Epidemiological and molecular evidence of intrafamilial transmission through sexual and vertical routes in Bahia, the state with the highest prevalence of HTLV-1 in Brazil.

INTRODUCTION: Familial clustering of HTLV-1 and related diseases has been reported in Brazil. However, intrafamilial transmission of HTLV-1 based on molecular analysis has been studied only in a few communities of Japanese immigrants and African-Brazilians. OBJECTIVE: To investigate the familial clustering of HTLV-1 infection and to determine the likely routes of transmission through epidemiological and genetic analyzes. METHODS: Medical records of 1,759 HTLV-1+ patients from de the Center for HTLV in Salvador, Brazil, were evaluated to identify first-degree relatives previously tested for HTLV-1. Familial clustering was assumed if more than one member of the same family was HTLV-1+. LTR regions of HTLV-1 sequences were analyzed for the presence of intrafamilial polymorphisms. Family pedigrees were constructed and analyzed to infer the likely transmission routes of HTLV-1. RESULTS: In 154 patients at least one other family member had tested positive for HTLV-1 (a total of 182 first-degree relatives). Of the 91 couples (182 individuals), 51.6% were breastfed, and 67.4% reported never using a condom. Of the 42 mother-child pairs, 23.8% had a child aged 13 years or younger; all mothers reported breastfeeding their babies. Pedigrees of families with 4 or more members suggests that vertical transmission is a likely mode of transmission in three families. Three families may have had both vertical and sexual transmission routes for HTLV-1. The genetic signatures of the LTR region of 8 families revealed 3 families with evidence of vertical transmission, another 3 families (spouses) with sexual transmission, and one family with both transmission routes. HTLV-1 sequences belonged to Cosmopolitan subtype HTLV-1a Transcontinental subgroup A. CONCLUSION: Sexual and vertical transmission routes contribute to the intrafamilial spread of HTLV-1 in the state of Bahia.

HTLV-1 Proviral Load in Vaginal Fluid Correlates with Levels in Peripheral Blood Mononuclear Cells.

BACKGROUND: The prevalence of human T-lymphotropic virus type-1 (HTLV-1) infection is higher in women, and sexual intercourse has been described as an important route of male-to-female transmission. The present study aimed to quantify HTLV-1 proviral load (PVL) in vaginal fluid, and to investigate correlations with PVL in peripheral blood mononuclear cells (PBMCs). In addition, cytopathological alterations and vaginal microbiota were evaluated. METHODS: HTLV-1-infected women were consecutively recruited at a multidisciplinary center for HTLV patients in Salvador, Brazil. All women underwent gynecological examinations to obtain cervicovaginal fluid and venipuncture for blood collection. PVL, as measured by real-time quantitative polymerase chain reaction (RT-qPCR), was expressed as the number of copies of HTLV-1/106 cells in blood and vaginal fluid samples. Light microscopy was used to assess cervicovaginal cytopathology and vaginal microbiota. RESULTS: In the 56 included women (43 asymptomatic carriers and 13 diagnosed with HTLV-1-associated myelopathy/tropical spastic paraparesis-HAM/TSP), mean age was 35.9 (SD ± 7.2) years. PVL was higher in PBMCs (median: 23,264 copies/106 cells; IQR: 6776-60,036) than in vaginal fluid (451.9 copies/106 cells; IQR: 0-2490) (p < 0.0001). PVL in PBMCs was observed to correlate directly with PVL in vaginal fluid (R = 0.37, p = 0.006). PVL was detected in the vaginal fluid of 24 of 43 (55.8%) asymptomatic women compared to 12 of 13 (92.3%) HAM/TSP patients, p = 0.02. Cytopathologic analyses revealed no differences between women with detectable or undetectable PVL. CONCLUSION: HTLV-1 proviral load is detectable in vaginal fluid and correlates directly with proviral load in peripheral blood. This finding suggests that sexual transmission of HTLV-1 from females to males may occur, as well as vertical transmission, particularly in the context of vaginal delivery.

Impaired flexibility in patients with tropical spastic paraparesis/HTLV-associated myelopathy: evaluation via pendulum fleximeter.

BACKGROUND: Flexibility is crucial to the harmonious execution of joint movements. While skeletal muscle dysfunction in patients with HTLV-1 can interfere with mobility, it is unclear whether these patients experience reduced flexibility. OBJECTIVE: To evaluate the differences in flexibility between HTLV-1-infected individuals with and without myelopathy compared with uninfected controls. We also investigated whether age, sex, body mass index (BMI), physical activity level, or lower back pain influence flexibility in HTLV-1-infected individuals. METHODS: The sample consisted of 56 adults, of which 15 did not have HTLV-1, 15 had HTLV-1 without myelopathy, and 26 had TSP/HAM. Their flexibility was assessed using the sit-and-reach test and a pendulum fleximeter. RESULTS: No differences in flexibility were observed between the groups with and without myelopathy and controls without HTLV-1 infection using the sit-and-reach test. The pendulum fleximeter results of individuals with TSP/HAM presented the lowest flexibility among the groups with respect to trunk flexion, hip flexion and extension, knee flexion, and ankle dorsiflexion, even after adjusting for age, sex, BMI, level of physical activity, and lower back pain using multiple linear regression models. Additionally, HTLV-1-infected individuals without myelopathy demonstrated reduced flexibility in movements: knee flexion, dorsiflexion, and ankle plantar flexion. CONCLUSIONS: Individuals with TSP/HAM demonstrated reduced flexibility in most of the movements evaluated by the pendulum fleximeter. Additionally, HTLV-1-infected individuals without myelopathy demonstrated reduced knee and ankle flexibility, potentially representing a marker of myelopathic development.

ANTECEDENTES: A flexibilidade é fundamental para a execução harmoniosa dos movimentos articulares. Embora a disfunção do músculo esquelético em pacientes com HTLV-1 possa interferir na mobilidade, não está claro se esses pacientes apresentam flexibilidade reduzida. OBJETIVO: Avaliar as diferenças de flexibilidade entre os indivíduos infectados com e sem mielopatia e o grupo controle sem infecção HTLV-1. Também investigamos se idade, sexo, índice de massa corporal (IMC), nível de atividade física ou dor lombar influenciam a flexibilidade em indivíduos infectados pelo HTLV-1. MéTODOS: A amostra foi composta por 56 adultos, dos quais 15 não possuíam HTLV-1, 15 possuíam HTLV-1 sem mielopatia e 26 possuíam TSP/HAM. A flexibilidade foi avaliada por meio do teste de sentar e alcançar e do flexímetro de pêndulo. RESULTADOS: Não foram observadas diferenças na flexibilidade entre os grupos com e sem mielopatia no teste de sentar e alcançar. Os resultados do flexímetro pendular dos indivíduos com TSP/HAM apresentaram a menor flexibilidade entre os grupos em relação à flexão do tronco, flexão e extensão do quadril, flexão do joelho e dorsiflexão do tornozelo, mesmo após ajuste para idade, sexo, IMC, nível de atividade física e dor lombar usando modelos de regressão múltipla linear. Além disso, os indivíduos infectados pelo HTLV-1 sem mielopatia demonstraram redução da flexibilidade nos movimentos de flexão do joelho, dorsiflexão e flexão plantar do tornozelo. CONCLUSãO: Indivíduos com TSP/HAM demonstraram redução da flexibilidade na maioria dos movimentos avaliados pelo flexímetro pendular. Além disso, indivíduos infectados pelo HTLV-1 sem mielopatia demonstraram redução da flexibilidade do joelho e tornozelo, representando potencialmente um marcador de desenvolvimento mielopático.

Impaired flexibility in patients with tropical spastic paraparesis/HTLV-associated myelopathy: evaluation via pendulum fleximeter / Flexibilidade prejudicada em pacientes com paraparesia espástica tropical/mielopatia associada ao HTLV: avaliação via flexímetro pendular

Abstract Background Flexibility is crucial to the harmonious execution of joint movements. While skeletal muscle dysfunction in patients with HTLV-1 can interfere with mobility, it is unclear whether these patients experience reduced flexibility. Objective To evaluate the differences in flexibility between HTLV-1-infected individuals with and without myelopathy compared with uninfected controls. We also investigated whether age, sex, body mass index (BMI), physical activity level, or lower back pain influence flexibility in HTLV-1-infected individuals. Methods The sample consisted of 56 adults, of which 15 did not have HTLV-1, 15 had HTLV-1 without myelopathy, and 26 had TSP/HAM. Their flexibility was assessed using the sit-and-reach test and a pendulum fleximeter. Results No differences in flexibility were observed between the groups with and without myelopathy and controls without HTLV-1 infection using the sit-and-reach test. The pendulum fleximeter results of individuals with TSP/HAM presented the lowest flexibility among the groups with respect to trunk flexion, hip flexion and extension, knee flexion, and ankle dorsiflexion, even after adjusting for age, sex, BMI, level of physical activity, and lower back pain using multiple linear regression models. Additionally, HTLV-1-infected individuals without myelopathy demonstrated reduced flexibility in movements: knee flexion, dorsiflexion, and ankle plantar flexion. Conclusions Individuals with TSP/HAM demonstrated reduced flexibility in most of the movements evaluated by the pendulum fleximeter. Additionally, HTLV-1-infected individuals without myelopathy demonstrated reduced knee and ankle flexibility, potentially representing a marker of myelopathic development.

Resumo Antecedentes A flexibilidade é fundamental para a execução harmoniosa dos movimentos articulares. Embora a disfunção do músculo esquelético em pacientes com HTLV-1 possa interferir na mobilidade, não está claro se esses pacientes apresentam flexibilidade reduzida. Objetivo Avaliar as diferenças de flexibilidade entre os indivíduos infectados com e sem mielopatia e o grupo controle sem infecção HTLV-1. Também investigamos se idade, sexo, índice de massa corporal (IMC), nível de atividade física ou dor lombar influenciam a flexibilidade em indivíduos infectados pelo HTLV-1. Métodos A amostra foi composta por 56 adultos, dos quais 15 não possuíam HTLV-1, 15 possuíam HTLV-1 sem mielopatia e 26 possuíam TSP/HAM. A flexibilidade foi avaliada por meio do teste de sentar e alcançar e do flexímetro de pêndulo. Resultados Não foram observadas diferenças na flexibilidade entre os grupos com e sem mielopatia no teste de sentar e alcançar. Os resultados do flexímetro pendular dos indivíduos com TSP/HAM apresentaram a menor flexibilidade entre os grupos em relação à flexão do tronco, flexão e extensão do quadril, flexão do joelho e dorsiflexão do tornozelo, mesmo após ajuste para idade, sexo, IMC, nível de atividade física e dor lombar usando modelos de regressão múltipla linear. Além disso, os indivíduos infectados pelo HTLV-1 sem mielopatia demonstraram redução da flexibilidade nos movimentos de flexão do joelho, dorsiflexão e flexão plantar do tornozelo. Conclusão Indivíduos com TSP/HAM demonstraram redução da flexibilidade na maioria dos movimentos avaliados pelo flexímetro pendular. Além disso, indivíduos infectados pelo HTLV-1 sem mielopatia demonstraram redução da flexibilidade do joelho e tornozelo, representando potencialmente um marcador de desenvolvimento mielopático.

Integrative and Multidisciplinary Care for People Living With Human T-Cell Lymphotropic Virus in Bahia, Brazil: 20 Years of Experience.

Brazil is home to the highest absolute number of human T-cell lymphotropic virus type-1 (HTLV-1)-infected individuals worldwide; the city of Salvador, Bahia, has the highest prevalence of HTLV-1 infection in Brazil. Due to the complex nature of several diseases associated with this retrovirus, a multidisciplinary health care approach is necessary to care for people living with HTLV-1. The Bahia School of Medicine and Public Health's Integrative Multidisciplinary HTLV Center (CHTLV) has been providing support to people living with HTLV and their families since 2002, striving to ensure physical and mental well-being by addressing biopsychosocial aspects, providing clinical care and follow-up, including to pregnant/postpartum women, as well as comprehensive laboratory diagnostics, psychological therapy, and counseling to family members. To date, CHTLV has served a total of 2,169 HTLV-infected patients. The average patient age is 49.8 (SD 15.9) years, 70.3% are female, most are considered low-income and have low levels of education. The majority (98.9%) are HTLV-1 cases, and approximately 10% have been diagnosed with tropical spastic paraparesis/HTLV-1-associated myelopathy (TSP/HAM), while 2.2% have infective dermatitis and 1.1% have adult T-cell lymphoma. In all, 178 pregnant/postpartum women [mean age: 32.7 (±6.5) years] have received care at CHTLV. Regarding vertical transmission, 53% of breastfed infants screened for HTLV tested positive in their second year of life, nearly 18 times the rate found in non-breastfed infants. This article documents 20 years of experience in implementing an integrative and multidisciplinary care center for people living with HTLV in Bahia, Brazil. Still, significant challenges remain regarding infection control, and HTLV-infected individuals continue to struggle with the obtainment of equitable and efficient healthcare.

Silencioso e negligenciado: o que se sabe após quatro décadas do descobrimento do HTLV-1? / Silent and neglected: what is known after four decades of the discovery of the HTLV-1? / Silencioso y descuidado: ¿qué se sabe después de cuatro décadas del descubrimiento del HTLV-1?

O vírus linfotrópico T humano tipo 1 (HTLV-1) foi o primeiro retrovírus humano descoberto, descrito pela primeira vez há 41 anos. Esse retrovírus está associado ao desenvolvimento de duas doenças graves: a leucemia/linfoma de células T do adulto (ATLL) e a mielopatia associada ao HTLV-1/paraparesia espástica tropical (HAM/TSP). Este trabalho teve como objetivo analisar as atualizações sobre o HTLV-1, destacando os aspectos clínicos, os avanços e as limitações no tratamento e na prevenção da infecção pelo HTLV-1. Para isso, foi realizada uma revisão integrativa, por meio de coleta de dados nas plataformas PubMed, LILACS e SciELO, entre março e abril de 2021. Foram incluídos 61 artigos de diferentes países. O Brasil foi o país com maior número de publicações na área: 12. Os resultados obtidos mostram que existem avanços importantes no que diz respeito ao tratamento e à prevenção da infecção pelo HTLV-1. No entanto, a falta de estudos específicos sobre o vírus, que abordem os aspectos clínicos da infecção, foi um fator limitante para este estudo, o que reforça a necessidade de investimento em novas pesquisas sobre o tema.

The Human T-lymphotropic Virus 1 (HTLV-1) was the first human retrovirus discovered, described for the first time 41 years ago. This retrovirus is associated with the development of two serious diseases: adult T-cell leukemia/lymphoma (ATLL) and tropical spastic paraparesis/HTLV-1-associated myelopathy (HAM/TSP). This study aimed to analyze the updates about HTLV-1, highlighting the clinical aspects, advances, and limitations in the treatment and prevention of HTVL-1 infection. To this end, an integrative review was carried out, with data collection on PubMed, LILACS, and SciELO platforms, between March and April 2021. A total of 61 articles from different countries were included. Brazil was the country with the largest number of publications in the area: 12. The results showed effective advances regarding treating and preventing HTLV-1 infection. However, the lack of specific studies about the virus, which address the clinical aspects of the infection, was a limiting factor for this study, which reinforces the need for investment in new research about this topic.

El virus linfotrópico T tipo 1 humano (HTLV-1) fue el primer retrovirus humano descubierto y se describió por primera vez hace 41 años. Este retrovirus está asociado con el desarrollo de dos enfermedades graves: leucemia/linfoma de células T del adulto (ATLL) e mielopatía asociada a HTLV-1/paraparesia espástica tropical (HAM/TSP). Este estudio tuvo como objetivo analizar las actualizaciones sobre HTLV-1, destacando los aspectos clínicos, los avances y limitaciones en el tratamiento y prevención de la infección por HTLV-1. Para ello, se realizó una revisión integradora, a través de la recolección de datos en las plataformas PubMed, LILACS y SciELO entre marzo y abril de 2021. Se incluyeron 61 artículos de diferentes países. Brasil fue el país con mayor número de publicaciones en el área: 12. Los resultados obtenidos muestran que existen avances efectivos en cuanto al tratamiento y prevención de la infección por HTLV-1. Sin embargo, la falta de estudios específicos sobre el virus que aborden los aspectos clínicos de la infección fue un factor limitante para el presente estudio, lo que refuerza la necesidad de invertir en nuevas investigaciones sobre este virus.

Molecular characterization of HTLV-1 genomic region hbz from patients with different clinical conditions.

The human T-cell lymphotropic virus type-1 (HTLV-1) is associated with severe pathologies, such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), adult T-cell leukemia-lymphoma (ATLL), and infective dermatitis associated with the HTLV-1 (IDH). Interestingly, HTLV-1 infection does not necessarily imply the development of pathological processes and it is unknown why some patients remain asymptomatic carriers (AC). Despite some mutations in the HTLV-1 genome appear to influence the outcome of HTLV-1, there are few studies that characterize molecularly the hbz region. This study aimed to perform the molecular characterization of hbz gene isolated from patients with different clinical outcomes. A total of 15 sequences were generated and analyzed with 571 sequences previously published. The analises showed that the R119Q mutation seems to be related to HTLV-1 clinical conditions since the frequency of this HBZ mutation is significantly different in comparison between AC with HAM/TSP and ATLL. The R119Q mutation is possibly a protective factor as the frequency is higher in AC sequences.

Complete genome sequence of human T-cell lymphotropic type 1 from patients with different clinical profiles, including infective dermatitis.

The HTLV-1 is the first human retrovirus and is associated with several clinical syndromes, however, the pathogenesis of these clinical manifestations is still not fully understood. Furthermore, there are few complete genomes publicly available, about 0.12 complete genomes per 10,000 infected individuals and the databases have a major deficiency of sequences information. This study generated and characterized 31 HTLV-1 complete genomes sequences derived from individuals with Tropical Spastic Paraparesis/HTLV-1-Associated Myelopathy (TSP/HAM), Adult T-cell leukemia/lymphoma (ATL), infective dermatitis associated to HTLV-1 (IDH) and asymptomatic patients. These sequences are associated to clinical and epidemiological information about the patients. The sequencing data generated on Ion Torrent PGM platform were assembled and mapped against the reference HTLV-1 genome. These sequences were genotyped as Cosmopolitan subtype, Transcontinental subgroup. We identified the variants in the coding regions of the genome of the different clinical profiles, however, no statistical relation was detected. This study contributed to increase of HTLV-1 complete genomes in the world. Furthermore, to better investigate the contribution of HTLV-1 mutations for the disease outcome it is necessary to evaluate the interaction of the viral genome and characteristics of the human host.

Assessment of Genetic Diversity of HTLV-1 ORF-I Sequences Collected from Patients with Different Clinical Profiles.

The human T cell lymphotropic virus type 1 (HTLV-1) infects 5 to 10 million individuals and remains without specific treatment. This retrovirus genome is composed of the genes gag, pol, env, and a region known as pX. This region contains four open reading frames (ORFs) that encode specific proteins. The ORF-I produces the protein p12 and its cleavage product, p8. In this study, we analyzed the genetic diversity of 32 ORF-I sequences from patients with different clinical profiles. Seven amino acid changes with frequency over 5% were identified: G29S, P34L, L55F, F61L, S63P, F78L, and S91P. The identification of regions where the posttranslational sites were identified showed a high identity among the sequences and the amino acid changes exclusive of specific clinical profile were found in less than 5% of the samples. We compare the findings with 2.406 sequences available in GenBank. The low overall genetic diversity found suggested that this region could be used in the HTLV-1 vaccine development.

Performance of Commercially Available Serological Screening Tests for Human T-Cell Lymphotropic Virus Infection in Brazil.

Serological screening for human T-cell lymphotropic virus type 1 (HTLV-1) is usually performed using enzyme-linked immunosorbent assay (ELISA), particle agglutination, or chemiluminescence assay kits. Due to an antigen matrix improvement entailing the use of new HTLV antigens and changes in the format of HTLV screening tests, as well as newly introduced chemiluminescence assays (CLIAs), a systematic evaluation of the accuracy of currently available commercial tests is warranted. We aimed to assess the performance of commercially available screening tests for HTLV infection diagnosis. A diagnostic accuracy study was conducted on a panel of 397 plasma samples: 200 HTLV-negative plasma samples, 170 HTLV-positive plasma samples, and 27 plasma samples indeterminate by Western blotting (WB). WB-indeterminate samples (i.e., those yielding no specific bands for HTLV-1 and/or HTLV-2) were assessed by PCR, and the results were used to compare agreement among the commercially available ELISA screening tests. For performance analysis, WB-indeterminate samples were excluded, resulting in a final study panel of 370 samples. Three ELISA kits (Murex HTLV-1/2 [Murex], anti-HTLV-1/2 SYM Solution [SYM Solution], and Gold ELISA HTLV-1/2 [Gold ELISA]) and one CLIA kit (Architect rHTLV-1/2) were evaluated. All screening tests demonstrated 100% sensitivity. Concerning the HTLV-negative samples, the SYM Solution and Gold ELISA kits had specificity values of >99.5%, while the Architect rHTLV-1/2 test presented 98.1% specificity, followed by Murex, which had a specificity of 92.0%. Regarding the 27 samples with WB-indeterminate results, after PCR confirmation, all ELISA kits showed 100% sensitivity but low specificity. Accuracy findings were corroborated by the use of Cohen's kappa value, which evidenced slight and fair agreement between PCR analysis and ELISAs for HTLV infection diagnosis. Based on the data, we believe that all evaluated tests can be safely used for HTLV infection screening.

Performance of commercially available serological screening Tests for human T-Cell lymphotropic virus infection in Brazil

ABSTRACT Serological screening for human T-cell lymphotropic virus type 1 (HTLV-1) is usually performed using enzyme-linked immunosorbent assay (ELISA), particle agglutination, or chemiluminescence assay kits. Due to an antigen matrix improvement entailing the use of new HTLV antigens and changes in the format of HTLV screening tests, as well as newly introduced chemiluminescence assays (CLIAs), a systematic evaluation of the accuracy of currently available commercial tests is warranted. We aimed to assess the performance of commercially available screening tests for HTLV infection diagnosis. A diagnostic accuracy study was conducted on a panel of 397 plasma samples: 200 HTLV-negative plasma samples, 170 HTLV-positive plasma samples, and 27 plasma samples indeterminate by Western blotting (WB). WB-indeterminate samples (i.e., those yielding no specific bands for HTLV-1 and/or HTLV-2) were assessed by PCR, and the results were used to compare agreement among the commercially available ELISA screening tests. For performance analysis, WB-indeterminate samples were excluded, resulting in a final study panel of 370 samples. Three ELISA kits (Murex HTLV-1/2 [Murex], anti-HTLV-1/2 SYM Solution [SYM Solution], and Gold ELISA HTLV-1/2 [Gold ELISA]) and one CLIA kit (Architect rHTLV- 1/2) were evaluated. All screening tests demonstrated 100% sensitivity. Concerning the HTLV-negative samples, the SYM Solution and Gold ELISA kits had specificity values of 99.5%, while the Architect rHTLV-1/2 test presented 98.1% specificity, followed by Murex, which had a specificity of 92.0%. Regarding the 27 samples with WB-indeterminate results, after PCR confirmation, all ELISA kits showed 100% sensitivity but low specificity. Accuracy findings were corroborated by the use of Cohen's kappa value, which evidenced slight and fair agreement between PCR analysis and ELISAs for HTLV infection diagnosis. Based on the data, we believe that all evaluated tests can be safely used for HTLV infection screening.

Molecular Epidemiology Database for Sequence Management and Data Mining.

A central database to aggregate sequence information from a range of epidemiological aspects including HTLV-1 pathogenesis, origin, and evolutionary dynamic would be useful to scientists and physicians worldwide. This Chapter describes two online tools for studies related to HTLV-1, the HTLV-1 Molecular Epidemiology Database and the HTLV-1 Subtyping Tool. The HTLV-1 Molecular Epidemiology Database is a tool for sequence management and data mining which allows researchers to download sequences with clinical and demographic information. The HTLV-1 Subtyping Tool is an online software used for HTLV-1 genotyping, the algorithm consists in the alignment of a query sequence with a carefully selected set of predefined reference strains, followed by phylogenetic analysis.