Adult T-cell leukemia/lymphoma in the Middle East: first report of two cases from Lebanon

BACKGROUND: Adult T-cell leukemia/lymphoma (ATL) is an aggressive lymphoproliferative disorder caused by human T-cell leukemia virus type I (HTLV-I). HTLV-I is endemic in southern Japan, the Caribbean, Central and South America, certain areas of Africa, and the southeastern United States. In the Middle East, North East Iran, particularly the region of Mashhad, has been recognized as an endemic region.
CASE REPORTS: In this report, the first two cases of ATL diagnosed in Lebanon are described. The first patient of Lebanese origin presented with acute ATL. The second patient of Romanian origin developed acute ATL in early relapse after autologous transplantation for ATL. Both patients had lymphocytosis, severe hypercalcemia, and CD25+ T-cell immunophenotype on peripheral blood. In both patients, HTLV-I serology was positive by enzyme-linked immunosorbent assay and confirmed by Western blot and HTLV-I oncoprotein Tax expression was documented in the leukemic cells. Upon screening, seven direct family members of the first patient were HTLV-I positive; four of them were regular blood donors.
CONCLUSIONS: Screening blood donors for HTLV-I seropositivity is not currently performed in Lebanon. A large screening study in Lebanon is needed to confirm whether South Lebanon is a new endemic region for HTLV-I infection and to recommend mandatory screening of blood donors for HTLV-I infection.     

九例成人T淋巴细胞白血病的临床与实验研究

目的探讨成人Ｔ淋巴细胞白血病（ＡＴＬ）的临床、细胞学、免疫学、细胞遗传学、血清学及分子生物学等特征。方法采用间接免疫荧光法及酶联免疫吸附法检测血清ＨＴＬＶⅠ抗体,建立ＰＣＲ和液相杂交法检测前病毒基因序列,结合ＭＩＣ特征确诊ＡＴＬ。结果和结论确诊９例ＡＴＬ,其临床特征主要为淋巴结肿大,皮损及溶骨改变少见,外周血及骨髓出现典型的花瓣状核淋巴细胞,胞体大,核畸形,免疫表型为ＣＤ－１、ＣＤ＋２、ＣＤ３＋、ＣＤ４＋、ＣＤ－８,还表达ＣＤ２５等激活标记,染色体核型及ＨＬＡ分型未发现有规律性的变化。８例ＡＴＬ中有７例血清ＨＴＬＶⅠ抗体阳性,应用ＰＣＲ及液相杂交法可检出整合到宿主细胞ＤＮＡ中的ＨＴＬＶⅠ病毒序列,表明在我国ＨＴＬＶⅠ也是ＡＴＬ的病因。９例中１例为淋巴瘤型,１例为慢性型,７例为急性型ＡＴＬ,治疗效果及预后均不良     

Assessment of abdominal involvement of adult T-cell leukemia/lymphoma by ultrasonography: comparison among four clinical types.

Adult T-cell leukemia/lymphoma (ATLL) is an HTLV-I associated lymphoid malignancy frequently seen in Japan. Abdominal involvement in 40 patients with ATLL were assessed by ultrasonography and the findings seen in four clinical types, acute, chronic, lymphoma and smoldering, were compared. Splenomegaly was frequently found in the cases of acute and lymphoma types, and the sizes of the spleens measured by ultrasonography correlated well with the disease activity. Hepatomegaly was also found more frequently in acute and lymphoma types, and hepatosplenomegaly was proved to be due to the infiltration by ATL cells. Nodular lesions in spleen and liver and abdominal lymph node swelling were also found frequently in the lymphoma type but rarely in the other types. Ascites, pleural effusion, and pericardial effusion were found in the active stage of acute and lymphoma types. Ultransonography also could detect findings associated with therapies. Thus, ultrasonography studies were found to be very useful for assessing the clinical classification, examining various pathological conditions associated with ATLL, and monitoring the disease activity.     

Close association between interleukin 2 receptor mRNA expression and human T cell leukemia/lymphoma virus type I viral RNA expression in short-term cultured leukemic cells from adult T cell leukemia patients.

Human T cell leukemia/lymphoma (T-lymphotropic) virus type I (HTLV-I) infection has been considered to be closely associated with the leukemogenesis of adult T cell leukemia (ATL), in which interleukin 2 (IL-2) receptors are abnormally expressed. In this study, however, Southern blot analysis revealed no gross rearrangement or obvious amplification of the IL-2 receptor gene in ATL leukemic cells, indicating that abnormal IL-2 receptor expression in ATL is not due to the structural change of its gene. Hence, we studied the expression of the IL-2 receptor and HTLV-I at the RNA level during short-term cultures of leukemic cells from 9 ATL patients. Cytoplasmic dot hybridization and Northern hybridization revealed that fresh leukemic cells from seven of nine patients expressed a small amount of IL-2 receptor mRNA but HTLV-I RNA was undetectable in all cases. After cultures for up to 7 d, both IL-2 receptor mRNA and HTLV-I RNA (including pX message) expression concomitantly increased, whereas the amounts of other cellular genes, except for beta-actin, did not. The increases in their RNA expression were inhibited by early addition (within 12 h after the beginning of the culture) of cycloheximide, indicating that these increases are mediated by newly synthesized protein(s). These results strongly suggested that IL-2 receptor expression is closely associated with HTLV-I expression in leukemic cells from ATL patients.     

NIK-333 inhibits growth of human T-cell leukemia virus type I-infected T-cell lines and adult T-cell leukemia cells in association with blockade of nuclear factor-kappaB signal pathway

Adult T-cell leukemia (ATL) is caused by human T-cell leukemia virus type I (HTLV-I) and remains incurable. NIK-333, a novel synthetic retinoid, prevents the recurrence of human hepatoma after surgical resection of primary tumors. We explored the effects of NIK-333 on HTLV-I-infected T-cell lines and ATL cells. NIK-333 inhibited cell proliferation, induced G1 arrest, and resulted in massive apoptosis in all tested HTLV-I-infected T-cell lines and ATL cells, whereas little effect was observed on normal peripheral blood mononuclear cells. NIK-333 treatment decreases the levels of cyclin D1, cyclin D2, cIAP2, and XIAP proteins. Further analysis showed that NIK-333 inactivated nuclear factor-kappaB in HTLV-I-infected T-cell lines. In animal studies, treatment with NIK-333 (100 mg/kg given orally every other day) produced partial inhibition of growth of tumors of a HTLV-I-infected T-cell line transplanted s.c. in severe combined immunodeficient mice. Our results indicate that NIK-333 is a potentially useful therapeutic agent for patients with ATL.     

Elevated serum levels of soluble interleukin-2 receptors in HTLV-I--associated myelopathy

Using an enzyme-linked immunosorbent assay, we measured the level of soluble interleukin-2 receptors (sIL-2Rs) in the serum of 50 normal controls, 48 human carriers of T cell leukemia virus type I (HTLV-I) antibody who had no symptoms, 11 patients with HTLV-I-associated myelopathy (HAM), and 39 patients with adult T cell leukemia (ATL) (four smoldering, 10 chronic, nine lymphoma, and 16 acute type). The highest levels of sIL-2R were observed in patients with acute and lymphoma-type ATL, as opposed to those with chronic and smoldering-type ATL. The levels of sIL-2R in patients with HAM were roughly between those of smoldering ATL and healthy HTLV-I carriers. Serum sIL-2R levels in healthy carriers were also elevated compared with those in normal controls. These observations suggest that the measurement of sIL-2R levels in patients with ATL can be useful as a noninvasive measure of tumor burden and should aid in the understanding of the natural history of HTLV-I infection leading to the development of ATL.     

Interleukin-2 receptor (Tac antigen) expressed on adult T cell leukemia cells.

We studied the expression of the interleukin-2 (IL-2) receptor and the proliferative response to exogenous IL-2 of peripheral blood leukemic cells from patients with adult T cell leukemia (ATL) in order to see whether IL-2 receptor expressed on ATL cells is different from normal IL-2 receptor and whether it plays a role in the neoplastic growth in ATL. Peripheral blood leukemic cells from 42 patients with ATL examined expressed IL-2 receptors that were detected by anti-Tac monoclonal antibody when examined immediately after the separation of cells or after the culture for 24 or 48 h. The number of anti-Tac binding sites ranged from 3,100 to 11,400 in fresh cells and from 3,600 to 96,000/cell in short-term cultured leukemic cells, whereas phytohemagglutinin-P (PHA-P)-stimulated normal T cells exhibited 6,900-35,000 anti-Tac binding sites per cell. ATL-derived and human T cell leukemia/lymphoma virus, type I (HTLV-I)-infected cell lines such as MT-1 and Hut102 expressed a much higher number of anti-Tac binding sites. Leukemic cells from 15 patients with ATL examined showed no or very poor proliferative response to various concentrations of immunoaffinity-purified IL-2, although they expressed Tac antigen (Ag). Radiolabeled IL-2 binding experiments demonstrated that ATL leukemic cells could bind IL-2, and they expressed both high and low affinity IL-2 receptors, although the number of high affinity IL-2 receptor was much less than that of low affinity IL-2 receptor and that of anti-Tac binding sites. In contrast, leukemic T cells from a patient with T cell chronic lymphocytic leukemia (CLL), in whom HTLV-I infection was not demonstrated, responded as well as PHA-P-stimulated normal T cells, and their IL-2 receptors, unlike ATL cells, were modulated (down regulated) by anti-Tac antibody. No differences were noted between ATL cells and normal activated T cells in one-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the IL-2 receptor. Thus, leukemic cells in ATL spontaneously and continuously express IL-2 receptor, which appears to be abnormally regulated and unresponsive to IL-2. These results, taken together with those on normal IL-2 receptors on HTLV-I-negative T-CLL cells, suggest that abnormal expression of the IL-2 receptor in ATL is closely associated with HTLV-I infection and may play a role in the neoplastic growth of ATL cells.     

Therapy-induced selective loss of leukemia-initiating activity in murine adult T cell leukemia

Chronic HTLV-I (human T cell lymphotropic virus type I) infection may cause adult T cell leukemia/lymphoma (ATL), a disease with dismal long-term prognosis. The HTLV-I transactivator, Tax, initiates ATL in transgenic mice. In this study, we demonstrate that an As(2)O(3) and IFN-α combination, known to trigger Tax proteolysis, cures Tax-driven ATL in mice. Unexpectedly, this combination therapy abrogated initial leukemia engraftment into secondary recipients, whereas the primary tumor bulk still grew in the primary hosts, only to ultimately abate later on. This loss of initial transplantability required proteasome function. A similar regimen recently yielded unprecedented disease control in human ATL. Our demonstration that this drug combination targeting Tax stability abrogates tumor cell immortality but not short-term growth may foretell a favorable long-term efficiency of this regimen in patients.     

Screening blood products for HTLV-I: what is the best approach?

A recent concern for disease transmission by blood transfusion is T-lymphotropic virus type I (HTLV-I). This virus is endemic in Japan, the Caribbean basin, subsaharan Africa, and, to a lesser extent, the southeastern United States and parts of Central and South America. HTLV-I, which has been shown to be transmitted via transfusion, is associated with adult T-cell leukemia (ATL) and certain degenerative neurological disorders. Antibodies to HTLV-I, an indicator of exposure to the virus, have been demonstrated in 0.025% of healthy U.S. donors. This study, using the Decision Tree Model, presents an approach to a donor screening policy which should be cost-effective and yet ensure a safe blood supply.     

Hypercalcemia and T-cell lymphoma with acquired immunodeficiency syndrome: occurrence without human T-cell leukemia virus-I

We describe the case of a patient with acquired immunodeficiency syndrome (AIDS) who had a CD4 cell count of 60/microL, bilateral hilar adenopathy, and hypercalcemia. Transbronchial biopsy showed T-cell anaplastic large cell lymphoma. Serology was negative for human T-cell leukemia virus-I (HTLV-I). This appears to be the first case of T-cell anaplastic large cell lymphoma occurring in an AIDS patient with hypercalcemia who was seronegative for HTLV-I.     

Adult T cell leukemia/lymphoma (ATL)

Adult T cell leukemia/lymphoma(ATL) is an aggressive, fatal malignancy associated with human T-lymphotropic virus type I(HTLV-I). The median survival time of acute- and lymphoma-type ATL is 6 and 10 months, respectively. According to recent reports, nearly half of the ATL patients who received allogeneic hematopoietic stem cell transplantation could survive without disease for over 3 years. However, the population of patients who are eligible for conventional transplantation is extremely limited. Therefore, a reduced-intensity allogeneic stem cell transplantation(RIST) is applied to ATL patients and a multi-center phase I clinical trial is now underway. In our institute, 5 patients, who received RIST, are all alive, with 1 case relapsed after 6 months. Thus, RIST is considered very promising.     

Synthesis of proteins in Escherichia coli immunoreactive with sera from individuals infected with human T-cell leukemia virus type I

The env-pX IV fused gene of human T-cell leukemia virus type I (HTLV-I) was inserted into lac promoter-directed expression vectors for production of viral proteins in bacteria. Resulting recombinant plasmids, pK13 and pK15, directed synthesis of fused proteins of 59 kDa (Env-p40x) and 100 kDa (Gag-Env-p40x), respectively. Western blot analysis showed that these proteins were reactive with sera of patients with adult T-cell leukemia (ATL) and retained multiple antigenic determinants of viral proteins. In combination with recombinant Gag protein [S. Itamura, K. Shigesada, M. Imai, N. Kobayashi, T. Hamakado, T. Harada and M. Hatanaka, Gene 38, 57-64 (1985)], these bacterially synthesized proteins may provide a useful tool for differential diagnosis of ATL by detecting serum antibodies against individual viral proteins and for analysis of viral gene functions.     

AZ960, a novel Jak2 inhibitor, induces growth arrest and apoptosis in adult T-cell leukemia cells

Adult T-cell leukemia/lymphoma (ATL) is a highly aggressive disease in which the Jak2/Stat5 pathway is constitutively activated. This study found that AZ960, a novel inhibitor of Jak2 kinase, effectively induced growth arrest and apoptosis of human T-cell lymphotropic virus type 1, HTLV-1-infected T cells (MT-1 and MT-2) in parallel with downregulation of the phosphorylated forms of Jak2 and Bcl-2 family proteins including Bcl-2 and Mcl-1. Interestingly, AZ960 increased levels of Bcl-xL in MT-1 and MT-2 cells in association with accumulation of cAMP response element-binding protein bound to the Bcl-xL promoter as measured by chromatin immunoprecipitation assay. Importantly, genetic inhibition of Bcl-xL by a small interfering RNA potentiated antiproliferative effects of AZ960 in MT-1 cells. Taken together, Jak2 is an attractive molecular target for treatment of ATL. Concomitant blockade of Jak2 and Bcl-xL may be a promising treatment strategy for this lethal disease.     

A Review of New Findings in Adult T-cell Leukemia–Lymphoma: A Focus on Current and Emerging Treatment Strategies

Adult T-cell leukemia–lymphoma (ATL), a rare and aggressive T-cell malignancy caused by human T-cell lymphotropic virus type 1 (HTLV-1), is associated with a poor prognosis. Evidence-based standard treatment options are lacking and outcomes are generally unsatisfactory, particularly for patients with relapsed or refractory disease. Continued research is contributing to changing treatment landscape as a number of existing and investigational agents are evaluated. We describe the epidemiology of HTLV-1 and ATL, discuss the biology behind the disease, review current treatment practices and guidelines, and provide an overview of emerging therapies in ATL, with a focus on those for relapsed or refractory disease.     

Rat lymphoid cell lines producing human T cell leukemia virus. II. Constitutive expression of rat interleukin 2 receptor

Three rat lymphoid cell lines (TARS-1, TARL-2, and TART-1) (12) transformed by human T cell leukemia/lymphoma virus I (HTLV-I) had rearrangement of the beta chain gene of the T cell antigen receptor, and had integrated proviral DNA from HTLV-I in their genomes. As is the case with adult T cell leukemia (ATL)-derived human T cell lines transformed by HTLV-I, these rat cell lines unequivocally expressed interleukin 2 (IL-2) receptor, as determined by radiolabeled IL-2 binding. By Scatchard plot analysis, one of the cell lines, TART-1, proved to have high affinity receptors (Ka = 1.3 X 10(11)/M and 8.8 X 10(9)/M). Rat IL-2 receptor, not human IL-2 receptor, was expressed on HTLV+ rat cell lines, as demonstrated by the fact that they expressed antigens reactive with monoclonal antibodies (ART-18) against rat IL-2 receptor, but not with anti-Tac antibodies. The collective evidence indicates that the endogenous IL-2 receptor gene is activated in human and rat lymphoid cell lines with HTLV-I production. The mechanism of abnormal IL-2 receptor expression in HTLV infection is discussed.     

Human T-cell lymphotrophic virus type-I (HTLV-I) retrovirus and human disease

Human T-cell lymphotrophic virus type-I (HTLV-I) was the first pathogenic retrovirus identified in humans. HTLV-I is now linked to a number of clinical diseases, most notably adult T-cell leukemia/lymphoma and the syndrome known as HTLV-associated myelopathy or tropical spastic paraparesis (HAM/TSP). For the emergency physician practicing among patients from high-risk groups, HTLV-I infection and its associated diseases are presenting an increasing challenge. This report describes its transmission, seroprevalence, associated diseases, and methods to control the spread of this retrovirus.     

Origin of human T-lymphotrophic virus I-positive T cell lines in adult T cell leukemia. Analysis of T cell receptor gene rearrangement

Using the clone-specific rearrangement of the T cell receptor gene as the genetic marker of the clonotype, we analyzed the clonal origin of the interleukin 2 (IL-2)-dependent human T-lymphotrophic virus I (HTLV-I)-positive T cell lines established from various adult T cell leukemia (ATL) patients. From a patient with chronic ATL, whose leukemic cells proliferated in vitro in response to IL-2, we repeatedly established leukemic T cell clones having the same rearrangement profile of the T beta chain gene as the leukemic cells. By contrast, established cell lines from acute ATL patients had different beta chain gene rearrangements from those of the leukemic cells. These HTLV-I+ T cell lines might not be the direct progeny of the leukemic cells, but that of T cells infected either in vivo or in vitro. These IL-2-reactive nonleukemic T cells might have been selected in vitro, because their leukemic cells failed to respond to IL-2, despite the expression of IL-2 receptor. The analysis of the T cell receptor gene rearrangement may give a new approach for the elucidation of the mechanism of leukemogenesis and the origin of the HTLV-I+ T cell lines in ATL.     

Interleukin 1 gene expression in adult T cell leukemia.

The adult T cell leukemia (ATL) is a T cell neoplasm etiologically associated with human T lymphotropic virus type I (HTLV-I) infection. ATL cells often abnormally express interleukin 2 (IL-2) receptors, and ATL patients may show clinical evidence of hypercalcemia, osteolytic bone lesions, or increased bone turnover. Whereas interleukin 1 (IL-1) is not generally recognized as a product of T cells, this cytokine is capable of both altering IL-2 receptor expression and activating osteoclasts. Thus, we investigated the possibility that primary ATL leukemic T cells and HTLV-I-infected long-term ATL cell lines produce IL-1. S1 nuclease protection assays demonstrated that primary leukemic ATL cells from five out of six patients, as well as one patient with T4+ chronic lymphocytic leukemia, contained considerable quantities of IL-1 beta messenger RNA (mRNA) and small amounts of IL-1 alpha mRNA. These primary leukemic T cells also released biologically active IL-1 protein as evaluated in the murine thymocyte comitogenesis bioassay. In contrast to primary tumor cells, four out of six long-term ATL cell lines produced variable amounts of IL-1 alpha mRNA in the absence of detectable IL-1 beta mRNA as measured by S1 nuclease protection. These data demonstrate that IL-1 gene (especially IL-1 beta) expression occurs in many primary HTLV-I-infected leukemic T cells raising the possibility that this mediator may play a role in the pathological changes associated with this leukemia. Also, these studies show that the pattern of IL-1 alpha and IL-1 beta gene expression differs between primary ATL tumor cells and long-term cultured ATL cell lines, indicating an interesting biological difference in these two HTLV-I-infected cell populations.     

Absence of human T-lymphotropic virus types I and II infection in an Ontario hemophilia population

Two hundred ninety-three serum samples from Ontario hemophiliacs and 200 samples from human immunodeficiency virus-positive blood donors were screened for the presence of antibodies to human T-lymphotropic virus type I (HTLV-I) by enzyme-linked immunosorbent assay, radioimmunoassay, and Western blot techniques. None of the serum samples provided unequivocal positive results, but several samples gave inconclusive results. Of the hemophiliacs with inconclusive serologic results from whom peripheral blood lymphocyte DNA could be obtained, all were negative for HTLV-I and HTLV type II (HTLV-II) sequences as determined by polymerase chain reaction (PCR). PCR was also performed on a lymph node biopsy sample taken from a hemophiliac who developed a rare T-cell lymphoma; the sample was negative for HTLV-I and -II sequences. These results indicate that Ontario hemophiliacs have not been exposed to HTLV-I or HTLV-II.     

Mogamulizumab, a humanized mAb against C-C chemokine receptor 4 for the potential treatment of T-cell lymphomas and asthma

Mogamulizumab (KW-0761; AMG-761), under development by Kyowa Hakko Kirin and Amgen, is a defucosylated humanized IgG1 mAb against C-C chemokine receptor 4 (CCR4) for the potential intravenous treatment of T-cell lymphomas and asthma. Chemokines and their receptors are signaling molecules constitutively responsible for lymphocyte and neutrophil chemotaxis, which can also be involved in pathogenic mechanisms of various diseases. In particular, CCR4 has been demonstrated to play a major role in adult T-cell leukemia/lymphoma (ATL), in which it is a marker of poor prognosis. Consequently, CCR4 blockade might have therapeutic potential in treating ATL, a disease that is most often aggressive in course, and for which existing therapies are not always effective. Mogamulizumab reduced tumor load via enhanced antibody-dependent cell cytotoxicity in preclinical studies and demonstrated promising efficacy in early clinical trials in patients with ATL. In addition, CCR4 also has a role in maintaining T-helper cell type 2 airways inflammation in asthma, and Amgen have acquired the rights to develop mogamulizumab for this indication and other non-oncology indications; however, at the time of publication, no data were available from Amgen's investigations. This is a review on the potential use of mogamulizumab for the treatment of T-cell lymphomas and asthma, with specific emphasis on the treatment of ATL.