Failure to detect human T-lymphotropic virus type-I proviral DNA in cell lines and tissues from patients with cutaneous T-cell lymphoma

Previous molecular studies investigating the presence of HTLV-I proviral DNA in cell lines and tissue samples of patients with cutaneous T-cell lymphoma (CTCL) have reported a detection rate ranging from 0-92%, Despite the lack of epidemiologic data linking HTLV-I infection with CTCL, the molecular data still invite speculation regarding the precise role of HTLV-I in the pathogenesis of CTCL, To determine the detection rate of HTLV-I proviral DNA among CTCL patients referred to our medical center, we analyzed Epstein-Barr virus-transformed cell lines established from peripheral blood of seven CTCL patients and 43 tissue samples from 22 patients with different stages of disease. Genomic DNA was polymerase chain; reaction-amplified with primers within the HTLV-I fax gene region, Amplification products were probed with nested oligonucleotide probes by Southern blot analysis, No HTLV-I proviral sequences were detected in the samples (0/50), Using HTLV-I/II pol primers, no HTLV-I pol gene sequences were detected, In tissues from one patient, HTLV-II pol and fax gene sequences were detected; however, HTLV-II proviral integration was not detected by Southern blot analysis of the genomic DNA, Our data suggest: (i) HTLV-I does not appear to be a primary etiologic agent in CTCL; and (ii) HTLV-II pol and tax gene sequences can be detected in a minority of CTCL patients, but this does not necessarily imply an etiologic role.