Frequency of eosinophilia in adult T-cell leukemia/lymphoma

Understanding the Immunopathology of HTLV-1-Associated Adult T-Cell Leukemia/Lymphoma: A Comprehensive Review

Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL). HTLV-1 carriers have a lifelong asymptomatic balance between infected cells and host antiviral immunity; however, 5-10% of carriers lose this balance and develop ATL. Coinfection with Strongyloides promotes ATL development, suggesting that the immunological status of infected individuals is a determinant of HTLV-1 pathogenicity. As CD4+ T cells play a central role in host immunity, the deregulation of their function and differentiation via HTLV-1 promotes the immune evasion of infected T cells. During ATL development, the accumulation of genetic and epigenetic alterations in key host immunity-related genes further disturbs the immunological balance. Various approaches are available for treating these abnormalities; however, hematopoietic stem cell transplantation is currently the only treatment with the potential to cure ATL. The patient's immune state may contribute to the treatment outcome. Additionally, the activity of the anti-CC chemokine receptor 4 antibody, mogamulizumab, depends on immune function, including antibody-dependent cytotoxicity. In this comprehensive review, we summarize the immunopathogenesis of HTLV-1 infection in ATL and discuss the clinical findings that should be considered when developing treatment strategies for ATL.

CD30 Characterizes Polylobated Lymphocytes and Disease Progression in HTLV-1-Infected Individuals

Purpose: Although expression of CD30 is reported in a subset of adult T-cell leukemia/lymphoma cases, its clinicopathologic significance is poorly understood. We aimed to characterize CD30-positive cells and clarify their tumorigenic role in human T-cell lymphotropic virus type 1 (HTLV-1)-infected cells.Experimental Design: CD30-positive peripheral blood mononuclear cells from individuals with differing HTLV-1 disease status were characterized, and the role of CD30 signaling was examined using HTLV-1-infected cell lines and primary cells.Results: CD30-positive cells were detected in all samples examined, and the marker was coexpressed with both CD25 and CD4. This cell population expanded in accordance with disease progression. CD30-positive cells showed polylobation, with some possessing "flower cell" features, active cycling, and hyperploidy. CD30 stimulation of HTLV-1-infected cell lines induced these features and abnormal cell division, with polylobation found to be dependent on the activation of PI3K. The results thus link the expression of CD30, which serves as a marker for HTLV-1 disease status, to an active proliferating cell fraction featuring polylobation and chromosomal aberrations. In addition, brentuximab vedotin, an anti-CD30 monoclonal antibody conjugated with auristatin E, was found to reduce the CD30-positive cell fraction.Conclusions: Our results indicate that CD30-positive cells act as a reservoir for tumorigenic transformation and clonal expansion during HTLV-1 infection. The CD30-positive fraction may thus be a potential molecular target for those with differing HTLV-1 disease status. Clin Cancer Res; 24(21); 5445-57. ©2018 AACR.

Spinal extradural T-cell lymphoma with paraneoplastic hypereosinophilia in a dog: clinicopathological features, treatment, and outcome

Spinal lymphoma is a rare manifestation of a common canine hematopoietic neoplasia. Description of treatment, outcome, and MRI features are scarce. The latter can be heterogeneous, stressing the importance of lesion excision and analysis. Clinicians should also be aware of hypereosinophilia as accompanying paraneoplastic syndrome and its potential prognostic implications.

The Differential Diagnosis of Eosinophilia in Neoplastic Hematopathology

Eosinophilia in the peripheral blood is classified as primary (clonal) hematologic neoplasms or secondary (nonclonal) disorders, associated with hematologic or nonhematologic disorders. This review focuses on the categories of hematolymphoid neoplasms recognized by the 2008 World Health Organization Classification of Tumours and Haematopoietic and Lymphoid Tissues that are characteristically associated with eosinophilia. We provide a systematic approach to the diagnosis of these neoplastic proliferations via morphologic, immunophenotypic, and molecular-based methodologies, and provide the clinical settings in which these hematolymphoid neoplasms occur. We discuss recommendations that eosinophilia working groups have published addressing some of the limitations of the current classification scheme.

Diagnostic Complexities of Eosinophilia

Context.— The advent of molecular tools capable of subclassifying eosinophilia has changed the diagnostic and clinical approach to what was classically called hypereosinophilic syndrome.

Objectives.— To review the etiologies of eosinophilia and to describe the current diagnostic approach to this abnormality.

Data Sources.— Literature review.

Conclusions.— Eosinophilia is a common, hematologic abnormality with diverse etiologies. The underlying causes can be broadly divided into reactive, clonal, and idiopathic. Classically, many cases of eosinophilia were grouped together into the umbrella category of hypereosinophilic syndrome, a clinical diagnosis of exclusion. In recent years, an improved mechanistic understanding of many eosinophilias has revolutionized the way these disorders are understood, diagnosed, and treated. As a result, specific diagnoses can now be assigned in many cases that were previously defined as hypereosinophilic syndrome. Most notably, chromosomal rearrangements, such as FIP1L1-PDGFRA fusions caused by internal deletions in chromosome 4, are now known to be associated with many chronic eosinophilic leukemias. When present, these specific molecular abnormalities predict response to directed therapies. Although an improved molecular understanding is revolutionizing the treatment of patients with rare causes of eosinophilia, it has also complicated the approach to evaluating and treating eosinophilia. Here, we review causes of eosinophilia and present a framework by which the practicing pathologist may approach this diagnostic dilemma. Finally, we consider recent cases as clinical examples of eosinophilia from a single institution, demonstrating the diversity of etiologies that must be considered.

Lymphoproliferative disorders associated with hypereosinophilia

Hypereosinophilia, defined as peripheral blood eosinophil counts > 1,500/μL, may complicate the course of various lymphoproliferative disorders. Among these, Hodgkin lymphoma (HL) and certain peripheral T-cell lymphomas (PTCLs) derived from CD4 cells, including Sezary syndrome (SS), adult T-cell leukemia/lymphoma (ATLL), and angioimmunoblastic T-cell lymphoma (AITL), are most commonly associated with increased reactive eosinophilopoiesis. Rarely, marked hypereosinophilia (HE) may occur in the setting of acute B-cell lymphoblastic leukemia, with a substantial impact on disease course. The mechanisms leading to blood and tissue eosinophilia in the setting of lymphoproliferative disorders, as well as the clinical complications and prognostic implications of hypereosinophilia, are discussed in this review.

Eosinophilia and eosinophilic infiltration into splenic B-cell high-grade lymphoma in a dog

A 13-year-old mixed-breed dog showing ascites, anorexia and anemia was found to have leukocytosis with marked eosinophilia, splenomegaly and hepatomegaly. The dog died 4 days after initial presentation and was diagnosed with splenic high-grade B-cell lymphoma at necropsy. Remarkable infiltrations of eosinophils were observed in spleen and liver tissues. The eosinophilia and infiltration of eosinophils into the lesions could have been associated with B-cell lymphoma because causes other than lymphoma were excluded. This is the first report of eosinophilia and eosinophilic infiltrations into neoplastic lesions in a dog with high-grade B-cell lymphoma.

Hypereosinophilic syndrome: current approach to diagnosis and treatment

Hypereosinophilic syndrome is a heterogeneous group of rare disorders characterized by marked blood or tissue eosinophilia resulting in a wide variety of clinical manifestations. Although the existence of clinical subtypes (or variants) of HES has been appreciated for some time, the recent characterization of some of these variants at the molecular and immunologic levels has demonstrated dramatic differences in disease pathogenesis, response to treatment, and prognosis depending on the etiology of the eosinophilia. This, together with the availability of novel targeted therapies, including tyrosine kinase inhibitors and monoclonal antibodies, has fundamentally altered the approach to the diagnosis and treatment of HES.

Follicular lymphoma with marked infiltration of eosinophils

Eosinophilia and tissue infiltration by eosinophils are frequent findings in Hodgkin lymphoma, but they are extremely rare in B-cell lymphoma. Reported herein is a case of follicular lymphoma with extensive lymph node infiltration by eosinophils. The patient was a 71-year-old woman who had a mass in the vicinity of the pancreas found on routine ultrasonography. Subsequent CT indicated several enlarged abdominal lymph nodes, although superficial lymph nodes were not palpable. Two swollen mesenteric lymph nodes were excised to determine the cause of the lymphadenopathy. Histology indicated extensive infiltration of numerous eosinophils to the interfollicular area, especially in the dilated sinuses. The lymphoid follicles were relatively small, had inconspicuous germinal centers, and were scattered between dilated sinuses. Based on the histology, immunohistochemistry, and chromosomal abnormality, a diagnosis of follicular lymphoma was made. Expression of interleukin-3 (IL-3), IL-5, eotaxin, eotaxin-2, and eotaxin-3 was investigated on reverse transcription-polymerase chain reaction of the lymph node tissue, but none of the mRNA expression levels were elevated. This was a unique case of follicular lymphoma with extensive eosinophil infiltration, and to the best of the authors' knowledge this is the first such case ever reported.

Eosinophilia is associated with a higher mortality rate among patients with autoimmune lymphoproliferative syndrome

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder associated with heritable defects in lymphocyte apoptosis that result in chronic nonmalignant lymphadenopathy, splenomegaly, and autoimmunity. To examine the prevalence, mechanisms, and potential implications of eosinophilia in ALPS, we reviewed data retrospectively from 187 consecutive ALPS patients and their family members studied at the National Institutes of Health. ALPS patients with eosinophilia were compared with ALPS patients without eosinophilia with respect to their clinical and immunologic phenotype. Potential mechanisms for the eosinophilia, including abnormal Fas-mediated eosinophil apoptosis, increased production of eosinophilopoietic cytokines, and presence of anti-eosinophilic autoantibodies were also explored in a small number of patients from whom samples were available. Analysis of data from 68 ALPS patients and 119 of their relatives identified a distinct subgroup of patients with prominent and persisting eosinophilia that proved to be associated with increased numbers of peripheral blood leukocytes (PBL) of multiple lineages and a trend towards increased serum IgE levels. Eosinophilic ALPS patients also had a significantly higher risk of death due to infectious complications. Although the specific etiology of the eosinophilia in these patients remains uncertain, it does not appear to be associated with an altered serum cytokine profile, increased survival responsiveness of eosinophils to IL-5, defective Fas-mediated eosinophil apoptosis, or anti-eosinophil antibodies. Eosinophilia defines a distinct subgroup of ALPS patients with increased serum IgE levels, increased numbers of PBL of multiple lineages, and higher mortality from infectious complications.

Impact of visceral involvements and blood cell count abnormalities on survival in adult T-cell leukemia/lymphoma (ATLL)

Multiple visceral involvements and various blood cell count abnormalities are frequently manifested in adult T-cell leukemia/lymphoma (ATLL) at diagnosis. We evaluated the effects of four visceral involvement (bone marrow (BM), skin, liver, spleen) and six blood cell count abnormalities (anemia, neutrophilia, thrombocytopenia, monocytosis, eosinophilia, basophilia) on the overall survival of 168 ATLL patients. In the aggressive type, BM involvement, skin involvement and monocytosis were significantly poor prognostic factors. Furthermore, concomitant involvement of BM and additional visceral organs worsened the prognosis. These data support that multiple organ involvements represent a poor prognostic factor for ATLL and provide clinical significance for BM examinations.

Clinical significance of a blood eosinophilia in adult T-cell leukemia/lymphoma: a blood eosinophilia is a significant unfavorable prognostic factor

We investigated the clinical significance of a blood eosinophilia in a cohort of 158 consecutive patients with adult T-cell leukemia/lymphoma (ATLL), and multivariate analysis revealed that a blood eosinophilia was an independent and a significant unfavorable prognostic factor. Interestingly, a blood eosinophilia was independent of serum LDH level, which might reflect the tumor burden. The present study shows that measurement of the blood eosinophil count is useful for predicting the prognosis and for determining a suitable treatment strategy for ATLL patients.

T-cell lymphoblastic leukemia/lymphoma syndrome with eosinophilia and acute myeloid leukemia

This case represents an example of an unusual T-cell lymphoblastic leukemia/lymphoma syndrome associated with eosinophilia and myeloid malignancy in a young boy. This case is one of only five reported "leukemic" variants of the disease and demonstrates the importance of considering this poor prognostic diagnosis in pediatric acute lymphoblastic leukemia. This case also illustrates the importance of an interactive multidisciplinary approach to the laboratory evaluation of a leukemia patient.

IL-2- and STAT5-regulated cytokine gene expression in cells expressing the Tax protein of HTLV-1

Interleukin-2 (IL-2) mediates cell cycle progression and antiapoptosis in human T cells via several signal transduction pathways. The Tax protein of the human T-cell leukemia virus type I (HTLV-1) deregulates cell growth and alters the role of IL-2 in infected cells. However, Tax-immortalized cells stay dependent on IL-2, suggesting that events besides HTLV-1 gene expression are required for leukemia to develop. Here, IL-2-dependent and -independent events were analysed in a human T cell line immortalized by Tax. These studies show that, of the signaling pathways evaluated, only STAT5 remains dependent. Microarray analyses revealed several genes, including il-5, il-9 and il-13, are uniquely upregulated by IL-2 in the presence of Tax. Bioinformatics and supporting molecular biology show that some of these genes are STAT5 targets, explaining their IL-2 upregulation. These results suggest that IL-2 and viral proteins work together to induce gene expression, promoting the hypothesis that deregulation via the constitutive activation of STAT5 may lead to the IL-2-independent phenotype of HTLV-1-transformed cells.

Eosinophilic fasciitis associated with autoimmune thyroiditis

Eosinophilic fasciitis (EF) is scleroderma-like disease without Raynaud's phenomenon or visceral involvement. It is characterized by painful swelling of the extremities, accompanied by rapid weight gain, fever and myalgia. The acute state of disease is associated with significant peripheral blood eosinophilia, an elevated erythrocyte sedimentation rate and hypergammaglobulinemia. EF is also frequently associated with hematological abnormalities, including malignant lymphoproliferative diseases, but rarely associated with autoimmune thyroiditis. In the present study we report a case of eosinophilic fasciitis associated with autoimmune thyroiditis.

In situ eosinophil activation in 26 primary cutaneous T-cell lymphomas with blood eosinophilia

Blood and tissue eosinophils can be associated with Hodgkin and non-Hodgkin lymphomas in that they have prognostic value. Tissue eosinophils in T-cell lymphoma patients with blood eosinophilia have not been systematically assessed. The objective of this research was to study the presence, density, and activation of tissue eosinophils in patients with primary cutaneous T-cell lymphomas (CTCLs) with blood eosinophilia and a possible relationship between features of the disease and prognosis. With skin biopsy specimens from 26 CTCL patients with blood eosinophilia, tissue eosinophils were studied with electron microscopy, extracellular eosinophil peroxidase deposits, and interleukin-5 expression. Tissue eosinophils, found in 22 of 26 cases, were constantly activated. Both density and activation of tissue eosinophils were significantly related to disease progression. The state of activation of tissue eosinophils in CTCL might reflect inflammatory flare-ups associated with aggressive lymphomas. Further studies are needed to confirm the value of eosinophil density as a simple and reliable marker of CTCL progression.

Peripheral T-cell lymphoma with eosinophilia presenting as monoarthritis: a case study

Direct involvement of the joints is unusual in patients with non-Hodgkin's lymphoma (NHL). This may pose a diagnostic problem for pathologists, especially since synovial localization can disclose NHL. In the following case of T-cell NHL with eosinophilia, we point out the essential importance of clonality analysis on frozen tissue to distinguish between synovial NHL and specific inflammatory damage.

Roles of CCAAT/enhancer-binding protein in transcriptional regulation of the human IL-5 gene

Interleukin-5 (IL-5) plays a critical role in the pathogenesis of eosinophil-associated allergic disorders, such as asthma. IL-5 may also play a major role in the development of eosinophilia-associated lymphoproliferative disorders caused by human T lymphotropic virus type I (HTLV-I). In this study, we have investigated the control mechanisms for IL-5 production and found that ectopic expression of NF-IL6 (C/EBPbeta) increases endogenous IL-5 mRNA expression. The IL-5 promoter contains four C/EBP consensus sequences. We show here that one of the C/EBP site at - 235 promoter region binds to NF-IL6 protein with high affinity and interacts with NF-IL6 and NF-IL6beta (C/EBPdelta) in Jurkat T cells. Mutations within the C/EBP sequence reduced the promoter activity in response to T cell activation by more than 50 %. In addition, we show that in vivo inducible expression of Tax protein in Jurkat T cells stably transfected with Tax further increased ionomycin plus phorbol ester stimulated IL-5 promoter activity. The effect of Tax on IL-5 promoter activity was abolished when the C/EBP site was mutated. Thus, the C/EBP site may be also involved in HTLV-I Tax-mediated up-regulation of IL-5 gene expression. Our data suggest that C/EBP proteins may regulate IL-5 gene expression in response to different stimulation signals.

Human T-lymphotropic virus type 1 infection

Human T-cell lymphotropic virus type-1 (HTLV-1) is aetiologically associated with adult T-cell leukaemia/lymphoma (ATL). HTLV-1 infection can also lead to various non-malignant diseases, for example, HTLV-1 associated myelopathy/tropical spastic paraparesis and HTLV-1 uveitis. HTLV-1 is endemic in southern Japan and the Caribbean. HTLV-1 infection is mainly transmitted by either breast-feeding, sexual intercourse or blood transfusions. Primary prevention of HTLV-1 in endemic areas by screening of blood and by refraining from breast-feeding have been successful. The incidence of ATL is rather low among HTLV-1 carriers (<5%). The precise mechanism of development of ATL remains unknown. It is a multiple-step process which does not require viral expression in the later stages of leukaemogenesis. Many samples have mutations of the tumour suppressor genes, p53 and/or p16(INK4A). Four subtypes of ATL have been identified, each having distinctive clinical features. Monoclonal integration of HTLV-1 proviral DNA into tumour cells is found in each of the subtypes. At present, no effective therapy for ATL exists.

Pathological roles of interleukin-15 in adult T-cell leukemia

Interleukin-15 (IL-15) is a 14-kDa glycoprotein belonging to the same four helix bundle-cytokine family as IL-2. Although the biological activity of IL-15 in vitro has been studied extensively, its physiological role is still obscure. The receptors for IL-15 and IL-2 consist of three subunits, an unique alpha chain and shared beta and gamma chains. Since beta and gamma chains transduce the signals from the receptors, both cytokines share similar biologic functions, although IL-15 and IL-2 do not have sequence homology. The alpha chains function to increase binding affinity for each cytokines. Adult T-cell leukemia (ATL) cells constitutively express the IL-2 receptor (IL-2R) alpha and expression is believed to be essential in the early stages of disease development. We have recently shown that ATL cells also express the complete form of IL-15R including the alpha chain, and that ATL cells proliferate in response to exogenous IL-15. Since the mRNA of IL-15 is ubiquitous and is detected in many tissues and cells, it is possible that IL-15R stimulation is involved in the development and progression of ATL. Here, we review recent studies on IL-15 and IL-15R and their association with ATL and other lymphoproliferative disorders.

Regulation of the human interleukin-5 promoter by Ets transcription factors. Ets1 and Ets2, but not Elf-1, cooperate with GATA3 and HTLV-I Tax1

Interleukin-5 (IL-5), expressed primarily by type-2 T helper (Th2) cells, plays an important role in the development of allergic diseases, such as allergic asthma. Studying the regulation of IL-5 gene expression by Ets transcription factors, we found that Ets1 and Ets2, but not Elf-1, were able to activate the human IL-5 promoter in Jurkat T-cells. This required the presence of either phorbol 12-myristate acetate (PMA) plus ionomycin or PMA plus the viral protein HTLV-I Tax1. By mutation studies, it could be shown that Ets1 and Ets2 exerted their effects on the IL-5 promoter through a GGAA motif within the Cle0 element. In myeloid Kasumi cells, Ets1 and Ets2 failed to stimulate IL-5 promoter activity, unless the T-cell specific transcription factor GATA3 was added. These results show, for the first time, that Ets1 and Ets2 are able to cooperate with GATA3. Both ionomycin and Tax1 increased the combined effect of GATA3 with Ets1 and Ets2 in the presence of PMA. The data further demonstrate that, in addition to Ets1, Ets2 is also able to functionally cooperate with Tax1. The synergism of GATA3 with either Ets1 or Ets2 may play an important role in calcium- or Tax1-dependent regulation of IL-5 expression in Th2 cells or in HTLV-I transformed adult T-cell leukemia cells, respectively.

Primary gastric T-cell lymphomas: report of two cases and a review of the literature

To understand more fully the clinicopathological features of primary gastric T-cell lymphomas (PGTL), we report two cases of PGTL and review the literature. The present cases were not associated with human T-cell leukemia virus type 1 (HTLV-1) and were at clinical stage IIE. In both cases, T-cell origin of the lymphoma cells was diagnosed immunohistochemically. The clinical courses of these two cases were different: one followed a very aggressive clinical course and the patient died 6 months after the diagnosis, whereas the other patient survived more than 2 years without adjuvant chemotherapy. Clinicopathological features of 23 patients with PGTL are summarized with regard to their differences from primary small intestinal T-cell lymphomas (PSITL) and by association with HTLV-1. The median age at onset of PGTL was 58 years. The gender ratio was male-dominant (M:F = 2.3:1). About two-thirds (10 of 17) of PGTL cases had evidence of HTLV-1 infection. The most common presenting symptom for PGTL was upper abdominal discomfort and/or pain (76%), whereas that in PSITL was weight loss (61%) and diarrhea (42%). Typical lesions for PGTL were large ulcerations at the corpus to antrum. Neoplastic cells had no typical morphological characteristics for PGTL including HTLV-1-associated cases. CD3+4+8- was the most frequently observed surface phenotype of PGTL cells. Laboratory findings at diagnosis were not informative. Most patients were treated by gastrectomy with or without chemotherapy. PGTL, excluding that with HTLV-1, showed better prognosis than PSITL, although PGTL with HTLV-1 had a poorer prognosis.

Eosinophilia associated with adult T-cell leukemia: role of interleukin 5 and granulocyte-macrophage colony-stimulating factor

To clarify the mechanism of eosinophilia in adult T-cell leukemia (ATL), we studied three ATL patients having marked eosinophilia. Eosinophil-predominant colony-stimulating activity was detected in the serum of one patient and in the conditioned media (CM) from cultured ATL cells from two patients. Soluble interleukin 5 (IL-5), but no interleukin 3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF), was detected in sera from all patients. On the other hand, GM-CSF was produced in vitro by ATL cells from all cases, whereas detectable IL-3 and IL-5 was produced by cells from only one, suggesting that in the other two cases, the serum IL-5 was produced by the normal reacting lymphocytes. The fact that no patient showed marked neutrophilia supports the possibility that IL-5 may have a leading role in the development of eosinophilia, with GM-CSF produced by ATL cells playing a complementary role.

Anaplastic large cell malignant lymphoma with extensive eosinophilic or neutrophilic infiltration

AIMS

We describe the clinicopathological features of eight cases of Ki-1 positive anaplastic large cell malignant lymphoma (Ki-1 ALCL) in which there was extensive infiltration by eosinophils and/or neutrophils in the absence of necrosis.

METHODS AND RESULTS

The patients comprised four males and four females with an age range of 24-74 years. Five cases had originally been diagnosed as Hodgkin's disease and one as true histiocytic lymphoma. In all cases, there was massive infiltration by eosinophils and/or neutrophils sometimes to such an extent that malignant cells were obscured. Immunohistochemical staining was performed using the monoclonal antibodies CD30, CD15, CD45, CD20, CD3, CD45RO, epithelial membrane antigen (EMA), CAM5.2, vimentin and CD68. In all cases, tumour cells were strongly positive for CD30 but negative for CD15. One case was positive for CD45 but none expressed B or T-cell markers. Five cases were positive for vimentin and two for EMA. Three of seven patients in whom adequate clinical details were available had stage III or IV disease at presentation and four exhibited B symptoms. Four patients had a peripheral neutrophilia and one a peripheral eosinophilia.

CONCLUSIONS

The study shows that an eosinophil and/or neutrophil-rich variant of Ki-1 ALCD exists, expanding the morphological spectrum of this tumour.

Eosinophilia associated with clonal T-cell proliferation

Eosinophilia associated with the expansion of cloned T-cells is reviewed in relation to cytokine production. It has been proved that eosinophilopoiesis is caused by eosinophil-stimulating cytokines, including interleukin-5 (IL-5), granulocyte-macrophage colony-stimulating factor and interleukin-3, which are secreted from T-cells. Recently, we and other groups have reported several cases of eosinophilia including hypereosinophilic syndrome (HES) accompanied with proliferation of abnormal T-cells with an unusual phenotype CD3- CD4+ or CD3+ CD4- CD8- in the peripheral blood. The T-cells clonally proliferate, as confirmed by clonal rearrangements of the T-cell receptor (TCR) gene, and produce eosinophil-stimulating cytokines, especially IL-5, with or without stimulation in vitro. Although HES is defined by the combination of unexplained prolonged eosinophilia and evidence of organ involvement, these observations suggest that increased production of eosinophil-stimulating cytokines from the abnormal T-cells with phenotype CD3- CD4+ or CD3+ CD4- CD8- may cause eosinophilia, some of which have been diagnosed as HES.

Triple synergism of human T-lymphotropic virus type 1-encoded tax, GATA-binding protein, and AP-1 is required for constitutive expression of the interleukin-5 gene in adult T-cell leukemia cells

Accumulated evidence demonstrates that adult T-cell leukemia (ATL) is frequently associated with eosinophilia, and human T-lymphotropic virus type 1 (HTLV-1)-infected cells frequently express interleukin-5 (IL-5). However, the molecular mechanism of constitutive IL-5 expression in HTLV-1-infected cells remains unclear. To clarify the mechanism of aberrant IL-5 expression in HTLV-1-infected cells, we investigated the response of the human IL-5 promoter to the HTLV-1-encoded protein Tax. Cotransfection experiments using Jurkat cells revealed that Tax is incapable of activating the IL-5 promoter by itself but that it synergistically transactivates the promoter with GATA-binding protein (GATA-4) and 12-O-tetradecanoylphorbol-13-acetate (TPA) stimulation. By introducing a series of mutations within the IL-5 promoter, we found that conserved lymphokine element 0 (CLE0) is responsible for mediating the signal induced by Tax-TPA. A deletion construct of the promoter indicated that the -75 GATA element and CLE0 are sufficient to mediate synergistic activation of the IL-5 promoter. Electrophoretic mobility shift assays using Jurkat cell nuclear extracts demonstrated that TPA induces a transcription factor to bind CLE0, and an experiment using JPX-9 cell nuclear extracts showed that Tax enhances this binding activity. An antibody supershift experiment revealed that this band consists of c-Jun and JunD. However, among the Jun family members, only c-Jun is able to cooperate with Tax and GATA-4 to activate the IL-5 promoter. We have determined the minimum factors required for IL-5 gene activation by reconstituting the IL-5 promoter activity in F9 cells. This is the first report to demonstrate the functional involvement of Tax protein in IL-5 gene regulation and to suggest the functional triple synergism among Tax, GATA-4, and AP-1, which disrupts regulated control of the gene and leads to constitutive expression of the IL-5 gene.

Primary gastric T-cell lymphoma with and without human T-lymphotropic virus type 1

BACKGROUND

Gastric T-cell lymphomas are rare, and their incidence and viral status have not yet been fully clarified.

METHODS

Sixty-seven cases of surgically resected gastric lymphomas from city hospitals in Tokyo were evaluated. The surface phenotype was determined by immunohistochemistry, gene rearrangement by Southern blot hybridization, association with Epstein-Barr virus (EBV) by EBV-encoded small RNAs in situ hybridization, and the presence of human T-cell lymphotropic virus type 1 (HTLV-1) by serology, Southern blot hybridization, and polymerase chain reaction analysis.

RESULTS

Five of the 67 cases were T-cell lymphoma (7%): 3 cases were HTLV-1 negative (-) and 2 were HTLV-1 positive (+). Systemic eosinophilia was observed in the three HTLV-1(-) gastric lymphomas. Neoplastic cells were morphologically similar in both groups, but a granulomatous reaction with marked eosinophilia was observed only in the two cases of HTLV-1(-) lymphoma. They also had characteristics of natural killer (NK) cell-like T-cell lymphoma, expressing NK markers and TCRgamma gene rearrangement. Positivity with HML-1 (specific for intestinal epithelial T-cells lymphoma was observed in one HTLV-1(+) lymphoma. The EBV gene was detected in only one case of B-cell lymphoma but not in any case of T-cell lymphoma.

CONCLUSIONS

Gastric T-cell lymphoma occurs in 7% of gastric lymphomas in Japan and is comprised of HTLV-1-related lymphomas and lymphomas unrelated to HTLV-1, including NK cell-like lymphomas with eosinophilia.

Plasma M-CSF as an indicator of response to chemotherapy in adult T cell leukemia patients

The plasma concentration of macrophage colony-stimulating factor (M-CSF) was measured in 10 patients with acute type adult T cell leukemia (ATL) during the clinical course before and after chemotherapy. M-CSF concentration decreased significantly when the patients achieved complete remission (CR) or partial remission (PR) (t-test: p = 0.0001). Five of the patients showed disease progression after several months of PR, and plasma M-CSF increased at that time (t-test: p = 0.0456). Thus, plasma M-CSF concentration appeared to accurately reflect the disease activity in ATL. In support of these results, all three ATL cell lines established from these patients secreted M-CSF in vitro after stimulation with phorbol myristate acetate (PMA) or concanavalin A (Con A). Plasma M-CSF concentration, however, increased transiently when the patients were febrile (t-test: p = 0.0001), even though their ATL condition was unchanged. Taken together, these results indicate that there are two sources of increased plasma M-CSF concentration in ATL; ATL cells themselves and normal parenchymal cells that cause this increase as the result of elevated body temperature due to inflammation.

Features of the cytokines secreted by adult T cell leukemia (ATL) cells

Adult T cell leukemia (ATL) cells show a mature helper-inducer T cell phenotype and are thought to secrete many kinds of cytokines in vivo, complicating the clinical features in these patients. In an attempt to specify the cytokines produced by ATL cells, we measured the cytokine concentration in the culture supernatants of three ATL cell lines, all of which were confirmed to be true peripheral blood ATL cell in origin. All these cell lines showed the same cytokine production profile, secreting IL1-alpha, IL1-beta, LD78(MIP-l alpha), TNF-alpha, IFN-gamma, and GM-CSF, but not secreting IL-1 alpha, IL-1 beta, IL-1 receptor antagonist (IL-1 Ra), IL-4, IFN-alpha, and G-CSF irrespective of the stimulatory agents used. Such limited cytokine production may indicate the specific origin of ATL cells within the helper-inducer T cell subtypes. Moreover, these results explain some of the unusual clinical features of ATL patients.

Of the GATA-binding proteins, only GATA-4 selectively regulates the human interleukin-5 gene promoter in interleukin-5-producing cells which express multiple GATA-binding proteins

Interleukin-5 (IL-5) is produced by T lymphocytes and known to support B-cell growth and eosinophilic differentiation of the progenitor cells. Using ATL-16T cells which express IL-5 mRNA, we have identified a region within the human IL-5 gene promoter that regulates IL-5 gene transcription. This cis-acting sequence contains the core binding motif, (A/T)GATA(A/G), for GATA-binding family proteins and thus suggests the involvement of this family members. In this report, we describe the cloning of human GATA-4 (hGATA-4) and show that hGATA-4 selectively interacts with the -70 GATA site within the IL-5 proximal promoter region. By promoter deletion and mutation analyses, we established this region as a positive regulatory element. Cotransfection experiments revealed that both hGATA-4 and phorbol-12-myristate-13-acetate (PMA)-A23187 stimulation are necessary for IL-5 promoter activation. The requirement for another regulatory element called CLE0, which lies downstream of the -70 GATA site, was also demonstrated. ATL-16T cells express mRNAs of three GATA-binding proteins, hGATA-2, hGATA-3, and hGATA-4, and each of them has a potential to bind to the consensus (A/T)GATA(G/A) motif. However, using ATL-16T nuclear extract, we demonstrated that GATA-4 is the only GATA-binding protein that forms a specific DNA-protein complex with the -70 GATA site. An electrophoretic mobility shift assay with extracts of COS cells expressing GATA-binding proteins showed that GATA-4 has the highest binding affinity for the -70 GATA site among the three GATA-binding proteins. When the transactivation abilities were compared among the three, GATA-4 showed the highest activity. These results demonstrate the selective role of GATA-4 in the transcriptional regulation of the IL-5 gene in a circumstance where multiple members of the GATA-binding proteins are expressed.

A case of pleomorphic T-cell lymphoma with a high content of reactive histiocytes presented with hypereosinophilia

A case of peripheral T-cell lymphoma classified, according to the updated Kiel classification, as a large pleomorphic T-cell lymphoma with a high content of reactive histiocytes and blood hypereosinophilia is reported. Light microscopic examination revealed a diffuse effacement of the lymph node structure by large pleomorphic lymphoma cells mixed with eosinophils and many histiocytes, some of them presenting discrete features of hemophagocytosis. The neoplastic cells were CD3, CD5, CD8 and HLA-DR positive but failed to show CD30 antigen. DNA molecular analysis displayed simultaneous rearrangements of the genes coding for the delta chain of the T-cell receptor and for the Ig heavy chain. Increased serum levels of angiotensin converting enzyme and ferritin were found and probably induced by the reactive histiocytes. Immunoassays (ELISA) with antibodies directed against some cytokines and against the Tac peptide (sIL-2R) were performed. They demonstrated high serum levels of sIL-2R and a slight increase in GM-CSF, but neither IL-5 nor IL-3. The association of blood hypereosinophilia and histiocytic hyperplasia with a peripheral T-cell lymphoma is discussed.

Myelodysplastic syndrome with bone marrow eosinophilia: clinical and cytogenetic features

We investigated the hematological and clinical status of 145 patients with de novo myelodysplastic syndrome (MDS), 14 of whom (10%) had eosinophilia in the bone marrow (MDS-Eo). Most of these 14 patients had severe anemia. Their bone marrow cells exhibited trilineage dysplasia and some morphological abnormalities in the eosinophils, including disproportion of eosinophilic granules, basophilic granules, a ring-shaped nucleus, and vacuolation in the cytoplasm. However, these abnormalities were less prominent than those of acute myelomonocytic leukemia with eosinophilia (FAB: M4Eo). Three of the 14 MDS-Eo patients had refractory anemia (RA), seven had RA with excess of blasts (RAEB), and four had RAEB in transformation. Cytogenetic analysis revealed chromosomal abnormalities in 12 of 13 MDS-Eo patients (92%), in particular, there were major karyotypic abnormalities (MAKA) in eight patients (62%). Cytotoxic agents were not effective in the treatment of four patients after leukemic transformation occurred. These four patients died of the leukemic transformation while seven died of bone marrow failure. The other three MDS-Eo patients are still alive; two of them have already transformed to a leukemic phase. The duration of survival of these patients was significantly shorter than that of the other MDS patients. These findings suggest that bone marrow eosinophilia in MDS may be a poor prognostic factor that is strongly related to the existence of MAKA.

Increased plasma M-CSF concentration in patients with adult T cell leukemia: clinical correlation

Plasma concentration of M-CSF was measured in 35 patients with adult T cell leukemia (ATL), using a radioimmunoassay (RIA). ATL patients showed elevated levels of plasma M-CSF concentration when compared with healthy adult volunteers. Higher M-CSF levels were observed in acute ATL patients than in patients with chronic or smouldering ATL (P < 0.0001). There was a significant positive correlation of M-CSF concentration with serum lactic dehydrogenase (LDL) level, a reliable marker for assessing the grade of malignancy in ATL (P = 0.0003). There was, however, no correlation of M-CSF concentration with total counts of peripheral blood ATL cells, neutrophils or monocytes, or with serum calcium levels. Although there was a significant positive correlation of M-CSF concentration with body temperature (P = 0.003), there was not a significant correlation of M-CSF concentration with C-reactive protein (CRP), a protein indicative of the severity of inflammation (P = 0.063). These results indicate that plasma M-CSF concentration reflects the disease activity of ATL, and can thus serve as a marker in the clinical subclassification of ATL patients.