T-helper/T-regulator lymphocyte ratio as a new immunobiological index to quantify the anticancer immune status in cancer patients.

BACKGROUND The evaluation of the immune status of cancer patients is not routinely included in clinical oncological practice mainly because of the great number of candidate immune parameters that could potentially be the best index of the status of anticancer immunity. Until recently, the T-helper/T-suppressor lymphocyte ratio (CD4/CD8) was considered to be an index of immunosuppression in cancer patients. Successive studies documented the existence of several subtypes of CD4+ lymphocytes, as well as showing that CD8+ cells were not in fact suppressive, but cytotoxic lymphocytes. More recently, the existence of a subtype of T-helper lymphocytes has been demonstrated provided by an evident suppressive activity on anticancer immunity. These are the so-called T-regulator (T-reg) lymphocytes, which may be detected as CD4+CD25+ cells. MATERIALS AND METHODS A study was carried out to evaluate CD4+/CD4+CD25+ ratio, corresponding to the T-helper/T-reg cell ratio (TH/TR), in a group of 50 cancer patients in relation to their disease extension and in 20 healthy controls. RESULTS The mean TH/TR ratio observed in patients with metasytases was significantly lower with respect to that found in both patients without metastases and controls. On the contrary, the absolute mean number of T-reg cells was higher in patients with metastases than in those without, but the difference was not statistically significant. CONCLUSION The evaluation of T-reg cells in terms of their proportion with respect to T-helper cell total number seems to be more appropriate than the simple measurement of their absolute count, in order to quantify cancer-related immunosuppression. Thus, the TH/TR ratio could represent a useful biological marker to explore the immune status of cancer patients.