Cross-talk between chronic lymphocytic leukemia (CLL) tumor B cells and mesenchymal stromal cells (MSCs): implications for neoplastic cell survival

Leukemic cells from Chronic Lymphocytic Leukemia (CLL) patients interact with stromal cells of the surrounding microenvironment. Mesenchymal Stromal Cells (MSCs) represent the main population in CLL marrow stroma, which may play a key role for disease support and progression. In this study we evaluated whether MSCs influence in vitro CLL cell survival. MSCs were isolated from the bone marrow of 46 CLL patients and were characterized by flow cytometry analysis. Following co-culture of MSCs and leukemic B cells, we demonstrated that MSCs were able to improve leukemic B cell viability, this latter being differently dependent from the signals coming from MSCs. In addition, we found that the co-culture of MSCs with leukemic B cells induced an increased production of IL-8, CCL4, CCL11, and CXCL10 chemokines.As far as drug resistance is concerned, MSCs counteract the cytotoxic effect of Fludarabine/Cyclophosphamide administration in vivo, whereas they do not protect CLL cells from the apoptosis induced by the kinase inhibitors Bafetinib and Ibrutinib. The evidence that leukemic clones are conditioned by environmental stimuli suggest new putative targets for therapy in CLL patients.     

State of the art in natural killer cell malignancies

The recently updated World Health Organization (WHO) classification of tumors of hematopoietic and lymphoid tissues, published in 2008, has made great advances in revising the disorders previously included in the pool of natural killer (NK) cell tumors. Although NK cell neoplasms represent a relatively rare group of diseases, accounting for <5% of all lymphoid neoplasms, they include very distinctive conditions both clinically and pathologically. This family of diseases includes the most indolent clinical forms, such as the provisional new entry of chronic lymphoproliferative disorder of NK cells (CLPD-NK) in the WHO classification, as well as one of the most fatal diseases recognized in medical oncology, aggressive NK cell leukemia (ANKL), which is characterized by a prognosis of weeks, or even days. In addition, some disorders previously identified as blastic NK cell lymphoma within the NK cell system have been more properly defined and included in the blastic plasmacytoid dentritic cell neoplasms, although rare cases of bona fide immature NK lymphoid tumors (now classified as NK cell lymphoblastic leukemia/lymphoma) have been reported in the literature. This paper focuses on recent concepts and progress in morphology, pathogenesis, clinicopathological features, treatment approaches, and outcomes of NK cell malignancies.     

Rituximab-responsive CIDP

Chemotherapy has been used for treating chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) with incosistent results. Chemotheraphy has been used for treating with inconsistent results. Rituximab is a chimeric monoclonal antibody directed against the CD20 antigen, used to treat B-cell lymphoma and reported to be effective in some neuropathies with IgM autoreactivity. We saw a 72-year-old man with CIDP refractory to steroids, plasma exchange, IV Ig, and cyclosporin. He was unable to walk; severe impairment was present also at the upper limbs. Electrodiagnostic studies revealed slowing of motor and sensory conduction velocities, and prolonged distal motor latencies. Immunoelectrophoresis evidence an IgM/k monoclonal gammopathy. Antibodies to Myelin Associated Glycoprotein (MAG) and other peripheral nerve antigens were negative. Bone marrow biopsy documented a small lymphocytic B-cell lymphoma (CD20+). Treated with Rituximab (375 mg/m² for 4 weeks), the patient presented at follow-up evaluations (3, 6 and 8 months later) a progressive improvement. Eventually, he was able to walk, and regained full strength at upper limbs. Consistently, electrophysiological studies improved. We suggest considering treatment with Rituximab in CIDP resistant to conventional therapy, at least in cases associated with IgM lymphoproliferative diseases.     

The raft marker GM1 identifies functional subsets of granular lymphocytes in patients with CD3+ lymphoproliferative disease of granular lymphocytes.

The raft marker GM1 is expressed at very low levels at the plasma membrane of resting T cells (GM1dull). In vitro T-cell activation induces synthesis of this lipid, which is then expressed at very high levels (GM1bright) at the membrane of activated/effector cells. By flow cytometry and confocal microscopy, we analyzed the expression and organization of GM1 in a series of 15 patients with CD3+ lymphoproliferative disease of granular lymphocytes (LDGL). We found that GM1bright GL were detectable in fresh blood samples obtained in all LDGL patients, although the range of brightly stained cells was extremely variable. This distinctive in vivo pattern has never been shown in T lymphocytes from healthy individuals or in patients with different chronic T or B lymphoproliferative disorders or active infectious diseases. The low number of cycling cells detected in LDGL patients was always included within the GM1bright GL population. Interestingly, GM1bright GL were demonstrated to contain a higher amount of IFN-gamma as compared to GM1dull GL. These findings allow to distinguish subsets of GL at different levels of activation within the monoclonal CD3+ population. The GM1bright GL subset is likely to be responsible for the renewing of GL and thus for maintaining chronic proliferation.     

Pulmonary alveolar macrophages from patients with active sarcoidosis express type IV collagenolytic proteinase. An enzymatic mechanism for influx of mononuclear phagocytes at sites of disease activity.

Alveolar macrophages (AMs) recovered from the bronchoalveolar lavage (BAL) of 44 patients with sarcoidosis were evaluated for their ability to release type IV collagenolytic metalloproteinase (IV-Case). This enzyme, which is produced by peripheral blood monocytes (PBMs) but not by tissue macrophages, degrades type IV collagen, the major structural component of vessel wall basement membranes, and helps to promote the migration of PBMs from the blood compartment to peripheral tissues. Our results demonstrated that AMs from patients with active sarcoidosis released significantly increased levels of IV-Case with respect to patients with inactive disease and control subjects. After in vitro culture, sarcoid AMs secreted IV-Case during the first 24 h of collection; after that time, AMs progressively lost their ability to release IV-Case. Exposition of both sarcoid and normal AMs to recombinant IL 2 or gamma IFN did not influence their property to release IV-Case. The immunoblot analysis of IV-Case demonstrated complete identity between IV-Case released by AMs and the degradative enzyme obtained from PBMs. The increased property to release IV-Case was significantly related to the increase of the absolute number of AMs and, in particular, of AMs bearing two determinants that are usually expressed by most PBMs (CD11b and CD14). Selective depletion of CD11b+/CD14+ AMs from the entire macrophagic population was associated with the recovery of the IV-Case activity to normal values. A positive correlation was also found between the increase in the absolute number of lung T cells and the enhanced CD4/CD8 pulmonary ratio. A 6-mo follow-up study indicated a significant association between the positivity for the 67Gallium scan and the increased property of AMs to release IV-Case. Our data are consistent with the hypothesis that a IV-Case mediated influx of peripheral monocytes takes place in the lung of sarcoid patients. Furthermore, the correlation found between the IV-Case release and disease activity suggests that this assay could represent a useful tool in sarcoidosis disease staging.     

Bronchoalveolar lavage and lung histology. Comparative analysis of inflammatory and immunocompetent cells in patients with sarcoidosis and hypersensitivity pneumonitis

To determine whether bronchoalveolar lavage reflects the histologic aspects of the lung histology in patients with sarcoidosis and hypersensitivity pneumonitis, cells recovered from lavage fluid were compared with tissue sections from transbronchial lung biopsies in 33 patients. The evaluation of cellular types and their topographic distribution in situ was determined by using monoclonal antibodies in combination with immunohistochemical techniques. Cell counts in bronchoalveolar lavage and lung biopsies were significantly correlated both in sarcoidosis and hypersensitivity pneumonitis. In fact, the relative proportions of inflammatory and immunocompetent cells recovered from lavage fluid accurately overlapped those observed in lung tissue sections. However, in patients with more pronounced alveolitis, the frequency of macrophages in tissue sections was higher than that observed in the bronchoalveolar lavage, and the degree of lymphocytes in the lavage was higher than that observed in the corresponding biopsy. Specifically, in these patients the lavage underestimated the amount of macrophages in the lung biopsies and overestimated the number of lymphocytes that were present in the lung parenchyma. This was more evident in patients with hypersensitivity pneumonitis, where the intensity of alveolitis was higher than in sarcoidosis. Our data support the idea that, at least in patients with sarcoidosis and hypersensitivity pneumonitis, bronchoalveolar lavage correctly samples the alveolitis. Discrepancies in patients with very high intensity alveolitis could be due to a more pronounced recirculation of lymphocytes from the parenchyma to the alveolar spaces.     

Complex karyotype,older age,and reduced first‐line dose intensity determine poor survival in core binding factor acute myeloid leukemia patients with long‐term follow‐up

Approximately 40% of patients affected by core binding factor (CBF) acute myeloid leukemia (AML) ultimately die from the disease. Few prognostic markers have been identified. We reviewed 192 patients with CBF AML, treated with curative intent (age, 15–79 years) in 11 Italian institutions. Overall, 10‐year overall survival (OS), disease‐free survival (DFS), and event‐free survival were 63.9%, 54.8%, and 49.9%, respectively; patients with the t(8;21) and inv(16) chromosomal rearrangements exhibited significant differences at diagnosis. Despite similar high complete remission (CR) rate, patients with inv(16) experienced superior DFS and a high chance of achieving a second CR, often leading to prolonged OS also after relapse. We found that a complex karyotype (i.e., ≥4 cytogenetic anomalies) affected survival, even if only in univariate analysis; the KIT D816 mutation predicted worse prognosis, but only in patients with the t(8;21) rearrangement, whereas FLT3 mutations had no prognostic impact. We then observed increasingly better survival with more intense first‐line therapy, in some high‐risk patients including autologous or allogeneic hematopoietic stem cell transplantation. In multivariate analysis, age, severe thrombocytopenia, elevated lactate dehydrogenase levels, and failure to achieve CR after induction independently predicted longer OS, whereas complex karyotype predicted shorter OS only in univariate analysis. The achievement of minimal residual disease negativity predicted better OS and DFS. Long‐term survival was observed also in a minority of elderly patients who received intensive consolidation. All considered, we identified among CBF AML patients a subgroup with poorer prognosis who might benefit from more intense first‐line treatment. Am. J. Hematol. 90:515–523, 2015. © 2015 Wiley Periodicals, Inc.     

Bortezomib,cyclophosphamide, dexamethasone versus lenalidomide,cyclophosphamide, dexamethasone in multiple myeloma patients at first relapse

Bortezomib- and lenalidomide-containing regimens are well-established therapies in multiple myeloma (MM). However, despite their extensive use, head-to-head comparisons have never been performed. Therefore, we compared bortezomib and lenalidomide in fixed-duration therapies. In this open-label, phase III study, we randomized MM patients at first relapse to receive either nine cycles of bortezomib plus cyclophosphamide plus dexamethasone (VCD) or lenalidomide plus cyclophosphamide plus dexamethasone (RCD). The primary endpoint was achievement of a very good partial response (VGPR) or better at six weeks after nine treatment cycles. From March 2011 to February 2015, 155 patients were randomized. VGPR or better was achieved by 12 patients (15%) in the VCD arm and 14 patients (18%) in the RCD arm (P = 0·70). Median progression-free survival (PFS) was 16·3 (95% CI: 12·1–22·4) with VCD and 18·6 months (95% CI: 14·7–25·5) with RCD, and the two-year overall survival (OS) was 75% (95% CI: 66–86%) and 74% (95% CI: 64–85%) respectively. In subgroup analyses, no differences in PFS were observed in bortezomib- and lenalidomide-naïve patients, nor in patients who received a bortezomib-based regimen in first line. Adverse events were consistent with the well-established safety profiles of both drugs. Bortezomib and lenalidomide treatments were equally effective in terms of depth of response, PFS, and OS in MM patients at first relapse.