ObjectiveTo monitor the airway inflammatory factors in exhaled breath condensate(EBC) of severe stable COPD patients during salmeterol/fluticasone (50/500μg, bid) treatment, and explore their clinical significance. MethodsTwenty-four sever stable COPD patients and 18 healthy controls were included in the study. EBC was collected from COPD patients before treatment (day 0) and 14 days, 28 days, 90 days after treatment. Meanwhile lung function test and SGRQ score were measured.Concentrations of IL-6 and IL-10 were measured by liquid chip and 8-isoprostane by enzyme-linked immunosorbent assay. ResultsLevels of 8-isoprostane, IL-6 and IL-10 in EBC were significantly higher in the sever stable COPD patients before treatment compared with the healthy controls. 8-isoprostane was decreased significantly at day 14 compared with day 0[(11.59±4.12) pg/mL vs. (14.17±4.66) pg/mL, P < 0.05], and kept in low level till day 90 (P > 0.05). IL-6 was significantly decreased at day 28 compared with day 0[(1.46±0.19) pg/mL vs. (1.59±0.19) pg/mL, P < 0.05], but did not change significantly till day 90. IL-10 was in low level but showed increase at day 90 compared with day 28[(1.72±0.19) pg/mL vs. (1.62±0.12) pg/mL, P < 0.05]. FEV1 and FEV1/FVC were improved and SGRQ score was decreased after 90 days treatment (P < 0.05). FEV1 was not correlated with 8-isoprostane, IL-6 or IL-10 level. ConclusionsDynamic observation of EBC 8-isoprostane level in severe COPD patients can help in evaluating drug efficacy. IL-10 may play a role in airway anti-inflammation.