Serum interferon levels and natural killer cell activity in patients with asbestosis

Natural killer cell activity and serum interferon levels were measured in 30 patients with asbestosis. The chest radiographs showed type 1 changes (ILO pneumoconiosis classification) in nine, type 2 changes in 19, and type 3 changes in two. Thirty control subjects matched for age, sex, and smoking habit were also studied. Patients with asbestosis had significantly higher serum interferon levels than the controls. There was no significant difference in natural killer cell activity between patients with asbestosis and normal controls.