Human Lymphotropic Virus Research Articles

Effects of probiotics on clinical manifestations and inflammatory markers in HTLV-1-associated myelopathy/tropical spastic paraparesis: A triple blind randomized, placebo controlled trial

Human T-lymphotropic virus type 1 (HTLV-1), leads to adult T-cell lymphoma/leukemia (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in a minority of infected individuals. The virus promotes inflammation, a major factor in chronic disease progression. Probiotics' immune modulation and anti-inflammatory effects present a potential therapeutic intervention for HTLV-1-related conditions. This study investigates the impact of probiotics on both clinical manifestations and inflammatory markers in HAM/TSP patients.Conducted at the HTLV-1 clinic of Ghaem Hospital (Mashhad, Iran) between 2019 and 2020, this study randomized 40 HAM/TSP patients into two groups: an intervention group receiving 500 mg LactoCare capsules twice daily and a control group receiving placebo capsules of identical appearance for 12 weeks. Baseline and follow-up assessments included muscle strength, spasticity, motor disability, urinary disturbance, and serum levels of IL-10, IL-4, and IFN-γ (measured by ELISA). Post-intervention analysis revealed no significant differences between intervention and control groups in muscle strength, spasticity, and motor disability. However, significant improvement was observed in the intervention group regarding urinary symptoms after 12 weeks of initiation of intervention (P = 0.003). No significant changes were detected in serum levels of IL-10, IL-4, and IFN-γ between the two groups. The probiotics showed positive effects on urinary symptoms in HTLV-1-associated myelopathy/tropical spastic paraparesis patients but did not significantly impact other clinical or paraclinical parameters within the 12-week study period. These findings suggest that probiotics may offer symptomatic relief for some symptoms of HTLV-1-associated myelopathy/tropical spastic paraparesis patients.

Chinese expert consensus on the diagnosis and treatment of adult T-cell leukemia/lymphoma (2024)

Adult T-cell leukemia/lymphoma (ATL), a rare and unique proliferative tumor of T lymphocytes, is associated with human T-cell leukemia virus type 1 (HTLV-1) infection. Due to its diverse clinical features, multidrug resistance of malignant cells, frequent opportunistic infection, and poor prognosis, ATL remains a clinical challenge. A unified understanding of ATL is currently lacking, and its diagnosis and treatment are not standardized in China due to the small number of cases. Therefore, to strengthen our understanding of ATL, hematology experts have formulated the "Chinese expert consensus on the diagnosis and treatment of adult T-cell leukemia/lymphoma (2024)" based on the latest research progress at home and abroad. This consensus proposes the latest diagnostic and subtype criteria for ATL in China. Furthermore, it briefly describes the infection situation of HTLV-1 in coastal areas of China, the epidemic trends in China, and the latest evidence and recommendations regarding the pathogenesis, clinical manifestations, and treatment strategies, with the aim to standardize the clinical diagnosis and treatment of ATL and ultimately improve the overall survival of patients with ATL.

HTLV1 Infection in Patients with Common Endogenous Dermatitis

Background: Human T-cell Lymphotropic Virus type I (HTLV1) infection has been reported in patients with a variety of skin lesions in some parts of the world, especially in endemic areas. Infective Dermatitis associated with HTLV-1 (IDH) is the prototypic dermatologic manifestation of infection. However, to the best of our knowledge, it has not been reported in Iran as an endemic area yet. It is aimed to investigate the prevalence of HTLV1 infection among patients with common endogenous dermatitis. Methods: During a cross-sectional study, blood samples of 100 patients with both clinical and pathological diagnoses of common endogenous dermatitis including atopic, seborrheic, and nummular dermatitis who were referred to the Dermatology Clinic of Ghaem and Imam Reza Hospitals, Mashhad, Iran were obtained and evaluated for the presence of anti –HTLV-1 antibody using the ELISA method. The Polymerase Chain Reaction (PCR) for HTLV-1 was conducted in cases where the anti-HTLV1 antibody was positive. Statistical analysis was performed using SPSS version 16, Chicago, IL, USA. Results: Among 100 samples, two cases including erythrodermic dermatitis and atopic dermatitis were positive according to the ELISA method (2.0%). The dermatitis in HTLV1-positive patients was erythematous, scaly, with a generalized distribution and a recurrent nature, but did not complete the Infective Dermatitis (ID) criterion. Conclusion: In Iran as an endemic area, HTLV1-associated dermatitis may be present as recurrent generalized erythematous and scaly rash instead of known typical features of infective dermatitis.

A Novel Tax-Responsive Reporter T-Cell Line to Analyze Infection of HTLV-1.

Human T-cell leukemia virus type 1 (HTLV-1) infects CD4+ T-cells through close cell-cell contacts. The viral Tax-1 (Tax) protein regulates transcription by transactivating the HTLV-1 U3R promoter in the 5' long terminal repeat of the integrated provirus. Here, we generated a clonal Tax-responsive T-cell line to track HTLV-1 infection at the single-cell level using flow cytometry, bypassing intracellular viral protein staining. Jurkat T-cells stably transduced with the SMPU vector carrying green fluorescent protein (GFP) under control of 18 × 21 bp Tax-responsive element repeats of the U3R were evaluated. Among 40 clones analyzed for Tax responsiveness, the top two were characterized. Upon overexpression of Tax, over 40% of the cells showed GFP positivity, and approximately 90% of the Tax-positive cells were GFP-positive, indicating efficient reporter activity. However, with CREB-deficient Tax mutant M47, both total GFP-positive cell counts and those within the Tax-positive group significantly decreased. Co-culture with chronically HTLV-1-infected MT-2 or C91-PL cells led to an average of 0.9% or 2.4% GFP-positive cells, respectively, confirming the suitability to monitor HTLV-1 transmission and that HTLV-1 infection is very low. Thus, the novel Tax-responsive reporter T-cell line is a suitable tool to monitor infection of HTLV-1 on the single-cell level.

Rewired chromatin structure and epigenetic gene dysregulation during HTLV-1 infection to leukemogenesis.

Human T-cell leukemia virus type 1 (HTLV-1) broadly impacts host genes, affecting the infected cell population and inducing the development of a disease with a poor prognosis, adult T-cell leukemia-lymphoma (ATL). This study aimed to provide a comprehensive epigenomic characterization of the infected cell population and evaluated the transcriptome and chromatin structures of peripheral blood cells in HTLV-1-infected individuals using RNA sequencing (RNA-seq) and assay for transposase-accessible chromatin sequencing (ATAC-seq). The infected cells showed significant changes in gene expression patterns from the polyclonal stage and before ATL onset while demonstrating similarities to tumor-forming ATL cells. These similarities were a result of large-scale open chromatin changes, supporting the independent early formation of epigenomic aberrations as an underlying mechanism for later clonal propagation. This study also demonstrated that HTLV-1 Tax directly affects the host chromatin structure, thereby developing fundamental epigenomic characteristics. Several Tax target genes, including the RASGRP3-ERK pathway, were recognized, indicating an impact on signaling pathways. This genome-wide variability in chromatin structural property is a novel feature of HTLV-1 infection and may contribute to pathogenic mechanisms. In addition, it has crucial implications for better understanding the impact of HTLV-1 on the host genome and identifying novel therapeutic targets.

Construction of a cell cycle-specific lncRNA-miRNA-mRNA network reveals novel key lncRNAs in colorectal cancer

Objective The current study aimed to determine the roles of pivotal and novel lncRNAs associated with the cell cycle in the occurrence and development of Colorectal cancer (CRC). Methods The TCGA-COAD project related to CRC was downloaded, and differential expression analysis was performed to identify differentially expressed lncRNAs, miRNAs, and mRNAs. A cell cycle-associated lncRNA-miRNA-mRNA regulatory network was constructed, and two novel lncRNAs were selected. Two subnetworks were constructed for selected lncRNAs. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were illustrated for the genes in each sub-network. qPCR analysis was used to validate the expression levels of the selected lncRNAs in CRC tissues compared to those adjacent normal tissues. Results The differential expression analysis identified 416 lncRNAs, 317 miRNAs, and 117 mRNAs. The ceRNA subnetwork genes were associated with different pathways, including cellular senescence, DNA replication, human T-cell leukemia virus 1 infection, and oocyte meiosis. The bioinformatic results based on the TCGA project indicated the dysregulation of two novel lncRNAs, MIR29B2CHG and HELLPAR, in CRC tissues compared to adjacent normal tissues. Moreover, qPCR confirmed the dysregulation of lncRNAs in the CRC tissues. ROC curves revealed that both selected lncRNAs had acceptable specificity and sensitivity as biomarkers. Conclusion In conclusion, novel cell cycle-associated lncRNAs have the potential to be understood as the underlying molecular mechanisms that influence CRC. Therefore, these lncRNAs can be considered as promising biomarkers for the diagnosis and treatment of CRC.

Evaluation of anti-HIV-1 (Retroviridae: Orthoretrovirinae: Lentivirus: Human immunodeficiency virus type 1) activity of 6HP and 3TC in vitro using MT-4 cell line variants with different replicative activity.

Chemotherapy of HIV infection remains the only means of treating the disease. The process of development new and improving previously developed drugs is therefore considered a priority. One of the preclinical stage of drug efficacy testing is research in the virus-cell model system in vitro. To evaluate the antiviral efficacy of nucleoside reverse transcriptase inhibitors (NRTIs) 6HP and 3TC during HIV-1 replication in the neoplastic MT-4 cell line. Two variants of the CD4+ T-lymphocyte MT-4 cell line (MT-4/1 and MT-4/2) transformed by Human T-lymphotropic virus type 1 (Retroviridae: Orthoretrovirinae: Deltaretrovirus: HTLV-1), with different levels of HIV-1 replication were used. Drugs ammonium-3'-azido-3'-deoxythymidine-5'-carbomoylphosphonat (6HP) and 2',3'-dideoxy-3'-thiacytidine (3TC) were used to suppress the virus. The replication activity of HIV-1 was observed to be higher in the MT-4/2 line than in the MT-4/1 line for different strains of the virus. The use of each of the substances separately showed a more significant inhibition of viral activity in MT-4/1 than in MT-4/2 cells. When used together, the inhibition level was almost the same in all cases and ranged from 87‒96% for the MT-4/1 line and 83‒89% for the MT-4/2 line. High efficacy was observed when using lower concentrations of drugs compared to individual use. The combined use of NRTIs 6НР and 3TС is promising for the treatment of HIV-infected patients at different stages of infection and with different levels of viral load.

Reduction of antisense transcription affects bovine leukemia virus replication and oncogenesis.

In sheep infected with bovine leukemia virus (BLV), transcription of structural, enzymatic, and accessory genes is silenced. However, the BLV provirus transcribes a series of non-coding RNAs that remain undetected by the host immune response. Specifically, three RNAs (AS1-L, AS1-S, and AS2) are consistently expressed from the antisense strand, originating from transcriptional initiation at the 3'-Long Terminal Repeat (LTR). To investigate the role of these non-coding RNAs in viral replication and pathogenesis, a reverse genetics approach was devised, capitalizing on a mechanistic disparity in transcription initiation between the 5' and 3' promoters. A two-nucleotide mutation (GG>TA) in the TFIIB-recognition element (BRE) impaired antisense transcription originating from the 3'-LTR. In the context of the provirus, this 2bp mutation significantly diminished the expression of antisense RNAs, while not notably affecting sense transcription. When inoculated to sheep, the mutated provirus was infectious but exhibited reduced replication levels, shedding light on the role of antisense transcription in vivo. In comparison to lymphoid organs in sheep infected with a wild-type (WT) provirus, the mutant demonstrated alterations in both the spatial distribution and rates of cell proliferation in the lymph nodes and the spleen. Analysis through RNA sequencing and RT-qPCR unveiled an upregulation of the Hmcn1/hemicentin-1 gene in B-lymphocytes from sheep infected with the mutated provirus. Further examination via confocal microscopy and immunohistochemistry revealed an increase in the amount of hemicentin-1 protein encoded by Hmcn1 in peripheral blood mononuclear cells (PBMCs) and lymphoid organs of sheep infected with the mutant. RNA interference targeting Hmcn1 expression impacted the migration of ovine kidney (OVK) cells in vitro. In contrast to the WT, the mutated provirus showed reduced oncogenicity when inoculated into sheep. Collectively, this study underscores the essential role of antisense transcription in BLV replication and pathogenicity. These findings may offer valuable insights into understanding the relevance of antisense transcription in the context of human T-cell leukemia virus (HTLV-1).

The burden of HIV-1 and HIV-2 epidemics in Ivory Coast.

Simian immunodeficiency viruses (SIV) infecting chimpanzees (SIVcpz) and sooty mangabeys (SIVsm) are, respectively, the biological precursors of human immunodeficiency viruses (HIV) Types 1 and 2. Former French colonies in West Africa are the regions where retroviruses first jumped from primates to humans. Ivory Coast is nowadays a country of over 29 million people, being 2% (580,000) persons living with HIV (PLWH). However, one-quarter remains undiagnosed. Heterosexual transmission is by far the most frequent mechanism of HIV acquisition and women exhibit higher rates of infection than men. Despite preventive measures, HIV infection in children throughout breastfeeding remains significant. The proportion of PLWH carrying HIV-1 is rising whereas conversely HIV-2 carriers are steadily declining. A nationwide survey conducted on earlier 2024 showed that a total of 188,880 PLWH were on follow-up. HIV-1 infection was found in 163,947, HIV-2 in 5,114, and coinfection in 3,182. HIV type was not reported for 7,500. Antiretroviral therapy with tenofovir, lamivudine, and dolutegravir is by far the most frequently prescribed regimen in Ivory Coast (n = 168,543). Viral suppression is recognized in 94.3% of treated PLWH, despite one-third acknowledging unwanted treatment interruptions after failure of stock supplies. Given shared transmission routes with HIV, coinfection with other human retroviruses such as Human T-lymphotropic virus type-1 (HTLV-1) and/or hepatitis viruses B, C, and delta are frequent in Ivory Coast. Coinfections remain largely undiagnosed and poorly managed. In summary, the HIV pandemic caused by both HIV-1 and HIV-2 is a major public health challenge in Ivory Coast, where strategies for expanding diagnosis, sustain antiretroviral treatment, and manage coinfections warrant further efforts.

Correlation Between TWEAK Serum Level and HTLV-1 Proviral Load in HAM/TSP.

Human T-cell lymphotropic virus type-I (HTLV-I)-associated myelopathy/tropical spastic paraparesis (HAM/TSP), the main neurological manifestation of HTLV-I, is a chronic inflammatory disease. Viral-host interaction and host genetics are two important contributors to the development of the HAM/TSP. This study was conducted to measure the serum level of tumor necrosis factor-alpha-like weak inducer of apoptosis (TWEAK) by ELISA method in three groups of participants including 34 HAM/TSP patients (HAM/TSP), 35 asymptomatic HTLV-1 carriers (ACs), and 20 healthy controls (HCs). Also, the titer of the proviral load in two groups of HAM/TSP and ACs was assessed by the real-time polymerase chain reaction (PCR). The statistical results showed that, there is no significant difference between the three groups in TWEAK cytokine level (p = 0.667). Also, there was no significant difference in proviral load titer between groups of HAM/TSP and ACs (p = 0.08). Furthermore, no significant difference was observed between proviral load and TWEAK cytokine concentration between groups of HAM/TSP and ACs. Our findings showed that despite the inflammatory nature of HAM/TSP disease, the expression level of TWEAK in HAM/TSP patients is not significantly different from the groups of ACs and HCs. Therefore, the involvement of other factors in causing HAM/TSP is not unexpected.

Determinants in the HTLV-1 Capsid Major Homology Region that are Critical for Virus Particle Assembly

The Gag protein of retroviruses is the primary driver of virus particle assembly. Particle morphologies among retroviral genera are distinct, with intriguing differences observed relative to HIV-1, particularly that of human T-cell leukemia virus type 1 (HTLV-1). In contrast to HIV-1 and other retroviruses where the capsid (CA) carboxy-terminal domain (CTD) possesses the key amino acid determinants involved in driving Gag-Gag interactions, we have previously demonstrated that the amino-terminal domain (NTD) encodes the key residues crucial for Gag multimerization and immature particle production. Here in this study, we sought to thoroughly interrogate the conserved HTLV-1 major homology region (MHR) of the CACTD to determine whether this region harbors residues important for particle assembly. In particular, site-directed mutagenesis of the HTLV-1 MHR was conducted, and mutants were analyzed for their ability to impact Gag subcellular distribution, particle production and morphology, as well as the CA-CA assembly kinetics. Several key residues (i.e., Q138, E142, Y144, F147 and R150), were found to significantly impact Gag multimerization and particle assembly. Taken together, these observations imply that while the HTLV-1 CANTD acts as the major region involved in CA-CA interactions, residues in the MHR can impact Gag multimerization, particle assembly and morphology, and likely play an important role in the conformation the CACTD that is required for CA-CA interactions.

EZH2 Activates HTLV-1 bZIP Factor-Mediated TGF-β Signaling in Adult T-Cell Leukemia.

Adult T-cell leukemia (ATL) is an aggressive malignancy caused by human T-cell leukemia virus type 1 (HTLV-1) infection. Enhancer of zeste homolog 2 (EZH2) has been implicated in the development and progression of multiple cancers, including virus-induced malignancies. However, the potential function of EZH2 in HTLV-1-induced oncogenesis has not been clearly elucidated. In the present study, we showed that EZH2 was overexpressed and activated in HTLV-1-infected cell lines, potentially due to the activation of EZH2 promoter by HTLV-1 Tax and NF-κB p65 subunit. In addition, we found that EZH2 enhanced the HBZ-induced activation of TGF-β signaling in a histone methyltransferase-independent manner. As a mechanism for these actions, we found that EZH2 targeted Smad3/Smad4 to form a ternary complex, and the association between Smad3 and Smad4 was markedly enhanced in the presence of EZH2. Knockdown of EZH2 in ATL cells indeed repressed the expressions of the TGF-β target genes. In particular, EZH2 synergistically enhanced the HBZ/TGF-β-induced Foxp3 expression. Treatment of 3-Deazaneplanocin A, a specific inhibitor of EZH2 significantly inhibited the Foxp3 expression. Taken together, our results suggest that EZH2 may be involved in the differentiation of regulatory T cells through activating the HBZ-Smad3-TGF-β signaling axis, which is considered to be a key strategy for viral persistence.

First report on human T-lymphotropic virus 1 infection in a group of transgender women.

There is a lack of data on human T-lymphotropic virus 1 (HTLV-1) infection among transgender women (TGW). Therefore, this study estimated the prevalence of HTLV-1 infection in a group of TGW in Brazil. A cross-sectional study was conducted with 235 TGW in Goiânia City, Central Brazil. Respondent-driven sampling was used for recruitment. All participants were interviewed, and serum samples were tested for anti-HTLV-1/2 using an enzyme-linked immunosorbent assay (ELISA; Murex HTLV-I + II, DiaSorin, Dartford, United Kingdom). Seropositive samples were submitted for confirmation by Western blot (WB; MP Diagnostics HTLV BLOT 2.4 test, MP Biomedicals, Germany). The majority of participants were young (≤ 25 years old), self-declared mixed or brown ethnicity, single, had attended high school, and had a monthly income above US$ 255 (R$ 1,000,00; nearly the minimum wage in Brazil at the time). Most reported earlier age at first sex and various risk behaviors for sexually transmitted infections (STIs). Three TGW were anti-HTLV-1/2 positive by ELISA and were subsequently positive for HTLV-1 by WB, giving a crude HTLV-1 seroprevalence of 1.3%; 1.0% (95% CI: 0.0-1.9) after being weighted by RDS Analysis Tool (RDSAT). The HTLV-1 seropositive TGW reported high-risk sexual behaviors. In addition, one of them also engaged in injecting drug use. These data indicate the circulation of HTLV-1 in TGW in Goiânia City, Central Brazil. Given the alarming estimates of high-risk sexual behaviors, there is an urgent need to intensify health programs targeting this population to control and prevent HTLV-1 and other STIs effectively.

Antiviral immune response against HTLV-1 invalidates T-SPOT.TB® results in patients with HTLV-1-positive rheumatic diseases.

T-SPOT.TB®, one of the screening tests for latent tuberculosis infection (LTBI), yields invalid results in human T-cell leukemia virus type 1 (HTLV-1)-positive patients with rheumatoid arthritis. However, the detailed mechanisms behind this invalidation are unclear. Additionally, it remains unclear whether T-SPOT.TB® or QuantiFERON-TB (QFT) is more useful in HTLV-1-positive patients with rheumatic disease (RD). Among all of the HTLV-1-positive RD patients who visited our department between August 2012 and December 2022, 44 patients who were screened using T-SPOT.TB® were included in the analysis. QFT testing was performed in 33 of the 44 patients, and the results were compared with that of T-SPOT.TB®. Furthermore, we performed a culture experiment mimicking T-SPOT.TB® using peripheral blood mononuclear cells (PBMCs) obtained from HTLV-1-positive patients with RD. Additionally, T-cell subsets with autonomous product IFN-γ were analyzed using a flow cytometer. Of the included patients, 13 (29.5%) were invalid for T-SPOT.TB® because of the increased number of negative control spots. The median HTLV-1 proviral load in the invalid group was higher than that in the valid group (2.45 vs. 0.49 copies/100 PBMCs, respectively, p = 0.002). QFT was performed in all 33 patients, including 13 patients who were invalid in T-SPOT.TB®. The main source of IFN-γ production was CD8+ T-cells in the T-SPOT.TB® mimic experiment. Furthermore, Tax-expressing CD4+ T-cells and Tax-specific cytotoxic CD8+ T-cells were more frequently observed in patients with invalid results than in patients with valid results. CD4+ T-cell depletion in the T-SPOT.TB® mimic experiment reduced the population of IFN-γ producing CD8+ T cells. T-SPOT.TB® may be invalidated by the interaction between Tax-expressing CD4+ T-cells and cytotoxic CD8+ T-cells. Moreover, HTLV-1-associated immune reactions due to contact between these cells may be unlikely to occur in QFT using whole blood. Therefore, our results reveal the superiority of QFT over T-SPOT.TB® as a screening test for LTBI in HTLV-1-positive patients with RD.

Current State of Therapeutics for HTLV-1

Human T cell leukaemia virus type-1 (HTLV-1) is an oncogenic retrovirus that causes lifelong infection in ~5–10 million individuals globally. It is endemic to certain First Nations populations of Northern and Central Australia, Japan, South and Central America, Africa, and the Caribbean region. HTLV-1 preferentially infects CD4+ T cells and remains in a state of reduced transcription, often being asymptomatic in the beginning of infection, with symptoms developing later in life. HTLV-1 infection is implicated in the development of adult T cell leukaemia/lymphoma (ATL) and HTLV-1-associated myelopathies (HAM), amongst other immune-related disorders. With no preventive or curative interventions, infected individuals have limited treatment options, most of which manage symptoms. The clinical burden and lack of treatment options directs the need for alternative treatment strategies for HTLV-1 infection. Recent advances have been made in the development of RNA-based antiviral therapeutics for Human Immunodeficiency Virus Type-1 (HIV-1), an analogous retrovirus that shares modes of transmission with HTLV-1. This review highlights past and ongoing efforts in the development of HTLV-1 therapeutics and vaccines, with a focus on the potential for gene therapy as a new treatment modality in light of its successes in HIV-1, as well as animal models that may help the advancement of novel antiviral and anticancer interventions.

Flower-Shaped Plasma Cells in Multiple Myeloma with Morphological Heterogeneity.

Flower-shaped nuclei in plasma cells are rare in multiple myeloma. We report on an 88-year-old male who presented with a mass lesion in the clavicular region. A biopsy of the mass revealed an increase in mature plasma cells with round nuclei. In contrast, a bone marrow examination showed increased plasma cells with flower-shaped nuclei. The patient tested negative for human T-lymphotropic virus type-1 and was diagnosed with multiple myeloma. While multiple myeloma is known for intra-tumor heterogeneity, reports of morphological heterogeneity based on the site of tumor sampling are limited. In this case, the presence of plasma cells with flower-shaped nuclei enabled the identification of site-dependent morphological tumor heterogeneity.

Cognitive Assessment in HTLV-1 Patients Followed Up at a Reference Center in Salvador, Brazil.

Human T-cell lymphotropic virus type 1 (HTLV-1) is endemic to Brazil, and there is still no specific treatment for these patients. The literature shows that few studies have described the cognitive impairment associated with an HTLV-1 infection, with none of them examining the population of Salvador, where there are approximately forty thousand people infected with the virus. To determine the prevalence of cognitive impairment among individuals with HTLV-1. In addition, investigate whether sociodemographic aspects, time since the diagnosis of infection, and the diagnosis of HTLV-Associated Myelopatia/Tropical Spastic Paraparesis (HAM/TSP) or depression are associated with cognitive impairment in this population. This was an observational, cross-sectional study that consisted of consecutively approaching 100 HTLV-1 patients during outpatient care at a referral center followed by the administration of three questionnaires- the Mini Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), and Beck's Depression Inventory. The prevalence of cognitive impairment found was 71% using the MMSE and 82% using the MoCA. There was a statistically significant association between the cognitive dysfunction and the variables of age and education according to the MoCA analysis but not the MMSE data. Diagnosis of HAM/TSP was correlated with cognitive impairment using the MMSE but not the MoCA. The prevalence of depression was 20%, and there was no association between cognitive impairment and depressive symptoms in these patients. The findings of this study demonstrate a correlation between cognitive dysfunction and HTVL-1 infection, with a more evident involvement of executive functions and memory. Larger studies are needed to clarify the association between cognitive dysfunction, age, education, and the diagnosis of HAM/TSP.

B-099 Validation and Clinical Implementation of Organ Procurement Serology Testing: Our Analytical and Regulatory Experience in Implementing a New Donor Testing Program

Abstract Background The Mount Sinai Hospital recently implemented a comprehensive organ donor testing program to service the clinical needs of transplant services in the New York City metro area. Conventional serology testing is not approved by the FDA for donor testing. To support this program, the MSH Chemistry Laboratory implemented and validated a comprehensive donor testing panel on the Abbott Alinity S donor testing platform. We validated donor serology testing for the following assays: HIV-1/2 (HIV), Anti-Hepatitis B Core (Anti-HBc), Hepatitis B Surface Antigen (HBsAg), Human T-lymphotropic virus I and II (HTLV-I/II), Anti-Hepatitis C (Anti-HCV), and Trypanosoma cruzi antibodies (T.Cruzi). The Alinity S System is an automated immunoassay-based analyzer FDA-approved for donor testing. The analyzer consists of two distinct sample ‘paths’ and is effectively two instruments combined in one analyzer. The analyzer is approved for use in living donor serum and plasma and in cadaveric serum. Prior to going live, we found that there was limited guidance on laboratory quality assurance programs related to donor testing. In addition to confirming assay analytical performance, we designed and implemented a comprehensive quality assurance program prior to satisfy compliance with regulatory guidelines, addressing proficiency compliance, sample TAT, and control ranges, amongst other quality indicators. Methods Inter and Intraday precision was assessed through replicate analysis of positive and negative controls, where 10 replicates of both controls were assayed on a single day, and one replicate of each control was assayed daily for 7 distinct days, results were represented as %CV. Result accuracy was assessed through split sample analysis of known serologically positive (n=20) and negative samples (n=40). Each sample was assayed on two distinct lots of reagents, each with its own unique calibration curve. Accuracy was confirmed in both living donor (n=30), and cadaveric samples (n=10). In addition, split sample analysis was performed between the Alinity S and FDA-approved donor testing assays in a reference laboratory (N=7). A carryover study was performed through the analysis of triplicate replicates of low, high, and then low controls. These analyses were performed for all 6 assays. Results Intraday precision using assay general controls afforded the following %CV: HIV: 3.1%, 6.5%; Anti-HBc: 1.3%, 2.6%; Anti-HCV: 3.3%, 11.7%; HTLV-I,II: 2.5%, 5.9%; T.Cruzi: 2.8%, 0%; HBsAg: 3.2%, 11.6%. Interday precision yielded the following in %CV: HIV: 2.9%, 10.0%; Anti-HBc: 3.0%, 5.6%; Anti-HCV: 3.3%, 3.4%; HTLV-I,II: 2.8%, 4.6%; T.Cruzi: 2.4%, 0%; HBsAg: 4.7%, 7.8%. Accuracy studies yielded 100% positive and negative correlation for all 6 assays in both living donor and cadaveric samples. In addition, there was a 100% serological correlation for samples compared to reference laboratories. Carryover studies showed no evidence of sample carryover. Conclusions The Abbott Alinity S shows acceptable assay precision on all 6 validated assays. The assays are serologically accurate in both cadaveric and living donor samples. As such, the assays and platform are acceptable for use in donor screening. We designed a unique quality assurance program including a comprehensive self-proficiency and instrument crosscheck program to ensure analyzer accuracy, as well as adherence to regulatory guidelines.

Sexual transmission of HTLV-1 resulting in uveitis with short-term latency and low proviral load.

Human T-cell Lymphotropic Virus Type 1 (HTLV-1) is traditionally linked to severe conditions such as adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy, and HTLV-1 uveitis, with vertical transmission, particularly mother to child thorough breastfeeding, considered the primary route. Despite efforts to reduce vertical transmission through antenatal screening in Japan, horizontal transmission has contributed to the rising prevalence of HTLV-1 in metropolitan areas. This case reports the youngest documented instance of HTLV-1 uveitis resulting from horizontal transmission through sexual contact in an 18-year-old woman. The patient presented with blurred vision in her right eye, and a comprehensive ophthalmologic examination identified vitreous opacity and retinal vasculitis. Serological tests confirmed HTLV-1 infection, with a proviral load of 2.66 copies per 100 peripheral blood mononuclear cells, measured by real-time PCR. A differential diagnosis confirmed HTLV-1 uveitis. Further family and partner investigations confirmed horizontal transmission, most likely through sexual contact. Over 6 years of follow-up, the patient experienced multiple recurrences of HTLV-1 uveitis and developed HTLV-1-associated keratopathy. This case highlights the potential for rapid disease progression with relatively low proviral loads and short latency, emphasizing the need for updated public health strategies for sexually active young populations.

The Assembly of HTLV-1-How Does It Differ from HIV-1?

Retroviral assembly is a highly coordinated step in the replication cycle. The process is initiated when the newly synthesized Gag and Gag-Pol polyproteins are directed to the inner leaflet of the plasma membrane (PM), where they facilitate the budding and release of immature viral particles. Extensive research over the years has provided crucial insights into the molecular determinants of this assembly step. It is established that Gag targeting and binding to the PM is mediated by interactions of the matrix (MA) domain and acidic phospholipids such as phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This binding event, along with binding to viral RNA, initiates oligomerization of Gag on the PM, a process mediated by the capsid (CA) domain. Much of the previous studies have focused on human immunodeficiency virus type 1 (HIV-1). Although the general steps of retroviral replication are consistent across different retroviruses, comparative studies revealed notable differences in the structure and function of viral components. In this review, we present recent findings on the assembly mechanisms of Human T-cell leukemia virus type 1 and highlight key differences from HIV-1, focusing particularly on the molecular determinants of Gag-PM interactions and CA assembly.