Lilla Cro

Gene expression profiling of plasma cell dyscrasias reveals molecular patterns associated with distinct IGH translocations in multiple myeloma.

Multiple myeloma (MM) is the most common form of plasma cell dyscrasia, characterized by a marked heterogeneity of genetic lesions and clinical course. It may develop from a premalignant condition (monoclonal gammopathy of undetermined significance, MGUS) or progress from intramedullary to extramedullary forms (plasma cell leukemia, PCL). To provide insights into the molecular characterization of plasma cell dyscrasias and to investigate the contribution of specific genetic lesions to the biological and clinical heterogeneity of MM, we analysed the gene expression profiles of plasma cells isolated from seven MGUS, 39 MM and six PCL patients by means of DNA microarrays. MMs resulted highly heterogeneous at transcriptional level, whereas the differential expression of genes mainly involved in DNA metabolism and proliferation distinguished MGUS from PCLs and the majority of MM cases. The clustering of MM patients was mainly driven by the presence of the most recurrent translocations involving the immunoglobulin heavy-chain locus. Distinct gene expression patterns have been found to be associated with different lesions: the overexpression of CCND2 and genes involved in cell adhesion pathways was observed in cases with deregulated MAF and MAFB, whereas genes upregulated in cases with the t(4;14) showed apoptosis-related functions. The peculiar finding in patients with the t(11;14) was the downregulation of the α-subunit of the IL-6 receptor. In addition, we identified a set of cancer germline antigens specifically expressed in a subgroup of MM patients characterized by an aggressive clinical evolution, a finding that could have implications for patient classification and immunotherapy.

CD49d Is the Strongest Flow Cytometry–Based Predictor of Overall Survival in Chronic Lymphocytic Leukemia

PURPOSE Although CD49d is an unfavorable prognostic marker in chronic lymphocytic leukemia (CLL), definitive validation evidence is lacking. A worldwide multicenter analysis was performed using published and unpublished CLL series to evaluate the impact of CD49d as an overall (OS) and treatment-free survival (TFS) predictor. PATIENTS AND METHODS A training/validation strategy was chosen to find the optimal CD49d cutoff. The hazard ratio (HR) for death and treatment imposed by CD49d was estimated by pooled analysis of 2,972 CLLs; Cox analysis stratified by center and stage was used to adjust for confounding variables. The importance of CD49d over other flow cytometry-based prognosticators (eg, CD38, ZAP-70) was ranked by recursive partitioning. RESULTS Patients with ≥ 30% of neoplastic cells expressing CD49d were considered CD49d+. Decrease in OS at 5 and 10 years among CD49d+ patients was 7% and 23% (decrease in TFS, 26% and 25%, respectively). Pooled HR of CD49d for OS was 2.5 (2.3 for TFS) in univariate analysis. This HR remained significant and of similar magnitude (HR, 2.0) in a Cox model adjusted for clinical and biologic prognosticators. Hierarchic trees including all patients or restricted to those with early-stage disease or those age ≤ 65 years always selected CD49d as the most important flow cytometry-based biomarker, with negligible additional prognostic information added by CD38 or ZAP-70. Consistently, by bivariate analysis, CD49d reliably identified patient subsets with poorer outcome independent of CD38 and ZAP-70. CONCLUSION In this analysis of approximately 3,000 patients, CD49d emerged as the strongest flow cytometry-based predictor of OS and TFS in CLL.

CD26 expression in mature B-cell neoplasia: its possible role as a new prognostic marker in B-CLL.

CD26 (dipeptidyl peptidase IV, DPP IV) is widely expressed by T and natural killer (NK) cells, epithelial and endothelial cells of different tissues, and it is strongly upregulated in activated B‐cells; moreover it plays a regulatory role in the neoplastic transformation and progression of various types of tumours. CD26 expression was evaluated by means of flow cytometry in various peripheral B‐cell lymphoid tumours: 12 follicular and 12 mantle cell lymphomas, 20 multiple myelomas (MMs), 12 hairy cell leukaemias (HCLs), 112 chronic lymphocytic leukaemias (CLLs), 20 CD5negative B‐cell chronic lymphoproliferative diseases (CD5neg B‐CLPDs) and 12 diffuse large cell lymphomas (DLCLs). CD26 expression was absent or barely detectable in follicular and mantle cell lymphomas, high in MMs and HCLs, and variable in CLLs, in CD5neg B‐CLPDs and in DLCLs. CD26 significantly correlated with CD49d and CD38 expressions (p < 0.0001) in B‐CLLs, and there was a significant correlation between CD26 and ZAP‐70 expressions or IgVH mutational status (p < 0.0001). After a median follow‐up of 36 months, 65 B‐CLL patients were treated; taking 10% as the best CD26 cut‐off value, Kaplan–Meier curves revealed a significantly shorter time to treatment in the CD26‐positive cases (p < 0.0001). Overall, our data indicate that CD26 expression may identify subsets of B‐CLL patients with an unfavourable clinical outcome in terms of therapeutic need, thus suggesting its potential role as a marker (together with CD38 and CD49d) in a future routine cytofluorimetric panel to be validated for the prognostic stratification of B‐CLLs. Copyright

Poor prognosis in non-villous splenic marginal zone cell lymphoma is associated with p53 mutations

We have recently reported a series of 15 non‐villous splenic marginal zone lymphoma patients, six of whom showed p53 mutations (40%). This molecular alteration did not correlate with any particular clinico‐pathologic feature at diagnosis. After a median follow‐up of 56 months, four cases evolved into aggressive fatal non‐Hodgkins lymphoma (NHL) and two had refractory progressive disease; interestingly, p53 mutations were demonstrated in five of these patients at diagnosis. As the patients with wild‐type p53 presented responsive or indolent disease, this genetic alteration may be an early marker of aggressive transformation or refractoriness. p53 evaluation at diagnosis could be advisable in this particular subset of NHL.

Structure and Function of VLA Integrins: Differential Expression in B-Cell Leukemia/Lymphoma

The integrin family of adhesion receptors includes at least 11 different alpha subunits and 6 different beta subunits which are associated to form 14 different alpha beta heterodimers, divided into three subfamilies. In particular, beta 1 subfamily integrins (VLA 1-6 proteins) have been found to mediate cell adhesion to extracellular matrix (ECM) component such as fibronectin, collagen, laminin; however, VLA-4 has been found to exhibit both cell-cell and cell-matrix adhesion functions. The reactivity of VLAs is virtually ubiquitous and independent of line or tissue specificity. However, the expression of individual VLAs within single tissues can be modulated according to the type or functional status of the cell. One of the main reasons for interest in these molecules is that they may play a determining role in neoplastic transformation and diffusion; in particular, in lymphoproliferative syndromes, a lack of cell adhesiveness or an abnormal adhesion pattern in neoplastic lymphocytes may free these cells from regulation, thus contributing towards the development of leukemia and/or lymphoma. Studies of VLA expression in B-cell leukemia/lymphomas show a modulation of VLA3 and VLA4 reactivity. The most interesting element is the identification of a VLA3/VLA4 pattern associated with B-cell chronic lymphocytic leukemia (B-CLL) characterised by a reduced expression of VLA4 and the constant expression of VLA3. Although the value of VLA3 as an additional marker for the diagnosis of classical B-CLL is indisputable, the biological/functional significance of this reactivity remains to be confirmed.

Immunophenotypes in “classical” B-cell chronic lymphocytic leukemia. Correlation with normal cellular counterpart and clinical findings

This study evaluates the expression of a series of membrane antigens, normally expressed by B‐lymphocytes of the lymphocytic mantle and marginal zone, in 90 selected cases of “classical” (mouse red blood cell‐receptor+, CD20+, CD5+, surface immunoglobulin±) B‐chronic lymphocytic leukemia (B‐CLL) with the aim of contributing toward identifying the normal counterpart of B‐CLL and any correlations between surface antigen pattern and certain clinical characteristics. Clustered (CD23, 25, 39, 40, 27, 1c, w75) and unclustered (NuB1, 7F7, KiB3) monoclonal antibodies (MoAb) were tested. Almost all cases showed high reactivity to CD23, 27, w75, 39, 40, and NuB1: expression of CD1c was very low and that of 7F7, KiB3, and CD25 was variable. The reactivity of 7F7 and KiB3 was strictly correlated, and they correlated individually with CD25. Results show that the most frequent B‐CLL phenotype (CD19+, 5+, 23+, 27+, 39+, NuBl+, KiB3±, 7F7±, and CD25±) corresponds to one or more cellular subsets in the mantle zone. No correlation was found between MoAb expression, surface immunoglobulin (SIg) class or type, clinical stage, disease activity, or age at diagnosis. The only difference (statistically borderline) was the expression of 7F7 and KiB3 (in young versus old patients). This suggests that modulations in the expression of surface antigens do not affect the clinical behavior of the disease.

A multicenter retrospective clinical study of CD5/CD10‐negative chronic B cell leukemias

CD5‐negative chronic B cell lymphoproliferative disorders in leukemic phase (B‐CLPD) are heterogeneous and relatively uncommon pathologies that often lack a histopathological definition because of the absence of accessible pathological tissue. We describe the clinical features and evolution‐related variables of 156 patients with CD5/CD10‐negative B‐CLPD (median age 66 years, range 25–86). The median follow‐up was 51 months (range 6–216), and overall 3‐ and 5‐year survival was respectively 87 and 76%; 50 patients needed therapy at diagnosis, 56 during follow‐up, and 50 remained untreated until the last control. A combined clinical, histological, cytomorphological, immunophenotypical, and cytogenetic diagnostic approach allowed the complete classification of only a minority of patients as being affected by splenic marginal zone or lymphoplasmacytic lymphoma; the majority of cases remained unclassifiable. Multivariate analysis showed that the clinicohematological variables adversely related to overall survival were serum LDH levels and age, whereas high serum LDH levels, hemoglobin levels of <11 g/dl, and splenomegaly related to treatment‐free time (in “wait and see” cases); only splenomegaly related to time to progression (in treated patients). In conclusion, our retrospective study describes the clinical features and variables related to evolution in a large group of patients with CD5/CD10‐negative chronic B‐cell lymphoid leukemias and underlines the fact that a probable lymphoplasmacytic or marginal zone normal cell origin can be supposed in such leukemic forms, but never surely demonstrated. Am. J. Hematol. 2008.

BCL10 gene mutations rarely occur in lymphoid malignancies

BCL10, a gene involved in apoptosis signalling, has recently been identified through the cloning of chromosomal breakpoints in extranodal (MALT-type) marginal zone lymphomas carrying the t(1;14)(p22;q32) translocation. BCL10 was also found mutated in these cases as well as in other types of lymphoid and solid tumors, suggesting that its inactivation may play an important pathogenetic role; however, this has been questioned by recent studies showing a lack of somatic mutations in human cancers. We report the mutation analysis of exons 1–3 of the BCL10 gene in DNAs from 228 cases of lymphoid malignancies (30 B cell chronic lymphocytic leukemias, 123 B and 45 T non-Hodgkins lymphomas and 30 multiple myelomas). Somatic mutations were detected in four cases (2%): one small lymphocytic, one follicular and two diffuse large cell lymphomas. The mutations were all within exon 3 and have not been previously reported. Our data suggest that BCL10 mutations may play only a limited role in the pathogenesis of lymphoid neoplasms.

Diagnostic role and prognostic significance of a simplified immunophenotypic classification of mature B cell chronic lymphoid leukemias

We verified the diagnostic and prognostic role of a simplified immunophenotypic classification (IC) in a series of 258 patients (M/F: 1.4; median age: 64 years; median follow-up: 64 months; 75 deaths) with mature B cell lymphoid leukemias (MBC-LL) for whom no histopathological diagnosis was available because of minimal or no lymph node involvement. The IC was based on the reactivity of three pivotal immunophenotypic markers: CD5, CD23 and SIg intensity. On the basis of different expression patterns, we identified four diagnostic clusters (C) characterized by distinct clinico-biological features and different prognoses: C1 (149 patients) identified most classical B cell chronic lymphocytic leukemias (CLL-type cluster; SIgdim/CD5+/CD23+); C2, 38 patients whose clinico-hematological characteristics were intermediate between C1 and C3 (CLL-variant cluster; SIgbright/CD5+/CD23+/−or SIgdim/CD5−/−/CD23 indifferent); C3 (16 patients) most situations consistent with mantle cell lymphoma in leukemic phase (MCL-type cluster; SIgbright/CD5+/CD23−); and C4, 55 cases, most of whom were consistent with leukemic phase lymphoplasmacytic/splenic marginal zone lymphomas (LP/S-type cluster; SIgbright/CD5−/+/CD23 indifferent). At univariate survival analysis, prognosis worsened from C1 to C4, C2 and C3 (P = 0.0001), and this was maintained at multivariate analysis (P = 0.006), together with CD11c expression (P = 0.0043), age at diagnosis (cut-off 70 years; P = 0.0008) and platelet count (cut-off 140 × 109/l; P = 0.0034). Besides recognising the two well-known situations of classic B-CLL and MCL, our IC identified situations with distinct prognostic and/or clinical behaviors.

No correlation between response and survival in patients with multiple myeloma treated with vincristine, melphalan, cyclophosphamide, and prednisone

A vincristine, melphalan, cyclophosphamide, and prednisone (VMCP) multi‐drug regimen was used in 85 previously untreated patients with multiple myeloma (MM) (symptomatic Durie Stages II and III) until they became refractory. The prognostic significance of various pretreatment characteristics was evaluated in terms of therapeutic response (according to Southwest Oncology Group [SWOG] and Chronic Leukemia–Myeloma Task Force [TF] criteria) and survival. Therapeutic responses, obtained in 31.2% (SWOG) and 68.7% (TF) of patients, had a significant inverse correlation with myeloma cell mass, serum calcium, and bone status. Median survival time of Stage II and Stage III patients was 39 and 34 months, respectively. Serum B2 microglobulin greater than or equal to 6 μg/ml was the only variable correlating unfavorably with survival duration after multi‐variate analysis (increased risk = 2.79), although therapeutic response as a time‐dependent variable had no effect on survival. These data suggest no correlation between response and survival, partially because of inadequate response assessment criteria and partially because no existing treatment is curative (although current therapeutic approaches may prevent death from complications).