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Based upon the clinical behavior of three patients, we suggest that the combination of low-dose Ara-C and all-trans retinoic acid may potentially be effective in some elderly patients, unfit for intensive chemotherapy, affected with NPM1-mutated acute myeloid leukemia without FLT3 mutations, warranting perspective clinical studies in these selected patients.

Chronic/recurrent behaviour may be encountered in some distinct atypical or malignant lymphoproliferations, while recurrences are not generally observed in reactive/benign lymphadenopathies. We retrospectively analysed a consecutive series of 486 human immunodeficiency virus-negative adults, who underwent lymphadenectomy. Neoplastic and benign/reactive histopathological pictures were documented in 299 (61·5%) and 187 (38·5%) cases, respectively. Of note, seven of the 111 (6·3%) patients with benign lymphadenopathy without well-defined aetiology, showed chronic/recurrent behaviour, without constitutional symptoms. Enlarged lymph nodes were round in shape and hypoechoic, mimicking lymphoma. Reactive follicular hyperplasia and paracortical expansion were observed. Human herpesvirus (HHV)-6B positive staining in follicular dendritic cells (FDCs) was documented in all seven patients. Serological, molecular and immunological examinations suggested HHV-6B reactivation. Among the remaining 104 cases with reactive lymphoid hyperplasia in the absence of well-known aetiology and without recurrences, positivity for HHV-6B on FDCs was found in three cases, whereas in seven further patients, a scanty positivity was documented in rare, scattered cells in inter-follicular regions. Immunohistochemistry for HHV-6A and HHV-6B was invariably negative on 134 lymph nodes, with either benign pictures with known aetiology or malignant lymphoproliferative disorders, tested as further controls. Future studies are warranted to investigate a potential association between HHV-6B reactivation and chronic/recurrent benign lymphadenopathy.

In the last few years, new drugs able to inhibit the B-cell receptor (BCR) pathway have been approved by the US and European drug control agencies for the treatment of chronic lymphocytic leukemia (CLL) and some indolent B lymphomas. Among them, ibrutinib and idelalisib, respectively, target the

Biosimilars of filgrastim have shown to be comparable to the originator (Neupogen®, Amgen Inc., CA) in terms of pharmacodynamic response in healthy subjects, as well as in overall efficacy and safe...

Fusion genes derived from the platelet-derived growth factor receptor beta (PDGFRB) or alpha (PDGFRA) play an important role in the pathogenesis of eosinophilia-associated myeloproliferative neopla...

Endothelin-1 (ET-1) is a hormone peptide widely expressed and is involved in several biological processes, important not only for normal cell function but also for tumor development, including cell proliferation, invasion, metastasis, angiogenesis and osteogenesis. In accordance, ET-1 was already shown to contribute to the growth and progression of many different solid cancers. We recently demonstrated that ET-1 has a role in the pathogenesis of chronic lymphocytic leukemia (CLL) where it is abnormally expressed. In the context of this malignancy, ET-1 is able to mediate survival, drug-resistance and growth signals in leukemic cells. Previous studies, not conducted in CLL, have shown that ET-1 regulatory mechanisms are numerous and cell specific. Here, we valued the expression of ET-1 in CLL, in relation to DNA methylation but also in response to stimulation of some important pathways for the dialogue between CLL and microenvironment. We found that a high methylation of ET-1 first intron affects the basal expression of ET-1 in CLL. Moreover, we showed that the activation of CD40 or Toll-like receptor (TLR) by extracellular stimuli produces an augment of ET-1 level in CLL cells. Finally, we demonstrated the fundamental role of NF-kB signalling pathway in promoting and maintaining ET-1 expression in CLL cells, both in basal conditions and after CD40 activation.

Bone marrow has already been described as an enrichment site for several antigen-specific T lymphocytes, but the presence of mould-specific T cells has never been investigated in the bone marrow. We have previously demonstrated that mould-specific T cells emerge in the peripheral blood of patients with invasive fungal infections (IFI) but tend to become undetectable after disease resolution. In seven patients with a history of IFI, we investigated the presence of mould-specific T cells secreting different cytokines in bone marrow and peripheral blood paired samples. The results showed that the frequencies of mould-specific T cells secreting the protective cytokine IFNγ are significantly higher in bone marrow (BM) and are mainly represented by CD8+ T lymphocytes with effector phenotype. A putative disappearance of such protective BM responses after myeloablative therapy could contribute to the increased risk of IFI in hematologic patients.

RNA interference (RNAi) has been suggested to represent a promising therapeutic approach in different disease settings. Primary effusion lymphoma (PEL) is a plasmablastic lymphoma consistently expressing B lymphocyte-induced maturation protein 1 (Blimp-1), a pivotal transcriptional regulator during

Mucorales-specific T cells were investigated in 28 hematologic patients during the course of their treatment. Three developed proven invasive mucormycosis (IM), 17 had infections of known origin but other than IM, and 8 never had fever during the period of observation. Mucorales-specific T cells could be detected only in patients with IM, both at diagnosis and throughout the entire course of the IM, but neither before nor for long after resolution of the infection. Such T cells predominantly produced IL-4, IFN-γ, IL-10, and to a lesser extent IL-17 and belonged to either CD4+ or CD8+ subsets. The specific T cells that produced IFN-γ were able to directly induce damage to Mucorales hyphae. None of the 25 patients without IM had Mucorales-specific T cells. Specific T cells contribute to human immune responses against fungi of the order Mucorales and could be evaluated as a surrogate diagnostic marker of IM.

Imatinib mesylate has been demonstrated to allow the emergence of T cells directed against chronic myeloid leukemia cells. A total of 10 Philadelphia chromosome–positive acute lymphoblastic leukemia patients receiving high-dose imatinib mesylate maintenance underwent long-term immunological monitoring (range, 2-65 months) of p190BCR-ABL–specific T cells in the bone marrow and peripheral blood. p190BCR-ABL–specific T lymphocytes were detected in all patients, more frequently in bone marrow than in peripheral blood samples (67% vs 25%, P < .01) and resulted significantly associated with lower minimal residual disease values (P < .001), whereas absent at leukemia relapse. Specific T cells were mainly effector memory CD8+ and CD4+ T cells, producing interferon-γ, tumor necrosis factor-α, and interleukin-2 (median percentage of positive cells: 3.34, 3.04, and 3.58, respectively). Cytotoxic subsets able to lyse BCR-ABL–positive leukemia blasts also were detectable. Whether these autologous p190BCR-ABL–specific T cells may be detectable under other tyrosine-kinase inhibitors, expanded ex vivo, and exploited for immunotherapy remains to be addressed.

Objectives: To describe the first in-depth analysis of both the T-cell responses against human herpesvirus-8 (HHV-8) and the HHV-8 viral load in 1 patient who developed iatrogenic HHV-8-associated-Kaposi's sarcoma (KS) following immunosuppressive treatment for undifferentiated arthritis and to review the literature on iatrogenic KS (IKS). Methods: T-cell responses against HHV-8 lytic and latent antigens were analyzed by ex vivo enzyme-linked immunospot (Elispot) and HHV-8 viral load was assessed by quantitative polymerase chain reaction, in sequential peripheral blood samples from a 55-year-old woman who developed skin/mucosal and visceral KS, while receiving treatment with cyclosporine, methotrexate, and methylprednisolone for undifferentiated arthritis. Results: KS may result from HHV-8 infection in patients undergoing immunosuppressive treatment for rheumatic diseases and this is the first case of IKS occurring in undifferentiated arthritis. A role for immune surveillance in the pathogenesis of IKS is supported by the observation of disease regression following discontinuation of immunosuppressive therapy. In a 4-year follow-up, we showed that variations of the virus-specific immune responses but not of the viral load correlated well with the disease course, characterized by 2 remission and subsequent relapse phases, following changes of immunosuppressive therapy. Conclusions: We have provided evidence of a clear-cut correlation between changes in immunologic markers of HHV-8 infection and the disease course of this viral associated tumor, concomitant with variations of immunosuppressive treatment. Thus, ex vivo enzyme-linked immunospot for HHV-8-specific T-cell responses represents a new tool for the clinical management of rheumatic patients with IKS. (C) 2009 Elsevier Inc. All rights reserved. Semin Arthritis Rheum 39:170-175 RI Rossi, Giulio/C-5576-2011

Nucleophosmin 1 (NPM1) gene mutations, resulting in aberrant cytoplasmic delocalization of NPM1 (NPMc+), are detected in about 30% of all de novo acute myeloid leukemia (AML) cases, and in 50–60% o...

We have read with great interest the report, recently appeared in the Journal, by Fazakas et al. [1], who described a case of a 65-year-old woman presenting with coexisting multicentric plasmacytic...

Epstein-Barr virus (EBV) is a γ herpesvirus well recognized to be involved in the development of human B (Hodgkin and non Hodgkin lymphomas) and NK/T cell lymphomas, either in the general population or in the immunosuppressed individuals. The human herpesvirus 8 (HHV-8) is another γ herpesvirus, recently recognized to be associated with the occurrence of rare B cell lymphomas and atypical lymphoproliferations, especially in the human immunodeficiency virus (HIV) infected subjects. Moreover, the human herpesvirus-6 (HHV-6), a β-herpesvirus, has been shown to be implicated in some non-malignant lymph node proliferations, such as the Rosai Dorfman disease and in a proportion of Hodgkin lymphoma cases. HHV-6 has a wide cellular tropism and it might play a role in the pathogenesis of a wide variety of human diseases, but given its ubiquity, disease associations are difficult to prove and its role in hematological malignancies is still controversial. The involvement of another β-herpesvirus, the human cytomegalovirus (HCMV), has not yet been proven in human cancer, even though recent findings have suggested its potential role in the development of CD4+ large granular lymphocyte (LGL) lymphocytosis. Here, we review the current knowledge on the pathogenetic role of HHV-8 and human β-herpesviruses in human lymphoproliferative disorders.

BCR–ABL-specific cytotoxic T cells in the bone marrow of patients with Ph + acute lymphoblastic leukemia during second-generation tyrosine-kinase inhibitor therapy

Clinical charts from 63 consecutive highly immunocompromised haematologic patients presenting with pulmonary nodular lesions on CT scan, classified as either probable or possible invasive fungal disease (IFD) according to the revised EORTC/MSG classification, were retrospectively studied. Histopathological analysis of lung tissues, available for 23 patients, demonstrated proven IFD in 17 cases (14 invasive aspergillosis and 3 invasive zygomycosis), diffuse alveolar damage in one and organising pneumonia (OP) in five cases. In the OP cases, three of which have been defined as probable IFD according to EORTC/MSG classification, extensive immunohistochemical, molecular and immunological analyses for fungi were negative. Our case descriptions extend the notion that OP may be encountered as a distinct histopathological entity in pulmonary nodular lesions in patients with leukaemia with probable/possible IFD.

A child with acute myeloid leukemia presented with multiple liver lesions mimicking hepatosplenic candidiasis during the neutropenic phase following the induction chemotherapy. All the available diagnostic tools showed repeatedly negative results, including galactomannan. An enzyme-linked immunospot (ELISPOT) assay showed a high number of Aspergillus -specific T cells producing interleukin-10 [TH2(IL-10)] and a low number of Aspergillus -specific T cells producing gamma interferon [TH1(IFN-γ)], revealing invasive aspergillosis (IA) before the confirmatory biopsy. A progressive skewing from the predominance of TH2(IL-10) to a predominance of TH1(IFN-γ) was observed close to the complete resolution of the infection and foreshadowed the outcome. The ELISPOT assay holds promise for diagnosing pediatric IA.

Unlike alpha- and beta-herpesviruses, human gamma-herpesviruses, including the Epstein-Barr virus (EBV) and the human herpesvirus-8 (HHV-8), are B lymphotropic viruses. Primary infection with EBV, in otherwise healthy subjects, causes a benign lymphoproliferative syndrome, the mononucleosis syndrome. However, several epidemiologic and biologic studies have shown a pathogenetic role of EBV in the development of human B cell lymphomas, both in immunocompetent and in immunosuppressed individuals. HHV-8 is the necessary etiologic agent of a lymph vascular tumor, the Kaposi sarcoma, but it is also implicated in the pathogenesis of rare B cell lymphoproliferative disorders, mainly occurring in the setting of immunosuppression. The aim of this review is to provide an updated description of the different strategies used by these two herpesviruses to influence B cell fate decisions. Both EBV and HHV-8 have evolved specific mechanisms in order to: (1) interact with the B cell developmental machinery; (2) allow infected B cells to escape from the control of the immune system; (3) affect the B cell cycle checkpoints; (4) mimic and influence B cellular proliferation and differentiation pathways. Understanding the mechanisms of herpesvirus induced B cell lymphoproliferation will provide the basis for novel treatment approaches in patients with EBV and HHV-8 related lymphomas.

To the Editor: Parvoviruses (PARV) 4 and 5 are 2 genotypes of a novel human parvovirus, with 92% nucleotide identity, identified in the plasma sample of a patient screened for acute HIV infection and in samples of manufactured plasma pools (1,2). Recently, PARV4 and PARV5 were identified in blood samples from 3 of 26 cadavers from the United Kingdom, all of whom were positive for hepatitis C virus RNA and had a history of intravenous drug use (3). PARV4/5 were also found in bone marrow (BM) and lymphoid tissues from 17 of 24 HIV-positive cadavers from Scotland (4) and in BM aspirates from 16 of 35 Italian patients with AIDS (5). Little or no information is available about the epidemiology and clinical correlates of infection with these novel viruses. To provide insights into their pathogenic potential in vivo, we assessed the frequency of PARV4/5 viremia in healthy patients, transplant patients, and those with suspected viral disease. We performed a retrospective molecular study for the presence of PARV4/5 sequences in 4 groups of 417 Italian HIV-negative persons. Group 1 consisted of 100 blood donors recruited from the Transfusion Centre of Modena (northern Italy); group 2, 84 patients with hematologic diseases showing clinical signs of viral etiology but negative results for the most common viruses (herpesviruses, adenovirus, hepatitis virus, and coxsackie virus). For both of these groups, DNA was extracted for analysis from serum specimens and peripheral blood mononuclear cells (PBMCs). Groups 3 and 4 comprised recipients of kidney and allogeneic BM/peripheral blood stem cell (PBSC) transplants, for which DNA was extracted from serum specimens collected at 6 and 12 months, respectively, after transplantation. The nested PCR method was used to amplify a shared sequence of PARV4 and its variant PARV5 and was specific for the open reading frame 1. First step PCR was performed as previously described (2) with a sensitivity of 1–10 copies, on 1 μg PBMC DNA and on one fifth of DNA extracted from 0.25 mL of serum. Primers for second round PCR were PV4NS1Fn2 (5′-GTTGATGGYCCTGTGGTTAG-3′) and PV4NS1Rn2 (5′-CCTTTCATATTCAGTTCCTGTTCAC-3′). All positive results were confirmed by direct sequencing. We found 3 positive case-patients, including 2 renal transplant recipients and 1 patient with a suspected viral disease; none of the blood donors tested positive on single-round PCR. On nested PCR, 1 blood donor had positive results; the positivity rate did not increase in the other groups (Table). In the first 2 groups, PARV4/5 sequences were detected only in the serum samples, not in the PBMCs collected at the same time. These sequences suggest that PBMCs are not a major site of viral replication. Similar to B19 infection, which is rarely reactivated in the setting of BM/PBSC transplantation (6,7), none of the BM/PBSC transplant patients were PARV4/5 positive. The detection of PARV4/5 sequences in the serum collected at 12 months after transplantation was not associated with the occurrence of any symptoms in the 2 renal recipients. Of note, the available serum samples collected from both recipients before transplantation, and at 6 and 24 months after transplantation, were PARV4/5 negative, which suggests that asymptomatic PARV4/5 infection may transiently occur after solid organ transplantation or may be acquired throughout transfusion or transplantation. Similarly, the rate of B19 infection in solid organ transplant recipients is low (1.4%–1.8%), and most B19 DNA–positive patients remain asymptomatic (8,9). Table Analysis of 417 patients tested for parvoviruses 4/5 by PCR* PARV4/5 sequences were detected in the serum collected from 1 patient affected with Wegener granulomatosis. This patient was under long-term treatment with steroids, concomitant with the development of a clinical syndrome for which a viral cause was suspected, including fever, severe anemia, a histologic-examination–proven postinfectious glomerulonephritis, and eryhtroid hypoplasia, with dsyserythropoiesis and dismegakaryopoiesis on BM examination. Serologic and molecular tests for the most common viruses, including B19, were negative and the patient died of multiple organ failure 1 month later. Single-cell PCR performed on the DNA extracted from isolated BM erythroid and myeloid progenitors in the formalin-fixed, paraffin-embedded BM tissue biopsy specimens, collected 2 days before death and at autopsy, were PARV4/5 negative. While the PARV4/5 viremia, in the absence of other known viral agents, suggests a possible contribution of this novel parvovirus to the patient’s clinical syndrome, the absence of the virus in the BM cells suggests that its in vivo tropism may markedly differ from that of B19. In conclusion, although the frequency of PARV4/5 viremia is very low in the general Italian population, it is slightly higher in certain subgroups of iatrogenically immunosuppressed patients and it is not clear to which extent immunosuppression enhances viral reactivation and/or primary infection. Failure to detect PARV4/5 DNA in all but 4 study patients does not necessarily indicate a rarity of past viral exposure or infection in transplant patients or indeed in the general population. Further studies are needed to confirm a possible pathogenic role of PARV4/5 infection

Abstract 3229 Introduction: Several studies have reported that different components of fungi of the genera Aspergillus spp may induce protective T-cell responses in either mouse models of invasive aspergillosis (IA) or in human healthy subjects. We evaluated the occurrence of Aspergillus-specific T-cell responses to different Aspergillus recombinant antigens in patients with proven IA, during the course of the IA, to identify the antigens most frequently targeted by protective immune responses. We characterized phenotypically and functionally such specific T cells. Finally, from peripheral blood (PB) samples of the same IA proven patients, also collected during the active infection phase, we sought to expand such Aspergillus-specific T cells. Methods: 15 patients with proven IA, according to the EORTC/MSG criteria, have been enrolled into the study. Specific immune responses producing interleukin-10 (IL-10), interferon-gamma (IFN-γ), IL-4 and IL-17A were detected and characterized by enzyme linked immunospot (ELISpot) assay and cytokine secretion assay (CSA), in all the patients, during the entire course of the IA. The recombinant antigens used were GEL1p, CRF1p, PEP1p, SOD1p, α1–3glucan, β1–3glucan, and galactomannan (GM). Cytotoxicity has been investigated by means of the colorimetric assay with (2,3-bis[2-methoxy-4-nitro-5-sulfophenyl]2H-tetrazolium-5-carboxyanilide) sodium salt plus coenzyme Q0 (XTT assay). Aspergillus-specific T cells were obtained by culturing PB mononuclear cells with a mixture containing PEP1p, GEL1p, α1–3 glucan and β1–3 glucan. The infection course were divided into 4 phases, defined from t1 to t4, each of fifteen days interval, starting from the radiological diagnosis of IA. Results: Aspergillus-specific T cells producing either IL-10 or IFN-γ were detected to all the antigens, but GM. The number of antigens targeted by IFN-γ producing specific T cells progressively increased along the course of IA, being such protective responses to 3 out of 7 antigens at t1 and to 6 out of 7 antigens at t4. At t1, IFN-γ producing specific T cells were only detected to GEL1p, α1–3 glucan and β1–3 glucan. GEL1p and α1–3 glucan resulted the antigens most constantly targeted by IFN-γ producing specific T cells, persisting the responses to these antigens in all the phases of IA. No Aspergillus-specific T cells producing IL-4 to any antigens were detected by the ELISpot assay. Aspergillus-specific T cells producing IL-17A were detected in only one out of 15 patients, and targeted CRF1p. Specific T cells to GM and specific T cells producing IL-4 to all the antigens could be shown only by CSA, suggesting that they are present only at very low frequencies during the infection. After 13-day cultures, Aspergillus-specific T cells were expanded from five out of five patients. The specific T cells tested for lytic activity included a median of 95.8% CD3+ cells, either CD4+ or CD8+ T cells, and showed a median lytic activity of 9.45% either at 3/1 or at 5/1 effector/target cells ratios. Conclusions: In patients with IA, protective immune responses may be detected since the onset and increase during the infection. At the onset of IA, specific T cells producing IFN-γ target antigens involved in the cell wall biosynthesis of Aspergillus. On the other hand, at the same phase, specific protective immune responses to CRF1p, PEP1p, and SOD1p, which are all putative virulence factors for Aspergillus, are absent. Aspergillus-specific T cells may be expanded by a mixture of antigens, even in the course of IA and are able to directly kill fungal hyphae. The above mentioned antigens and the corresponding protective T cells may be exploited for therapeutic strategies of either vaccine or autologous cytotoxic cell infusions in patients at high risk for IA. Disclosures: Luppi: MSD; GILEAD: Research Funding.

Introduction: In lymphoid organs, nurse-like cells (NLCs) show properties of tumor-associated macrophages with a M2-like phenotype, associated to prominent immunosuppressive functions, and play a crucial role in CLL survival. Ibrutinib is a potent inhibitor of BTK and ITK kinases and is able to counteract the microenvironmental-derived pro-survival effects in CLL cells. One of the main effects of ibrutinib treatment is attenuated retention and homing of CLL cells to tissue compartments, which ultimately leads to mobilization of CLL cells from microenvironmental niches into the peripheral blood. Aim: Here, we investigated whether ibrutinib treatment may have an effect on the immunosuppressive properties of NLCs. Methods: NLCs were generated in complete medium after 12 days of in vitro culture of CLL-PBMCs. Cell activation status, cell surface markers, real time PCR and functional studies were performed after 1h or 24h of ibrutinib treatment, to test whether ibrutinib influenced M1 or M2-polarization of NLCs. Results: We first observed that, after ibrutinib treatment, the activation status and viability of NLCs were not affected, the morphology of NLCs in vitro analyzed by flow-cytometric FCS and SSC plots was not modified and the number of NLCs generated after 12 days of culture was preserved. Furthermore, treatment with ibrutinib stimulated the expression of the M2-associated markers hemoglobin scavenger receptor CD163 and the mannose receptor C type 1 CD206, and induced expression of the monocyte differentiation antigen CD14. At the gene expression level, ibrutinib induced strong expression of genes involved in M2 polarization such as CD163 (293%, p Conclusions: Collectively, these preliminary data provide new insights into the effects of ibrutinib treatment on the modulation of immune elements in CLL tissue microenvironment. Noteworthy, our data demonstrate that ibrutinib further promotes M2-polarization features of NLCs, suggesting that this drug not only has an effect on the CLL clone but also extensively influences the cellular components of the CLL microenvironment, whether these effects may be related to ibrutinib-resistance warrants further investigations. Disclosures Burger: Boehringer Ingelheim Pharma: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Noxxon: Membership on an entity's Board of Directors or advisory committees; Portola Pharmaceuticals: Research Funding; Gilead: Research Funding; Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding. Marasca:Janssen: Honoraria, Other: support for travel to congresses.