Michele Gottardi

High serum levels of B-lymphocyte stimulator are associated with clinical-pathological features and outcome in classical Hodgkin lymphoma

B‐lymphocyte stimulator (BLyS) acts as survival factor for B lymphocytes. As Hodgkin and Reed‐Sternberg (HRS) cells express receptors through which BLyS promotes their growth and chemotherapy resistance, we investgated whether this molecule was increased in sera from patients with classical Hodgkin lymphoma (cHL) and whether it correlates with clinical‐pathological features and outcomes. Enzyme‐linked immunosorbent assay was used to measure soluble BLyS (sBLyS) in sera from 87 patients and 33 donors; higher levels were detected in patients (meanu2003±u2003standard error 4493·9u2003±u2003264·9u2003pg/ml vs. 2687·0u2003±u2003200·9u2003pg/ml; Pu2003<u20030·0001). Levels above the median value (4242·0u2003pg/ml) were associated with age ≥45u2003years (Pu2003=u20030·042), advanced stages of disease (Pu2003=u20030·005), systemic symptoms (Pu2003=u20030·014) and extranodal involvement (Pu2003=u20030·009). Five‐year failure‐free survival (FFS) of patients with sBLyS below or equal to median levels was 88·6% as compared to 65·1% of those with levels above the median (Pu2003=u20030·009). Statistical analyses confirmed the prognostic significance of sBLyS (Pu2003=u20030·046). When patients were analysed according to variables associated with high levels, sBLyS showed an independent predictive power in terms of FFS. Our findings support the involvement of BLyS in cHL pathogenesis. The association between high serum levels and an inferior FFS indicates that sBLyS is a possible prognostic predictor with a potential significance as a therapeutic target.

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.

Concomitant chronic lymphocytic leukemia and acute myeloid leukemia: evidence of simultaneous expansion of two independent clones.

The simultaneous appearance of chronic lymphocytic leukemia (CLL) and acute myeloid leukemia (AML) has been rarely reported, with AML occurring more frequently as a secondary event in patients receiving cytotoxic drugs for a primary lymphoproliferative disorder. We describe a case of simultaneous CLL and AML documented by morphological and cytometric analysis in a previously untreated patient. In particular, on the basis of morphological and immunological features, the patient was diagnosed as being affected by CD34 + /CD13 + /CD33 + /HLA-DR + /CD7 + FAB-M2 AML, along with a B-CLL characterized by neoplastic cells expressing a VH3-53/D3-22/JH4 Ig, bearing, on average, 3.9% IgVH mutations without evidence of antigen-driven selection. To establish whether the two neoplastic cell populations shared some common molecular signature, we performed IgH gene rearrangement studies on CD34 + /CD19− and CD34−/CD19 + immunomagnetically sorted cell populations: only genomic DNA from the CD19 + /CD34− cell fraction revealed the presence of the IgH gene rearrangement. These results provide evidence that the rare concomitant association of CLL and AML likely arises from simultaneous expansion of two independent clones.

Complete remission induced by thalidomide in a case of angioimmunoblastic T-cell lymphoma refractory to autologous stem cell transplantation

Angioimmunoblastic T-cell lymphoma (AITL) is a peripheral T-cell lymphoma characterised by a very aggressive clinical course. Despite conventional treatment, usually intensive adriamycin-containing chemotherapy, patients affected by AITL have a poor prognosis with a median survival of less than 3 years [1]. High-dose chemotherapy with stem cell transplantation (HDCT/ASCT) may rescue patients who fail to achieve the complete remission (CR) after induction chemotherapy, finally leading to an improved long-term event-free survival [2], but chemosensitivity is the widely accepted requirement at the time of transplantation [3]. In this scenario, efforts to identify novel approaches aimed at overcoming resistance to conventional cytotoxic agents are warranted. Here we present a case of AITL refractory both to first line chemotherapy and HDCT/ASCT that achieved a 6-month lasting CR with thalidomide alone. The patient was a 52-year-old male who presented in November 2005 complaining of a 2-month history of systemic symptoms. Physical examination and positron emission tomography/computed tomography scan (PET/CT) showed generalised lymphadenopathies, marked splenomegaly, mild hepatomegaly and bilateral pleural effusions. Laboratory evaluation documented pancytopenia with evidence of concomitant autoimmune hemolytic anemia (increased unconjugated bilirubin, reduction of plasma haptoglobin levels and positive direct antiglobulin test) and hypergammaglobulinemia. Biopsy of a left axillary lymph node confirmed AITL. Trephine bone marrow biopsy showed a diffuse infiltrate of lymphoma cells. Because of the hemolytic process, first line therapy was based on prednisone 1 mg/kg/day with a rapid improvement of the hemoglobin level. Starting in December 2005 the patient received MACOP-B regimen (methotrexate 400 mg/m weeks 2, 6 and 10 with leucovorin rescue, doxorubicin 50 mg/m weeks 1, 3, 5, 7, 9 and 11, cyclophosphamide 350 mg/m weeks 1, 3, 5, 7, 9 and 11, vincristine 1.4 mg/m weeks 2, 4, 6, 8, 10 and 12, prednisone 40 mg/m weeks 1–12, and bleomycin 10 mg/m weeks 4, 8 and 12) that induced only a partial reduction of B-symptoms. BFM protocol (cycle A: methotrexate 3000 mg/m day 1 with leucovorin rescue, vincristine 2 mg/m day 1, cyclophosphamide 200 mg/m days 1–4, doxorubicin 25 mg/m day 4, dexamethasone 10 mg/m days 1–4; cycle B: methotrexate 3000 mg/ m day 1 with leucovorin rescue, vincristine 2 mg/m day 1, ifosfamide 800 mg/m days 1–4, cytosine arabinoside 150 mg/m day 4, VM-26 100 mg/m day 4, dexamethasone 10 mg/m days 1–4) was delivered as salvage therapy starting in April 2006. After two cycles of the latter therapy, although the complete resolution of systemic symptoms was observed, only a partial reduction (550%) of lymphadenopathies and of splenomegaly was documented. Bone marrow lymphoma infiltration reduced to less than 10%. We then addressed the

Flai (fludarabine, cytarabine, idarubicin) plus low-dose Gemtuzumab Ozogamicin as induction therapy in CD33-positive AML: Final results and long term outcome of a phase II multicenter clinical trial

The aim of this prospective clinical trial was to evaluate the efficacy and safety of a combination of Gemtuzumab‐Ozogamicin (GO) and FLAI scheme (fludarabine, cytarabine, idarubicin) as a first‐line therapy in CD33 positive AML. We treated 130 patients, aged <65, with a median age of 52 years. FLAI‐GO induction regimen included fludarabine (30 mg/sqm) and cytarabine (2 g/sqm) on days 1–5; idarubicin (10 mg/sqm) on days 1, 3, and 5; and GO (3 mg/sqm) on day 6. SCT was planned for all high‐risk AML patients, after consolidation with intermediate doses of cytarabine and idarubicin and a high dose of cytarabine. CD33 expression exceeded 20% in all cases. Primary endpoints of the study included feasibility, overall response rate (ORR) and toxicity. Secondary endpoints included the evaluation of MRD by WT1 expression, feasibility and outcome of consolidation with SCT, overall survival (OS) and disease‐free survival (DFS).

Stem Cell Modeling of Core Binding Factor Acute Myeloid Leukemia.

Even though clonally originated from a single cell, acute leukemia loses its homogeneity soon and presents at clinical diagnosis as a hierarchy of cells endowed with different functions, of which only a minority possesses the ability to recapitulate the disease. Due to their analogy to hematopoietic stem cells, these cells have been named “leukemia stem cells,” and are thought to be chiefly responsible for disease relapse and ultimate survival after chemotherapy. Core Binding Factor (CBF) Acute Myeloid Leukemia (AML) is cytogenetically characterized by either the t(8;21) or the inv(16)/t(16;16) chromosomal abnormalities, which, although being pathognomonic, are not sufficient per se to induce overt leukemia but rather determine a preclinical phase of disease when preleukemic subclones compete until the acquisition of clonal dominance by one of them. In this review we summarize the concepts regarding the application of the “leukemia stem cell” theory to the development of CBF AML; we will analyze the studies investigating the leukemogenetic role of t(8;21) and inv(16)/t(16;16), the proposed theories of its clonal evolution, and the role played by the hematopoietic niches in preserving the disease. Finally, we will discuss the clinical implications of stem cell modeling of CBF AML for the therapy of the disease.

Clinical and experimental efficacy of gemtuzumab ozogamicin in core binding factor acute myeloid leukemia

Leukemia-initiating cells of core binding factor (CBF) acute myeloid leukemia (AML) likely derive from early committed hematopoietic precursors expressing CD33. As such, targeting CD33 could ameliorate the chance of cure of CBF AML patients. We compared 12 CBF AML patients treated with Fludarabine, Cytarabine, Idarubicin and Gemtuzumab Ozogamicin (FLAI-GO regimen) with 25 CBF AML patients treated with the same schedule, but without GO. With the limit of small numbers, we observed a consistent trend toward better overall survival, disease free survival and event free survival in the FLAI-GO group. We also demonstrated the ability of GO to induce the disappearance in vitro of the AML1-ETO molecular transcript in a polymerase chain reaction-positive graft without decreasing the clonogenic potential of CD34+/CD38- cells. This represent the proof of principle for using GO in a purging strategy before autologous stem cell transplantation. Therefore, our data argue in favor of the reinstitution of GO in the therapy of CBF AML.

Adrenomedullin in the growth modulation and differentiation of acute myeloid leukemia cells

Adrenomedullin (ADM) is a regulatory peptide endowed with multiple biological effects, including the regulation of blood pressure, cell growth and innate host defence. In the present study, we demonstrated that ADM signaling could be involved in the impaired cellular differentiation of myeloid leukemia cells to mature granulocytes or monocytes by modulating RAMPs/CRLR expression, PI3K/Akt cascade and the ERK/MAPK signaling pathway. When exogenously administered to in vitro cultures of HL60 promyelocytic leukemia cells, ADM was shown to exert a strong proliferative effect with minimal upregulation in the expression level of monocyte antigen CD14. Notably, the experimental inhibition of ADM signaling with inhibitor ADM22-52 promoted a differentiative stimulation towards monocytic and granulocytic lineages. Moreover, based on the expression of CD31 relative to CD38, we hypothesized that an excess of ADM in bone marrow (BM) niche could increase the transendothelial migration of leukemia cells while any inhibitory event of ADM activity could raise cell retention in hyaluronate matrix by upregulating CD38. Taken into consideration the above evidence, we concluded that ADM and ADM22-52 could differently affect the growth of leukemia cells by autocrine/paracrine mechanisms and may have clinical relevance as biological targets for the intervention of tumor progression.