No significant HTLV seroprevalence in German people who inject drugs.

BACKGROUND: Although human T-lymphotropic virus (HTLV) is transmitted via the same routes as human immunodeficiency virus (HIV), its worldwide seroprevalence differs drastically because HTLV is transmitted mainly via infected cells rather than free virus. The sharing of needles and other equipment places people who inject drugs (PWID) at particularly high-risk for such blood-borne diseases. METHODS: To validate the methodology used to process and analyze the dried blood spots (DBS) utilized in the study, dried serum spots (DSS) with dilutions of sera from known HTLV infected individuals were analyzed by ELISA and Western blot. DBS collected between 2011 and 2015 from 2,077 PWID in eight German cities recruited by respondent-driven sampling were tested for HTLV-specific antibodies. RESULTS: The validation demonstrated that the use of DSS allowed identification of samples with even low titers of HTLV-specific antibodies, although a confirmatory Western blot with an additional venous blood sample would often be required. Despite numerous HIV and HCV positive individuals being identified within the study population, none tested positive for HTLV. CONCLUSION: While the HIV and HCV prevalences in German PWID are comparable to those in other European countries, the very low prevalence of HTLV reflects the situation in the general population.

Flow cytometric-based protocols for assessing anti-MT-2 IgG1 reactivity: High-dimensional data handling to define predictors for clinical follow-up of Human T-cell Leukemia virus type-1 infection.

The present work provides an innovative methodological approach to assess the anti-HTLV-1 IgG1 reactivity with practical application in clinical laboratory. Serum from non-infected healthy controls (NI) and HTLV-1-infected patients, categorized as asymptomatic (AS), putatively progressing to HTLV-1 associated myelopathy/tropical spastic paraparesis - HAM/TSP (pHAM) or with clinical diagnosis of HAM/TSP (HT) were assayed in two-parallel flow cytometry platforms, referred as: Fix and Fix&Perm protocols. Operating-characteristics analysis indicated that a single pair of attributes ("serum dilution/cut-off") for Fix and Fix&Perm protocols presented excellent performance for the diagnosis of HTLV-1 infection. Conversely, Fix and Fix&Perm protocols displayed weak/moderate overall performances when applied with prognosis purposes of HTLV-1 infection. A panoramic snapshot provided by the reactivity boards revealed clearly the higher sensitivity of Fix&Perm protocol for detecting seropositivity for HT, suggesting that stepwise combinatory criteria would improve the global performance of using a single pair of attributes. Three data mining strategies were tested, including endpoint titer analysis, heatmap assemblage and decision tree analysis. Bi-dimensional heatmap analysis demonstrated that, while the clustering profile of NI vs HTLV-1+ revealed segregation in opposite poles, AS vs HT presented discrete segregation but still displaying an intertwined distribution pattern. The combination of methods for segregating AS from HT displayed a moderate but superior global accuracy (85.7%; LOOCV=71.4%). The comprehensive data analysis support that the combination of methods have improved the performance to the differential diagnosis of AS and HT, with direct association with laboratorial records, including serum cytokine levels and proviral load.

Prevalence of serological ineligibility among blood donors of a Hemotherapy Center in Caxias do Sul, southern Brazil

Introduction: Blood donation should be voluntary, anonymous and altruistic, and the donor should not, directly or indirectly, receive any remuneration or benefit by virtue of donating blood. Like any other therapeutic method, transfusion procedures are not risk free and can expose the patient to a several complications. Serological screening is of great importance to ensure transfusion safety. The present study aimed to estimate the prevalence of serological ineligibility among blood donors from a Hemotherapy Center in Caxias do Sul (RS). Method: An exploratory, descriptive and quantitative study was conducted on data from July 2010 to December 2015 collected at a Hemotherapy Center in Caxias do Sul (RS). Results: During the study period, 14,267 blood donors attended the Hemotherapy Center, of which 9,332 (65.40%) were males and 4,935 (34.60%) were female. Considering only the suitable donors, 12,702 blood donations were performed, 144 (1.13%) presented positive serological tests. The most prevalent positive serology was for hepatitis B (anti-HBc) with 98 cases (0.77%), followed by syphilis with 19 cases (0.15%); Chagas disease, with 10 (0.08%); hepatitis C, with nine (0.07%); and HIV and HTLV, with four (0.03%) reactive samples each. Conclusion: The results presented are important for health surveillance and make it possible to take measures to ensure safe blood stocks (AU)

[Relevance of safety measures to avoid HTLV transmission by transfusion in 2014]. / Pertinence des mesures sécuritaires transfusionnelles vis-à-vis du HTLV en 2014.

In high-income countries, the safety of blood transfusion related to viruses has reached a very high level, especially thanks to the implementation of multiple measures aimed at reducing the transfusion risk. The cost-effectiveness of these preventive measures is frequently discussed due to global financial resources, which are more and more limited. Hence, the revision of safety strategies is a key issue, especially when these strategies are redundant, as those implemented to avoid Human T-cell Lymphotropic Virus (HTLV) transmission, which are based on both antibodies screening and leucoreduction of blood products. The residual risk of the transmission of HTLV by transfusion has been recently estimated at 1 in 20 million donations (2010-2012) in France (excluding overseas territories). This estimation did not take into account the leucoreduction, which appears to be a very efficient preventive measure as the virus is strictly intra-cellular. To help decision-making, we have evaluated some parameters related to HTLV blood transmission. Firstly, the probability that an incident occurring during the leucoreduction process affects a HTLV-positive blood donation has been estimated at 1 in 178 million. Estimation of clinical consequences of HTLV-positive transfusions would affect 1 to 2 transfused-patients without leucoreduction, and one recipient every 192 years in case of 10% failures of the filtration method. Obviously, despite a risk, which appears to be controlled, HTLV screening will be disputed as soon as the efficiency of leucoreduction to totally prevent virus blood transmission will be proven and when pathogen inactivation methods are generalized to all blood cellular products.

Adult T-cell leukemia-lymphoma associated with follicular mucinosis.

Follicular mucinosis is frequently associated with follicular mycosis fungoides, but its association with adult T-cell leukemia-lymphoma (ATLL) is extremely rare. We report a case of a 50-year-old female patient with a history of ATLL, after multiple treatments, with residual/recurrent skin tumors in the forehead and legs. Biopsy of a skin tumor from the forehead revealed a perifollicular and intrafollicular atypical lymphoid infiltrate with abundant mucin deposition. Immunohistochemical stains showed that the atypical cells were positive for CD3, CD4, and CD25. Reverse transcription polymerase chain reaction performed on the tissue sections confirmed the presence of human T-cell leukemia virus in the biopsies of skin tumors. To our knowledge, this is only the third reported case of a follicular mucinosis in the setting of ATLL.

Human T-lymphotropic virus laboratory testing of maternal blood at time of cord blood donations and clinical implications.

BACKGROUND: In the United States, blood products are tested for infectious diseases including human T-lymphotropic virus (HTLV)-I/II. Positive results of maternal blood samples at the time of cord blood (CB) donation must be reported to mother and physician. Tests for HTLV have a high false-positive rate. This is problematic because there is no prenatal testing of the mother. STUDY DESIGN AND METHODS: This study involves 119,769 maternal blood samples at time of CB donation and evaluates positive results for HTLV in screening tests, supplemental immunoassays, and nucleic acid tests (NATs). Infectious disease markers (IDMs) and maternal health histories of HTLV-positive and -negative mothers were compared. RESULTS: Of 119,769 mothers donating CB, 545 tested positive with the screening test, 33 were positive with the supplemental tests, and two were positive with NAT. When indeterminate results were excluded from the supplemental test only six were positive. Eight of 34 mothers with positive or indeterminate supplemental test results had received intravenous immunoglobulin. There were no significant differences between HTLV-positive and -negative mothers with regard to the incidence of other IDMs. CONCLUSIONS: Testing maternal blood for HTLV is problematic for CB banks, obstetricians, and mothers because of the high false-positive rate. CB banks need rapid turnaround time and supplemental testing. If results on the latter are positive the obstetrician should be notified, educated, do follow-up testing, and counseling. Indeterminate results on supplemental tests are most likely false positives. We recommend that mothers with positive or indeterminate supplemental test results have follow-up NAT.

Infectious disease screening of blood specimens collected post-mortem provides comparable results to pre-mortem specimens.

Serology assays for standard screening are optimised for use with sera collected from living adults and children. Because of potential changes in the vascular compartments after death, methods used for screening sera from cadaveric organ donors need to be validated before testing these specimens. Serum was separated from blood collected from cadaveric donors within 24 h of death and biochemical parameters measured to detect dilution of protein and haemolysis. In order to demonstrate if any inhibitors that might interfere with the assays were present, pre and post-mortem specimens were spiked with aliquots of human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV), human T-cell Lymphotropic Virus (HTLV) and T. pallidum-positive sera. Comparison of serum from living subjects with serum obtained post-mortem showed that while the concentration of total protein decreased, concentrations of albumin, immunoglobulin G (IgG) and immunoglobulin M (IgM) remained unchanged. The degree of haemolysis, as measured by free haemoglobin, was within the limits accepted for the Architect analyser. Spiking of pre- and post-mortem specimens with aliquots of HIV, HCV, HBV, HTLV and T. pallidum-positive sera showed no statistical difference in the signal between pre-mortem and post-mortem results when tested on the Abbott Architect analyser. Positive results were obtained in each of a further nine subjects who had tested positive for HIV (n=1), HCV (n=8), HBV (n=1) on pre-mortem serological testing. These findings suggest that the sensitivity of the Abbott Architect serological screening tests is not significantly affected in specimens collected within 24 h of the cessation of life.

Neurological manifestations of coinfection with HIV and human T-lymphotropic virus type 1.

HIV-individuals are at risk for human T-lymphotropic virus (HTLV) coinfection and neurological diseases. Little is known about the impact of HAART among coinfected patients. In this study, 47 out of 428 HIV individuals were coinfected with HTLV (10.9%). Coinfection was an independent variable associated with neurological outcome (odds ratio 8.73). Coinfection was associated with myelopathy [chi square (X(2)) = 93, P < 0.001], peripheral neuropathy (X(2) = 6.5, P = 0.01), and hepatitis C virus infection (X(2) = 36.5, P < 0.001). HAART did not appear to protect against neurological diseases and had no impact on HTLV proviral load.

High prevalence of HTLV-I infection in Mashhad, Northeast Iran: a population-based seroepidemiology survey.

BACKGROUND: Mashhad, in the northeast of Iran has been suggested as an endemic area for human T cell lymphotropic virus type I (HTLV-I) infection since 1996. OBJECTIVES: We performed a community-based seroepidemiology study to examine the prevalence and risk factors for HTLV-I infection in the city of Mashhad. STUDY DESIGN: Between May and September 2009, overall 1678 subjects from all the 12 geographical area of Mashhad were selected randomly by multistage cluster sampling for HTLV antibody. The study population included 763 males and 915 females, with the mean age of 29.1 ± 18.5 years. 1654 serum samples were assessed for HTLV antibody using ELISA and reactive samples were confirmed by Western blot and PCR. RESULTS: The overall prevalence of HTLV-I infection in whole population was 2.12% (95% CI, 1.48-2.93) with no significant difference between males and females (p = 0.093) and the prevalence of HTLV-II seropositivity was 0.12% (95% CI, 0.02-0.44). The HTLV-I Infection was associated with age (p<0.001), marital status (p<0.001), education (p = 0.047), and history of blood transfusion (p = 0.009), surgery (p<0.001), traditional cupping (p = 0.002), and hospitalization (p = 0.004). In logistic regression analysis, age was the only variable that had a significant relation with the infection (p = 0.006, OR = 4.33). CONCLUSIONS: Our results demonstrated that Mashhad still remains an endemic area for HTLV-I infection despite routine blood screening. Thus, further strategies are needed for prevention of the virus transmission in whole population.

Risk of bronchioloalveolar carcinoma in patients with human T-cell lymphotropic virus type 1 (HTLV-I): case-control study results.

BACKGROUND: Human T-cell lymphotropic virus type 1 (HTLV-I) causes not only adult T-cell leukemia (ATL) but also HTLV-I associated T-cell bronchioloalveolitis, which is often chronic and subclinical. We have experienced eight HTVL-I carriers with bronchioloalveolar carcinoma, which is known to arise from bronchioloalveolar pneumocytes. This case-control study clarified the risk of bronchioloalveolar carcinoma in HTLV-I carriers. MATERIALS AND METHODS: During the past four years, 212 lung cancer patients were examined for serum anti-HTLV-I antibody. They underwent surgical treatment for lung cancer at Kumamoto University Hospital. Of these, 8 (4%) were HTLV-I carriers. As controls for this case-control study, we selected 24 HTLV-I negative-lung cancer patients (1:3 case-control ratio) matched for sex, age, and smoking status. The distributions of histological types of lung cancer were compared between the case (HTLV-I positive) and control (HTLV-I negative) groups. RESULTS: Histological types of the 8 HTLV-I carriers were bronchioloalveolar carcinoma in 6 patients and adenocarcinoma with bronchioloalveolar carcinoma component in 2. The prevalence of bronchioloalveolar carcinoma in HTLV-I carriers, 6 of 8 (75%), was significantly higher than the 6 of 24 (25%) in HTLV-I negative patients (p = 0.02). The prevalence of bronchioloalveolar carcinoma or adenocarcinoma with bronchioloalveolar carcinoma component in HTLV-I carriers, 8 of 8 (100%), was also significantly higher than the 13 of 24 (54%) in HTLV-I negative patients (p = 0.02). CONCLUSION: HTLV-I might be one risk of bronchioloalveolar carcinoma, probably because of inflammatory and/or immunologic responses involving bronchioloalveolar pneumocytes.

Current management of adult T-cell leukemia/lymphoma.

When oncologists diagnose patients suspected of lymphoid malignancy, it is important to consider the possibility of adult T-cell leukemia/lymphoma (ATL) with a routine check for serum human T-cell lymphotropic virus type 1 (HTLV-1) antibody. The following points are essential for the diagnosis of ATL: (1) cytologically or histologically proven peripheral T-cell malignancy, and (2) positivity for anti-HTLV-1 antibody. When a patient is diagnosed with ATL, it is important to make an accurate diagnosis of clinical subtype in order to make appropriate treatment decisions. For patients with smoldering or chronic type ATL, close observation with careful monitoring for opportunistic infections is recommended. For patients with the acute or lymphoma type requiring therapy, enrollment in a clinical trial is recommended. When there is no active trial or the patient is ineligible for a trial, we recommend intensive chemotherapy used for aggressive non-Hodgkin lymphoma such as the LSG15 regimen (VCAP-AMP-VECP) based on a recent phase III study. Because most patients with ATL are not curable with current chemotherapy regimens, it is reasonable to consider the applicability of allogeneic stem cell transplantation inpatients who show responses to chemotherapy. For relapsed or refractory patients, enrollment in a new-agent trial should be considered in addition to stem cell transplantation.

Seroprevalence and risk factors for human T cell lymphotropic virus type 1 and 2 infection in human immunodeficiency virus-infected patients attending AIDS referral center health units in Londrina and other communities in Paraná, Brazil.

The municipality of Londrina ranks second in the number of AIDS cases in the state of Paraná, Brazil, with the Ministry of Health notified of 1070 cases from 1984 to 2002. The aim of this study was to determine the seroprevalence and risk factors for HTLV-1/2 infection in HIV-infected patients attending the AIDS Reference Center serving Londrina (and surrounding region), Paraná, Brazil. Data concerning sociodemographic conditions and risk factors were collected from 784 HIV-infected patients, using a questionnaire. Blood samples were obtained from 758 of the patients and subjected to serologic screening tests for the determination of HTLV-1/2, as well as hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis. Most patients were white (mean age, 35.9 years); 55.9% were males and 44.1% were females. The most frequent sexually transmitted disease was gonorrhea (28.5%), followed by syphilis (14.3%) and condyloma (12.2%). The major risk factors associated with the acquisition of retroviruses were sexual contact (84.8%) and intravenous drug use (IDU, 11.9%). The overall infection seroprevalence was 6.4% for HTLV-1/2, 37.2% for HBV, 21.0% for HCV, and 24.4% for syphilis. HTLV-1 and HTLV-2 infections were confirmed in 0.8 and 4.9% of patients, respectively. HIV/HTLV-1/2 coinfection was more frequent in IDUs (59.2% of cases) and was strongly associated with HCV (22.60 [95% CI, 10.35-49.35]). A weak association with HBV (2.09 [95% CI, 1.13-3.90]) and no association with syphilis were observed. The results showed that human retroviruses are circulating in southern Brazil, mainly among white people of both genders of low socioeconomic conditions and educational level. Although the sexual route was considered to be the major risk factor for HIV infection, HTLV-1/2 infection was strongly associated with IDU.

Human T-cell lymphotropic virus antibody prevalence in HIV-1-infected individuals attending a sexual health clinic in South-East London.

Human immunodeficiency virus (HIV) and human T-cell lymphotropic virus (HTLV) are both retroviruses with similar routes of transmission. A number of reports suggest variable clinical outcomes in HIV and HTLV co-infected individuals. There is no published information regarding the prevalence of HIV and HTLV co-infection in the UK. We therefore carried out an unlinked anonymised retrospective study to investigate the prevalence of HTLV co-infection in HIV infected patients attending a sexual health clinic in South-East London. We identified sera from 777 HIV-1 positive adults (504 male, 273 female) who had attended our sexual health clinic between January 2000 and March 2001. Serum samples stored at -20 degrees C were initially tested by HTLV-1 and HTLV-2 antibody enzyme-linked immunoassay (EIA). An immunoblot assay was carried out on reactive samples to discriminate between viral subtypes. Samples with indeterminate results were also analyzed by Western blot. The prevalence of HTLV antibody was 0.8% (five patients with HTLV-1 and one with HTLV-2). Four of the HTLV-1 co-infected patients were females born abroad, of Black African or Caribbean origin. The other HTLV-1-infected patient was a male in the Black Other ethnic group born in the UK, demonstrating that transmission may occur outside recognized areas of high endemicity. The HTLV-2 co-infected individual was a White male born in Italy, and was likely to have been infected through intravenous drug use. The results suggest HTLV antibody screening should be considered in the local HIV infected population of south London.

Probability of viremia with HBV, HCV, HIV, and HTLV among tissue donors in the United States.

BACKGROUND: Tissue-banking organizations in the United States have introduced various review and testing procedures to reduce the risk of the transmission of viral infections from tissue grafts. We estimated the current probability of undetected viremia with hepatitis B virus (HBV), hepatitis C virus (HCV), human immunodeficiency virus (HIV), and human T-lymphotropic virus (HTLV) among tissue donors. METHODS: Rates of prevalence of hepatitis B surface antigen (HBsAg) and antibodies against HIV (anti-HIV), HCV (anti-HCV), and HTLV (anti-HTLV) were determined among 11,391 donors to five tissue banks in the United States. The data were compared with those of first-time blood donors in order to generate estimated incidence rates among tissue donors. The probability of viremia undetected by screening at the time of tissue donation was estimated on the basis of the incidence estimates and the window periods for these infections. RESULTS: The prevalence of confirmed positive tests among tissue donors was 0.093 percent for anti-HIV, 0.229 percent for HBsAg, 1.091 percent for anti-HCV, and 0.068 percent for anti-HTLV. The incidence rates were estimated to be 30.118, 18.325, 12.380, and 5.586 per 100,000 person-years, respectively. The estimated probability of viremia at the time of donation was 1 in 55,000, 1 in 34,000, 1 in 42,000, and 1 in 128,000, respectively. CONCLUSIONS: The prevalence rates of HBV, HCV, HIV, and HTLV infections are lower among tissue donors than in the general population. However, the estimated probability of undetected viremia at the time of tissue donation is higher among tissue donors than among first-time blood donors. The addition of nucleic acid-amplification testing to the screening of tissue donors should reduce the risk of these infections among recipients of donated tissues.

Immune responses to HTLV-I(ACH) during acute infection of pig-tailed macaques.

Human T cell lymphotropic virus type 1 (HTLV-I) is causally linked to adult T cell leukemia/lymphoma (ATL) and a chronic progressive neurological disease, HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). A nonhuman primate model that reproduces disease symptoms seen in HTLV-I-infected humans might facilitate identification of initial immune responses to the virus and an understanding of pathogenic mechanisms in HTLV-I-related disease. Previously, we showed that infection of pig-tailed macaques with HTLV-I(ACH) is associated with multiple signs of disease characteristic of both HAM/TSP and ATL. We report here that within the first few weeks after HTLV-I(ACH) infection of pig-tailed macaques, serum concentrations of interferon (IFN)-alpha increased and interleukin-12 decreased transiently, levels of nitric oxide were elevated, and activation of CD4(+) and CD8(+) lymphocytes and CD16(+) natural killer cells in peripheral blood were observed. HTLV-I(ACH) infection elicited virus-specific antibodies in all four animals within 4 to 6 weeks; however, Tax-specific lymphoproliferative responses were not detected until 25-29 weeks after infection in all four macaques. IFN-gamma production by peripheral blood cells stimulated with a Tax or Gag peptide was detected to varying degrees in all four animals by ELISPOT assay. Peripheral blood lymphocytes from one animal that developed only a marginal antigen-specific cellular response were unresponsive to mitogen stimulation during the last few weeks preceding its death from a rapidly progressive disease syndrome associated with HTLV-I(ACH) infection of pig-tailed macaques. The results show that during the first few months after HTLV-I(ACH) infection, activation of both innate and adaptive immunity, limited virus-specific cellular responses, sustained immune system activation, and, in some cases, immunodeficiency were evident. Thus, this animal model might be valuable for understanding early stages of infection and causes of immune system dysregulation in HTLV-I-infected humans.

Human T lymphotropic virus type 1 in a seronegative B chronic lymphocytic leukemia patient.

Human T lymphotropic virus type 1 (HTLV-1) is the etiological agent of adult T cell leukemia and HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-1 infection in patients with B cell-type chronic lymphocytic leukemia (B-CLL) is rare and has been reported only in areas in which HTLV-1 is endemic. In the present study, we detected HTLV-1 proviral DNA by polymerase chain reaction, using tax primers, in peripheral blood lymphocytes from a B-CLL patient, an immigrant to Israel, where HTLV-1 infection is not endemic. F344 rats injected intravenously with peripheral blood lymphocytes obtained from the patient developed HTLV-1 antibodies. Titers of antibody to HTLV-1 in the rat blood were 1:512 by particle agglutination; enzyme-linked immunosorbent assay and Western blotting were also positive. No antibody against HTLV-1 was demonstrated in the animal model after inoculation of either purified B lymphocytes from the B-CLL patient or peripheral blood mononuclear cells from healthy donors. This is one of the few studies showing the presence of HTLV-1 provirus in T lymphocytes of a B-CLL patient who had multiple infections, and died of salmonella sepsis, and the first report of HTLV-1 antibody induction in an animal model by inoculation of lymphocytes obtained from an HTLV-1-infected B-CLL patient.

Predictive markers for development of strongyloidiasis in patients infected with both Strongyloides stercoralis and HTLV-1.

Severe strongyloidiasis has often been reported to occur in some patients infected with both Strongyloides stercoralis (S. stercoralis) and human T-cell leukaemia virus type 1 (HTLV-1); however, there are few useful predictive markers for the risk of development of strongyloidiasis in these patients. To search for such predictive markers, we examined peripheral blood and stool samples of individuals infected with both S. stercoralis and HTLV-1 in Okinawa, Japan, an area in which both of these are endemic. The HTLV-1 proviral load and antibody titre were examined in relation to the S. stercoralis load as measured by the direct faecal smear method in patients infected with both S. stercoralis and HTLV-1. The Epstein-Barr virus (EBV)-associated nuclear antigen (EBNA) antibody titre was also measured in these patients in order to examine the relationship between host immunity and HTLV-1 proviral load or antibody titre. The direct faecal smear-positive group showed both a higher HTLV-1 proviral load and HTLV-1 antibody titre than the -negative group (P < 0.05). In contrast, inverse correlations of these parameters with the EBNA antibody titre were observed, especially for proviral load (rho = -0.387, P < 0.05). These results suggest that HTLV-1 proviral load and antibody titre influence the S. stercoralis load via disturbance of the host immunity, and that proviral load would be an especially useful predictive marker of the risk of development of strongyloidiasis in patients infected with both S. stercoralis and HTLV-1.

Human T-cell lymphotropic virus type 1-associated retinal vasculitis in children.

PURPOSE: To describe predominant retinal vasculitis in children carrying human T-cell lymphotropic virus type 1 (HTLV-1). METHODS: The authors examined clinical records of patients with HTLV-1-associated uveitis between 1987 and 2001 in Kagoshima University Hospital and reviewed cases of extensive, smoldering retinal vasculitis. RESULTS: Three previously healthy teenagers noted mild visual symptoms and presented with extensive sheathing of retinal vessels, complicated by mild anterior segment inflammation. The retinal vascular disease responded poorly to systemic corticosteroids, had a smoldering course with persistent sheathing of retinal vessels, and eventually resulted in diffuse chorioretinal degeneration. Results of laboratory studies were unremarkable except for the presence of serum antibodies to HTLV-1. One patient developed HTLV-1-associated myelopathy 11 years after the onset of ocular disease. CONCLUSIONS: The retinal vasculitis differed from the retinal vascular changes commonly seen in HTLV-1-associated uveitis. The authors suggest a clinical disease HTLV-1-associated retinal vasculitis that affects young HTLV-1 carriers, characterized by smoldering retinal vasculitis with ultimate retinal degeneration.