Peripheral T-cell Lymphomas

cyTRBC1 evaluation rapidly identifies sCD3-negative peripheral T-cell lymphomas and reveals a novel type of sCD3-negative T-cell clone with uncertain significance

The flow cytometry-based evaluation of TRBC1 expression has been demonstrated as a rapid and specific method for detecting T-cell clones in sCD3-positive TCRαβ+ mature T-cell lymphoma. The aim of the study was to validate the utility of surface (s) TRBC1 and cytoplastic (cy) TRBC1 assessment in detecting clonality of sCD3-negative peripheral T-cell lymphomas (PTCLs), as well as exploring the existence and characteristics of sCD3-negative clonal T-cell populations with uncertain significance (T-CUS). Evaluation of sTRBC1 and cyTRBC1 were assessed on 61 samples from 37 patients with sCD3-negative PTCLs, including 26 angioimmunoblastic T-cell lymphoma (AITL) patients and 11 non-AITL patients. The sCD3-negative T-CUS were screened from 1602 patients without T-cell malignancy and 100 healthy individuals. Additionally, the clonality of cells was further detected through T-cell gene rearrangement analysis. We demonstrated the monotypic expression patterns of cyTRBC1 in all sCD3-negative PTCLs. Utilizing the cyTRBC1 evaluation assay, we identified a novel and rare subtype of sCD3-negative T-CUS for the first time among 13 out of 1602 (0.8%) patients without T-cell malignancy. The clonality of these cells was further confirmed through T-cell gene rearrangement analysis. This subset exhibited characteristics such as sCD3-cyCD3 + CD4 + CD45RO+, closely resembling AITL rather than non-AITL. Further analysis revealed that sCD3-negative T-CUS exhibited a smaller clone size in the lymph node and mass specimens compared to AITL patients. However, the clone size of sCD3-negative T-CUS was significantly lower than that of non-AITL patients in both specimen groups. In conclusion, we validated the diagnostic utility of cyTRBC1 in detecting sCD3-negative T-cell clonality, provided a comprehensive analysis of sCD3-negative T-CUS, and established a framework and provided valuable insights for distinguishing sCD3-negative T-CUS from sCD3-negative PTCLs based on their phenotypic properties and clone size.

Complete hematologic response after belinostat treatment and allogeneic stem cell transplantation for multiple relapsed/refractory angioimmunoblastic T-cell lymphoma: A case report

Key Clinical Message

This case report highlights the potential of belinostat for the treatment of relapsed/refractory peripheral T-cell lymphomas, for which effective therapies are still scarce.

Abstract

Peripheral T-cell lymphomas have an aggressive disease course associated with poor outcomes. We report a young patient with highly pretreated relapsed/refractory nodal follicular helper T-cell lymphoma (angioimmunoblastic-type [nTFHL-AI]), who successfully received an allogeneic stem cell transplantation following belinostat therapy. The complete hematologic response achieved has lasted more than 2 years.

The fusion oncogene VAV1-MYO1F triggers aberrant T-cell receptor signaling in vivo and drives peripheral T-cell lymphoma in mice

VAV1-MYO1F is a recently identified gain-of-function fusion protein of the proto-oncogene Vav guanine nucleotide exchange factor 1 (VAV1) that is recurrently detected in T-cell non-Hodgkin's lymphoma (T-NHL) patients. However, the pathophysiological functions of VAV1-MYO1F in lymphomagenesis are insufficiently defined. Therefore, we generated transgenic mouse models to conditionally express VAV1-MYO1F in T-cells in vivo. We demonstrate that VAV1-MYO1F triggers cell autonomous activation of T-cell signaling with an activation of the ERK, JNK, and AKT pathways. VAV1-MYO1F expression induces a T-cell activation phenotype with high surface expression of CD25, ICOS, CD44, PD-1, and decreased CD62L as well as aberrant T-cell differentiation, proliferation, and neoplastic transformation. Consequently, the VAV1-MYO1F expressing T-cells induce a malignant T lymphoproliferative disease with 100% penetrance in vivo that mimics key aspects of human peripheral T-cell lymphoma. These results demonstrate that the human T-cell oncogene VAV1-MYO1F is sufficient to trigger oncogenic T-cell signaling and neoplastic transformation, and moreover, it provides a new clinically relevant mouse model to explore the pathogenesis of and treatment concepts for human T-cell lymphoma.

PET-CT in Clinical Adult Oncology: I. Hematologic Malignancies

PET-CT is an advanced imaging modality with many oncologic applications, including staging, assessment of response to therapy, restaging and evaluation of suspected recurrence. The goal of this 6-part series of review articles is to provide practical information to providers and imaging professionals regarding the best use of PET-CT for the more common adult malignancies. In the first article of this series, hematologic malignancies are addressed. The classification of these malignancies will be outlined, with the disclaimer that the classification of lymphomas is constantly evolving. Critical applications, potential pitfalls, and nuances of PET-CT imaging in hematologic malignancies and imaging features of the major categories of these tumors are addressed. Issues of clinical importance that must be reported by the imaging professionals are outlined. The focus of this article is on [¹⁸F] fluorodeoxyglucose (FDG), rather that research tracers or those requiring a local cyclotron. This information will serve as a resource for the appropriate role and limitations of PET-CT in the clinical management of patients with hematological malignancy for health care professionals caring for adult patients with hematologic malignancies. It also serves as a practical guide for imaging providers, including radiologists, nuclear medicine physicians and their trainees.

Valproic Acid Inhibits Peripheral T Cell Lymphoma Cells Behaviors via Restraining PI3K/AKT Pathway

Objective

Alproic acid (VPA) is a clinic antiepileptic drug. Antitumor role of VPA has been studied. The aim of this study was to clarify the treatment effect and potential mechanism of VPA on peripheral T cell lymphomas (PTCLs).

Materials and Methods

Hut 78 cells were obtained from the Shanghai Cell Bank, Chinese Academy of Sciences, and randomly divided into six groups: control, VPA (8 mM), empty vector (NC), miR-3196 mimics, miR-3196 inhibitor, and VPA + miR-3196 mimics groups. CCK-8 assay was performed to clarify the regulative role of VPA on cell proliferation. Flow cytometry was applied to determine the apoptotic rate and ROS levels. miR-3196 was tested by RT-qPCR. Western blot was used to test the level of p-PI3K and p-AKT. Biochemical experiments were used to detect changes in the content of ATP, lactate level, and glucose content. Electron microscopy was used to show the structure of mitochondria in Hut 78 cells.

Results

VPA greatly promoted the expression of miR-3196 and inhibited cell proliferation in a dose-dependent manner. Compared with the NC group, the cell apoptosis rate, Bax and cleaved-caspase-3 expression, lactate level, ROS expression, and glucose content in the VPA group were significantly increased (P < 0.05), and cell proliferation, ATP production, and the expression of Bcl-2, p-PI3K and p-AKT was decreased significantly (P < 0.05). The role of mir-3196 mimics is similar to VPA. While, the miR-3196 inhibitor had the opposite effect to VPA and mimics. The combination of VPA and miR-3196 mimics has the most obvious effect.

Conclusion

VPA can inhibit the proliferation of Hut 78 cells and promote cell apoptosis and the structure and dysfunction of mitochondria by regulating the activity of the PI3K/AKT pathway.

Uncommon Variants of Mature T-Cell Lymphomas (MTCLs): Imaging and Histopathologic and Clinical Features with Updates from the Fourth Edition of the World Health Organization (WHO) Classification of Lymphoid Neoplasms

Simple Summary

Familiarity with the updated fourth edition WHO classification of lymphoid malignancies released in 2016, and the new terminology introduced, is crucial for oncologists, pathologists and radiologists. It is mandatory to be aware of rare variants of T-cell lymphomas, specifically mature T-cell lymphomas, including clinicopathologic keys and the most common imaging features and sites of involvement for each subtype. Even though some of these disorders may have perceptible clinical and imaging features, they may overlap with more common disorders, causing delay in diagnosis and treatment. Understanding the appropriate clinical setting and imaging findings will help radiologists to include these disorders in their differential diagnosis. Imaging plays a pivotal role in subclassifying these subtypes of MTCLs, affecting prognosis and treatment implications. Many of these disorders if diagnosed early can be potentially treatable, and early, aggressive intervention may be lifesaving.

Abstract

Understanding the pathogenesis and molecular biology of malignant lymphomas is challenging, given the complex nature and incongruity of these disorders. The classification of lymphoma is continually evolving to account for advances in clinical, pathological, molecular biology and cytogenetic aspects, which impact our understanding of these disorders. The latest fourth edition of the WHO classification of lymphoid malignancies was released in 2016 to account for these changes. Additionally, unlike B-cell lymphomas (BCL), T-cell lymphomas (TCL) are uncommon, and may be sporadically experienced in clinical practice. These disorders are rare, thus early diagnosis is challenging for both physicians and radiologists, owing to the overlap in clinical and imaging features with other, more common disorders. We aim to discuss some rare variants of T-cell lymphomas, including clinicopathologic and imaging features, as well as to give a glimpse of the updates contained within the new 2016 WHO classification.

Burden of illness and treatment patterns among patients with peripheral T-cell lymphoma in the US healthcare setting

OBJECTIVE

Limited real-world information exists on the characteristics or treatment patterns of patients with peripheral T-cell lymphoma (PTCL). We reported demographics, treatments and direct healthcare resource utilization (HRU) in a large cohort of US patients newly diagnosed with PTCL.

METHODS

Patients aged ≥18 years with a PTCL diagnosis between January 2011 and December 2016 were identified from the Inovalon MORE² Registry. Continuous medical/pharmacy enrollment 6-months prior to and ≥1-month after the first PTCL diagnosis was required. The main focus of this study was on newly diagnosed patients receiving cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) versus other chemotherapy.

RESULTS

A total 2971 patients with PTCL and chemotherapy information were included in the study; 1706 (57%) received CHOP and 1265 (43%) other chemotherapy. A majority of patients (51.7%) were female; mean (standard deviation) age at index was 61.0 (±16.0), Charlson score was 4.1 (±2.9), and follow-up time was 24.6 (±16.7) months. During the variable follow-up period, HRU was similar for the CHOP and other chemotherapy cohorts; 58.1% and 59.3% had ≥1 all-cause hospitalizations, respectively. The proportion of patients with ≥1 PTCL-related hospitalizations was higher in the CHOP than in the other chemotherapy cohort (40.3% vs. 9.7%, respectively) and mean length of stay was longer (4.6 vs. 3.7 days per patient per month, respectively).

CONCLUSIONS

This retrospective analysis of patients with PTCL revealed high levels of comorbidity and HRU; novel interventions that improve patient outcomes and reduce the HRU burden of PTCL are needed.

Diagnosis, Risk Stratification, and Treatment of Peripheral T-Cell Lymphomas: Past and Present

Peripheral T-cell lymphomas represent an evolving class of aggressive T-cell malignancies that are generally refractory to conventional treatments and historically carry a poor prognosis. Recent advances in gene expression profiling have begun to unravel the specific molecular mechanisms of tumorigenesis in these disease processes, allowing for discrete classification schemes that help guide discussions regarding prognosis and therapy options. We outline here a review of the histopathology, epidemiology, clinical features, and treatment strategies currently used in the management of these diseases.

Extensive Extranodal Cutaneous Lymphomatous Involvement in a Case of Adult T-Cell Lymphoma - Advantage of 18F Fluorodeoxyglucose Positron-emission Tomography-Computed Tomography over Computed Tomography

Diffuse extranodal cutaneous lymphomatous involvement is a unique presentation in a case of adult T-cell lymphoma. We present the case of a 26-year-old female who presented with erythematous rashes with subsequent evaluation with 18F fluorodeoxyglucose positron-emission tomography-computed tomography showing enlarged inguinal and axillary lymph nodes, and biopsy findings from the inguinal lymph nodes were suggestive of adult T-cell lymphoma.

A new immunotherapy strategy targeted CD30 in peripheral T-cell lymphomas: CAR-modified T-cell therapy based on CD30 mAb

Chimeric antigen receptor T-cell immunotherapy (CAR-T) has shown remarkable efficacy in treating tumors of lymphopoietic origin. Herein, we demonstrate an effective CAR-T cell treatment for recurrent and malignant CD30-positive peripheral T-cell lymphomas (PTCL) has been demonstrated. The extracellular fragment gene sequences of CD30 were obtained from tumor tissues of PTCL patients and cloned into a plasmid vector to express the CD30 antigen. The CD30 targeting single-chain antibody fragment (scFv) was obtained from CD30-positive monoclonal hybridoma cells, which were obtained from CD30 antigen immunized mice. After a second-generation of CAR lentiviral construction, CD30 CAR T cells were produced and used to determine the cytotoxicity of this construct toward Karpas 299 cells. The results of CD30 CAR T-mediated cell lysis show that 9C11-2 CAR T cells could significantly promote the lysis of CD30-positive Karpas 299 cells in both LDH and real-time cell electronic sensing (RTCA) assays. In vivo data show that 9C11-2 CAR T cells effectively suppress the tumor growth in a Karpas 299 cell xenograft NCG mouse model. The CD30 CAR T cells exhibited an efficient cytotoxic effect after being co-cultured with the target cells and they also exhibited a significant tumor-inhibiting ability after being intravenously injected into PTCL xenograft tumors; these observations suggest that the new CD30 CAR-T cell may be a promising therapeutic candidate for cancer therapy.

Health Care Resource Utilization and Costs Among Medicare Beneficiaries Newly Diagnosed With Peripheral T-cell Lymphoma: A Retrospective Claims Analysis

BACKGROUND

There are limited data on the treatment patterns, health care resource utilization (HRU), survival outcomes, and medical costs among Medicare beneficiaries newly diagnosed with peripheral T-cell lymphoma (PTCL).

PATIENTS AND METHODS

This was a retrospective analysis of data from the Medicare Fee-For-Service claims database using the 100% sample of the Medicare research identifiable files. Patients identified for analysis were aged ≥ 65 years and had received a PTCL diagnosis between January 2011 and December 2017. Outcomes included patient characteristics, HRU, direct all-cause and PTCL-specific health care costs, treatment patterns, and overall survival. Patients were followed until disenrollment, death, or end of the study period.

RESULTS

Overall, 2551 patients with PTCL were included, among whom 37% had ≥ 1 emergency department visit and 42% had ≥ 1 hospitalization during the pre-index period. During follow-up (median, 2.0 years), 70% of patients were hospitalized at least once (mean length of stay, 1.34 days); 22% advanced to hospice care. A total of 1593 patients received ≥ 1 identifiable treatment regimen post index, of whom 26% received CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) and 3% CHOEP (CHOP plus etoposide), whereas 71% received other regimens. The median overall survival among patients receiving identifiable therapy was 4.6 years. The mean adjusted per-person-per-month all-cause costs among the overall PTCL cohort during follow-up were $5930; the mean disease-related costs were $2384. Costs were driven primarily by hospitalizations (38%) and outpatient services (28%).

CONCLUSIONS

Medicare beneficiaries newly diagnosed with PTCL have high HRU and cost burden, with no evident standard of care in real-world practice.

Baseline total metabolic tumor volume combined with international peripheral T-cell lymphoma project may improve prognostic stratification for patients with peripheral T-cell lymphoma (PTCL)

Purpose

The aim of this study was to explore the prognostic value of total metabolic tumor volume (TMTV) at baseline ¹⁸F-FDG PET/CT in patients diagnosed with peripheral T-cell lymphoma (PTCL).

Materials and methods

Eighty-four newly diagnosed PTCL patients who underwent baseline ¹⁸F-FDG PET/CT prior to treatment between March 2009 and January 2019 were enrolled in this retrospective study. The FDG-avid lesions in each patient were segmented using semiautomated software to calculate the maximum standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG) values using the boundaries of voxels presenting with the 41% SUVmax threshold method. Progression-free survival (PFS) and overall survival (OS) were used as end points to evaluate patient prognosis. The log-rank test and Cox regression analyses were used to evaluate PFS and OS.

Results

ROC curve analysis indicated an ideal TMTV cut-off value of 228.8 cm³. During the 4–131 months (29.2 ± 28.5 months) follow-up period, high TMTV was significantly associated with worse PFS and OS. TMTV and the international peripheral T-cell lymphoma project score (IPTCLP) were independent predictors of PFS and OS with multivariate analysis. The combination of TMTV and the IPTCLP may provide significantly better risk substratification in PFS and OS of PTCL patients.

Conclusions

Both TMTV and IPTCLP are independent predictors of PTCL patient survival outcomes. Moreover, the combination of TMTV and IPTCLP improved patient risk stratification and may contribute to personalized therapeutic regimens.

[Prognostic significance of NCCN-International Prognostic Index (NCCN-IPI) for patients with peripheral T-cell lymphoma treated with CHOP-based chemotherapy]

目的

明确美国国家综合癌症网络国际预后指数（NCCN-IPI）对外周T细胞淋巴瘤（PTCL）患者化疗后的预后评估价值。

方法

回顾性分析2003年1月至2013年5月接受CHOP或CHOP样方案化疗的162例初治PTCL患者的临床资料，采用国际预后指数（IPI）和NCCN-IPI进行危险分层和预后评估。

结果

①162例患者预期5年总生存（OS）和无进展生存（PFS）率分别为33%和20%，中位OS和PFS时间分别为17.0和9.2个月。②多因素分析提示美国东部肿瘤协作组体能状态评分（ECOG评分）≥2分（PFS：HR＝2.418，95%CI 1.535～3.809，P<0.001；OS：HR＝2.347，95%CI 1.435～3.839，P＝0.001）和存在特定的结外病变部位（PFS：HR＝1.800，95%CI 1.216～2.665，P＝0.003；OS：HR＝1.608，95%CI 1.054～2.454，P＝0.027）是影响患者PFS和OS的独立危险因素；ALK⁺是影响间变性大细胞淋巴瘤患者PFS（HR＝0.424，95%CI 0.184～0.975，P＝0.043）及OS（HR＝0.276，95%CI 0.087～0.877，P＝0.029）的独立预后良好因素。③NCCN-IPI低危组患者的生存率显著高于IPI低危组患者（5年OS率74%对54%，χ²＝5.041，P＝0.025；5年PFS率50%对38%，χ²＝5.295，P＝0.021），差异均有统计学意义。

结论

NCCN-IPI较IPI对低危PTCL患者具有更好的预后判断意义，可作为PTCL患者有效的预后分层工具。

The role of autologous stem cell transplantation in patients with nodal peripheral T-cell lymphomas in first complete remission: Report from COMPLETE, a prospective, multicenter cohort study

BACKGROUND

The role of autologous stem cell transplantation (ASCT) in the first complete remission (CR1) of peripheral T-cell lymphomas (PTCLs) is not well defined. This study analyzed the impact of ASCT on the clinical outcomes of patients with newly diagnosed PTCL in CR1.

METHODS

Patients with newly diagnosed, histologically confirmed, aggressive PTCL were prospectively enrolled into the Comprehensive Oncology Measures for Peripheral T-Cell Lymphoma Treatment (COMPLETE) study, and those in CR1 were included in this analysis.

RESULTS

Two hundred thirteen patients with PTCL achieved CR1, and 119 patients with nodal PTCL, defined as anaplastic lymphoma kinase-negative anaplastic large cell lymphoma, angioimmunoblastic T-cell lymphoma (AITL), or PTCL not otherwise specified, were identified. Eighty-three patients did not undergo ASCT, whereas 36 underwent consolidative ASCT in CR1. At the median follow-up of 2.8 years, the median overall survival was not reached for the entire cohort of patients who underwent ASCT, whereas it was 57.6 months for those not receiving ASCT (P = .06). ASCT was associated with superior survival for patients with advanced-stage disease or intermediate-to-high International Prognostic Index scores. ASCT significantly improved overall and progression-free survival for patients with AITL but not for patients with other PTCL subtypes. In a multivariable analysis, ASCT was independently associated with improved survival (hazard ratio, 0.37; 95% confidence interval, 0.15-0.89).

CONCLUSIONS

This is the first large prospective cohort study directly comparing the survival outcomes of patients with nodal PTCL in CR1 with or without consolidative ASCT. ASCT may provide a benefit in specific clinical scenarios, but the broader applicability of this strategy should be determined in prospective, randomized trials. These results provide a platform for designing future studies of previously untreated PTCL.

Novel CD7-specific nanobody-based immunotoxins potently enhanced apoptosis of CD7-positive malignant cells

Various CD7-targeting immunotoxins have been tested for its potential in treating CD7+ malignant patients but none of those immunotoxins was approved clinically because of lacking enough efficacy and safety. Here we successfully constructed the monovalent and bivalent CD7 nanobody-based immunotoxins PG001 and PG002, both conjugated with a truncated derivative of Pseudomonas exotoxin A respectively. The prokaryotic system expressed immunotoxins not only maintained their binding specificity for CD7-positive cells with a Kd of 16.74 nM and 3.6 nM for PG001 and PG002 respectively, but also efficiently promoted antigen-restricted apoptosis of the CD7-positive leukemia cell lines Jurkat and CEM, and primary T-cell acute lymphoblastic leukemia (T-ALL) and acute myeloid leukemia (AML) cells with an in vitro cytotoxic activity (EC₅₀) in the range of 23-30 pM for PG002. In NOD/SCID mice transplanted with CEM cells, PG001 and PG002 prevented engraftment of the cells and markedly prolonged mouse survival. Owing to the efficient antigen-restricted anti-leukemic activity of PG002, this CD7 nanobody-based immunotoxin exhibited a superior anti-CD7 positive malignancies activity than previously reported immunotoxins, and may represent a promising therapeutic strategy in treating CD7-positive leukemia and lymphoma, which still remain a significant clinical challenge.

Burrowing through the Heterogeneity: Review of Mouse Models of PTCL-NOS

Currently, there are 19 different peripheral T-cell lymphoma (PTCL) entities recognized by the World Health Organization; however, ~70% of PTCL diagnoses fall within one of three subtypes [i.e., peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), anaplastic large-cell lymphoma, and angioimmunoblastic T-cell lymphoma]. PTCL-NOS is a grouping of extra-thymic neoplasms that represent a challenging and heterogeneous subset of non-Hodgkin’s lymphomas. Research into peripheral T-cell lymphomas has been cumbersome as the lack of defining cytogenetic, histological, and molecular features has stymied diagnosis and treatment of these diseases. Similarly, the lacks of genetically manipulated murine models that faithfully recapitulate disease characteristics were absent prior to the turn of the century. Herein, we review the literature concerning existing mouse models for PTLC-NOS, while paying particular attention to the etiology of this heterogeneous disease.

Challenging perspectives on the cellular origins of lymphoma

Both B and T lymphocytes have signature traits that set them apart from other cell types. They actively and repeatedly rearrange their DNA in order to produce a unique and functional antigen receptor, they have potential for massive clonal expansion upon encountering antigen via this receptor or its precursor, and they have the capacity to be extremely long lived as ‘memory’ cells. All three of these traits are fundamental to their ability to function as the adaptive immune response to infectious agents, but concurrently render these cells vulnerable to transformation. Thus, it is classically considered that lymphomas arise at a relatively late stage in a lymphocyte's development during the process of modifying diversity within antigen receptors, and when the cell is capable of responding to stimulus via its receptor. Attempts to understand the aetiology of lymphoma have reinforced this notion, as the most notable advances to date have shown chronic stimulation of the antigen receptor by infectious agents or self-antigens to be key drivers of these diseases. Despite this, there is still uncertainty about the cell of origin in some lymphomas, and increasing evidence that a subset arises in a more immature cell. Specifically, a recent study indicates that T-cell lymphoma, in particular nucleophosmin-anaplastic lymphoma kinase-driven anaplastic large cell lymphoma, may originate in T-cell progenitors in the thymus.

Development of chidamide for peripheral T-cell lymphoma, the first orphan drug approved in China

Peripheral T-cell lymphoma (PTCL) is a set of rare and highly heterogeneous group of mature T- and NK-cell neoplasms associated with poor outcomes and lack of standard and effective therapies. The total number of newly diagnosed cases of PTCL yearly in China is estimated about 50,000. Chidamide (CS055) is a novel and orally active benzamide class of histone deacetylase (HDAC) inhibitor that selectively inhibits activity of HDAC1, 2, 3 and 10, the enzymes that are involved and play an important role in tumor initiation and development in both tumor cells and their surrounding micro-environment. Functioning as a genuine epigenetic modulator, chidamide induces growth arrest and apoptosis in tumor cells and enhances cellular antitumor immunity. Based on the overall results from preclinical and phase I clinical studies, exploratory and pivotal phase II trials of chidamide for relapsed or refractory PTCL were conducted from March 2009 to May 2012, and the results led to CFDA approval of chidamide for the indication in December 2014, being the first approved orphan drug according to the research & development approach of orphan drugs in China, as well as the first orally active drug for PTCL in China and worldwide.

Epstein- Barr Virus: Clinical and Epidemiological Revisits and Genetic Basis of Oncogenesis

Epstein-Barr virus (EBV) is classified as a member in the order herpesvirales, family herpesviridae, subfamily gammaherpesvirinae and the genus lymphocytovirus. The virus is an exclusively human pathogen and thus also termed as human herpesvirus 4 (HHV4). It was the first oncogenic virus recognized and has been incriminated in the causation of tumors of both lymphatic and epithelial nature. It was reported in some previous studies that 95% of the population worldwide are serologically positive to the virus. Clinically, EBV primary infection is almost silent, persisting as a life-long asymptomatic latent infection in B cells although it may be responsible for a transient clinical syndrome called infectious mononucleosis. Following reactivation of the virus from latency due to immunocompromised status, EBV was found to be associated with several tumors. EBV linked to oncogenesis as detected in lymphoid tumors such as Burkitt's lymphoma (BL), Hodgkin's disease (HD), post-transplant lymphoproliferative disorders (PTLD) and T-cell lymphomas (e.g. Peripheral T-cell lymphomas; PTCL and Anaplastic large cell lymphomas; ALCL). It is also linked to epithelial tumors such as nasopharyngeal carcinoma (NPC), gastric carcinomas and oral hairy leukoplakia (OHL). In vitro, EBV many studies have demonstrated its ability to transform B cells into lymphoblastoid cell lines (LCLs). Despite these malignancies showing different clinical and epidemiological patterns when studied, genetic studies have suggested that these EBV- associated transformations were characterized generally by low level of virus gene expression with only the latent virus proteins (LVPs) upregulated in both tumors and LCLs. In this review, we summarize some clinical and epidemiological features of EBV- associated tumors. We also discuss how EBV latent genes may lead to oncogenesis in the different clinical malignancies

Belinostat in Patients With Relapsed or Refractory Peripheral T-Cell Lymphoma: Results of the Pivotal Phase II BELIEF (CLN-19) Study

PURPOSE

Peripheral T-cell lymphomas (PTCLs) represent a diverse group of non-Hodgkin lymphomas with a poor prognosis and no accepted standard of care for patients with relapsed or refractory disease. This study evaluated the efficacy and tolerability of belinostat, a novel histone deacetylase inhibitor, as a single agent in relapsed or refractory PTCL.

PATIENTS AND METHODS

Patients with confirmed PTCL who experienced progression after ≥ one prior therapy received belinostat 1,000 mg/m(2) as daily 30-minute infusions on days 1 to 5 every 21 days. Central assessment of response used International Working Group criteria. Primary end point was overall response rate. Secondary end points included duration of response (DoR) and progression-free and overall survival.

RESULTS

A total of 129 patients were enrolled, with a median of two prior systemic therapies. Overall response rate in the 120 evaluable patients was 25.8% (31 of 120), including 13 complete (10.8%) and 18 partial responses (15%). Median DoR by International Working Group criteria was 13.6 months, with the longest ongoing patient at ≥ 36 months. Median progression-free and overall survival were 1.6 and 7.9 months, respectively. Twelve of the enrolled patients underwent stem-cell transplantation after belinostat monotherapy. The most common grade 3 to 4 adverse events were anemia (10.8%), thrombocytopenia (7%), dyspnea (6.2%), and neutropenia (6.2%).

CONCLUSION

Monotherapy with belinostat produced complete and durable responses with manageable toxicity in patients with relapsed or refractory PTCL across the major subtypes, irrespective of number or type of prior therapies. These results have led to US Food and Drug Administration approval of belinostat for this indication.

Primary nodal peripheral T-cell lymphomas: diagnosis and therapeutic considerations

Nodal peripheral T-cell lymphomas are a rare group of neoplasms derived from post-thymic and activated T lymphocytes. A review of scientific articles listed in PubMed, Lilacs, and the Cochrane Library databases was performed using the term “peripheral T-cell lymphomas”. According to the World Health Organization classification of hematopoietic tissue tumors, this group of neoplasms consists of peripheral T-cell lymphoma not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large cell lymphoma-anaplastic lymphoma kinase positive (ALCL-ALK⁺), and a provisional entity called anaplastic large cell lymphoma-anaplastic lymphoma kinase negative (ALCL-ALK⁻). Because the treatment and prognoses of these neoplasms involve different principles, it is essential to distinguish each one by its clinical, immunophenotypic, genetic, and molecular features. Except for anaplastic large cell lymphoma-anaplastic lymphoma kinase positive, which has no adverse international prognostic index, the prognosis of nodal peripheral T-cell lymphomas is worse than that of aggressive B-cell lymphomas. Chemotherapy based on anthracyclines provides poor outcomes because these neoplasms frequently have multidrug-resistant phenotypes. Based on this, the current tendency is to use intensified cyclophosphamide, doxorubicin, vincristine, prednisolone (CHOP) regimens with the addition of new drugs, and autologous hematopoietic stem cell transplantation. This paper describes the clinical features and diagnostic methods, and proposes a therapeutic algorithm for nodal peripheral T-cell lymphoma patients.

Uncommon non-Hodgkin lymphomas of childhood: pathological diagnosis, clinical features and treatment approaches

We provide a review of the pathological and clinical features for uncommon B-cell and T-cell lymphomas of childhood with a specific focus on advances in treatment approaches and outcomes. There is clearly a need for prospective investigation of both the clinical and biological features of the uncommon non-Hodgkin lymphoma subtypes in childhood. These results should lead to more uniform and more effective treatment approaches.

A New and Validated Clinical Prognostic Model (EPI) for Enteropathy-Associated T-cell Lymphoma

PURPOSE

Enteropathy-associated T-cell lymphoma (EATL) is a rare intestinal non-Hodgkin lymphoma with a poor, though variable prognosis. The International Prognostic Index (IPI) and the prognostic index for peripheral T-cell lymphoma (PIT) have limited predictive value for outcome of EATL. The purpose of this study was to develop and validate a prognostic model for EATL, which can identify high-risk patients who need more aggressive therapy.

EXPERIMENTAL DESIGN

This retrospective multicenter study was based on 92 patients and included 45 patients diagnosed with EATL between 1999 and 2009 from the Netherlands and 47 patients from England and Scotland, diagnosed with EATL between 1994 and 1998. A new EATL prognostic index (EPI) was constructed using the RPART (recursive partitioning and regression trees) procedure. Validation was performed applying the bootstrap method.

RESULTS

Three risk groups were distinguished (P < 0.0001): a high-risk group, characterized by the presence of B-symptoms [median overall survival (OS) of 2 months]; an intermediate-risk group, comprising patients without B-symptoms and an IPI score ≥ 2 (7 months); and a low-risk group, representing patients without B-symptoms and an IPI score of 0 to 1 (34 months). Internal validation showed stability of statistical significance and prognostic discrimination. In contrast with the IPI and PIT, the EPI better classified patients in risk groups according to their clinical outcome.

CONCLUSIONS

Our new, validated, prognostic model EPI accurately predicts survival outcome in EATL and may be used for patient selection for new therapeutic strategies and evaluation of clinical trials.

Anaplastic large cell lymphomas: ALK positive, ALK negative, and primary cutaneous

Anaplastic large cell lymphomas (ALCLs) comprise a group of CD30-positive non-Hodgkin lymphomas that generally are of T-cell origin and share common morphologic and phenotypic characteristics. The World Health Organization recognizes 3 entities: primary cutaneous ALCL (pcALCL), anaplastic lymphoma kinase (ALK)-positive ALCL, and, provisionally, ALK-negative ALCL. Despite overlapping pathologic features, these tumors differ in clinical behavior and genetics. pcALCL presents in the skin and, while it may involve locoregional lymph nodes, rarely disseminates. Outcomes typically are excellent. ALK-positive ALCL and ALK-negative ALCL are systemic diseases. ALK-positive ALCLs consistently have chromosomal rearrangements involving the ALK gene with varied gene partners, and generally have a favorable prognosis. ALK-negative ALCLs lack ALK rearrangements and their genetic and clinical features are more variable. A subset of ALK-negative ALCLs has rearrangements in or near the DUSP22 gene and has a favorable prognosis similar to that of ALK-positive ALCL. DUSP22 rearrangements also are seen in a subset of pcALCLs. In this review, we discuss the clinical, morphologic, phenotypic, genetic, and biological features of ALCLs.

Current management of peripheral T-cell lymphomas

Peripheral T-cell lymphomas (PTCLs) are an uncommon group of lymphoproliferative disorders accounting for approximately 10-15 % of all non-Hodgkin lymphomas (NHL) in Western countries. Although PTCLs are associated with poor prognosis, outcomes vary with disease subtype. The standard of care has been anthracycline-based induction combination chemotherapy, however, with the exception of low-risk ALK-positive anaplastic large cell lymphoma, relapse rates are high. Therefore, consolidation with autologous stem cell transplantation is usually recommended for patients deemed candidates, and with aggressive subtypes. In recent years, a number of novel agents including pralatrexate, histone deacetylase inhibitors, immunotoxins, proteasome inhibitors, aurora kinase inhibitors and the CD30 antibody-drug conjugate brentuximab vedotin, have shown promise in the treatment of PTCLs. Studies are underway to explore the activity of these newer agents used in the frontline setting.

The potential of pralatrexate as a treatment of peripheral T-cell lymphoma

INTRODUCTION

Peripheral T-cell lymphomas (PTCLs) are a group of rare malignancies originating from clonal proliferation of mature, post-thymic T cells that represent 10 - 15% of all non-Hodgkin's lymphomas with poor prognosis and median survival of 1 - 3 years. The standard treatment for PTCL has not yet been identified. Many patients with PTCL are refractory to first-line therapy. The complete response rate ranges from 36 to 66% according to different PTCL subtypes. Furthermore, those who reached a complete or partial response often have a shorter progression-free survival.

AREAS COVERED

This paper discusses the potential of pralatrexate , a methotrexate analogue, as a treatment of PTCL. The authors report on the efficacy and safety data of controlled studies and describe the end points of ongoing trials. Pralatrexate was the first drug to obtain FDA approval for the treatment of patients with relapsed or refractory PTCL. However, the European Medicines Agency has refused marketing authorization.

EXPERT OPINION

None of the treatments commonly used today have given satisfactory results. Pralatrexate seems to be one of the most promising agents in the treatment of patients with PTCL. Future efforts should be focused on better understanding the molecular pathogenesis of PTCL and on specific trials for different PTCL subtypes using rational drug combinations that include pralatrexate.

Treatment of peripheral T-cell lymphoma: are we data driven or driving the data?

Peripheral T-cell lymphomas (PTCL) are a group of uncommon and heterogeneous malignancies arising from a postthymic or mature T-lymphocyte. The treatment of PTCL remains a challenging endeavor. Compared with the more common aggressive B-cell lymphomas, more patients with PTCL will be refractory to initial therapy and those who achieve responses often will have shorter progression-free survival. Despite retrospective data that suggest that anthracycline-based multiagent chemotherapy regimens may not provide a benefit compared with nonanthracycline regimens, nonanthracycline-based regimens, with the notable exception of L-asparaginase regimens for extranodal NK/T-cell lymphoma, have been disappointing so far. Based on phase II evidence and subset analyses available, we believe that the addition of etoposide to standard regimens and consolidation of first remissions with autologous stem cell transplantation (autoSCT) provides the best outcome in patients with PTCL and currently use CHOEP followed by ASCT for eligible patients with the common PTCL subtype: PTCL-NOS, AITL, and ALK negative ALCL. For those with ALK-positive ALCL standard CHOP or CHOEP is appropriate with consideration of ASCT only for those with high-risk disease. Other strategies to incorporate additional agents, such as with dose-adjusted EPOCH or sequential CHOP-ICE regimens are logical options; however, they lack the supporting literature of CHOEP. Whereas the above recommendation is our current off-protocol approach, with the possible exception of low risk ALK positive ALCL, none of these choices is supported by strong enough data to supplant a well-conceived clinical trial as the truly preferred strategy in PTCL. The novel agents, romidepsin, pralatrexate, and brentuximab vedotin, are currently approved in the relapsed/refractory setting. These agents are being studied as additions or substitutions for other agents in up-front multiagent chemotherapy regimens. In the relapsed/refractory setting, both pralatrexate and romidepsin remain well-studied choices with some patients achieving a response with durability. Clinical trials of new agents in PTCL continue to be a valuable option and an important part of routine patient management as progressive disease often is seen. Lastly, we believe patients with relapsed/refractory PTCL should be considered for allogeneic stem cell transplantation if a suitable response is demonstrated and a willing donor is available.

A phase I study of everolimus and CHOP in newly diagnosed peripheral T-cell lymphomas

BACKGROUND

We performed a phase I study to determine the dose and safety of everolimus as a combination chemotherapy in peripheral T-cell lymphoma (PTCL).

METHODS

Four dose levels (2.5 to 10 mg) of everolimus from days 1 to 14 with CHOP (750 mg/m(2) cyclophosphamide, 50 mg/m(2) doxorubicin, and 1.4 mg/m(2) (maximum 2 mg) vincristine on day 1, and 100 mg/day prednisone on days 1 to 5) every 21 days were planned.

RESULTS

Fifteen patients newly diagnosed with stage III/IV PTCL were enrolled. One of 6 patients at dose level 2 (5 mg everolimus) had grade 3 hepatotoxicity and 3 of 6 patients at level 3 (7.5 mg everolimus) had grade 4 hematologic toxicities (two grade 4 thrombocytopenia and one grade 4 neutropenia with fever lasting more than 3 days). The recommended dose of everolimus for combination was 5 mg. There were no differences in steady state trough concentrations of everolimus between cycles 1 and 2 for all three dose levels. All evaluable patients achieved response (8 complete and 6 partial).

CONCLUSIONS

Everolimus (5 mg) can be safely combined with CHOP leading to a feasible and effective regimen for PTCL. The subsequent phase II is now in progress.

Peripheral T-cell lymphomas: a review of current approaches and hopes for the future

Peripheral T-cell lymphomas (PTCL) are a diverse group of lymphoproliferative disorders, which share a common denominator of overall poor prognosis, with few exceptions. In this article, the authors review current standard of care approaches for the treatment of PTCLs, the role of stem-cell/bone marrow transplantation, and current developments in novel targeted therapies.

Strategies for relapsed peripheral T-cell lymphoma: the tail that wags the curve

A 69-year-old woman was referred for further evaluation and management of relapsed angioimmunoblastic T-cell lymphoma. At diagnosis, she received six cycles of dose-adjusted EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) and achieved a complete response (CR). Her first surveillance computed tomography scan 3 months later demonstrated enlarging cervical lymphadenopathy. A lymph node excision confirmed relapsed angioimmunoblastic T-cell lymphoma with atypical lymphocytes expressing CD3, CD4, CD10, PD-1, and EBER, with loss of CD5 (Fig 1). A clonal T-cell receptor beta and gamma rearrangement by polymerase chain reaction was identical to that in her initial diagnostic biopsy. At our initial consultation, options for standard as well as investigational therapies were discussed, and HLA typing was initiated. The patient was enrolled onto an investigational phase II study; however, she developed progressive disease after two cycles. She was then treated with romidepsin 14 mg/m(2) administered intravenously for 3 consecutive weeks with 1 week off. After two cycles, she achieved a partial response, and after four additional cycles, she maintained her response without further improvement. We discussed additional treatment options.

A multicenter phase II trial to determine the safety and efficacy of combination therapy with denileukin diftitox and cyclophosphamide, doxorubicin, vincristine and prednisone in untreated peripheral T-cell lymphoma: the CONCEPT study

This phase II study to determine the safety and efficacy of denileukin diftitox (DD) and cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) enrolled patients with newly diagnosed peripheral T-cell lymphoma (PTCL). Forty-nine received DD 18 μg/kg/day (days 1, 2) with CHOP (day 3) every 21 days for ≤ 6-8 cycles. Intent-to-treat (ITT) and safety populations comprised all patients. In the ITT population, the overall response rate was 65%, median duration of response was 30 months and median progression-free survival was 12 months. Median overall survival was not attained at the end of the study, and the overall survival rate was 63.3%. The two most frequent treatment-related adverse events (AEs) were fatigue and nausea. Most frequent AEs ≥ grade 3 within the hematologic system were lymphopenia (24.5%), neutropenia (20.4%) and leukopenia (18.4%). Three treatment-related deaths occurred. DD plus CHOP was well tolerated, and progression-free and overall survival improved versus historical comparison with CHOP alone. Confirmation in larger trials is warranted.

EuroFlow antibody panels for standardized n-dimensional flow cytometric immunophenotyping of normal, reactive and malignant leukocytes

Most consensus leukemia & lymphoma antibody panels consist of lists of markers based on expert opinions, but they have not been validated. Here we present the validated EuroFlow 8-color antibody panels for immunophenotyping of hematological malignancies. The single-tube screening panels and multi-tube classification panels fit into the EuroFlow diagnostic algorithm with entries defined by clinical and laboratory parameters. The panels were constructed in 2-7 sequential design-evaluation-redesign rounds, using novel Infinicyt software tools for multivariate data analysis. Two groups of markers are combined in each 8-color tube: (i) backbone markers to identify distinct cell populations in a sample, and (ii) markers for characterization of specific cell populations. In multi-tube panels, the backbone markers were optimally placed at the same fluorochrome position in every tube, to provide identical multidimensional localization of the target cell population(s). The characterization markers were positioned according to the diagnostic utility of the combined markers. Each proposed antibody combination was tested against reference databases of normal and malignant cells from healthy subjects and WHO-based disease entities, respectively. The EuroFlow studies resulted in validated and flexible 8-color antibody panels for multidimensional identification and characterization of normal and aberrant cells, optimally suited for immunophenotypic screening and classification of hematological malignancies.

Pediatric T- and NK-cell lymphomas: new biologic insights and treatment strategies

T- and natural killer (NK)-cell lymphomas are challenging childhood neoplasms. These cancers have varying presentations, vast molecular heterogeneity, and several are quite unusual in the West, creating diagnostic challenges. Over 20 distinct T- and NK-cell neoplasms are recognized by the 2008 World Health Organization classification, demonstrating the diversity and potential complexity of these cases. In pediatric populations, selection of optimal therapy poses an additional quandary, as most of these malignancies have not been studied in large randomized clinical trials. Despite their rarity, exciting molecular discoveries are yielding insights into these clinicopathologic entities, improving the accuracy of our diagnoses of these cancers, and expanding our ability to effectively treat them, including the use of new targeted therapies. Here, we summarize this fascinating group of lymphomas, with particular attention to the three most common subtypes: T-lymphoblastic lymphoma, anaplastic large cell lymphoma, and peripheral T-cell lymphoma-not otherwise specified. We highlight recent findings regarding their molecular etiologies, new biologic markers, and cutting-edge therapeutic strategies applied to this intriguing class of neoplasms.

ALK-activating homologous mutations in LTK induce cellular transformation

Leukocyte tyrosine kinase (LTK) is a receptor tyrosine kinase reported to be overexpressed in human leukemia. Though much regarding the function of LTK remains unknown, it shares a high degree of similarity with anaplastic lymphoma kinase (ALK), which is found mutated in human cancer. In order to determine if LTK has transforming potential, we created two LTK mutants, F568L and R669Q, that correspond to two well-characterized activating mutations of ALK (F1174L and R1275Q). LTK-F568L, but not wildtype LTK or LTK-R669Q, transformed hematopoietic cells to cytokine independence. LTK-F568L exhibited a stronger ability to induce loss of contact inhibition and anchorage-independent growth of epithelial cells compared to LTK-R669Q, while wildtype LTK was non-transforming in the same cells. Likewise, LTK-F568L induced greater neurite outgrowth of PC12 cells than R669Q, while wildtype LTK could not. Correlating with transforming activity, LTK-F568L displayed significantly enhanced tyrosine phosphorylation compared to wildtype LTK and LTK-R668Q and induced activation of various signaling proteins including Shc, ERK and the JAK/STAT pathway. Expression of wildtype LTK or LTK-R669Q generally led to weaker activation of signaling proteins than expression of LTK-F568L, or no activation at all. Thus, mutating LTK at residue F568, and to a lesser extent at R669, activates the receptor tyrosine kinase, inducing cell signaling that results in transforming properties. These studies suggest that aberrant activation of LTK may contribute to neoplastic cell growth.

Characterization of a new mouse model for peripheral T cell lymphoma in humans

Peripheral T cell lymphomas (PTCLs) are associated with a poor prognosis due to often advanced disease at the time of diagnosis and due to a lack of efficient therapeutic options. Therefore, appropriate animal models of PTCL are vital to improve clinical management of this disease. Here, we describe a monoclonal CD8⁺ CD4⁻ αβ T cell receptor Vβ2⁺ CD28⁺ T cell lymphoma line, termed T8-28. T8-28 cells were isolated from an un-manipulated adult BALB/c mouse housed under standard pathogen-free conditions. T8-28 cells induced terminal malignancy upon adoptive transfer into syngeneic BALB/c mice. Despite intracellular expression of the cytotoxic T cell differentiation marker granzyme B, T8-28 cells appeared to be defective with respect to cytotoxic activity as read-out in vitro. Among the protocols tested, only addition of interleukin 2 in vitro could partially compensate for the in vivo micro-milieu in promoting growth of the T8-28 lymphoma cells.

TCR-dependent transformation of mature memory phenotype T cells in mice

A fundamental goal in cancer research is the identification of the cell types and signaling pathways capable of initiating and sustaining tumor growth, as this has the potential to reveal therapeutic targets. Stem and progenitor cells have been implicated in the genesis of select lymphoid malignancies. However, the identity of the cells in which mature lymphoid neoplasms are initiated remains unclear. Here, we investigate the origin of peripheral T cell lymphomas using mice in which Snf5, a chromatin remodelling-complex subunit with tumor suppressor activity, could be conditionally inactivated in developing T cells. In this model of mature peripheral T cell lymphomas, the cell of origin was a mature CD44hiCD122loCD8⁺ T cell that resembled a subset of memory cells that has capacity for self-renewal and robust expansion, features shared with stem cells. Further analysis showed that Snf5 loss led to activation of a Myc-driven signaling network and stem cell transcriptional program. Finally, lymphomagenesis and lymphoma proliferation depended upon TCR signaling, establishing what we believe to be a new paradigm for lymphoid malignancy growth. These findings suggest that the self-renewal and robust proliferative capacities of memory T cells are associated with vulnerability to oncogenic transformation. Our findings further suggest that agents that impinge upon TCR signaling may represent an effective therapeutic modality for this class of lethal human cancers.

Lymphopenia is an important prognostic factor in peripheral T-cell lymphoma (NOS) treated with anthracycline-containing chemotherapy

Background

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a heterogeneous group of aggressive T-cell lymphomas with poor treatment outcomes. The aim of this study was to evaluate whether lymphopenia at diagnosis would have an adverse effect on survival in patients with PTCL-NOS treated with anthracycline-containing chemotherapy.

Methods

A total of 118 patients with PTCL-NOS treated with anthracycline-containing chemotherapy from 4 Korean institutions were included.

Results

Thirty-six patients (30.5%) had a low absolute lymphocyte count (ALC, < 1.0 × 10⁹/L) at diagnosis. Patients with lymphopenia had shorter overall survival (OS) and progression-free survival (PFS) rates compared with patients with high ALCs (P = 0.003, P = 0.012, respectively). In multivariate analysis, high-intermediate/high-risk International Prognostic Index (IPI) scores and lymphopenia were both associated with shorter OS and PFS. Treatment-related mortality was 25.0% in the low ALC group and 4.8% in the high ALC group (P = 0.003). In patients considered high-intermediate/high-risk based on IPI scores, lymphopenia was also associated with shorter OS and PFS (P = 0.002, P = 0.001, respectively).

Conclusion

This study suggests that lymphopenia could be an independent prognostic marker to predict unfavorable OS and PFS in patients with PTCL-NOS treated with anthracycline-containing chemotherapy and can be used to further stratify high-risk patients using IPI scores.

Allogeneic transplantation for lymphoma

Historically, high levels of treatment-related mortality restricted the use of standard myeloablative allogeneic stem-cell transplantation to a minority of young and fit patients with lymphoma. Over the last decade, increasing numbers of patients with lymphoma have undergone allogeneic stem-cell transplantation using reduced-intensity protocols that are associated with lower toxicity and reduced transplantation-related mortality. Graft-versus-lymphoma effects contribute to the therapeutic effect in patients with indolent or Hodgkin's lymphoma. However, definitive evidence for efficacy of this strategy is lacking because most patients undergoing transplantation do so after failure of several lines of treatment, leaving no obvious comparator arm for randomized controlled studies. Nevertheless, encouraging results have been reported for selected patients for most lymphoma subtypes, with pretransplantation disease status emerging as the most important predictor of outcome. The major long-term toxicity is chronic graft-versus-host disease that contributes to ill health in a significant minority of survivors. In the future, risk-adapted trials that evaluate reduced-intensity allogeneic transplantation in patients with predicted poor outcomes with immunochemotherapy or autologous transplantation will be important in determining the role of this treatment.

Pathobiology of anaplastic large cell lymphoma

The authors revise the concept of anaplastic large cell lymphoma (ALCL) in the light of the recently updated WHO classification of Tumors of Hematopoietic and Lymphoid Tissues both on biological and clinical grounds. The main histological findings are illustrated with special reference to the cytological spectrum that is indeed characteristic of the tumor. The phenotype is reported in detail: the expression of the ALK protein as well as the chromosomal abnormalities is discussed with their potential pathogenetic implications. The clinical features of ALCL are presented by underlining the difference in terms of response to therapy and survival between the ALK-positive and ALK-negative forms. Finally, the biological rationale for potential innovative targeted therapies is presented.

Activation of T-cell receptor signaling in peripheral T-cell lymphoma cells plays an important role in the development of lymphoma-associated hemophagocytosis

Peripheral T-cell lymphoma (PTCL) is a biologically diverse lymphoid malignancy. The clinical aggressiveness associated with hemophagocytic syndrome (HS) is a characteristic of PTCL, being more distinctive in CD8(+) PTCL. However, the underlying mechanism of PTCL-associated HS has not yet been fully investigated. We newly established a novel IL-2-dependent CD8(+) PTCL lymphoma cell line (T8ML-1) from a patient with CD8(+) PTCL who suffered recurrent HS accompanying disease flare-up. Focusing on the lymphoma cell T-cell receptor (TCR), we examined the lymphoma cell functions responsible for such clinical manifestations. First, T8ML-1.1 in which endogenous TCR-α/β chains were silenced by siRNAs, and T8ML-1.2 in which endogenous TCR-α/β chains were replaced with HLA-A*24:02-restricted and WT1(235-243)-specific TCR-α/β, were established. T8ML-1 exerted phytohemagglutinin (PHA)-dependent cytotoxicity via granular exocytosis. Additionally, soluble factors produced by PHA-stimulated T8ML-1, which included INF-γ and TNF-α, but not by simple-cultured T8ML-1, caused human monocytes to exhibit erythrophagocytosis and thrombophagocytosis in vitro. PHA binding induced phosphorylation of CD3ζ chain. Furthermore, both cytotoxicity and hemophagocytosis were completely inhibited by T8ML-1.1, but eventually restored by T8ML-1.2. These data suggest that exogenous activation of TCR signaling in PTCL cells might play an important role in the formation of PTCL-associated HS.

Rapid Remission in Peripheral T-Cell Lymphoma of the Nasal Type by the Bortezomib plus CHOP Therapy

Peripheral T-cell lymphoma (PTCL) is rare and difficult to treat for its high relapse rate. The authors report a case of PTCL of the skin, regarding which clinical and pathological features, treatment, and prognosis were discussed. A 66-year-old woman was admitted with complaints of enlarging erythematous noduloplaques on the right anterior tibial skin for one year and similar lesions on the left for 6 months. Surgical resection of right leg lesion and biopsy of enlarged inguinal lymph nodes histologically indicated a PTCL of the nasal type. The patient was treated by CHOP plus bortezomib, reached complete remission just after two courses of chemotherapy and then received another two as consolidation. The patient remained in remission for 11 months until local relapse. As for cutaneous lesions, detailed lymph node examination and prompt tissue biopsy are judicious choices prior to any medical management. The chemotherapy consisting of bortezomib and CHOP is safe and efficient in PTCL of the skin.

Diagnosis of Nodal Peripheral T-Cell Lymphomas

Lymph node-based peripheral T-cell lymphomas are rare and exhibit a morphologic spectrum that overlaps with reactive lymphoid hyperplasia, B-cell lymphomas, and Hodgkin lymphoma, presenting a diagnostic challenge. This review focuses on the major categories of lymph node-based peripheral T-cell lymphomas recognized by the 2008 World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues. Diagnostic strategies for approaching T-cell neoplasms using a combined clinical, morphologic, immunophenotypic, and genetic approach are presented. Practical information to aid in distinguishing peripheral T-cell lymphomas from other hematologic malignancies and benign conditions is provided.

Pharmacology of anti-CD3 diphtheria immunotoxin in CD3 positive T-cell lymphoma trials

Anti-CD3 recombinant diphtheria immunotoxin, A-dmDT(390)-bisFv(UCHT1), consists of the catalytic and translocation domains of diphtheria toxin fused to two single chain Fv fragments of an anti-CD3epsilon monoclonal antibody (UCHT1). A-dmDT(390)-bisFv(UCHT1) is capable of killing CD3(+) T-lymphoma cells and normal T cells specifically in the femtomolar concentration range. To study pharmacology of A-dmDT(390)-bisFv(UCHT1) in patients with CD3(+) T-cell lymphoma in a phase I clinical trial, (1) highly sensitive bioassay using Jurkat cells for measuring drug levels, (2) ELISA for measuring anti-DT antibody titer, and (3) 5-color FACS analysis method for measuring changes of subtype T-cell population were developed. In addition to evaluating drug efficacy and pharmacokinetics in patients, it is important to correlate pre-existing anti-DT antibody levels with maximum drug concentration in serum and extent of T-cell depletion because pre-existing anti-DT antibodies due to DPT (Diphtheria, Pertussis, and Tetanus) immunization can neutralize diphtheria immunotoxin. We observed that at the lowest treatment dose (2.5 microg/kg: twice daily for 4 days) A-dmDT(390)-bisFv(UCHT1) depletes greater than 99.0% of normal T cells in all six patients for a short period of time (2-3 days) and that there is no association of C (max) and extent of T-cell depletion with the pre-existing anti-DT antibody titer.

Unusual skin lesions mimicking bruises caused by Pseudomonas septicemia secondary to undiagnosed peripheral T-cell lymphoma in a young woman

We present a case of a 30-year-old woman with learning difficulties who was found dead at home by her mother. Her body was partially naked and covered in a number of unusual skin lesions with a targetoid appearance with red erythematous centers and well-delineated halos of pallor. These lesions were initially thought to be bruises by the police and by a forensic postmortem instigated. Postmortem examination also identified hepatosplenomegaly, severe lymphadenopathy, and focal patchy colonic ulceration. Histologic examination of the skin and bowel ulcers showed the lesions to be areas of infarction caused by Pseudomonas aeruginosa vasculitis. Pseudomonas was also cultured from the swabs of the abdomen, the spleen, and the blood cultures. Histologic findings of the lymph nodes showed complete effacement of the normal architecture by a population of pleomorphic small lymphoid cells. Immunohistochemistry confirmed the predominant cell type to be T-cells. The diagnosis of peripheral T-cell lymphoma was made. The cause of death was given as Pseudomonas septicemia secondary to immunocompromise resulting from the undiagnosed peripheral T-cell lymphoma. The pathogenesis of Pseudomonas and its association with malignancy is discussed along with a brief review of peripheral T-cell lymphomas. This case report demonstrates the characteristic macroscopic appearance of cutaneous Pseudomonas-associated lesions and how they can be misinterpreted as bruises.

Schedule-dependent inhibition of T-cell lymphoma cells by cotreatment with the mTOR inhibitor everolimus and anticancer drugs

OBJECTIVE

Everolimus (RAD001) is a novel mammalian target of rapamycin (mTOR) inhibitor, and anti-proliferative activity in various malignancies has been reported. This study evaluated the anti-tumor effects and schedule-dependent synergism of everolimus in combination with other chemotherapeutic agents in T-cell lymphoma cell lines.

MATERIALS AND METHODS

Human T-cell lymphoma cell lines Hut-78 and Jurkat were treated with increasing doses of everolimus, alone or in combination with doxorubicin, etoposide, vincristine, or bortezomib, using different dosing schedules. Anti-tumor effects were measured by assays for cell proliferation, apoptosis, and cell cycle distribution. Drug interactions were determined by median effect analysis.

RESULTS

Exposure to everolimus alone induced G1 phase cell cycle arrest without significant apoptosis. With certain dosing schedules, everolimus showed synergism with doxorubicin, etoposide, and bortezomib, but antagonism with vincristine. Cytotoxic synergism was observed following cotreatment with doxorubicin and everolimus, bortezomib and everolimus, doxorubicin followed by everolimus, and bortezomib followed by everolimus. By contrast, cell exposure to everolimus followed by doxorubicin or followed by bortezomib resulted in antagonistic effects. Sequential exposure to doxorubicin or bortezomib followed by everolimus effectively prevented potential negative interactions, and resulted in drug synergism. Drug combination synergisms or antagonisms were associated with variable effects on the cell cycle distribution.

CONCLUSIONS

Everolimus effectively inhibited the growth of T-cell lymphoma cells in vitro. Specific schedule-dependent combinations of everolimus with other anti-tumor agents which avoid potential drug antagonism and produce effective synergism may lead to clinically effective treatments for T-cell lymphoma.