Stromelysin-1 polymorphism as a new potential risk factor in progression of chronic obstructive pulmonary disease

Background. Chronic obstructive lung disease (COPD) is characterised by partially reversible usually progressive airflow limitation caused by inflammation and remodelling. Stromelysin-1 (MMP-3) has regulatory activity on other matrix-metalloproteinases. Altered MMP-3 activity has been described in different diseases. We investigated the role of a promoter MMP-3 polymorphism in determining susceptibility and severity of COPD. Methods. We studied 147 patients with COPD in stable conditions and distinguished two groups based on FEV1 values. In 100 patients functional modifications across a two-year period were noted. 133 healthy subjects were used as controls. Genotyping for the –1171 5A/6A MMP-3 polymorphism was performed using nucleotide sequencing. Results. No difference was noted in the genotype distribution between COPD patients and controls. However, among patients with severe disease 6A/6A genotype and 6A allelic frequency were significantly more represented than among mild-moderate patients (p < 0.05). The 6A/6A genotype was also associated with a higher FEV1 decline over time. Conclusions. Our data suggests that –1171 6A allele does not represent a risk factor for the development of COPD while it is associated with more severe disease and different functional decline. We hypothesise that a disregulation of MMP-3, possibly caused by the –1171 5A/6A polymorphism or other linked variants, may lead to different progression in COPD.