A highly statistically significant correlation was found between asbestosis and impaired responsiveness in skin reaction to intermediate and second strength tuberculin and SK-SD. Considering ANA incidence these antibodies were found with higher frequency in asbestos workers who lacked a cutaneous response to the recall antigens. In asbestosis cases peripheral blood lymphocyte profiles are also abnormal demonstrating low proportions of E-RFC. Moreover, MIF test results showed the impairment of this cytokine generation when lymphocytes were stimulated with SK-SD, PPD and PHA in asbestosis cases. The lymphocyte transformation study documents an impaired response mainly to a lower dose of PHA and ConA in asbestosis cases and in asbestos workers with ANA.