Background

A reported imbalance of Th1 and Th2 may be responsible for the occurrence and progress of certain diseases. Patients with advanced cancer may have impaired cell-mediated immunity caused by a switch from Th1 to Th2. We investigated the balance of Th1 and Th2 in cancer patients using two approaches.

Methods

Flow cytometry was used to define Th1 and Th2 using intracellular cytokines, thereby determining the frequency of these helper T cells in CD4+ peripheral blood mononuclear cells (PBMC). The amount of cytokines secreted by stimulated PBMC in bulk culture was determined.

Results

Production of TNF-alpha and IFN-gamma in the culture was significantly lower in 9 patients (1188+/-634 pg/ml and 46+/-84 pg/ml) than in 10 healthy subjects (2491+/-1037 pg/ml and 295+/-219 pg/ml)(p< 0.002 and p< 0.003), while the production of IL-4 was slightly higher in cancer patients than in the healthy subjects. The percentage of IFN-gamma-IL-4+ cells in CD4+ cells was significantly higher in the patients than in healthy subjects (4.3+/-2.0% and 2.4+/-0.7%); there was no difference in IFN-gamma+ IL-4-cells between the two groups. The ratio of IFN-gamma+ IL-4-and IFN-gamma-IL-4+ cells per individual was significantly lower in the patients.

Conclusion

These results indicated that an imbalance of Th1 and Th2 was found not only in the frequency of the subsets in PBMC, but also in the capacity for cytokine-production.