Human T-cell leukemia virus type 1 may invalidate T-SPOT.TB assay results in rheumatoid arthritis patients: A retrospective case-control observational study.

BACKGROUND: CD4-positive T cells are the main target of human T-cell leukemia virus type 1 (HTLV-1). Interferon-γ release assays rely on the fact that T-lymphocytes release this cytokine when exposed to tuberculosis-specific antigens and are useful in testing for latent tuberculosis infection before initiating biologic therapy, such as anti-tumor necrosis factor agents. However, the reliability of interferon-γ release assays in detecting tuberculosis infection among HTLV-1-positive patients with rheumatoid arthritis (RA) remains unclear. The present study aimed to evaluate the use of the T-SPOT.TB assay in HTLV-1-positive RA patients. METHODS: Overall, 29 HTLV-1-positive RA patients and 87 age- and sex-matched HTLV-1-negative RA patients (controls) were included from the HTLV-1 RA Miyazaki Cohort Study. Results of the T-SPOT.TB assay for latent tuberculosis infection screening were collected from medical records of patients. RESULTS: Approximately 55% of the HTLV-1-positive RA patients showed invalid T-SPOT.TB assay results (odds ratio: 108, 95% confidence interval: 13.1-890, p < 0.0001) owing to a spot count of >10 in the negative controls. HTLV-1 proviral load values were significantly higher in patients with invalid results compared with those without invalid results (p = 0.003). CONCLUSION: HTLV-1 infection affects T-SPOT.TB assay results in RA patients. Assay results in HTLV-1 endemic regions should be interpreted with caution when screening for latent tuberculosis infection before initiation of biologic therapy.

Meningitis associated with strongyloidiasis in an area endemic for strongyloidiasis and human T-lymphotropic virus-1: a single-center experience in Japan between 1990 and 2010.

Meningitis caused by enteric flora is a known complication of strongyloidiasis, and human T-lymphotropic virus-1 (HTLV-1) predisposes individuals to severe strongyloidiasis. We reviewed the clinical features of bacterial meningitis associated with strongyloidiasis seen at a single center in subtropical Japan, in an area endemic for both strongyloidiasis and HTLV-1. We found 33 episodes in 21 patients between 1990 and 2010. The results were remarkable for the high incidence of meningitis due to Gram-positive cocci (27.3 %), especially Streptococcus bovis, and culture-negative cases (42.4 %). Given the high incidence of Gram-positive meningitis, a modified approach to corticosteroid use would be advisable in areas where strongyloidiasis is endemic, due to the potentially adverse consequences of glucocorticoid therapy.

Human T-lymphotropic virus type 1 infective dermatitis in central Australia.

The Human T-Lymphotropic Virus type 1 (HTLV-1) is a single-stranded RNA retrovirus that preferentially infects CD4+ T cells. The spectrum of diseases that are associated with the most frequent genotype, the HTLV-1 cosmopolitan subtype A, has been well described. In contrast, very few cases of HTLV-1 related diseases have been reported for the HTLV-1 subtype C variant, which is endemic to Australia and the nearby islands of Melanesia. Here we describe the first case of infective dermatitis associated with the HTLV-1 Australo-Melanesian subtype C. This was complicated by repeated episodes of invasive infection with Staphylococcus aureus and illustrates the life-threatening nature of infective dermatitis among HTLV-1 carriers who live in conditions of social disadvantage.

Tuberculous meningoencephalomyelitis and coinfection with HTLV-I + HTLV-II: case report.

HTLV-I and HTLV-II are endemic in some areas of Brazil, where an associated disease, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) have been diagnosed in significant number of infected individuals. Tuberculosis has been demonstrated among those individuals, with higher prevalence than in the general population, suggesting that there is an increased risk for this comorbidity. We report the case of an individual coinfected with HTLV-I and HTLV-II, suffering from an insidious meningoencephalomyelitis caused by Mycobacterium tuberculosis. The patient was a 44 years old man successfully treated with steroids and antituberculous drugs, improving clinically and turning to a negative PCR and to a normal blood-cerebrospinal fluid barrier.

Tuberculous meningoencephalomyelitis and coinfection with HTLV-I + HTLV-II: case report

Os vírus HTLV-I e HTLV-II são endêmicos em algumas regiões do Brasil, onde uma das doenças associadas, a paraparesia espástica tropical/mielopatia associada ao HTLV (PET/MAH), tem sido diagnosticada em significativo número de pacientes infectados. Nesses indivíduos, a prevalência de tuberculose é maior que na população geral, sugerindo que possa haver um maior risco para esta comorbidade. Relatamos o caso de um homem de 44 anos coinfectado HTLV-I + HTLV-II que desenvolveu meningoencefalomielite por Mycobacterium tuberculosis. O paciente apresentou recuperação clínica parcial, correção da disfunção de barreira hemato-liquórica e negativação no PCR, mediante o tratamento com corticoesteróides e tuberculostáticos.

Human T-lymphotropic virus type I infection and idiopathic thrombocytopnic purpura.

Human T-lymphotropic virus type I (HTLV-I) is the causative agent in adult T-cell leukemia and HTLV-I associated myelopathy. Some other diseases such as uveitis, chronic thyroiditis, Sjögren syndrome, arthritis, acute myeloid leukemia and myelodysplastic syndrome may be also associated with HTLV-I. Several case reports have suggested the possible combination of idiopathic thrombocytopenic purpura (ITP) and HTLV-I infection. In these studies and from our current report, we found 17 patients (22.1%) with HTLV-I infection among 77 ITP patients. The prevalence of HTLV-I infection among ITP patients was higher than that of healthy volunteers (5 approximately 10%). The ITP patients with HTLV-I infection were older than the patients without HTLV-I infection, and the ITP patients with HTLV-I infection had poor response to prednisolone therapy. Among 17 ITP patients with HTLV-I infection, 9 patients received prednisolone therapy. Although most patients had transient increase of platelet counts, only two of them had partial responses (PR) at the last observation date. Five patients underwent splenectomy, and four of them had complete responses (CR) and the remaining patient had a (PR). Four patients received eradication of Helicobactor pylori (H. pylori) infection, and all patients had CRs. Therefore, the ITP patients with HTLV-I infection should receive eradication therapy in the case of H. pylori infection as the first step of therapy and the splenectomy should be considered, if there is no response to conventional therapy. Human immunodeficiency virus (HIV) causes thrombocytopenia in 10% of patients with active HIV disease. The etiologies of HIV thrombocytopenia are considered as follows, the escalated destruction of platelets by the immune system, damage to megakaryocytes by HIV infection and the inhibition of thrombopoiesis by some anti-viral drugs. In the case of ITP patients with HTLV-I infection, the main etiology may be the increased destruction of platelets by immune system. The proviral load and the integration pattern of HTLV-I should be examined to clarify the stage of HTLV-I infection. The possibility of infection of the megakaryocytes by HTLV-I should be also examined for etiological approach.

Predictive markers for development of strongyloidiasis in patients infected with both Strongyloides stercoralis and HTLV-1.

Severe strongyloidiasis has often been reported to occur in some patients infected with both Strongyloides stercoralis (S. stercoralis) and human T-cell leukaemia virus type 1 (HTLV-1); however, there are few useful predictive markers for the risk of development of strongyloidiasis in these patients. To search for such predictive markers, we examined peripheral blood and stool samples of individuals infected with both S. stercoralis and HTLV-1 in Okinawa, Japan, an area in which both of these are endemic. The HTLV-1 proviral load and antibody titre were examined in relation to the S. stercoralis load as measured by the direct faecal smear method in patients infected with both S. stercoralis and HTLV-1. The Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA) antibody titre was also measured in these patients in order to examine the relationship between host immunity and HTLV-1 proviral load or antibody titre. The direct faecal smear-positive group showed both a higher HTLV-1 proviral load and HTLV-1 antibody titre than the -negative group (P < 0.05). In contrast, inverse correlations of these parameters with the EBNA antibody titre were observed, especially for proviral load (rho = -0.387, P < 0.05). These results suggest that HTLV-1 proviral load and antibody titre influence the S. stercoralis load via disturbance of the host immunity, and that proviral load would be an especially useful predictive marker of the risk of development of strongyloidiasis in patients infected with both S. stercoralis and HTLV-1.

Risk factors for HTLV-I and II in individuals attending a clinic for sexually transmitted diseases.

BACKGROUND: To date, few studies have provided information on risk factors for human t-lymphotropic viruses (HTLV) types I and II in European countries. In particular, few data are available from published studies conducted in STD centers. GOALS: To identify risk factors for HTLV-I and HTLV-II infection and to better distinguish the epidemiologic patterns of the two viruses in Italy. STUDY DESIGN: A cross-sectional study of individuals at high risk of sexually or parenterally transmitted infections attending a large STD center in an urban setting was conducted. Serologic tests for HTLV-I and II, HIV, hepatitis virus type B (HBV), hepatitis virus type C (HCV), and syphilis were performed. Information regarding at-risk behavior was collected using a specific questionnaire. RESULTS: From January 1994 to June 1996, 1,457 individuals were recruited; of them, 1,016 (69.7%) were males, 1,051 (72.4%) Italians, and 288 (19.8%) non-Europeans. One thousand seventy-five (74.8%) participants were noninjecting-drug-using heterosexuals, 285 (19.6%) were men who have sex with men, and 97 (6.6%) were injecting drug users (IDU). The mean age of the study participants was 33.6 (+/-10.5) years. Nine (0.6%) individuals were positive for HTLV-I antibodies and 9 (0.6%) for HTLV-II antibodies. The prevalence of HTLV-I among IDUs, men who have sex with men, and noninjecting-drug-using heterosexuals, was 2.1% (2/97), 1.4% (4/ 285), and 0.3% (3/1085), respectively. HTLV-II prevalence was 8.2% (8/97) among IDUs and 0.09% (1/1075) among noninjecting-drug-using heterosexuals. Among the nine HTLV-II-positive individuals, eight were Italian IDUs and one was a noninjecting-drug-using heterosexual man from India. None of the 285 men who have sex with men had HTLV-II antibodies. HTLV-infected individuals tended to be older than those who were uninfected. HTLV-I-infected individuals were more likely to be non-European and to have antibodies against Treponema pallidum. Injecting drug use tended to be independently associated with HTLV-II infection. CONCLUSIONS: The data suggest a role of sexual behavior in the spread of HTLV-I, which is more likely to be detected in individuals coming from endemic areas. Injecting drug use remains the most important risk factor for HTLV-II infection in Italy.

HTLV-I infection in squirrel monkeys (Saïmiri sciureus) using autologous, homologous, or heterologous HTLV-I-transformed cell lines.

Peripheral blood mononuclear cells (PBMC) from three adult male squirrel monkeys (Saïmiri sciureus) were transformed by human T-cell leukemia/lymphoma virus type I (HTLV-I) by cocultivation with lethally irradiated human MT-2 cells. Three permanent monkey T-cell lines producing HTLV-I were obtained and characterized. Six weeks after inoculation seroconversion was observed in three of three monkeys inoculated with autologous transformed T cells and in two of three monkeys receiving homologous cells. Proviral DNA was detected in their PBMC at various times after inoculation, with the highest proviral load and antibody titers being found in monkeys infected with homologous cells. Monkeys inoculated with heterologous MT-2 cells did not seroconvert, and HTLV-I provirus was detected only transiently in their PBMC. To determine whether in vitro and in vivo HTLV-I infection of squirrel monkey cells led to a selection of monkey-adapted viral mutants, comparative sequencing of the proviral gp21 env between ex vivo monkey HTLV-I-infected PBMC, the inoculum, and MT-2 cells was done and no significant differences were detected. The squirrel monkey, which is naturally free of simian T-cell leukemia/ lymphoma virus, thus appears to be a suitable model for evaluating HTLV-I candidate vaccines and for studying the pathogenesis of HTLV-I.

Marked inhibition of the intracellular multiplication of Legionella pneumophila in monocytes isolated from carriers of human T lymphotrophic virus type I.

Intracellular growth patterns of Legionella pneumophila were examined in monocytes obtained from carriers of human T-lymphotropic virus type I (HTLV-1) and controls who were HTLV-1 seronegative. All subjects were seronegative for antibodies against L. pneumophila. Bacterial growth was determined 0, 1, 2, and/or 3 days after infecting peripheral blood mononuclear cells (PBMCs) with the bacteria. The intracellular growth of L. pneumophila was markedly inhibited in HTLV-1 carriers compared with normal controls. When the lymphocytes were depleted from the HTLV-1 carrier PBMC cultures before infection, this inhibition was abolished. Inhibition reappeared, however, when the 72-h culture supernatants of PBMCs from HTLV-1 carriers were added to the lymphocyte-depleted cultures. Culture supernatants of infected and uninfected PBMCs from HTLV-1 carriers exhibited markedly increased levels of interferon-gamma (IFN-gamma) and tumor necrosis factor alpha (TNF-alpha) compared with the HTLV-1 seronegative controls. In the HTLV-1 carriers, IFN-gamma was produced by the CD4+ lymphocytes, whereas TNF-alpha was secreted by the monocytes. Addition of anti-IFN-gamma or anti-TNF-alpha antibodies to the HTLV-1 carrier PBMC cultures diminished the inhibition of intracellular growth of L. pneumophila. Results suggest that the monocytes are activated in HTLV-1 carriers. These findings may explain why an opportunistic infection by certain intracellular pathogens is rarely seen among HTLV-1 carriers.

Constitutive expression of various chemokine genes in human T-cell lines infected with human T-cell leukemia virus type 1: role of the viral transactivator Tax.

We examined the genetic expression of 2 CXC chemokines (IL-8, IP-10), 5 CC chemokines (MCP-1, MIP-lalpha, MIP-1beta, RANTES, 1309) and 1 C chemokine (SCM-1/lymphotactin/ATAC) in various human T-cell lines. By Northern blot analysis, HTLV-1-positive T-cell lines were found to express a number of chemokine genes at variable levels and in different combinations. However, none of the chemokine genes was expressed in HTLV-1-negative T-cell lines. We further confirmed secretion of 3 chemokines (IL-8, MIP-1alpha and RANTES) by some HTLV-1-positive T-cell lines. To examine the role of the HTLV-1-encoded transactivator Tax in the induction of these chemokine genes, we used JPX-9 and JPX-M, which were stably transformed with tax and non-functional tax, respectively, under the control of a metallothionein promoter. Induction of tax in JPX-9 with Cd2+ was accompanied by rapid induction of IL-8, IP-10, MIP-1alpha, MIP-1beta, 1309 and SCM-1 as determined by reverse transcription PCR. No such induction was seen in JPX-M. We thus suggest that Tax is, at least in part, responsible for constitutive expression of certain chemokine genes in HTLV-1-infected T cells. Aberrant production of various chemokines by HTLV-1- infected T cells may impact on the pathophysiology of HTLV-1-associated diseases.

Dependency of antibody titer on provirus load in human T lymphotropic virus type I carriers: an interpretation for the minor population of seronegative carriers.

To evaluate the prevalence of seronegative carriers of human T lymphotropic virus type I (HTLV-I), buffy coat samples from 1015 Okinawan high school students were tested by immunoassays and nested polymerase chain reaction (PCR). Among 17 HTLV-I carriers, 1 person who was seronegative and 1 who was PCR-negative were identified. gag and tax/rex PCR titers correlated with each other (r = .92; P < .001). Of the 17 carriers, 14 (82%) had high virus loads (geometric averages, 522 gag and 703 tax/rex copies/micrograms of DNA; 95% confidence intervals, 38-7260 and 75-6594, respectively). Carriers with low virus loads had < or = 2.2 gag copies. In the high-virus-load group, the gag PCR titers correlated with the antibody titers (r = 0.88; P < .001). The regression line intersected the minimum antibody detection level at 35 gag copies/micrograms of DNA. These results suggest that a small percentage of carriers may be seronegative.

Virions released from cells transfected with a molecular clone of human T-cell leukemia virus type I give rise to primary and secondary infections of T cells.

The ability of molecular clones of human T-cell leukemia virus type I (HTLV-I) to direct the synthesis of infectious virions has not previously been demonstrated. An HTLV-I provirus originating from an adult T-cell leukemia patient was cloned into a plasmid vector and is designated pCS-HTLV. This molecular clone was shown to direct the synthesis of viral mRNA and proteins in transiently transfected cells; in addition, virus structural proteins were released into the culture medium. Viral proteins were assembled into virions that sedimented at a buoyant density characteristic of retrovirus particles and whose morphology was verified by electron microscopy. Virions concentrated from transiently transfected cell supernatants were incubated with primary cord blood lymphocytes or with transformed T-cell lines to establish that these particles were infectious. Expression of spliced, viral mRNAs in the T-cell cultures after both primary and secondary infections with cell-free virus revealed that pCS-HTLV encodes an infectious provirus.

Virus production and spontaneous cell proliferation in HTLV-I-infected lymphocytes.

Cultured peripheral blood lymphocytes (PBL) from HTLV-I-infected individuals proliferate in the absence of added mitogens and/or cytokines. In an attempt to answer questions regarding the activating signals for cells and virus, antibodies that react with cell surface components that are known to regulate cell activation and antibodies reacting with viral proteins were added to cultures of PBL from HTLV-I-infected, disease-free individuals. Spontaneous proliferation and virus production increased in the presence of antibodies reacting with CD3 and alpha/beta T cell receptors (TCR) while antibodies to HLA class II and viral proteins had no effect. Addition of HLA class I antibodies shut down virus production and cell proliferation. These observations indicate that both virus and cell activation may occur through the alpha/beta TCR on the infected cell. Cyclosporin A, however, markedly decreased cell proliferation but had only a modest suppressive effect on virus production. Thus, the uncoupling of cell proliferation from virus production by cyclosporin A suggests the possibility that the signal transduction pathways for these two events are different.

Primate T-lymphotropic virus type I LTR sequence variation and its phylogenetic analysis: compatibility with an African origin of PTLV-I.

Due to the low evolutionary rate and the limited horizontal transmission of human T-lymphotrophic virus type I (HTLV-I), its phylogenetic analysis reveals the movements and contacts of ancient populations. Since simian strains cannot be distinguished from human strains by phylogenetic criteria, this virus has appropriately been called primate T-lymphotropic virus type I (PTLV-I). We sequenced the LTR of six PTLV-I strains: three HTLV-I strains from African patients with tropical spastic paraparesis (TSP) (Equateur, Zaire), two laboratory HTLV-I strains of Japanese origin, MT-2 and MT-4, and one STLV-I from a baboon of the primate center in Sukhumi, Georgia. We applied four phylogenetic inference methods: neighbor-joining (NJ), unweighted pair group method using arithmetic averages (UPGMA), Fitch and Wagner parsimony (pars), and maximum likelihood (ML), to these 6 LTR sequences and 18 published LTR sequences (cosmopolitan, African, and Melanesian HTLV-I strains and African and Asian STLV-I strains). Three major HTLV-I subtypes can be identified with all four methods: the cosmopolitan HTLV-Ia, the central African HTLV-Ib, clearly descendant from a STLV-I CH-like African ancestral simian strain, and the Melanesian HTLV-Ic, probably descendant from an Asian STLV-I strain. We observe a segregation of PTLV-I sequences according to their geographical origin and not according to host species. The Zairean strains form a cluster closely related to an STLV-I strain isolated from a chimpanzee (STLV-I CH) and distinct from western African strains, which belong to the cosmopolitan subtype of HTLV-I. The Sukhumi STLV-I strain found in a captive-born baboon was of Asian descent. We experienced rooting problems with UPGMA when using HTLV-II as an outgroup. Concordant results with all four methods were obtained by eliminating HTLV-II LTR sequence fragments with bad alignment to HTLV-I. This resulted in a HTLV-II root node on the African STLV-I TAN90 terminal branch (with bootstrap values above 92% for the NJ and pars methods) and not on the Asian STLV-I PtM3 branch, as has been derived by others based on their use of UPGMA. The results of the analyses also support a higher evolutionary rate of PTLV-I in Asia, implying that the trees obtained with the NJ and ML methods have a higher reliability. These results are more compatible with an ancient African origin of PTLV-I than with an Asian origin.

Regional specificity of HTLV-I proviral integration in the human genome.

The location of HTLV-I (human T-cell leukemia virus type 1) proviral sequences in the genome of infected human cells was explored by hybridization of a viral probe with compositional fractions of host-cell DNAs. In the twelve cases examined, HTLV-I sequences were absent from the GC-poorest 40% of the host genome (namely, from isochores that are below 39% GC). Transcriptionally inactive proviral sequences were localized in GC-poor isochores (comprised between 39% and 42-44% GC) of the human genome, which are characterized by a constant and low gene concentration. In contrast, transcriptionally active proviral sequences were found in the GC-rich and very GC-rich isochores, which are gene rich, transcriptionally and recombinationally active, and endowed with an open chromatin structure. Since GC-rich isochores are present in R'-bands and very GC-rich isochores form T-bands, these results also provide information on the location of HTLV-I proviral sequences in human chromosomes. The results obtained with HTLV-I are in agreement with the non-random, compartmentalized integration of animal retroviral sequences that had been previously observed in other viral-host systems. They provide, however, much more detailed information on the regional location of proviral sequences in the host genome and on the correlation between their transcription and their location.