Examination of HTLV-I ELISA-Positive Leukemia/Lymphoma Patients by Western Blotting Gave Mostly Negative or Indeterminate Reaction

Abstract

We used enzyme-linked immunosorbant assay (ELISA) and Western blotting, with "purified" human T-cell leukemia virus I (HTLV-I), to test for HTLV-I antibodies in 2583 plasma samples from 1053 leukemia/lymphoma patients treated at Roswell Park Memorial Institute, mostly between 1972 and 1984, and in 110 sera samples from normal healthy persons. The results demonstrate that ELISA and Western blot assay have limitations for HTLV-I antibody detection in an adult T-cell leukemia/lymphoma (ATL) nonendemic population. This conclusion is based on the many false reactives obtained by ELISA, and weak and indeterminate reaction (mostly p19 band) on Western blotting. All moderate to strongly HTLV-I ELISA-positive samples tested were negative for human immunodeficiency virus (HIV) antibodies. Although 6/27 mycosis fungoides (MF) patients tested gave mostly a weak reaction on HTLV-I ELISA, 3/6 MF patients gave multiple bands (p19, p31, p36, gp46) on Western blotting and three samples from one patient gave the same p31, p36, and gp46 bands. This may suggest involvement of some HTLV-I-related virus in MF. These results also indicate that prevalence of HTLV-I infection in leukemia/lymphoma patients was rare, if it exists at all, since, despite the reactivity of some sera with HTLV-I-suspected antigens, none of the samples satisfy the USPHS criteria for positivity which is based on the detection of antibodies to gag protein p24 and to an env gene product gp46 or gp61/68.