Circulating immune complexes and antiglobulins (IgG and IgM) in asbestos-induced lung fibrosis.

Thirty-nine asbestos workers were examined with respect to the presence of IgG and IgM antiglobulins and circulating immune complexes. The overall incidence of raised levels of IgM antiglobulins and immune complexes was 63 and 28%, respectively. In the group positive for immune complexes, IgM antiglobulins were found more frequently than in those asbestos workers lacking immune complexes. However, all cases with the highest levels of IgM antiglobulins had normal or only slightly elevated levels of immune complexes. IgG antiglobulin levels were not elevated in asbestos workers. Asbestos workers with IgG antinuclear antibodies had the highest incidence of elevated levels of immune complexes.