Antinuclear factor (ANA) and rheumatoid factor (RF) were determined in 220 employees of an asbestos plant. The relationship of the appearance of the two factors to sex, age, smoking habit, duration of asbestos exposure and asbestos exposure level was studied. In 207 employees who had chest roentgenograms, the relationship of these two factors to pulmonary lesions and pleural lesions was examined.
Of the 220 employees, 33 (15%) had ANA and 7 employees (3.2%) had RF. ANA positive rate in the asbestos plant employees was significantly higher than in the control. Factors significantly correlated to their appearance could not be demonstrated. With the progress of pulmonary lesions the ANA positive rate significantly elevated, but ANA positive rate was not significantly correlated with pleural lesions.
RF did not show any significant correlation with any of the factors.
