ABSTRACT
<p><b>BACKGROUND</b>Cyclooxygenase-2 (COX-2) is overexpressed during airway inflammation in chronic obstructive pulmonary disease (COPD) patients. Single nucleotide polymorphisms (SNPs) in the COX-2 promoter might contribute to differential COX-2 expression and subsequent interindividual variability in susceptibility to COPD. We investigated the association between COX-2 (-765G > C, -1195G > A) polymorphisms and COPD susceptibility in Japanese and Chinese patients.</p><p><b>METHODS</b>COX-2 genotypes were determined by polymerase chain reaction, restriction fragment length polymorphism in 230 COPD patients (103 Japanese and 127 Chinese) and 273 healthy controls (129 Japanese and 144 Chinese).</p><p><b>RESULTS</b>The frequency of -1195AA homozygote was significantly higher than the controls in Chinese COPD (adjusted OR = 2.43, 95%CI 1.14 - 4.19), Japanese COPD (adjusted OR = 2.25, 95%CI 1.06 - 4.76) and combined COPD groups (adjusted OR = 2.26, 95%CI 1.34 - 3.99). There was no difference in COX-2 -765G > C polymorphism between COPD and control groups in either Japanese or Chinese, while more Chinese individuals carried the -765C allele than Japanese in both groups (15.3% vs. 2.9% in COPD, 18.8% vs. 5.5% in control). Chinese individuals with the haplotype -765G:-1195A were at higher risk for COPD (adjusted OR = 1.93, 95%CI 1.05 - 3.55).</p><p><b>CONCLUSIONS</b>The COX-2 -1195AA genotype is associated with increased risk for COPD in both Japanese and Chinese individuals. Although COX-2 -765G > C polymorphism was not associated with COPD in either ethnic group, the -765C allele frequency was higher in Chinese than Japanese and haplotype -765G-1195A may confer susceptibility to COPD in Chinese.</p>