Objective: To explore the relationship between the polymorphism of Interleukin-1 and the pneumoconiosis susceptibility.
Methods: Eighty patients with silicosis and 45 with coal workers' pneumoconiosis (CWP) were selected while 125 male workers, Han nationality in the same workplace as the patients were selected as the controls. Between the patients and the control, the differences of age and cumulative length of service were less than five years and two years, respectively. The controls were exposed to dusts but did not suffer from pneumoconiosis. Moreover, the patients and the controls were paired by 1:1. DNA was extracted from leucocytes by the hydroxybenzene chloroform method. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) techniques and PCR were used to examine polymorphism of IL-1alpha (-889), IL-1beta (-511) and IL-1Ra (+2018) and variable number of tandem repeats (VNTR) of IL-1Ra. After the preliminary experiment, the most adaptive PCR reaction, the restriction enzyme digest and electrophoresis system were used.
Results: The difference in IL-1alpha (-889) 1/2 + 2/2 between the pneumoconiosis patients and the controls was significant (P < 0.01). The result of conditional Logistic regression showed that heterozygote and allele 2 of IL-1a (-889) were risk factors of pneumoconiosis. The difference in the genotype frequencies of IL-1beta (-511) 1/2 + 2/2, IL-1Ra (+2018) 1/2 + 2/2 and IL-Ra VNTR1/2 + 2/2 between the patients and the controls were not statistically significant (P > 0.05).
Conclusion: IL-1alpha (-889) gene polymorphism is related to pneumoconiosis. Workers with IL-1alpha (-889) allele 2 are susceptible to the pneumoconiosis. The relationship between IL-1beta (-511), IL-1Ra (+2018), IL-1Ra VNTR genes polymorphisms and pneumoconiosis are not found.