Relationship Between Polymorphisms In SP-D And Susceptibility To COPD

Object: We genotyped two single-nucleotide polymorphisms(SNPs) in surfactant protein D gene exon1 rs721917 loci,exon5 rs2243639 loci in the population and to analyze the su-sceptibility between the two SNPs loci in chronic obstructive pulmonary disease(COPD) of these population.Method: A case-control study of 117 COPD patients were randomly recruited from Qingdao Municipal Hospital as COPD group and 117 unrelated, gender-matched, age-matched control subjects enlisted from health examination center as control group. Genomic DNA was extracted from whole blood with WB genomic DNA extract kit of the 234 subjects. The SP-D gene rs721917 and SP-D gene rs3343639 polymorphisms were determined by polymerase chain reaction(PCR)-DNA sequencing.Results:(1).The alleles frequencies and genotypes frequencies were significantly different between the COPD group and control group for SP-D gene rs721917 loci(χ2=5.200、6.063,P<0.05)(alleles frequency:C:56.4%VS66.7%,T:43.6%VS33.3%,genotypes frequency:CC:28.2% VS 41.0%,TC:56.4%VS51.3%,TT:15.4%VS7.70%).(2).In the SNP of the SP-D gene rs721917,compared with genotype CC,the genotype TC failed to increase the risk of COPD(OR=1.600,95%CI=0.910-2.814,P=0.103),while the genotype TT may increase the risk of COPD(OR=2.909,95%CI=1.615-7.261,P=0.020). Compared with allele gene C, allele gene T may increase the risk of COPD( OR=1.545,95%CI=1.602-2.249,P=0.023).(3).The alleles frequencies and genotypes frequencies were no different between the COPD group and control group for SP-D gene rs2243639 loci(χ2=0.018、0.342,P>0.0 5)(alleles frequency: G:85.9% VS 86.3%,A:14.1%VS13.7%;genotypes frequency: GG: 74.4% VS 76.1%,GA:23.1% VS 20.5%,TT:2.5% VS 3.4%).(4).In the SNP of the SP-D gene rs2243639 loci,compared with genotype GG,the genotype GA failed to increase the risk of COPD(OR=1.151,95%CI=0.616-2.148,P =0.659)and the genotype AA also failed to increase the risk of COPD(OR=0.767,95% CI=0.167-3.529,P=0.734). Compared with allele gene G, allele gene A may not a risk fact-or for COPD(OR=1.036,95%CI=0.614-1.750,P=0.894).Conclusion:(1)SP-D gene SNP site rs721917 polymorphism and T allele at rs721917 loc-i of SP-D are more susceptible to COPD.(2)The SP-D gene SNP site rs2243639 was not associated with the susceptib-ility to COPD.