Incidence of Hairy Cell Leukemia, Mycosis Fungoides, and Chronic Lymphocytic Leukemia in First Known HTLV-II-Endemic Population

Unlike human T cell leukemia-lymphoma virus type I (HTLV-I), HTLV-II has not been convincingly linked to a malignancy. In the first 10 months of serologic screening for HTLV-I/II among blood donors in New Mexico in 1988–1989, HTLV-IIII infection was found in 27 donors. HTLV-IIII infection waspresent in 1.0%–1.6% ofAmerican Indian and 0.16%–0.27% of Hispanic donors compared with 0.009%–0.06% of non-Hispanic white donors. HTLV-II was identified by DNA amplification in 12 of 13 samples from Indian and Hispanic seropositive donors. Despite apparent endemic HTLV-II infection in these populations, New Mexico Tumor Registry data showed that the incidences of hairy cell leukemia, mycosis fungoides, and chronic lymphocytic leukemia were comparable among the three ethnic groups. A population with endemic HTLV-II infection has been identified, and there is no evidence of increased risk for these three malignancies in the endemic groups.