Studies of Reciprocal Relation Between NK Cell Activities and Interferons on Asbestosis

Abstract

Immunological abnormality in 14 patients with asbestosis was investigated for natural killer (NK) cells from peripheral blood mononuclear cells (PBMC) and interferon (IFN). There were 7 males and 7 females (mean age 61 years; range 42-73 years) who were free of complications such as tuberculosis, carcinoma, or steroid therapy. There were 4 cases of type 1 and 10 cases of type 2 as described in the ILO pneumoconiosis classification. They are all textile workers with a mean duration of 17 years (3-30 years) since the first exposure to chrysotile. Controls matched by age and sex were selected from a population without occupational exposure to asbestos. NK cell activity in the patients with asbestosis was significantly lower than in the controls. But the population of NK cells in PBMC showed no significant differences for the two group. Exogenous IFN enhanced NK cell activity of controls and 3 patients with asbestosis, while it did not enhance activity in 7 patients. Furthermore, PBMC from controls and patients with asbestosis produced IFN-α type after stimulation with Sendai virus. The results were that IFN-α levels in patients with asbestosis were significantly higher than those of the controls. The number and mechanism of suppressor T cells in patients with asbestosis showed no significant difference when compared with the controls. These findings may indicate evidence that links fundamental disturbances of body defence mechanism in patients with asbestosis.