Humoral immunological profile of workers exposed to asbestos in asbestos mines.

Humoral immunological profile including immunoglobulins IgG, IgA, IgM, C-reactive protein, rheumatoid factor, antinuclear antibodies and circulating immune complexes were studied in a representative sample of 36 workers suffering from asbestosis (group A), 35 workers who are exposed to asbestos but not having evidence of asbestosis (group B) and 28 control workers (group C). Mean IgG and IgA levels were found to be significantly higher in the two exposed groups than in the controls. Circulating immune complexes of IgG, IgA and IgM class were detected in a significant percentage of cases in exposed groups than in controls. In groups A and B, the percentage of positive ANF cases was much higher than in the controls. The results suggest that immunological changes are associated with exposure to asbestos and these may play an important role in the pathogenesis of the disease process.

Humoral immunologic dysfunction in silicosis.

Immunoglobulins may play an important role in the evolution of silicosis, and their determination may serve as a helpful criterion in the diagnosis of silicosis. Serum immunoglobulin levels were studied in slate pencil workers (130) exposed to high concentrations of silica dusts and non-exposed controls (50). Significantly higher levels of immunoglobulins were observed in the silica exposed individuals. A rising trend in the serum IgG from a mean of 1373 mg/dl in control group to 2193.68 mg/dl in exposed group (conglomerate) and IgM from 140.51 mg/dl in control to 201.19 mg/dl in exposed group (conglomerate silicosis) was observed with increase in the duration of dust exposure. Highest mean levels of IgG (2193.60 mg/dl) and IgM (201.19 mg/dl) were observed in the workers having conglomerate silicosis. The results indicate that though, the levels of immunoglobulins were raised in subjects exposed to silica, this parameter may be of limited value for determining progressive of silicosis.