Dina Attias

bcl-2 and immunoglobulin gene rearrangement in patients with hepatitis C virus infection

An association between chronic hepatitis C virus (HCV) infection and clonal proliferation of B cells, including B cell lymphoma, has recently been demonstrated. However, the mechanism of malignant transformation is still unknown. It has been shown that B cells from patients with type II mixed cryoglobulinaemia (MC), strongly express the antiapoptotic bcl‐2 oncogene product. Therefore, we investigated a possible mechanism of lymphomagenesis, the occurrence of bcl‐2 and immunoglobulin gene rearrangement (IgH) in HCV‐infected patients. Three groups of patients were studied: (1) 44 patients with HCV and MC (anti‐HCV and HCV RNA positive); (2) 59 patients with chronic HCV infection without MC; (3) 50 patients with chronic liver disease (CLD) not related to HCV infection. The t(14;18) translocation (MBR bcl‐2–JH) and IgH rearrangement (FR3/JH) were detected by polymerase chain reaction (PCR) in peripheral mononuclear cells. bcl‐2 translocation was detected in 17/44 (39%), 7/59 (12%) and in none of the patients of groups 1, 2 and 3 respectively (P < 0·01). Monoclonal IgH rearrangement was detected in 15/44 (34%), 5/59 (8·5%) and 2/50 (4%) patients of groups 1, 2 and 3 respectively (P < 0·05). HCV‐infected patients had a higher prevalence of monoclonal IgH rearrangement and bcl‐2 translocation than patients with CLD of other aetiologies. These data suggest that HCV may play a role in the multistep mechanism of lymphomagenesis by inducing clonal proliferation of B cells and inhibition of apoptosis.

Myeloid-derived suppressor cells--their role in haemato-oncological malignancies and other cancers and possible implications for therapy.

Myeloid‐derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells at different stages of maturation that play a role in cancer tolerance and function as an immune‐suppressive cell subpopulation. They utilize different mechanisms to block both innate and adaptive arms of anti‐tumour immunity, mostly through inhibition of T cell activation and expansion. Further advances in our understanding of this cell population in both murine models and humans has enabled more accurate characterization of their phenotype and the recognition of two major classes of MDSCs: granulocytic and monocytic. Recently, the mechanism of action and clinical importance of MDSCs has been more clearly defined and their interactions with cancer cells have been shown to be among the factors influencing tumour development and induction of tolerance. Most of the earlier studies were performed using murine models, but recent clinical investigations have shown their potential role in human cancers. Here, we review the origin of MDSCs, their mechanisms of action, the factors influencing their production and related signalling pathways. We focus on their role in human solid tumours and haemato‐oncological malignancies, and relate to possible novel therapeutic approaches targeting MDSCs which could be considered together with other anticancer strategies in the not too distant future.

Absolute monocytosis at diagnosis correlates with survival in diffuse large B‐cell lymphoma—possible link with monocytic myeloid‐derived suppressor cells

Some patients with lymphoma have monocytosis at diagnosis, but its significance is unclear. The recently recognized subpopulation, monocytic myeloid‐derived suppressor cells (M‐MDSCs), has immunoregulatory function, suppresses host anti‐tumour immunity and plays a role in cancer tolerance. Data from 91 untreated patients with diffuse large B‐cell lymphoma (DLBCL) were evaluated for monocytosis >1000/mm3 at diagnosis and its significance compared with a number of well‐established prognostic factors for DLBCL including age, stage, gender, B symptoms, extranodal sites, LDH and CRP levels, bone marrow involvement and International Prognostic Index (IPI) score. In 23 of these patients with DLBCL and 15 healthy controls, the proportion of M‐MDSCs in the peripheral blood was determined by flow cytometry. Monocytosis was found in 17.6% of the patient cohort examined. In the multivariate analysis, bone marrow involvement, IPI score and monocytosis were the only independent prognostic factors seen to be associated with decreased progression free and overall survival. Patients with DLBCL had on average increased M‐MDSCs counts at diagnosis compared with controls, which returned to normal after achieving remission. In conclusion, monocytosis was identified as an independent prognostic factor in DLBCL and correlated with worse overall survival. The significant increases in the M‐MDSCs pool observed in some of the cases examined may possibly help to explain why monocytosis is associated with poor outcome in these patients. Copyright

Frequency and natural history of inherited bone marrow failure syndromes: the Israeli Inherited Bone Marrow Failure Registry

Background Inherited bone marrow failure syndromes are rare genetic disorders characterized by bone marrow failure, congenital anomalies, and cancer predisposition. Available single disease registries provide reliable information regarding natural history, efficacy and side effects of treatments, and contribute to the discovery of the causative genes. However, these registries could not shed light on the true incidence of the various syndromes. We, therefore, established an Israeli national registry in order to investigate the relative frequency of each of these syndromes and their complications. Design and Methods Patients were registered by their hematologists in all 16 medical centers in Israel. We included patients with Fanconi anemia, severe congenital neutropenia, Diamond-Blackfan anemia, congenital amegakaryocytic thrombocytopenia, dyskeratosis congenita, Shwachman-Diamond syndrome, and thrombocytopenia with absent radii. Results One hundred and twenty-seven patients diagnosed between 1966 and 2007 were registered. Fifty-two percent were found to have Fanconi anemia, 17% severe congenital neutropenia, 14% Diamond-Blackfan anemia, 6% congenital amegakaryocytic thrombocytopenia, 5% dyskeratosis congenita, 2% Shwachman-Diamond syndrome, and 2% thrombocytopenia with absent radii. No specific diagnosis was made in only 2 patients. Of the thirty patients (24%) developing severe bone marrow failure, 80% had Fanconi anemia. Seven of 9 patients with leukemia had Fanconi anemia, as did all 6 with solid tumors. Thirty-four patients died from their disease; 25 (74%) had Fanconi anemia and 6 (17%) had severe congenital neutropenia. Conclusions This is the first comprehensive population-based study evaluating the incidence and complications of the different inherited bone marrow failure syndromes. By far the most common disease was Fanconi anemia, followed by severe congenital neutropenia and Diamond-Blackfan anemia. Fanconi anemia carried the worst prognosis, with severe bone marrow failure and cancer susceptibility. Diamond-Blackfan anemia had the best prognosis. The data presented provide a rational basis for prevention programs and longitudinal surveillance of the complications of inherited bone marrow failure syndromes.

Rozrolimupab, a mixture of 25 recombinant human monoclonal RhD antibodies, in the treatment of primary immune thrombocytopenia

Rozrolimupab, a recombinant mixture of 25 fully human RhD-specific monoclonal antibodies, represents a new class of recombinant human antibody mixtures. In a phase 1 or 2 dose escalation study, RhD(+) patients (61 subjects) with primary immune thrombocytopenia received a single intravenous dose of rozrolimupab ranging from 75 to 300 μg/kg. The primary outcome was the occurrence of adverse events. The principal secondary outcome was the effect on platelet levels 7 days after the treatment. The most common adverse events were headache and pyrexia, mostly mild, and reported in 20% and 13% of the patients, respectively, without dose relationship. Rozrolimupab caused an expected transient reduction of hemoglobin concentration in the majority of the patients. At the dose of 300 μg/kg platelet responses, defined as platelet count ≥ 30 × 10(9)/L and an increase in platelet count by > 20 × 10(9)/L from baseline were observed after 72 hours and persisted for at least 7 days in 8 of 13 patients (62%). Platelet responses were observed within 24 hours in 23% of patients and lasted for a median of 14 days. Rozrolimupab was well tolerated and elicited rapid platelet responses in patients with immune thrombocytopenia and may be a useful alternative to plasma-derived products. This trial is registered at www.clinicaltrials.gov as #NCT00718692.

The efficacy of rituximab in high-grade pediatric B-cell lymphoma/leukemia: a review of available evidence.

Purpose of review This review evaluates whether rituximab has efficacy in high-grade pediatric B-cell lymphoma/leukemia. Current pediatric protocols for CD20+ B-cell lymphoma/leukemia significantly improve survival, but with major morbidity. To assess whether rituximab has efficacy in very high-grade pediatric disease, all published data on rituximab therapy for Burkitts lymphoma/B acute lymphoblastic leukaemia (B-ALL) and pediatric patients with relapsed/refractory large B-cell lymphoma were reviewed. Recent findings Three trials in adult Burkitts/B-ALL showed a significant survival advantage when rituximab was added to standard chemotherapy. Minimal pediatric data have been published, but 19 children with mature B-cell lymphoma/B-ALL received rituximab, alone or in combination with chemotherapy, as salvage therapy, after failure of intensive chemotherapy. Fifteen of 19 (79%) responded, 12 (63%) remained alive in continuous complete remission at 5+ to 48+ months of follow-up. Two patients were alive in partial remission. Five patients died, four of progressive disease. Only one patient had no response to rituximab. Summary Rituximab has demonstrated efficacy in Burkitts disease in adults. Although positive reporting bias is suspected, it appears that rituximab, even as monotherapy, has efficacy in heavily pretreated pediatric patients with high-grade B-lymphoma/B-ALL. Rituximab use can be justified in a prospective controlled chemotherapy dose-reduction study.

Acute neutrophilic myositis in sweet's syndrome: Late phase transformation into fibrosing myositis and panniculitis

Early in the course of myeloblastic leukemia a patient concurrently developed febrile neutrophilic dermatosis and sterile acute myositis. The dermatitis and myositis were unresponsive to antibiotic therapy but remitted within a few days of institution of steroid treatment. The patient died of myocardial infarction. At autopsy the dermis was normal. Previously effected muscles were scarred. The overlying fascia and subcutaneous septa were fibrotically thickened. In addition, segmental acute aortitis was detected. Acute myositis and aortitis may reflect further organ manifestations of the Sweets reactivity pattern. It is proposed that Sweets myositis and dermatitis may evolve into a fibrosing myositis and panniculitis.

The expression of lysyl-oxidase gene family members in myeloproliferative neoplasms.

Myeloproliferative neoplasms (MPNs) are malignant disorders originating from clonal expansion of a single neoplastic stem cell and characteristically show an increase in bone marrow reticulin fibers. Lysyl oxidases (LOXs) are copper‐dependent amine oxidases that play a critical role in the biogenesis of connective tissue by crosslinking extracellular matrix proteins, collagen and elastin. Expression of LOX gene family members is increased in disorders associated with increased fibrosis. To evaluate involvement of LOX gene family in various MPNs. In‐situ hybridization was used to detect Lysyl‐Oxidase family members in bone marrow biopsies from patients with different MPNs. We compared normal bone marrows and those from patients with polycythemia vera, essential thrombocythemia, chronic myeloid leukemia, and primary myelofibrosis (PMF). Serum levels of lysyl‐oxidase from patients with PMF and healthy controls were also examined. LOX gene family was not detected in normal bone marrows. All members of the LOX gene family were over expressed in PMF. In other MPNs a differential pattern of expression was observed. Differences in gene expression were statistically significant (P < 0.010). The medianserum LOX levels in normal controls was 28.4 ± 2.5 ng\ml and 44.6 ± 9.44 ng\ml in PMF (P = 0.02). The varying pattern of expression of LOX genes may reflect differences in the pathophysiology of bone marrow fibrosis in these MPNs. These observations could be used as the basis for future targeted therapy directed against bone marrow fibrosis. Am. J. Hematol. 88:355–358, 2013.

Long-term results of the Israeli National Studies in childhood acute lymphoblastic leukemia: INS 84, 89 and 98

Long-term results of the Israeli National Studies in childhood acute lymphoblastic leukemia: INS 84, 89 and 98

Molecular characterization of three novel Fanconi anemia mutations in Israeli Arabs

Objectives:  In a previous study, we investigated the molecular basis of Fanconi anemia (FA) in 13 unrelated Israeli Jewish FA patients and identified four ethnicity specific mutations. In the present study we extended our study to Israeli Arab patients.