Dendritic cells in peripheral blood of patients with breast and lung cancer--a pilot study.

Dendritic cells (DCs) are regarded as the most potent antigen presenting cells that are well suited to activate T cells toward various antigens, such as tumor-associated antigens, due to their costimulatory activity. There is evidence that DCs are of diverse origin, with at least two types of myeloid and lymphoid precursors implicated in their generation. The recent reports demonstrated that the number and function of dendritic cells might change dramatically in cancer patients. In the present study we evaluated the percentage of myeloid and lymphoid DCs in patients with breast cancer, non-small cell lung cancer (NSCLC) and in the healthy donors. The percentage of both DC populations was significantly lower in patients with NSCLC than in the control group. In patients with breast cancer, the number of lymphoid DCs was significantly higher than in NSCLC patients. The obtained results suggest influence of pathological states on host immune system. The decrease in the number of DCs in the peripheral blood from cancer patients may be closely correlated with the type of tumour.