Evaluation of cellular immunity in patients with asbestosis and workers exposed to asbestos

Introduction: A large number of studies have proved a relationship between maligant mesothelioma and workers exposed to asbestos. The purpose of this study was to evaluate the degree of immunocompetence of the asbestos workers in comparison with non asbestos workers. Methods and materials: In this study 7 asbestotic patients, 73 workers exposed to asbestos and 59 controls from 2 Farsit factories in Iran were examined . Some aspects of immunological response were evaluated in 7 patients, 16 asbestos workers and 23 controls . Delayed hypersensitivity by using PPD and candidin antigen in 57 asbestos workers and 29 controls were determined . Findings: Chest roentenogram showed no significant radiographic differences. Measurement of PHA response and counting T-cells and TG (T suppressor) cells indicated no significant difference in PHA response where as the number of T-cell in patients (34±14) and asbestos workers (34±16) was reduced in comparison with controls (59±21) and that of TG-cells in the former (15±6) and latter (19±8) was increased (9±3) compared with the controls( p>0.001). 61% of the asbestos workers had positive reaction to PPD and 65% of them had positive reaction to candida when compared with the controls (83% with PPD and 86% with candidin). Statistically the above results showed significant differences. Conclusion : Results show cell mediate immunodeficiency in asbestotic patients and asbestos workers , more than 11 years contact with asbestos. These defect is after long time contact with asbestos and before fibrosis sings with chest roentenogram .