Lack of BLV and PTLV DNA sequences in the majority of patients with large granular lymphocyte leukaemia

The primate T-cell lymphoma/leukaemia viruses (PTLV) and bovine leukaemia v irus (BLV) comprise a unique genus of retroviruses, infection with which in duces seroreactivity in the host against conserved epitopes in their p24 ga g and gp21 env cognate proteins. Herein, we have confirmed this serocrossre activity. Patients with large granular lymphocyte (LGL) leukaemia have freq uent seroreactivity to the p24 and gp21 env proteins of human T-cell lympho ma/leukaemia virus I (HTLV-I), one of the species in the genus. However, on ly a small minority of patients are actually infected with prototypic HTLV- I or HTLV-II, another species within the group. In an attempt to determine whether LGL leukaemia might be associated with other members of the PTLV/BL V genus, we examined the peripheral blood mononuclear cell DNA of 22 HTLV p 24 and/or gp21 seropositive LGL leukaemia patients via PCR using degenerate and specific primer pair/probe systems capable of detecting all known memb ers of the PTLV/BLV genus. None of the samples was positive, These data ind icate that although HTLV-II may be associated with some cases of LGL leukae mia most patients are not infected with a PTLV or BLV virus.