Cell Lymphoproliferative Disease Research Articles

Platinum Complexes And Their Anti-Tumour Activity Against Chronic Lymphocytic Leukaemia Cells

Abstract Since the discovery of the antitumor activity of cisplatin by Rosenberg and co-workers, the use of metal complexes in cancer treatment has caused a huge interest. Today, platinum-based drugs are part of standard chemotherapy in the management of a variety of ca ncers, germ cell tumours, sarcomas, and lymphomas. Unfortunately, toxicity and drug resistance are major obstacles to wider clinical application of these drugs. Their use is greatly limited by severe side effects such as nephrotoxicity, ototoxicity, and neurotoxicity. Although cisplatin is one of the most successful anticancer drugs to date, its biochemical mechanism of action is still unclear. Cisplatin is generally accepted as having the ability to interact with the purine bases on the DNA, causing DNA damage, interfering with DNA repair mechanisms, and subsequently inducing apoptosis in cancer cells. Chronic lymphocytic leukaemia is a neoplastic B cell lymphoproliferative disease characterized by a highly variable clinical course. Clinical stage at the diagnosis and biological prognostic factors are the important predictors for survival. The Rai and Binet staging systems describe three major prognostic subgroups. Commonly used prognostic biomarkers in chronic lymphocytic leukaemia can be divided into genotypic, DNA-level changes and phenotypic, expression-level changes. For chronic lymphocytic leukaemia, substantial progress in therapy has not been made over the past 40 years. The main goal of future scientific research is to find new platinum complexes that have better efficacy in cancer treatment, the ability to be administered orally, without developing a cancer-drug resistance, and reduced toxic side effects.

Applied Protein and Molecular Techniques for Characterization of B Cell Neoplasms in Horses.

Mature B cell neoplasms cover a spectrum of diseases involving lymphoid tissues (lymphoma) or blood (leukemia), with an overlap between these two presentations. Previous studies describing equine lymphoid neoplasias have not included analyses of clonality using molecular techniques. The objective of this study was to use molecular techniques to advance the classification of B cell lymphoproliferative diseases in five adult equine patients with a rare condition of monoclonal gammopathy, B cell leukemia, and concurrent lymphadenopathy (lymphoma/leukemia). The B cell neoplasms were phenotypically characterized by gene and cell surface molecule expression, secreted immunoglobulin (Ig) isotype concentrations, Ig heavy-chain variable (IGHV) region domain sequencing, and spectratyping. All five patients had hyperglobulinemia due to IgG1 or IgG4/7 monoclonal gammopathy. Peripheral blood leukocyte immunophenotyping revealed high proportions of IgG1- or IgG4/7-positive cells and relative T cell lymphopenia. Most leukemic cells lacked the surface B cell markers CD19 and CD21. IGHG1 or IGHG4/7 gene expression was consistent with surface protein expression, and secreted isotype and Ig spectratyping revealed one dominant monoclonal peak. The mRNA expression of the B cell-associated developmental genes EBF1, PAX5, and CD19 was high compared to that of the plasma cell-associated marker CD38. Sequence analysis of the IGHV domain of leukemic cells revealed mutated Igs. In conclusion, the protein and molecular techniques used in this study identified neoplastic cells compatible with a developmental transition between B cell and plasma cell stages, and they can be used for the classification of equine B cell lymphoproliferative disease.

Basophil activation by mosquito extracts in patients with hypersensitivity to mosquito bites

Hypersensitivity to mosquito bites (HMB) is a cutaneous disorder belonging to the group of Epstein–Barr virus (EBV)-associated T/natural killer (NK)-cell lymphoproliferative diseases, and is primarily mediated by EBV-infected NK cells. It is characterized by intense local skin reactions accompanied by general symptoms after mosquito bites, and infiltration of EBV-infected NK cells into the bite sites. However, the mechanisms underlying these reactions have not been fully examined. We recently described the activation of circulating basophils by mosquito extracts in vitro in a patient with HMB. To further investigate this finding, we studied four additional patients with HMB. All patients showed typical clinical features of HMB after mosquito bites and they had NK lymphocytosis and high peripheral blood EBV DNA loads. We found evidence of EBV infection in NK cells through in situ hybridization that detected EBV-encoded small RNA-1, and flow cytometry showed HLA-DR expression on almost all NK cells. Basophil activation tests with the extracts of epidemic mosquitoes Culex pipiens pallens and Aedes albopictus showed positive responses to one or both extracts in all samples from patients with HMB, suggesting the presence of mosquito antigen-specific IgE and its binding to basophils. In particular, the extract of Aedes albopictus was able to activate basophils in all available patient samples. These results indicate that basophils and/or mast cells activated by mosquito bites may be involved in initiation and development of severe skin reactions to mosquito bites in HMB.

Targeting neoplastic B cells and harnessing microenvironment: the "double face" of ibrutinib and idelalisib.

Tyrosine kinase inhibitors (TKIs) targeting signaling molecules downstream B cell receptor (BCR) are powerfully spreading in the therapeutic landscape of B cell lymphoproliferative disease, due to a manageable toxicity profile and encouraging clinical effectiveness. In particular, ibrutinib, previously called PCI-32765, is a potent inhibitor of Bruton tyrosine kinase (Btk), recently approved for the treatment of relapsed mantle cell lymphoma (MCL) and chronic lymphocytic leukemia (CLL). Moreover, idelalisib (formerly GS-1101 and CAL-101) is a selective reversible inhibitor of the p110δ isoform of phosphoinositol 3 kinase (PI3K) approved for the treatment of patients with relapsed follicular lymphoma (FL) and CLL. These agents directly affect the neoplastic clone, disrupting the supportive platform provided by BCR signaling cascade and by other microenvironmental mutualistic interactions, and also interfering with chemokine gradients and adhesive properties of neoplastic B cells. In the present review, we describe the clinical efficacy of ibrutinib and idelalisib in CLL and B cell non-Hodgkin lymphoma (B-NHL), then focusing on the mode of action (MOA) of these TKIs towards the neoplastic B cell compartment. At last, the review would further expand the view on potential additional targets of ibrutinib and idelalisib belonging to other microenvironmental cellular elements.

Use of serial assessment of disease severity and liver biopsy for indication for liver transplantation in pediatric Epstein-Barr virus-induced fulminant hepatic failure.

The decision to perform liver transplantation (LT) in patients with Epstein-Barr virus (EBV)-induced fulminant hepatic failure (FHF) relies on a precise assessment of laboratory and pathological findings. In this study, we analyzed clinical and laboratory data as well as the pathological features of the liver in order to evaluate the pathogenesis and the need for LT in 5 patients with EBV-induced FHF. According to the King's College criteria, the Acute Liver Failure Early Dynamic (ALFED) model, and the Japanese criteria (from the Acute Liver Failure Study Group of Japan), only 1 patient was considered to be a candidate for LT. However, explanted liver tissues in 3 cases exhibited massive hepatocellular necrosis together with diffuse CD8-positive T cell infiltration in both the portal area and the sinusoid. EBV was detected in the liver, plasma, and peripheral blood mononuclear cells (PBMNCs). In 2 cases indicated to be at moderate risk by the ALFED model, liver biopsy showed CD8-positive and EBV-encoded RNA signal-positive lymphocytic infiltration predominantly in the portal area, but massive hepatocellular necrosis was not observed. These patients were treated with immunosuppressants and etoposide under the diagnosis of EBV-induced hemophagocytic lymphohistiocytosis or systemic EBV-positive T cell lymphoproliferative disease of childhood. EBV DNA was detected at a high level in PBMNCs, although it was negative in plasma. On the basis of the pathological analysis of the explanted liver tissues, LT was proposed for the restoration of liver function and the removal of the EBV-infected lymphocytes concentrated in the liver. Detecting EBV DNA by a quantitative polymerase chain reaction in plasma and PBMNCs was informative. An accurate evaluation of the underlying pathogenesis is essential for developing a treatment strategy in patients with EBV-induced FHF.

Clonal CD8+ T Lymphocytic Proliferation and Karyotypical Abnormalities in an EBV Associated Hemophagocytic Lymphohistiocytosis.

EBV associated hemophagocytic lymphohistiocytosis and EBV-positive T cell lymphoproliferative disease of childhood share many histologic and clinical features, which sometimes makes it very difficult to render a definitive diagnosis. In this report, we present a 16-year-old male who developed symptoms clinically consistent with EBV associated hematophagocytic lymphohistiocytosis including fulfilling most of HLH diagnostic criteria and responding promptly to HLH targeted therapy. However, histologic and cytogenetics features of this case are very concerning for EBV-positive T cell lymphoproliferative disease of childhood. This case demonstrates an ambiguous boundary of these two disease entities and emphasizes the importance of comprehensive evaluation and clinical correlation with cases suspicious of EBV driven hemophagocytic or lymphoproliferative process.

Modeling EBV infection and pathogenesis in new-generation humanized mice.

The development of highly immunodeficient mouse strains has allowed the reconstitution of functional human immune system components in mice. New-generation humanized mice generated in this manner have been extensively used for modeling viral infections that are exclusively human tropic. Epstein–Barr virus (EBV)-infected humanized mice reproduce cardinal features of EBV-associated B-cell lymphoproliferative disease and EBV-associated hemophagocytic lymphohistiocytosis (HLH). Erosive arthritis morphologically resembling rheumatoid arthritis (RA) has also been recapitulated in these mice. Low-dose EBV infection of humanized mice results in asymptomatic, persistent infection. Innate immune responses involving natural killer cells, EBV-specific adaptive T-cell responses restricted by human major histocompatibility and EBV-specific antibody responses are also elicited in humanized mice. EBV-associated T-/natural killer cell lymphoproliferative disease, by contrast, can be reproduced in a distinct mouse xenograft model. In this review, recent findings on the recapitulation of human EBV infection and pathogenesis in these mouse models, as well as their application to preclinical studies of experimental anti-EBV therapies, are described.

Epstein-Barr virus-positive T/NK-cell lymphoproliferative disorders.

Epstein–Barr virus, a ubiquitous human herpesvirus, can induce both lytic and latent infections that result in a variety of human diseases, including lymphoproliferative disorders. The oncogenic potential of Epstein–Barr virus is related to its ability to infect and transform B lymphocytes into continuously proliferating lymphoblastoid cells. However, Epstein–Barr virus has also been implicated in the development of T/natural killer cell lymphoproliferative diseases. Epstein–Barr virus encodes a series of products that mimic several growth, transcription and anti-apoptotic factors, thus usurping control of pathways that regulate diverse homeostatic cellular functions and the microenvironment. However, the exact mechanism by which Epstein–Barr virus promotes oncogenesis and inflammatory lesion development remains unclear. Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases often have overlapping clinical symptoms as well as histologic and immunophenotypic features because both lymphoid cell types derive from a common precursor. Accurate classification of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases is a prerequisite for appropriate clinical management. Currently, the treatment of most T/natural killer cell lymphoproliferative diseases is less than satisfactory. Novel and targeted therapies are strongly required to satisfy clinical demands. This review describes our current knowledge of the genetics, oncogenesis, biology, diagnosis and treatment of Epstein–Barr virus-associated T/natural killer cell lymphoproliferative diseases.

Histological Characteristics of Ataxia Telangiectasia Associated Lymphoproliferative Diseases. Results of the French Registry of Primary Immune Deficiencies

IntroductionAtaxia-telangiectasia (A-T) is a rare autosomal recessive disorder associated with mutations in the ATMgene and characterized by cerebellar ataxia, telangiectasia, immune defect, and a high incidence of lymphoid and solid cancers. We conducted a retrospective study of the patients with AT enrolled in the registry of the French National Reference Center for Primary Immune Deficiencies, in order to describe the incidence, subtypes, and outcomes of cancer and mainly of lymphoproliferative diseases (LPD) occurring in AT. Most of the LPD of this study were centrally reviewed by 2 expert hematopathologists.Patients & ResultsSixty nine patients with cancers were identified among the 279 patients with AT of our cohort. Eight patients developed carcinomas, 8 acute leukemias, 3 T-cell prolymphocytic leukemias and 50 developed lymphomas. Among the lymphomas, 12 were classical Hodgkin’s lymphomas (cHL), and 38 high-grade non-Hodgkin lymphomas (NHL, 26 of B-cell type, 4 of T-cell type, and 8 not phenotyped). We obtained a centralized histopathology review in 31 cases classified by pathology reports as cHL (n=6) and high-grade NHL (n=25). Cases were reviewed according to the WHO classification by H&E staining and immunohistochemistry. The presence of EBV was analyzed using antibodies to LMP and in situ hybridization for EBER. Concordance between the diagnosis established on pathology reports and the centralized review was excellent. All 6 cases of cHL were confirmed by the pathology review. The 25 cases initially diagnosed as high-grade NHL based on pathology reports fell into several WHO classification categories. Six corresponded to Burkitt’s lymphomas (BL) and 12 to diffuse large B-cell lymphomas (DLBCL). Among the latter, 10 could be further classified according to cell-of-origin by the Hans algorithm as germinal center (GC, 2) and non-GC (8). Seven cases displayed polymorphic histological features reminiscent of post-transplant lymphoproliferative disorders (LPD), 5 polymorphic B cell LPD (pLPD), 1 with features of infectious mononucleosis (IM), another with features of plasmacytic hyperplasia LPD. EBV could be evaluated in 28 cases. All 6 cHL, 4 out of 11 DLBCL, all 5 pLPD, and the case of IM-like LPD were EBV positive by LMP and/or EBER staining. The 5 cases of BL that were evaluated were all EBV negative. Median age at diagnosis was 7.8 years [range 3 – 24], 14.9 [5.8 – 17.1], 12.2 [5.4 – 29] and 11 [6.3 – 17.7] for pLPD, cHL, BL and DLBCL respectively (p=ns). Median survival after diagnosis of lymphoma was 35, 8.6, 6 and 8 months for pLPD, cHL, BL and DLBCL respectively (p=ns). ATM mutation analysis was available for 20 cases (8 hypomorphic mutations, 12 loss-of-function mutations). There were no differences in age at diagnosis of lymphoma or survival according to the ATM mutation class or the EBV status.ConclusionB-cell malignancies including cHL and B-cell NHL are the most frequent malignancies in A-T and can be further classified as DLBCL, BL and cases with polymorphic features resembling post-transplant LPD. EBV seems to be associated with all cHL, approximately 50% of DLBCL and polymorphic LPD, but not with BL. The majority of DLBCL are non-GC type by immunohistochemistry. On this series of 31 patients, ATM mutation type was not associated with differences in type of lymphoma or outcome. DisclosuresNo relevant conflicts of interest to declare.

Targeted Activation of Human Vγ9Vδ2-T Cells Controls Epstein-Barr Virus-Induced B Cell Lymphoproliferative Disease

Epstein-Barr virus-induced lymphoproliferative disease (EBV-LPD) after transplantation remains a serious and life-threatening complication. Herein we showed that the aminobisphosphonate pamidronate-expanded human Vγ9Vδ2-T cells efficiently killed EBV-transformed autologous lymphoblastoid B cell lines (EBV-LCL) through γ/δ-TCR and NKG2D receptor triggering and Fas and TRAIL engagement. By inoculation of EBV-LCL in Rag2(-/-)γc(-/-) mice and humanized mice, we established lethal EBV-LPD with characteristics close to those of the human disease. Adoptive transfer of pamidronate-expanded Vγ9Vδ2-T cells alone effectively prevented EBV-LPD in Rag2(-/-)γc(-/-) mice and induced EBV-LPD regression in EBV(+) tumor-bearing Rag2(-/-)γc(-/-) mice. Pamidronate treatment inhibited EBV-LPD development in humanized mice through selective activation and expansion of Vγ9Vδ2-T cells. This study provides proof-of-principle for a therapeutic approach using pamidronate to control EBV-LPD through Vγ9Vδ2-T cell targeting.

Hypersensitivity to mosquito bites as the primary clinical manifestation of an Epstein–Barr virus infection

Hypersensitivity to mosquito bites (HMB) is a rare disease characterized by intense local skin reactions with general symptoms, such as high fever and regional lymphadenopathy after mosquito bites. Epstein-Barr virus (EBV) chronic infection and NK cell lymphoproliferative disease have been reported first in diagnosed HMB patients. Here, we present the case of a 6-year-old girl with 2 months' history of bullae and necrotic skin lesions, accompanied by a high temperature, visual hallucinations, and liver dysfunction after mosquito bites. A histopathologic examination of the skin lesion showed vasculitis and EBV infection. We could not detect any findings of hematologic malignancies or NK cell proliferative disease in the patient. Clinicians should closely evaluate HMB patients for possible development of lymphoproliferative status or hematologic malignant disorders.

Hepatitis C infection and lymphoproliferative disease: accidental comorbidities?

Chronic hepatitis C virus (HCV) infection has been associated with liver cancer and cirrhosis, autoimmune disorders such as thyroiditis and mixed cryoglobulinema, and alterations in immune function and chronic inflammation, both implicated in B cell lymphoproliferative diseases that may progress to non-Hodgkin lymphoma (NHL). HCV bound to B cell surface receptors can induce lymphoproliferation, leading to DNA mutations and/or lower antigen response thresholds. These findings and epidemiological reports suggest an association between HCV infection and NHL. We performed a systematic review of the literature to clarify this potential relationship. We searched the English-language literature utilizing Medline, Embase, Paper First, Web of Science, Google Scholar, and the Cochrane Database of Systematic Reviews, with search terms broadly defined to capture discussions of HCV and its relationship with NHL and/or lymphoproliferative diseases. References were screened to further identify relevant studies and literature in the basic sciences. A total of 62 reports discussing the relationship between HCV, NHL, and lymphoproliferative diseases were identified. Epidemiological studies suggest that at least a portion of NHL may be etiologically attributable to HCV, particularly in areas with high HCV prevalence. Studies that showed a lack of association between HCV infection and lymphoma may have been influenced by small sample size, short follow-up periods, and database limitations. The association appears strongest with the B-cell lymphomas relative to other lymphoproliferative diseases. Mechanisms by which chronic HCV infection promotes lymphoproliferative disease remains unclear. Lymphomagenesis is a multifactorial process involving genetic, environmental, and infectious factors. HCV most probably have a role in the lymphomagenesis but further study to clarify the association and underlying mechanisms is warranted.

Plantar Keratoderma ile Prezente Olan Bir Akral Pitriyazis Likenoides Kronika Olgusu

Pityriasis lichenoides chronica (PLC) is a rare papulosquamous dermatosis with a relapsing and remitting course. It has been proposed that PLC is a clonal T cell lymphoproliferative disease triggered by an antigenic stimulus. Although the infectious agents and drugs are the possible etiopathological factors, the etiology of PLC still remains unclear. PLC is usually characterized by recurrent crops of erythematous-brown papules predominantly localized on trunk and proximal extremities. Atypical presentations of PLC with unusual sites of the involvement have been described rarely so far. Notably, a significant number of these presentations are acral or segmental variants. Here, to our knowledge, we report the first case of acral PLC presenting as plantar keratoderma.

Umbilical Cord Blood as an Alternative Source of Reduced-Intensity Hematopoietic Stem Cell Transplantation for Chronic Epstein-Barr Virus–Associated T or Natural Killer Cell Lymphoproliferative Diseases

Chronic Epstein-Barr virus–associated T/natural killer cell lymphoproliferative diseases represented by chronic active Epstein-Barr virus infection are lethal but are curable with several courses of chemotherapy and allogeneic hematopoietic stem cell transplantation (HSCT). Recently, we reported that reduced-intensity conditioning (RIC) provided better outcomes than myeloablative conditioning because RIC was less toxic. However, it was unclear whether cord blood transplantation (CBT) works in the context of RIC. We retrospectively analyzed 17 patients who underwent RIC followed by bone marrow transplantation (RIC-BMT) and 15 patients who underwent RIC followed by CBT (RIC-CBT). The representative regimen was fludarabine and melphalan based. The overall survival rates with RIC-BMT and RIC-CBT were 92.9% ± 6.9% and 93.3% ± 6.4%, respectively (P = .87). One patient died of lung graft-versus-host disease after RIC-BMT, and 1 patient died of multiple viral infections after RIC-CBT. Although cytotoxic chemotherapy was also immunosuppressive and might contribute to better donor cell engraftment after RIC-HSCT, the rate of engraftment failure after RIC-CBT was still higher than that after RIC-BMT (not significant); however, patients who had experienced graft failure were successfully rescued with a second HSCT. Unrelated cord blood can be an alternative source for RIC-HSCT if a patient has no family donor.

Are regimens containing rituximab effective in the initial treatment of Epstein–Barr virus-positive natural killer cell lymphoproliferative disease-associated hemophagocytic lymphohistiocytosis?

The outcome for patients with Epstein–Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) has improved significantly since the introduction of HLH-94 type immunochemotherapy [1]; however, treatment of EBV-HLH remains difficult in patients with chronic active EBV infection (CAEBV), a form of T or natural killer (NK) cell lymphoproliferative disease (LPD). [2, 3]. Although rituximab is effective as a pre-emptive B celldirected therapy for patients with XLP1-related EBV-HLH or severe EBV-HLH, in which EBV resides within B cells, [4–7] it has been thought to be inapplicable to Asian EBVHLH patients harboring EBV-infected T or NK cells. Here, testing the hypothesis that EBV may initially reside in B cells and may continue to produce virus particles and infect T or NK cells, we employed a combination of rituximab and HLH-94 type immunochemotherapy in the initial treatment of a 64-year-old Japanese male with EBV-NKLPD-associated HLH. The patient was referred to us with fever of unknown etiology. He had been suffering from influenza A infection and had remained febrile for nearly two weeks. His past history showed that the patient had suffered an episode of fever of unknown origin five months earlier, which had been associated with high serum IgG levels; therefore, one of the referring physicians suspected collagen disease, although no definitive diagnosis was made. On admission, the patient was febrile ([39.0 C) and suffering from diarrhea. Computed tomography revealed splenomegaly, but there was no evidence of adenopathy. Blood analysis revealed the following: WBC, 3,000/lL; Hb, 10.8 g/dL; platelet count, 71,000/lL; serum aspartate aminotransferase, 225 U/L; alanine aminotransferase, 116 U/L; lactate dehydrogenase, 1,050 U/L; total bilirubin, 1.6 mg/dL, total protein, 8.2 g/dL; albumin, 2.6 g/dL; BUN, 22.7 mg/dL; creatinine, 1.36 mg/dL; CRP, 7.23 mg/dL; ferritin, 17,282 ng/mL; sIL-2R, 14,700 U/mL; b-2-microglobulin, 12.6 mg/L; total cholesterol, 78 mg/dL; IgG, 4,116 mg/dL; IgA, 337 mg/dL; IgM, 68 mg/dL; anti-nuclear antibodies (ANA), [ 2,560; anti-DNA antibodies, \ 7; plasma fibrinogen, 207 mg/dL; and D-dimer, 42.7 lg/mL. In terms of hypergammaglobulinemia, the kappa/lambda ratio was 1.2 and neither M-protein nor Bence Jones protein was positive. No specific collagen disease was identified. The clinical features and laboratory data were compatible with the diagnostic criteria for HLH. The patient was diagnosed provisionally with collagen disease-related HLH and treated with oral prednisolone (PSL 30 mg/day). However, the high fever continued and he developed severe coagulopathy associated with a marked reduction in platelet count (21,000/lL), fibrinogen (\50 mg/dL) and anti-thrombin III (AT-3; 63 %) levels; therefore, he received gabexate S. Imashuku (&) N. Kudo Division of Hematology, Takasago-seibu Hospital, 1-10-41 Nakasuji, Takasago 676-0812, Japan e-mail: shinim95@mbox.kyoto-inet.or.jp

Bone marrow necrosis as clinical presentation of plasmablastic lymphoma in an AIDS patient: First case reported and literature review

Patients with HIV/AIDS disease are at high risk of developing non-Hodgkin lymphoma (NHL) which is included as anAIDS-defining illness. Plasmablastic lymphoma (PBL) most frequently presents in the oral cavity and generally inpatients with HIV infection. Extra-oral PBL is a rare tumor but with a similar capability to local invasion and rapiddissemination to extra-oral sites. Bone marrow necrosis (BMN) associated with high grade B cell lymphoproliferative disease is a rare condition that should be suspected in HIV-infected patients with unexplained fever and cytopenias. Herewe describe the first case of BMN caused by a high grade NHL diagnosis as PBL in an AIDS patient.

Clinical features and laboratory findings of adult Epstein-Barr virus associated T/NK lymphoproliferative disease

The aim of this study was to analyze the clinical features and laboratory findings of adult Epstein-Barr virus associated T/NK cell lymphoproliferative disease (EBV+T/NK-LPD) and to investigate the early diagnosis and prognosis of EBV+T/NK-LPD. The clinical data of 19 adult patients with EBV+T/NK-LPD were retrospectively analyzed. The results indicated that there were 11 males and 8 females. The median age was 32 years (range: 20-70 years). The average duration from onset of symptoms to diagnosis was 3.5 months. The median survival time was 2.5 months. Unkown fever, hepatosplenomegaly, liver dysfunction and interstitial pneumonia were the main clinical features. High levels of β2-MG, LDH, TNF, IL-6 and significantly increased EBV-DNA level (median level > 10(6) copies/ml) were occurred in all the patients. Cytopenia was seen in 18 cases. Morphologically, atypical large granular lymphocytes and hemophagocytosis were common in bone marrow smears. Deletion of CD5 or CD7 were frequently observed in T/NK lymphocytes in bone marrow cells by flow cytometry. Bone marrow biopsy showed atypical lymphocyte interstitial infiltrated in 10 cases, while a few large cells infiltrated in 6 cases. Immunohistochemistry showed the expression of CD3(+)CD56(+) were seen in 2 cases, CD3(+)CD8(+) in 11 cases and CD3(+)CD4(+) in 3 cases. TIA-1 and EBER were positive in all biopsy specimens. Three cases underwent biopsy of lymph nodes showed reactive proliferations of lymphocytes. All the patients died of multiorgan failure. It is concluded that the fever, hepatosplenomegaly are the most common clinical features in adult EBV+T/NK-LPD, the bone marrow infiltration of EBV-infected T/NK lymphocytes and significantly increased EBV-DNA level can be observed in all cases, the clinical outcome of this disease is poor, these clinical and experimental features can be served as a reliable marker for the timely diagnosis of adult EBV+T/NK-LPD.

Epstein-Barr virus-associated lymphoid malignancies: the expanding spectrum of hematopoietic neoplasms.

Ubiquitous Epstein-Barr virus (EBV) infects not only B cells but also T and NK cells, and is associated with various lymphoid malignancies. The spectrum of EBV-associated lymphoid malignancies is expanding from Burkitt lymphoma to the newly defined systemic EBV+ T cell lymphoproliferative disease of childhood and hydroa vacciniforme-like lymphoma. However, some EBV-associated malignancies are not defined well and overlap other diseases. Furthermore, the role of EBV in tumorigenesis of lymphoid malignancies is still not clear. Further studies are necessary to clarify the pathogenesis of EBV-associated lymphoid malignancies for a better classification of each disease and for the establishment of effective treatment.

MiRNA Signature of Mouse Helper T Cell Hyper-Proliferation

Helper T cells from a mutant mouse model, LAT Y136F, hyper-proliferate and cause a severe lymphoproliferative disease that kills the mice by six months of age. LAT Y136F mice carry a tyrosine to phenylalanine mutation in the Linker for Activation of T cells (LAT) gene. This mutation leads to a number of changes in T cells that result in altered cytokine production including increased IL-4 production, increased proliferation, and decreased apoptosis. Hyper-proliferation of the mutant T cells contributes to lymphadenopathy, splenomegaly, and multi-organ T cell infiltration. miRNAs are short non-coding RNAs that regulate expression of cohorts of genes. This study investigates which miRNAs are expressed in LAT Y136F T cells and compares these to miRNAs expressed in wild type T cells that are undergoing proliferation in two other settings. The first setting is homeostatic proliferation, which was modeled by adoptive transfer of wild type T cells into T cell-deficient mice. The second setting is proliferation in response to infection, which was modeled by infection of wild type mice with the nematode H. polygyrus. By comparing miRNA expression in these three proliferative states (LAT Y136F hyper-proliferation, homeostatic proliferation and proliferation in response to H. polygyrus infection) to expression in wild type naïve CD4+ T cells, we found miRNAs that were highly regulated in all three proliferative states (miR-21 and miR-146a) and some that were more specific to individual settings of proliferation such as those more specific for LAT Y136F lymphoproliferative disease (miR-669f, miR-155 and miR-466a/b). Future experiments that modulate levels of the miRNAs identified in this study may reveal the roles of these miRNAs in T cell proliferation and/or lymphoproliferative disease.

Abstract 3519: Mobilization of follicular lymphoma cells into peripheral blood following BTK inhibition by ibrutinib.

Abstract Introduction: Ibrutinib is an orally administered, highly potent and specific inhibitor of Bruton tyrosine kinase (BTK) in clinical development for the treatment of B cell lymphoproliferative diseases. In the course of the Phase I study of ibrutinib, we found patients with follicular lymphoma (FL) have transient increases of the blood absolute lymphocyte count (ALC) following treatment with ibrutinib, as has been demonstrated with treatment of CLL and MCL patients (Advani et al., 2012a; Wang et al., 2011b., Chang et al., 2011c). We characterized the patterns and phenotypes of blood cells among patients with FL before and following ibrutinib for over 500 days, and further investigated the mechanism of these changes. The baseline ALC of patients with FL treated in the previously reported Phase I study was 1.11 ± 0.12 (x 109 /L, Mean ± SE, n=14). ALC increases of 40-150% (Mean ± SE=59 ± 20%, n=14) occurred following the first two weeks of drug treatments. Patients who were administered drug with 35-day cycles (29 days on, 7-days off) (n=10) exhibited decreases of lymphocytes during the week off treatment, and rapid increases after starting the next cycle of treatment. During this same time, patients experienced reductions in tumor burden as demonstrated by the decrease in Sum of Perpendicular Diameters (SPD). The cyclically increasing lymphocytes were confirmed to be CD19+CD20+CD10+ CD5− light chain restricted, and thus likely to represent circulating, mobilized lymphoma cells. After a single cycle of treatment, these CD19+CD10+ cells had reduced levels of CD38, Ki67 and pErk, consistent with a lower proliferation index. Functionally, ibrutinib inhibited BCR- and CXCL12-mediated adhesion and chemotaxis of FL cell lines in vitro (EC50 = 10-100 nM), and the pseudoemperipoleisis of FL cells in the presence of stromal cells. Conclusion: Transient increases of lymphocytes in the peripheral blood are notable among FL patients treated with ibrutinib. These CD19+CD10+ cells had decreased CD38, Ki67 and pErk expression. The increase in ALC most likely reflects mobilization of FL cells from lymph nodes into the peripheral blood. We have demonstrated that inhibition of BTK activation by ibrutinib results in inhibition of FL cell chemotaxis, adherence and pseudo-emperipoleisis. We propose that Btk activity is essential for the homing of FL cells into secondary lymphoid organstissues, and that its inhibition results in the compartmental shift of FL cells from tissues into the periphery. aAdvani R, J. Clin Oncol. 2012 10.1200/JCO 2012.42.7906. bWang L, American Society of Hematology 2011. cChang BY, in American Society of Hematology 2011. Citation Format: Betty Y. Chang, Padmaja Magadala, Michelle Francesco, Sriram Balasubramanian, Laurence Elias, Joseph J. Buggy. Mobilization of follicular lymphoma cells into peripheral blood following BTK inhibition by ibrutinib. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3519. doi:10.1158/1538-7445.AM2013-3519