Impaired and imbalanced cellular immunological status assessed in advanced cancer patients and restoration of the T cell immune status by adoptive T-cell immunotherapy.

Recent progress has been made in understanding the mechanisms of antitumor immune responses, which may further clarify the immune status of cancer patients. In this study, we performed a detailed evaluation of the immunological status of 47 patients with advanced solid cancer, who had received no immunosuppressive treatment, and compared the results with 32 healthy subjects. Flow-cytometry data for peripheral blood were obtained using 19 monoclonal antibodies against various cell surface and intracellular molecules. Absolute numbers of T cells, several T cell subsets, B cells, and NK cells were significantly decreased in patients compared with healthy subjects. The percentage of CD27(+)CD45RA(+) T cells was lower and that of CD27(-)CD45RA(-) T cells was higher in patients compared with controls. Regulatory and type 2 helper T cells were elevated in patients relative to healthy subjects. The percentage of perforin(+) NK cells was significantly lower in patients than in controls. These results suggest a dysfunctional anti-tumor immune response in cancer patients. Furthermore, peripheral blood from 26 of 47 cancer patients was analyzed after adoptive T cell immunotherapy (ATI). ATI increased the number of T cell subsets, but not B and NK cells. The number and percentage of regulatory T cells decreased significantly. These results suggest that ATI can restore impaired and imbalanced T cell immune status.