The relative contributions of infectious and mitotic spread to HTLV-1 persistence.

Human T-lymphotropic virus type-1 (HTLV-1) persists within hosts via infectious spread (de novo infection) and mitotic spread (infected cell proliferation), creating a population structure of multiple clones (infected cell populations with identical genomic proviral integration sites). The relative contributions of infectious and mitotic spread to HTLV-1 persistence are unknown, and will determine the efficacy of different approaches to treatment. The prevailing view is that infectious spread is negligible in HTLV-1 persistence beyond early infection. However, in light of recent high-throughput data on the abundance of HTLV-1 clones, and recent estimates of HTLV-1 clonal diversity that are substantially higher than previously thought (typically between 104 and 105 HTLV-1+ T cell clones in the body of an asymptomatic carrier or patient with HTLV-1-associated myelopathy/tropical spastic paraparesis), ongoing infectious spread during chronic infection remains possible. We estimate the ratio of infectious to mitotic spread using a hybrid model of deterministic and stochastic processes, fitted to previously published HTLV-1 clonal diversity estimates. We investigate the robustness of our estimates using three alternative estimators. We find that, contrary to previous belief, infectious spread persists during chronic infection, even after HTLV-1 proviral load has reached its set point, and we estimate that between 100 and 200 new HTLV-1 clones are created and killed every day. We find broad agreement between all estimators. The risk of HTLV-1-associated malignancy and inflammatory disease is strongly correlated with proviral load, which in turn is correlated with the number of HTLV-1-infected clones, which are created by de novo infection. Our results therefore imply that suppression of de novo infection may reduce the risk of malignant transformation.

HTLV-I induces lesions in the pulmonary system: A systematic review.

This study analyzed the relationship between infection by human T-cell lymphotropic virus type 1 (HTLV-1) and changes in the pulmonary system. Cohort and case-control study models that analyzed a causal association between HTLV-1 and changes in the pulmonary system were considered. There were no restrictions on language and publication period. The study was registered in the PROSPERO systematic analysis database (Protocol No. CRD42017078236) and was prepared according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The following databases were used: PubMed, BVS Regional Portal, Embase, CINAHL and Web of Science. We utilized the Newcastle-Ottawa Scale to assess the methodological quality of published studies and the Kappa coefficient to assess the agreement level between two reviewers. Of the total 1156 studies retrieved by the search strategy, 28 were considered potentially eligible (Kappa test = 0.928). Of the 28 studies, three fully met the inclusion criteria. These indicated that pulmonary lesions, such as bronchiectasis and bronchitis/bronchiolitis, were observed in patients with HTLV-1, with high-resolution computed tomography of the chest being the main method of diagnostic investigation. The analyzed cohort and case-control studies indicated an etiological relationship between HTLV-1 infection and the presence of lung lesions, with emphasis on bronchiectasis in the presence of high viral loads, as well as a higher mortality in these individuals compared with the general population.

Acupuncture in the treatment of HTLV-I-associated myelopathy / tropical spastic Paraparesis.

We investigate the possible effects of acupuncture on the improvement of neurological problems in HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP)disease. Twenty patients with HAM/TSP were studied in this pre and post-test clinical trial. Urinary incontinence, global motor disability, spasticity, and pain severity were evaluated before, one month, and three-month after the intervention. Analyses demonstrated a significant reduction of urinary symptoms one month after acupuncture (P = 0.023). A significant improvement was observed in patients' pain and the spasticity at the upper extremity joints, one and three-month after the intervention (P < 0.05). This study suggests that body acupuncture can be used as a complementary treatment to improve HAM/TSP neurological symptoms.

HTLV-1 bZIP factor: the key viral gene for pathogenesis.

Human T cell leukemia virus type 1 (HTLV-1) causes adult T-cell leukemia-lymphoma (ATL) and inflammatory diseases. The HTLV-1 bZIP factor (HBZ) gene is constantly expressed in HTLV-1 infected cells and ATL cells. HBZ protein suppresses transcription of the tax gene through blocking the LTR recruitment of not only ATF/CREB factors but also CBP/p300. HBZ promotes transcription of Foxp3, CCR4, and T-cell immunoreceptor with Ig and ITIM domains (TIGIT). Thus, HBZ is critical for the immunophenotype of infected cells and ATL cells. HBZ also functions in its RNA form. HBZ RNA suppresses apoptosis and promotes proliferation of T cells. Since HBZ RNA is not recognized by cytotoxic T cells, HTLV-1 has a clever strategy for avoiding immune detection. HBZ plays central roles in maintaining infected T cells in vivo and determining their immunophenotype.

Ocular vestibular evoked myogenic potential (VEMP) reveals mesencephalic HTLV-1-associated neurological disease.

PURPOSE: Vestibular Myogenic Evoked Potential (VEMP) evaluates vestibulo-ocular and vestibulo-collic reflexes involved in the function of the otolithic organs and their afferent pathways. We compared the results of cervical and ocular VEMP in HTLV-1 associated myelopathy (HAM) and HTLV-1-asymptomatic infection. PARTICIPANTS AND METHODS: This cross-sectional study included 52 HTLV-1-infected individuals (26 HAM and 26 asymptomatic carriers) and 26 seronegative controls. The groups were similar regarding age and gender. Participants underwent simultaneous ocular and cervical VEMP. The stimulus to generate VEMP was a low-frequency tone burst sound tone burst, with an intensity of 120 decibels normalized hearing level, bandpass filter from 10 to 1,500 Hertz (Hz), with 100 stimuli at 500 Hz and 50 milliseconds recording time. The latencies of the electrophysiological waves P13 and N23 for cervical VEMP and N10 and P15 waves for ocular VEMP were compared among the groups. The absence or delay of the electrophysiological waves were considered abnormal results. RESULTS: Ocular VEMP was similar among the groups for N10 (p = 0.375) and different for P15 (p≤0.001). Cervical VEMP was different for P13 (p = 0.001) and N23 (p = 0.003). About ocular VEMP, in the HTLV-1-asymptomatic group, normal waves were found in 23(88.5%) individuals; in HAM group, normal waves were found in 7(26.9%). About cervical VEMP, 18(69.2%) asymptomatic carriers presented normal waves and only 3(11.5%) patients with HAM presented normal waves. Abnormalities in both VEMPs were found in 1(3.8%) asymptomatic carrier and in 16(61.5%) patients with HAM. CONCLUSION: Neurological impairment in HAM was not restricted to the spinal cord. The mesencephalic connections, tested by ocular VEMP, have been also altered. Damage of the oculomotor system, responsible for eye stabilization during head and body movements, may explain why dizziness is such a frequent complaint in HAM.

Prevalence of Bowel Symptoms in Patients Infected with Human T-Lymphotropic type 1 Virus.

INTRODUCTION: Bowel dysfunction is frequent in patients with spinal cord diseases, but little is known about the prevalence of bowel symptoms in human T-lymphotropic virus-(HTLV-1) infected individuals. The purpose of this study is to determine the frequency of bowel symptoms in HTLV-1 infected individuals and their correlation with the degree of neurologic disease. METHODS: This is a cross-sectional study comparing the frequency of bowel symptoms in HTLV-1-infected individuals* and seronegative donors (controls). Patients answered a questionnaire, the Rome III Criteria was applied, and stool consistency was evaluated by the Bristol Stool Form Scale. The individuals were classified as HTLV-1 carriers, probable HTLV-1 myelopathy and definitive HTLV-1 associated myelopathy or tropical spastic paraparesis (definitive HAM / TSP)**. RESULTS: We studied 72 HTLV-1 infected individuals and 72 controls with equal age and gender distribution. Constipation was the most frequent complaint, occurring in 38 % of HTLV-1 individuals and in 15 % of the controls. In comparison to the seronegative controls, the probability of constipation occurrence was approximately 18 times higher in definitive HAM / TSP patients. Straining, lumpy or hard stools, sensation of anorectal obstruction/blockage, fewer than 3 defecations per week, flatulence, soiling, evacuation pain, and bleeding were also more frequent in the HTLV-1 patients than in the controls. Moreover, bowel symptoms were more frequent in patients with definitive or probable HAM / TSP than in carriers. CONCLUSIONS: Bowel symptoms were more frequent in HTLV-1-infected patients than in seronegative controls and the frequency of bowel symptoms correlated with the severity of neurologic disease.

Balance Impairments in Patients with Human T-Cell Lymphotropic Virus Type 1 Infection.

The human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus from the Retroviridae family that infects cluster of differentiation 4 (CD4) T-lymphocytes and stimulates their proliferation. A severe consequence of this infection can be the HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), which is associated with a progressive demyelinating disease of the upper motor neurons. The HAM/TSP conditions frequently present with neurological complaints such as gait impairment, sphincter disturbances, and several sensory losses. We compared findings from the posturographic evaluation from the asymptomatic HTLV-1 infected subjects, HTLV-1 infected subjects having HAM/TSP, and control group database. A force plate was used to record the postural oscillations. Analysis of variance and multivariate linear discriminant analysis were used to compare the data obtained from the three groups of participants. In general, HAM/TSP patients had worse postural balance control than did the HTLV-1 patients and the controls (p < 0.05). We found that in six out of ten parameters of the postural balance control, there was a gradual increase in impairment from control to HTLV-1 to HAM/TSP groups. All parameters had higher values with the subject's eyes closed. The multivariate linear discriminant analysis showed there was a reasonable difference in results between the control and HAM/TSP groups, and the HTLV-1 group was at the intersecting area between them. We found that HAM/TSP patients had worse balance control than did HTLV-1 infected patients and the control group, but asymptomatic HTLV-1 infected patients represent an intermediate balance control status between controls and HAM/TSP patients. Posturographic parameters can be relied on to identify subtle changes in the balance of HTLV-1 patients and to monitor their functional loss. HTLV-1 is a tropical disease that can be transmitted by sexual intercourse, blood transfusion, and breast-feeding. Some infected subjects develop an HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a condition characterized by spasticity, weakness in lower limbs, and difficulty in walking long distances and going up and down the stairs, besides the history of falls. We compared the body oscillations using a force plate to investigate the postural balance control. HTLV-1 infected patients had imbalance that could be identified by posturographic parameters. Patients with HAM/TSP clearly had balance impairments, while HTLV-1 without HAM/TSP had a subtle impairment that was not seen on clinical scales, suggesting that these patients were in the middle between healthy and HAM/TSP patients, and carried a risk of developing severe imbalance postural control. We suggest that more research should be done with the aim to identify the subtle signs in asymptomatic HTLV-1 patients to investigate if this group of patients need attention similar to the HAM/TSP patients.

Memory impairment: an intermediate clinical syndrome symptom in HTLV-1-infected patients?

BACKGROUND: Although classical human T-cell lymphocyte virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis syndrome is the most frequent HTLV-1-associated neurological disorder, some "minor" neurological disorders can be seen in "asymptomatic" carriers. These disorders, including cognitive alterations already described in clinical cases and studies, may constitute an intermediate syndrome (IMS) between the asymptomatic state and myelopathy. The aim of this study was to investigate the presence of cognitive deficits in patients with HTLV-1 virus, who usually are diagnosed as asymptomatic. METHODS: A total of 54 HTLV-1-infected patients were evaluated, 35 asymptomatic and 19 with minor neurological alterations (evaluated by a neurologist); 25 HTLV-1-seronegative individuals served as controls. The instruments used were: Beck's Depression Inventory, Lawton's Daily Life Activity Scale, and a complete neuropsychological battery. The application of these evaluation instruments was performed blindly, with the evaluator neuropsychologist not knowing the clinical condition of the patient. RESULTS: Most of the participants in this cohort, including seronegative controls, were female (n = 57, 72.21%), their mean age was 52.34 years (SD = 14.29) and their average schooling was 9.70 years (SD = 4.11). DISCUSSION: Participants classified with IMS had lower gross scores when compared with both the patients classified as asymptomatic and with the control group, and when tested for auditory episodic memory of immediate (p < 0.01), and late (p = 0.01), recall. CONCLUSION: Patients with IMS presented with memory impairment when compared with asymptomatic patients and seronegative individuals; this is one of the symptoms that aids in the classification of the syndrome.

Association between human T cell leukemia virus 1 (HTLV-1) infection and advanced periodontitis in relation to hematopoietic activity among elderly participants: a cross-sectional study.

BACKGROUND: We reported that human T cell leukemia virus 1 (HTLV-1) infection is positively associated with atherosclerosis. Recent evidence has revealed a close association of periodontitis with atherosclerosis, endothelial dysfunction, and disruption of the microcirculation. However, the association between HTLV-1 and advanced periodontitis has not been investigated to date. Since hematopoietic activity is closely linked to endothelial maintenance activity and is known to decline with age, we hypothesized that the state of hematopoietic activity influenced the association between HTLV-1 and advanced periodontitis in elderly participants. METHODS: A cross-sectional study was performed including 822 elderly participants aged 60-99 years who participated in a dental health check-up. Advanced periodontitis was defined as a periodontal pocket ≥ 6.0 mm. Participants were classified as having low or high hematopoietic activity according to the median values of reticulocytes. RESULTS: HTLV-1 infection was positively related to advanced periodontitis among participants with lower hematopoietic activity (lower reticulocyte count), but not among participants with higher hematopoietic activity (higher reticulocyte count). The adjusted odds ratio (95% confidence interval) considering potential confounding factors was 1.92 (1.05-3.49) for participants with a lower reticulocyte count and 0.69 (0.35-1.36) for participants with a higher reticulocyte count. CONCLUSIONS: Among elderly participants, the association between HTLV-1 infection and advanced periodontitis is influenced by hematopoietic activity. Since hematopoietic activity is associated with endothelial maintenance, these findings provide an efficient tool for clarifying the underlying mechanism of the progression of periodontitis among elderly participants.

Memory impairment: an intermediate clinical syndrome symptom in HTLV-1-infected patients? / Comprometimento da memória: um sintoma de síndrome clínica intermediária em pacientes infectados pelo HTLV-1?

Background Although classical human T-cell lymphocyte virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis syndrome is the most frequent HTLV-1-associated neurological disorder, some "minor" neurological disorders can be seen in "asymptomatic" carriers. These disorders, including cognitive alterations already described in clinical cases and studies, may constitute an intermediate syndrome (IMS) between the asymptomatic state and myelopathy. The aim of this study was to investigate the presence of cognitive deficits in patients with HTLV-1 virus, who usually are diagnosed as asymptomatic. Methods A total of 54 HTLV-1-infected patients were evaluated, 35 asymptomatic and 19 with minor neurological alterations (evaluated by a neurologist); 25 HTLV-1-seronegative individuals served as controls. The instruments used were: Beck's Depression Inventory, Lawton's Daily Life Activity Scale, and a complete neuropsychological battery. The application of these evaluation instruments was performed blindly, with the evaluator neuropsychologist not knowing the clinical condition of the patient. Results Most of the participants in this cohort, including seronegative controls, were female (n = 57, 72.21%), their mean age was 52.34 years (SD = 14.29) and their average schooling was 9.70 years (SD = 4.11). Discussion Participants classified with IMS had lower gross scores when compared with both the patients classified as asymptomatic and with the control group, and when tested for auditory episodic memory of immediate (p < 0.01), and late (p = 0.01), recall. Conclusion Patients with IMS presented with memory impairment when compared with asymptomatic patients and seronegative individuals; this is one of the symptoms that aids in the classification of the syndrome.

RESUMO Apesar da síndrome de HAM / TSP clássica ser a perturbação neurológica mais atribuída, alguns distúrbios neurológicos denominados "menores" são vistos em portadores "assintomáticos" de HTLV-1. Esses distúrbios, incluindo alterações cognitivas já observadas em descrições de casos clínicos e estudos, podendo constituir uma verdadeira síndrome clínica intermediária (SI) entre o estado assintomático e mielopatia. O objetivo deste estudo foi investigar a presença de déficits cognitivos em pacientes portadores do vírus HTLV-1 diagnosticados classicamente como assintomáticos. Métodos Foram avaliadas 54 pessoas, sendo 35 assintomáticos, 19 com alterações neurológicas menores (avaliados por um neurologista) e 25 HTLV-1 negativo. Os instrumentos utilizados foram: Inventário Beck de Depressão, Escala de Atividades de Vida Diária de Lawton e uma completa bateria neuropsicológica. A aplicação destes instrumentos de avaliação foi realizada de forma cega, ou seja, a avaliadora não sabia a condição clinica do paciente. Resultados A maioria dos participantes era do sexo feminino (n = 57, 72,21%), com idade média de 52.34 anos (DP = 14,29) e escolaridade média de 9.70 anos (DP = 4,11). Discussão Avaliando o desempenho cognitivo nos três grupos, foi possível observar que os participantes classificados com SI, apresentaram menores escores brutos, quando comparados, com os pacientes com classificação assintomática e grupo controle e, em relação à memória episódica auditiva de evocação imediata (p < 0,01) (p = 0,01) e tardia. Conclusão Diante dos resultados foi possível concluir que os pacientes com SI apresentam comprometimento de memória quando comparado com os outros grupos, sendo possível, ser este um dos sintomas para auxiliar na classificação da síndrome.

HIV co-infection in HTLV-1 carriers in Spain.

BACKGROUND: Human retroviruses HIV and HTLV share transmission routes. HIV widely spread in Spain during the 80 s through injection drug use and sex, and nowadays HIV rates in Spain account for one of the largest in Europe. In contrast, HTLV-1 is not endemic in Spain, despite hosting huge numbers of migrants from highly endemic regions. Herein, we report the rate and main features of the HIV-HTLV co-infected population in Spain. METHODS: A national registry exists in Spain for HTLV since year 1989. Data from standardized case report forms and one centralized lab repository were reviewed, especially for the subset with HTLV-HIV co-infection. RESULTS: Up to December 2018, a total of 369 individuals with HTLV-1 had been diagnosed in Spain. 64% of the population were females, and Latin American individuals accounted for 64.5%. Classical HTLV-associated illnesses were found in 12.7% (myelopathy) and 7.6% (leukemia). HIV coinfection was found in 12 (3.2%). Of those, 3 patients (25%) were female and 39 (75%) were of non-Spanish origin. All but two harbored HIV-1 subtype B, being non-B variants found in the two West Africans. Exposure had been sexual in most cases, being 4 homosexual men. Seven HTLV-HIV co-infected patients had developed AIDS and two had developed myelopathy. There was no evidence for increased HTLV-1 clinical pathogenicity due to HIV coinfection. CONCLUSION: HIV coinfection is infrequent (<5%) among HTLV-1 carriers in Spain. More than half of co-infected patients come from Latin America. Sexual contact is the most frequent risk behavior, being MSM one third of cases. Late diagnosis explains the high rate (9/12) of clinical manifestations in our HIV-HTLV co-infected population.

HTLV-1 Tax-1 interacts with SNX27 to regulate cellular localization of the HTLV-1 receptor molecule, GLUT1.

An estimated 10-20 million people worldwide are infected with human T cell leukemia virus type 1 (HTLV-1), with endemic areas of infection in Japan, Australia, the Caribbean, and Africa. HTLV-1 is the causative agent of adult T cell leukemia (ATL) and HTLV-1 associated myopathy/tropic spastic paraparesis (HAM/TSP). HTLV-1 expresses several regulatory and accessory genes that function at different stages of the virus life cycle. The regulatory gene Tax-1 is required for efficient virus replication, as it drives transcription of viral gene products, and has also been demonstrated to play a key role in the pathogenesis of the virus. Several studies have identified a PDZ binding motif (PBM) at the carboxyl terminus of Tax-1 and demonstrated the importance of this domain for HTLV-1 induced cellular transformation. Using a mass spectrometry-based proteomics approach we identified sorting nexin 27 (SNX27) as a novel interacting partner of Tax-1. Further, we demonstrated that their interaction is mediated by the Tax-1 PBM and SNX27 PDZ domains. SNX27 has been shown to promote the plasma membrane localization of glucose transport 1 (GLUT1), one of the receptor molecules of the HTLV-1 virus, and the receptor molecule required for HTLV-1 fusion and entry. We postulated that Tax-1 alters GLUT1 localization via its interaction with SNX27. We demonstrate that over expression of Tax-1 in cells causes a reduction of GLUT1 on the plasma membrane. Furthermore, we show that knockdown of SNX27 results in increased virion release and decreased HTLV-1 infectivity. Collectively, we demonstrate the first known mechanism by which HTLV-1 regulates a receptor molecule post-infection.

Different roles of CXCR1 and CXCR2 in HTLV-1 carriers and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) patients.

One of the prominent features of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is the excessive recruitment of leukocytes to the central nervous system (CNS), which leads to an inflammatory response-with chemokines and their receptors playing the main role in this recruitment. The aim of the study was to examine the relation of CXCR1 and CXCR2, both of which are involved in the trafficking of lymphocytes into the CNS, with the outcome of HTLV-1 infection. The mRNA levels of CXCR1 and CXCR2 were examined in peripheral blood mononuclear cells (PBMCs) of HAM/TSP patients, HTLV-1 asymptomatic carriers (ACs), and healthy controls (HCs). Furthermore, the frequency of CD4+ and CD8+ T cells expressing CXCR1 and CXCR2 was evaluated in the studied groups. The results of the present study showed a substantial increase in the mean mRNA expression of CXCR2 in the HAM/TSP patients compared to the HCs and ACs (p < 0.001). A positive correlation was also found between PVL and CXCR2 mRNA expression in the total population of HTLV-1-infected subjects (R = 0.526, p < 0.001). Moreover, the percentage of CD8+ CXCR2-expressing cells was higher in HAM/TSP patients compared to ACs and HCs (p < 0.05, p < 0.01, respectively). Although the percentage of CD4+ CXCR2-expressing cells was higher in HAM/TSP patients than in ACs and HCs, a significant difference was only found between HAM/TSP patients and HCs (p < 0.05). No significant difference in the CXCR1 mRNA expression was observed in the studied groups. The frequency of the CD8+ CXCR1- and CD4+ CXCR1-expressing cells was significantly lower in HAM/TSP patients than in ACs and HCs (p < 0.001 and p < 0.01, respectively). In conclusion, the high frequency of CXCR2 CD8+ T cells and the high levels of CXCR2 mRNA expression in HAM/TSP patients are associated with disease pathogenesis, while the high frequencies of CXCR1 T cells in ACs might suggest that these cells act as effector CD8 T cells and are involved in controlling the viral spread and modulation of the immune response.

Prevalence of bowel symptoms in patients infected with human T-lymphotropic type 1 virus

Abstract INTRODUCTION: Bowel dysfunction is frequent in patients with spinal cord diseases, but little is known about the prevalence of bowel symptoms in human T-lymphotropic virus-(HTLV-1) infected individuals. The purpose of this study is to determine the frequency of bowel symptoms in HTLV-1 infected individuals and their correlation with the degree of neurologic disease. METHODS: This is a cross-sectional study comparing the frequency of bowel symptoms in HTLV-1-infected individuals* and seronegative donors (controls). Patients answered a questionnaire, the Rome III Criteria was applied, and stool consistency was evaluated by the Bristol Stool Form Scale. The individuals were classified as HTLV-1 carriers, probable HTLV-1 myelopathy and definitive HTLV-1 associated myelopathy or tropical spastic paraparesis (definitive HAM / TSP)**. RESULTS: We studied 72 HTLV-1 infected individuals and 72 controls with equal age and gender distribution. Constipation was the most frequent complaint, occurring in 38 % of HTLV-1 individuals and in 15 % of the controls. In comparison to the seronegative controls, the probability of constipation occurrence was approximately 18 times higher in definitive HAM / TSP patients. Straining, lumpy or hard stools, sensation of anorectal obstruction/blockage, fewer than 3 defecations per week, flatulence, soiling, evacuation pain, and bleeding were also more frequent in the HTLV-1 patients than in the controls. Moreover, bowel symptoms were more frequent in patients with definitive or probable HAM / TSP than in carriers. CONCLUSIONS: Bowel symptoms were more frequent in HTLV-1-infected patients than in seronegative controls and the frequency of bowel symptoms correlated with the severity of neurologic disease.

Stability of the HTLV-1 glycoprotein 46 (gp46) gene in an endemic region of the Brazilian Amazon and the presence of a significant mutation (N93D) in symptomatic patients.

BACKGROUND: The human T-lymphotropic virus type 1 (HTLV-1) affects 2-5 million people worldwide, and is associated with a number of degenerative and infectious diseases. The Envelope glycoproteins (gp) are highly conserved among the different HTLV-1 isolates, although nucleotide substitutions in the region that codifies these proteins may influence both the infectivity and the replication of the virus. The gp46 gene has functional domains which have been associated with the inhibition of the formation of the syncytium, cell-cell transmission, and the production of antibodies. The present study investigated the genetic stability of the gp46 gene of HTLV-1 in an endemic region of Brazilian Amazonia. METHODS: Index case (IC - a sample of a given family group) carriers of HTLV-1 were investigated in the metropolitan region of Belém (Pará, Brazil) between January 2010 (registered retrospectively) and December 2015. The sequences that codify the gp46 were amplified by PCR, purified and sequenced (MF084788-MF084825). The gene was characterized using bioinformatics and Bayesian Inference. RESULTS: The 40 patients analyzed had a mean age of 45.2 years and 70% presented some type of symptom, with a predominance of pain and sensitivity, dysautonomia, and motor disorders. All patients presented the aA (Transcontinental Cosmopolitan) genotype, with an extremely low mutation rate, which is characteristic of the codifying region (aA - 1.83 × 10-4 mutations per site per year). The gp46 gene had a nucleotide diversity of between 0.00% and 2.0%. Amino acid mutations were present in 66.6% of the samples of individuals with signs/symptoms or diseases associated with HTLV-1 (p = 0.0091). Of the three most frequent mutations, the previously undescribed N93D mutant was invariably associated with symptomatic cases. CONCLUSIONS: The aA HTLV-1 subtype is predominant in the metropolitan region of Belém and presented a high degree of genetic stability in the codifying region. The rare N93D amino acid mutation may be associated with the clinical manifestations of this viral infection. IMPORTANCE: Little is known of the phylogeny of HTLV-1 in the endemic region of Brazilian Amazonia, and few complete gene sequences are available for the gp46 glycoprotein from the local population. The nucleotide sequences of the viral gp46 gene recorded in the present study confirmed the genetic stability of the region, and pointed to a homogeneous viral group, with local geographic characteristics. Further research will be necessary to more fully understand the molecular diversity of this protein, given the potential of this codifying region as a model for an effective HTLV-1 vaccine. The identification of a rare mutation (N93D), present only in symptomatic patients, should also be investigated further as a potential clinical marker. TRIAL REGISTRATION: ISRCTN 12345678, registered 28 September 2014.

CT Chest and pulmonary functional changes in patients with HTLV-associated myelopathy in the Eastern Brazilian Amazon.

The aim of this study was to compare computed tomography (CT) scans of chest and lung function among patients with Human T-Lymphotropic Virus Type 1 (HTLV) with and without HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP). In this cross-sectional study performed between January 2013 and June 2016, we included 48 patients with HAM/TSP (19 women and 11 men) and without HAM/TSP (12 women and 6 men). We compared CT findings and lung functions of these groups. Patients who had HAM/TSP had abnormal CT findings (P = 0.000), including more frequent bronchiectasis (P = 0.049), parenchymal bands (P = 0.007), interlobular septal thickening (P = 0.035), and pleural thickening (P = 0.009). In addition, neither patients with HAM/TSP (9/30; 30%) nor the controls (0/18; 0%) had obstructive or restrictive lung disease (P = 0.009). HTLV diagnosis should be considered in all patients with abnormal CT findings in whom no other cause is apparent. It is important to remember that lung disease increases the rates of morbidity and mortality in developing countries.

Treatment of rheumatoid arthritis with biologics may exacerbate HTLV-1-associated conditions: A case report.

RATIONALE: There are roughly 5 to 10 million persons infected with human T-lymphotropic virus type 1 (HTLV-1) worldwide, and the safety of treating this population with biologics remains poorly understood. PATIENT CONCERNS AND DIAGNOSIS: An HTLV-1-infected 66-year-old female with HTLV-1 uveitis (HU) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Her HU had been in remission and her HAM/TSP symptoms had been managed effectively with oral steroids for years. However, she developed severe rheumatoid arthritis (RA) after failing to respond well to conventional anti-rheumatic agents. INTERVENTIONS: She was administered two intravenous 8mg/kg doses of the biologic tocilizumab. OUTCOMES: Subsequently, her RA symptoms resolved, but she suffered a recurrence of HU and exacerbation of HAM/TSP symptoms. When she was switched back to steroid-based treatment, HU and HAM symptoms both improved, but RA symptoms again worsened. Finally, an attempt to substitute the biologic abatacept and reduce the steroids failed when HAM/TSP symptoms again became aggravated. LESSONS: To the best of our knowledge, this represents the first report worldwide of a biologic aggravating HTLV-1-associated conditions. This report suggests that caution is advised when using biologics to treat HTLV-1-infected patients, though further research is required to clarify the situation.

Quality of life and pain multidimensional aspects in individuals with HTLV-1.

HTLV-1 creates a chronic health condition that involves moderate to severe pain with a negative impact on quality of life (QoL). There is no consensus on which attitudes to pain are more related to the worsening of QoL in HTLV-1 infected patients. The aim of this study was to investigate the correlation between QoL and multidimensional aspects of pain in patients with HTLV-1. A cross-sectional study was conducted in Salvador, Bahia, Brazil. The study included individuals diagnosed with HTLV-1. The Short Form 36 Questionnaire was used to analyze QoL, and the Brief Pain Inventory was used to assess multidimensional aspects of pain. The mean pain intensity was 4.88±3.06 on the visual pain scale, and the average impact on QoL corresponded to a loss of approximately 40%. Moderate to high correlations between pain intensity and all domains of QoL were observed and compared reaction attitudes for general activity, mood, ability to walk, ability to work, relationships, sleep, and ability to enjoy life (r>0.40; p<0.05). Moderate correlations were found between all domains of QoL, pain intensity, and reactive attitudes to pain. The greatest pain intensity impacts involved difficulty to walk and to work, and interpersonal relationships in the emotional aspect of QoL.

Barefoot Plantar Pressure Indicates Progressive Neurological Damage in Patients with Human T-Cell Lymphotropic Virus Type 1 Infection.

BACKGROUND: The human T-Cell Lymphotropic Virus Type 1 (HTLV-1) is a retrovirus associated with neurological alterations; individuals with HTLV-1 infection may develop HTLV-1 associated myelopathy / tropical spastic paraparesis (HAM/TSP). Frequent neurological complaints include foot numbness and leg weakness. In this study, we compared the distribution of the body weight on different areas of the foot in HTLV-1 patients with HAM/TSP, asymptomatic HTLV-1 patients, and healthy individuals. METHODOLOGY: We studied 36 HTLV-1 infected patients, who were divided in two groups of 18 patients each based on whether or not they had been diagnosed with HAM/TSP, and 17 control subjects. The evaluation included an interview on the patient's clinical history and examinations of the patient's reflexes, foot skin tactile sensitivity, and risk of falling. The pressure distribution on different areas of the foot was measured with baropodometry, using a pressure platform, while the patients had their eyes open or closed. MAIN FINDINGS: The prevalence of neurological disturbances-altered reflexes and skin tactile sensitivity and increased risk of falling-was higher in HTLV-1 HAM/TSP patients than in HTLV-1 asymptomatic patients. The medium and maximum pressure values were higher in the forefoot than in the midfoot and hindfoot in both HTLV-1 groups. In addition, the pressure on the hindfoot was lower in HAM/TSP patients compared to control subjects. CONCLUSIONS: The neurological disturbances associated with HTLV-1 infection gradually worsened from HTLV-1 asymptomatic patients to HAM/TSP patients. Baropodometry is a valuable tool to establish the extent of neurological damage in patients suffering from HTLV-1 infection.