Associations of Polymorphism of rs9944155, rs1051052, and rs1243166 Locus Allele in Alpha-1-antitrypsin with Chronic Obstructive Pulmonary Disease in Uygur Population of Kashgar Region.

Background: Previous studies conducted in various geographical and ethnical populations have shown that Alpha-1-antitrypsin (Alpha-1-AT) expression affects the occurrence and progression of chronic obstructive pulmonary disease (COPD). We aimed to explore the associations of rs9944155AG, rs1051052AG, and rs1243166AG polymorphisms in the Alpha-1-AT gene with the risk of COPD in Uygur population in the Kashgar region.

Methods: From March 2013 to December 2015, a total of 225 Uygur COPD patients and 198 healthy people were recruited as cases and controls, respectively, in Kashgar region. DNA was extracted according to the protocol of the DNA genome kit, and Sequenom MassARRAY single-nucleotide polymorphism technology was used for genotype determination. Serum concentration of Alpha-1-AT was detected by enzyme-linked immunosorbent assay. A logistic regression model was used to estimate the associations of polymorphisms with COPD.

Results: The rs1243166-G allele was associated with a higher risk of COPD (odds ratio [OR] = 2.039, 95% confidence interval [CI]: 1.116-3.725, P = 0.019). In cases, Alpha-1-AT levels were the highest among participants carrying rs1243166 AG genotype, followed by AA and GG genotype (χ2 = 11.89, P = 0.003). Similarly, the rs1051052-G allele was associated with a higher risk of COPD (OR = 19.433, 95% CI: 8.783-43.00, P < 0.001). The highest Alpha-1-AT levels were observed in cases carrying rs1051052 AA genotype, followed by cases with AG and GG genotypes (χ2 = 122.45, P < 0.001). However, individuals with rs9944155-G allele exhibited a lower risk of COPD than those carrying the rs9944155-A allele (OR = 0.121, 95% CI: 0.070-0.209, P < 0.001). In both cases and controls, no significant difference in Alpha-1-AT levels was observed among various rs9944115 genotypes.

Conclusions: rs1243166, rs9944155, and rs1051052 sites of Alpha-1-AT may be associated with the COPD morbidity in Uygur population. While rs1243166-G allele and rs1051052-G allele are associated with an increased risk of developing COPD, rs9944155-G allele is a protect locus in Uygur population. Alpha-1-AT levels in Uygur COPD patients were lower than those in healthy people and differed among patients with different rs1051052 AG and rs1243166 AG genotypes.