[Antitumorigenic immunocompetence of alveolar macrophages in patients with lung cancer]

The antitumorigenic immunocompetence of alveolar macrophages(AMs) in patients with lung cancer was investigated.

Twenty-two patients with lung cancer and 18 control subjects underwent bronchoalveolar lavage (BAL) by fiberoptic bronchoscopy to collect BAL fluid (BALF). AMs in the BALF isolated by adherence on plate surface were incubated for 24 hours at 5% CO2, 37 degrees C in medium with or without granunocyte-macrophage colony stimulating factor (GM-CSF). The cell free supernatants (SP) and AMs were harvested, respectively, the activities of nitric oxide (NO), tumor necrosis factor-alpha (TNF-alpha), superoxide dismutase (SOD), and soluble interleukin 2 receptor in BALF and SP were examined by copper plating cadmium reduction, radioimmunoassay, xanthine-oxidase assay, and ELISA, respectively. mRNA expression of inducible nitric oxide synthase in AMs was detected by reverse transcription-polymerase chain reaction(RT-PCR).

(1) The activity of NO was lower in BALF of the tumor-bearing lungs than that of the nontumor-bearing lungs and control groups; the activities of TNF alpha, SOD, and sIL-2R were not statistically significant in BALF between patients with lung cancer and control groups. (2) In supernatants, the activities of NO and TNF alpha were lower in the tumor-bearing lungs than in nontumor-bearing lungs and control groups; sIL-2R concentration of the lung cancers was higher than that of control groups. (3) After AMs were stimulated by GM-CSF, the activities of NO, TNF alpha, and SOD were increased and that of sIL-2R was decreased in SP. (4) mRNA expression of iNOS was demonstrated in AMs of both groups. However, in comparison with beta-actin, the intensity of mRNA expression of iNOS in AMs of lung cancer patients was lower than that of control groups.

There are some deficiencies in the function of AM at the region of tumors and antitumorigenic immunocompetence in the patients with lung cancer.