Background/aims: Depression of cell-mediated immunity frequently accompanies solid tumor malignancy, and appears to be worsened as the disease progresses. In this study, we investigated cell-mediated immune status in colorectal cancer patients.
Methodology: Interleukin-2 (IL-2) productivity by phytohemagglutinin (PHA)-stimulated non-adherent peripheral blood mononuclear cells (PBMC), and prostaglandin E2 (PGE2) productivity by LPS-stimulated adherent PBMC were investigated in colorectal cancer patients with hepatic metastasis (n=20) and without hepatic metastasis (n=20), and in non-malignant disease controls (n=20). Percentages of peripheral blood T-cell subsets and NK activity were also investigated.
Results: In the colorectal cancer patients with hepatic metastasis IL-2 productivity was significantly decreased, compared with the controls. However, the percentages of T-cell subsets and NK activity were not significantly different among the groups. Meanwhile, PGE2 productivity in the patients with hepatic metastasis was significantly increased, compared with the other groups, and was significantly correlated with the hepatic tumor load.
Conclusions: Tumor-bearing state, especially metastasis to the liver, may influence immune status of the patient. For evaluating cellular immunity status, cytokine productivity by activated lymphocytes and monocytes may be a more sensitive marker rather than other conventional immunological parameters, and may also provide useful information for immune intervention in the treatment of patients from this point of view.