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 follow-up. HTLV-I proviral DNA load was q...

The prevalence of human T-cell lymphotropic virus (HTLV-1/2) infection among puerperae in the State of Mato Grosso, Brazil, is unknown. Through this cross-sectional study, the prevalence of HTLV-1/2 infection among puerperae attended at three public maternity hospitals in Cuiabá, State of Mato Grosso, was defined. Between April and September 2006, 3,831 deliveries took place and 2,965 puerperae...

It has been shown that interleukin 4 (IL-4) stimulates the proliferation of cells from patients affected by adult T-cell leukaemia, the haematological malignancy aetiologically associated with human T-lymphotropic virus type I (HTLV-I). In the present study, human neonatal lymphocytes were exposed to HTLV-I in vitro in the presence of IL-4. The results showed that: (i) cultures exposed to HTLV-...

To investigate serological, epidemiological, and molecular aspects of HTLV-1, HTLV-2, and HIV-1 infections in Amerindian populations in Brazil, we tested 683 and 321 sera from Tiriyo and Waiampi Indians, respectively. Both HIV-1 and HTLV-2 infections were detected at low prevalence among the Tiriyos whereas only HTLV-1 was present among the Waiampis, also at low prevalence. Analysis of the nucl...

Reported at the beginning of the 1980s, Human T lymphotropic viruses type 1 and 2 (HTLV1, HTLV 2) were the first retroviruses to have been detected in human beings. HTLV 1 was isolated from adult T-cell leukemia (ATL) and first described by Takatsuki et al. in Japan in 1976, as a malignancy that only affects T cells and only in adults (1, 2). Albeit infrequent, HTLV-1 infection may lead to seve...

The main mode of mother-to-child transmission the human T-cell leukemia virus (HTLV)-1 is through breastfeeding. Although most reliable nutritional regimen to prevent HTLV-1 exclusive formula feeding, a recent meta-analysis revealed that short-term breastfeeding within 90 days does not increase risk infection. protocol Japanese Health, Labor, and Welfare Science Research Group primarily recomme...

BACKGROUND We investigated behavioural and environmental risk factors for seropositivity to human T-lymphotropic virus type I (HTLV-I). METHODS A nested case-control study of 201 HTLV-I seropositive subjects and 225 age- and sex-matched seronegative controls was performed using questionnaire data from the enrollment visit of a cohort study in 1987-1988. HTLV-I serostatus was confirmed using e...

A number of non-human-immunodeficiency-virus (HIV) type 1 disorders are associated with CD4+ T-cell deficiency and dysfunction. However, the etiopathogenesis of CD4+ T-cell immunodeficiency in these disease states remains unclear. Human intracisternal retroviral (HICRV) particles were detected in a lymphoblastoid cell line exposed to mononuclear cells from a patient with severe CD4+ T-cell defi...

Human T cell leukemia virus (HTLV), which we previously called adult T cell leukemia virus (ATLV), is a possible causative agent of human adult T cell leukemia (ATL) (1). Since the HTLV genome was demonstrated not to contain a typical v-onc gene (2) and the HTLV proviral genome is integrated into random sites in cellular DNA of leukemia cells in each ATL patient (3), the mechanism of HTLV-induc...

The major route of human T-cell leukemia virus type 1 (HTLV-1) infection is mother-to-child transmission caused by breast-feeding. We investigated the host immune responses to orally established persistent HTLV-1 infection in adult rats. HTLV-1-producing MT-2 cells were inoculated into immunocompetent adult rats either orally, intravenously, or intraperitoneally. HTLV-1 proviruses were detected...