International Journal of Hematology

, Volume 76, Supplement 2, pp 240–245 | Cite as

Human T lymphotropic virus type-I and adult T-cell leukemia in Japan

  • Kazunari Yamaguchi
  • Toshiki Watanabe
Safety Issues in Blood & Blood Products Transfusion


HTLV-I is the first retrovirus to be associated directly with human malignancy. In ATL-endemic areas, the rate of HTLV-I carriers is high. Both HTLV-I and ATL have been shown to be endemic in some regions of the world, especially in southwest Japan, the Caribbean islands, South Americas, and parts of Central Africa. Antibodies against HTLV-I have been found in over one million individuals, and more than 700 cases of ATL have been diagnosed each year in Japan alone. The cumulative incidence of ATL among HTLV-I carriers in Japan is estimated at 2.5% (3–5% in males, 1–2% in females). In endemic areas, HTLV-I Ab were found in the sera of 6 to 37 percent of healthy adults over 40 years of age. This clustering is thought to be due to the limited transmission of virus between socially isolated populations. The diagnostic criteria for HTLV-I associated ATL have been defined as follows. 1) Histologically and/or cytologically proven lymphoid malignancy with T cell antigens. 2) Abnormal T-lymphocytes present in the peripheral blood, except in the lymphoma type. 3) Serum specimens for all patients with ATL have HTLV-I Ab. 4) Demonstration of clonality of HTLV-I proviral DNA is a definite diagnosis of ATL. ATL shows diverse clinical features but can be divided into four subtypes: acute, chronic, smoldering, and lymphoma type. The pattern of HTLV-I transmission is through one of three different modes. Infected mothers can transmit the virus to newborns mainly via breast milk. The virus also can be transmitted from male to female by sexual intercourse, and through blood transfusion. Chemotherapy is not effective; the acute and lymphoma types have a poor prognosis. ATL is generally treated with curative intent using combination chemotherapy, although long-term success has been very limited. Unfortunately that advance did not translate into an improvement in the overall survival; the median remain 10 months. In contrast, smoldering ATL, or some cases of chronic ATL, may have a more protracted natural course, which may be compromised by aggressive chemotherapy. Alternative strategies for both acute and chronic forms are clearly needed. After infection of HTLV-I, there is a long latent period before onset of ATL. Analyses by PCR showed that clearly proliferation occurred in intermediate state or even carriers with high virus load. Such clonal proliferation might be preleukemic stage, which suggested that carriers with high virus load should be risk group to have ATL.


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  1. 1.
    Yamaguchi K. Human T-lymphotropic virus type I in Japan.Lancet. 1994;343:213–216.PubMedCrossRefGoogle Scholar
  2. 2.
    Inaba S, Okochi K, Sato H, et al. Efficacy of donor screening for HTLV-I and the natural history of transfusion-transmitted infection.Transfusion. 1999;39:1104–1110.PubMedCrossRefGoogle Scholar
  3. 3.
    Murphy EL, Glynn SA, Fridey J, et al. Retrovirus Epidemiology Donor Study (REDS) Study Group. Increased prevalence of infectious diseases and other adverse outcomes in human T-lymphotropic virus types I- and II-infected blood donors.J Infect Dis. 1997;176:1468–1475.PubMedCrossRefGoogle Scholar
  4. 4.
    Oguma S, Imamura Y, Kusumoto Y. et al. Stable human T-lymphotropic virus type I carrier rates for 7 years among a teenaged blood donor cohort of 1986 in Kumamoto, Japan.Leuk Res. 1995;19:567–571.PubMedCrossRefGoogle Scholar
  5. 5.
    Etoh K, Yamaguchi K, Tokudome S, et al. Rapid quantification of HTLV-I provirus load: detection of monoclonal proliferation of HTLV-I-infected cells among blood donors.Int J Cancer. 1999;81:859–864.PubMedCrossRefGoogle Scholar

Copyright information

© The Japanese Society of Hematology 2002

Authors and Affiliations

  • Kazunari Yamaguchi
    • 1
    • 2
  • Toshiki Watanabe
    • 1
    • 2
  1. 1.Kumamoto University School of MedicineKumamoto
  2. 2.Division of Pathology Department of Cancer Research, Institute of Medical ScienceUniversity of TokyoTokyoJapan

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