Detection of human T-lymphotropic virus (HTLV) tax sequences in New York City blood donors seronegative for HTLV types 1 and 2.
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ABSTRACT:
SUBMITTER: Dezzutti CS
PROVIDER: S-EPMC164244 | biostudies-other | 2003 Jul
REPOSITORIES: biostudies-other
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Project description:X-box binding protein 1 (XBP-1), a basic leucine zipper transcription factor, plays a key role in the cellular unfolded protein response (UPR). There are two XBP-1 isoforms in cells, spliced XBP-1S and unspliced XBP-1U. XBP-1U has been shown to bind to the 21-bp Tax-responsive element of the human T-lymphotropic virus type 1 (HTLV-1) long terminal repeat (LTR) in vitro and transactivate HTLV-1 transcription. Here we identify XBP-1S as a transcription activator of HTLV-1. Compared to XBP-1U, XBP-1S demonstrates stronger activating effects on both basal and Tax-activated HTLV-1 transcription in cells. Our results show that both XBP-1S and XBP-1U interact with Tax and bind to the HTLV-1 LTR in vivo. In addition, elevated mRNA levels of the gene for XBP-1 and several UPR genes were detected in the HTLV-1-infected C10/MJ and MT2 T-cell lines, suggesting that HTLV-1 infection may trigger the UPR in host cells. We also identify Tax as a positive regulator of the expression of the gene for XBP-1. Activation of the UPR by tunicamycin showed no effect on the HTLV-1 LTR, suggesting that HTLV-1 transcription is specifically regulated by XBP-1. Collectively, our study demonstrates a novel host-virus interaction between a cellular factor XBP-1 and transcriptional regulation of HTLV-1.
| S-EPMC2293026 | biostudies-literature
Project description:BACKGROUND AND OBJECTIVES:Donated blood is not currently screened for human T-cell lymphotropic virus (HTLV) in South Africa. Several small studies have detected HTLV-1 in South Africa, but prevalence by geographic region or population group is unavailable. MATERIALS AND METHODS:We performed a large seroprevalence study of South African blood donors during 3 months in 2013. All geographic regions except the Western Cape were included, and Black and Coloured (local term for mixed race) donors were oversampled. Identity-unlinked plasma samples were screened with the Abbott Prism HTLV-1/2 assay, and repeatedly reactive samples were tested by the Inno-LIA HTLV-1/2 Score confirmatory assay. Odds ratios were calculated with multivariable logistic regression. RESULTS:Of 46 752 donors tested, 133 (0·28%) were initially reactive, 111 (0·24%) repeatedly reactive and 57 (0·12%) confirmed positive for HTLV-1; none were HTLV-2 positive. Prevalence was 0·062% weighted to annual blood donations but highly concentrated in the Black population group (OR = 20·24 CI: 2·77-147·88); higher in females than males (OR = 1·81 CI: 1·06-3·08); and in donors aged >50 years compared to ages 16-19 (OR = 6·4 CI: 2·95-13·86). After controlling for age, sex and population group, there was no difference in prevalence between new and repeat blood donors or among geographic regions within South Africa. CONCLUSIONS:We conclude that HTLV-1 infection is widespread among the Black population of South Africa and its epidemiology is similar to other endemic areas. Because South Africa is increasing its recruitment of Black blood donors, the implications for blood screening require further consideration.
| S-EPMC7413069 | biostudies-literature
Project description:It is unknown whether HTLV-1/2 prevalence has been stable or changing with time in Brazil. We present a 10-year (2007-2016) analysis of HTLV-1/2 infection in first-time blood donors from four blood banks in Brazil. The Brazilian blood centers participating in this multicenter Recipient Epidemiology and Donor Evaluation Study (REDS) are located in Recife in the Northeast and in São Paulo, Rio de Janeiro and Belo Horizonte located in the Southeast of the country. A previous REDS study using the same database from 2007 to 2009 showed that the prevalence per 100,000 donors was 222 in Recife, 83 in Belo Horizonte and 101 in São Paulo. From 2007 to 2016, HTLV-1/2 prevalence was calculated by year, blood center and birth cohort. Covariates included age, gender, schooling, self-reported skin color and type of donation. From 1,092,174 first-blood donations, in the general analysis, HTLV-1/2 infection predominated in females, donors over 50 years of age, black skin color and less educated. The average prevalence was 228 per 100,000 donors in Recife, 222 in Rio de Janeiro, 104 in Belo Horizonte and 103 in São Paulo. In the 10-year analysis, HTLV-1/2 prevalence was stable, but a trend was observed toward an increase in HTLV-1/2 infection among younger people (p < 0.001), males (p = 0.049), those with white skin color (p < 0.001), and higher education (p = 0.014). Therefore, this 10-year surveillance of the infection showed stable HTLV-1/2 prevalence overall but a trend toward increased prevalence among the younger and more educated donors despite Brazilian policies to control sexually transmitted infections being in place for more than 10 years.
| S-EPMC8959844 | biostudies-literature
Project description:BackgroundResearch on HTLV in Colombia is limited; despite being an endemic country there are few studies on the magnitude of this infection. The aim of this study was to determine the seroprevalence of HTLV I/II and its associated factors in donors to a blood bank of Medellín Colombia, 2014-2018.MethodsThis is a cross-sectional study of 52,159 donors with a secondary information source. Seroprevalence of HTLV I/II was determined with its confidence interval and the population characteristics were described by frequency and summary measures. To explore the associated factors, Pearson's Chi square test, Mann-Whitney U test, crude odds ratios were used and they were adjusted by logistic regression in SPSS 25.0.Results88% of the population lived in the metropolitan area, 68.5% belonged to the University. 76.2% were altruistic donors (unpaid donors who did not donate to a specific patient). 24.5% were repetitive (paid) donors. 75% of the donors were under 41 years old. The seroprevalence of HTLV I/II was 0.176% (95% CI = 0.139% -0.213%), being statistically lower in repetitive donors and men.ConclusionThe seroprevalence of HTLV I/II infection in the studied blood bank is lower than that reported in other blood banks at the departmental and national levels. In Medellín, it was associated with the frequency of donation and gender, which is useful information for the hemovigilance programs of the city.
| S-EPMC6690513 | biostudies-literature
Project description:Antipoverty policies may hold promise as tools to improve health and reduce mortality rates among low-income Americans. We examined the health effects of the New York City Paycheck Plus randomized controlled trial. Paycheck Plus tests the impact of a potential fourfold increase in the Earned Income Tax Credit for low-income Americans without dependent children. Starting in 2015, Paycheck Plus offered 5,968 study participants a credit of up to $2,000 at tax time (treatment) or the standard credit of about $500 (control). Health-related quality of life and other outcomes for a representative subset of these participants (n = 3,289) were compared to those of a control group thirty-two months after randomization. The intervention had a modest positive effect on employment and earnings, particularly among women. It had no effect on health-related quality of life for the overall sample, but women realized significant improvements.
| S-EPMC7909715 | biostudies-literature
Project description:The prevalence of infection with human T-cell lymphotropic virus type 1 (HTLV-1) in blood donors from Israel is 1 infection/100,000 persons. In donors originating from Eastern Europe, the Middle East, and Latin America, prevalences are 7.7, 14.6, and 20.4, respectively. HTLV-1 prevalence may be high outside areas where HTLV-1 previously was known to be endemic.
| S-EPMC2744246 | biostudies-literature
Project description:In some areas of Argentina endemic for human T-lymphotropic virus type 1 (HTLV-1), tropical spastic paraparesis is frequent in subjects who lack antibodies against the virus; however, the relevance of this seronegative status in the country has not been investigated. In neighboring countries, HTLV-1 seronegative status has been described in patients with different diseases; however, data regarding features of seronegative HTLV-1 carriers are scarce. We investigated the seronegative status in 124 relatives of 28 HTLV-1 infected subjects from an endemic area in Northwest Argentina. Blood samples and clinical/epidemiological data were collected. Human T-lymphotropic virus type 1 infection was diagnosed by serology and long terminal repeat (LTR) sequence, env and tax gene detection. IgG anti-Tax HTLV-1 antibody, tax gene sequence, and DNA proviral load were also evaluated. Seventy-five percent of the 124 relatives were negative for HTLV-1/2 antibodies; 35.5% were also negative by molecular assays and 64.5% were negative for HTLV-1 LTR and env sequences, but positive for two sequences of HTLV-1 tax gene. Also, 35.7% of these subjects had IgG anti-Tax antibodies. The seronegative HTLV-1 status was significantly associated with male gender, youth, and sensory symptoms/autonomic nervous system dysfunction. High rates of seronegative symptomatic and asymptomatic HTLV-1 carriers in Argentina are described. The evidence highlights that HTLV-1 prevalence may be underestimated worldwide. Larger cohort studies are required to assess disease outcome in these seronegative subjects. Also, the findings emphasize the limitations of ongoing screening assays for diagnosis and blood safety. Therefore, algorithms for HTLV-1 diagnosis should include not only serological but also molecular assays.
| S-EPMC7124914 | biostudies-literature
Project description:BackgroundThe human T-lymphotropic virus type 1 (HTLV-1) which is associated with the diseases of adult T-cell leukemia/lymphoma, HTLV-1 associated myelopathy / tropical spastic paraparesis (HAM/TSP) and HTLV-associated uveitis, can cause transfusion-transmitted infections. Although HTLV screening of blood donors was already routinely performed in developed countries, little is know about the HTLV prevalence among blood donors in developing countries which do not perform HTLV screening, such as China.Objectives &aimsTo systematically characterize the prevalence of HTLV infection among bloods in southeast China.MethodsA 10-year survey for HTLV prevalence in blood donors was performed in Xiamen, southeast China, during 2004-2013. The HTLV-1/2 of blood donations were screened by enzyme-linked immunosorbent assay, following with confirmation by western blot assay and 9nucleic acid testing. The HTLV-1 prevalences in donors from different cities were calculated. Viral sequences derived from identified HTLV-positive cases were sequenced and analyzed.ResultsAmong 253,855 blood donors, 43 were confirmed to be seropositive for HTLV-1 (16.9 per 100,000 95% CI: 12.3-22.8) and none HTLV-2 infection was found. The HTLV-1 prevalence varied significantly in donors from different cities. Donors from cities in Fujian province (24.3 per 100,000, 95%CI: 17.4-33.1) had a significantly higher (p=0.001) HTLV-1 seroprevalence than those who were born in non-Fujian cities (3.4 per 100,000, 95%CI: 0.7-9.8). Among nine cities in Fujian province, the highest prevalence was found in blood donors from Ningde (171.3 per 100,000, 95%CI: 91.3-292.8) which is a coastal city in the northeast of Fujian. Molecular characterization of viral sequences from 27 HTLV-1 carriers revealed 25 were Transcontinental subtype of genotype A and 2 were Japanese subtype of genotype A. Interestingly, 12 of 25 Transcontinental subtype sequences harbored a characteristic L55P mutation in viral gp46 protein, which was only presented in the Transcontinental subtype sequences from Japan and Taiwan but not in that from other countries.ConclusionsAlthough China is considered to be a non-endemic region for HTLV, the HTLV-1 prevalence in blood donors is significantly higher in Fujian province, southeast China. A higher prevalence of HTLV-1 in the Fujian may be attributed to endemic foci in the city of Ningde.
| S-EPMC4382043 | biostudies-literature
Project description:Human T-cell lymphotrophic virus type I and II (HTLV-I/II) are closely related but distinct retroviruses that can infect humans. Both the viruses can be transmitted via transfusion of contaminated blood components. HTLV pre-transfusion screening is not mandatory in Thailand until now. Current epidemiological data for HTLV prevalence is still lacking since the past surveys were done more than a decade ago. The main objective of this study was to determine the seroprevalence of HTLV-I/II among voluntary blood donors in Thailand. 11,057 volunteer blood donors were screened for HTLV-I/II antibodies using the ARCHITECT rHTLV-I/II chemiluminescent immunoassay (CLIA). Initial-reactive (IR) samples were subjected to repeat duplicate testing and were also sent for confirmatory testing at Korean Red Cross Society (KRC), Seoul or National Serology Reference Laboratories (NRL), Australia using alternate HTLV serological assays and immunoblot and/or specific nucleic acid testing respectively. Out of 11,057 plasma samples, 10,080 were low-risk seronegative donors and 977 were first-time/high-risk donors. Twenty of 24 IR samples were repeatedly reactive (RR) in low-risk seronegative donors group. On confirmatory testing of these 24 IR by immunoblot, 13 indeterminate and 11 negative results were observed. One out of 977 samples from first-time/high-risk donors was RR for anti-HTLV-I/II antibodies. This sample was co-reactive for HBsAg, but negative for HTLV by EIA or in-house HTLV-I qPCR. The ARCHITECT rHTLV-I/II assay exhibited a specificity of 99.93% in low-risk donors and 99.90% among high-risk donors. This study concluded that HTLV-I/II prevalence is low among blood donors in Thailand. But periodic surveillance should be continually conducted to ensure high blood safety standards in the country.
| S-EPMC6300747 | biostudies-literature
Project description:BackgroundSo far, the prevalence of human T-lymphotropic virus (HTLV) type 1 and 2 in some highly populated countries such as China is still unknown. In this study, a multi-center nationwide serological survey was designed and performed, to reveal the seroprevalence of HTLV infection among Chinese blood donors.ResultsAmong 8,411,469 blood donors from 155 blood establishments, 435 were finally confirmed as HTLV carriers. The prevalence of HTLV infection in China varied in different provinces: Fujian had the highest prevalence of 36.240/100,000 (95% CI 31.990-41.050) and eleven provinces did not find HTLV-seropositive donors in the three years. no HTLV-2 infection was found. The overall prevalence of HTLV-1 in China decreased from 2016 to 2018. Female was identified as an independent risk factor of HTLV infection in China. Besides, seroconversion was observed in two of seven seroindeterminate donors 85 and 250 days after their last donation, respectively.ConclusionsThe seroprevalence of HTLV infection in most areas of China among blood donors is quite low, but it varies significantly in different geographic areas. Screening anti-HTLV-1/2 antibody and follow-up of serointederminate donors are essential to ensure blood safety especially in areas where we have found HTLV infected donors.
| S-EPMC7791705 | biostudies-literature