Prevalence of human T-cell lymphotropic virus type 1 and 2 among patients with malignant hematological diseases in south Chile.

Human T-cell lymphotropic virus type 1 and 2 (HTLV-1/2) are oncogenic retroviruses linked etiologically to human diseases. In Chile, these viruses have been studied in ethnic populations, or patients diagnosed clinically with HTLV-1 associated myelopathy/tropical spastic paraparesis, but have not been studied in patients with malignant hematological diseases. The aim of this study was to determine the seroprevalence and viral prevalence of HTLV-1/2 among patients with malignant hematological diseases. Eighty-eight patients with malignant hematological diseases were tested by enzyme-linked immunosorbent assay (ELISA) for IgG anti-HTLV-1/2 and nested-PCR for the tax gene. The seroprevalence by ELISA was 3.4% and the viral prevalence by nested-PCR tax was 18.2%. HTLV-1 was found in 17% and HTLV-2 in 1% of the patients tested. HTLV-1/2 was found in 17.4% of patients with non-Hodgkin's lymphomas, 28.6% of patients with Hodgkin's lymphomas, 80% of patients with chronic lymphocytic leukemia, 11.4% of patients with acute lymphoblastic leukemia, and 22.2% of patients with acute myeloid leukemia. A high prevalence of HTLV-1/2 was found in patients with malignant hematological diseases. A high proportion of patients were seronegative to HTLV-1/2 infection, similar to other HTLV-1/2 associated disorders. Because 50% of patients positive for HTLV-1/2 were below 30 years old, it is suggested that vertical transmission could have played an important role in these patients.