CD4+CD25+ Regulatory T cells and CD8+CD28- Suppressor Cells in Cancer Patients Older than Seventy Years

Objective: Immunosenescence is an important aspect in elderly cancer patients. In aging, T cell dysfunction and increasing CD4+CD25+ Regulatory T (Treg) cells have been reported. However, the status of these cells has not been uncovered so far in elderly cancer patients. In this study, we aimed to investigate Treg cells, CD8+CD28- suppressor cells, and other lymphocyte subpopulations in elderly cancer patients. Materials and Methods: Seventy-five cancer patients were included in the study. Data were obtained from our previous three studies about Treg, suppressive cells and other lymphocyte populations of breast, gastric and lung cancer patients. Total CD4+CD25+ Treg cells, CD8+CD28- suppressor cells, CD8+ memory cells, CD8+ naive cells, Natural Killer (NK) cells, CD8+ and CD4+ T cells had been investigated by flow cytometry. The parameters were compared between in patients over and under the age of seventy. Results: Eighteen patients were older than 70 years of age and fifty-seven patients were not. The percentage of CD4+CD25high cells in CD4+ T cells were higher in elderly cancer patients than control patients (smaller than 70 years old) (13.01%±6.59% vs. 8.43%±5.01%; p:0.02). CD8+CD28- suppressor cells in lymphocytes were similar in both groups (18.12%±7.73% vs 18.03%±8.33%; p:0.97). NK cells were elevated in elderly patients. CD8+ memory cells, CD8+ naive cells, CD8+ T cells, and CD4+ T cells were not different between groups. Conclusion: Our data suggest that CD4+CD25+ Treg cells are increased in elderly cancer patients, but not CD8+CD28- suppressor cells. This may be a cause of age-related immunosuppression in cancer patients.