Increase of circulating B7-H4-expressing CD68+ macrophage correlated with clinical stage of lung carcinomas.

Tumor-associated macrophages (TAM) influence diverse processes such as angiogenesis, tumor cell proliferation, and metastasis during tumor progression. In a variety of tumor types, the amount of TAM has been associated with prognosis, but their role in lung cancer has not been fully elucidated. The purpose of this study was to investigate the B7-H4-expressing TAM in a series of 56 cases of lung carcinoma. In peripheral blood, B7-H4-expressing macrophage (CD68(+) cells) was compared among patients with lung cancer, patients with tuberculosis, and healthy donors. B7-H4-expressing macrophage in peripheral blood from lung cancer patients was significantly higher than that from healthy donors and tuberculosis patients. B7-H4-expressing macrophage was thereafter related to tumor size, lymph node metastasis and TNM stage. On the basis of the data obtained from literature, it is suggestd that lung carcinomas increase B7-H4-expressing macrophages, which might favor tumor progression.