Objective: To approach the role of tumor necrosis factor-alpha (TNF-alpha) and tumor necrosis factor receptor II (TNFR II) gene polymorphisms in genetic susceptibility to silicosis and their interaction with silica-dust exposure.
Methods: Two hundred and fifty-nine cases of silicosis and three hundred and forty-one silica-dust exposure workers (control) were selected, and the cases of silicosis were divided into three subgroups based on the various stages of I, II and III. Exposure history, pneumoconiosis history and past history of each subject were obtained by questionnaire. 3 ml peripheral venous blood was drawn from each subject. Using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) techniques, TNF-alpha and TNFRII gene polymorphisms were analyzed.
Results: In both group matching and 1:1 paired matching, there was no significant difference between cases of silicosis and workers in control in distribution frequencies of G/A + A/A (TNF-alpha-308) and T/G + G/G (TNFRII 196) genotypes. The risk of silicosis in those with G/A + A/A genotype was 6.74-fold higher than G/G genotype (OR = 6.74, 95% CI: 1.01 approximately 44.99) in subjects whose exposure time was less than 15 years.
Conclusion: TNF-alpha and TNFR II gene polymorphisms did not play an important role in susceptibility to silicosis of Han race. There was interaction between polymorphism of TNF-alpha gene promoter and exposure time in the occurrence of silicosis. The risk of silicosis in those with G/A + A/A genotype was significantly higher than G/G genotype in low accumulative exposure.