Trends in the prevalence and distribution of HTLV-1 and HTLV-2 infections in Spain

HTLV-1 Proviral Load Absolute RT-qPCR Development for Assessing on Clinical Outcomes in HAM/TSP Patients

Background

The significance of HTLV-1 proviral load as a prognostic biomarker in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) has been a subject of controversy. This study aims to assess the impact of HTLV-1 proviral load (PVL) on the clinical outcome in patients with HAM/TSP.

Methods

An absolute quantitative HTLV-1 PVL RT-qPCR, TaqMan method was developed with 100% sensitivity and specificity. Then, from 2005-2018, the HTLV-1 PVL of 90 eligible newly diagnosed HAM/TSP patients were assessed for demographic, clinical symptoms and their associations with HTLV-1-PVL.

Results

The quality control of the designed RT-qPCR showed a sensitivity and specificity of 100%. Spasticity in lower limbs in 58.9% and urinary symptoms in 17.8% of HAM/TSPs were observed. Using this designed RT-qPCR, the HTLV-1-PVL strongly affected spasticity and sphincter disturbance (p=0.05). The multivariate logistic test showed that only the beginning of lower limb weakness along with tremor was associated with PVL (OR: 2.78. 95% CI (0.99-1.02) and p=0.05). Urinary incontinence was prevalent among these patients; however, no association was identified with the HTLV-1 proviral load (PVL).

Conclusions

The absolute RT-qPCR developed for measuring HTLV-1 proviral load (PVL) demonstrated reliable results. Despite a high prevalence of urinary incontinence in these patients, no association was observed with the PVL. Consequently, it appears that HTLV-1 proviral load is specifically associated with developing spasticity in HAM/TSP.

Human T Cell Lymphotropic Virus Type 1 Global Prevalence Associated with the Human Development Index: Systematic Review with Meta-Analysis

In 2012, the number of people infected with human T cell lymphotropic virus type 1 (HTLV-1) was estimated to be 10 million worldwide. Prevalence varies according to geographic location, ethnic factors, sex, age, populations exposed to risk factors, income, and education, reaching countries with the worst socioeconomic scenarios. There is a need to determine the current global prevalence of HTLV-1 and examine its association with countries' human development index (HDI) to provide data for global health policy. Systematic review with meta-analysis is according to PRISMA 2020 recommendations. It was registered at PROSPERO, CRD42021223146. Prevalence or cross-sectional studies of HTLV-1 infection with at least 100 participants, screening, and confirmatory serologic testing were included. Studies with incomplete or unavailable results or with duplicate information were excluded. Data were selected by two independent investigators and analyzed using R software, a metapackage that generated the forest plots [95% confidence interval (CI)]. Heterogeneity was assessed using the I² statistic, and funnel plot asymmetry was assessed using Egger's test. Countries were compared using an HDI cutoff ≥0.8. Methodological quality was assessed using Joanna Briggs Institute (JBI) criteria. The overall prevalence of HTLV-1 infection was 0.91% (95% CI: 0.80-1.02, p < .0001) and was higher in low HDI countries [1.18% (95% CI: 1.03-1.34)] than in high HDI countries [0.41% (95% CI: 0.27-0.57)]. Prevalence varied according to the populations studied: it was higher in the general population [1.65% (95% CI: 1.08-2.34)] compared to pregnant women [0.34% (95% CI: 0.17-0.57)] and blood donors [0.04% (95% CI: 0.01-0.08)]. Consistently, prevalence for each population group was higher in low HDI countries than in high HDI countries. The worldwide prevalence of HTLV-1 infection is highly heterogeneous, with a global prevalence of 0.91%. In high HDI countries, the observed prevalence is approximately three times lower than in low HDI countries. In the general population, the observed prevalence is about 5 times higher than in pregnant women and 41 times higher than in blood donors.

Chitotriosidase 1 in the cerebrospinal fluid as a putative biomarker for HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) progression

Human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an inflammatory neurodegenerative disease that affects motor, urinary, intestinal, and sensory functions. Typically, HAM/TSP is slowly progressive, but it may vary from limited motor disability after decades (very slow progression) to loss of motor function in a few years from disease onset (rapid). In this study, we aimed to identify prognostic biomarkers for HAM/TSP to support patient management. Thus, proteomic analysis of the cerebrospinal fluid (CSF) was performed with samples from HTLV-1 asymptomatic carriers (AC) (n=13) and HAM/TSP patients (n=21) with rapid, typical, and very slow progression using quantitative label-free liquid chromatography/tandem mass spectrometry. Enrichment analyses were also carried out to identify key biological processes associated with distinct neurological conditions in HTLV-1 infection. Candidate biomarkers were validated by ELISA in paired CSF and serum samples, and samples from HTLV-1-seronegative individuals (n=9) were used as controls. CSF analysis identified 602 proteins. Leukocyte/cell activation, immune response processes and neurodegeneration pathways were enriched in rapid progressors. Conversely, HTLV-1 AC and HAM/TSP patients with typical and very slow progression had enriched processes for nervous system development. Differential expression analysis showed that soluble vascular cell adhesion molecule 1 (sVCAM-1), chitotriosidase 1 (CHIT1), and cathepsin C (CTSC) were upregulated in HAM/TSP. However, only CHIT1 was significantly elevated after validation, particularly in HAM/TSP rapid progressors. In contrast, none of these biomarkers were altered in serum. Additionally, CSF CHIT1 levels in HAM/TSP patients positively correlated with the speed of HAM/TSP progression, defined as points in the IPEC-2 HAM/TSP disability scale per year of disease, and with CSF levels of phosphorylated neurofilament heavy chain, neopterin, CXCL5, CXCL10, and CXCL11. In conclusion, higher CSF levels of CHIT1 were associated with HAM/TSP rapid progression and correlated with other biomarkers of neuroinflammation and neurodegeneration. Therefore, we propose CHIT1 as an additional or alternative CSF biomarker to identify HAM/TSP patients with a worse prognosis.

Clinical and Public Health Implications of Human T-Lymphotropic Virus Type 1 Infection

Human T-lymphotropic virus type 1 (HTLV-1) is estimated to affect 5 to 10 million people globally and can cause severe and potentially fatal disease, including adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The burden of HTLV-1 infection appears to be geographically concentrated, with high prevalence in discrete regions and populations. While most high-income countries have introduced HTLV-1 screening of blood donations, few other public health measures have been implemented to prevent infection or its consequences. Recent advocacy from concerned researchers, clinicians, and community members has emphasized the potential for improved prevention and management of HTLV-1 infection. Despite all that has been learned in the 4 decades following the discovery of HTLV-1, gaps in knowledge across clinical and public health aspects persist, impeding optimal control and prevention, as well as the development of policies and guidelines. Awareness of HTLV-1 among health care providers, communities, and affected individuals remains limited, even in countries of endemicity. This review provides a comprehensive overview on HTLV-1 epidemiology and on clinical and public health and highlights key areas for further research and collaboration to advance the health of people with and at risk of HTLV-1 infection.

Prevalence of human T-lymphotropic virus type 1 and 2 (HTLV-1/-2) infection in pregnant women in Brazil: a systematic review and meta-analysis

Human T-lymphotropic virus type 1 (HTLV-1) infection may cause serious disease, while pathogenicity of HTLV-2 is less certain. There are no screening or surveillance programs for HTLV-1/-2 infection in Brazil. By performing this systematic review, we aimed to estimate the prevalence of HTLV-1/-2 infections in pregnant women in Brazil. This review included cohort and cross-sectional studies that assessed the presence of either HTLV-1/-2 infection in pregnant women in Brazil. We searched BVS/LILACS, Cochrane Library/CENTRAL, EMBASE, PubMed/MEDLINE, Scopus, Web of Science and gray literature from inception to August 2020. We identified 246 records in total. Twenty-six of those were included in the qualitative synthesis, while 17 of them were included in the meta-analysis. The prevalence of HTLV-1 in Brazilian pregnant women, as diagnosed by a positive screening test and a subsequent positive confirmatory test, was 0.32% (95% CI 0.19-1.54), while of HTLV-2 was 0.04% (95% CI 0.02-0.08). Subgroup analysis by region showed the highest prevalence in the Northeast region (0.60%; 95% CI 0.37-0.97) for HTLV-1 and in the South region (0.16%; 95% CI 0.02-1.10) for HTLV-2. The prevalence of HTLV-1 is much higher than HTLV-2 infection in pregnant Brazilian women with important differences between regions. The prevalence of both HTLV-1/-2 are higher in the Northeast compared to Center-West region.

High proviral load of human T cell lymphotropic virus type-1 facilitates coronary artery diseases

Objective(s):

Coronary artery disease (CAD) is known as a life threatening disease, worldwide. In this study the role of HTLV-1 infection was evaluated on cardiac involvement in an endemic region of northeastern Iran.

Materials and Methods:

Serologic and molecular tests for HTLV-1 infection were carried out in subjects who had coronary angiography. A real-time PCR, TaqMan method, to quantify HTLV-1 proviral load (PVL), and routine hematological and biochemical tests were performed for study subjects.

Results:

Twenty nine patients were HTLV-1+CAD+ and 13 cases were HTLV-1+CAD-. Although, there were no significant differences for risk factors like FBS, HDL, triglyceride, systolic and diastolic blood pressure (Cbp, Dbp), waist circumference (WC), hip circumference (WL), cholesterol (P=0.003), and LDL (P=0.007) levels, and monocyte count (P=0.05) had meaningful differences. The mean HTLV-1 PVL in HTLV-1+CAD+ subjects was 992.62±120 which was higher compared with HTLV-1+CAD- group (406.54±302 copies/104 PBMCs). Moreover, HTLV-1 PVL in males (833±108) was lower compared with females (1218±141 copies/104 PBMCs) (P=0.05). Patients with HTLV-1-PVL of more than 500 copies/104 had more diffused atherosclerosis plaque than patients with less than 500 (OR=6.87, 95% CI=1.34-35.05; P=0.016). Furthermore, patients with diffused coronary atherosclerosis had significantly higher levels of HTLV-1 PVL than patients with middle, proximal, and normal location of coronary sclerotic lesions (P<0.05).

Conclusion:

Taken together, in endemic area, HTLV-1 infection, more likely is a facilitating factor for heart complications and the high HTLV-1 PVL might affect CAD manifestations.

Hospital admissions in individuals with HTLV-1 infection in Spain

OBJECTIVE

To examine the clinical burden and disease spectrum, as well as time trends for human T-cell leukemia virus type 1 (HTLV-1) and HTLV type 2 (HTLV-2) hospital admissions.

DESIGN

Retrospective, observational study using the Spanish National Hospital Discharge Database.

METHODS

Information for the diagnostic codes HTLV-1 and HTLV-2 using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) was retrieved from the national public registry since 1997--2015.

RESULTS

From a total of 66 462 136 nationwide hospital admissions recorded during the study period, 135 included HTLV diagnosis, being HTLV-1 in 115 (85.2%) and HTLV-2 in 20 (14.8%). The overall hospital admission rate because of HTLV was 2.03 per million, without significant yearly changes. First admissions represented 104 (77%) whereas 31 (23%) were re-admissions. The median in-hospital stay for HTLV patients was 9 days. In-hospital death occurred in 11 (8.1%). The median age of individuals with HTLV admission was 48 years and 60 (44.4%) were women. HTLV was recorded as the main diagnosis in 20%. The most frequent clinical conditions recorded alongside HTLV diagnosis were myelopathy (61; 45.2%), leukemia/lymphoma (30; 22.2%), solid organ transplantation (14; 10.4%) and child delivery (7; 5.2%).

CONCLUSION

The rate of HTLV diagnosis in hospitalized patients in Spain is low, roughly of two per million admissions. Despite continuous large immigrant flows from HTLV-1 endemic areas, no significant rising in hospitalizations because of HTLV-1 associated illnesses were noticed during the last two decades. Classical clinical complications of HTLV-1 infection, such as myelopathy and lymphoma account for more than two-thirds of cases.

An insight to HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) pathogenesis; evidence from high-throughput data integration and meta-analysis

BACKGROUND

Human T-lymphotropic virus 1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a progressive disease of the central nervous system that significantly affected spinal cord, nevertheless, the pathogenesis pathway and reliable biomarkers have not been well determined. This study aimed to employ high throughput meta-analysis to find major genes that are possibly involved in the pathogenesis of HAM/TSP.

RESULTS

High-throughput statistical analyses identified 832, 49, and 22 differentially expressed genes for normal vs. ACs, normal vs. HAM/TSP, and ACs vs. HAM/TSP groups, respectively. The protein-protein interactions between DEGs were identified in STRING and further network analyses highlighted 24 and 6 hub genes for normal vs. HAM/TSP and ACs vs. HAM/TSP groups, respectively. Moreover, four biologically meaningful modules including 251 genes were identified for normal vs. ACs. Biological network analyses indicated the involvement of hub genes in many vital pathways like JAK-STAT signaling pathway, interferon, Interleukins, and immune pathways in the normal vs. HAM/TSP group and Metabolism of RNA, Viral mRNA Translation, Human T cell leukemia virus 1 infection, and Cell cycle in the normal vs. ACs group. Moreover, three major genes including STAT1, TAP1, and PSMB8 were identified by network analysis. Real-time PCR revealed the meaningful down-regulation of STAT1 in HAM/TSP samples than AC and normal samples (P = 0.01 and P = 0.02, respectively), up-regulation of PSMB8 in HAM/TSP samples than AC and normal samples (P = 0.04 and P = 0.01, respectively), and down-regulation of TAP1 in HAM/TSP samples than those in AC and normal samples (P = 0.008 and P = 0.02, respectively). No significant difference was found among three groups in terms of the percentage of T helper and cytotoxic T lymphocytes (P = 0.55 and P = 0.12).

CONCLUSIONS

High-throughput data integration disclosed novel hub genes involved in important pathways in virus infection and immune systems. The comprehensive studies are needed to improve our knowledge about the pathogenesis pathways and also biomarkers of complex diseases.

HTLV-1 infection: An emerging risk. Pathogenesis, epidemiology, diagnosis and associated diseases

The Human T-Lymphotropic Virus type 1 (HTLV-1) affects up to 10 million people worldwide. It is directly associated to one of the most aggressive T cell malignancies: Adult T Cell Leukemia-Lymphoma (ATLL) and a progressive neurological disorder, Tropical Spastic Paraparesis/ HTLV-1 Associated Myelopathy (TSP/HAM). Also, infected patients tend to have more severe forms of infectious diseases such as Strongyloidiasis and Tuberculosis. HTLV spreads through parenteral, sexual, and vertical (mother-to-child) routes. Effective viral transmission is produced mainly by cell to cell mechanism, unlike other retroviruses such as HIV, which usually spread infecting cells in a cell-free form. HTLV also has a peculiar distribution, with clusters of high endemicity in nearby areas of very low prevalence or absence of the virus. This could be explained by factors including a possible founder effect, the predominance of mother to child transmission and the cell-to-cell trans-mission mechanisms. More data on viral epidemiology are needed in order to develop strategies in endemic areas aimed at reducing viral dissemination. In this review, we critically analyze HTLV-1 pathogenesis, epidemiology, diagnosis, associated diseases, preventive strategies, and treatments, with emphasis to the emerging risk for Europe and particularly Spain, focusing on prevention methods to avoid viral transmission and associated diseases.

High CD8 T cell percentage and HCV replication control are common features in HIV-1 controllers and HTLV-2-co-infected patients with a history of injection drug use

HTLV-2/HIV-1-coinfected patients and HIV-infected patients with natural HIV-1 control show an immune capacity that allows some control of viral infections. These two groups of patients have showed an immune capacity that allows them to have some control over viral infections, very strong control of HIV-1 replication in the case of HIV-1 controllers. The purpose of this retrospective cross-sectional study was to compare viral and immunologic parameters between three cohorts of Caucasian adult HIV-1-infected patients, including HIV-1 controllers (29 patients), HTLV-2/HIV-1 chronic progressors (56 patients), and HIV-1 chronic progressors (101 patients), followed in two different tertiary University Hospitals in Spain. Demographic parameters, nadir CD4 T cell count, CD4 and CD8 T cell counts and percentage, anti-HCV antibodies, HCV RNA load, HCV genotype, HIV-1 RNA loads, and anti-HTLV-2 antibodies were analyzed. HIV-1 controllers and HTLV-2/HIV-1 chronic progressors were younger and with shorter time since HIV-1 diagnosis compared to HIV-1 chronic progressors. HIV-1 controllers and HTLV-2/HIV-1 chronic progressors had significantly higher CD8 T cell percentage (p = 0.002 and p = 0.016, respectively) and lower levels of HCV RNA loads (0.015 and 0.007, respectively) compared to that of HIV-1 chronic progressors. Multivariate analyses showed that gender and HTLV-2 infection were independently associated to HCV RNA load, while only HTLV-2 infection was independently associated to CD8 T cell percentage. The implication of HTLV-2 infection in the control of HIV-1 and HCV infections is worth being further analyze.

From hidden outbreaks to epidemic emergencies: the threat associated with neglecting emerging pathogens

Not all infectious disease outbreaks undergo full epidemiological investigations. In certain situations, the resultant lack of knowledge has led to the development of epidemics and public health emergencies. This review will examine six emerging pathogens including their history, present status, and potential to expand to epidemics. Recommendations to improve our understanding of these hidden outbreaks and others also will be provided in the context of health systems policy.

Human T-lymphotropic virus type 1 infection and disease in Spain

: Human T-lymphotropic virus type 1 (HTLV-1) infection is a neglected disease despite roughly 15 million people are chronically infected worldwide. Lifelong less than 10% of carriers develop life-threatening diseases, mostly a subacute myelopathy known as tropical spastic paraparesis (TSP) and a lymphoproliferative disorder named adult T-cell leukemia (ATL). HTLV-1 is efficiently transmitted perinatally (breastfeeding), sexually (more from men to women) and parenterally (transfusions, injection drug user (IDU), and transplants). To date there is neither prophylactic vaccine nor effective antiviral therapy. A total of 327 cases of HTLV-1 infection had been reported at the HTLV-1 Spanish registry until December 2016, of whom 34 had been diagnosed with TSP and 25 with ATL. Overall 62% were Latin American immigrants and 13% were persons of African origin. The incidence of HTLV-1 in Spain has remained stable for nearly a decade with 20-25 new cases yearly. Of the 21 newly diagnosed HTLV-1 cases during year 2016, one was a native Spaniard pregnant woman, and four presented with symptomatic disease, including three with ATL and one with TSP. Underdiagnosis of HTLV-1 in Spain must be high (iceberg model), which may account for the disproportionate high rate of symptomatic cases (almost 20%) and the late recognition of preventable HTLV-1 transmissions in special populations, such as newborns and transplant recipients. Our current estimate is of 10 000 persons living with HTLV-1 infection in Spain. Given the large flux of immigrants and visitors from HTLV-1 endemic regions to Spain, the expansion of HTLV-1 screening policies is warranted. At this time, it seems worth recommending HTLV testing to all donor/recipient organ transplants and pregnant women regardless place of birth. Although current leukoreduction procedures largely prevent HTLV-1 transmission by blood transfusions, HTLV testing of all first-time donors should be cost-effective contributing to unveil asymptomatic unaware HTLV-1 carriers.

Assessment of HTLV-1 proviral load, LAT, BIM, c-FOS and RAD51 gene expression in adult T cell leukemia/lymphoma

Adult T cell leukemia/lymphoma (ATLL) is a life-threatening malignancy of HTLV-1 infected Th lymphocytes. In the present study host-virus interactions were investigated by assessment of HTLV-1 proviral load (PVL) and host gene expression. A cross-sectional study was carried out on 18 ATLL, 10 HAM/TSP patients and 18 HTLV-1 asymptomatic carriers (ACs). DNA and mRNA of the peripheral blood mononuclear cells were extracted for PVL and LAT, BIM, c-FOS and RAD51 gene expression measurement using qRT-PCR. The mean PVL in ATLL patients was 11,430 ± 3770 copies/10⁴ which was statistically higher than ACs, 530 ± 119 copies/10⁴, (p < 0.001). The expression of BIM, and c-FOS in ATLL patients were higher than HTLV-1 ACs; however, there were no statistically significant differences. The expression of RAD51 as an essential player on DNA repair showed around 160 times increase in ATLL group (166 ± 95) compared to ACs (1.04 ± 0.34) which is statistically significant (p < 0.001). Interestingly, there was a positive correlation between RAD51 expression and HTLV-PVL. The expression of LAT as a central adaptor in TCR signaling interestingly was around 36 times higher in ATLL group than ACs (ATLL; 41.33 ± 19.91 vs. ACs; 1.15 ± 0.22, p < 0.001). This finding showed that TCR signaling pathway mainly provides the growth factors for transformed cells. Furthermore, the overexpression of RAD51 which has been induced in HTLV-1 infected cells as a consequence of virus replication is not able to overcome the DNA damage toward cell transformation.

HTLV infection in HCV-antibody positive patients in Spain

Since hepatitis C virus (HCV) and human T-lymphotropic virus (HTLV) share transmission routes, dual infection could be frequent. In Spain, HTLV underdiagnosis is highlighted by the high proportion of patients presenting either with tropical spastic paraparesis (TSP) or adult T-cell leukemia (ATL) at first diagnosis. We examined whether the renewed efforts for expanding HCV testing may provide a sentinel population that might selectively be targeted to unveil asymptomatic HTLV carriers. The presence of anti-HTLV antibodies was examined in 3,838 consecutive individuals with reactive HCV serology attended during the last three years at 13 hospitals distributed across the Spanish geography. Overall 71% were male and the median age was 41-years old. Foreigners represented 9% of the study population. A total of 50 individuals (1.3%) were seroreactive for HTLV, being 30 confirmed as HTLV-2 and two as HTLV-1 (0.12%). The remaining 18 had indeterminate Western blot patterns. Most individuals with HTLV-2 and HTLV indeterminate serology were HIV-positive, former injection drug users and native Spaniards. In contrast, the two HTLV-1 infections were found in men coming from Brazil and the Dominican Republic, respectively. In summary, the overall prevalence of HTLV infection in individuals living in Spain seropositive for HCV is 1.3%, more than 10-fold greater than in general outclinics in Spain. However, immigrants from HTLV-1 endemic regions and former injection drug users with HTLV-2 infection are by far the major contributory groups in HCV patients. Therefore, testing for HTLV in newly diagnosed HCV individuals would not contribute much to improve late HTLV diagnosis in Spain.

Evaluation of T Regulatory Lymphocytes Transcription Factors in HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) Patients

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is an aggressive neurological disease. The CD4⁺CD25⁺ T cell population plays pivotal roles in the maintenance of immunological tolerance and prevention of such autoimmune diseases. In the current study, proviral load (PVL), factor forkhead box p3 (Foxp3), and glucocorticoid-induced tumor necrosis factor receptor-related protein (GITR) gene expression and regulatory T cells (Tregs) counts of 21 HAM/TSP patients and 16 HTLV-1 healthy carriers (ACs) were measured using real-time PCR, TaqMan method, and flow cytometry. The demographic, history of disease, and severity of myelopathy were assessed by a checklist and the Osame motor disability score (OMDS). The mean OMDS for HAM/TSP was 4.82 ± 2.37 which had no significant correlation with Treg count or the expression of Foxp3, GITR, and PVL. The CD4⁺CD25⁺ cell counts had no significant differences between HAM/TSP and ACs. Findings revealed a higher PVL in HAM/TSPs (313.36 copies/10⁴) compared to ACs (144.93 copies/10⁴, p = 0.035). The Foxp3 and GITR mRNA levels were lower in HAM/TSP patients (11.78 and 13.80, respectively) than those in healthy carriers (18.44 and 21.00, p = 0.041 and 0.03, respectively). There was a significant correlation between Treg frequency and Foxp3 gene expression (R = 0.67, p = 0.006) and GITR and Foxp3 (R = 0.84, p = 0.042) in HAM/TSP patients. Furthermore, the transcription factors have strong correlations with CD4⁺CD25⁺ T cell frequencies. These findings suggest that HTLV-1 infection can modify the expression of main functional transcription factors, FOXP3 and GITR, which may lead to immune response deterioration of Tregs and consequently HAM/TSP manifestation.

Current views on interferon therapy for HIV

INTRODUCTION

Knowledge of IFN-antiviral activity against HIV infection dates from the first years of the AIDS epidemic. Recombinant IFN had an inhibitory effect on HIV and was not toxic to peripheral blood mononuclear cells (PBMC), and this finding was the basis for the design of clinical trials that evaluated the potential role of IFN-alpha as an inhibitor of HIV replication.

AREAS COVERED

This review summarizes the history of IFN-alpha in the treatment of HIV infection with reviews of studies performed in different clinical settings; in the pre-highly active antiretroviral therapy (HAART) era, as part of a structured treatment interruption (STI) strategy, in acute HIV infection, as part of salvage therapy, and eliminating the HIV reservoir.

EXPERT OPINION

The role of IFN-alpha has been dismissed in the area of HIV therapy. For this reason, with the advent of HAART, which substantially reduced mortality and the appearance of AIDS, IFN-alpha ceased to be used as an antiretroviral agent in different strategies. In contrast, because of the promising results achieved with IFN-alpha therapy in eliminating the HIV viral reservoir, this may constitute the main research field for IFN-alpha in the HIV setting.

Serological study of Trypanosoma cruzi, Strongyloides stercoralis, HIV, human T cell lymphotropic virus (HTLV) and syphilis infections in asymptomatic Latin-American immigrants in Spain

OBJECTIVE

We aimed to perform a serological screening for T. cruzi, Strongyloides stercoralis, HIV, human T cell lymphotropic virus (HTLV) and syphilis in Latin American immigrants admitted to hospital in Spain.

METHODS

We have carried out a cross-sectional study of Latin American immigrants admitted to the Hospital General Universitario Alicante (Spain) from June 2012 to May 2014, where screening of Chagas disease, strongyloidiasis, HTLV, HIV and syphilis was performed by serology.

RESULTS

A total 180 patients were included in the study. Patients' median age was 38 years old, 123 (68.3%; 123/180) were female and 57 (31.7%; 57/180) male. Five of the 180 (2.5%) patients were positive for Chagas disease; associated with knowledge about Chagas disease (p=0.005), previous contact with patients with Chagas disease (p=0.04) and being Bolivian (p<0.001). Forty-two of the 157 (26.8%) patients were positive for Strongyloides serology; associated positively with being male (p<0.001), eosinophilia (p=0.001), hyper-IgE (p<0.001) and being Ecuadorian (p=0.001), and negatively associated with being Colombian (p=0.03). Positive serology of latent syphilis was found in 1.8% (3/171) of patients. Serology of HTLV was negative in all cases. No new cases of HIV infection were diagnosed.

CONCLUSIONS

We propose that Latin American immigrant patients admitted to hospital in Spain be screened for strongyloidiasis, Chagas disease and syphilis by serology.

Prevalence and phylogenetic analysis of HTLV-1 in a segregated population in Iran

Human T-lymphotropic virus type 1 (HTLV-1) infection is an important health issue that affects a variety of endemic areas. The Khorasan province, mainly its capital Mashhad in northeastern Iran, was reported to be as one of these endemic regions. Torbat-e Heydarieh, a large city Southwest border to Mashhad with a segregated population was investigated for the prevalence and associated risk factors of HTLV-1 infection in 400 randomly selected individuals. Blood samples were tested for the presence of HTLV-1 antibodies via the ELISA method and then were confirmed by an Immunoblot test. For the presence of HTLV-1 in lymphocytes of infected subjects, PCR was performed on LTR and TAX regions. DNA sequencing of LTR fragment was also carried out to determine the phylogenetic of HTLV-1, using the Maximum likelihood method. HTLV-1 sero-reactivity (sero-prevalence) among the study population was 2% (8/400), of which 1.25% had HTLV-1 provirus in lymphocytes (actual prevalence). HTLV-1 infection was significantly associated with the age, marital status, and history of blood transfusion (P < 0.05). However, there were no statistical differences between HTLV-1 infection, and gender, surgery, and hospitalization. In regression analysis, age showed the most significant correlation with the infection (P = 0.006, OR = 4.33). Based on our phylogenetic study, the HTLV-1 prevalent sequence type of Torbat-e Heydarieh belongs to the cosmopolitan subtype A. HTLV-1 prevalence in Torbat-e Heydarieh (1.25%) is low comparing to those of both Mashhad (2-3%) and Neishabour (3.5-5%) in the province of Khorasan. Thus, traveling mobility and population mixing such as marriage, bureaucratic affairs, occupation, and economic activities could be the usual routs of HTLV-1 new wave of spreading in this segregated city.

Triple Therapy with Prednisolone, Pegylated Interferon and Sodium Valproate Improves Clinical Outcome and Reduces Human T-Cell Leukemia Virus Type 1 (HTLV-1) Proviral Load, Tax and HBZ mRNA Expression in Patients with HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis

Considering that there is no effective treatment for human T-cell leukemia virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis, this study aimed to assess the impact of triple combination therapy-interferon-α, valproic acid, and prednisolone-on clinical outcomes, main HTLV-1 viral factors, and host anti-HTLV-1 antibody response. HTLV-1 proviral load (PVL), and HBZ and Tax mRNA expression levels were measured in peripheral blood mononuclear cells of 13 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis before and after treatment with 180 μg pegylated interferon once a week, 10-20 mg/kg/day sodium valproate, and 5 mg/day prednisolone for 25 weeks using a TaqMan real-time polymerase chain reaction assay. Furthermore, anti-HTLV-1 titer, Osame Motor Disability Score, Ashworth spasticity scale, and urinary symptoms (through standard questionnaire and clinical monitoring) were assessed in patients before and after the treatment. HTLV-1 PVL and HBZ expression significantly decreased after the treatment [PVL from 1443 ± 282 to 660 ± 137 copies/10(4) peripheral blood mononuclear cells (p = 0.01); and HBZ from 8.0 ± 1.5 to 3.0 ± 0.66 (p < 0.01)]. Tax mRNA expression decreased after the treatment from 2.26 ± 0.45 to 1.44 ± 0.64, but this reduction was not statistically significant (p = 0.10). Furthermore, anti-HTLV-1 titer reduced dramatically after the treatment, from 3123 ± 395 to 815 ± 239 (p < 0.01). Clinical signs and symptoms, according to Osame Motor Disability Score and Ashworth score, improved significantly (both p < 0.01). Urinary symptoms and sensory disturbances with lower back pain were reduced, though not to a statistically significant degree. Although signs and symptoms of spasticity were improved, frequent urination and urinary incontinence were not significantly affected by the triple therapy. The results provide new insight into the complicated conditions underlying HTLV-1-associated diseases.

Hispano-Americans in Europe: what do we know about their health status and determinants? A scoping review

Background

Policy makers and health practitioners are in need of guidance to respond to the growing geographic mobility of Hispano-American migrants in Europe. Drawing from contributions from epidemiology, social sciences, demography, psychology, psychiatry and economy, this scoping review provides an up-to-date and comprehensive synthesis of studies addressing the health status and determinants of this population. We describe major research gaps and suggest specific avenues of further inquiry.

Methods

We identified systematically papers that addressed the concepts “health” and “Hispano Americans” indexed in five data bases from Jan 1990 to May 2014 with no language restrictions. We screened the 4,464 citations retrieved against exclusion criteria and classified 193 selected references in 12 thematic folders with the aid of the reference management software ENDNOTE X6. After reviewing the full text of all papers we extracted relevant data systematically into a table template to facilitate the synthesising process.

Results

Most studies focused on a particular disease, leaving unexplored the interlinkages between different health conditions and how these relate to legislative, health services, environmental, occupational, and other health determinants. We elucidated some consistent results but there were many heterogeneous findings and several popular beliefs were not fully supported by empirical evidence. Few studies adopted a trans-national perspective and many consisted of cross-sectional descriptions that considered “Hispano-Americans” as a homogeneous category, limiting our analysis. Our results are also constrained by the availability and varying quality of studies reviewed.

Conclusions

Burgeoning research has produced some consistent findings but there are huge gaps in knowledge. To prevent unhelpful generalisations we need a more holistic and nuanced understanding of how mobility, ethnicity, income, gender, legislative status, employment status, working conditions, neighbourhood characteristics and social status intersect with demographic variables and policy contexts to influence the health of the diverse Hispano-American populations present in Europe.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1799-x) contains supplementary material, which is available to authorized users.

Delayed liver fibrosis in HTLV-2-infected patients co-infected with HIV-1 and hepatitis C virus with suppressive antiretroviral therapy

OBJECTIVES

The absence of direct clinical symptoms clearly associated to HTLV-2 infection may partially explain an underestimate of the real HTLV-2 prevalence rate and its effects in patients concurrently infected with HIV-1 and hepatitis C virus (HCV). Hence, to date, the influence of HTLV-2 on hepatic fibrosis has been poorly studied.

DESIGN

Retrospective study to clarify the influence of HTLV-2 infection in HCV infection and hepatic fibrosis among patients co-infected with HIV-1.

METHODS

This is a comparative cohort study including 39 HTLV-2-HIV-1-HCV co-infected patients and 42 HIV-1-HCV co-infected patients conducted in a tertiary care hospital. They were evaluated for transaminase levels, hepatic fibrosis stage, interleukin (IL)-28B genotype, Th1/Th2/Th17 cytokine levels, immune activation, inflammation, and microbial translocation.

RESULTS

HTLV-2-HIV-1-HCV co-infected patients had lower alanine aminotransferase levels (P = 0.023) and hepatic fibrosis (P = 0.012), compared to HIV-1-HCV co-infected patients. Moreover, Kaplan-Meier survival analysis showed a delay in hepatic fibrosis development for up to 5 years (P = 0.032). HTLV-2-HIV-1-HCV co-infected patients also had higher Th1/Th2 ratio (interferon γ/IL-4 ratio, P = 0.043; tumor necrosis factor α/IL-4 ratio, P = 0.010) and Th17 response (P = 0.015), whereas lower CD8 T-cell activation (P = 0.017) and lipopolysaccharide level (P = 0.001).

CONCLUSION

Findings strongly support that HTLV-2 co-infection might delay fibrosis development in HCV-HIV-1 co-infected patients.

Cyclosporine for the treatment of HLTV-1-induced HAM/TSP: an experience from a case report

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) remains a challenging disease. Treatment options are scarce, and their safety and efficacy are currently a matter of concern.We present a case report describing our experience using cyclosporine in a patient with early HAM/TSP who started with a gait disturbance at Vall d'Hebron University Hospital (Barcelona) from August 2012 to October 2013. After 62 weeks of treatment, clinical improvement was observed and proviral load diminished. No safety concerns were observed.Cyclosporine seems to be effective in new-onset HAM/TSP or in chronic HAM/TSP that develops a relapse. However, the duration and safety profile of this steroid-sparing therapy remain unknown and should be further investigated.

Molecular epidemiology and clinical features of human T cell lymphotropic virus type 1 infection in Spain

Human T cell lymphotropic virus type 1 (HTLV-1) infection in Spain is rare and mainly affects immigrants from endemic regions and native Spaniards with a prior history of sexual intercourse with persons from endemic countries. Herein, we report the main clinical and virological features of cases reported in Spain. All individuals with HTLV-1 infection recorded at the national registry since 1989 were examined. Phylogenetic analysis was performed based on the long terminal repeat (LTR) region. A total of 229 HTLV-1 cases had been reported up to December 2012. The mean age was 41 years old and 61% were female. Their country of origin was Latin America in 59%, Africa in 15%, and Spain in 20%. Transmission had occurred following sexual contact in 41%, parenteral exposure in 12%, and vertically in 9%. HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) was diagnosed in 27 cases and adult T cell leukemia/lymphoma (ATLL) in 17 subjects. HTLV-1 subtype could be obtained for 45 patients; all but one belonged to the Cosmopolitan subtype a. One Nigerian pregnant woman harbored HTLV-1 subtype b. Within the Cosmopolitan subtype a, two individuals (from Bolivia and Peru, respectively) belonged to the Japanese subgroup B, another two (from Senegal and Mauritania) to the North African subgroup D, and 39 to the Transcontinental subgroup A. Of note, one divergent HTLV-1 strain from an Ethiopian branched off from all five known Cosmopolitan subtype 1a subgroups. Divergent HTLV-1 strains have been introduced and currently circulate in Spain. The relatively large proportion of symptomatic cases (19%) suggests that HTLV-1 infection is underdiagnosed in Spain.

Comparison of HTLV-I Proviral Load in Adult T Cell Leukemia/Lymphoma (ATL), HTLV-I-Associated Myelopathy (HAM-TSP) and Healthy Carriers

OBJECTIVE(S)

Human T Lymphocyte Virus Type one (HTLV-I) is a retrovirus that infects about 10-20 million people worldwide. Khorasan province in Iran is an endemic area. The majority of HTLV-I-infected individuals sustain healthy carriers but small proportion of infected population developed two progressive diseases: HAM/TSP and ATL. The proviral load could be a virological marker for disease monitoring, therefore in the present study HTLV-I proviral load has been evaluated in ATL and compared to HAM/TSP and healthy carriers.

MATERIALS AND METHODS

In this case series study, 47 HTLV-I infected individuals including 13 ATL, 23 HAM/TSP and 11 asymptomatic subjects were studied. Peripheral blood mononuclear cells (PBMCs) were investigated for presence of HTLV-I DNA provirus by PCR using LTR and Tax fragments. Then in infected subjects, HTLV-I proviral load was measured using real time PCR TaqMan method.

RESULTS

The average age of patients in ATL was 52±8, in HAM/TSP 45.52±15.17 and in carrier's 38.65±14.9 years which differences were not statistically significant. The analysis of data showed a significant difference in mean WBC among study groups (ATL vs HAM/TSP and carriers P=0.0001). Moreover, mean HTLV-I proviral load was 11967.2 ± 5078, 409 ± 71.3 and 373.6 ± 143.3 in ATL, HAM/TSP and Healthy Carriers, respectively. The highest HTLV-I proviral load was measured in ATL group that had a significant correlation with WBC count (R=0.495, P=0.001). The proviral load variations between study groups was strongly significant (ATL vs carrier P=0.0001; ATL vs HAM/TSP P= 0.0001 and HAM/TSP vs carriers P< 0.05). Conclusion : The present study demonstrated that HTLV-I proviral load was higher in ATL group in comparison with HAM/TSP and healthy carriers. Therefore, HTLV-I proviral load is a prognostic factor for development of HTLV-I associated diseases and can be used as a monitoring marker for the efficiency of therapeutic regime.

Human T Lymphotropic Virus Type I (HTLV-I) Oncogenesis: Molecular Aspects of Virus and Host Interactions in Pathogenesis of Adult T cell Leukemia/Lymphoma (ATL)

The study of tumor viruses paves the way for understanding the mechanisms of virus pathogenesis, including those involved in establishing infection and dissemination in the host tumor affecting immune-compromised patients. The processes ranging from viral infection to progressing malignancy are slow and usually insufficient for establishment of transformed cells that develop cancer in only a minority of infected subjects. Therefore, viral infection is usually not the only cause of cancer, and further environmental and host factors, may be implicated. HTLV-I, in particular, is considered as an oncovirus cause of lymphoproliferative disease such as adult T cell leukemia/lymphoma (ATL) and disturbs the immune responses which results in HTLV-I associated meylopathy/tropical spastic parapresis (HAM/TSP). HTLV-I infection causes ATL in a small proportion of infected subjects (2-5%) following a prolonged incubation period (15-30 years) despite a strong adaptive immune response against the virus. Overall, these conditions offer a prospect to study the molecular basis of tumorgenicity in mammalian cells. In this review, the oncogencity of HTLV-I is being considered as an oncovirus in context of ATL.

Epidemiological Aspects and World Distribution of HTLV-1 Infection

The human T-cell leukemia virus type 1 (HTLV-1), identified as the first human oncogenic retrovirus 30 years ago, is not an ubiquitous virus. HTLV-1 is present throughout the world, with clusters of high endemicity located often nearby areas where the virus is nearly absent. The main HTLV-1 highly endemic regions are the Southwestern part of Japan, sub-Saharan Africa and South America, the Caribbean area, and foci in Middle East and Australo-Melanesia. The origin of this puzzling geographical or rather ethnic repartition is probably linked to a founder effect in some groups with the persistence of a high viral transmission rate. Despite different socio-economic and cultural environments, the HTLV-1 prevalence increases gradually with age, especially among women in all highly endemic areas. The three modes of HTLV-1 transmission are mother to child, sexual transmission, and transmission with contaminated blood products. Twenty years ago, de Thé and Bomford estimated the total number of HTLV-1 carriers to be 10-20 millions people. At that time, large regions had not been investigated, few population-based studies were available and the assays used for HTLV-1 serology were not enough specific. Despite the fact that there is still a lot of data lacking in large areas of the world and that most of the HTLV-1 studies concern only blood donors, pregnant women, or different selected patients or high-risk groups, we shall try based on the most recent data, to revisit the world distribution and the estimates of the number of HTLV-1 infected persons. Our best estimates range from 5-10 millions HTLV-1 infected individuals. However, these results were based on only approximately 1.5 billion of individuals originating from known HTLV-1 endemic areas with reliable available epidemiological data. Correct estimates in other highly populated regions, such as China, India, the Maghreb, and East Africa, is currently not possible, thus, the current number of HTLV-1 carriers is very probably much higher.