Objective: To investigate the polymorphism of interleukin-10 (IL-10) gene promoters in Chinese Han people, and to disclose whether such polymorphism is associated with susceptibility to chronic obstructive pulmonary disease (COPD).
Methods: After the process of extracting genomic DNA from blood of 94 health smokers and 88 COPD smokers by use of phenol-chloroform-isoamyl alcohol, three single nucleotide polymorphism (SNP) sites in IL-10 gene promoter marked as -1082G/A,-819C/T,-592C/A were determined by polymerase chain reaction/restriction fragment length polymorphism analysis.
Results: Eleven different promoter genotypes were detected from all of the 182 smokers, and AA*TT*AA, AA*TC*AC, AA*TC*AA genotypes accounted for about 80% of genotypes in the research subjects. Two previously unreported haplotypes of IL-10 gene promoter (ATC and ACA) were found in Chinese Han people by analyzing the promoter genotypes. -1082G/A and -592C/A SNP sites polymorphisms were not associated with susceptibility to COPD, whereas the genotypes of -819C/T SNP site were associated with susceptibility to COPD in Chinese Han people. In respect to the alleles frequencies of the three SNP sites respectively, the Chinese Hans were similar to Japanese, but different from whites.
Conclusion: Polymorphism of IL-10 -819C/T SNP site is associated with susceptibility to COPD in Chinese Han people; at least five haplotypes of IL-10 gene promoter (ATA, ACC, GCC, ATC and ACA) exist in Chinese Han people.