Arthritis syndromes associated with human T cell lymphotropic virus type I infection

HTLV-1 associated acute adult T-cell lymphoma/leukemia presenting as acute liver failure in Micronesian: A case report

RATIONALE

Malignant infiltration accounts for 0.5% of acute liver failure cases, with non-Hodgkin's lymphoma the predominant cause. Adult T-cell lymphoma/leukemia (ATLL) is a rarer source of acute hepatitis, with only 3 cases reported and all resulting in immediate deterioration with death. ATLL rises from human T-lymphocytic virus-1 (HTLV-1), commonly found in Japan (southern and northern islands), the Caribbean, Central and South America, intertropical Africa, Romania, and northern Iran. In Micronesia, HTLV-1 infection amongst native-born is absent or exceedingly rare.

PATIENT CONCERNS

A 77-year-old Marshallese man presented to the emergency department with a 1-week history of generalized weakness, fatigue, and nausea. The physical exam revealed a cervical papulonodular exanthem and scleral icterus.

DIAGNOSIS

Laboratory studies were remarkable for aspartate-aminotransferase of 230 IU/L (reference range [RR]: 0-40), alanine-aminotransferase of 227 IU/L (RR: 0-41), alkaline phosphatase of 133 IU/L (RR: 35-129), and total bilirubin of 4.7 mg/dL (RR: 0-1.2), supporting acute liver injury. Platelet count was 11.6x104/μL (RR: 15.1-42.4 × 104), hemoglobin was 13.8 g/dL (RR: 13.7-17.5), and white blood cell count was 7570/μL (RR: 3800-10,800) with 81.8% neutrophils (RR: 34.0-72.0) and 10.4% lymphocytes (RR: 12.0-44.0). The peripheral blood smear demonstrated abnormal lymphocytes with occasional flower cell morphology. HTLV-1/2 antibody tested positive. The skin and liver biopsies confirmed atypical T-cell infiltrate. The diagnosis of ATLL was established.

INTERVENTIONS

The patient elected for palliative chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP). He began antiviral treatment with zidovudine 250 mg bis in die (BID) indefinitely. Ursodiol and cholestyramine were added for his hyperbilirubinemia.

OUTCOMES

Four weeks from admission, the patient returned to near baseline functional status and was discharged home.

LESSONS

This case highlights that ATLL can initially present as isolated acute hepatitis, and how careful examination of peripheral blood-smear may elucidate hepatitis etiology. We also present support for utilizing ursodiol with cholestyramine for treating a hyperbilirubinemia. Moreover, unlike prior reports of ATLL presenting as liver dysfunction, combined antiviral and CVP chemotherapy was effective in this case. Lastly, there are seldom demographic reports of HTLV-1 infection from the Micronesian area, and our case represents the first indexed case of HTLV-1-associated-ATLL presenting as acute liver failure in a Marshallese patient.

Bilateral Wrist Tenosynovitis owing to Acute Conversion of Adult T-Cell Leukemia-Lymphoma in a Patient with Rheumatoid Arthritis

Human T-cell leukemia virus type 1- (HTLV-1-) associated arthritis is a relatively common disease. However, tenosynovitis owing to adult T-cell leukemia-lymphoma (ATL) is a rare condition. To the best of our knowledge, there have been no reports of tenosynovitis caused by conversion to acute ATL from one of the other ATL types. We present the case of a 60-year-old woman with rheumatoid arthritis (RA) with bilateral wrist tenosynovitis owing to the conversion to acute ATL from one of the other ATL types. She had swelling around the bilateral wrist joint under well controlled RA inflammation. She had no symptoms, physical findings, or laboratory findings indicative of conversion to acute ATL from one of the other ATL types. She underwent tenosynovectomy on the volar and dorsal sides of the left wrist joint to diagnose the cause of swelling around the bilateral wrist joint. Pathological analysis revealed diffuse proliferation of medium-sized atypical CD4(+) lymphocytes. Interestingly, she was diagnosed with wrist tenosynovitis caused by an acute ATL type. This diagnosis suggested that clinicians must consider ATL in connection with atypical wrist tenosynovitis in HTLV-1-endemic areas.

Palliative Radiation for Leukemic Arthropathy from Human T-Cell Lymphoma Virus-associated Adult T-Cell Leukemia Lymphoma

Human T-cell lymphoma virus (HTLV)-associated adult T-cell leukemia lymphoma is a rare cancer in the United States, but there are several areas around the world where the virus is endemic. HTLV-associated adult T-cell leukemia lymphoma has been associated with leukemic arthropathy. We present a patient with HTLV-associated adult T-cell leukemia lymphoma with leukemic arthropathy. Although non-steroidal anti-inflammatory drugs and chemotherapy are often used for treatment, we describe the successful use of radiation therapy in the palliative relief of symptoms from leukemic arthropathy.

Inflammatory manifestations of HTLV-1 and their therapeutic options

Human T lymphotropic virus type 1 (HTLV-1) is one of the most intriguing retroviruses infecting humans. Most commonly, infection remains undetected, since it does not cause obvious harm, yet in 4-9% of patients, this infection can be devastating, causing adult T-cell leukemia/lymphoma and/or HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). This review concentrates on all inflammatory aspects of HTLV-1 infection: HAM/TSP, HTLV-1 associated uveitis, HTLV-1 associated conjunctivitis, sicca syndrome and interstitial keratitis, HTLV-1 associated Sjögren's syndrome, Hashimoto's thyroiditis and Graves' disease, HTLV-1 associated pulmonary disease, infective dermatitis associated with HTLV-1, HTLV-1 associated inflammatory myositis and HTLV-1 associated arthritis. With the exception of HAM/TSP treatment, studies of these conditions are sparse and even for HAM/TSP, the level of evidence is limited. While control or elimination of infection remains a goal, most therapy beyond symptomatic management is directed at the immune response to HTLV-1.

A public HTLV-1 molecular epidemiology database for sequence management and data mining

BACKGROUND

It is estimated that 15 to 20 million people are infected with the human T-cell lymphotropic virus type 1 (HTLV-1). At present, there are more than 2,000 unique HTLV-1 isolate sequences published. A central database to aggregate sequence information from a range of epidemiological aspects including HTLV-1 infections, pathogenesis, origins, and evolutionary dynamics would be useful to scientists and physicians worldwide. Described here, we have developed a database that collects and annotates sequence data and can be accessed through a user-friendly search interface. The HTLV-1 Molecular Epidemiology Database website is available at http://htlv1db.bahia.fiocruz.br/.

METHODOLOGY/PRINCIPAL FINDINGS

All data was obtained from publications available at GenBank or through contact with the authors. The database was developed using Apache Webserver 2.1.6 and SGBD MySQL. The webpage interfaces were developed in HTML and sever-side scripting written in PHP. The HTLV-1 Molecular Epidemiology Database is hosted on the Gonçalo Moniz/FIOCRUZ Research Center server. There are currently 2,457 registered sequences with 2,024 (82.37%) of those sequences representing unique isolates. Of these sequences, 803 (39.67%) contain information about clinical status (TSP/HAM, 17.19%; ATL, 7.41%; asymptomatic, 12.89%; other diseases, 2.17%; and no information, 60.32%). Further, 7.26% of sequences contain information on patient gender while 5.23% of sequences provide the age of the patient.

CONCLUSIONS/SIGNIFICANCE

The HTLV-1 Molecular Epidemiology Database retrieves and stores annotated HTLV-1 proviral sequences from clinical, epidemiological, and geographical studies. The collected sequences and related information are now accessible on a publically available and user-friendly website. This open-access database will support clinical research and vaccine development related to viral genotype.

Viral arthritides

Viral infections may manifest as acute or chronic arthritis. Joint involvement arises from either direct infection of the joint, through an immunological response directed towards the virus or autoimmunity. Epidemiological clues to the diagnosis include geographic location and exposure to vector-borne, blood-borne or sexually transmitted viruses. Although not always possible, it is important to diagnose the pathogenic virus, usually by serology, nucleic acid tests or rarely, viral culture. In general, viral arthritides are self-limiting and treatment is targeted at symptomatic relief. This article focuses on the causes, clinical features, diagnosis and treatment of viral arthritides.

Epidemiology, treatment, and prevention of human T-cell leukemia virus type 1-associated diseases

Human T-cell leukemia virus type 1 (HTLV-1), the first human retrovirus to be discovered, is present in diverse regions of the world, where its infection is usually neglected in health care settings and by public health authorities. Since it is usually asymptomatic in the beginning of the infection and disease typically manifests later in life, silent transmission occurs, which is associated with sexual relations, breastfeeding, and blood transfusions. There are no prospects of vaccines, and screening of blood banks and in prenatal care settings is not universal. Therefore, its transmission is active in many areas such as parts of Africa, South and Central America, the Caribbean region, Asia, and Melanesia. It causes serious diseases in humans, including adult T-cell leukemia/lymphoma (ATL) and an incapacitating neurological disease (HTLV-associated myelopathy/tropical spastic paraparesis [HAM/TSP]) besides other afflictions such as uveitis, rheumatic syndromes, and predisposition to helminthic and bacterial infections, among others. These diseases are not curable as yet, and current treatments as well as new perspectives are discussed in the present review.

A case of human T lymphotropic virus type I-associated synovial swelling

BACKGROUND

Human T lymphotropic virus type 1 (HTLV-I) is associated with T-cell activation, proliferation, and leukemogenesis. HTLV-I is the causative agent of adult T cell leukemia/lymphoma and is associated with myelopathy/tropical spastic paraparesis, uveitis, polymyositis, synovitis, thyroiditis, and bronchoalveolar pneumonia. Since T-cell abnormalities are present in those infected with HTLV-I, the clinical problems might result from abnormal immune function or from direct leukemic or lymphomatous cell infiltration of tissues in the body. Distinguishing between these potential causes might be difficult in patients with joint involvement since the clinical findings can be similar. Consequently, obtaining synovial tissue for analyses is likely to be helpful in determining which process is causing the clinical symptoms.

INVESTIGATIONS

Physical examination, comprehensive metabolic panel, complete blood counts, urinalysis, serological testing for rheumatoid factor, antinuclear antibodies, hepatitis, and cytomegalovirus; western blot for HTLV-I/II, lymphocyte phenotyping of peripheral blood, polymerase chain reaction, plain radiographic imaging, CT, MRI skin biopsy with immunohistochemical analysis, lymph node biopsy with immunohistochemical analysis, lymphocyte phenotyping of synovial fluid, synovial tissue biopsy with immunohistochemical analysis of synovial tissue, and synovial tissue culture.

DIAGNOSIS

HTLV-I infected synovial cells in conjunction with leukemic/lymphomatous infiltration of synovial tissue.

MANAGEMENT

Chemotherapy protocol using alemtuzumab.

Molecular basis for HEF1/NEDD9/Cas-L action as a multifunctional co-ordinator of invasion, apoptosis and cell cycle

Upregulation of the scaffolding protein HEF1, also known as NEDD9 and Cas-L, has recently been identified as a pro-metastatic stimulus in a number of different solid tumors, and has also been strongly associated with pathogenesis of BCR-Abl-dependent tumors. As the evidence mounts for HEF1/NEDD9/Cas-L as a key player in metastatic cancer, it is timely to review the molecular regulation of HEF1/NEDD9/Cas-L. Most of the mortality associated with cancer arises from uncontrolled metastases, thus a better understanding of the properties of proteins specifically associated with promotion of this process may yield insights that improve cancer diagnosis and treatment. In this review, we summarize the extensive literature regarding HEF1/NEDD9/Cas-L expression and function in signaling relevant to cell attachment, migration, invasion, cell cycle, apoptosis, and oncogenic signal transduction. The complex function of HEF1/NEDD9/Cas-L revealed by this analysis leads us to propose a model in which alleviation of cell cycle checkpoints and acquired resistance to apoptosis is permissive for a HEF1/NEDD9/Cas-L-promoted pro-metastatic phenotype.

Human T-lymphotropic virus 1: recent knowledge about an ancient infection

Human T-lymphotropic virus 1 (HTLV-1) has infected human beings for thousands of years, but knowledge about the infection and its pathogenesis is only recently emerging. The virus can be transmitted from mother to child, through sexual contact, and through contaminated blood products. There are areas in Japan, sub-Saharan Africa, the Caribbean, and South America where more than 1% of the general population is infected. Although the majority of HTLV-1 carriers remain asymptomatic, the virus is associated with severe diseases that can be subdivided into three categories: neoplastic diseases (adult T-cell leukaemia/lymphoma), inflammatory syndromes (HTLV-1-associated myelopathy/tropical spastic paraparesis and uveitis among others), and opportunistic infections (including Strongyloides stercoralis hyperinfection and others). The understanding of the interaction between virus and host response has improved markedly, but there are still no clear surrogate markers for prognosis and there are few treatment options.

Detection of HTLV-I and -II in Scottish blood donor samples and archive donations

BACKGROUND AND OBJECTIVES

Positive samples identified during routine serological screening for HCV (hepatitis C virus), HBV (hepatitis B virus) and HIV (human immunodeficiency virus) are confirmed by nucleic acid testing in the SNBTS (Scottish National Blood Transfusion Service) PCR Reference laboratory. Serological screening for HTLV-I (human T-cell lymphotropic virus type I) and -II was implemented in Scotland in November 2002, at which time a PCR assay was not available for confirmation. Our aim was to develop a real-time PCR assay that could be used for the confirmation of samples showing HTLV-I serological positive or indeterminate reactivity and to investigate whether a serologically silent carrier status exists ('Tax' only) in the Scottish donor population.

MATERIALS AND METHODS

A real-time HTLV PCR was devised using a lymphoblastoid cell line which has HTLV-I sequence integrated in the genome (C8166 cells). These were spiked into peripheral blood mononuclear cells. The assay was evaluated on archived serologically confirmed HTLV-positive samples and new positives identified since implementation of screening.

RESULTS

HTLV-I and -II were detected in cells and plasma from stored donations and a serological positive donation identified in routine screening. HTLV DNA can also be amplified from the plasma obtained from plasma preparation tubes. There was no evidence of a carrier status ('Tax' only) in 100 serologically negative blood donors tested. The PCR assay developed is reliable and sensitive, capable of identifying one copy of HTLV-I.

CONCLUSIONS

The HTLV PCR is a useful addition for HTLV confirmation, especially in serologically indeterminate samples and for look-back studies. HTLV PCR confirmation will provide additional useful information for donor medical staff for counselling donors.

The human T-cell leukemia virus type 1 (HTLV-1): New insights into the clinical aspects and molecular pathogenesis of adult t-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-associated myelopathy (TSP/HAM)

Human T-cell leukemia virus type 1 (HTLV-1) was the first human retrovirus to be identified in the early 1980s. The isolation and identification of a related virus, HTLV-2, and the distantly related human immunodeficiency virus (HIV) immediately followed. Of the three retroviruses, two are associated definitively with specific diseases, HIV, with acquired immune deficiency syndrome (AIDS) and HTLV-1, with adult T-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM). While an estimated 10-20 million people worldwide are infected with HTLV-I, infection is endemic in the Caribbean, parts of Africa, southwestern Japan, and Italy. Approximately 4% of HTLV-I infected individuals develop ATLL, a disease with a poor prognosis. The clinical manifestations of infection and the current biology of HTLV viruses with emphasis on HTLV-1 are discussed in detail. The implications for improvements in diagnosis, treatment, intervention, and vaccination are included, as well as a discussion of the emergence of HTLV-1 and -2 as copathogens among HIV-1-infected individuals.

Global epidemiology of HTLV-I infection and associated diseases

Epidemiologic aspects of human T-lymphotropic virus type I (HTLV-I) infection have been thoroughly studied over the course of approximately 25 years since its first description. The geographic distribution of the virus has been defined, with Japan, Africa, Caribbean islands and South America emerging as the areas of highest prevalence. The reasons for HTLV-I clustering, such as the high ubiquity in southwestern Japan but low prevalence in neighboring regions of Korea, China and eastern Russia are still unknown. The major modes of transmission are well understood, although better quantitative data on the incidence of transmission, and on promoting/inhibiting factors, are needed. Epidemiologic proof has been obtained for HTLV-I's causative role in major disease associations: adult T-cell leukemia (ATL), HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), HTLV-associated uveitis and infective dermatitis. However, more and better studies are needed for other apparent disease outcomes such as rheumatologic, psychiatric and infectious diseases. Since curative treatment of ATL and HAM/TSP is lacking and a vaccine is unavailable, the social and financial cost for the individual, his/her family and the health system is immense. For this reason, public health interventions aimed at counseling and educating high-risk individuals and populations are of paramount importance.

Increased proviral load in HTLV-1-infected patients with rheumatoid arthritis or connective tissue disease

BACKGROUND

Human T-lymphotropic virus type 1 (HTLV-1) proviral load is related to the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and has also been shown to be elevated in the peripheral blood in HTLV-1-infected patients with uveitis or alveolitis. Increased proliferation of HTLV-1-infected cells in, or migration of such cells into, the central nervous system is also seen in HAM/TSP. In the present study, we evaluated the proviral load in a cohort of HTLV-1-infected patients with arthritic conditions.

RESULTS

HTLV-1 proviral load in the peripheral blood from 12 patients with RA and 6 patients with connective tissue disease was significantly higher than that in matched asymptomatic HTLV-1 carriers, but similar to that in matched HAM/TSP controls. HAM/TSP was seen in one-third of the HTLV-1-infected patients with RA or connective tissue disease, but did not account for the higher proviral load compared to the asymptomatic carrier group. The proviral load was increased in the synovial fluid and tissue from an HTLV-1-infected patient with RA, the values suggesting that the majority of infiltrated cells were HTLV-1-infected. In the peripheral blood from HTLV-1-infected patients with RA or connective tissue disease, HTLV-1 proviral load correlated with the percentages of memory CD4+ T cells and activated T cells, and these percentages were shown to be markedly higher in the synovial fluid than in the peripheral blood in an HTLV-1-infected patient with RA.

CONCLUSIONS

These biological findings are consistent with a role of the retrovirus in the development of arthritis in HTLV-1-infected patients. A high level of HTLV-1-infected lymphocytes in the peripheral blood and their accumulation in situ might play a central role in the pathogenesis of HTLV-1-associated inflammatory disorders. Alternatively, the autoimmune arthritis, its etiological factors or treatments might secondarily enhance HTLV-1 proviral load.

Respiratory and urinary tract infections, arthritis, and asthma associated with HTLV-I and HTLV-II infection

Human T-lymphotropic virus types I and II (HTLV-I and -II) cause myelopathy; HTLV-I, but not HTLV-II, causes adult T-cell leukemia. Whether HTLV-II is associated with other diseases is unknown. Using survival analysis, we studied medical history data from a prospective cohort of HTLV-I– and HTLV-II–infected and –uninfected blood donors, all HIV seronegative. A total of 152 HTLV-I, 387 HTLV-II, and 799 uninfected donors were enrolled and followed for a median of 4.4, 4.3, and 4.4 years, respectively. HTLV-II participants had significantly increased incidences of acute bronchitis (incidence ratio [IR] = 1.68), bladder or kidney infection (IR = 1.55), arthritis (IR = 2.66), and asthma (IR = 3.28), and a borderline increase in pneumonia (IR = 1.82, 95% confidence interval [CI] 0.98 to 3.38). HTLV-I participants had significantly increased incidences of bladder or kidney infection (IR = 1.82), and arthritis (IR = 2.84). We conclude that HTLV-II infection may inhibit immunologic responses to respiratory infections and that both HTLV-I and -II may induce inflammatory or autoimmune reactions.

Critical role of human T-lymphotropic virus type 1 accessory proteins in viral replication and pathogenesis

Human T-cell lymphotropic virus type 1 (HTLV-1) infection is associated with a diverse range of lymphoproliferative and neurodegenerative diseases, yet pathogenic mechanisms induced by the virus remain obscure. This complex retrovirus contains typical structural and enzymatic genes but also unique regulatory and accessory genes in four open reading frames (ORFs) of the pX region of the viral genome (pX ORFs I to IV). The regulatory proteins encoded by pX ORFs III and IV, Tax and Rex, respectively, have been extensively characterized. In contrast the contribution of the four accessory proteins p12(I), p27(I), p13(II), and p30(II), encoded by pX ORFs I and II, to viral replication and pathogenesis remained unclear. Proviral clones that are mutated in either pX ORF I or II, while fully competent in cell culture, are severely limited in their replicative capacity in a rabbit model. Emerging evidence indicates that the HTLV-1 accessory proteins are critical for establishment of viral infectivity, enhance T-lymphocyte activation, and potentially alter gene transcription and mitochondrial function. HTLV-1 pX ORF I expression is critical to the viral infectivity in resting primary lymphocytes, suggesting a role for p12(I) in lymphocyte activation. The endoplasmic reticulum and cis-Golgi localizing p12(I), encoded from pX ORF I, activates NFAT, a key T-cell transcription factor, through calcium-mediated signaling pathways and may lower the threshold of lymphocyte activation via the JAK/STAT pathway. In contrast p30(II) localizes to the nucleus and represses viral promoter activity, but may regulate cellular gene expression through p300/CBP or related coactivators of transcription. p13(II) targets mitochondrial proteins, where it alters the organelle morphology and may influence energy metabolism. Collectively, studies of the molecular functions of the HTLV-1 accessory proteins provide insight into strategies used by retroviruses that are associated with lymphoproliferative diseases.

Non-HIV retroviral associations with rheumatic disease

While the human T-cell lymphotropic virus type I (HTLV-I) is the recognized cause of adult T cell leukemia, it is also associated with non-neoplastic, ostensibly autoimmune conditions, such as tropical spastic paraparesis. Moreover,among carriers of HTLV-I, the virus is strongly implicated in the development of a type of arthritis, which resembles rheumatoid arthritis (RA). Mice transgenic for HTLV-I tax develop RA-like pathology and Sjögren's syndrome. Patients with RA and SS in HTLV-I nonendemic regions, such as the United States, are usually serologically negative for antibodies to the structural proteins of HTLV. However, they appear to harbor HTLV-I tax in their peripheral blood mononuclear cells three times as often as individuals who present as healthy blood donors. Because HTLV-I tax transactivates numerous inflammatory cytokines and is not normally found in the human genome, treatment with tax antisense oligonucleotides may provide a new therapeutic approach for selected RA patients proven to be HTLV-I "tax only" positive.

Seropositive polyarthritis and skin manifestations in T-prolymphocytic leukemia/Sezary cell leukemia variant

Sezary cell leukemia (SCL) is a rare T cell neoplasia that has been suggested to be a variant of T-prolymphocytic leukemia (T-PLL). Both disorders have an aggressive clinical course, lymphocytosis with characteristic morphology, lymphadenopathy, hepatomegaly, characteristic cytogenetic abnormalities and mature T cell phenotypes. Skin lesions, however, are mainly found in T-PLL. We describe a patient with T-PLL/SCL, who atypically presented with severe seropositive polyarthritis and skin lesions, responding to treatment with human CD52 antibody, CAMPATH-1H and pentostatin. Meningeal leukemia and an assumed myocardial infiltration subsequently developed. Polyarthritis is common in T large granular lymphocyte leukemia and adult T cell lymphoma-leukemia, but both entities could be ruled out in the present case. In rheumatoid arthritis, an expansion of CD4+ and/or CD8+ T lymphocytes is well documented and this phenomenon is believed to be of pathogenetic importance. We speculate that the T cell clone in the present case had special homing properties or cytokine effects resulting in synovitis.

Osteitis fibrosa cystica generalizata with adult T-cell leukaemia: a case report

We report on a 62-year-old female initially suffering from extreme pain in both her lower extremities. Plain radiographs revealed multiple osteolytic lesions. Laboratory analyses indicated high levels of serum calcium and parathyroid hormone related protein (PTHrP) and detected HTLV-1 antibody. Histological examination of biopsied specimens which were obtained from osteolytic lesions indicated osteitis fibrosa cystica (OFC) without tumour cells. After the initial biopsy, a subcutaneous mass developed in the left thigh. Microsections of the biopsied mass disclosed adult T-cell leukaemia (ATL) neoplastic cells. Immunohistochemical findings revealed that PTHrP secreted from ATL neoplastic cells induced the OFC.

Rheumatologic features of hematologic disorders

This review focuses on the various rheumatologic manifestations of hematologic diseases and is based on the English literature published over the past year. Interrelationships between leukemia, lymphoma, POEMS syndrome, multiple myeloma, hemophilia, and rheumatic manifestations are discussed. Other less common associated conditions dealt with include the RS3PE syndrome, large granular lymphocyte syndrome, and interferon-related arthritis. Finally, therapeutic measures, such as bone marrow transplantation and the use of granulocyte colony-stimulating factor, are reviewed.

HTLV-1 and Adult T-Cell Leukemia/Lymphoma: A Review

Infection with the human T-lymphotropic virus type 1 (HTLV-1) has been shown to be fundamental to the etiology of Adult T-cell Leukemia/Lymphoma (ATL). The disease is endemic in specific geographic areas but is increasingly reported from non-endemic regions. With increasing number of patients with this entity, the diversity in the clinical features has become apparent. In the past treatment strategies using combination chemotherapy have been unsatisfactory, but more recent trials using adenosine analouges, interferons, and combination of interferons and AZT have shown promise. With increased understanding of the etiology and molecular basis of the disease more effective therapies can be anticipated.