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Background An increased risk of total death owing to human T-lymphotropic virus type-I (HTLV-I) infection has been reported. However, its etiology and protective factors are unclear. Various studies reported fluctuations in immune-inflammatory status among HTLV-I carriers. We conducted a matched cohort study among the general population in an HTLV-I-endemic region of Japan to investigate the interaction between inflammatory gene polymorphisms and HTLV-I infection for total death, incidence of cancer, and atherosclerosis-related diseases. Method We selected 2180 sub-cohort subjects aged 35–69 years from the cohort population, after matching for age, sex, and region with HTLV-I seropositives. They were followed up for a maximum of 10 years. Inflammatory gene polymorphisms were selected from TNF-α, IL-10, and NF-κB1. A Cox proportional hazard model was used to estimate the hazard ratio (HR) and the interaction between gene polymorphisms and HTLV-I for risk of total death and incidence of cancer and atherosclerosis-related diseases. Results HTLV-I seropositivity rate was 6.4% in the cohort population. The interaction between TNF-α 1031T/C and HTLV-I for atherosclerosis-related disease incidence was statistically significant (p = 0.020). No significant interaction was observed between IL-10 819T/C or NF-κB1 94ATTG ins/del and HTLV-I. An increased HR for total death was observed in the Amami island region, after adjustment of various factors with gene polymorphisms (HR 3.03; 95% confidence interval, 1.18–7.77). Conclusion The present study found the interaction between TNF-α 1031T/C and HTLV-I to be a risk factor for atherosclerosis-related disease. Further follow-up is warranted to investigate protective factors against developing diseases among susceptible HTLV-I carriers., Highlights • We observed death and incidence risk with HTLV-I and SNPs in a matched cohort study. • An increased risk for total death with HTLV-I was observed in the island region. • Inflammatory SNP interacted with HTLV-I for atherosclerosis-related disease risk.

Background The risk of transferring blood-borne infections during transfusion is continually increasing because of newly emerging and reemerging viruses. Development of a rapid screening method for emerging viruses that might be transmitted by transfusion is required to eliminate such pathogens during blood donor screening. Owing to increased use of human materials in organ transplants and cell therapy, the risk of donor-transmitted viral infections is also increasing. Although nucleic acid amplification technology (NAT) is dedicated to blood screening, a small, convenient detection system is needed at the laboratory and hospital level. Study Design and Methods We developed a new pathogen detection system that can detect multiple viruses simultaneously, using originally designed degenerate polymerase chain reaction primers to amplify a wide range of viral genotypes. Amplified samples were identified using a DNA microarray of pathogen-specific probes. Results We detected very low copy numbers of multiple subtypes of viruses, such as human hepatitis C virus (HCV), human hepatitis B virus (HBV), human parvovirus B19 (PVB19), and West Nile virus (WNV), using a single plate. We also detected all genotypes of human immunodeficiency virus (HIV) but sensitivity was less than for the other viruses. Conclusion We developed a microarray assay using novel primers for detection of a wide range of multiple pathogens and subtypes. Our NAT system was accurate and reliable for detection of HIV, HBV, HCV, PVB19, and WNV, with respect to specificity, sensitivity, and genotype inclusivity. Our system could be customized and extended for emerging pathogens and is suitable as a future NAT system.

Molecular abnormalities involved in the multistep leukemogenesis of adult T-cell leukemia (ATL) remain to be clarified. Based on our integrated database, we focused on the expression patterns and levels of Ikaros family genes, Ikaros, Helios, and Aiolos, in ATL patients and HTLV-1 carriers. The results revealed profound deregulation of Helios expression, a pivotal regulator in the control of T-cell differentiation and activation. The majority of ATL samples (32/37 cases) showed abnormal splicing of Helios expression, and four cases did not express Helios. In addition, novel genomic loss in Helios locus was observed in 17/168 cases. We identified four ATL-specific short Helios isoforms and revealed their dominant-negative function. Ectopic expression of ATL-type Helios isoform as well as knockdown of normal Helios or Ikaros promoted T-cell growth. Global mRNA profiling and pathway analysis showed activation of several signaling pathways important for lymphocyte proliferation and survival. These data provide new insights into the molecular involvement of Helios function in the leukemogenesis and phenotype of ATL cells, indicating that Helios deregulation is one of the novel molecular hallmarks of ATL.

Background Bacterial infections cause an increase in the population of hematopoietic stem cells (HSCs). To investigate the downstream factors associated with hematopoietic stem cells, mice are infected with Mycobacterium avium (M. avium). Results Mycobacterium avium (M. avium) infection induces the enlargement of the spleen and changes in histopathology, including changes to the lineage populations. A dramatic expansion of Lin−c-kit+Sca-1+ (KSL) cells in mouse bone marrow cells and spleen cells was detected 4 weeks after infection with M. avium; however, there was no difference in the engraft activity between infected and un-infected mouse bone marrow cells. We tested the cytokine and cytokine-related gene expression after M. avium infection and found that IFN-γ expression increased and peaked at 4 weeks in both bone marrow and spleen cells. The expression of Sca-1 gene peaked at 4 weeks in the bone marrow but peaked at 2 weeks in spleen cells, although the Sca-1 surface marker peaked at 4 weeks after infection in both bone marrow and spleen cells. Interferon regulatory factor-2 (IRF-2) expression did not change in the bone marrow cells, whereas it decreased in spleen cells at 4 weeks and IRF-1 expression was up-regulated in both bone marrow and spleen cells after infection. However, the up-regulation of IRF-1 was not correlated with IFN-γ expression in the M. avium-infected mouse spleen cells. Conclusions This finding suggests that the IFN-γ production mediated by M. avium infection alters the population of KSL cells during host defense, and the down-regulation of the IFN-γ response in spleen cells occurs at the late stage after M. avium infection.

A patient previously treated for Hodgkin's disease (HD) developed secondary adult T cell leukaemia/lymphoma (ATL) after blood transfusion. Immunohistochemical analysis and polymerase chain reaction support the diagnosis. To the best of our knowledge this is the first occurrence of transfusion induced ATL occurring as a second malignancy after treatment for HD. The leukaemia/lymphoma probably developed on the basis of underlying immunosuppression.

Fifty percent of Diamond-Blackfan anemia (DBA) patients possess mutations in genes coding for ribosomal proteins (RPs). To identify new mutations, we investigated large deletions in the RP genes RPL5, RPL11, RPL35A, RPS7, RPS10, RPS17, RPS19, RPS24, and RPS26. We developed an easy method based on quantitative-PCR in which the threshold cycle correlates to gene copy number. Using this approach, we were able to diagnose 7 of 27 Japanese patients (25.9%) possessing mutations that were not detected by sequencing. Among these large deletions, similar results were obtained with 6 of 7 patients screened with a single nucleotide polymorphism array. We found an extensive intragenic deletion in RPS19, including exons 1-3. We also found 1 proband with an RPL5 deletion, 1 patient with an RPL35A deletion, 3 with RPS17 deletions, and 1 with an RPS19 deletion. In particular, the large deletions in the RPL5 and RPS17 alleles are novel. All patients with a large deletion had a growth retardation phenotype. Our data suggest that large deletions in RP genes comprise a sizable fraction of DBA patients in Japan. In addition, our novel approach may become a useful tool for screening gene copy numbers of known DBA genes.

Human T-cell leukemia virus type-1 (HTLV-1), a major source of adult T-cell leukemia and related diseases, is endemic to southwestern Japan. Mother-to-infant transmission via breast milk is an important route of infection, and establishing programs to prevent such transmission requires exact figures on the HTLV-1 prevalence rate and the number of carriers. Therefore, the seroprevalence of HTLV-1 among 1,196,321 Japanese first-time blood donors from 2006 to 2007 was investigated. A total of 3,787 of such donors were confirmed to be positive for anti-HTLV-1 antibody. By applying a fitness curve to the age ranges outside the blood donor age range, the present number of HTLV-1 carriers covering ages from 0 to 99 years was estimated to be at least 1.08 million in Japan; this value was 10% lower than that reported in 1988. The adjusted overall prevalence rates were estimated to be 0.66% and 1.02% in men and women, respectively. The peak in carrier numbers was found among individuals in their 70s, which is a shift from the previous peak observed in the 1988 database among individuals in their 50s. Carriers were distributed not only in the endemic southwestern region of Japan, but throughout the country, particularly in the greater Tokyo metropolitan area. By applying population projections, it was calculated that the carrier number will decrease by half in the next two decades; however, the carrier population will age over that interval, meaning that the age of patients with adult T-cell leukemia will also be higher.

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.

It has been suggested that hepatitis C virus (HCV) infects not only hepatocytes but also immune cells, including B cells. HCV infection of B cells is the likely cause of B-cell dysregulation disorders such as mixed cryoglobulinemia, rheumatoid factor production, and B-cell lymphoproliferative disorders that may evolve into non-Hodgkin's lymphoma. To clarify the effects of chronic HCV infection on B-cell dynamics, peripheral B cells from chronic hepatitis C patients (CHC) were characterized. We found that the frequency of CD27(+) B cells, that is memory phenotype, was significantly reduced in the peripheral blood of CHC. At the same time, the amount of IFN-gamma-inducible protein-10 (IP-10), a CXCR3 ligand, was markedly elevated in the plasma of CHC. Furthermore, the CD27(+) B-cell population was found to highly express CXCR3 in CHC, thus suggesting that the CD27(+) B-cell population was recruited from peripheral blood to the inflammatory site of the liver of CHC, where IP-10 is produced. Immunohistochemical analyses of intrahepatic lymphocytes indicated that CXCR3(+) B cells were infiltrated in the liver of CHC. Our results thus offer new insight into the role of memory B cells in the HCV pathogenesis.

Adult T-cell leukemia/lymphoma (ATL) is a malignant lymphoproliferative disorder caused by HTLV-I infection. In ATL, chemotherapeutic responses are generally poor, which has suggested the existence of chemotherapy-resistant cancer stem cells (CSCs). To identify CSC candidates in ATL, we have focused on a Tax transgenic mouse (Tax-Tg) model, which reproduces ATL-like disease both in Tax-Tg animals and also after transfer of Tax-Tg splenic lymphomatous cells (SLCs) to nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice. Using a limiting dilution transplantation, it was estimated that one CSC existed per 104 SLCs (0.01%). In agreement with this, we have successfully identified candidate CSCs in a side population (0.06%), which overlapped with a minor population of CD38−/CD71−/CD117+ cells (0.03%). Whereas lymphoma did not develop after transplantation of 102 SLCs, 102 CSCs could consistently regenerate the original lymphoma. In addition, lymphoma and CSCs could also be demonstrated in the bone marrow and CD117+ CSCs were observed in both osteoblastic and vascular niches. In the CSCs, Tax, Notch1, and Bmi1 expression was down-regulated, suggesting that the CSCs were derived from Pro-T cells or early hematopoietic progenitor cells. Taken together, our data demonstrate that CSCs certainly exist and have the potential to regenerate lymphoma in our mouse model.

Although vaccines are routinely used to prevent infectious diseases, little is known about the comprehensive influences caused by vaccines. In this study, we showed, using comprehensive gene expression analysis, that pertussis vaccine affected many genes in multiple organs of vaccine-treated animals. In particular, lung was revealed to be the most suitable target to evaluate pertussis vaccine toxicity. The 13 genes identified from the analysis of vaccine-treated lung at day 1 showed a clear dendrogram corresponding to pertussis vaccine toxicity. Furthermore, quantitative analysis of these genes revealed a positive correlation between their respective expression levels and the degree of toxic effects observed in samples that had been treated with various doses of reference pertussis vaccines. The quantification of this 13 gene-set is an indicator of the vaccine toxicity-related reaction.

Conventional animal tests such as leukocytosis promoting tests have been used for decades to evaluate toxicity of pertussis vaccine. Here, we examined gene expression in relation to the vaccine toxicity using a DNA microarray. Comparison of conventional animal test data with the DNA microarray-based gene expression data revealed a gene expression pattern highly correlated with leukocytosis in animals. Of 10,490 rat genes analyzed, two genes, alpha1-acid-glycoprotein (Agp) and hemopexin (Hpx), were found up-regulated by the toxin administration in a dose-dependent manner (assayed by a quantitative PCR based on the microarray). Variation of the gene expression was very small amongst the test animals, and the results were highly reproducible. These findings suggest that gene expression analysis of vaccine-treated animals can be used as an accurate and simple method of pertussis vaccine safety assessment.

平成16年9月厚生労働省は輸血前後の感染症マーカー検査の在り方について検討し, 「輸血療法の実施に関する指針」を一部改正した. その中で, 輸血前検査としてHBs抗原, HBs抗体, HBc抗体, HCV抗体, HCVコア抗原, HIV抗体を検査して感染の状況を把握し, 輸血後に“医師が感染リスクを考慮し, 感染が疑われる場合などに”HBV (NAT), HCVコア抗原, HIV抗体検査等を行う必要がある, としている. これを受けて日本輸血・細胞治療学会が運用マニュアルを作成した. (1) 輸血前に核酸増幅検査に耐えうる検体を凍結保存する. (2) 輸血前検査としてHBs抗原, HBs抗体, HBc抗体, HCV抗体, HCVコア抗原, HIV抗体を必要に応じて適宜施行する. (3) 輸血後3カ月後をめどに肝機能検査, HBs抗原, HCV抗体, HIV抗体を測定して感染を早期に発見することに努めるという内容である. 輸血後マーカー検査の実施率を高めるためには, 医師へのマニュアルの周知徹底と共に, 輸血前の患者へのインフォームドコンセントの際に輸血後感染症の説明をして輸血後検査を勧めることが必要である.

Human T-cell leukemia virus type I (HTLV-1) causes adult T-cell leukemia (ATL), a fatal T-cell leukemia resistant to chemotherapy, after more than 50 years of clinical latency from transmission through breast-feeding. Polyclonal expansion of virus-infected T cells predisposes them to transformation. Constitutive activation of nuclear factor-kappaB (NF-kappaB) in the leukemic cells is essential for their growth and survival. Blocking NF-kappaB has been shown to be a potential strategy to treat ATL. We tested this approach using a novel NF-kappaB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), and also examined its application to chemoprevention by selective purging of the HTLV-1-infected cells. DHMEQ inhibited NF-kappaB activation in primary ATL cells and cell lines derived from them and induced apoptotic cell death. NF-kappaB inhibition down-regulated expression of genes involved in antiapoptosis or cell-cycle progression. DHMEQ protected severe combined immunodeficiency (SCID) mice inoculated with HTLV-1-transformed cells from death. In addition, DHMEQ selectively targeted HTLV-1-infected cells in the peripheral blood of virus carriers in vitro, resulting in a decreased number of infected cells. We conclude that NF-kappaB is a potential molecular target for treatment and prevention of ATL. As a potent NF-kappaB inhibitor, DHMEQ is a promising compound allowing the translation of this strategy into clinical medicine.

Human T-lymphotropic virus type 1 (HTLV-1) is highly endemic in the Kyushu/Okinawa region of Japan. A nationwide investigation verified the frequency of HTLV-1 carriers among first-time blood donors and the occurrence of newly diagnosed adult T-cell leukemia/lymphoma (ATL) cases from 2007 through 2008. After adjusting for differences in capture rate between areas, the age-, sex- and area-specific incidence of ATL among carriers was determined. Annual ATL incidence among 10 000 carriers was 7.7 and 8.7 for the Kyushu and non-Kyushu/Okinawa regions, respectively. The incidence increased sharply for men from their 40s to their 70s, but the rate in females remained unchanged through their 40s to 70s. ATL incidence in middle-aged females was still low, even if female carrier frequency was assumed to be identical to that of males. Patients with ATL in their 60s and 70s will comprise two-thirds of all patients with ATL for the next 15 years in Japan.

Vaccines are beneficial and universal tools to prevent infectious disease. Thus, safety of vaccines is strictly evaluated in the preclinical phase of trials and every vaccine batch must be tested by the National Control Laboratories according to the guidelines published by each country. Despite many vaccine production platforms and methods, animal testing for safety evaluation is unchanged thus far. We recently developed a systems biological approach to vaccine safety evaluation where identification of specific biomarkers in a rat pre-clinical study evaluated the safety of vaccines for pandemic H5N1 influenza including Irf7, Lgals9, Lgalsbp3, Cxcl11, Timp1, Tap2, Psmb9, Psme1, Tapbp, C2, Csf1, Mx2, Zbp1, Ifrd1, Trafd1, Cxcl9, β2m, Npc1, Ngfr and Ifi47. The current study evaluated whether these 20 biomarkers could evaluate the safety, batch-to-batch and manufacturer-to-manufacturer consistency of seasonal trivalent influenza vaccine using a multiplex gene detection system. When we evaluated the influenza HA vaccine (HAv) from four different manufactures, the biomarker analysis correlated to findings from conventional animal use tests, such as abnormal toxicity test. In addition, sensitivity of toxicity detection and differences in HAvs were higher and more accurate than with conventional methods. Despite a slight decrease in body weight caused by HAv from manufacturer B that was not statistically significant, our results suggest that HAv from manufacturer B is significantly different than the other HAvs tested with regard to Lgals3bp, Tapbp, Lgals9, Irf7 and C2 gene expression in rat lungs. Using the biomarkers confirmed in this study, we predicted batch-to-batch consistency and safety of influenza vaccines within 2 days compared with the conventional safety test, which takes longer. These biomarkers will facilitate the future development of new influenza vaccines and provide an opportunity to develop in vitro methods of evaluating batch-to-batch consistency and vaccine safety as an alternative to animal testing.

Human T-cell leukemia virus type 1 (HTLV-1) can cause an aggressive malignancy known as adult T-cell leukemia/lymphoma (ATLL), as well as inflammatory diseases such as HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). We created a transgenic mouse model of HTLV-1 infection by using the distal promoter of Lck to express tax in mature thymocytes and peripheral T lymphocytes. Major phenotypes of disease in this model were mature T cell leukemia/lymphoma similar to ATLL and an inflammatory arthropathy. While expanding the transgenic mouse colony, we also found 2.7% of transgenic mice developed a HAM/TSP-like disease and 2.4% of transgenic mice developed a toxic epidermal necrolysis (TEN)-like disease. The HAM/TSP-like disease with symmetrical paraparesis of the hind limbs in transgenic mice was not inflammatory, unlike that found in HAM/TSP patients, but instead involved the invasion of histiocytic sarcoma cells into the lumbar spinal cord from the bone marrow where they had undergone extensive proliferation. Mice with the HAM/TSP-like disease showed abnormal expression of cytokines and chemokines, including TNF and IL-6. There are no reports of spontaneous symmetrical paraparesis caused by histiocytic sarcoma in mice. TEN is characterized by a rash, bullae, and diffuse exfoliation of wide cutaneous surface areas, as seen in second-degree burns. Massive keratinocyte apoptosis is the hallmark of TEN. The TEN-like disease in transgenic mice occurred mainly in C57BL/6 background strain mice. These mice showed a skin detachment rate of greater than 30%. The pathology in transgenic mice with a TEN-like disease is currently under study and will be discussed.

Twenty-three human T lymphotropic virus type I (HTLV-I) seroconverters were identified among 1120 HTLV-I‐seronegative adults followed up for 11 years in an area of Japan endemic for HTLV-I. The geometric mean titer of anti‐HTLV-I was 1:453 in the first year after seroconversion; the titer of each subject did not change significantly during 2‐10 years of followup. HTLV-I proviral DNA load was quantified in 15 seroconverters, and a broad range of levels was observed—from !10 to 11000 copies/10 5 peripheral blood mononuclear cells. However, there was no obvious change in HTLV-I proviral DNA load over several years within individual subjects. Therefore, both proviral DNA load and humoral response in adult HTLVI seroconverters were shown to stabilize within a few years after initial infection. In addition, 1 subject tested positive for HTLV-I proviral DNA before antibody seroconversion, which suggests the existence of a window period in community-acquired infection. Human T lymphotropic virus type I (HTLV-I) is a causative agent not only for adult T cell leukemia (ATL) but also for several other diseases, such as HTLV-I‐associated myelopathy/ tropical spastic paraparesis and HTLV-I uveitis [1‐6]. The major natural route of HTLV-I transmission in adults in Japan is thought to be sexual contact between spouses, especially from husband to wife [7, 8]. Newly acquired infection can be monitored by seroconversion of anti‐HTLV-I [9]. However, few reports are available about the early events in the natural history of incident HTLV-I infection in community-based populations. The Miyazaki Cohort Study (MCS) was established in 1984 for the primary purpose of investigating the natural history of HTLV-I infection [10]. Of the »2000 subjects enrolled in the cohort, 523 (26%) of 1974 subjects were positive for anti‐ HTLV-I at baseline. Among the anti‐HTLV-I‐negative subjects, a significant number of anti‐HTLV-I seroconversions

We previously demonstrated the increased provirus load in the peripheral blood of patients with human T‐cell leukemia virus type 1 (HTLV‐1) uveitis (HU). To delineate the relevance of the increased provirus load to clinical and immunologic parameters, we studied the correlation between them. Seventy‐nine HU patients (24 male and 55 female) were included in the study, with their informed consent. Plasma samples and genomic DNA of the peripheral blood mononuclear cells were isolated and the provirus load was estimated by semi‐quantitative polymerase chain reaction of the gag region sequence. Serum levels of anti‐HTLV‐1 antibodies and soluble IL‐2R were determined by electrochemiluminescence immuno assay and by ELISA, respectively. Disease activities were assessed and graded 0 to 4 according to the evaluation system. Recurrence of the disease during the follow‐up period was diagnosed ophthalmologically. The provirus load was significantly higher in the HU patients after Graves' disease (GD) than in those without GD (P

Genetic variability of the hepatitis B virus (HBV) constitutes one of the major challenges for diagnosis of HBV infection. It is plausible that amino acid substitutions in the "a" determinant of the HBV surface antigen (HBsAg) that affect antigenic sites, whether originating from genetic diversity or from mutations in the HBV strain itself, will affect the sensitivity of some diagnostic kits. In fact, recent studies have indicated that some diagnostic kits had false negative results with particular HBsAg mutants. There have been, however, few substantial studies evaluating sensitivities of diagnostic kits to the HBsAg encoded by different HBV genotypes. Our recent study found that 10 diagnostic kits available in Japan were able to detect HBsAg irrespective of whether it originated from HBV genotypes A, B or C, with the latter two genotypes being the dominant species in East Asia. In this study, we extended our previous efforts by assessing the ability of diagnostic kits to detect recombinant HBsAg derived from HBV genotypes A to H. Our results demonstrated that 9 out of 10 diagnostic kits evaluated were able to detect as low as 0.2 International Units (IU)/ml HBsAg, irrespective of HBV genotype. The genotypic differences in the HBV family thus appear to have little impact on the sensitivity of currently available HBsAg diagnostic kits.

Cutaneous T-cell lymphoma (CTCL) is a disease entity characterized by a primary sporadic T-cell proliferation in the skin. Human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes adult T-cell leukemia/lymphoma. Recently, several authors have detected the HTLV-1 genome in genomic DNA from patients with CTCL and proposed a causal relation of HTLV-1 to CTCL. However, it remains controversial because these studies contain some problems in materials used to detect HTLV-1. We investigated both fresh and cultured T lymphocytes (128 specimens) derived from 50 Japanese patients with CTCL, where HTLV-1 is endemic, by using polymerase chain reaction with four sets of primers including gag,pol,env, and pX regions of HTLV-1 to elucidate the relationship between HTLV-1 and CTCL in Japan. However, none of the 128 DNA specimens revealed positive for HTLV-1 in contrast to the previous studies. We conclude that CTCL, which does not include HTLV-1, is present although the pathogenesis of CTCL may be different by areas or races. © 1997 by The American Society of Hematology.

A 53-year-old female infected with human T lymphotropic virus type-I (HTLV-I) suffered from chronic renal failure, aplastic anemia, myelopathy, uveitis, Sjögren's syndrome and Weber-Christian disease. Although HTLV-I antibody was negative in cerebrospinal fluid, she was diagnosed as HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) based on clinical and histological findings. Though to date there is no direct evidence, other complications have also been reported to be HTLV-I related diseases. This case provided the unique opportunity to observe various HTLV-I related diseases.

Adult T-cell leukemia (ATL) was first reported in Japan, where it has a high incidence in the southwestern region. The retrovirus, human T-lymphotropic virus type I (HTLV-I), is found to be the causative agent of ATL. In ATL-endemic areas, the rate of HTLV-I carriers is high. A definite diagnosis of ATL is based on the presence of HTLV-I proviral DNA in the tumor cell DNA. ATL cells originate from the CD4 subset of peripheral T cells. ATL shows diverse clinical features but can be divided into four subtypes: the acute, chronic, smoldering, and lymphoma types. Chemotherapy is not effective; the acute and lymphoma types have a poor prognosis. Familial occurrence of ATL is common. HTLV-I infection is caused by transmission of live infected lymphocytes from mother to child, or from man to woman, or by blood transfusion.

Human T-cell lymphotropic virus type I (HTLV-I) is known to cause adult T-cell leukemia/T-cell lymphoma and tropical spastic paraparesis/HTLV-I-associated myelopathy. Recent seroepidemiologic, clinical, and virologic studies indicate that the virus is also related to a certain type of uveitis, which has been classified as uveitis without defined etiologies or idiopathic uveitis. According to the seroepidemiologic survey, the seroprevalence of HTLV-I in patients with idiopathic uveitis was significantly higher than that of two control groups, that is, patients with uveitis with defined etiologies and patients with nonuveitic ocular diseases. Clinically, the uveitis seen in HTLV-I carriers is characterized by moderate to severe cellular infiltration in the eye and by moderate retinal vasculitis, and the intraocular inflammation responds well to corticosteroid therapy. Interestingly, 25% of female patients with the disease had a previous history of Graves disease with hyperthyroidisms. The following virologic, molecular biologic findings suggest that cytokines produced by HTLV-I-infected T cells in the eye play the central role in the pathogenic mechanisms of the uveitis: (a) the virus load in the peripheral blood monocytes analyzed by the quantitative polymerase chain reaction methods was significantly greater in patients with the uveitis than in asymptomatic carriers, (b) the proviral DNA of HTLV-I and the gene expression of the virus at the mRNA level was detected in the infiltrating cells from the eyes of the patients, (c) the virus particles were detected by electron-microscopic examination in the T-cell clones established from the intraocular fluid of the patients, and (d) the HTLV-I-infected T cells produced a variety of cytokines without any stimuli, such as interleukin (IL)-1 alpha, IL-2, IL-3, IL-6, IL-8, IL-10, tumor necrosis factor alpha, interferon-gamma, and granulocyte-macrophage colony-stimulating factor. Based on the seroepidemiologic, clinical, and virologic data, the uveitis seen in HTLV-I carriers is considered to be a distinct clinical entity related to HTLV-I infection, and the disease is designated as HTLV-I uveitis.

L-selectin is an adhesion molecule of the selectin family that mediates the initial step of leukocyte adhesion to vascular endothelium. Upon cellular activation, expression of the L-selectin gene is downregulated at both the protein and mRNA levels. To understand the mechanism of leukemic cell infiltration into organs, we studied the expression and regulation of L-selectin mRNA in fresh leukemic cells of adult T-cell leukemia (ATL) patients and investigated the response of the L-selectin promoter to human T-cell lymphotropic virus type 1 (HTLV-1) Tax, which is a viral transcriptional transactivator. Flow cytometry showed that L-selectin was expressed on fresh ATL cells along with other activation antigens. Northern blot analysis showed that ATL cells overexpressed that L-selectin mRNA and that the level was aberrantly upregulated after PMA stimulation. Studies using in situ hybridization showed expression of the L-selectin mRNA in the infiltrating leukemic cells in the liver of two ATL patients. Intravenous injection of a rat T-cell line that overexpresses L-selectin showed increased organ infiltration. The induction of Tax expression in JPX9 cells resulted in about a twofold increase in the mRNA expression levels compared with the basal level. Chloramphenicol acetyltransferase (CAT) assay after transient cotransfection showed about a fivefold transactivation of the L-selectin promoter by Tax. The serum level of the shed form of L-selectin was significantly increased in ATL patients (mean +/- SD, 4,215.4 +/- 4,111 ng/mL) compared with those of asymptomatic carriers and healthy blood donors (mean +/- SD, 1,148.0 +/- 269.0 ng/mL and 991.9 +/- 224 ng/mL, respectively). These results indicated that ATL cells constitutively overexpress the L-selectin gene that can be transactivated by HTLV-1 Tax. The overexpression of L-selectin, as well as of inflammatory cytokines, by ATL cells may provide a basis for ATL cells to attach the vascular endothelium, leading to transmigration and organ infitration.

The human T-lymphotropic virus type I (HTLV-I) carrier rates for blood donors in Kumamoto, Kyushu, Japan for 8 years, 1986-1993, are currently available. The data show that 16-19-year-olds in 1986 and 20-29-year-olds in 1993 represent nearly the same cohort, because the median age in both groups is 24.5 years in 1993. Therefore, comparison of the HTLV-I positive rate for the two groups gives an estimate of the change in the rate over 7 years within the cohort. In males, 265 of 22,143 donors (1.20%) were seropositive for HTLV-I among 16-19-year-olds in 1986, and 214 were seropositive among 20,076 (1.07%) donors in 20-29-year-olds in 1993. In females, 203 were seropositive among 20,677 (0.98%) donors in 16-19-year-olds in 1986, and there 154 were seropositive among 18,660 (0.83%) donors in 20-29-year-olds in 1993. Thus, the seropositive rates declined in both sexes. However, the average annual rate of immigration to Kumamoto Prefecture was 2.37%. If seropositive rates for 20-29-year-olds in 1993 are adjusted for the dilution effect due to immigration (under the assumption that all immigrants were HTLV-I negative), the adjusted carrier rate for males is 1.26% and that for females is 0.98%. The adjusted carrier rates for both sexes are almost the same as those for 16-19-year-olds in 1986. This indicates that horizontal transmission was negligible for those in the cohort who were in their early reproductive period. Using all 8 year carrier rates for 16-19-year-olds and 20-29-year-olds, chronological changes of 20-29-year-olds, in the near future was estimated. The best goodness of fit model indicated that the HTLV-I carrier rate will decline exponentially, and that the rate will decrease by 50% approximately every 10 years for both sexes. It is probable that in recent years south-west Japan has lost the conditions that are favorable for HTLV-I endemicity and the virus will be virtually non-endemic within a few generations.

Adult T-cell leukemia (ATL) is an aggressive T-cell malignancy caused by human T-cell leukemia virus type I (HTLV-1) infection and often occurs in HTLV-1-endemic areas, such as southwestern Japan, the Caribbean islands, Central and South America, Intertropical Africa, and Middle East. To date, many epidemiological studies have been conducted to investigate the incidence of ATL among general population or HTLV-1 carriers and to identify a variety of laboratory, molecular, and host-specific markers to be possible predictive factors for developing ATL because HTLV-1 infection alone is not sufficient to develop ATL. This literature review focuses on the epidemiology of ATL and the risk factors for the development of ATL from HTLV-1 carriers, while keeping information on the epidemiology of HTLV-1 to a minimum. The main lines of epidemiological evidence are: (1) ATL occurs mostly in adults, at least 20–30 years after the HTLV-1 infection, (2) age at onset differs across geographic areas: the average age in the Central and South America (around 40 years old) is younger than that in Japan (around 60 years old), (3) ATL occurs in those infected in childhood, but seldom occurs in those infected in adulthood, (4) male carriers have about a 3–5 fold higher risk of developing ATL than female, (5) the estimated life-time risk of developing ATL in HTLV-1 carriers is 6–7% for men and 2–3% for women in Japan, (6) a low anti-Tax reactivity, a high soluble interleukin-2 receptor level, a high anti-HTLV-1 titer, and high levels of circulating abnormal lymphocytes and white blood cell count are accepted risk factors for the development of ATL, and (7) a higher proviral load (more than 4 copies/100 peripheral blood mononuclear cells) is an independent risk factor for progression of ATL. Nevertheless, the current epidemiological evidence is insufficient to fully understand the relationship between HTLV-1 infection and ATL. Further well-designed epidemiological studies are needed.

Adult T-cell leukemia (ATL) is neoplasm of the mature helper T lymphocytes and human T-cell lymphotropic virus type-I (HTLV-I) has been shown to be causative virus of ATL. Because HTLV-I integrates its provirus randomly into host chromosomal DNA, monoclonal integration of HTLV-I provirus indicates the clonal proliferation of HTLV-I-infected cells. Therefore, demonstration of clonality of HTLV-I proviral DNA is essential to diagnosis of ATL. Southern blot analysis was used for this purpose. We developed the novel method using inverse polymerase chain reaction (IPCR) to detect the clonality of HTLV-I proviral DNA. This method identified the clonality in all ATL cases. Diagnosis could be made within 3 days using this method. It enabled us to detect specifically the presence of minimal numbers of ATL cells with high sensitivity. It also identified the monoclonal or oligoclonal proliferations of HTLV-I-infected cells in HTLV-I carriers and the intermediate state, in which no clonality could be shown by conventional Southern blot analyses. This finding indicated that even HTLV-I carriers had monoclonal proliferation of HTLV-I-infected cells without any symptoms. This novel method is shown to be useful for the diagnosis of ATL and provides information on the natural course of HTLV- I infection.

A distinct clinical entity of uveitis associated with human T lymphotropic virus type 1 (HTLV-I) has been reported previously. During the period between January 1989 and April 1992, 93 patients were observed with HTLV-I uveitis and a significant correlation was found between Graves' disease and HTLV-I uveitis. Sixteen of the 93 patients with HTLV-I uveitis (17.2%) had a previous history of Graves' disease. Fifteen patients were female (15/60, 25.0%) and one was male (1/33, 3.0%). Interestingly, uveitis occurred after the onset of Graves' disease in all cases. On the other hand, none of 222 patients with idiopathic uveitis who were seronegative to HTLV-I had a history of Graves' disease. Although the mechanisms by which HTLV-I causes the correlation between uveitis and Graves' disease are unknown, the present data suggest that immune mediated or autoimmune mechanisms are involved in HTLV-I uveitis.

Adult T-cell leukaemia (ATL) was first reported in Japan, where it has a high incidence in the southwest region. The retrovirus human T-lymphotropic virus type I (HTLV-I) is the cause of ATL; and in ATL-endemic areas, the rate of carriage of antibodies to HTLV-I is high. A definite diagnosis of ATL is based on the presence of HTLV-I proviral DNA in the tumour-cell DNA. ATL cells originate from the CD4 subset of peripheral T cells. ATL shows diverse clinical features but can be divided into four subtypes--acute, chronic, smouldering, and lymphoma type. It is resistant to chemotherapy, and the acute and lymphoma types have a poor prognosis. Familial occurrence of ATL is common. HTLV-I infection is caused by transmission of live infected lymphocytes from mother to child, from man to woman, or by transfusion. Infection with HTLV-I can lead to other diseases, including HTLV-I-associated myelopathy/tropical spastic paraparesis and HTLV-I uveitis, possibly via induction of immunodeficiency or hyperreactivity against HTLV-I-infected cells.

The hypothesis that HTLV-1 uveitis, a recently identified disease entity associated with human T-cell leukemia virus type I (HTLV-1), is caused by a specific subtype of the virus was tested. The nucleotide sequences of the long terminal repeat of HTLV-1 from five patients with HTLV-1 uveitis (HU) and four with adult T-cell leukemia were phylogenetically analyzed. Our results showed that both subtypes which had been identified in Japan were associated with HU, indicating that there was no difference in pathogenicity between these phylogenetic subtypes. One of the subtypes was more frequently isolated in Okinawa than in Kyushu, suggesting a bias in the prevalence of each subtype among the inhabitants of these two areas of Japan.

Although crucial roles of microRNA have begun to emerge, detailed studies with ATL patients have not been achieved. Using 40 primary ATL samples and 22 samples of normal CD4+ T-cells, we determined the microRNA signatures of ATL and revealed loss of miR-31, which has recently been reported as a metastasis-associated miRNA. All ATL cases invariably showed undetectable or very low levels of miR-31, clearly implying that miR-31 loss is involved in ATL development. As a novel miR-31 target gene, we identified NF-κB inducing kinase (NIK) that plays central roles in noncanonical signaling and constitutive activation of NF-κB in various cancers, including ATL. Restoration of miR-31 downregulated the levels of NIK and NF-κB activity, resulting in reduction of malignant phenotypes, containing proliferative index, anti-apoptosis, and chemotaxis in ATL cells. Furthermore, lentivirus-introduced miR-31 could induce strong apoptosis in primary tumor cells freshly isolated from ATL patients, indicating pivotal functions of miR-31 as a tumor suppressor. Global copy number profiling demonstrated that 21 cases out of 168 (12.5%) have genomic loss of 9p21 containing miR-31 region. Furthermore, expression profiling and ChIP assay showed requirement of overexpression of histone methyltransferase in epigenetic suppression of miR-31 and aberrant NF-κB activation in primary ATL cells. Knockdown of methyltransferase complex restored the miR-31 expression and consequently inhibited NIK-dependent NF-κB cascade. These findings illustrated that genetic and epigenetic abnormalities link to NF-κB activation through the loss of miR-31. Considering aberrant epigenomics associated with cancers, the emerging relationship provides us a conceptual advance in understanding the broad-acting oncogenic signaling.

Hepatitis C virus (HCV) has been recognized as a major cause of chronic liver diseases worldwide. It has been suggested that HCV infects not only hepatocytes but also mononuclear lymphocytes including B cells that express the CD81 molecule, a putative HCV receptor. HCV infection of B cells is the likely cause of B-cell dysregulation disorders such as mixed cryoglobulinemia, rheumatoid factor production, and B-cell lymphoproliferative disorders that may evolve into non-Hodgkin's lymphoma (NHL). Epidemiological data indicate an association between HCV chronic infection and the occurrence of B-cell NHL, suggesting that chronic HCV infection is associated at least in part with B-cell lymphomagenesis. In this paper, we aim to provide an overview of recent literature, including our own, to elucidate a possible role of HCV chronic infection in B-cell lymphomagenesis.

Adult T cell leukaemia-lymphoma (ATL) was first discovered and reported in Japan, where it has a high incidence in the south-west region. The first human retrovirus HTLV-I (human T-cell lymphotropic virus type I) is considered to be related to its aetiology. In ATL endemic areas, HTLV-I carriers form a fairly high percentage of the population, even among healthy individuals. ATL shows diverse clinical features. It can be divided into four subtypes: acute, chronic, smouldering and lymphoma type. ATL cells originate from the CD4-positive subset of peripheral T cells; they show a characteristic notch in the nucleus and a tendency to lobulation. ATL resists chemotherapy, and patients with acute and lymphoma types have a fairly poor prognosis. A definite diagnosis of ATL is made by documenting the presence of HTLV-I proviral DNA in the DNA of tumour cells. HTLV-I infection is caused by transmission of live lymphocytes via three routes (from mother to child, from males to females, and by transfusion). Familial occurrence of ATL is frequently seen. HTLV-I infection is seen in other countries, but its incidence is highest in Japan. Infection with HTLV-I is a direct cause of ATL. Furthermore, infection with this virus can indirectly cause many other diseases via the induction of immunodeficiency, such as chronic lung disease, opportunistic lung infection, cancer of other organs, monoclonal gammopathy, chronic renal failure, strongyloidiasis, non-specific dermatomycosis, HTLV-I-associated lymphadenitis, HTLV-I uveitis and HTLV-I-associated myelopathy-tropical spastic paraparesis (HAM/TSP).

Seven hundred and twenty‐three serum samples from individuals in 13 Gidra‐speaking villages in Western Province, Papua New Guinea were tested for evidence of infection with human T‐ lymphotropic virus type I (HTLV‐I), human immunodeficiency virus type I (HIV‐I), hepatitis B virus (HBV) and hepatitis C virus (HCV). No samples were positive for antibodies to HIV‐I. Antibodies to HTLV‐I were found in 13 samples (1.8%), HBV surface antigens (HBsAg) were found in 86 samples (11.9%), and antibodies to HCV were found in 30 samples (4.1%). Six (46.2%) of 13 HTLV‐I positive samples were positive for HCV or HBsAg. The seropositive rate varied in different villages and the incidence of HTLV‐I and HCV was higher in coastal and riverine areas than inland.

Our recent study indicated that peripheral B cells in chronic hepatitis C (CHC) patients were infected with hepatitis C virus (HCV). It was also demonstrated that the frequency of CD27(+) B cells, i.e. memory phenotype, was significantly reduced in the peripheral blood of CHC patients. An assumption was made by these findings that the CD27(+) B cells are susceptible to apoptosis when infected with HCV. Therefore, in this study, the susceptibility of CD27(+) B cells to apoptosis in CHC patients was analyzed. Contrary to our assumption, it was found that CD27(+) B cells are more resistant to apoptosis than the counterpart subset, i.e. CD27(-) B cells. The rationale for this finding is discussed with regard to the possible role for memory B cells as an HCV reservoir for persistent infection in CHC patients.

Endotoxin contamination is a serious threat to the safety of parenteral drugs, and the rabbit pyrogen test has played a crucial role in controlling this contamination. Although the highly sensitive endotoxin test has replaced the pyrogen test for various pharmaceuticals, the pyrogen test is still implemented as the control test for most blood products in Japan. We examined the applicability of the endotoxin test to blood products for reliable detection and quantification of endotoxin. Nineteen types of blood products were tested for interfering factors based on spike/recovery of endotoxin by using 2 types of endotoxin-specific lysate reagents for photometric techniques. Interfering effects on the endotoxin test by the products could be eliminated by diluting from 1/2 to 1/16, with the exception of antithrombin III. However, conventional lysate reagents that also react with non-pyrogenic substances, such as (1-3)-β-D-glucan, produced results that were not relevant to endotoxin content or pyrogenicity. Our results showed that the endotoxin test would be applicable to most blood products if used with appropriate endotoxin-specific lysate reagents.

Using an enzyme-linked immunosorbent assay (ELISA), we measured the levels of neuron-specific enolase (NSE) in the sera of 100 normal controls, 31 patients with adult T cell leukaemia (ATL), 13 patients with acute lymphoblastic leukaemia (ALL), 19 patients with acute non-lymphoblastic leukaemia (ANLL) and 17 patients with human T lymphotropic type I (HTLV-I) associated myelopathy (HAM). Levels higher than 5 ng/ml were considered as positive for NSE, since this value was almost 2 standard deviations (S.D) above the mean of normal controls. The rates of positive NSE levels were 55 percent in patients with ATL, 54 percent in patients with ALL, 11 percent in patients with ANLL and 0 percent in patients with HAM. High NSE levels fell to near normal levels in patients with ATL and ALL responding to cytotoxic therapy. It is concluded from these results that NSE may be a useful tumour marker for lymphoid malignancies.

PurposeKW-0761, a defucosylated humanized anti-CC chemokine receptor 4 (CCR4) antibody, exerts a strong antibody-dependent cellular cytotoxic effect. This phase I study assessed the safety, pharmacokinetics, recommended phase II dose and efficacy of KW-0761 in patients with relapsed CCR4-positive adult T-cell leukemia-lymphoma (ATL) or peripheral T-cell lymphoma (PTCL).Patients and MethodsSixteen patients received KW-0761 once a week for 4 weeks by intravenous infusion. Doses were escalated, starting at 0.01, 0.1, 0.5, and finally 1.0 mg/kg by a 3 + 3 design.ResultsFifteen patients completed the protocol treatment. Only one patient, at the 1.0 mg/kg dose, developed grade 3 dose-limiting toxicities, skin rash, and febrile neutropenia, and grade 4 neutropenia. Other treatment-related grade 3 to 4 toxicities were lymphopenia (n = 10), neutropenia (n = 3), leukopenia (n = 2), herpes zoster (n = 1), and acute infusion reaction/cytokine release syndrome (n = 1). Neither the frequency nor severity of toxicities increased with dose escalation. The maximum tolerated dose was not reached. Therefore, the recommended phase II dose was determined to be 1.0 mg/kg. No patients had detectable levels of anti-KW-0761 antibody. The plasma maximum and trough, and the area under the curve of 0 to 7 days of KW-0761, tended to increase dose and frequency dependently. Five patients (31%; 95% CI, 11% to 59%) achieved objective responses: two complete (0.1; 1.0 mg/kg) and three partial (0.01; 2 at 1.0 mg/kg) responses.ConclusionKW-0761 was tolerated at all the dose levels tested, demonstrating potential efficacy against relapsed CCR4-positive ATL or PTCL. Subsequent phase II studies at the 1.0 mg/kg dose are thus warranted.

Seroepidemiologic, clinical, and virologic studies were performed to determine whether human T-cell lymphotropic virus type I was closely associated with uveitis in two hospitals. One hospital was in an endemic area of the virus (Miyakonojo, Miyazaki) and the other hospital was in a less endemic area (Kurume). In the endemic area, the seroprevalence of the virus in patients with uveitis without defined causes (35.4%, 62 of 175 patients) was significantly higher than that in patients with nonuveitic ocular diseases (16.1%, 42 of 261 patients), or in patients with uveitis with defined causes (10.3%, eight of 78 patients). The seroprevalence in younger patients (20 to 49 years of age) with uveitis without defined causes in the area was 44.8% (30 of 67 patients), whereas it was only 9.3% (ten of 107 patients) in the other two groups. A similar observation was recorded even in the less endemic area (Kurume). Because the seroprevalence of the virus in the general population is known to be low in younger patients and to increase with age, these findings were interpreted to indicate that the association of human T-cell lymphotropic virus type I with uveitis was significant. Most patients, particularly those aged 20 through 49 years, had an intermediate uveitis characterized by a moderate inflammation in the vitreous body accompanied by an iritis and retinal vasculitis. The ocular symptoms in the patients differed from those of other types of uveitis common in Japan (Behcet's disease, Vogt-Koyanagi-Harada's disease, and toxoplasmosis, for example). Although the symptoms of uveitis are somewhat similar to those in sarcoidosis, none of the patients had any systemic evidence of sarcoidosis. Moreover, the proviral DNA of human T-cell lymphotropic virus type I was detected by polymerase chain reaction by using pol region primers from the inflammatory cells in the anterior chamber in seven of nine seropositive patients with the uveitis, but not in all tested patients with other types of uveitis. These data thus indicate that the uveitis is highly associated with human T-cell lymphotropic virus type I and is a distinct clinical entity.

Seroepidemiological, clinical and virological studies were carried out in an HTLV-I endemic area to find out if HTLV-I caused an intraocular inflammatory disorder, uveitis. The seroprevalence in patients with uveitis without defined etiologies (62/175, 35.4%) was significantly higher than that in patients with non-uveitic ocular diseases (42/261, 16.1%) or in patients with uveitis with defined etiologies (8/78, 10.3%). Moreover, the seroprevalence in young adults (20–49 years) with uveitis without defined etiologies was 30/67 (44.8%), whereas it was only 10/107 (9.3%) in the other two groups. The uveitis in HTLV-I carriers was characterized clinically by a moderate inflammation of the vitreous body accompanied by a mild iritis and retinal vasculitis. The proviral DNA of HTLV-I was detected by polymerase chain reaction from the inflammatory cells in the anterior chamber in 9 out of 9 seropositive patients with the uveitis, but not in any of the tested patients with other types of uveitis. These data, thus, indicate that HTLV-I causes a specific type of intraocular inflammation, uveitis.

Epidemiological data have indicated a close relationship between chronic HCV infection and non-Hodgkin’s B-cell lymphoma (B-NHL). In this study, functional phenotypes and gene expression profiles of PBMCs were analyzed in chronic hepatitis C (CHC) patients who developed B-NHL. The frequencies of effector CD8 + T cells and cytotoxic natural killer cells increased in CHC patients with B-NHL compared to those in CHC patients without B-NHL. These phenotypic changes may reflect the host’s immune response to neoplasia. The mRNA expression levels of several oncogenes increased in CHC patients without B-NHL, but were much higher in CHC patients with B-NHL, while mRNA levels of type I IFNs were decreased in CHC patients without B-NHL and were nearly negligible in CHC patients with B-NHL. Interestingly, the mRNA expression levels of activation-induced cytidine deaminase and caspase recruitment domain-containing proteins markedly increased in CHC patients without B-NHL but decreased in CHC patients with B-NHL. These results are discussed in view of the possible involvement of HCV infection in B-cell lymphomagenesis.

A body of evidence has suggested a close link between chronic hepatitis C virus (HCV) infection and B cell abnormalities, including mixed cryoglobulinemia, rheumatoid factor (RF) production, and lymphoproliferative disorders that may develop into non-Hodgkin's lymphoma. Recent studies have demonstrated the expansion of CD5(+) B cells in the peripheral blood of chronic hepatitis C patients (CHC). As CD5(+) B cells, which are capable of producing autoantibodies and RF, are apparently crucial for the development of HCV-associated pathogenesis, the fate of both the CD5(+) and CD5(-) B cell subsets upon chronic HCV infection is of interest. In this study, the degree to which chronic HCV infection induces apoptosis in each B cell subset was investigated. Our results demonstrated that peripheral CD5(-) B cells were more susceptible to apoptosis than CD5(+) B cells in CHC. Furthermore, plasma levels of IL-4, IL-10, and IL-12 were significantly elevated in CHC, thus suggesting that these interleukins protect CD5(+) B cells from apoptosis. The rationale for the differential susceptibility of distinct B cell subsets in CHC is also discussed with regard to extrahepatic manifestations associated with chronic HCV infection.

Epidemiological data indicate a close relationship between chronic hepatitis C virus (HCV) infection and B-cell non-Hodgkin's lymphoma (B-NHL), suggesting that chronic HCV infection is, at least in part, associated with B-lymphomagenesis. However, experimental data concerning these conditions remains elusive. In this study, we confirmed that peripheral blood B cells of chronic hepatitis C (CHC) patients were infected with HCV. Expression levels of activation-induced cytidine deaminase (AID) which are thought to be associated with occurrence of B-NHL were analyzed in these CHC B cells. It was demonstrated that AID mRNA/protein levels in CHC B cells were dramatically increased compared with those of healthy subjects. Furthermore, expression levels of several previously reported prognostic B-NHL marker genes in the B cell subset of CHC patients were increased. These results suggest a possible relationship between chronic HCV infection and B-lymphomagenesis.

Megakaryopoiesis is associated with inflammatory reactions. To investigate the role of interferon regulatory factors (IRFs) in inflammation-associated megakaryopoiesis, mouse bone marrow hematopoietic stem cells (HSCs) were analyzed. IFN-γ treatment induced IRF-2 expression as well as the expression of CD41 and IRF-1 in HSCs. An in vitro clonogenic assay showed that IRF-2- but not IRF-1-overexpressing cells increased the number of megakaryocytic colonies. IRF-2 transfection up-regulated CD41 promoter activity in hematopoietic cell lines. The number of CD41-positive bone marrow cells increased in mice injected with IRF-2-expressing bone marrow cells. These findings suggest that IRF-2 plays an important role in megakaryopoiesis in inflammatory states.

Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-lymphocytic malignancy associated with a retrovirus designated human T-cell lymphotropic virus type I (HTLV-1). The diversity in clinical features and prognosis of patients with this disease has led to its subclassification into the following four categories: acute, lymphoma, chronic, and smoldering types. The chronic and smoldering subtypes are considered indolent and are usually managed with watchful waiting until disease progression, analogous to the management of some patients with chronic lymphoid leukemia (CLL) or other indolent histology lymphomas. Patients with aggressive ATL generally have a poor prognosis because of multidrug resistance of malignant cells, a large tumor burden with multiorgan failure, hypercalcemia, and/or frequent infectious complications as a result of a profound T-cell immunodeficiency. Under the sponsorship of the 13th International Conference on Human Retrovirology: HTLV, a group of ATL researchers joined to form a consensus statement based on established data to define prognostic factors, clinical subclassifications, and treatment strategies. A set of response criteria specific for ATL reflecting a combination of those for lymphoma and CLL was proposed. Clinical subclassification is useful but is limited because of the diverse prognosis among each subtype. Molecular abnormalities within the host genome, such as tumor suppressor genes, may account for these diversities. A treatment strategy based on the clinical subclassification and prognostic factors is suggested, including watchful waiting approach, chemotherapy, antiviral therapy, allogeneic hematopoietic stem-cell transplantation (alloHSCT), and targeted therapies.

CAEBV is a high mortality and morbidity disease with life-threatening complications. Nevertheless, the treatment regimens for CAEBV have not yet been established. Although some reports have described CAEBV therapy involving treatments such as antiviral drugs, immunomodulatory agents, and immunochemotherapy, none of these treatments have been demonstrated to be effective. The only treatment reported to be effective is allogeneic SCT. However, the complications of SCT are severe, so treatment results have been poor. Recently, immunotherapy has been devised, but this is still in the developmental stage. In this report, two cases of CAEBV in which allogeneic SCT was performed soon after diagnosis are reported. In both cases, a high EBV genome titer in the peripheral blood was detected at onset. After SCT, the EBV genome titer decreased as CTL activity gradually increased. This fact suggested that not only high-dose chemotherapy as a preconditioning treatment of SCT but also increased CTL activity which could eliminate virus-infected cells might be effective, although additional cases should be studied in order to establish effective treatments.

SUMMARYThe cell surface expression of low-affinity Fc epsilon receptor (FceRII), which is identical to CD23, and the serum levels of IgE binding factors (IgE BFs), a soluble form of FceRII, and IgE were investigated in HTLV-I-infected individuals, and the results were compared with those for HTLV-I-negative controls. The occurrence of FcεRII+ mononuclear cells did not differ among the blood samples from the HTLV-I-infected groups; however, the levels of serum IgE BFs were significantly decreased (P