Differences in systemic inflammation between cigarette and biomass smoke-induced COPD

It is known that biomarkers of systemic inflammation are raised in COPD caused by tobacco (T-COPD) compared with healthy controls, but there is less information on the inflammatory status of subjects with COPD caused by biomass smoke (B-COPD). In addition, the possible (if any) differences in inflammation between both types of the disease are still not well known. The aim of this study was to assess the inflammatory profile in B-COPD and T-COPD.

A total of 20 subjects (15 men and five women) with T-COPD were matched one to one for sex, age and forced expiratory volume in 1 s (FEV₁) to 20 B-COPD patients. In all, 20 sex-matched healthy subjects with normal lung function without smoking history or biomass exposure were included as controls. The following biomarkers were measured: exhaled nitric oxide, serum IL-6, IL-8, IL-5, IL-13, periostin, surfactant protein-P, TNF-α, IgE, erythrocyte sedimentation rate, C-reactive protein and fibrinogen. Complete blood count was also obtained.

The age of the subjects was 70.2±7.9 years and FEV₁% was 56.2%±14.6%. Most inflammatory biomarkers were higher in both types of COPD than in healthy controls. IL-6, IL-8 and IL-5 were significantly higher in T-COPD than in B-COPD, without other significant differences.

Both types of COPD are associated with high levels of systemic inflammation biomarkers. T-COPD patients have a higher systemic inflammatory status than the patients with B-COPD.