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The diagnosis of human T-cell leukemia virus type-1 (HTLV-1) infection has been widely examined by serologics. In the first screening tests, serological false negative and positive samples have been reduced thanks to advances in assay techniques that apply new emission agents and sensors. On the other hand, western blot (WB) remains problematic. For example, WB analysis yields many samples equivalent to antibody positive ones. To reduce the need for WB, an alternative testing strategy is required to detect HTLV-1 infection. Polymerase chain reaction (PCR) for the HTLV-1 provirus has recently been recommended for a final diagnosis of infection. However, although PCR is thought to be one element, the validation of detection performance for HTLV-1 infection between serological and molecular testing is not always clear. Thus, this study aimed to evaluate the accuracy and test the validity of an improved methodology for serological detection of HTLV-infection, as well as that of PCR. In conclusion, the high values of kappa-statistics are expected to deliver high quality in chemiluminescent enzyme immunoassay (or chemiluminescent immunoassay), while the problems with WB assays remain to be elucidated. As an alternative to WB, a combination of real-time qPCR and nested PCR is proposed as a suitable confirmatory test.

Severe and life-threatening donor-transmitted human T-cell leukemia virus type 1 (HTLV-1) infections after solid organ transplantation have been reported. However, in HTLV-1-infected recipients, graft and patient survival were not fully evaluated. A total of 140 patients underwent living donor liver transplantation (LDLT). Of these, 47 of 126 adult recipients showed indications of hepatitis C virus (HCV)-related liver disease. The HTLV-1 prevalence rate was 10 of 140 recipients (7.14%) and three of 140 donors (0.02%). In HCV-related LDLT, graft and patient survival was worsened by HTLV-1 infection in recipients (seven cases). The 1-, 3-, and 5-year survival rates in the HCV/HTLV-1-co-infected group were 67%, 32%, and 15%, respectively, and the corresponding rates in the HCV-mono-infected group were 80%, 67%, and 67%, respectively. Only the 5-year survival rates were statistically significant (P=0.04, log-rank method). HTLV-1 infection in recipients is also an important factor in predicting survival in HTLV-1 endemic areas., (© 2012 The Authors. Transplant International © 2012 European Society for Organ Transplantation.)

Background: Human T-cell leukemia virus type-1 (HTLV-1) carriers co-infected with and hepatitis C virus (HCV) have been known to be at higher risk of their related diseases than mono-infected individuals. The recent studies clarified that IL-28B polymorphism rs8099917 is associated with not only the HCV therapeutic response by IFN, but also innate immunity and antiviral activity. The aim of our research was to clarify study whether IL-28B gene polymorphism (rs8099917) is associated with HTLV-1/HCV co-infection., Results: The genotyping and viral-serological analysis for 340 individuals showed that IL-28B genotype distribution of rs8099917 SNP did not differ significantly by respective viral infection status. However, the IL-28B mRNA expression level was 3.8 fold higher in HTLV-1 mono-infection than HTLV-1/HCV co-infection. The high expression level was associated with TT (OR, 6.25), whiles the low expression was associated with co-infection of the two viruses (OR, 9.5). However, there was no association between down-regulation and ATL development (OR, 0.8)., Conclusion: HTLV-1 mono-infection up-regulates the expression of IL-28B transcripts in genotype-dependent manner, whiles HTLV-1/HCV co-infection down-regulates regardless of ATL development.

Few studies have specifically examined defective provirus in asymptomatic human T-lymphotropic virus Type 1 (HTLV-1) carriers and its relation to proviral DNA loads (PVLs). To assess the significance of defective provirus in asymptomatic carriers, we examined PVLs in peripheral blood mononuclear cells of 208 asymptomatic HTLV-1 carriers. The mean PVLs determined using primers for the pol region were less than that for the pX region in these carriers. Analysis of seven carriers with high PVLs for the pX region but lower PVLs for the pol region showed that four had single nucleotide polymorphisms of proviral genomes for the pol region and three had HTLV-1-infected cells with defective provirus. Three carriers with defective provirus showed high PVLs at their initial screens, and PVLs increased after a 10- to 12-year interval in two carriers. Southern blot assay showed clonal expansion of HTLV-1-infected cells, and the predominant clones changed during the observation period. These data suggest that although HTLV-1-infected cells with defective provirus may have a growth advantage, the predominant clones of HTLV-1-infected cells do not always survive for many years in asymptomatic carriers., (Copyright © 2010 UICC.)

Definitive risk factors for the development of adult T-cell leukemia (ATL) among asymptomatic human T-cell leukemia virus type I (HTLV-1) carriers remain unclear. Recently, HTLV-1 proviral loads have been evaluated as important predictors of ATL, but a few small prospective studies have been conducted. We prospectively evaluated 1218 asymptomatic HTLV-1 carriers (426 males and 792 females) who were enrolled during 2002 to 2008. The proviral load at enrollment was significantly higher in males than females (median, 2.10 vs 1.39 copies/100 peripheral blood mononuclear cells [PBMCs]; P < .001), in those 40 to 49 and 50 to 59 years of age than that of those 40 years of age and younger (P = .02 and .007, respectively), and in those with a family history of ATL than those without the history (median, 2.32 vs 1.33 copies/100 PBMCs; P = .005). During follow-up, 14 participants progressed to overt ATL. Their baseline proviral load was high (range, 4.17-28.58 copies/100 PBMCs). None developed ATL among those with a baseline proviral load lower than approximately 4 copies. Multivariate Cox analyses indicated that not only a higher proviral load, advanced age, family history of ATL, and first opportunity for HTLV-1 testing during treatment for other diseases were independent risk factors for progression of ATL.

Background: To address the clinical and virological significance of a high HTLV-1 proviral load (VL) in practical blood samples from asymptomatic and symptomatic carriers, we simultaneously examined VL and clonal expansion status using polymerase chain reaction (PCR) quantification (infected cell % of peripheral mononuclear cells) and Southern blotting hybridization (SBH) methods., Results: The present study disclosed extremely high VL with highly dense smears with or without oligoclonal bands in SBH. A high VL of 10% or more was observed in 16 (43.2%) of a total of 33 samples (one of 13 asymptomatic carriers, 8 of 12 symptomatic carriers, and 7 of 8 patients with lymphoma-type ATL without circulating ATL cells). In particular, an extremely high VL of 50% or more was limited to symptomatic carriers whose band findings always contained at least dense smears derived from polyclonally expanded cells infected with HTLV-1. Sequential samples revealed that the VL value was synchronized with the presence or absence of dense smears, and declined at the same time as disappearing dense smears. Dense smears transiently emerged at the active stage of the underlying disease. After disappearance of the smears, several clonal bands became visible and were persistently retained, explaining the process by which the clonality of HTLV-1-infected cells is established. The cases with only oligoclonal bands tended to maintain a stable VL of around 20% for a long time. Two of such cases developed ATL 4 and 3.5 years later, suggesting that a high VL with oligoclonal bands may be a predisposing risk to ATL., Conclusion: The main contributor to extremely high VL seems to be transient emergence of dense smears detected by the sensitivity level of SBH, corresponding to polyclonal expansion of HTLV-1-infected cells including abundant small clones. Major clones retained after disappearance of dense smears stably persist and acquire various malignant characteristics step by step.

Most previous studies aimed at estimating the number of human T-cell leukemia virus type-1 (HTLV-1) carriers in endemic areas have been based on seroprevalence rates in blood donors; however, this may result in underestimation because of the healthy donor effect. People who have health problem do not donate blood. In the present study, the number of HTLV-1 carriers in Nagasaki City was estimated based on the seroprevalence rates in a hospital-based population from Nagasaki University Hospital. In accordance with previous reports, seroprevalence of HTLV-1 was higher in females, and year of birth-specific seroprevalence showed a significant annual decline in both genders (P for trend: <0.0001). The estimated number of HTLV-1 carriers in Nagasaki City was 36,983. The incidence of adult T-cell leukemia/lymphoma (ATLL) among HTLV-1 carriers was estimated using data from the Nagasaki Prefectural Cancer Registry. The estimated annual incidence of ATLL was 61 per 100,000 HTLV-1 carriers, and the crude lifetime risk of the development was 7.29% for males and 3.78% for females. There is a large pool of HTLV-1 carriers aged over 70 years, and a continuing development of cases of ATLL among the elderly is therefore expected., (2010 Wiley-Liss, Inc.)

Human T cell leukemia virus type-1 (HTLV-1) is the established cause of adult T cell leukemia/lymphoma. Monitoring time trends in HTLV-1 seroprevalence in blood donors is important to assess the safety of the blood supply in the viral endemic area. We analyzed changes in HTLV-1 seroprevalence in 48415 first-time blood donors who donated blood from 2000 to 2006 in Nagasaki prefecture, an endemic area in Japan. The donors were divided into 10-year birth cohorts: before 1950, 1951-1960, 1961-1970, 1971-1980, and 1981-1990. Among the first-time blood donors, 622 were tested positive for HTLV-1 [overall seroprevalence: 1.28%, (95% CI 1.19-1.39)]. Seroprevalence was significantly high in the birth cohort of before 1950 (6.22%) and declined with birth-year. The time trend of the birth-cohort-specific seroprevalence showed almost no change within each birth cohort, except for the birth cohort of 1981-1990 that showed a significantly declining trend (P for trend = 0.006). Among the birth cohort of 1981-1990, the seroprevalence was stable among those born during 1981-1986 (0.66-0.83%), but was lower among those born during 1987-1990 (0-0.38%). Detail analyses showed that HTLV-1 seroprevalence among blood donors clearly declined in those born after 1987.

Background: HTLV-1 causes adult T-cell leukemia (ATL). Although there have been many studies on the oncogenesis of the viral protein Tax, the precise oncogenic mechanism remains to be elucidated. Recently, a new viral factor, HTLV-1 basic Zip factor (HBZ), encoded from the minus strand mRNA was discovered and the current models of Tax-centered ATL cell pathogenesis are in conflict with this discovery. HBZs consisting of non-spliced and spliced isoforms (HBZ-SI) are thought to be implicated in viral replication and T-cell proliferation but there is little evidence on the HBZ expression profile on a large scale., Results: To investigate the role of HBZ-SI in HTLV-1 provirus-positive cells, the HBZ-SI and Tax mRNA loads in samples with a mixture of infected and non-infected cells were measured and then adjusted by dividing by the HTLV-I proviral load. We show here that the HBZ-SI mRNA level is 4-fold higher than non-spliced HBZ and is expressed by almost all cells harboring HTLV-1 provirus with variable intensity. The proviral-adjusted HBZ-SI and Tax quantification revealed a characteristic imbalanced expression feature of high HBZ and low Tax expression levels in primary ATL cells or high HBZ and very high Tax levels in HTLV-1-related cell lines (cell lines) compared with a standard expression profile of low HBZ and low Tax in infected cells. Interestingly, according to the mutual Tax and HBZ expression status, HTLV-1-related cell lines were subcategorized into two groups, an ATL cell type with high HBZ and low Tax levels and another type with high Tax and either high or low HBZ, which was closely related to its cell origin., Conclusion: This is the first comprehensive study to evaluate the mutual expression profile of HBZ and Tax in provirus-positive cells, revealing that there are quantitative and relative characteristic features among infected cells, primary ATL cells, and cell lines.

Resveratrol, a phytoalexin found in grapes and wine, has been shown to exhibit a wide range of pharmacological properties and is believed to play a role in the chemoprevention of human cancer. Resveratrol has also been shown to induce antiproliferation and apoptosis of several leukemia cell lines. In the present study, we investigated the effect of resveratrol in adult T cell leukemia. Our present observations showed that resveratrol induced growth inhibition in all five human T cell lymphotrophic virus-1-infected cell lines examined, with 50% effective dose of 10.4-85.6 mM. In the resveratrol-treated cells, induction of apoptosis was confirmed by annexin V-based analyses and morphological changes. The most surprising observation was that resveratrol treatment resulted in a gradual decrease in the expression of survivin, an antiapoptotic protein, during cell apoptosis. These findings indicate that resveratrol inhibits the growth of human T cell lymphotrophic virus-1-infected cell lines, at least in part, by inducing apoptosis mediated by downregulation in survivin expression. In view of the accumulating evidence that survivin may be an important determinant of a clinical response in adult T cell leukemia, our present findings have led to the suggestion that resveratrol, a common constituent of the human diet, merits further investigation as a potential therapeutic agent for this incurable disease.

Background: The prevalence of Helicobacter pylori in HIV-positive individuals is significantly lower than in HIV-negative controls. However, its prevalence in individuals infected with human T-cell leukaemia virus type I (HTLV-I), another important member of the human retrovirus family, has not been previously investigated., Objective: To establish the prevalence of H. pylori in HTLV-I-positive individuals in the Nagasaki Prefecture, which is an area endemic for HTLV-I., Methods: We examined sera from 146 HTLV-I-positive individuals with a mean age of 56.7 years, consisting of 45 adult T-cell leukaemia (ATL) patients, 13 HTLV-I-associated myelopathy (HAM) patients and 88 healthy carriers. Serum samples of 292 age- and sex-matched HTLV-I-negative controls were also examined. Serum anti-H. pylori immunoglobulin (Ig) G antibody was examined using an enzyme-linked immunosorbent assay kit. Twenty-eight HTLV-I-positive patients were examined endoscopically, assessed for H. pylori by culture, histology and CLO test using gastric biopsy specimens, and gastritis in these patients was also graded histologically., Results: The seroprevalence of H. pylori was 48% in HTLV-I-positive individuals versus 64% in HTLV-I-negative controls (P < 0.01). In the three HTLV-I-positive groups, ATL patients and carriers had significantly lower seroprevalence of H. pylori than the HTLV-I-negative controls (P < 0.05). Assessment of H. pylori using gastric biopsy specimens also showed a significantly lower prevalence of H. pylori infection in HTLV-I-positive patients than controls (46% versus 70%, P < 0.05). Histological examination showed a significantly higher degree of activity, inflammation and glandular atrophy in the antrum and corpus in H. pylori-positive patients compared to H. pylori-negative patients. H. pylori-positive patients with HTLV-I infection had a more severe degree of glandular atrophy in the corpus than H. pylori-positive controls without HTLV-I infection., Conclusion: We have found a reduced prevalence of H. pylori in HTLV-I-positive individuals. Whatever the explanation, infection with HTLV-I does not predispose to the risk of H. pylori infection.

We established a simple IL-2-dependent colony-forming assay for T cells infected with human T-lymphotropic virus type-I (HTLV-I). IL-2-dependent cell lines were subsequently established by expanding individual colonies in liquid cultures. Lymphocyte-rich fractions were prepared from 31 HTLV-I carriers, 12 patients with smoldering ATL, 11 chronic ATL, 12 crisis ATL and 10 acute ATL. Primary colonies of CD4+ p19+ T cells were formed in all cases of carriers, smoldering and chronic ATL, and in 10 of 12 crisis cases. In contrast, no colony was formed from cells of patients with acute ATL. The rate of establishment of cell lines in HTLV-I carriers was significantly lower than that in patients of prodromal phase ATL. Cell lines established from cells of three prodromal cases were clonally identical to the parent ATL cells, while others had clonally distinct cell lines. Our results indicated the presence of four components of HTLV-I-infected T cells: (1) normal carrier T cells capable of forming colonies but not cell lines; (2) pre-malignant T cells capable of forming colonies as well as cell lines; (3) malignant T cells capable of forming colonies as well as cell lines; (4) fully malignant T cells unresponsive to IL-2. Our results suggest the presence of a multiclonal expansion of unique T cells in the prodromal phase of ATL, which have a high growth potential in response to IL-2. The coexistence of multiclonality with a dominant ATL clone may be closely related to the underlying pathology in HTLV-I leukemogenesis.

We studied the serologic status, with respect to hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-lymphotropic virus type-I (HTLV-I) of blood donors in an area endemic for adult T-cell leukemia (ATL). Similarly, we studied the serologic status of hepatocellular carcinoma (HCC) patients from the same district. In the donors, the incidence of serological positivity for these viruses was 0.95, 1.23, and 3.75%, respectively. There was a positive correlation between the presence of anti-HCV and serological HTLV-I positive status in these subjects (1.9 vs. 1.1%) for those with HTLV-I negative status, implying high susceptibility for HCV infection among HTLV-I carriers. Fifty-nine percent of HCC patients were positive for anti-HCV and twenty-six percent of those were simultaneously positive for the antibody to HTLV-I. HCC patients infected with HTLV-I were younger than patients not so infected (61.5 +/- 8.8 vs. 64.8 +/- 8.4 years, p < 0.05). These observations suggest the possibility that HTLV-I could be one of the factors that promote the development of HCC caused by hepatotropic viruses.

We tested for antibodies to hepatitis B virus (HBV), hepatitis C virus (HCV), and human T lymphotropic virus type-I (HTLV-I) in 629 normal inhabitants of an adult T cell leukemia (ATL) endemic area and in patients with ATL, HTLV-I associated myelopathy (HAM), and hepatocellular carcinoma (HCC) from the same district. The prevalence of serological positivity for each virus was 28.0, 6.4, and 32.6%, respectively, among the 629 inhabitants. There was a positive association between the presence of anti-HCV and serological HTLV-I positive or negative status of these subjects (9.3% vs 5.0%). Conversely, there was no correlation between HBV and HTLV-I serologic prevalence. Only inhabitants positive for anti-HCV showed significantly high serum aminotransferase levels. The levels were not affected by superimposed HTLV-I infection among anti-HCV positives. Fifty three percent of HCC patients were positive for anti-HCV; 35% of whom were simultaneously positive for antibody to HTLV-I. On the other hand, only 2 ATL patients (4.2%) and 2 HAM patients (7.7%) had anti-HCV. These findings suggest that high serum aminotransferase levels are mainly caused by HCV infection and persons with HCV and HTLV-I double infections are at a high risk for the development of HCC but not ATL or HAM.

Particle agglutination (PA; Serodia-ATLA) and ELISA (Ei-test ATL) assays have been used as routine anti-HTLV-I antibody detection in Japan. However, inconsistent results were obtained by the above methods. We wished to develop criteria for serological confirmation of HTLV-I infection in Hospital samples. Sera obtained in our Hospital from October, 1988 to September, 1989 were tested by five methods of PA (Serodia-ATLA), new PA (improved on the PA; Serodia.HTLV-I), ELISA-I (coated by HTLV-I infected cell lysates as antigens; Ei-test ATL), ELISA-II (coated by recombinant gag-env hybrid proteins as antigens) and IF. The HTLV-I seropositive rates using five methods were not different, ranged from 29.7 to 32.3% in 155 sera. However, PA assays appeared more false positive and rare false negative in some high titer sera. 13 sera as demonstrated negative for ELISA-I and positive for PA (ELISA-I(-)/PA(+] were reevaluated. As results, the antibody were confirmed in only 3 by new PA, 1 by ELISA-II and 2 cases by IF, respectively. On the other hand, 2 by new PA, 4 by ELISA-II and 2 by IF in 18 sera with ELISA-I(+)/PA(-) were interpreted as positive. Therefore, new PA is a remarkable improvement on the PA current model.

A new enzyme-linked immunosorbent assay (ELISA) for detecting the antibody to a human T-lymphotropic virus type I (HTLV-I) tax gene product, p40tax, has been developed. By this ELISA method, we have investigated the relationship between the presence of p40tax antibody in HTLV-I-infected mothers and the virus transmission rate from mothers to their children. The rate of mother-to-child transmission of HTLV-I was higher in p40tax antibody-positive mothers than in antibody-negative ones. Thus, the presence of p40tax antibody may indicate an increased risk of vertical transmission of HTLV-I.

We investigated antibodies against pX gene product, p40tax, by ELISA using recombinant p40tax protein in HTLV-I seropositive carriers as well as patients with adult T cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM). Seventy (49.0%) out of 143 HTLV-I healthy carriers were found to be positive for antibody against p40tax antigen and the follow-up samples at two-year intervals revealed constant reactivity by ELISA in each carrier. The onset of antibody production was delayed 4 to 12 weeks as compared with anti-HTLV-I in primary infection cases. The anti-p40tax-positive rate (90%) in HAM patients was significantly higher than that of healthy carriers, acute and chronic ATL patients and their family members. Furthermore, HAM patients and a few healthy carriers showed high reactivities by ELISA. Children from mothers with anti-p40tax showed a higher anti-HTLV-I-positive rate than that of children from mothers without anti-p40tax (54.5% versus 12.5%). Two men without anti-p40tax and one female with low anti-p40tax developed ATL during follow-up studies. These results suggest that HTLV-I carriers could be divided into 2 or 3 sub-populations according to antibody response to p40tax. A smaller population with anti-p40tax, especially a high antibody reactivity, could have a high risk of developing HAM and of transmission from mother to child. In addition, ATL may occur in a population with low or absent anti-p40tax.

Healthy blood donors, patients with adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy (HAM) and recipients of unscreened blood (SR) who had seroconverted and were followed-up for more than 2 years were examined for HTLV-I antibodies of immunoglobulin G (IgG) and M(IgM) classes. The overall infection rate in donors was 4.9%, as determined by screening with a particle agglutination method (PA). The rate increased with increasing age. Positive sera with a low titer in the PA test (1/16, 1/32 and 1/64) contained IgM antibodies in 32.5% (titer 1/16) to 36.1% (titer 1/64) of the cases, but IgG antibodies were detected in only 5.6% of the sera with a titer of 1/16 and in 36.1% of the sera with a titer of 1/64. Conversely, in high titer sera (1/128 or higher) IgG antibodies were almost always detectable (99.0%) and IgM antibodies less frequently (25.5%). Sera from acute, chronic and pre-ATL, HAM and SR patients contained IgG antibodies in high titer in all cases. The incidence of IgM antibodies was 7.7, 30.0, 53.3, 72.3, and 77.8%, respectively. IgM antibodies were demonstrated repeatedly in some cases who were followed up for a year. Only IgM antibodies from HAM patients occurred in high titers and had strong reactivity to the p24 antigens of HTLV-I in Western blot testing. It is concluded that it is important to detect IgM antibodies not only in primary infections but also in persistent infections of HTLV-I.

Healthy carriers, patients with ATL and HTLV-I associated myelopathy (HAM) were examined for HTLV-I antibodies of IgG and IgM classes and anti-p 40x antibodies, using ELISA, western blot (WB) and particle agglutination (PA) techniques. IgG antibodies were almost always detectable in sera from all of patients with ATL and HAM and healthy carriers with high titer in the PA test (normal carriers), and the average value of OD 405 was 2.0 +/- 0.3, 1.6 +/- 0.6 and 1.3 +/- 0.7, respectively. In anti-p 40x antibodies, the detectable incidence of HAM, ATL, normal carriers and carriers with low titer of the PA (low-PA group) was 90%, 67%, 44%, and 3%; and, the average value of OD 405 of the antibodies was 2.3 +/- 1.0, 0.7 +/- 0.5, and 0.7 +/- 0.7, respectively. On the other hand, the incidence of IgM antibodies demonstrated in HAM, ATL, normal carriers and low-PA group was 90%, 41%, 33%, and 53%, respectively. Furthermore, the follow-up observation of these antibodies revealed that the antibody profile of individuals for a long time was constant, i.e. in each carrier the value with high OD remained high and the presence of anti-p 40x and/or IgM antibodies remained present. These data has demonstrated that there are considerably differences among individuals in responsivilities for HTLV-I. Then, the antibody profile is mainly classified into 3 groups; hyper-, common- and hypo-immune patterns.