BACKGROUNDTo investigate the ability of alveolar macrophage (AM) and peripheral blood monocyte (PBMC) from lung cancer patients to produce Interleukin-10 (IL-10) and to evaluate the local and general cellular immune state of lung cancer patients.

METHODSAM and PBMC were obtained from 57 patients with lung cancer, 33 patients with benign pulmonary diseases and 12 healthy volunteers. IL-10 in the culture supernatants was measured quantitatively by ELISA.

RESULTS(1) Elevated levels of IL-10 produced by PBMC were found in lung cancer group with respect to healthy volunteers and patients with benign pulmonary diseases (148.60±35.56 vs 93.83±9.22 and 108.91±15.95 ng×L⁻¹ respectively) (P < 0.001). The level of IL-10 by AM from lung cancer patients was 132.06±30.42 ng×L⁻¹, which was remarkably higher than that of healthy volunteers (92.67±11.22 ng×L⁻¹) and benign pulmonary diseases (94.39±10.04 ng×L⁻¹) (P < 0.001). (2) The level of IL-10 produced by PBMC from lung cancer group of stage IV was significantly higher than that of stage I+II (178.33±13.52 vs 131.57±25.35 ng×L⁻¹) (P < 0.001). AM from lung cancer patients of stage III and IV produced more IL-10 than that of stage I+II did (150.13±15.57 and 160.50± 18.75 vs 117.05±28.12 ng×L⁻¹ respectively) (P < 0.001); PBMC from small cell lung cancer patients produced higher level of IL-10 than squamous cell carcinoma and adenocarcinoma did (194.83±23.88 vs 140.37± 27.00 ng×L⁻¹ and 136.50±27.39 ng×L⁻¹ respectively) (P < 0.01). AM from small cell lung cancer patients produced higher levels of IL-10 than squamous cell carcinoma and adenocarcinoma did (165.33±23.78 vs 127.74±26.19 ng×L⁻¹ and 120.30±29.66 ng×L⁻¹ respectively) (P < 0.01); Size of mass and performance status greatly affected the level of IL-10; IL-10 level of lung cancer patients with survival time more than 2 years was remarkably lower than that of patients with survival time less than 2 years (P < 0.01).

CONCLUSIONSHigher level of IL-10 presents both in local and general body of lung cancer patients. IL-10 may play an important role in deterioration of lung cancer. Detection of IL-10 level may be helpful to evaluate cellular immunity and predict prognosis of lung cancer patients.