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.

Evaluation of the Abbott AxSYM cytomegalovirus (CMV) immunoglobulin M (IgM) assay in conjunction with other CMV IgM tests and a CMV IgG avidity assay.

The measurement of the avidity of cytomegalovirus (CMV) immunoglobulin G (IgG) antibodies has been shown by several investigators to be useful in identifying and excluding primary CMV infections in pregnant women. In this work, we examined the diagnostic utility of reflex testing of CMV IgM-positive specimens from pregnant women by using a CMV IgG avidity assay. The utility of this approach was directly dependent on the sensitivity of the CMV IgM assay employed during the initial screen. The higher initial reactivity rate of the AxSYM CMV IgM assay was necessary in order to detect CMV IgM in specimens containing low-avidity CMV IgG antibodies, indicative of a primary CMV infection, which other CMV IgM assays (Behring, Vidas, Captia, and Eurogenetics) fail to detect in some cases. The use of the AxSYM CMV IgM assay, followed by an avidity test, should result in more accurate diagnosis of CMV infection in pregnant women.

Lymphocytosis decline is not responsible for tumor progression in cancer patients chronically treated with interleukin-2.

AIMS AND BACKGROUND: The antitumor activity of IL-2 is mediated by an increase in lymphocyte number. Moreover, our previous studies have shown that therapy for 1 week/month with low-dose subcutaneous IL-2 is sufficient to maintain high levels of lymphocytes in cancer patient who have had tumor regression or stable disease (SD) in response to IL-2 immunotherapeutic cycles. This study was performed to establish whether tumor progression in cancer patients chronically treated with IL-2 may be associated with lymphocyte number decline. METHODS: The study included 53 metastatic renal cell cancer patients, who were treated with 2 induction cycles of IL-2 subcutaneous immunotherapy (6 million IU/day for 5 days/week for 6 weeks, corresponding to one cycle). Tumor regression occurred in 15/53 patients, 20 patients had a SD, and the remaining 18 cases progressed. Non progressed patients (n = 35) underwent a maintenance therapy consisting of one week of therapy every month. After a median follow-up of 18 months, 26/35 patients with response or SD had progressed. The immune investigation consisted of lymphocyte, T lymphocyte, NK cell number determination and sCD25 level detection. RESULTS: The mean number of lymphocytes, T lymphocytes and NK cells observed on IL-2 maintenance therapy was significantly higher than that seen before beginning the immunotherapy. Moreover, mean number of lymphocytes and mean levels of sCD25 observed at the time of tumor progression were respectively lower and higher than those seen on maintenance therapy in the same patients, without, however, significant differences. CONCLUSION: Despite the importance of lymphocytes in mediating the antitumor activity of IL-2, this study shows that tumor progression in cancer patients chronically treated with low-dose IL-2 after response or SD during IL-2 induction cycles is not associated with a significant decline in lymphocyte, T lymphocyte or NK cell numbers. Further studies, carried out to analyze the functional status of immune cells at the time of tumor progression, will be necessary to define the role of immunity in cancer patients progressing under IL-2 chronic therapy.

Immunotherapy with low-dose subcutaneous interleukin-2 plus beta-interferon as a second-line therapy for metastatic colorectal carcinoma.

AIMS AND BACKGROUND: Beta-interferon (beta-IFN) has been proven to influence some IL-2-induced immune effects. On the basis of these experimental data, we evaluated the immunobiologic effects of an association between very low-dose IL-2 and beta-IFN in advanced cancer patients. METHODS: The study was performed in 15 metastatic colon cancer patients, who progressed in response to a first-line chemotherapy with 5-FU plus folates. IL-2 was given subcutaneously at a daily dose of 3 million IU in the evening for 6 days/week for 4 weeks. beta-IFN was injected subcutaneously at a dose of 3 million U/day for 7 days before the first IL-2 injection, then thrice/week until the end of IL-2 administration. In nonprogressed patients, a second cycle was given after a 14-day rest period. RESULTS: No objective tumor regression was seen. Stable disease was obtained only in 2/15 patients; the other 13 progressed. Toxicity was low in all cases. Natural killer cell and T-activated lymphocyte mean number significantly increased during the immunotherapy. Lymphocyte and eosinophil mean number also increased, without, however, significant differences. IL-2-induced suppressive events, consisting of an increase in T-suppressor cell number, and soluble IL-2 receptor levels were not blocked by beta-IFN. CONCLUSIONS: The study showed that the concomitant administration of beta-IFN may determine an improvement in the immune performance in metastatic cancer patients treated with very low-dose IL-2, even though this biologic improvement does not seem to be associated to a control of tumor development. Further studies in patients with less advanced disease are needed to better define the impact of the immune improvement induced by low-dose IL-2 plus beta-IFN on the clinical course of the neoplastic disease.