray evidence of asbestos exposure and work assignments that necessitated direct handling of asbestos. The other shipyard group had normal chest x ray films and no job assignments involving the direct handling of asbestos. Cellular immune responses studied were mitogen activation and measures of T helper and T suppressor cells. Humoral immune measures were IgG, IgA, and IgM. In shipyard workers with asbestos related x ray abnormalities there was a significant increase in pokeweed mitogen stimulation. In both shipyard groups compared with Red Cross blood donors were found (1) significantly higher IgG and IgA levels and (2) greater numbers of T helper and T suppressor cells; because of the disproportionately large number of T suppressor cells, Th/Ts ratios were lower than in the Red Cross controls. Observations of differences in humoral and cellular immune response may point the way to the early diagnosis of the clinical manifestation of asbestos related disease.