The relationship between polymorphisms of interleukin-4 gene and silicosis.

Abstract Objective To explore the relationship between polymorphisms of interleukin-4 (IL-4) gene (−33, +45, intron3, +429, +448) and the susceptibility of silicosis. Methods A case-control study was carried out. 101 silicosis patients were selected as cases. As strictly matching, 121 of non silicosis workers were selected as the controls. The polymophisms of IL-4 (five locus) were detected by the method of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) techniques. Results The GA genotype in the IL-4+429 locus and the CC genotype in the IL-4+448 locus were found. The frequencies of AA, GG and AG of IL-4+45 locus in the cases were 55.4%, 10.9%, and 33.7% and in the controls were 62.0%, 11.6%, and 26.4%. The differences between cases and controls were not significant. The frequencies of B1B1, B2B2, and B1B2 of intron3 VNTR locus in the cases were 73.3%, 1.0%, and 25.7% and in the controls were 68.6%, 1.7%, and 29.8%. The differences were not significant. The frequencies of TT, CC, and CT in −33 locus in the cases were 55.4%, 11.9%, and 32.7% and in the controls were 69.4%, 4.1%, and 26.4%. The differences were significant ( P =0.034). Conclusion The relationship between genetic polymorphism of IL-4-33 site and silicosis has been found and −33TT is a protective genotype for silicosis.