Immunological examination of peripheral blood in patients with colorectal cancer compared to healthy controls.

BACKGROUND: The objective of this study was to investigate serum levels of immunosuppressive cytokines TGF beta 1 and VEGF and count of immune cells in peripheral blood in stage II and III colorectal cancer patients.

METHODS: Blood samples were collected from 22 colorectal patients and 25 healthy controls before the start of treatment. All patients were examined by a clinical immunologist to exclude patients with immune disorders and autoimmune diseases. TGF beta 1 and VEGF were measured by ELISA, and anti-tumor cellular immunity cells (CD4, CD8, B cells, NK cells) were measured by flow cytometry.

RESULTS: TGF beta 1 and VEGF plasma levels were significantly increased in stage II and III colorectal patients compared with control group (both p < 0.0001). A decrease in the cellular immunity was shown in the absolute numbers of cytotoxic T lymphocytes (CD8+ ; p = 0.0240), helper T lymphocytes (CD4+ ; p = 0.0019), and natural killer cells (CD16 + CD56+; p < 0.0001) in both stage II and stage III patients. On the contrary, B lymphocyte (CD19+) serum levels were increased in colon cancer patients (p < 0.0001) compared to the control group.

CONCLUSIONS: Our results show peripheral blood levels of TGF beta and VEGF were significantly increased in colorectal patients and changes in cellular anticancer immunity in comparison to control group. These results will be compared with results from Immunoscore.