Our study suggests significant correlations between both tCEC and rCEC baseline levels and the antitumor efficacy of a bevacizumab-based combination therapy in mCRC patients, thus confirming that these biomarkers could be used in the clinical setting as an early predictor of tumor response.

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.

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.

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 microg weekly for 24 weeks. The dose was increased to 300 microg 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.

Dendritic cells (DCs) are the key antigen-presenting cells controlling the initiation of the T cell- dependent immune response. Currently, two peripheral blood DC subsets have been identified on the basis of their CD11c expression. The CD11c-negative (CD11c–) DCs (expressing high levels of CD123) are designated as lymphoid-derived DCs (DC2), whereas the CD11c+/CD123– cells, do identify the myeloidderived DCs (DC1). A growing number of studies have been conducted in recent years on both the quantitative and functional alterations of DCs and their subsets in different pathological conditions. In the present study we assessed, using two different flow cytometric (FCM) techniques, the normal profile of blood DCs in 50 italian adult healthy subjects (M/F: 25/25, median age 42.5 years, range 20-65). The percentage and the absolute number of DCs and their subsets, were obtained starting from whole blood samples in two ways: 1) by calculating the number of DCs when gated as lineage-negative/ HLA-DR+ and identifing the two subsets as CD11c+ (DC1) and CD123+ (DC2) and 2) by using three specific markers: BDCA.1 (CD11c+ high/CD123+ low, myeloid DCs); BDCA.2 (CD11c-/ CD123+high, lymphoid DCs); BDCA.3 (CD11c+low /CD123–, myeloid DCs). Six parameters, 4-color FCM analysis were perfomed with a BD FACSCanto equipment. The mean values of the percentage and of the absolute number were: 0.5±0.2% and 30±11 cells/?L for DCs; 0.2±0.1% and 15±6 cells/?L for DC1; 0.2±0.1% and 15±7 cells/?L for DC2. The same values were: 0.2±0.1% and 16±7 cells/?L for BDCA.1; 0.2±0.1% and 12±7 cells/?L for BDCA.2; 0.02±0.01% and 2±1 cells/?L for BDCA.3, respectively. Our study confirmes that the two types of FCM analysis are able to identify the DC population. We also provides the first reference values on normal rates and counts of blood DCs in italian adult healthy subjects

Background: 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.Methods: Twenty-six septic patients, 20 surgical patients (abdominal aortic aneurysm) and 20 healthy controls were enrolled in this prospective study.Results: At day 1 (enrollment in the study), septic patients showed in comparison with healthy controls, decreased mDC (P < 0.001) and increased pDC (P 5 0.03), resulting in a reduction of the mDC/ pDC ratio (P < 0.001). Surgery induced a decrease in both mDCs and pDCs level, without modification of mDC/pDC ratio. Septic patients included 15 survivors and 11 nonsurvivors. At day 1 no significant difference was found in mDC between the two groups, while pDCs were significantly higher in nonsurvivors (P 5 0.03). At the outcome, mDC were selectively increased with respect to day 1 in survivors (P 5 0.001), while no significant differences were observed as far as pDC count is concerned in both groups. Sorted DC from septic patients showed in comparison with healthy controls, reduced levels of HLA DR (P < 0.001), CD11c (P < 0.001), CD83 (P 5 0.006) and of costimulatory molecule CD86 (P 5 0.003); an up-regulation of chemokine receptor CXCR4 (P 5 0.031) and increased apoptosis (P < 0.001).Conclusions: Sepsis has a profound effect on PB DC compartment. These alterations appear to be sepsisspecific. Increased apoptosis and alteration of migration and trafficking mechanism may be involved in DC compartment modification. DC alterations could contribute to sepsis-mediated immunoparalysis. V C 2010 International Clinical Cytometry Society

Summary:We have evaluated bone marrow morphology, percentage of bone marrow CD34 þ cells, proliferative activity of bone marrow precursors, clonogenic assay (BFU-E and CFU-GM) in short-term bone marrow cultures, and bone marrow cell apoptosis, together with serum TNF-a and IL-6, in 16 chronic, refractory RA patients, as well as in five healthy controls. Of 16 RA patients (68.7%), 11 showed a reduced bone marrow cellularity, while it was normal in all the controls. In RA patients, the median percentage of CD34 þ bone marrow cells, the median percentage of proliferating bone marrow myeloid precursors, and the median number of both BFU-E and CFU-GM colonies were significantly lower than observed in the controls. As far as TNF-a and IL-6 titers is concerned, the latter did not significantly differ from controls' values, while TNF-a titers were significantly lower in healthy controls. Finally, the median apoptotic index of early bone marrow myeloid cells of RA patients was significantly higher compared with controls. These observations may identify the biological risk factors for impaired mobilization and/or engraftment when RA patients are candidates for autologous hematopoietic stem cell grafting.

We confirmed the predictive role of an increase in CECs in mCRC patients treated with Bevacizumab-based therapy and showed that modifications in CECs and APO-CECs are independent factors. This underlines the relevance of a simultaneous quantitative and functional evaluation of these biomarkers in view of their possible diagnostic utility.