Maria Ciccone

Chronic lymphocytic leukemia with 6q- shows distinct hematological features and intermediate prognosis

Cytogenetic and fluorescence in situ hybridization studies were successfully performed in 217 chronic lymphocytic leukemia (CLL). In all, 13 patients with 6q21 deletion were identified and characterized in comparison with 92 patients with ‘favourable’ karyotype (normal or 13q−), 69 cases with ‘intermediate risk’ (1–2 anomalies) and 43 cases with ‘unfavourable’ karyotype (complex, 11q− or 17p−). Six out of 13 cases with 6q− showed an excess of atypical lymphocytes, a finding confirmed at the histologic level; >20% CD38+ cells were seen in 5/6 cases. IGVH mutational status revealed >98% homology to the germline sequence in 4/10 cases. When compared with the ‘favourable’ group, patients with 6q− showed a higher white blood cell (WBC) count, frequent splenomegaly, atypical morphology, CD38+ and short time from diagnosis to first treatment and short survival. A higher median WBC count was found in the 6q− group vs the intermediate-risk group; survival was shorter in the unfavourable group. To ascertain if the 6q− anomaly was an independent factor predicting for an inferior outcome among those patients with ‘favourable’ cytogenetics, we performed an analysis of prognostic factors in 105 patients (92 ‘favourable’ plus 13 with 6q−), showing that the 6q− chromosome maintained its prognostic significance at multivariate analysis (P=0.02) along with stage (P=0.01). We conclude that CLL with 6q− is characterized by a high incidence of atypical morphology, classical immunophenotype with CD38 positivity and intermediate incidence of IGVH somatic hypermutation. Clinicobiological features and outcome show that this cytogenetic subset of CLL should be allocated in an intermediate-risk category.

MicroRNAs involvement in fludarabine refractory chronic lymphocytic leukemia

BackgroundFludarabine, is one of the most active single agents in the treatment of chronic lymphocytic leukemia (CLL). Over time, however, virtually all CLL patients become fludarabine-refractory. To elucidate whether microRNAs are involved in the development of fludarabine resistance, we analyzed the expression of 723 human miRNAs before and 5-days after fludarabine mono-therapy in 17 CLL patients which were classified as responder or refractory to fludarabine treatment based on NCI criteria.ResultsBy comparing the expression profiles of these two groups of patients, we identified a microRNA signature able to distinguish refractory from sensitive CLLs. The expression of some microRNAs was also able to predict fludarabine resistance of 12 independent CLL patients. Among the identified microRNAs, miR-148a, miR-222 and miR-21 exhibited a significantly higher expression in non-responder patients either before and after fludarabine treatment. After performing messenger RNA expression profile of the same patients, the activation of p53-responsive genes was detected in fludarabine responsive cases only, therefore suggesting a possible mechanism linked to microRNA deregulation in non-responder patients. Importantly, inhibition of miR-21 and miR-222 by anti-miRNA oligonucleotides induced a significant increase in caspase activity in fludarabine-treated p53-mutant MEG-01 cells, suggesting that miR-21 and miR-222 up-regulation may be involved in the establishment of fludarabine resistance.ConclusionsThis is the first report that reveals the existence of a microRNA profile that differentiate refractory and sensitive CLLs, either before and after fludarabine mono-therapy. A p53 dysfunctional pathway emerged in refractory CLLs and could contribute in explaining the observed miRNA profile. Moreover, this work indicates that specific microRNAs can be used to predict fludarabine resistance and may potentially be used as therapeutic targets, therefore establishing an important starting point for future studies.

Immunophenotypic, cytogenetic and functional characterization of circulating endothelial cells in myelodysplastic syndromes.

Circulating endothelial cells (CECs) are associated with neoangiogenesis in various malignant disorders. Using flow cytometry, we studied CECs in 128 patients with myelodysplastic syndrome (MDS). MDS patients had higher CEC levels than controls (P<0.001), and an inverse relationship was found between CECs and international prognostic scoring system risk (r=−0.55, P<0.001). There was a positive correlation between marrow microvessel density and CECs, low-risk patients showing the strongest association (r=0.62, P<0.001). We calculated a progenitor-to-mature CEC ratio, which was higher in MDS patients than in healthy subjects (P<0.001), the highest values were found at diagnosis. CECs assessed by flow cytometry positively correlated with the ability to produce endothelial colony-forming cells in vitro (ECFCs; r=0.57, P=0.021), which was significantly higher in MDS patients than in controls (P=0.011). Fluorescence in situ hybridization analysis showed that a variable proportion of CECs (from 40 to 84%) carried the same chromosomal aberration as the neoplastic clone, while endothelial cells isolated from in vitro assays were negative. This study suggests that CECs reflect the abnormal angiogenesis found in MDS, especially in the early stages of the disease. The increased number of functional endothelial progenitor cells in MDS strengthens the rationale for therapeutic interventions aimed at restoring a normal interaction between hematopoietic progenitors and marrow microenvironment.

Soluble urokinase-type plasminogen activator receptor (suPAR) as an independent factor predicting worse prognosis and extra-bone marrow involvement in multiple myeloma patients

Summary. The urokinase‐type plasminogen activator (uPA) system, which consists of a proteinase (uPA), a receptor (uPAR or CD87) and inhibitors, is involved in proteolysis, cell migration, tissue remodelling, angiogenesis and cell adhesion. Recent findings suggest that malignant plasma cells express uPA and uPAR. The expression of these factors could represent a process by which myeloma plasma cells interact with the bone marrow (BM) environment and influence important biological events such as bone matrix degradation, plasma cell invasion and homing and, possibly, clinical evolution. We evaluated uPAR (CD87) and its soluble form (suPAR) in 49 multiple myeloma (MM) patients and correlated their expression and levels with clinico‐biological characteristics of the disease. Flow cytometric analysis demonstrated that CD87 was expressed in all MM patients. High CD87 expression was associated with higher intensity of expression of CD56 (P = 0·038), CD38 (P = 0·058) and CD138 (P = 0·054) and CD45bright positivity (P = 0·014). suPAR levels correlated positively with soluble serum CD138 (P = 0·001), creatinine (P = 0·001), beta2‐microglobulin (P < 0·001), disease stage (P = 0·017) and extra‐BM involvement (P = 0·002). In the 46 evaluable patients, multivariate analysis showed that high levels of suPAR (P = 0·0214) and disease stage (P = 0·0064) were predictive of extra‐BM involvement. In multivariate Cox analysis, 13q deletion (P = 0·0278), high soluble serum CD138 (P = 0·0201) and high suPAR (P = 0·0229) were the only parameters that independently affected survival. We conclude that CD87 is expressed on myeloma plasma cells and that suPAR, which predicts extra‐BM involvement and poor prognosis, possibly represents a molecule with a relevant role in the biology of MM.

Flow cytometric detection of accelerated telomere shortening in myelodysplastic syndromes : correlations with aetiological and clinical-biological findings

Abstract:  Using quantitative fluorescence in situ hybridisation and flow cytometry (flow‐FISH), we investigated the biological and clinical relevance of telomere length in 55 patients affected by myelodysplastic syndromes (MDS) compared with 55 sex‐ and age‐matched controls. We found that telomere fluorescence in MDS granulocytes, and CD34+ cells did not decline with age as in normal controls and that MDS granulocytes and CD34+ cells had significantly shorter telomeres than healthy controls. A significant higher incidence of cases with intermediate‐unfavourable cytogenetics and International Prognostic Scoring System (IPSS) int‐2/high‐risk group was observed among patients with lower telomere fluorescence. We also found that apoptosis in CD34+ cells was significantly higher in IPSS int‐1 low‐risk patients when compared with IPSS int‐2 high‐risk cases and healthy controls and that CD34+ cell telomere fluorescence directly correlated with CD34+ cell apoptosis. Reduced telomere fluorescence was associated with a history of occupational exposure to toxic agents and with worse survival in univariate and multivariate analyses. Our results suggest that flow‐cytometry assessment of telomere dynamics may represent a valuable tool in the biological and clinical–prognostic characterisation of MDS disorders.

rHuEpo administration in patients with low-risk myelodysplastic syndromes: evaluation of erythroid precursors' response by fluorescence in situ hybridization on May-Grunwald-Giemsa-stained bone marrow samples

Summary. The issue of whether, in patients affected by myelodysplastic syndromes (MDS), haematological response to cytokines, particularly to recombinant human erythropoietin (rHuEpo), is a phenomenon related to the stimulation of normal haemopoietic cells or to the differentiation of cells belonging to the abnormal clone remains an open question. To assess the pattern of response to rHuEpo treatment of bone marrow (BM) cells, we evaluated in 13 low‐risk MDS patients with known cytogenetic abnormalities the number of cytogenetically normal and abnormal cells by conventional cytogenetic analysis (CCA) and by a fluorescence in situ hybridization (FISH) technique, enabling the simultaneous visualization of FISH chromosomal abnormalities in morphologically and immunophenotypically identifiable BM elements. Patients responding to rHuEpo presented a lower number of abnormal metaphases at diagnosis in comparison with patients who did not respond (22·74%vs 76·23%, P = < 0·001). This was confirmed by the combined morphological FISH analysis, showing that, before treatment, BM samples from patients responding to rHuEpo had a lower proportion of both FISH abnormal erythroid (36·48%vs 66·93%, P = 0·002) and myeloid (40·76%vs 67·70%, P = 0·014) elements than unresponsive patients. After rHuEpo treatment, responding patients presented a significantly lower proportion of FISH abnormal erythroid precursors than observed before treatment (16·93%vs 36·48%, P = 0·017). Likewise, in responding patients, a significantly lower proportion of FISH abnormal erythroid elements (16·93%vs 66·30%, P < 0·001) was detected in comparison with unresponsive patients. These findings provide evidence that, in low‐risk MDS patients with known cytogenetic abnormalities, response to rHuEpo may be due to the proliferation of karyotypically normal erythroid precursors, possibly representing residual normal erythroid elements.

Proliferation centers in chronic lymphocytic leukemia: correlation with cytogenetic and clinicobiological features in consecutive patients analyzed on tissue microarrays.

To better define the significance of proliferation centers (PCs), the morphological hallmark of chronic lymphocytic leukemia (CLL), lymph node biopsies taken from 183 patients were submitted to histopathologic and fluorescence in situ hybridization (FISH) studies using a 5-probe panel on tissue microarrays. Seventy-five cases (40.9%) with confluent PCs were classified as ‘PCs-rich’ and 108 cases (59.1%) with scattered PCs were classified as ‘typical’. Complete FISH data were obtained in 101 cases (55.1%), 79 of which (78.2%) displayed at least one chromosomal aberration. The incidence of each aberration was: 13q- 36,7%, 14q32 translocations 30.8%, 11q- 24.7%, trisomy 12 19.5% and 17p- 15.6%. Five cases showed extra copies of the 14q32 region. The ‘PCs-rich’ group was associated with 17p-, 14q32/IgH translocation, +12, Ki-67>30%. The median survival from the time of tissue biopsy for PCs-rich and typical groups was 11 and 64 months, respectively (P=0.00001). The PCs-rich pattern was the only predictive factor of an inferior survival at multivariate analysis (P=0.022). These findings establish an association between cytogenetic profile and the amount of PC in CLL, and show that this histopathologic characteristic is of value for risk assessment in patients with clinically significant adenopathy.

Circulating endothelial cells in patients with chronic lymphocytic leukemia: clinical-prognostic and biologic significance.

In patients with cancer, circulating endothelial cells (CECs) are increased and are correlated with an aggressive disease course. However, the clinical and biologic significance of CECs in chronic lymphocytic leukemia (CLL) remains uncertain.

Dendritic cell recovery after allogeneic stem-cell transplantation in acute leukemia: correlations with clinical and transplant characteristics

We have analyzed the kinetics of reconstitution of circulating dendritic cell (DC) subsets (myeloid‐DC1 and lymphoid‐DC2) in 19 patients affected by acute leukemia undergoing allogeneic hematopoietic stem‐cell transplantation (HSCT). We have found that pretransplant DC1 and DC2 were lower in leukemic patients than in healthy subjects (P = 0.003 and P = 0.004, respectively) and that the number of DC2 (but not DC1) infused with the graft was higher in patients receiving peripheral blood stem cells (PBSC) (P = 0.03). Patients recovered to the pretransplant DC1 and DC2 levels within day +60; however, a normal DC1 number was reached on day +365, while DC2 remained lower than in controls up to 1 yr after transplant. DC1 reconstitution did not differ significantly between patients receiving bone marrow stem cells (BMSC) or PBSC, while patients receiving PBSC presented increased levels of DC2 on day +30 (P = 0.008) and +100 (P = 0.047) and a higher number of T lymphocytes and natural killer cells until day +365. The occurrence of graft vs. host disease (GVHD) was not influenced in our cases by DC1/DC2 graft composition, but patients with acute GVHD when compared with patients without acute GVHD presented a significantly less rapid DC recovery (DC1 P = 0.03, DC2 P = 0.009 on day +30, and DC1 P = 0.012, DC2 P = 0.006 on day +100). At the moment of relapse, a decrease of DC1/DC2 numbers was observed in four patients and the presence of two different DC populations one with a normal karyotype, and the other with the same cytogenetic abnormality as the malignant clone was detected by fluorescence in situ hybridization analysis. In conclusion, these observations suggest that in allogeneic HSCT recipients, DC recovery is a slow process possibly contributing to the high risk of infections in the post‐transplant period and is possibly influenced by the source of HSC, the occurrence of GVHD and relapse. Further studies are warranted to investigate the significance of DC reconstitution in the transplant setting.

Mobilization of endothelial progenitor cells in patients with hematological malignancies after treatment with filgrastim and chemotherapy for autologous transplantation.

In recent years, endothelial progenitor cells (EPCs), gave rise to increasing interest because of their possible use as a therapeutic tool in the treatment of vascular lesions in ischemic tissues or as a target for anti neoplastic therapy. It has been shown that several drugs can increase the number of EPCs into the peripheral blood (PB). However, there is insufficient data concerning the mobilization and collection of EPCs during CD34+ cell mobilization. In this study, we have evaluated EPC mobilization and collection in a series of 47 patients affected by lymphoid neoplasms [31 non Hodgkin lymphoma and 16 multiple myeloma] undergoing CD34+ cell mobilization with cyclophosphamide (4000 mg/m2) and Filgrastim (5 μg/kg). PB EPCs identified by flow cytometry as CD34+/VEGFR2+/CD133+ cells showed a peak on day +10. This peak paralleled that of PB CD34+/CD45+ cells. A direct correlation was observed between CD34+ and CD34+/VEGFR2+/CD133+ cells (r = 0.99 P < 0.0001). An average of 23.7 × 10e6 CD34+/VEGFR2+CD133+ cells have been collected (range 12.1–41.76 × 10e6). These findings showed that in hematological diseases, cyclophosphamide in combination with filgrastim allows the mobilization and collection of large numbers of EPCs which may be used for reparative medicine studies in these patients.