Bianca Rovati

Dendritic cells and vascular endothelial growth factor in colorectal cancer: correlations with clinicobiological findings.

Objective: Dendritic cells (DC) are central to the development of immune system responses. In a cohort of 54 patients affected by colorectal cancer, we prospectively investigated the number of peripheral blood (PB) DC type 1 (DC1) and type 2 (DC2) and correlated their counts and functionality to the stage of the disease and to vascular endothelial growth factor (VEGF) levels. Results: At diagnosis, compared with healthy controls, patients presented reduced PBDC1 and PBDC2 numbers (p < 0.001). Moreover, in cancer patients, PBDC showed low levels of DC-associated antigens (HLA DR, p = 0.004; CD11c, p < 0.001; CD83, p = 0.01; CD86, p = 0.007 and Mannose receptor, p = 0.029), an upregulation of CXCR4 (p = 0.017) and a reduced T cell stimulation capability (p < 0.001). DC1 and DC2 loss was higher in stage D versus stage ABC patients (p = 0.003 and p = 0.002, respectively); surgery and chemotherapy appeared to attenuate a DC defect, although the restoration of normal PBDC levels is completed only at 6 and 12 months after diagnosis, respectively. In this series of patients, PBDC1 and PBDC2 numbers inversely correlated with VEGF serum levels (p < 0.001), suggesting a possible effect of this cytokine on DC compartment. In culture, the exposure of monocyte-derived DC to VEGF produced a dramatic alteration of DC differentiation by (1) induction of apoptosis, (2) alteration of DC immunophenotypic profile and (3) increased CXCR4 expression. Exposure to anti-VEGF blocking antibodies reversed VEGF inhibitory effects in all cases. Conclusions: These findings suggest that in colorectal cancer patients there is a numerical and functional impairment of PBDC compartment possibly related to the stage of the disease and to VEGF levels.

Lack of dendritic cell mobilization into the peripheral blood of cancer patients following standard- or high-dose chemotherapy plus granulocyte-colony stimulating factor

Background. Dendritic cells (DC), the most specialized antigen-presenting cells, can be detected in the peripheral blood (PB) and divided into two subsets of populations, DC1 and DC2, endowed with different functions. The aim of this study was to evaluate the effect on DC release and on their subsets of three regimens utilized to mobilize CD34+ cells into the PB in cancer patients and in normal CD34+ cell donors. Patients and methods. The mobilizing sequences were: standard-dose epirubicin+taxol+granulocyte-colony-stimulating factor (G-CSF; 15 patients with advanced breast cancer), high-dose cyclophosphamide (CTX)+G-CSF (10 patients with breast cancer patients and 7 with non-Hodgkins lymphoma, NHL), and G-CSF alone (5 normal donors of CD34+ cells for allogeneic transplantation). Comparative data were obtained from the steady-state PB of 20 healthy volunteers. For flow cytometric analysis, DC were gated as negative for specific lineage markers (CD3, CD11b, CD14, CD16, CD56, CD19, CD20, CD34) and positive for HLA-DR. The DC1 and DC2 subsets were defined as CD11c and CDw123 positive, respectively. Results. The percentages of DC at baseline and the time of CD34+ cell peak were: 0.48 and 0.51 for standard-dose chemotherapy (CT); 0.55 and 0.63 for breast cancer after high-dose CTX+G-CSF; 0.53 and 0.71 for NHL after high-dose CTX+G-CSF; and 0.51 and 0.54 for normal donors of CD34+ cells after G-CSF alone (all p=n.s.).Mean DC1/DC2 ratios in each study group at the time of CD34+ cell peak were 0.10, 0.12, and 0.18, respectively. Finally, in the group of healthy volunteers, the percentage of circulating DC was 0.95 and the mean DC1/DC2 ratio was 1.28. Conclusion. To our knowledge, this is the first report that demonstrates that both standard-dose or high-dose CT, when utilized together with G-CSF, do not induce DC mobilization into the PB, whereas a reversed DC1/DC2 ratio is observed. Furthermore, a lack of significant DC mobilization after G-CSF alone was also seen, in contrast to what was previously observed by others. These data should be taken in account when evaluating clinical correlations between DC number and CPC engraftment in both the transplantation setting, when monitoring the effects on the immune system of combinations of new drugs and/or cytokines, and when high numbers of DC are required for both experimental and clinical applications.

Immunological Effects of Bevacizumab-Based Treatment in Metastatic Colorectal Cancer

Objective: The efficacy of bevacizumab in metastatic colorectal cancer (mCRC) could be related not only to its well-known antiangiogenetic properties but also to a hypothetical effect on the immune system of the host. Methods: We enrolled mCRC patients treated with a bevacizumab-based first-line therapy. Lymphocyte and dendritic cell subsets were evaluated at baseline, 3rd and 6th cycle. The clinical efficacy was estimated as response rate and progression-free survival. Forty healthy subjects were used as reference. Results: Fifty-one patients were enrolled. In comparison with healthy subjects, they showed a decrease of T and B cell compartments. Bevacizumab ameliorated the impairment of lymphocyte subsets, especially for T cells. Responders showed a trend toward an increase of CD3 (p = 0.07) and CD4 (p = 0.05). Among patients with a progression-free survival >1 year, only CD19 (p = 0.033) and CD20 (p = 0.013) showed a significant increase. No baseline impairment and no significant modification of dendritic cells were found. Conclusion: Bevacizumab-based therapy is able to increase B and T cell compartments. The expansion of T lymphocytes could imply an amelioration of dendritic cell-presenting capacity. These effects correlate with a more favourable clinical outcome and could be taken into account in clinical protocols aimed at combining antiangiogenetic-therapy with immunotherapy in mCRC.

Darbepoetin alfa for the treatment of anemia associated with myelodysplastic syndromes: efficacy and quality of life.

To evaluate efficacy, safety, changes in biological features, and quality of life (QoL) in low-risk anemic patients with MDS treated with darbepoetin alfa (DPO), 41 patients received DPO 150 μg weekly for 24 weeks. The dose was increased to 300 μg weekly in non-responsive patients. During treatment, 10/17 (59%) transfusion-dependent (TD) and 13/23 (56%) transfusion-free (TF) patients responded. In TF patients, Hb increased from 9.2 ± 0.9 g/dL to 10.3 ± 1.4 g/dL by 24 weeks (p = 0.004). The mean response duration was 22 weeks (95% CI: 19.7–24.0) in TF patients compared with 15.1 weeks (95% CI: 13.3–17.5) in TD patients. Response to treatment was associated with increases in QoL. Decreases in the percentage of apoptotic progenitor cells (p = 0.007) and CD34+ cells (p = 0.005) were observed. These results confirm previous studies demonstrating the safety and efficacy of DPO in anemic patients with MDS. Biological changes and improvement in QoL were associated with response. Adequate dosing is to be determined.

Flow cytometric analysis of peripheral blood dendritic cells in patients with severe sepsis.

Dendritic cells (DC) play a key role in cell‐mediated immunity. We aimed to analyse the number and function of peripheral blood (PB) myeloid and plasmacytoid DC (mDC/pDC) in patients with severe sepsis.

An eight-colour flow cytometric method for the detection of reference values of lymphocyte subsets in selected healthy donors

Determination of immunoregulatory cells in peripheral blood is important in the management of disease or in the therapeutic approaches that involve alterations in lymphocyte subpopulations. The aims of the present study were (1) to develop a standard multiparametric flow cytometric method for phenotypic detection and enumeration of lymphocyte subsets so as to reduce the variability in both sample preparation methodology and flow cytometric operations; (2) to furnish reference values of lymphocytes by using a selected healthy population; and (3) to examine the influence of age and sex on the distribution of lymphocytes expressing surface markers. Eighty healthy donors were analysed, and ten-parameter, eight-colour analytical procedure was performed. We furnished a panel to detect and to enumerate lymphocyte subpopulations by a multiparametric flow cytometric method to set the reference values to a selected healthy population. These values showed statistically but not clinically significant differences in T lymphocyte subsets and natural killer cells. Furthermore, significant age-related correlations in T lymphocyte and natural killer cells were observed. Lastly, males and females in relation to age showed a significant different trend in T and B lymphocyte subsets. We confirmed that this study provides a rapid and accurate method for the detection and quantification of lymphocyte subsets that could be utilized in the clinical settings. The definition of reference values in the healthy selected population could be helpful also to better define the disease status and to evaluate the treatment efficacy during clinical trials.

Lymphocyte subpopulation and dendritic cell phenotyping during antineoplastic therapy in human solid tumors

Patients with cancer show variable levels of immunosuppression at the time of the presentation, and cytotoxic antineoplastic therapy is the primary contributor to the clinical immunodeficiency often observed during the course of the disease. In both hematological and solid tumors, this phenomenon is primarily related to the T-cell depletion associated with inhibition of dendritic cell ability to induce both primary and secondary T- and B-cell responses. Complete restoration of immunocompetence following antineoplastic therapy implicates the progressive recovery of various cell subpopulations, and it is a complex process that also depends on the type, the dose, the scheduling, and the associations of the employed drugs. In the era of target therapies, several antiangiogenic drugs are increasingly used in combination with standard chemotherapy in the treatment of advanced solid tumors. Their clinical efficacy has been recently related not only to the specific antiangiogenic properties but also to an indirect hypothetical effect on the host immune system. In the present work, we have reviewed the most recent information regarding (1) the capacity of standard antineoplastic therapy to induce and maintain an immunodeficiency in patients with solid tumors and (2) the influence of the antiangiogenic treatment in association with standard chemotherapy on lymphocyte and dendritic cell subsets and the possible resulting additional antitumor mechanism.

Chemotherapy-induced anemia in breast cancer patients treated with pegfilgrastim-supported dose-dense regimens

The primary use of recombinant granulocyte colony-stimulating factors has reduced the incidence of febrile neutropenia during dose-dense adjuvant/neoadjuvant chemotherapy programs for breast cancer. Otherwise, in this population, filgrastim seems to worse chemotherapy-induced anemia, especially when administered with prolonged schedules that induced leukocytosis. No exhaustive data are available about the effect of long-lasting formulation of filgrastim (pegfilgrastim) on hemoglobin levels. We retrospectively analyzed the data regarding hemoglobin level and leukocyte count of 38 breast cancer patients treated with dose-dense anthacycline and/or taxane-based chemotherapy with pegfilgrastim support, both in adjuvant and in neoadjuvant settings. Mean hemoglobin levels progressively decreased throughout the treatment (without correlation with both the schedule of chemotherapy and the patient’s age) but only two patients developed mild anemia. No significant correlation was found between the degree of leukocytosis and the hemoglobin decrease. These data suggest that pegfilgrastim, per se, doesn’t seem to worse chemotherapy-induced anemia. This fact may be at least in part explains by its “balanced” impact on hematopoietic recovery during dose-dense chemotherapy.

Effect of peg-filgrastim-supported dose-dense adjuvant chemotherapy on the peripheral blood leukocyte phenotype in breast cancer patients

The aim of this study was to evaluate the effect of dose-dense adjuvant chemotherapy regimens with peg-filgrastim support on the phenotype of peripheral blood leukocytes in breast cancer patients. We evaluated the leukocyte phenotype of 14 patients aged 46-67 years undergoing 4 courses of chemotherapy with either epirubucin/cyclophosphamide (n=7) or 5-fluorouracil/epirubucin/cyclophosphamide (n=7) followed by 4 courses of taxol supported by peg-filgrastim (6 mg) administered 72 h after each chemotherapy course. The overall leukocyte number significantly increased from the first treatment course, while total lymphocytes tended to decrease with a negative peak following the 6th course (p=0.03). B (CD19+, CD20+) and early B lymphocyte subsets (CD20+/CD38+) significantly decreased during treatment (p<0.05), while T lymphocyte subsets did not show significant changes, except a decrease in T helper (CD4+) cells. Immature T lymphocytes (CD4+/CD8+ subset), dendritic cells (CD11c+) and NK cells (CD56+) increased with respect to the baseline. Our results suggest that dose-dense chemotherapy programs with the support of peg-filgrastim did not significantly impair the immune system of breast cancer patients and allowed for a rapid restoration of most immune competent cells. These observations may have important clinical implications with a view to vaccination or other immunotherapeutic approaches to solid tumours.

Simultaneous detection of circulating immunological parameters and tumor biomarkers in early stage breast cancer patients during adjuvant chemotherapy.

BackgroundChemotherapy-induced immune suppression has mainly been studied in patients with advanced cancer, but the influence of chemotherapy on the immune system in early stage cancer patients has so far not been studied systematically. The aim of the present study was to monitor the immune system during anthracycline- and taxane-based adjuvant chemotherapy in early stage breast cancer patients, to assess the impact of circulating tumor cells on selected immune parameters and to reveal putative angiogenic effects of circulating endothelial cells.MethodsPeripheral blood samples from 20 early stage breast cancer patients were analyzed using a flow cytometric multi-color of antibodies to enumerate lymphocyte and dendritic cell subsets, as well as endothelial and tumor cells. An enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of various serological factors.ResultsDuring chemotherapy, all immunological parameters and angiogenesis surrogate biomarkers showed significant decreases. The numbers of circulating tumor cells showed significant inverse correlations with the numbers of T helper cells, a lymphocyte subset directly related to effective anti-tumor responses. Reduced T helper cell numbers may contribute to systemic immunosuppression and, as such, the activation of dormant tumor cells.ConclusionsFrom our results we conclude that adjuvant chemotherapy suppresses immune function in early stage breast cancer patients. In addition, we conclude that the presence of circulating tumor cells, defined as pan-cytokeratin+, CD326+, CD45− cells, may serve as an important indicator of a patient’s immune status. Further investigations are needed to firmly define circulating tumor cells as a predictor for the success of breast cancer adjuvant chemotherapy.