Clinical aspects of adult T-cell leukemia/lymphoma (ATL)

We screened serum samples from patients with various hematological disorders and healthy individuals for the presence of adult T-cell leukemia/lymphoma associated antigen (anti-ATLA) antibodies. These antibodies were detected not only in all patients with ATL but frequently in those diagnosed as T-cell malignant lymphoma or T-cell chronic lymphocytic leukemia; the positivity rate of anti-ATLA antibody was lower in B- and null-cell-type lymphoma, B-cell chronic lymphocytic leukemia, and multiple myeloma. Patients with aplastic anemia or acute leukemia who had received frequent and massive blood transfusions also possessed anti-ATLA antibodies. About 5.5% of the healthy individuals over 40 years of age in the endemic area (Kumamoto) were carriers. The rate of positivity gradually increased with age, and was higher in females than in males. In addition, the peripheral blood mono-nuclear cells and/or lymph node cells from patients with various hematological disorders, including ATL, were examined. The presence of human T-cell leukemia/lymphoma virus type I (HTLV-I) proviral DNA was confirmed in all patients with ATL and in some with T-cell-type malignant lymphomas. However, in HTLV-I carriers or other patients with hematological disorders without ATL, proviral DNA was not detected. In endemic areas, detection of proviral DNA is essential for the classification and diagnosis of T-cell malignancies.