The level of damage to DNA in peripheral blood mononuclear cells.

<p>a) Evaluation by comet assay. b) Tail migration/cell length ratio measured with Comet Assay IV. c) Tail length/cell length ratio measured with Comet Assay IV. The study groups are designated as follows: (1) non-smoking, non-obstructive control individuals (n = 7); (2) non-obstructive smokers (n = 4); (3) patients with mild chronic obstructive pulmonary disease (COPD) (n = 3); (4) patients with moderate COPD (n = 7); (5) patients with severe COPD (n = 5); (6) patients with very severe COPD (n = 4); (7) patients with COPD exacerbation requiring hospitalisation (n = 6). Presented as mean ± SEM.