Impact of -1562 C/T polymorphism of MMP9 gene on COPD susceptibility in Polish patients

Introduction One of the hypotheses of COPD development suggests protease-antiprotease imbalance,which can cause degradation of extracellular matrix. As a consequence, the decline of lung function can be observed. Matrix metalloproteinase 9 (MMP9) is a proteolytic enzyme responsible for collagen digestion, and may contribute to COPD pathogenesis. In the MMP9 gene, a -1562 C/T polymorphism was found, and the -1562T allele is associated with increasing level of promoter activity. It may be argued that the above-mentioned allele can influence incidence of COPD. Aims and objective To investigate the potential role of -1562C/T polymorphism in COPD development. Eighty-three patients diagnosed with COPD according to the GOLD criteria, and 110 healthy control individuals were enrolled in the study. All cases have Polish Caucasians ethnicity. Methods DNA was extracted from peripheral blood using Invisorb Spin BloodMidi Kit following the manufacturer9s instructions (Invitek, Germany). The MMP9 -1562C/T polymorphism was typed by PCR-RFLP method using 59-GCCTGGCACATAGTAGGCCC-39 and 59-CTTCCTAGCCAGCCGGCATC-39 primers, and cutting with restriction enzyme SphI (Zhang, B. et al. Circulation , 1999; 99: 1788-1794). Results The patients with COPD differed from healthy controls in frequencies of MMP9 -1562C/T alleles (p=0.02) and genotypes (p=0.03). An association of -1562T allele with COPD in comparison with healthy controls (frequencies: 0.20 vs 0.10, respectively;OR=2.07, 95%CI=1.15-3.72) was observed using Fisher exact test as a statistical method. Conclusion The MMP9 -1562T allele seems to be associated with disease susceptibility in the Polish COPD patients.