Tropical Spastic Paraparesis Research Articles

Neurofilament Light in CSF and Plasma Is a Marker of Neuronal Damage in HTLV-1-Associated Myelopathy and Correlates With Neuroinflammation.

Background and ObjectivesTo evaluate the usefulness of CSF and plasma neurofilament light (Nf-L) as a biomarker for human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM).MethodsNf-L, CXCL10, and neopterin were measured by ELISA in 83 CSF samples obtained from 49 individuals living with HTLV-1/2. Plasma Nf-L was also measured by single molecule array. Results were correlated with duration of disease, age, mobility, CSF cell counts, CSF protein, and HTLV-1 proviral load.ResultsNf-L was detected in all CSF samples (median [range] = 575 [791.8–2,349] pg/mL) and positively correlated with markers of inflammation (CXCL10 (r = 0.733), neopterin (r = 0.499), cell count (r = 0.403), and protein levels (r = 0.693) in CSF; p < 0.0015). There was an inverse correlation between Nf-L and duration of disease (r = −0.584, p < 0.0001). Wheelchair-dependent patients had high concentrations of markers of inflammation and neuronal damage. Concentrations of CXCL10, neopterin, and Nf-L remained elevated in follow-up samples (mean follow-up 5.2 years). Nf-L in plasma correlated with concentration of Nf-L, neopterin, CXCL10, and protein in CSF.ConclusionsNf-L in plasma and CSF has potential to be used as a biomarker of disease activity in HAM. Neuronal damage seems to be more intense early in disease but persists long term. Wheelchair-dependent patients have ongoing neuroinflammation.

Development, Validation, and Internal Consistency of the Positive Psychology-Based Acceptance of Illness Scale (PAIS): A Culturally-Appropriate Japanese Measure

Acceptance of illness has been shown to improve the well-being of individuals suffering from chronic illnesses. We developed a new acceptance of illness scale, “Positive Psychology-Based Acceptance of Illness Scale: PAIS,” for HTLV-1 associated myelopathy (HAM) patients, one of the intractable neurological diseases with a chronic course. The validity and internal consistency of this PAIS were examined in 260 HAM patients in Japan. Exploratory factor analysis extracted four factors with 21 items: “Loving myself as I am”; “Experiencing the grace of illness”; “Feeling a loving connection with others”; and “Developing as a mature person”. Cronbach’s α was .83 to .88, except for Factor 4 which was slightly low at 0.64, and internal consistency was confirmed. A significant correlation was found between the PAIS and the index of convergent validity. The study’s findings are an important step toward a more comprehensive concept of acceptance of illness.

Germinal epimutation of Fragile Histidine Triad (FHIT) gene is associated with progression to acute and chronic adult T-cell leukemia diseases

BackgroundHuman T cell Leukemia virus type 1 (HTLV-I) is etiologically linked to adult T cell leukemia/lymphoma (ATL) and an inflammatory neurodegenerative disease called HTLV-I-associated myelopathy or tropical spastic paraparesis (HAM/TSP). The exact genetic or epigenetic events and/or environmental factors that influence the development of ATL, or HAM/TSP diseases are largely unknown. The tumor suppressor gene, Fragile Histidine Triad Diadenosine Triphosphatase (FHIT), is frequently lost in cancer through epigenetic modifications and/or deletion. FHIT is a tumor suppressor acting as genome caretaker by regulating cellular DNA repair. Indeed, FHIT loss leads to replicative stress and accumulation of double DNA strand breaks. Therefore, loss of FHIT expression plays a key role in cellular transformation.MethodsHere, we studied over 400 samples from HTLV-I-infected individuals with ATL, TSP/HAM, or asymptomatic carriers (AC) for FHIT loss and expression. We examined the epigenetic status of FHIT through methylation specific PCR and bisulfite sequencing; and correlated these results to FHIT expression in patient samples.ResultsWe found that epigenetic alteration of FHIT is specifically found in chronic and acute ATL but is absent in asymptomatic HTLV-I carriers and TSP/HAM patients’ samples. Furthermore, the extent of FHIT methylation in ATL patients was quantitatively comparable in virus-infected and virus non-infected cells. We also found that longitudinal HTLV-I carriers that progressed to smoldering ATL and descendants of ATL patients harbor FHIT methylation.ConclusionsThese results suggest that germinal epigenetic mutation of FHIT represents a preexisting mark predisposing to the development of ATL diseases. These findings have important clinical implications as patients with acute ATL are rarely cured. Our study suggests an alternative strategy to the current “wait and see approach” in that early screening of HTLV-I-infected individuals for germinal epimutation of FHIT and early treatment may offer significant clinical benefits.

Evaluation of iron, ferritin, copper, and ceruloplasmin along with proviral load in human T lymphotropic virus type 1-associated myelopathy.

Human T-cell lymphotropic virus type 1 (HTLV-1) infection can cause HTLV-I-associated myelopathy (HAM). In this study, we evaluated the levels of serum iron, ferritin, copper, and ceruloplasmin, and their correlations with HTLV-1 proviral load (PVL) and standard indices of HAM severity. In total, 114 subjects were recruited in this cross sectional study in Qaem Hospital, Mashhad, Iran between 2017 and 2018, including 36 HAM and 32 asymptomatic cases (ACs) and 46 healthy people (HSs). The clinical examination and evaluation of serum levels of biochemical factors and proviral load were performed. The PVL in HAM and ACs were 1835.49±382.81 and 280.97±67.41 copies/104 PBMCs, which statistically differed. Significant differences were also observed in plasma levels of iron, copper, and ceruloplasmin, among the three groups, while ferritin level was not considerably different. For HAM severity, the mean Osame motor disability scale (OMDS) and overactive bladder-validated-8-questionnaire (OABV-8) scores were 4.97±0.38 and 15.75±0.83, respectively, that had no significant correlations with the biochemical variables. Even though the studied elements in HAM group did not affect the severity of the disease, the levels of copper and ceruloplasmin might be determinants of the development and progression of HAM, as they are shown to play role in progression of other neurological diseases.

Modeling and analysis of a within-host HIV/HTLV-I co-infection.

Human immunodeficiency virus (HIV) and human T-lymphotropic virus type I (HTLV-I) are two retroviruses that attack the {text {CD4}}^{+}T cells and impair their functions. Both HIV and HTLV-I can be transmitted between individuals through direct contact with certain body fluids from infected individuals. Therefore, a person can be co-infected with both viruses. HIV causes acquired immunodeficiency syndrome (AIDS), while HTLV-I is the causative agent for adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Several mathematical models have been developed in the literature to describe the within-host dynamics of HIV and HTLV-I mono-infections. However, modeling a within-host dynamics of HIV/HTLV-I co-infection has not been involved. The present paper is concerned with the formulation and investigation of a new HIV/HTLV-I co-infection model under the effect of Cytotoxic T lymphocytes (CTLs) immune response. The model describes the interaction between susceptible {text {CD4}}^{+}T cells, silent HIV-infected cells, active HIV-infected cells, silent HTLV-infected cells, Tax-expressing HTLV-infected cells, free HIV particles, HIV-specific CTLs and HTLV-specific CTLs. The HIV can spread by virus-to-cell transmission. On the other side, HTLV-I has two modes of transmission, (i) horizontal transmission via direct cell-to-cell contact through the virological synapse, and (ii) vertical transmission through the mitotic division of Tax-expressing HTLV-infected cells. The well-posedness of the model is established by showing that the solutions of the model are nonnegative and bounded. We define a set of threshold parameters which govern the existence and stability of all equilibria of the model. We explore the global asymptotic stability of all equilibria by utilizing Lyapunov function and Lyapunov–LaSalle asymptotic stability theorem. We have presented numerical simulations to justify the applicability and effectiveness of the theoretical results. In addition, we evaluate the effect of HTLV-I infection on the HIV dynamics and vice versa.

A significant association between CXCL10 -1447 A > G and IL18 -607 C > A gene polymorphism with human T-cell lymphotropic virus type 1 associated myelopathy/tropical spastic paraparesis (HAM-TSP), a case-control report from city of Mashhad, Iran.

Human T-cell lymphotropic virus type 1 (HTLV-1) is the first isolated retrovirus from humans, and 2-3% of infected individuals suffer from HTLV-1 associated myelopathy tropical spastic paraparesis (HAM-TSP). Previous studies indicated that the risk of HAM-TSP could be correlated with the individuals' genetic alterations. Mashhad is one of the areas infected with HTLV-1 in Iran. This study designed to examine the association between several important gene polymorphisms and HAM-TSP. Genotypes of 232 samples from controls, HTLV-1 carriers, and HAM-TSP patients were examined for FAS-670 (A > G), CXCL10-1447 (A > G), Foxp3-3279 (C > A), IL-18 -137 (C > G), and IL-18 -607 (C > A) gene polymorphisms by different polymerase chain reaction (PCR) techniques. A non-significant association was observed between FAS-670 A > G, Foxp3-3279 C > A, and IL-18 -137 C > G gene polymorphisms and HAM-TSP. Nevertheless, a significant (P<0.001) association between CXCL10-1447 A > G and IL-18 -607 C > A gene polymorphisms with HAM-TSP was observed in our study population. As previous studies revealed that the CXCL10 level in the cerebrospinal fluid of HAM-TSP patients was associated with the disease progression, and as we noticed, a direct association was observed between CXCL10-1447 A > G polymorphism and HAM-TSP. These polymorphisms might be recommended as a valuable prediction criterion for the severity of the disease. The contradiction between our findings and other studies regarding IL-18 -607 C > A gene polymorphism might be associated with various factors such as genotypes frequency in diverse races and population heterogeneity in the city of Mashhad.

Screening for Human T-Cell Lymphotropic Virus (HTLV) in Pregnant Women in the Peruvian Amazon and Systematic Review with Meta-Analysis of HTLV Infection in Peru.

Background. Human T-cell lymphotropic virus type 1 (HTLV-1) is responsible for tropical spastic paraparesis and HTLV-1-associated leukemia/lymphoma. The infection is endemic in some areas of Peru, but its prevalence in the Peruvian Amazon is not well established. We aimed to assess the seroprevalence of HTLV-1 infection in pregnant women in the Peruvian Amazon. Moreover, we performed a systematic literature review and meta-analysis of the seroprevalence of HTLV infection in Peru. (2) Methods. This is a prospective cross-sectional study involving pregnant women attending health centers in the city of Iquitos, Peru, in May and June 2019. The presence of antibodies against HTLV-1 was assessed using ELISA (HTLV I + II ELISA recombinant v.4.0, Wiener lab, Rosario, Argentina). Positive cases were confirmed by Western Blot and HTLV-1 proviral load. (3) Results. The study included 300 pregnant women with a mean age of 26 years (standard deviation [SD] 6.4). Five patients were diagnosed with HTLV-1 infection (prevalence 1.7%, 95% confidence interval (CI) 0.7% to 3.8%). Pregnant women with HTLV-1 infection were discretely younger (mean age 22.6 [SD 22.6] vs. 26.8 [SD 6.3]; p = 0.128). None of the five women had been transfused, and all were asymptomatic. Two (40%) also had a positive serology for Strongyloides, but larvae were not detected in any of the parasitological stool studies. The systematic review component identified 40 studies, which showed that the prevalence of HTLV infection in the general population was 2.9% (95% CI 1.2% to 5.3%) and in women of childbearing age, 2.5% (95% CI 1.2% to 4.0%). (4) Conclusion. The prevalence of HTLV-1 in the Peruvian Amazon basin is about 1.7%, indicating an endemic presence. Screening for HTLV-1 in prenatal care is warranted.

Spirituality as Strategies for Coping With Tropical Spastic Paraparesis: Results of Focus Group.

In the logic of integrality in health, one of the aspects less addressed by assistance services is the question of spirituality. This study utilized qualitative analysis from focus groups to identify whether spirituality can contribute to coping with problems arising from the HTLV-1 myelopathy associated or tropical spastic paraparesis (HAM/TSP). The testimonies were recorded and then transcribed. The information was then systematized by the analysis of thematic-categorical content. When giving voice to people who suffer from HAM/TSP, there is clear evidence that spirituality, understood broadly and not restricted to institutionalized religious practices, is expressed in narratives of feeling for others and trust in God. Through spiritual solutions, people with HAM/TSP find the strength to face their disability and pain.

HTLV on the government agenda: the case of the states of Bahia and Minas Gerais, Brazil

HTLV is a retrovirus that affects the human T-lymphocytes. Transmission is bloodborne, sexual, or mother-to-child. Most infected persons are asymptomatic carriers, but some may develop severe cases such as tropical spastic paraparesis, leukemia/lymphoma, and other manifestations. Brazil is considered the country with the highest absolute number of cases, with an estimated 800,000 infected individuals. This article aimed to investigate and analyze the process of inclusion of HTLV on the government agenda in the states of Bahia and Minas Gerais, and which impacted health sector actions and policies. Interviews were held with key actors, and a document search was performed for analysis, using as the main reference the Multiple Streams framework proposed by John Kingdon. Various factors contributed to the theme's inclusion on the health sector agenda in Bahia, the state of Brazil with the widest range of policies on HTLV, involving high prevalence of the infection, a favorable political context, and activism by infected individuals. In Minas Gerais, we observed difficulties in the implementation of this health sector policy; due to the lack of organized advocacy groups, the problem was not a priority in the state's Health Departments. In the current context, individuals with HTLV infection and other stakeholders still have a long road ahead with social mobilization for investments in the area, drafting and implementation of public policies, and guarantee of social rights.

Therapeutic effects of virtual reality video gaming on functional mobility, balance, and gait speed in individuals with tropical spastic paraparesis: A randomized crossover clinical trial

INTRODUCTION: Individuals with human T-cell lymphotropic virus 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) experience sensorimotor alterations, which can affect functional performance. Virtual reality (VR) videogaming is a therapeutic option, though there is scarce evidence for its use in this population. We aimed to investigate the therapeutic effects of a VR video game on functional mobility, balance, and gait speed in individuals with HAM/TSP. METHODS: We conducted a blinded, crossover clinical trial comprising 29 individuals with HAM/TSP and randomized them into two groups: (1) early therapy: rehabilitative protocol started immediately after the initial evaluation and (2) late therapy: rehabilitative protocol started 10 weeks later. We assessed all participants for balance using the Berg Balance Scale (BBS) scores, functional mobility using the Timed Up and Go (TUG) test, and gait speed using video camera and CvMob software. Differences were considered significant if p<0.05. RESULTS: The early therapy group individuals presented with higher BBS scores (p=0.415), less TUG times (p=0.290), and greater gait speed (p=0.296) than the late therapy group individuals. CONCLUSIONS: VR videogaming is a useful option for rehabilitative therapy in individuals with HAM/TSP; it positively affects balance, functional mobility, and gait speed.

Co-expression of HBZ, TAX and FOXp3 and HTLV-1-associated myelopathy/ tropical spastic paraparesis development in HTLV-1-infected individuals: A systematic review

Human T-cell lymphotropic virus type 1 (HTLV-1) is associated with the development of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). It has been reported that the HTLV-1 proteins (specifically TAX and HBZ) can modulate FOXp3, resulting in an immune imbalance that can favor the progression of HAM/TSP. This review aims to summarize the literature in order to clarify the relationship between the expression of HTLV-1 mRNAs and/or viral proteins (TAX and HBZ) with the expression of mRNA and/or protein FOXp3 and their correlation with HAM/ TSP development. This systematic review was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. The search strategy was performed on the Medical Literature Analysis and Retrieval System Online and Latin American and Caribbean Literature in Health Sciences Platform using subject descriptors. After screening, six articles were included in this review. The studies suggested that TAX and HBZ have a directly proportional correlation with FOXp3 in individuals with HAM/TSP, which also presented an increased expression of FOXp3 compared to asymptomatic controls and/or healthy donors. This systematic review indicates that TAX and HBZ can interact with FOXp3 and that interaction may influence HAM/ TSP development.

1707. Clinical Profile of Human T-Lymphotropic Virus Type I Infection in Pediatric Population in a Referral Hospital in Colombia

BackgroundThe Human T-lymphotropic virus type 1 (HTLV-1), affects around ten to twenty million people worldwide, predominantly in intertropical regions (Africa, Japan, Melanesia, Australia, and South America Pacific Coast). The most common disorders associated are T-cell leukemia/lymphoma (ALT) and HTLV-1-associated myelopathy (HAM). Studies have reported other clinical manifestations in HTLV-1, still studies are needed in pediatric population to improve diagnosis and treatment of infected patients.MethodsDescriptive, retrospective cohort study, conducted in our referral pediatric hospital in Cali, Colombia. Included pediatric patients (1 to 18 years of age) diagnosed with HTLV-1 infection, between January 2017 to March 2020.ResultsTwelve patients were included, seven males and five females. Eleven patients were from and resided in the Colombian Pacific coast. Ten patients showed nutritional deficiencies.None showed clinical or laboratory signs of ALT, neither neurological symptoms or physical exam suggesting HAM. In terms of associated diseases and opportunistic infections, none had a positive HIV ELISA test, and stool tests were all negative for Strongiloydes. Four presented infective dermatitis, and two showed lesions suggesting scabies.Eight patients presented respiratory symptoms with chest CT scans showing signs of chronic inflammation, bronchiectasis, and subpleural bullae as the major findings. Additional tests were carried out in bronchoalveolar fluid, four had positive galactomannan test,suggesting pulmonary aspergillosis, two exhibited positive gene PCR testing for Mycobacterium tuberculosis.Regarding inflammatory diseases, one patient presented with symptoms of Inflammatory Bowl Disease, with biopsy confirming Crohn’s disease. Another patient presente abrupt vision loss, diagnosed with Vogt Koyanagi Hadara Syndrome after ophthalmological evaluation.Summary features HTLV-1 patients Ground-glass opacity diffusely distributed in both lungs with multiple bronchiectasis involving predominantly lung bases. Cystic images diffusely distributed in both lungs, some subpleural and other centrilobular. ConclusionIt is important to consider alternative manifestations of HTLV-1 infection in the pediatric population, including pulmonary disease, opportunistic co-infections, and inflammatory disorders. It is crucial to diagnose this disease in childhood to reach a better control of this neglected infection that affects predominantly vulnerable population in low-income countries.Disclosures All Authors: No reported disclosures

Implications of human T-lymphotropic virus in pregnancy: A case report and a review of the diagnostic criteria and management proposal.

Human T-lymphotropic virus (HTLV) is considered to be the most highly oncogenic existing virus, being the cause of several fatal diseases such as adult T cell leukemia-lymphoma (ATL) and HTLV-I-associated myelopathy (HAM). The main transmission methods are unprotected sexual intercourse, vertical transmission and breastfeeding and direct exposure to infected blood or tissue. The identification of infected mothers prior to delivery is a highly important step in preventing mother to child transmission. Universal antenatal screening for HTLV is not recommended in Romania, although there are sufficient data demonstrating the risk of vertical transmission. We present the case of an HTLV-1-infected pregnant woman, with an aim to highlight: i) points of strategy for the management of HTLV during pregnancy; ii) the particularities of the course of pregnancy; and iii) the aspects that show the importance of knowing the status regarding the HTLV infection antepartum. The case was particular due to the ascendant proviral load during the pregnancy period, which led to the initiation of antiretroviral therapy and the particular pregnancy outcome with preterm rupture of membranes and fetal growth restriction. According to current recommendations, pregnant women infected with HTLV-1 should be advised to refrain from donating blood, body organs, or other tissues. There is no evidence of the number of individuals infected with this virus in Romania at present, and the diagnosis can only occur by chance. A specific treatment or immunization for HTLV infection does not currently exist, thus preventive methods are the only tool to reduce the prevalence and mortality of this infection.

Impact of Human T-Cell Lymphotropic Virus Infection on Survival Following Stem Cell Transplantation

Human T-Cell Lymphotropic Virus (HTLV) Types 1 or 2 are delta retroviruses that may lead to complications including adult T-cell leukemia-lymphoma (ATLL) and HTLV-1-associated myelopathy (HAM). There is concern that immunosuppression may result in progression from an asymptomatic carrier state to ATLL or HAM. Data on the safety of stem cell transplantation (SCT) in patients with HTLV-1/2 infection are lacking. The Center for International Blood and Marrow Transplant Research (CIBMTR) was queried for all patients who tested positive for HTLV infection in the pre-transplantation workup and underwent either autologous SCT (AutoSCT) or allogeneic SCT (AlloSCT) between 2008-2017. The primary outcome was overall survival up to four years post-SCT, assessed using the Kaplan-Meier statistic. All analyses were univariate and did not adjust for differences in disease, disease stage or patients characteristics. In those who underwent AutoSCT, 54 (0.5%) patients were HTLV-positive and 9,837 were HTLV-negative. In those who underwent AlloSCT, 126 (0.7%) patients were HTLV-positive and 18,084 were HTLV-negative. In the HTLV-negative group, a larger proportion underwent AlloSCT for acute myeloid leukemia in the HTLV-negative group, while Non-Hodgkin lymphoma/other leukemia was more common in the HTLV-positive group (P&amp;lt;0.001). Additional patient demographics are listed in Table 1. No difference in overall survival (p=0.661) or non-relapse mortality (p=0.522) was noted following AutoSCT based on HTLV status. Following AlloSCT, univariate analysis showed the HTLV-positive patients had a statistically significant lower overall survival (Figure 1; p=0.013) and higher non-relapse mortality at year four (Figure 2; p=0.023). In conclusion, survival after AutoSCT seems unaffected by HTLV status. While the underlying indications for AlloSCT differed in HTLV-infected patients, decreased overall survival and increased non-relapse mortality were seen in HTLV-positive patients. Reasons for increased non-relapse mortality may include increased infectious complications or graft-versus-host disease. Further studies are needed to understand the relative contributions of these factors. Disclosures Janakiram: Takeda, Fate, Nektar: Research Funding. Sloan:Stemline: Consultancy; Abbvie: Consultancy.

Degenerative Cervical Myelopathy: Pathophysiology and Current Treatment Strategies.

Chronic compression or ischemia of the spinal cord in the cervical spine causes a clinical syndrome known as cervical myelopathy. Recently, a new term “degenerative cervical myelopathy (DCM)” was introduced. DCM encompasses spondylosis, intervertebral disk herniation, facet arthrosis, ligamentous hypertrophy, calcification, and ossification. The pathophysiology of DCM includes structural and functional abnormalities of the spinal cord caused by static and dynamic factors. In nonoperative patients, cervical myelopathy has a poor prognosis. Surgical treatments, such as anterior or posterior decompression accompanying arthrodesis, arthroplasty, or laminoplasty, should be considered for patients with chronic progressive cervical myelopathy. Surgical decompression can prevent the progression of myelopathy and improve the neurologic status, functional outcomes, and quality of life, irrespective of differences in medical systems and sociocultural determinants of health. The anterior surgical approach to the cervical spine has the advantage of removing or floating the intervertebral disk, osteophytes, and ossification of the posterior longitudinal ligament that compress the spinal cord directly. The posterior surgical approach to the cervical spine is mainly used for multisegment spinal cord compression in patients with cervical lordosis. In this review article, we addressed the pathophysiology, clinical manifestations, differential diagnosis, and treatment options for DCM.

Spasticity distribution and severity in individuals with HTLV-1-associated myelopathy/tropical spastic paraparesis.

In individuals with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP), spasticity is one of the main symptoms. The neurological signs of the disease are well defined, but details of how spasticity appears in these individuals have not been well explored. To describe spasticity location and severity of HAM/TSP individuals. Cross-sectional study with individuals older than 18 years, diagnosed with HAM/TSP and with lower limb spasticity. Pregnant women, individuals with other associated neurological diseases, and those using antispastic drugs were not included. Spasticity was assessed by the Modified Ashworth Scale (MAS), applied to the abductor, adductor, flexor, and extensor muscles of the hips, flexors, and extensors of the knees, dorsiflexors, plantiflexors, evertors, and inverters of the foot. Thirty participants were included. The plantiflexor muscles (90%), knee extensors (80%), knee flexors (63,3%), and adductors (50%) were most frequently affected by spasticity. Twenty-three (76.7%) individuals had mixed spasticity, 5 (16.7%) with distal spasticity and 2 (6.7%) with proximal spasticity. MAS was similar between the lower limbs in at least 6 of the 10 muscle groups of each individual. Spasticity was mostly mixed in the lower limbs, with more frequently mild severity. The individuals were partially symmetrical between the lower limbs. The most affected muscle groups were the plantiflexors, knee extensors and flexors and the hip adductors, consecutively, being predominantly symmetrical.

Regulation of Expression and Latency in BLV and HTLV.

Human T-lymphotrophic virus type 1 (HTLV-1) and Bovine leukemia virus (BLV) belong to the Deltaretrovirus genus. HTLV-1 is the etiologic agent of the highly aggressive and currently incurable cancer adult T-cell leukemia (ATL) and a neurological disease HTLV-1-associated myelopathy (HAM)/tropical spastic paraparesis (TSP). BLV causes neoplastic proliferation of B cells in cattle: enzootic bovine leucosis (EBL). Despite the severity of these conditions, infection by HTLV-1 and BLV appear in most cases clinically asymptomatic. These viruses can undergo latency in their hosts. The silencing of proviral gene expression and maintenance of latency are central for the establishment of persistent infection, as well as for pathogenesis in vivo. In this review, we will present the mechanisms that control proviral activation and retroviral latency in deltaretroviruses, in comparison with other exogenous retroviruses. The 5′ long terminal repeats (5′-LTRs) play a main role in controlling viral gene expression. While the regulation of transcription initiation is a major mechanism of silencing, we discuss topics that include (i) the epigenetic control of the provirus, (ii) the cis-elements present in the LTR, (iii) enhancers with cell-type specific regulatory functions, (iv) the role of virally-encoded transactivator proteins, (v) the role of repressors in transcription and silencing, (vi) the effect of hormonal signaling, (vii) implications of LTR variability on transcription and latency, and (viii) the regulatory role of non-coding RNAs. Finally, we discuss how a better understanding of these mechanisms may allow for the development of more effective treatments against Deltaretroviruses.

Cognitive impairment in the HTLV-1 infection: a comparative study associated with functional performance.

Human T cell leukemia virus type-I (HTLV-1) infection courses with a myelopathy, the tropical spastic paraparesis (HAM/TSP). In a case-control study, we compared the neuropsychological profile and functional characteristics in two case HTLV-1-infected groups (asymptomatic and with HAM/TSP) with a control group negative for HTLV-1. Subjects were paired for age, sex, and educational features. The case group differed from control group in neuropsychological measures such as in episodic memory recall, executive functions, and fine motor dexterity measure. Individuals with HAM/TSP have more depressive symptoms and worst performance in activities of daily living (ADL) presenting a less functionality. In multivariate models, the fine motor performance, the executive functioning, the recognition memory, and the depressive symptoms explained part of the variance in functionality. Those findings may contribute to understand of everyday life impairments and limitations of HTLV-1-infected population and to organize the rehabilitation. Once more, based in neuropsychological and functional data, we can reaffirm that HTLV-1 is never a benign condition, but sometimes it is only in a stage coursing with less symptoms.

Limitations in daily activities, risk awareness, social participation, and pain in patients with HTLV-1 using the SALSA and Participation scales

BackgroundTropical spastic paraparesis or HTLV-associated myelopathy (TSP/HAM) may prevent, limit or restrict the performance of daily living activities, and as a consequence, several aspects of life are affected. ObjectiveThe aim of this study was to evaluate activity limitations, risk awareness, social participation, quality of life, and pain in individuals infected with HTLV-1. MethodsThis was an observational, descriptive, analytical, cross-sectional study with a quantitative approach. An interview questionnaire, the Screening of Activity Limitation and Safety Awareness (SALSA) scale, the Participation scale, a quality of life questionnaire (SF-36) and the Brief Pain Inventory were used. ResultsA total of 55 patients with HTLV-1 were interviewed (62% asymptomatic and 38% symptomatic). In both groups, there was a higher frequency of patients aged 41–50 years old (35.3% asymptomatic and 38.1% symptomatic), with complete secondary education (47.1% asymptomatic and 42.9% symptomatic), and married (64.7% asymptomatic and 52.4% symptomatic). Of the symptomatic patients, 33.3% were retired; among asymptomatic patients, 20.6% performed domestic activities. The majority of patients in both groups had not received blood transfusions. Sexual intercourse was still practiced by patients. After assessment, asymptomatic patients had no activity limitations (64.7%), and symptomatic patients presented limitations (90.5%). None of the groups showed good risk awareness. There was no restriction on social participation in 97.1% of asymptomatic patients and in 52.4% among symptomatics. Both groups complained of pain, being more frequent in the lumbar spine in asymptomatic patients and in the knees in symptomatic patients. Pain was more severe in symptomatic patients and affected aspects of quality of life. ConclusionThe clinical follow-up instruments must be adopted by healthcare professionals to monitor new symptoms so as to avoid the onset of limitations identified in symptomatic patients, in addition to enabling continuous surveillance of asymptomatic patients.

A novel positive feedback-loop between the HTLV-1 oncoprotein Tax and NF-\u03baB activity in T-cells

BackgroundHuman T-cell leukemia virus type 1 (HTLV-1) infects primarily CD4+ T-lymphocytes and evoques severe diseases, predominantly Adult T-Cell Leukemia/ Lymphoma (ATL/L) and HTLV-1-associated Myelopathy/ Tropical Spastic Paraparesis (HAM/TSP). The viral transactivator of the pX region (Tax) is important for initiating malignant transformation, and deregulation of the major signaling pathway nuclear factor of kappa B (NF-κB) by Tax represents a hallmark of HTLV-1 driven cancer.ResultsHere we found that Tax mutants which are defective in NF-κB signaling showed diminished protein expression levels compared to Tax wildtype in T-cells, whereas Tax transcript levels were comparable. Strikingly, constant activation of NF-κB signaling by the constitutive active mutant of inhibitor of kappa B kinase (IKK2, IKK-β), IKK2-EE, rescued protein expression of the NF-κB defective Tax mutants M22 and K1-10R and even increased protein levels of Tax wildtype in various T-cell lines while Tax transcript levels were only slightly affected. Using several Tax expression constructs, an increase of Tax protein occurred independent of Tax transcripts and independent of the promoter used. Further, Tax and M22 protein expression were strongly enhanced by 12-O-Tetradecanoylphorbol-13-Acetate [TPA; Phorbol 12-myristate 13-acetate (PMA)]/ ionomycin, inducers of NF-κB and cytokine signaling, but not by tumor necrosis factor alpha (TNF-α). On the other hand, co-expression of Tax with a dominant negative inhibitor of κB, IκBα-DN, or specific inhibition of IKK2 by the compound ACHP, led to a vast decrease in Tax protein levels to some extent independent of Tax transcripts in transiently transfected and Tax-transformed T-cells. Cycloheximide chase experiments revealed that co-expression of IKK2-EE prolongs the half-life of M22, and constant repression of NF-κB signaling by IκBα-DN strongly reduces protein stability of Tax wildtype suggesting that NF-κB activity is required for Tax protein stability. Finally, protein expression of Tax and M22 could be recovered by NH4Cl and PYR-41, inhibitors of the lysosome and the ubiquitin-activating enzyme E1, respectively.ConclusionsTogether, these findings suggest that Tax’s capability to induce NF-κB is critical for protein expression and stabilization of Tax itself. Overall, identification of this novel positive feedback loop between Tax and NF-κB in T-cells improves our understanding of Tax-driven transformation.