Human T-cell leukemia virus type I associated lymphadenitis

Functional properties and sequence variation of HTLV-1 p13

Human T cell leukemia virus type-1 (HTLV-1) was the first retrovirus found to cause cancer in humans, but the mechanisms that drive the development of leukemia and other diseases associated with HTLV-1 infection remain to be fully understood. This review describes the functional properties of p13, an 87-amino acid protein coded by HTLV-1 open reading frame II (orf-II). p13 is mainly localized in the inner membrane of the mitochondria, where it induces potassium (K⁺) influx and reactive oxygen species (ROS) production, which can trigger either proliferation or apoptosis, depending on the ROS setpoint of the cell. Recent evidence indicates that p13 may influence the cell’s innate immune response to viral infection and the infected cell phenotype. Association of the HTLV-1 transcriptional activator, Tax, with p13 increases p13’s stability, leads to its partial co-localization with Tax in nuclear speckles, and reduces the ability of Tax to interact with the transcription cofactor CBP/p300. Comparison of p13 sequences isolated from HTLV-1-infected individuals revealed a small number of amino acid variations in the domains controlling the subcellular localization of the protein. Disruptive mutations of p13 were found in samples obtained from asymptomatic patients with low proviral load. p13 sequences of HTLV-1 subtype C isolates from indigenous Australian patients showed a high degree of identity among each other, with all samples containing a pattern of 5 amino acids that distinguished them from other subtypes. Further characterization of p13’s functional properties and sequence variants may lead to a deeper understanding of the impact of p13 as a contributor to the clinical manifestations of HTLV-1 infection.

The Role of Chemokines in the Pathogenesis of HTLV-1

Human T cell leukemia virus type 1 (HTLV-1) is a human retrovirus that is associated with two main diseases: HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and adult T cell leukemia/lymphoma (ATL). Chemokines are highly specialized groups of cytokines that play important roles in organizing, trafficking, homing, and in the migration of immune cells to the bone marrow, lymphoid organs and sites of infection and inflammation. Aberrant expression or function of chemokines, or their receptors, has been linked to the protection against or susceptibility to specific infectious diseases, as well as increased the risk of autoimmune diseases and malignancy. Chemokines and their receptors participate in pathogenesis of HTLV-1 associated diseases from inflammation in the central nervous system (CNS) which occurs in cases of HAM/TSP to T cell immortalization and tissue infiltration observed in ATL patients. Chemokines represent viable effective prognostic biomarkers for HTLV-1-associated diseases which provide the early identification of high-risk, treatment possibilities and high-yielding clinical trials. This review focuses on the emerging roles of these molecules in the outcome of HTLV-1-associated diseases.

Clinical usefulness of FDG-PET/CT for the evaluation of various types of adult T-cell leukemia

PURPOSE

The aim was to explore undefined useful indices for clinically grading adult T-cell leukemia (ATL) using [¹⁸F] 2-fluoro-2-deoxyglucose (FDG) - positron emission tomography/computed tomography (PET/CT).

METHODS

A total of 28 patients with ATL (indolent, 9; aggressive, 19) were enrolled; all patients with aggressive ATL underwent FDG-PET/CT before chemotherapy. Patients with indolent ATL underwent FDG-PET/CT at the time of suspected disease progression and/or transformation; some received lymph node biopsy. The quantitative parameters maximum standardized uptake values (SUVmax), and mean and peak SUV, metabolic tumor volume (MTV), and volume-based total lesion glycolysis were calculated with the margin threshold as 25%, and 50% of the SUVmax for all lesions.

RESULTS

All parameters except for MTV-25% showed significant differences (P ≤ 0.05) in differentiating the aggressive type from the indolent type of ATL. Areas under the curve for receiver-operating characteristic (ROC) analysis regarding the series of parameters investigated ranged from 0.75 to 0.92; this indicated relatively high accuracy in distinguishing the aggressive type from the indolent type. No malignant findings were detected in lymph node biopsies in indolent ATL patients with lymphadenopathy.

DISCUSSION

We performed evaluation of a line of parameters of FDG-PET, thereby demonstrating their significantly high accuracy for grading malignancy in ATL patients. In particular, low accumulation of FDG in indolent ATL patients with lymphadenopathy might predict that it is not a sign of disease transformation, but rather a reactive manifestation.

CONCLUSION

FDG-PET/CT findings could be useful for clinically grading ATL.

EBV-positive diffuse large B-cell lymphoma in a human T-lymphotropic virus type 1 carrier

The development of B-cell lymphomas has been seldom described in HTLV-1 carriers. We present the case of an elderly Peruvian HTLV-1 carrier who was diagnosed with EBV-positive diffuse large B-cell lymphoma. Despite an initial good response to therapy, patient died during treatment due to fatal Pneumocystis jirovecci pneumonia. EBV infection is characterized by B-cell lymphotropism and selective immunodeficiency. HTLV-1, on the other hand, induces T-cell dysfunction and B-cell proliferation. Finally, immunosenescence is characterized by T-cell dysregulation, decreased apoptosis and cytokine upregulation. In this elderly patient, the combination of EBV and HTLV-1 coinfection and immunosenescence may have played a role in the development of this aggressive diffuse large B-cell lymphoma. Furthermore, the immunodeficiency caused by the viral infections and chemotherapy may have played a role in developing life-threatening infectious complications.

Upregulation of CC chemokine ligand 18 and downregulation of CX3C chemokine receptor 1 expression in human T-cell leukemia virus type 1-associated lymph node lesions: Results of chemokine and chemokine receptor DNA chip analysis

Adult T-cell leukemia/lymphoma (ATLL) is a human malignancy associated with human T-cell leukemia virus type 1 (HTLV-1). The pathological features of the lymph nodes of ATLL change from those of lymphadenitis to Hodgkin's-like features and those of lymphoma. Chemokines and their receptors are closely associated with T-cell subgroups and immune responses. To clarify the relationship between chemokines and their receptor expression, as well as the development of ATLL, 17 cases with ATLL were analyzed using DNA chips of chemokines and their receptors. All cases showed a varied and mixed pattern of upregulated and downregulated gene expression of Th1, Th2, naïve, and cytotoxic cell-associated chemokine genes. As CC chemokine ligand 18 (CCL18) accounted for the most upregulated gene and CX3C chemokine receptor 1 (CX3CR1) for the most downregulated gene, they were selected for immunohistochemical analysis. Immunohistochemical staining showed expression of the two genes in immunological cells, with a positive expression for reticulum cells, but not for ATLL cells. HTLV-1-associated lymphadenitis type (n = 13) and Hodgkin's-like type (n = 12) cases showed significantly higher CCL18 expression than the non-specific lymphadenitis cases (n = 10) (P < 0.05). However, all HTLV-1-associated cases showed significantly lower CX3CR1 expression than the non-specific lymphadenitis cases (P < 0.05). These results suggest that upregulation of CCL18 expression and downregulation of CX3CR1 expression play a role in immune responses against the ATLL cells.

Pathological features of diseases associated with human T-cell leukemia virus type I

In the early 1980s, the first human retrovirus, human T-cell leukemia virus type I (HTLV-I), was isolated and its characterization opened up the new field of human viral oncology. Adult T-cell leukemia/lymphoma (ATLL), which is associated with HTLV-I, is characterized clinically by the appearance of characteristic flower cells, a rapid clinical course, occasional skin lesions, lymphadenopathy and hepatosplenomegaly. Severe opportunistic infections are occasionally accompanied. In addition, HTLV-I infection is associated with autoimmune and reactive disorders, such as HTLV-I-associated myelopathy and uveitis, and is also related to immunodeficient infectious diseases. Pathological findings of ATLL in the lymph nodes, skin, liver and other organs have been described. Common histological features are a diffuse proliferation of atypical lymphoid cells that vary in size and shape. In addition to ATLL, non-neoplastic organopathies have been documented in many organs, such as the central nerve system, lung, skin, lymph nodes and gastrointestinal tract. To clarify the HTLV-I-associated diseases, it is important to understand the pathological variations.

Pattern-reversal visual evoked potentials in patients with human T-lymphotropic virus type 1 uveitis

PURPOSE

The purpose of this study was to evaluate the possible injury in the optic pathway by measuring P100 peak latency of pattern-reversal visual evoked potentials (PVEPs) in patients with human T-lymphotropic virus type 1 uveitis (HU).

METHODS

The P100 peak latency of PVEP was measured during the period without macular abnormalities observed by fluorescein angiography in 23 patients (46 eyes) with HU and 24 patients (48 eyes) with Vogt-Koyanagi-Harada disease (VKH) with a corrected visual acuity of 20/25 or more. To determine the normal upper limit of P100 peak latency, PVEPs were measured in 31 normal subjects (31 eyes). In addition, in the HU patients, the serum anti-HTLV-1 antibody titer was measured by particle agglutination assay within 3 months of PVEP recording, and the period of HU was retrospectively surveyed.

RESULTS

Delayed latency was observed in 4 (7 eyes) of the 23 patients (46 eyes) with HU but none of the 24 patients (48 eyes) with VKH. All four patients with delayed latency showed a serum anti-HTLV-1 antibody titer of more than x4000. The HU period in the HU patients was 0.2-14.0 years, and the HU periods in the four patients with delayed latency were 0.8, 2.7, 4.2, and 14.0 years, respectively.

CONCLUSIONS

We measured pattern-reversal visual evoked potentials and observed delayed P100 peak latency in 7 of the 46 eyes in 4 (17.4%) of the 23 HU patients. This suggests injury in the optic pathway including the optic nerve by HTLV-1 in some patients with HU. In the future, consideration should also be given to the possible development of optic neuropathy due to HTLV-1.

Burkitt lymphoma of the uterus in a human T lymphotropic virus type-1 carrier

A 71-year-old Japanese woman who was seropositive for T-lymphotropic virus type-1 (HTLV-1) developed primary Burkitt lymphoma of the uterus. CT showed marked enlargement of the uterine body. Chromosomal abnormalities were detected in biopsied cells, and most showed the t (8; 14) (q24; q32) translocation. Fluorescence in situ hybridization (FISH) with a dual-color stain for IgH/C-MYC fusion showed 99% positively. Biopsies from abdominal operation were diagnosed as Burkitt lymphoma. Treatment was started with intensive chemotherapy according to a protocol for Burkitt lymphoma and mature-B cell leukemia. Two regimens were done with four courses with rituximab. Treatment response was fast, with a documented and lasting first complete remission on CT and laboratory markers after the 4 cycle treatment.

HTLV-1 carriers with B-cell lymphoma of localized stage head and neck: prognosis, clinical and immunopathological features

Human T-lymphotropic virus type I (HTLV-I) is closely associated with T-cell lymphoma/leukaemia, which always shows monoclonal HTLV-1 provirus DNA integration. HTLV-1 is not associated with B-cell lymphoma. The relationship between B-cell lymphoma and HTLV-1 was analysed retrospectively in early stage B-cell non-Hodgkin's lymphoma (NHL) according to HTLV-1 infection and pathological features. We analysed 198 cases of head and neck B-cell NHL treated with radiotherapy and/or chemotherapy; 21 were seropositive and 177 were seronegative for HTLV-1. We also immunostained 26 cases of diffuse large B-cell lymphoma (DLBL), including 12 seropositive and 14 seronegative for HTLV-1 respectively, for CD20, CD3, CD4, CD8, CD56, MIB-1 and T-cell-restricted intracellular antigen (TIA-1) to examine the phenotype, immunity and proliferation activity. The 5-year overall survival rates were 78% and 49% (P = 0.007, log rank test) for HTLV-1 seronegative and seropositive cases respectively. Infection with HTLV-1 was significantly associated with poor survival in patients with B-cell lymphoma by multivariate analysis. For DLBL, HTLV-1 infection was not a significant factor, but the overall survival curve was similar to that of the 21 seropositive B-cell lymphoma cases. Lymphoma cells were negative for TIA-1, but the background lymphocytes were positive for this marker. The number of TIA-1-positive cells was higher in HTLV-1-negative cases than in-positive cases. In conclusion, patients with B-cell-NHL (B-NHL) who are also HTLV-1 carriers have a poorer prognosis than non-carriers. HTLV-1 does not seem to be associated with lymphomagenesis of the B phenotype itself, but correlates with host immunity by reducing the number of cytotoxic T-cells.

Survival of patients with HTLV-I-associated lymph node lesions

Adult T-cell leukaemia/lymphoma (ATLL), is a malignant condition associated with human T-cell leukaemia virus type I (HTLV-I). Usually, although not uniformly, histopathological examination of the lymph nodes shows a pleomorphic type. In addition, some patients with pre-overt ATLL show a Hodgkin's disease-like morphology and lymph nodes in non-neoplastic carriers show features of lymphadenitis. To characterize further the clinicopathological features of HTLV-I-associated lymphadenopathy, the histopathological features of the lymph nodes of 289 patients were classified into five types: lymphadenitis ( n=14), Hodgkin's-like (Hodgkin's) ( n=18), pleomorphic (medium and large cells) ( n=219), pleomorphic small cell ( n=11), and anaplastic large cell (ALC) ( n=27). Survival data were analysed according to the histopathological features of the lymph nodes. The pleomorphic type, which showed typical features of ATLL, was associated with a highly aggressive course and an initially high mortality, followed by a rapid decrease in survival. This pattern was also observed in patients with the ALC type. All cases with lymphadenitis were still alive at the end of the study, while survival progressively decreased in the Hodgkin's type. The small cell type showed an initial rapid decrease in survival followed by a plateau. These results show that the survival trends of patients with pleomorphic and anaplastic lymph node lesions are similar to those with ATL lymphoma, while patients with the lymphadenitis type of lesion were considered to have a non-neoplatic status. There is at present no effective therapy for ATLL, but in the future, these classification and survival data might be useful for the selection of appropriate chemotherapeutic regimens for patients with ATLL.

Molecular pathologic analysis of the tonsil in HTLV-I-infected individuals

Little is known about the role of the tonsils in HTLV-I infection. We performed molecular pathologic studies of tonsils in individuals positive or negative for anti-HTLV-I antibodies (HTLV-I-Ab) to clarify histologic characteristics of tonsils in HTLV-I infection. We collected tonsils and peripheral blood samples from patients who underwent tonsillectomy in a prospective manner. HTLV-I-Ab in serum was examined and presence of HTLV-I provirus was detected by polymerase chain reaction (PCR) in extracted DNA of both peripheral blood and tonsils. Histopathologic and immunohistochemical evaluations of tonsils were performed. HTLV-I seropositivity and PCR detection of HTLV-I provirus matched perfectly. Tonsil samples from seropositive individuals showed atrophy of the mantle zone and high numbers of T cells in the marginal zone compared with findings in HTLV-I-negative samples. HTLV-I provirus could be detected only from extracted DNA of extrafollicular areas. PCR in situ hybridization also showed positive signals in some mononuclear cells located in the marginal zone. There was a significant correlation between HTLV-I proviral load in tonsils and in peripheral blood. These results suggest the presence of characteristic histologic changes and deviated localization of HTLV-I-infected cells in the tonsils of individuals positive for HTLV-I.

Clonal integration and expression of human T-cell lymphotropic virus type I in carriers detected by polymerase chain reaction and inverse PCR

Adult T-cell leukemia (ATL) is a neoplasm of mature helper (CD4) T lymphocytes, and human T-cell lymphotropic virus type-I (HTLV-I) has been suggested to be the causative virus of ATL. HTLV-I integrates its proviruses into random sites in host chromosomal DNA. Clonal integration has been observed in patients with ATL, including smoldering, chronic, and acute states. However, random and/or polyclonal integration has only been reported in a few asymptomatic HTLV-I carriers. To clarify the clonality of HTLV-I-infected cells in carriers, we used an inverse polymerase chain reaction (IPCR), which is more sensitive than Southern blot analysis. We used the peripheral blood momonuclear cells (PBMC) from 16 asymptomatic carriers and the separated CD4-positive cells. No cases showed either a monoclonal or polyclonal integration of the HTLV-I provirus by Southern blot. But, using IPCR, 7 of 16 cases showed either mono- or oligoclonal integration. In addition, the populations of clonal provirus in the total PBMC were frequently different from those in the CD4-positive cells. Three cases showed expression of HTLV-I tax/rex mRNA in the total PBMC, but no such expression was found in CD4-positive cells. In this study, an unexpected frequency of clonal HTLV-I provirus DNA was observed in HTLV-I carriers. These findings indicate that the clonal but nonmalignant proliferation of HTLV-I-infected cells already occurs even in HTLV-I carriers, and therefore that some other step is necessary to induce malignant proliferation.

Physical and functional interaction between the human T-cell lymphotropic virus type 1 Tax1 protein and the CCAAT binding protein NF-Y

Tax1, a potent activator of human T-cell lymphotropic virus type 1 (HTLV-1) transcription, has been shown to modulate expression of many cellular genes. Tax1 does not bind DNA directly but regulates transcription through protein-protein interactions with sequence-specific transcription factors. Using the yeast two-hybrid system to screen for proteins which interact with Tax1, we isolated the B subunit of the CCAAT binding protein NF-Y from a HeLa cDNA library. The interaction of Tax1 with NF-YB was specific in that NF-YB did not interact with a variety of other transcription factors, including human immunodeficiency virus Tat, human papillomavirus E6, and Bicoid, or with the M7 (amino acids 29CP-AS) Tax1 mutant. However, NF-YB did interact with the C-terminal Tax1 mutants M22 (130TL-AS) and M47 (319LL-RS). We also show that in vitro-translated NF-YB specifically bound to a glutathione S-transferase-Tax1 fusion protein. Further, Tax1 coimmunoprecipitated with NF-Y from nuclear extracts of HTLV-1-transformed cells, providing evidence for in vivo interaction of Tax1 and NF-YB. We further demonstrate that Tax1 specifically activated the NF-Y-responsive DQbeta promoter, as well as a minimal promoter which contains only the Y-box element. In addition, mutation of the Y-box element alone abrogated Tax1-mediated activation. Taken together, these data indicate that Tax1 interacts with NF-Y through the B subunit and that this interaction results in activation of the major histocompatibility complex class II promoter. Through activation of this and other NF-Y driven promoters, the Tax1-NF-Y interaction may play a critical role in causing cellular transformation and HTLV-1 pathogenesis.

Human T cell leukemia virus type I (HTLV-I) and human diseases

HTLV-I infection is causally associated with a variety of human diseases including leukemia/lymphoma, myelopathy, uveitis, and arthropathy. Tax protein of HTLV-I, which is considered oncogenic, binds to transcription factors or other cytoplasmic cellular molecules involved in the fundamental cell function and thereby induces cellular changes. The interaction between HTLV-I-infected cells with dysregulated function and different kinds of cells in the host, such as lymphocytes and vascular endothelial cells through viral peptides, antigen receptors cell adhesion molecules, and cytokines, appears to be one of the basic mechanisms underlying the development of HTLV-I-associated diseases. This interaction may play a major role in determining tumorigenicity and in forming clinical features of the diseases. The in vivo cell proliferation model of HTLV-I-infected cells using severe combined immunodeficient (SCID) mice can differentiate tumorigenicity from cell immortalization in vitro. The OX40 and its ligand gp34, which are induced by HTLV-I infection and directly mediate the adhesion between HTLV-I-infected T cells and vascular endothelial cells, may be critically involved in the localization and proliferation of HTLV-I-infected cells in vivo.

ATL and HTLV-I: in vivo cell growth of ATL cells

The mechanism of leukemogenesis or neoplastic cell growth in adult T cell leukemia (ATL) still remains unclear, although Tax of human T cell leukemia/lymphoma virus type I (HTLV-I), the etiologic virus, has been reported to affect the expression of various cellular genes which encode molecules involved in cell growth or cell death. We have studied the cell growth of HTLV-I-infected human T cells in severe combined immunodeficiency (SCID) mice and found that fresh leukemic cells or cell lines derived from leukemic cell clones but not HTLV-I-infected cell lines of nonleukemic cell origin showed tumorigenicity, and neither HTLV-I nor IL-2 expression was needed for cell growth in vivo, indicating that accumulating changes in addition to the initial events induced by HTLV-I infection were required for the development of ATL. The interaction between ATL cells and vascular endothelial cells appears to be one of the important factors which determine the pattern of organ infiltration by leukemic cells. E-selectin and its ligand are one of the major cell adhesion pathways between ATL cells and human umbilical vein endothelial cells (HUVEC). Another pathway that had not been identified was studied using newly developed monoclonal antibodies capable of blocking cell adhesion. The molecules which directly mediate adhesion between ATL cells and HUVEC were determined to be OX40 and gp34, a member of the tumor necrosis factor receptor (TNF-R) family and TNF family, respectively. The OX40/gp34 system may play a key role in the trafficking and homing of not only ATL cells but also activated normal T cells.

Random suppression of T cells that bear specific T cell receptor V beta sequences in adult T cell leukemia/lymphoma (ATLL) patients at each clinical stage: carrier, smoldering, chronic, and acute

Human T cell leukemia virus type I (HTLV-I) is associated with adult T cell leukemia/lymphoma (ATLL), which is well known as a T cell malignancy. In order to clarify whether HTLV-I plays a role as a virus-encoded superantigen in the neoplastic process, we examined the TCR V beta families in the peripheral blood at four different clinical stages: carrier, smoldering leukemia, chronic leukemia, and acute leukemia. An increased number of CD4 T cells was found in each of the four clinical stages. However, we found neither uniform specific losses nor uniform clonal expansion of particular TCR V beta gene families in any case from the four clinical stages. However, a suppression of the random TCR V beta families was found. Our data did not therefore directly suggest the existence of a common superantigen model of HTLV-I which induces an increase in CD4 T cells. The random suppression in the TCR V beta repertoire is most likely caused by the influence of HTLV-I neoplastic pathogenesis rather than by virus-encoded superantigens. In the patients with acute leukemia, one or two families of the V beta repertoires were very strongly expressed, while in chronic leukemia, no such repertoire of strong expression was observed. The immunological reaction of the hosts might thus be different between the above described groups.

Detection of human T-lymphotropic virus type-I DNA and mRNA in the lymph nodes; using polymerase chain reaction in situ hybridization (PCR/ISH) and reverse transcription (RT-PCR/ISH)

To examine the relationship between human T-lymphotrophic virus type I (HTLV-I) proviral DNA and its expression in the lymph nodes, HTLV-I DNA and tax/rex mRDA were directly amplified by polymerase chain reaction in situ hybridization (PCR/ISH), and reverse transcription (RT)-PCR/ISH [RT-PCR/ISH]. We studied 24 lymph nodes from patients with adult T-cell leukemia/lymphoma (ATLL), incipient ATLL (I-ATLL), and HTLV-I associated lymphadenitis dermatopathic type (HAL-D) and enlarged paracortical type (HAL-EP). In ATLL, 40-60% of the nucleated cells were positive for for HTLV-I proviral DNA by PCR/ISH, while in I-ATLL and HAL, respectively 5-20% and less than 1-5% of cells were positive. The number of mRNA expressing cells was smaller than that of the proviral DNA-positive cells. The mRNA-expressing cells varied in number among the ATLL and I-ATLL cases, while they were only rarely observed in HAL-D and HAL-EP. These results show that HTLV-I infection and activation might increase with malignant transformation of the target T helper cells.

Mechanisms of Tax Regulation of Human T Cell Leukemia Virus Type I Gene Expression

During the last several years, the human T cell leukemia virus type I (HTLV-I) has become recognized as an important cause for public health concern throughout the world. HTLV-I is the causative agent of a variety of clinical diseases, including an aggressive lymphoproliferative disorder named adult T cell leukemia. HTLV-I induces pathogenicity in the infected host cell through the synthesis of a virally encoded protein called Tax. Expression of Tax is critical to the life cycle of the virus, as the protein greatly increases the efficiency of HTLV-I gene transcription and replication. Furthermore, Tax has been shown to deregulate the transcription of many cellular genes, leading to the hypothesis that the presence of Tax promotes unchecked growth in the HTLV-I-infected cell. The mechanism of Tax trans-activation of HTLV-I gene expression is not known. Tax does not bind directly to the Tax-responsive promoter elements of the virus, but appears to function through interaction with certain cellular DNA binding proteins, including activating transcription factor 2 and cAMP response element binding protein that recognize these sequences. This review summarizes some of the recent work in the field aimed at elucidating the mechanism of Tax trans-activation of HTLV-I gene expression. Copyright 1995 S. Karger AG, Basel

Clinicopathological features of adult T-cell leukemia with CD30 antigen expression

Recently, several cases of adult T-cell leukemia (ATL) with CD30 antigen have been reported, but its clinical significance remains unknown. Accordingly, we studied CD30 antigen expression in ATL cases and documented the clinicopathological characteristics of these cases. Immunohistochemical and clinical characteristics were studied in 46 patients with malignant lymphoma or benign lesions of lymphoid tissue, who had antibodies against human T-cell leukemia virus type I (HTLV-I). Monoclonal integration of HTLV-I provirus was demonstrated in the tumor cells in 36 (ATL) of the 46 cases. CD30 antigen expression was evident in seven of these 36 cases (19.4%), however it was not seen in any of the ten cases lacking the integration of HTLV-I provirus. A comparison of ATL cases with and without CD30 antigen expression revealed significantly larger numbers of abnormal lymphocytes in the peripheral blood and lower serum calcium levels in ATL expressing CD30 antigen.

Clonality of benign lymphoid hyperplasia in orbit and conjunctiva

In order to thoroughly characterize the clonal population of lymphoid hyperplasia of the orbit and conjunctiva, we investigated six cases which were histologically proven to be benign lymphoid hyperplasia. We analyzed the clonal rearrangements of the antigen receptors and bcl-2 gene, Epstein-Barr virus (EBV), and human T-cell leukemia virus type 1 (HTLV-I) by Southern blot and/or polymerase chain reaction (PCR), and performed in situ hybridization for mRNA of kappa and lambda immunoglobulin. Five cases showed rearrangements of immunoglobulin heavy chain gene (JH) and/or light chain gene (J kappa), and the monoclonal V-J recombination of JH in PCR. However, the rearranged bands were much more faint than was the germ-line band. We considered the monoclonal population of B cells small. Two of the five cases recurred locally after four and nine years respectively. Because benign lymphoid hyperplasias frequently contain an occult monoclonal B-cell population, a follow-up should be conducted. The remaining case in our investigation showed a rearrangement of the T-cell-receptor gene and proviral DNA of HTLV-I, and it showed rapid progress to adult T-cell leukemia after the biopsy. EBV and bcl-2 gene rearrangements were not observed in any of the six cases we studied.

Human T-lymphotropic virus type I in Japan

Adult T-cell leukaemia (ATL) was first reported in Japan, where it has a high incidence in the southwest region. The retrovirus human T-lymphotropic virus type I (HTLV-I) is the cause of ATL; and in ATL-endemic areas, the rate of carriage of antibodies to HTLV-I is high. A definite diagnosis of ATL is based on the presence of HTLV-I proviral DNA in the tumour-cell DNA. ATL cells originate from the CD4 subset of peripheral T cells. ATL shows diverse clinical features but can be divided into four subtypes--acute, chronic, smouldering, and lymphoma type. It is resistant to chemotherapy, and the acute and lymphoma types have a poor prognosis. Familial occurrence of ATL is common. HTLV-I infection is caused by transmission of live infected lymphocytes from mother to child, from man to woman, or by transfusion. Infection with HTLV-I can lead to other diseases, including HTLV-I-associated myelopathy/tropical spastic paraparesis and HTLV-I uveitis, possibly via induction of immunodeficiency or hyperreactivity against HTLV-I-infected cells.

Adult T cell leukaemia-lymphoma

Adult T cell leukaemia-lymphoma (ATL) was first discovered and reported in Japan, where it has a high incidence in the south-west region. The first human retrovirus HTLV-I (human T-cell lymphotropic virus type I) is considered to be related to its aetiology. In ATL endemic areas, HTLV-I carriers form a fairly high percentage of the population, even among healthy individuals. ATL shows diverse clinical features. It can be divided into four subtypes: acute, chronic, smouldering and lymphoma type. ATL cells originate from the CD4-positive subset of peripheral T cells; they show a characteristic notch in the nucleus and a tendency to lobulation. ATL resists chemotherapy, and patients with acute and lymphoma types have a fairly poor prognosis. A definite diagnosis of ATL is made by documenting the presence of HTLV-I proviral DNA in the DNA of tumour cells. HTLV-I infection is caused by transmission of live lymphocytes via three routes (from mother to child, from males to females, and by transfusion). Familial occurrence of ATL is frequently seen. HTLV-I infection is seen in other countries, but its incidence is highest in Japan. Infection with HTLV-I is a direct cause of ATL. Furthermore, infection with this virus can indirectly cause many other diseases via the induction of immunodeficiency, such as chronic lung disease, opportunistic lung infection, cancer of other organs, monoclonal gammopathy, chronic renal failure, strongyloidiasis, non-specific dermatomycosis, HTLV-I-associated lymphadenitis, HTLV-I uveitis and HTLV-I-associated myelopathy-tropical spastic paraparesis (HAM/TSP).

Restriction of T cell receptor variable region in lymph nodes of adult T cell leukemia/lymphoma

Adult T cell leukemia/lymphoma (ATLL) is a mature T cell malignancy, especially derived from the CD4 positive T cell. To characterize the T cell, we examined the representation of T cell antigen receptor variable region, using the monoclonal antibodies [beta V 5 (a), beta V 5 (b), beta V 6 (a), beta V 8 (a), beta V 12 (a), alpha V 2 (a), alpha-beta V (a)]. Clinicopathologically we classified the lymph nodes of patients with ATLL into three states (1) human T cell leukemia virus type I (HTLV-I) associated lymphadenitis, reactive state; (2) incipient ATLL, early or pre-neoplastic state; and (3) ATLL, neoplastic state. The lymph nodes of all three states were composed of unvarying CD4 positive T cells. Most of the lymph nodes with ATLL consistently presented alpha V 2 antigen, but no others. In HTLV-I associated lymphadenitis, only a few cells reacted for alpha V 2, as in non-specific lymphadenitis without ATLL features. One of three cases with incipient ATLL presented alpha V 2. The selected expression of T cell antigen receptor V region might be associated with the presence of HTLV-I encoded superantigen, similar to human immunodeficiency virus (HIV).

The presence of particles resembling human T-cell leukemia virus type I at ultrastructural examination of lymphomatous cells in a case of T-cell leukemia/lymphoma

BACKGROUND

Cases of adult T-cell leukemia/lymphoma (ATLL) resulting from human T-cell leukemia virus type I (HTLV-I) have been observed mainly in the southern part of Japan. Recently, the authors performed a second examination of cutaneous, muscle, and nerve biopsy specimens from a French white woman who died of ATLL in 1979.

METHODS

A 67-year-old white woman had a lymphoma diagnosed on a lymph node biopsy. She then had acute pains and a thickened skin on both legs. Blood examination showed a leukocyte count of 16,000/ml with 75% leukemia T-cells. Biopsies were performed on the antero-external surface of the right leg. She died after 2 years of illness.

RESULTS

Lymphomatous infiltrates of T-cell origin were seen in the dermis, between muscle fibers, and in a peripheral nerve. The recent ultrastructural examination of a few vacuoles located in the cytoplasm of certain lymphomatous cells showed rounded structures mixed with larger virus-like formations having a central nucleoid and spike material around the envelope. Polymerase chain reaction experiments performed on deparaffinized sections demonstrated the presence of a tax sequence homologous to that of HTLV-I. Other structural genes were not detected.

CONCLUSIONS

These results contrast with other ultrastructural studies in which HTLV-I was detected only after cultivation of leukemia cells from patients with ATLL. This case probably resulted from an HTLV-I variant.