PON1 gene polymorphisms in patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterised with oxidative stress. Paraoxonase 1 (PON1) is an enzyme, coded by PON1 gene, with distinctive antiatherogenic and antioxidative roles. We aimed to investigate the frequencies of Q192R, L55M and -108C>T polymorphisms and association of those polymorphisms with paraoxonase and arylesterase activities in patients with COPD.

PON1 genotype was determined by PCR-restriction fragment length polymorphism method. PON1 activity was measured by paraoxon and phenylacetate.

Only -108C>T polymorphism resulted in significantly different distribution of genotypes and alleles, with higher frequency of TT genotype and T allele in patients compared with control subjects. Moreover, T allele (OR 2.29 (95% CI 1.54 to 3.41); p<0.001) as well as TT genotype (OR 5.00 (95% CI 2.19 to 11.43); p<0.001) showed an association with the disease. -108C>T polymorphism was suggested as a significant diagnostic predictor for the disease (OR (95% CI) 2.65 (1.53 to 4.59), p=0.001), with an area under the receiver operating characteristic curve of 0.90 (95% CI 0.84 to 0.93) and with 83.90% of correctly classified cases.

Higher frequency of TT genotype and T allele could contribute to the observed reduction of PON1 activity in patients with COPD. T allele and TT genotype are associated with COPD, and the PON1-108C>T polymorphism could be a potential predictor of the disease.