Inflammatory and immunological profiles in patients with COPD: relationship with FEV (1) reversibility

OBJECTIVE: To determine whether COPD severity correlates with sputum cell counts, atopy, and asthma. METHODS: This was a cross-sectional study involving 37 patients with COPD and 22 healthy subjects with normal lung function (controls). Sputum cell counts were determined by microscopy after centrifugation of samples. Skin prick tests were performed, and serum cytokines were determined by ELISA. RESULTS: Patients were stratified by bronchodilator response: a non-reversible airflow limitation ((non)RAL) group comprised 24 patients showing no significant post-bronchodilator change in FEV(1); and a partially reversible airflow limitation ((partial)RAL) group comprised 13 patients showing FEV(1) reversibility (post-bronchodilator FEV(1) increase ≥ 12%). The proportion of eosinophils in sputum was higher in the (partial)RAL group than in the (non)RAL group (p < 0.01), and there was an inverse correlation between the proportion of eosinophils and FEV(1) (p < 0.05). However, none of the patients had a history of asthma and skin prick test results did not differ between the two groups. In the patient sputum samples, neutrophils predominated. Serum levels of TNF, IL-6, IL-8, and RANTES (CCL5) were higher in patients than in controls (p < 0.001) but did not differ between the two patient groups. CONCLUSIONS: COPD patients with partial FEV(1) reversibility appear to have higher sputum eosinophil counts and greater airway hyperresponsiveness than do those with no FEV(1) reversibility. However, we found that COPD severity did not correlate with atopy or with the cytokine profile.